Lipodystrophy type 3 (FPLD3) has been described as molecularly associated with the PPARG gene, with predominantly missense variants on chromosome 3. The syndrome causes loss of adipose tissue in the upper and lower limbs, hips, and face. It is generally associated with metabolic disorders such as type 2 diabetes, insulin resistance, hypertriglyceridemia, and liver dysfunction. Therefore, the objective of this work was to molecularly diagnose and characterize the genotype/phenotype of patients with a clinical diagnosis of LPF3 recruited by the endocrinology clinic of the Hospital Universitário Onofre Lopes.To this end, a clinical evaluation was carried out, oral swabs and blood samples were collected. Biochemical analyses and dosages of the hormones adiponectin and leptin were performed using the ELISA technique to evaluate the metabolic disorders inherent to FPLD3. The next-generation sequencing (NGS) technique was chosen to diagnose the variants through a panel of genes related to lipodystrophies including LMNA and PPARG. To confirm the NGS data, amplification of genetic material was carried out by conventional PCR and Sanger sequencing using primers specifically designed for this work. The tools used for bioinformatic analysis of the variants were Poly-Phen2, TCoffee, and Mutation Taster. It was observed that the patients presented clinical characteristics compatible with the presence of lipodystrophy, such as loss of adipose tissue in the extremities, hypertriglyceridemia, and steatosis, in addition to a reduced adiponectin and leptin dosage within normal limits concerning the reference value for the index of corresponding body mass. Molecularly, new heterozygous variants located at positions c.533T>C promoting the replacement of the amino acid leucine by proline at 178 (p.Leu178Pro) and c.641C>T promoting the replacement of the amino acid proline by leucine at 214 were identified and confirmed in three patients. (p.Pro214Leu). The variants respectively affect the DBD domain of the protein, responsible for binding PPAR to the promoter region of target genes, and the Hinge region, involved in the interaction with coactivators and corepressors. Through bioinformatic analysis of each identified variant and its comparative alignment with the wild type, it was observed that the scores corroborated what was observed clinically, classifying the variants as harmful to their function. This was the first study to molecularly characterize patients with familial partial lipodystrophy type 3 in Brazil and the first to report the c.533T>C and c.641C>T variants in the global literature.

Diseases caused by pathogenic fungi have a substantial impact on both immunocompromised and immunocompetent patients, requiring lengthy treatments that, in some cases, demand hospitalization. In this regard, species and/or genotype-specific diagnosis can enhance disease prognosis, enabling a more targeted treatment depending on the etiological agent. Nevertheless, comparative studies on parasitism relationships involving closely related fungal species, often cryptic within the same genus, are still scarce. Species-specific virulence categorization directly impacts therapeutic direction and clinical prognosis, thereby optimizing case resolution. Consequently, the gold standard model for assessing the virulence of these pathogens is the murine model. However, currently, due to increased concerns about bioethical and financial issues, invertebrate animals have been proposed as attractive alternatives for infection models, given their innate immunity evolutionarily close to mammals, infrastructural ease, and robust data reproducibility. In this study, the virulence of different species of medical importance, from both clinical and environmental clades of the dimorphic fungus genus Sporothrix, as well as aspects of the innate immune response, were assessed in the invertebrate model Tenebrio molitor, in both the mycelial and yeast phases of the fungus. Thus, it was possible to compare virulence profiles and the host-parasite relationship among isolates of species within the genus. Significant differences were observed between the mycelial and yeast phases of pathogenic species from both Sporothrix clades. The species S. chilensis and S. pallida (environmental clade) demonstrated higher virulence in the mycelial morphology, whereas the species S. schenckii and S. brasiliensis (clinical clade) showed higher virulence in the yeast morphology. The expression of antimicrobial peptides (AMPs) from the invertebrate model was quantified, showing a significant difference in expression between groups infected with S. pallida and S. schenckii, indicating alterations in the pattern of the innate immune response concerning the Sporothrix species inoculated into the model.

Plants are subjected to daily environmental changes and must respond optimally to tolerate these modifications. Alterations in gravity, hypoxia, and heat are examples of environmental changes that can induce abiotic stress, primarily triggering oxidative signaling. Since microgravity is not a condition naturally occurring on Earth, some exposure methods are required to place plants in environments with gravity approaching zero. The use of international space stations and space flights are ways to expose plants to this type of environment. However, there is still no consensus on all the effects that microgravity may trigger. Thus, comparing microgravity studies with other environmental factors can enhance understanding of plant responses to microgravity. In this context, the integration of transcriptomic data from studies available on open-access platforms was performed, investigating the impacts of microgravity, hypoxia, and thermal stress on plants. Since these environmental conditions may share oxidative signaling pathways, the objective of this integration was to enrich the understanding of plant responses to microgravity, heat, and hypoxia in a comparative manner, as well as to explore the differential and correlated effects of microgravity in international space station and space flight settings. Therefore, bioinformatics tools were employed to identify significantly activated central genes, ontologies, and metabolic pathways. For data integration, a selection was made according to inclusion and exclusion criteria. For example, studies should clearly state experimental conditions and compare stressed and non-stressed plants. Consequently, 16 microgravity studies were selected, including 11 from international space stations and 6 from space flights, along with 10 thermal stress studies and 9 hypoxia studies. This integration revealed significant regulation of genes related to chlorophyll biosynthesis. These results suggest that photooxidation may be an important effect under microgravity, hypoxia, and heat conditions. This effect appears to be independent of microgravity exposure type. There was also an overlap in the activation of antioxidant metabolic pathways: glutathione metabolism and phenylpropanoid biosynthesis, demonstrating that plants employ redox homeostasis pathways using different strategies. Primary metabolism, specifically through the production of sugars such as starch and fructose, is significantly affected under hypoxia, heat, and microgravity conditions. These sugars are essential for energy production, carbon metabolism, and gravity signaling. Therefore, oxidative signaling triggered by microgravity, heat, and hypoxia significantly affected chlorophyll production and primary metabolism; however, this impact may be mitigated by intense antioxidant activity. Comparing these responses to those induced by other environmental stresses provides important insights into the adaptive capacity of plants in environments with different gravitational forces. Such understanding is crucial for developing strategies to enhance crop resilience in terrestrial and space agriculture contexts.

Fungal infections represent a major contributor to the increasing global mortality rate associated with infectious diseases. This increase is largely attributed to the indiscriminate use of antibiotics and antifungals agents, whose effectiveness is compromised by the development of resistance in pathogens and the adverse effects observed in non-target organisms. Botanical extracts and their fractions have been highlighted as promising sources for the development of antifungals and therapeutic adjuvants for reference drugs as they are derived from renewable sources and present toxic selectivity. Tephrosia toxicaria (Sw.) Pers, a legume well adapted to the northeastern semi-arid region, has stood out for its biopotential. The present research aimed to investigate the antifungal potential of extracts and protein fractions obtained from T. toxicaria seeds against species of the Candida and Cryptococcus genera and their modulating activity for reference antimicrobials. The extracts and fractions obtained by the Scopes and Osborne methods were partially biochemically characterized and evaluated for their antifungal activity by determining the MICs (Minimum Inhibitory Concentration). Subsequently, the most active fraction and its combinations were also investigated regarding their possible mode of action. The extracts and fractions showed antifungal activity to different degrees for at least one of the yeasts tested, in which the T 50-75 fraction was the most active against Cryptococcus gattii, Cryptococcus neoformans and Candida parapsilosis and the GLB fraction against Candida albicans. The lowest MIC₁₀₀ values (MIC, capable of inhibiting 100% of growth) found were 32 µg/mL for the T 50-75 fraction against Cryptococcus gattii (R-265), 128 µg/mL for the ST extract and 256 µg/mL for fractions T 50-75 and T 75-100, all against C. gattii (FC1). The ST extract and the fractions T 50-75 and T 75-100, as they presented the lowest MIC₁₀₀ values, were selected to investigate their modulating potential in combination with Amphotericin B, Fluconazole and 5-Flucytosine, using the association method (checkerboard) by FICI (Fractional Inhibitory Concentration Index) and by mathematical models (Blis, HSA, Loewe and ZIP). All tested combinations were able to reduce the MIC₁₀₀ for C. gattii and after data harmonization, the combinations between the T 50-75 and T 75-100 fractions with Amphotericin B and Fluconazole were classified as synergistic, however the combinations with the fraction T 50-75 showed greater sensitivity (93%) and degree of synergistic intensity. The combination of the fraction T 50-75 with the drugs caused greater interference in the growth curve, melanization and a significant reduction in capsule size. However, exposure of C. gattii to treatment with only the T 50-75 fraction also caused morphological changes in the cell wall and capsule, indicating that the fraction contributed strongly to the result observed in combination with the drug. Therefore, the T 50-75 fraction presents itself as a promising candidate for the development of adjuvants and/or new drugs for antifungal chemotherapy. Analysis of the results suggests that the fungistatic action of the T 50-75 fraction can contribute to minimizing the emergence of resistance in the pathogen, acting in redundant pathways and reducing the effective concentrations of clinical reference drugs, thus improving treatment and minimizing toxicity generated.

Chagas disease (DCh) is caused by the parasite Trypanosoma cruzi (T. cruzi) and is characterized by two clinical phases: acute and chronic. During the acute phase, the parasite targets specific tissues and dysregulates cytokines and matrix metalloproteinases (MMPs), which are major risk factors for the development of cardiopathies, common complications in both the acute and chronic phases of the disease. This study aimed to optimize gel-based methods, such as SDS-PAGE and zymography, to evaluate whether T. cruzi infection could alter the metalloproteinase profile of key organs during the acute phase of DCh. For this purpose, total protein extract from epimastigote forms of T. cruzi Y strain from axenic culture was obtained, and experimental infection with blood trypomastigote forms was performed in female mice, divided into three groups: uninfected (CN, negative control, n=3) and infected, euthanized at 17 (D17, n=3) and 32 (D32, n=3) days post-infection. Control animals were used as a baseline for comparison with infected animals. Heart, spleen, liver, and blood from all groups were collected to produce total extract and blood plasma. Optimization allowed the determination of the protein profile of T. cruzi, revealing bands with approximate molecular weights of 95, 85, 63, 57, 48-52, 43-45, 40-41, 29, and 18-20 kDa, which were discussed in terms of their possible identification and function in the infection. The results also demonstrated the protein profiles of cardiac, splenic, hepatic tissues, and plasma in the three analyzed groups. The T. cruzi zymogram revealed three activity bands with approximate molecular weights of 66 kDa, 55 kDa, and 35 kDa, along with a faint activity band between 66 and 35 kDa. In the infected animal group, clinical signs of hepatomegaly and splenomegaly characteristic of the acute phase of DCh were observed. Several gelatin-degrading metalloproteinases were detected in the zymogram of tissues and plasma, especially in splenic tissue. Differences in their expression during acute infection were observed only in splenic and cardiac tissues, with the alteration in cardiac tissue related to the increased expression of a 93 kDa protease, likely proMMP-9, and in the spleen, a 146 kDa unknown protease. In summary, the findings provide information on the protein and proteolytic expression patterns for T. cruzi and the analyzed organs plus plasma, revealing abundant proteins as potential immunogenic targets against T. cruzi. These data serve for comparison of the genetic and functional diversity of the parasite along with other studies, besides confirming changes in protease expression during the acute phase of DCh, opening avenues for diagnostics and treatment based on the necessity and feasibility of inhibiting these proteins.

Infections have become a worrying threat to public health, especially when caused by bacteria resistant to currently available antimicrobials. This thesis aimed to study new alternatives for treatments against bacterial infections. For this purpose, a narrative review and an in vitro and in vivo study were performed. Thus, the first chapter of this thesis presents a narrative review of new biomedical alternatives in antibacterial treatments. As a result, it was found that some areas of research aiming to control bacterial infections have been highlighted, namely bioinformatics, nanotechnology, and genomics, in addition to studies developed with natural molecules such as antimicrobial peptides. Furthermore, the articles in this narrative review presented promising research in developing antimicrobial agents, and their mechanisms of action and strategies to minimize the consequences of bacterial resistance. The review will present current alternatives may contribute to future studies in the area. In the second chapter, the effect of trypsin inhibitor isolated from tamarind seeds (TTI) on the survival of Caenorhabditis elegans (C. elegans) (wild strain) under conditions of bacterial infection was investigated. The TTI was isolated in Trypsin-Sepharose CNBr-4B affinity chromatography. Its protein quantification was performed using the Bradford method, and an antitryptic assay monitored its specific activity. The animals were maintained in Nematode Growth Medium (NGM) and Escherichia coli bacteria (OP50) as a food source at 20 ⸰C and, for the analysescarried out, they were previously exposed to different concentrations of TTI, from stage L1 to L4, in addition to a group control without treatment. Besides, the toxicity test was performed by evaluatingoviposition, progeny, locomotion, and body size. Subsequently, the bacterial infection test was carried out with Staphylococcus aureus in C. elegans previously subjected to concentrations of 0.1 and 1.0 mg/mL of TTI. Nematodes were exposed to the stressor tert-butyl hydroperoxide (TBOOH) in an oxidative stress test. Then, bacterial growth curve and antioxidant and antibacterial activity tests were carried out in vitro. In the toxicity test, no statistical difference was found between the control group and the other concentrations tested (p> 0.05). Regarding body size, the tested TTI concentrations showed a statistical difference (p<0.05) and presented higher length than the untreated group. Regarding bacterial infection analyses, animals subjected to 0.1 mg/mL and 1.0 mg/mL of TTI showed survival of 16.10% and 30.32%, respectively, higher than the group infected without treatment (8.08%). To understand the role of TTI on animal survival, in the oxidative stress test, at all tested TTI concentrations, greater survival was observed about the control at 12h and 18h (p< 0.05). In in vitro studies about the bacterial growth curve, no inhibitory activity of TTI was observed about Escherichia coli (OP50) (p>0.05) at the concentrations tested, nor was antibacterial and antioxidant activity observed. Given the results, a greater survival of C. elegans was found when previously exposed to TTI; however, in a different antioxidant and antibacterial pathway. In this way, the study contributed to consolidating theoretical and scientific understanding through narrative review and ITT tests, respectively, on new alternatives for controlling bacterial infection.

Obesity is a complex disease and mostly polygenic disease. In this context, several trea-
tments are listed to mitigate it and nutritional genomics has been gaining prominence with
possible tools to assist in the prevention and/or treatment of obesity with nutrigenetic testing
(NT) . Therefore, this thesis is divided into two chapters, aiming to evaluate whether NT can
be used to prevent and/or treat obesity. In the first chapter, a narrative review was carried
out to understand the current panorama of obesity and NT, covering the themes of precision
nutrition, exposome, genetic testing sold directly to the consumer. The benefits and nega-
tive aspects of using NT as a tool to help prevent or treat overweight and obesity were
analyzed. Some entities, such as the Brazilian Association for the Study of Obesity and
Metabolic Syndrome (ABESO) are against the use of NT for obesity. The Academy of Nu-
trition and Dietetics recommends its use, however not in isolation, but within a context of
well-conducted anamnesis. Therefore, NT should not be used alone in the treatment of
obesity, but always associated with a good anamnesis for the individualized treatment of
obesity or at a public health level. In the second chapter, a retrospective study was carried
out, evaluating the relationship of 29 candidate gene SNP related to obesity. Thus, 112
individuals were divided into two groups: 64 eutrophic (BMI< 25 kg/m²) and 48 overweight
and obese (BMI≥ 25 g/m²). It was verified that the population was in Hardy–Weinberg equi-
librium and a multivariate logistic analysis was performed to verify whether the SNP were
associated with overweight and obesity. In this analysis, it was found that of the 29 SNP
found in NT marketed in Brazil, only ADIPOQ rs17300539, PPARG rs1801282 were asso-
ciated with overweight and obesity, while SOD rs4880 was related to protection against
overweight and obesity. Thus, it was shown that more studies are needed to validate which
SNP are related to overweight and obesity in the Brazilian population. Furthermore, lifestyle
analysis must be added, as these factors can epigenetically alter gene expression and im-
pact the phenotype.

Bacterial resistance, as well as inflammatory disorders, are significant public health problems that take thousands of people to hospitals every year, often requiring several days of hospitalization for treatment, generating excessive costs and, sometimes, without solving the problem. Considering the importance of discovering new substances that mitigate these problems, this study aimed to evaluate the crude extract and protein fractions of the seed of Poincianella pyramidalis (Tul.) for antibacterial, antibiotic-modulating, and protease-inhibiting activities. The protein extracts were obtained from extraction with 0.05M Tris-HCL buffer pH 7.5 and subsequent fractionation with ammonium sulfate in different saturation ranges 0-30%, 30-60% and 60-90% of sodium sulfate ammonium. The electrophoretic profile revealed several protein bands between 12 KDa and 225 KDa. The inhibitor-enriched fraction (FE) was obtained using only a Trypsin-Sepharose affinity chromatography after extraction. The antimicrobial activity test was performed through the microdilution assay and the modulating action of the antibiotics ampicillin, norfloxacin and gentamicin, using a subinhibitory concentration MIC/8. Although the samples did not show direct antimicrobial action against the ATCC strains Escherichia coli, Staphylococcus aureus and methicillin-resistant S. aureus (MRSA), it was observed that, at a concentration of 128 µg/mL, the samples associated with the different antibiotics (aminoglycoside, β-lactam and fluoroquinolone) had a synergistic action against the multiresistant strains of E. coli, S. aureus and Pseudomonas aeruginosa. While the other samples inhibited the action of the serine proteases tested in percentages above 80%, FE reduced 50% of the activities of the enzymes trypsin, human neutrophil elastase (HNE) and chymotrypsin, at concentrations of 0.017, 0.023 and 0.156 µg/µL, respectively, and its antitrypsin activity was maintained at high temperatures (80 ºC) and a wide pH range (2 to 12). No hemolytic activity was observed at concentrations up to 10x higher than the IC50, thus enabling its use in possible pharmacological preparations. In this way, we were able to separate, in a relatively simple way, products derived from P. pyramidalis seeds with relevant activities in the clinical context, considering their potential application in combating infections caused by resistant bacteria, as well as in inflammatory protease disorders, and with reduced treatment costs.

Oxidative stress is a crucial physiological process involved in regulating and maintaining several fundamental processes in organisms, as well as in diseases such as cardiovascular diseases, neurodegenerative diseases, and cancer. There is growing interest in identifying new molecules, particularly from natural sources, that possess antioxidant properties. Marine macroalgae have emerged as functional foods and sources of active molecules with various properties, including sulfated polysaccharides (PS). One example is PS fucoidan A (FucA), extracted from the algae Spatoglossum schröederi, which has been studied for its antithrombotic, anti-inflammatory, and non-genotoxic potential. However, FucA does not exhibit significant antioxidant activity. The presence of antioxidant properties could enhance the effects of the biological activities already identified. One strategy to enhance the effects of a molecule is through chemical modification by adding functional groups and developing blends that combine the properties of two components. To improve the antioxidant activity of FucA, factorial design and response surface plots were employed to develop blends containing FucA and dextran modified with gallic acid (Dex-Gal). Chemical and structural analyses confirmed that Dex-Gal was modified with the addition of 3% GA and exhibited a total antioxidant capacity (TAC) 3.2 times higher than that of unmodified Dex. Dex-Gal and FucA were subjected to factorial design to create different proportions and develop five blends (BLD1, BLD2, BLD3, BLD4, and BLD5). Two blends, BLD1 and BLD5, demonstrated low activity in the antioxidant tests performed. In the TAC test, three blends stood out: BLD4 (22 Eq. AA), BLD3 (17 Eq. AA), and BLD2 (13 Eq. AA). In the reducing power test, BLD4 showed a reduction of 28%, compared to 17% for BLD2 and 15% for BLD3. Notably, BLD4 also excelled in the hydroxyl radical scavenging test, demonstrating approximately 100% activity. Analysis of the surface graphs confirmed that the ideal proportion of the FucA and Dex-Gal blend is that formulated in BLD4, with a 1:1 ratio of each component. BLD4 was selected for antioxidant tests in the 3T3 cell line, as well as in biological models of Caenorhabditis elegans and zebrafish (Danio rerio). BLD4 did not exhibit cytotoxicity in 3T3 cells and provided protective effects against oxidative stress induced by H2O2; it enhanced the survival of C. elegans larvae under oxidative stress with T-BOOH and reduced intracellular ROS by 30%; it also protected zebrafish embryos from oxidative stress caused by H2O2. In both cellular and C. elegans models, BLD4 performed better compared to its isolated components.

The species complexes of Cryptococcus neoformans and Cryptococcus gattii are composed of pathogenic fungi that kill over 180,000 people annually worldwide, having meningoencephalitis as the main symptom of cryptococcosis. Characteristics such as virulence and antifungal susceptibility can vary within each species according to fungal genotype: C. neoformans is divided into molecular types VNI, VNII, VNIII, and VNIV, and C. gattii into VGI, VGII, VGIII, and VGIV. Therefore, specific molecular markers are necessary for differential diagnosis. Autocatalytic group I introns can be a potential target for distinguishing between molecular types of these yeasts, as they have polymorphisms regarding their presence and base pair sequences. Furthermore, since the auto-splicing of these elements is vital for the fungal cell, they are considered important therapeutic targets since they are absent from the human genome. Therefore, this study aimed to evaluate the presence of group I introns in the mitochondrial cob and cox1 genes of Cryptococcus fungal isolates, search for ORFs with endonuclease genes in intronic sequences, investigate the potential use of these genetic elements as molecular markers for differentiation of genotypes and/or species, and analyze their relationship with antifungal susceptibility andin addition to study their origin, distribution, and evolution through phylogenetic analyses. The data obtained from intron amplification of cob and cox1 genes showed that the C. neoformans complex has, on average, fewer introns in its mitogenome, and there is a great polymorphism of presence and size of these elements among and within genotypes, making it impossible to use a single intronic marker to differentiate genotype and/or species in the C. neoformans and C. gattii complexes. However, differentiation between species is possible with combinations of PCRs of mtLSU and cox1 introns for C. neoformans species and mtLSU and cob introns for C. gattii. Approximately 80.5% of the sequenced introns had homing endonucleases, and phylogenetic analyses showed that introns occupying the same insertion site form monophyletic clades and probably have a common ancestor that invaded this site before the species diverged. There was only one case of heterologous invasion, probably originating from horizontal transfer between a VGIV genotype isolate and the lichenized fungus Arthonia susa. Regarding susceptibility assays to antifungal agents, it was observed that the minimum inhibitory concentration (MIC) values of Fluconazole, 5-Flucytosine, and Pentamidine were statistically associated with species complexes, with C. gattii having higher MICs for Fluconazole and C. neoformans having higher MICs for 5-Flucytosine and Pentamidine. The presence of introns was related to susceptibility to Amphotericin B, for which a higher number of introns was associated with lower MIC values, and to 5-Flucytosine and Pentamidine, for which the influence of the presence of introns varied between complexes: regarding 5-Flucytosine, the presence of introns was related to lower susceptibility in C. neoformans and higher in C. gattii, and the opposite scenario was observed for Pentamidine, for which introns were associated with higher susceptibility in C. neoformans and lower in C. gattii.

Cantaloupe melon has an orange pulp rich in carotenoids, which can promote several beneficial effects on human health. However, carotenoids are extremely unstable in the presence of oxygen, light, and heat, which may reduce their bioactive properties. In this context, nanoencapsulation is an excellent strategy to ensure the preservation and enhancement of bioactive effects. On the other hand, one of the major current concerns is related to the toxicity effects of these nanoparticles. Therefore, this study aimed to evaluate the teratogenicity of the crude extract rich in carotenoids from Cantaloupe melon (CE) and of the porcine gelatin-based nanoparticles containing CE (EPG) in an animal model of zebrafish (Danio rerio). The CE was obtained from Cantaloupe melon (Cucumis melo L.) in processes that involved drying the melon pulp (55 ̊C/24 h) to obtain flour, maceration in ethanol (1:4 w/v) and partition in hexane (1:1 v/v). The nanoparticles were obtained using the oil-in-water (O/W) emulsification technique. For the characterization of nanoparticles in terms of morphology, chemical interactions, particle size and encapsulation efficiency, Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Laser Diffraction and Incorporation Efficiency (IE) analyses were carried out (IE), respectively. In the experiments in an animal model with zebrafish, for the embryotoxicity test, the 308 embryos, divided into seven groups, were exposed to concentrations of 12.5 mg/L and 50.0 mg/L of CE and EPG during 96 hours post fertilization (hpf) and seven days post fertilization (dpf) the optomotor test was performed. In the toxicity tests with adult zebrafish, the 60 fish were divided into six groups exposed to 12.5 mg/L and 50.0 mg/L of CE and EPG for 96 hours, and then submitted to light/dark neurotoxicity, new and social tank. Based on the characterization results, EPG showed an IE of 94% (4.04), a smooth surface without depressions, a diameter of 88.7 nm (7.02), and a polydispersion index of 0.41 (0.03). FTIR evidenced the emergence of new vibrational bands in EPG compared to CE, demonstrating new chemical interactions. In animal model experiments, no anomalies were observed after exposure to 96 hpf, in the groups treated with CE and EPG, and heartbeats remained between 132 and 138 rpm within the expected range for embryos, similar to the negative control and DMSO groups. The groups that received CE and EPG did not show significant morphological alterations. The mortality level was below 20%, revealing neither an embryotoxic nor teratogenic character for CE and EPG in the concentrations used. There was a significant improvement in the visual motor response of larvae exposed to CE and EPG, which can be attributed to the antioxidant power and vitamin A precursor of carotenoids. No adverse effects were identified on the behavior of adults, all were similar to the behavior of the control group, without signs of anxiety, stress, or changes in swimming, speed or sociability that would indicate any toxicity. Therefore, it was found that CE and EPG maintained characteristics found in previous studies, proving the method's reproducibility. There were no signs of teratogenicity, cardiotoxicity, or neurotoxicity in the larvae, and both CE and EPG improved cognitive function and response in the evaluated model. Adult fish showed no signs of anxiety or any other evidence of toxicity, showing that CE and EPG are potentially safe.

Marine sponges are very promising organisms in the search for bioactive molecules with a range of biological activities already reported in the scientific literature, with an emphasis on antioxidant agents. Knowing that oxidative stress is associated with various health conditions, such as cancer, Parkinson's, Alzheimer's, among others, the search for compounds that act on oxidative control becomes a key element in the quest for new treatments. The Potiguar Basin of RN has a vast coastline with a rich diversity of marine sponge species, but, on the other hand, it is little explored in terms of its biotechnological potential. In this work, we conducted chemical, antioxidant, and toxicological prospecting of three species of sponges collected on the coast of the Potiguar Basin: Suberites aurantiacus, Mycale (Zygomycale) angulosa, and Halichondrida. Sequential extractions were carried out with n-hexane (HE) and chloroform/methanol, and the extracts obtained only with HE were named HESUB, HEMYC, and HEHALI, while the extracts obtained only with CM were named CMSUB, CMMYC, and CMHALI for S. aurantiacus, M. angulosa, and Halichondrida, respectively. The yield of the extracts was the determining factor for choosing the CM extracts that would be chemically characterized by GC/MS and evaluated for their antioxidant activity using the following methods: Total Antioxidant Capacity (CAT), Reducing power, ion sequestration (superoxide, DPPH, Hydroxyl Radical (OH)) and Ion Chelating activity (Ferrous (Fe²⁺) and Cuprous (Cu²⁺)). CM extracts from the three sponges were also subjected to toxicological tests in vitro with human erythrocytes and in vivo with Tenebrio molitor larvae. Chemical characterization by GC/MS revealed the presence of alcohols, alkaloids, phenolic compounds, and lipids (mainly sterol classes). In in vitro antioxidant tests, the extracts showed the ability to scavenge DPPH radicals (CMHALI 60.91% ± 3.05; CMSUB 59.32% ± 3.71 and CMMYC 53.78% ± 6.96 at 1000 µg/mL) and hydroxyl radicals (CMSUB 96% ± 0.04 at a concentration of 2000 µg/mL; CMMYC 37% ± 0.17 and CMHALI 54% ± 0.086 with 1000 µg/mL of extract) and chelating copper ions (CMHALI 113.5% ± 1.93; CMSUB 112.1% ± 5.81 and CMMYC with 110.6% ± 3.19 activity with 25 µg/mL of the sample), with a particular emphasis on the copper chelating activity for three extracts. In vitro and in vivo toxicological tests revealed that, in both tests, at different concentrations, the samples did not exhibit toxic effects. Furthermore, antibacterial tests were conducted against the pathogenic bacteria Staphylococcus aureus and Escherichia coli, but no such activity was observed. The results presented here suggest that marine sponges from this coast have pharmacological properties that can be investigated with a view to isolating the metabolites responsible for the antioxidant activities presented. Furthermore, there is the possibility of investigating the potential of these metabolites in relation to other biological activities.

Pollution from oil can have significant and long-lasting effects on the environment. Bioremediation can be an alternative to this problem. Several studies report the biotechnological potential for bioremediation by environmental Acinetobacter baumannii. However, it is still necessary to expand the understanding of the genetic mechanisms of this species to maximize its biotechnological potential. Therefore, this work aims to characterize strains of Acinetobacter baumannii oleumficedula, identify genes related to the biodegradation of hydrocarbons, as well as their presence in degradation pathways and analyze the expression of target genes. To this end, analyzes of biosurfactant production, estimation of hydrocarbon degradation, gene expression analysis and evaluation of the strains' genome were carried out. From these analyses, it was possible to verify the efficiency of all strains in the production of biosurfactant, the strains presented an estimate of hydrocarbon degradation that varied from 7.94 to 69.82%. Approximately 81 different genes associated with bioremediation were identified in 16 distinct metabolic pathways. The expression of 12 genes was observed, all of which were upregulated. By observing the gnomic context, the genetic similarity of the strains was verified. However, even with genetic similarities, the strains show significant phenotypic differences, which can be attributed to the presence of a master regulator or regulon. Finally, it can be inferred that all strains are promising for application in hydrocarbon degradation.

Proteins are multifunctional macromolecules and also act as sources of amino acids and energy. Protein hydrolysis also generates numerous bioactive peptides with different functions in the body. In this context, proteins are sources of biological products that can be used for the control and treatment of various human diseases, and may be candidates for the management and treatment of diseases such as COVID-19. To investigate experimental models that mimic human digestion and prospect peptides from trypsin inhibitor purified from tamarind (TTIp) seeds. The first two chapters of this study are referring to a systematic review (SR), and are organized as follows: the first chapter presents the SR protocol registered in the International Prospective Register of Systematic Reviews (under number CRD42020198709); and the second chapter is the SR of in vitro studies that used methodological procedures to mimic the gastrointestinal digestion of proteins. Articles were selected according to the study population, interventions, control, results and type of study strategy. The searches were carried out in Pubmed, Web of Science, Science direct, Embase, Virtual Health Library and Scopus databases. The methodological quality assessment was performed using the Office of Health Assessment and Translation tool. A total of 1.986 articles were selected, resulting in 20 eligible studies. In the results section, we describe the methodological procedures used in vitro to simulate the digestion of animal or vegetable proteins. The third chapter refers to an in silico prospecting study of native peptides and analogues with anti-SARS-Cov-2 potential, derived from TTIp. Native peptides were obtained from enzymatic cleavages of TTIp in silico and analogues were generated by replacing amino acids in the primary sequences of native peptides. The anti-SARS-CoV-2 potential was investigated by simulating molecular dynamics between the peptides and the binding sites of transmembrane serine protease 2 (TMPRSS2), necessary for the entry of SARS-CoV-2 into the host cell, and generated a patent application: BR 10 2022 020330 0. The best interaction potential energy occurred between TMPRSS2 and one of the native peptides obtained by cleavage with trypsin (-287.48 kJ.mol^-1) and its analogue peptide (-293.49 kJ.mol^-1). Thus, both peptides had many hydrophobic residues, a common physical-chemical property among peptides that inhibit the entry of enveloped viruses, such as SARS-Cov-2, present in drugs used to treat of diseases related to these enveloped viruses. Therefore, this research presents an expressive scientific contribution, since the SR grouped important data that will provide subsidies for development of studies related to the clinical application of bioactive peptides, concluding that, although in vitro dynamic experimental models are more accurate, static models can be used to simulate human proteolytic digestion, provided that the physiological conditions are controlled and there is a comparison with in vivo studies to ensure greater accuracy of the results. In addition, the in silico study resulted, from the cleavage of TTIp 56/287, in potential candidates for agents that inhibit SARS-CoV-2 infection, through interaction with TMPRSS2, encouraging future in vitro and in vivo investigations that aim to use the peptides prospected here as specific medicines for the treatment of COVID-19 and other diseases.

Oxidative stress is an imbalance between the production of reactive species and antioxidants. The accumulation of reactive species can result in damage to tissues and organs, and it can induce various physiological changes that compromise cellular homeostasis. This imbalance can be associated with diseases such as cardiac, neurological, and cancer. It has been observed that plants' phenolic compounds can scavenge and neutralize the excess of free radicals. C. alnifolia, the plant that is the focus of our research, is a tree from the Atlantic Forest and is known to have few ethnobotanical studies. Previous studies by our group have shown that extracts obtained from the leaves of this plant have antioxidant potential. Thus, in this work, the aim was to evaluate the antioxidant and immunomodulatory potential of the ethanolic extract (EE), aqueous extract (AE), and two fractions obtained from the aqueous extract – the ethyl acetate (AF) and butanolic (BF). These two fractions were chosen based on the profile obtained after analysis in high-performance liquid chromatography coupled to a diode detector (HPLC-DAD). In addition, these fractions were characterized here for their antioxidant potential by using in vitro assays. It was observed that both have antioxidant potential. The FB, however, displayed higher antioxidant potential compared to the FA. Within the antioxidant activity, the results obtained pointed out the chelation of copper, which had not been observed previously in the crude extract (EA). From these results, the immunomodulatory potential was evaluated through assays with the RAW 267.4 cell. First, it was verified that both the extracts and the two fractions were not cytotoxic. Then, considering the complexity of the inflammatory process, the effect of EE and EA on the production of ROS after treatment with lipopolysaccharide (LPS) was analyzed. For this, three concentrations of extracts were used (100, 250, and 500 µg/mL). Both extracts were found to be able to reduce ROS production when compared to the positive control (treated with LPS). Furthermore, the ROS reduction achieved with EE was similar to the negative control (without LPS treatment). Next, the ability of the extracts and fractions to inhibit nitric oxide production was verified. Both the extracts and the fractions were able to inhibit the production and release of NO at the three concentrations tested, in a dose-dependent manner, with a reduction of more than 50%. Moreover, the phagocytic activity was evaluated only for EE and AE. This analysis was done only at a concentration of 500 μg/mL, and a reduction in phagocytosis of 30% for EE and 50% for EA was observed. Considering that cytokines are important mediators for the immune and inflammatory response, they were evaluated using two methods such as the measurement of cytokines by flow cytometry, where there was observed an increase in IL-17, and by qRT-PCR, where there was a reduction in iNOS and IL -10 mRNA in the treatment with EE. Based on these results, the potential of extracts and fractions in cell migration was also evaluated using the NHI/3T3 cell line (fibroblasts) in cultures submitted to the wound assay. The results obtained showed that both extracts and fractions in 24 h promoted cell migration, with 60% wound closure for the extracts, and 75% for the FB fraction, while the control (no extract) migration percentage was around 40%. Therefore, the data presented here show that the EE and EA and the FA and FB fractions of C. alnifolia have antioxidant and immunomodulatory potential, as well as the ability to induce cell migration involved in the in vitro wound healing process. Besides, it was evidenced in this study important properties of extracts and fractions that have the potential to act on the dynamics of the inflammatory process and tissue damage. Consequently, both extracts and fractions have potential applications for health biotechnology.

Obesity drives the search for new strategies to combat it. In this sense, several peptides and proteins with satietogenic activity have been studied because they regulate dietary intake and body weight. Thus, this thesis is divided into two chapters. First, we sought to understand how peptides and proteins, when encapsulated, acted on satiety, impacting weight gain and the state of obesity. For this, an integrative review was carried out by searching databases, using the keywords: peptide, protein, obesity, encapsulation, and anti-obesity agents, and selecting preclinical studies that compared the effect of peptides or proteins, encapsulated or not, on satiety. A total of 836 studies were selected, of which only four articles met the review's focus under the selection criteria. Although it has been a limited number of studies, among the effects observed with the encapsulation of these molecules are the greater efficiency in reducing weight gain, changes in the function of adipose tissue, in addition to the reduction of hormone levels that modulate appetite and body weight, promoting the potentiation of the effects of these peptides and proteins when encapsulated. In the second chapter, the impact of the trypsin inhibitor isolated from tamarind seeds (TTI) was investigated compared to the same one, nanoencapsulated in chitosan and isolated whey protein (EQPI). Thus, the ECW was analyzed and exposed to different pH conditions (7.0, 3.0, and 7.0) and temperatures (37°C, 7°C and -18°C) to evaluate the interaction between the TTI and its encapsulating agents monitored by antitrypsin activity. Subsequently, a preclinical study was carried out in which Wistar rats (n = 25) with obesity induced by a high glycemic index and high glycemic load (HGLI) diet for 17 weeks were divided into five groups and evaluated for ten days, with them: no treatment (HGLI + water), treatment 1 (nutritionally adequate diet), treatment 2 (with nutritionally adequate diet and ECW/12.5 mg/kg), treatment 3 (diet HGLI and ECW/12.5 mg/kg ) and treatment 4 (diet HGLI and TTI/25 mg/kg). These groups were evaluated for dietary intake, zoometric, biochemical, and inflammatory parameters. The ECW preserved the TTI, showing no inhibition for trypsin efficiently. When subjected to the optimal condition (constant stirring at 300 rpm, for approximately 12 h, at 20°C) for the release of the TTI, it showed 100% antitrypsin activity. However, exposing ECW to different pHs, significant anti-trips activity was observed only at gastric pH for 2 h. And regarding exposure to temperatures, ECW showed high antitrypsin activity, similar to TTI (37°C for 4 h, 7°C for three days, and 7°C for 7 days), demonstrating the complete release of TTI contained in ECW. In the preclinical study, obese Wistar rats treated with ECW significantly reduced body weight change (p < 0.05) compared to treatment with TTI. It was observed that only TTI treatment led to significant changes in inflammatory parameters (p < 0.05). The effect of ECW on weight indicates that encapsulation promoted an increase in the impact of TTI with sustained release. Therefore, the encapsulation of peptides and proteins is a promising strategy for the applicability of these molecules in the treatment of diseases such as obesity.

Chagas disease is an endemic zoonosis in Latin America, mainly affecting the poorer populations. The available drugs for treating both diseases have low effectiveness against intracellular forms, high toxicity, low bioavailability, and end up being unsafe for patients' health. Therefore, for several decades, efforts have been made to evaluate the possibility of using other drugs to combat this disease. One promising candidate is sodium diethyldithiocarbamate (DETC), previously described as a highly effective compound against Leishmania sp. and Trypanosoma cruzi in in vitro and in vivo models. However, in an attempt to enhance its bioavailability and reduce potential toxicity, this study evaluated the use of a nanosystem in combination with DETC through in vitro, in silico, and in vivo approaches against Trypanosoma cruzi. n this study, the nanoparticle was nanoformulated through nanoprecipitation using PLA as a polymer and tested in vitro for physicochemical characterization, cytotoxicity, cellular penetration, and antiparasitic activity. The nanoformulated PLA-DETC was found to be stable, with an average size of <200 nm and with IPD <0.3 and a zeta potential of -20 mV. It exhibited low cellular toxicity, causing no reduction of more than 20% in cell viability, had the ability to penetrate 3T3 and RAW cells within a 24-hour period, and also inhibited almost 70% of the Dm28c strain of T. cruzi within 24 hours. Additionally, it was observed that the nanosystem was capable of inducing an almost 70% increase in reactive oxygen species inside the parasites, which is a crucial factor that can lead to the parasite's death.Furthermore, an in silico analysis revealed that DETC had a more suitable ADMET profile based on physicochemical and medicinal chemistry properties compared to traditionally used drugs against Chagas disease, indicating lower toxicity. In vivo toxicity of both PLA-DETC nanoparticles and free drug at concentrations of 300 mg/kg and 1000 mg/kg was evaluated, considering hematological, biochemical, histopathological, and physical parameters following the acute toxicity characterization recommended by OECD in test 423. The results showed minimal alterations compared to the control group. A 10% reduction in platelet levels was observed, along with a slight increase in urea and AST, and a decrease in creatinine levels. Moreover, there were no significant changes in the animals' weight, behavior, or physical parameters, aligning with the control group. Finally, infection and treatment protocols were evaluated using DETC (300 mg/kg, 100 mg/kg, 0.36 mg, and 0.18 mg) and PLA-DETC nanoparticles (0.36 mg and 0.18 mg). A statistically significant reduction was observed for DETC, which exhibited a profile similar to benznidazole at a concentration of 100 mg/kg. Additionally, during the 7-day treatment, few alterations were observed, indicating low compound toxicity.

Malaria is a parasitic disease caused by unicellular protozoa of the genus Plasmodium and occurs in more than 90 countries, with the African and Asian continents predominating. The use of antimalarial drugs is critical for both treatment and prevention of the disease. However, the parasites have begun to develop resistance to antimalarials, making current therapies ineffective in controlling the parasite. Therefore, new therapeutic approaches are needed to overcome the drug resistance of parasites and increase the efficacy of drug therapy against the disease. The aim of this research is to characterize the relationships that affect the behavior of protein-ligand complexes of enzymes from Plasmodium falciparum. The first study aims to characterize dihydroorotate dehydrogenase (DHODH) and to present the energy levels of the enzyme in the complexes with wild-type PfDHODH, with ligands DSM483, DSM557, and DSM1, and with PfDHODH with the C276F mutation together with DMS1. In the second study, tyrosine RNAt synthetase (TyrRS) is examined, both in its wild-type PfTyrRS linked to ML901-Tyr and AMS-Tyr, and with the S234C mutation, again in complex with ML901-Tyr. Using the method of molecular fractionation with conjugated layers (MFCC), amino acid residues were partitioned to calculate individual interactions using the formalism DFT (Functional Density Theory). The study with PfDHODH enzyme revealed that amino acid residues Arg265, Cys184 and Phe188 were crucial for the interactions and exhibited significant interaction energies with the four complexes studied. Moreover, the energy value of the DSM1 inhibitor was not affected by the structural changes caused by the C276F mutation, demonstrating its ability to bind to the enzyme. Working with PfTyrRS, six important residues were found to be common to the three complexes. These residues include Asp61, Gln73, Gln192, Gln210, Met237, and Phe63, most of which play essential roles in ATP binding. This discovery provides a comprehensive understanding of the interaction between PfDHODH and PfTyrRS enzymes and their inhibitors. The information gathered in this study is proving to be relevant to the development of new drug therapies and could become a tool in exploring the design of new, more sophisticated and effective antimalarial drugs.

The emergence of microorganisms resistant to conventional drugs consti-tutesaseriousglobalpublichealthissuethatlimitstherapeuticoptionsand underscores the urgent need for the discovery of new antimicrobialagents.ThevenomofthescorpionTityusstigmurusservesasarichsource of biologically active components, including antimicrobial peptideswith high therapeutic potential. Stigmurin, an antimicrobial peptide withantibiotic activity against Gram-positive bacterial strains, was used as aprototype for structural modifications, resulting in the generation of 31analogs (patent BR102015029044-6). In this study, the three-dimensionalconformation was elucidated using nuclear magnetic resonance (NMR),stability was investigated through circular dichroism, and the in vitro andin vivo antibacterial action of two analog peptides of Stigmurin, namedStigA25 and StigA31, was assessed. In addition to the remarkable antimi-crobial activity described in a previous study, StigA25 and StigA31 exhib-ited concentration-dependent hemolytic activity compared to the proto-type peptide. To mitigate cytotoxicity, enhance stability, and optimizetherapeutic efficiency of these peptides, the effect of associating thesebioactive components with poly(lactic-co-glycolic acid) (PLGA) nanopar-ticles was investigated. StigA25 and StigA31 displayed a predominant α-helical conformation by NMR, with high structural stability under varioustemperature, pH, and salt conditions as determined by circular dichroism.The incorporation of these components into PLGA nanoparticles resultedinastablenanosystemwithantimicrobialactivityequivalenttothatoffree peptides and a significant reduction in toxicity. Scanning and trans-mission electron microscopy demonstrated that both free and nanoparticulated peptides exerted their action on the bacterial cell membrane, causingmembrane disruption. Therefore, this study reveals the high therapeuticpotential of StigA25 and StigA31 when associated with PLGA nanosystems, suggesting the use of this nanocarrier as a promising tool for thetherapeutic application of these bioactive molecules in the development ofnewanti-infectious agents.

The worldwide increase in urbanization and industrial activities has led to the production and introduction of contaminating molecules into ecosystems. Pollution of water bodies by untreated sewage causes numerous damages to species living in the aquatic environment. Biotechnological processes and physical, chemical, and biological strategies have been developed to remove these contaminants from anthropogenically polluted waters. From the perspective of bioremediation, lacases are enzymes capable of degrading phenolic, aromatic, and non-aromatic compounds, including synthetic dyes from the textile industry. In this context, the present work proposes to analyze the intermolecular contacts of Congo red dye coupled to lacases from Tratametes versicolor (CR -LacTv) and Pycnoporus sanguineus (CR -LacPs) qualitatively (type of chemical bonding), quantitatively (interaction energy), and comparatively, including the identification of interaction patterns. To describe the individual ligand-receptor type binding energies present in these biocomplexes, we used the molecular fractionation scheme with conjugated caps (MFCC) in the framework of density functional theory (DFT). The results indicate a higher affinity of the Congo red dye for the lacase of Pycnoporus sanguineus. In this case, the dye interacts with LacPs (LacTv) with a binding energy of -38.26 kcal/mol (-19.26 kcal/mol), with 63.3% (63.6%) of the intermolecular contacts occurring with the amino acids of the receptor from the iii (i) region of this ligand. The major residues of the CR -LacPs (CR -LacTv) complex are ARG161, PHE162, GLY392, GNL160, SER393, PRO391, PHE265, and GLY266 (PHE162, ALA161, GLY266, ALA393, PHE 265, PRO391, PRO160, GLY392), in which we highlight the existence of six (five) large hydrogen bonds and two (three) hydrophobic contacts in CR -LACPs (LacTv). The structural and energetic description of the interactions of the biocomplexes in question helps to understand the differences in terms of stability and efficacy of enzymes of the same family but different organisms. Consequently, it will allow studies to increase the effectiveness of bioremediation promoted by such enzymes following targeted point changes.

Aedes aegypti (L., 1762) and Aedes albopictus (S., 1894) are vectors of the etiological agents of numerous arboviruses of medical importance. Limitations in the use of chemical insecticides have stimulated the search for effective and ecologically friendly options, such as botanical insecticides. The present study describes the aedicidal potential of Anadenanthera colubrina (Vell.) seed extract at different stages of the vectors' life cycle, its attractive/repellent action on oviposition, partial biochemical characterization and evaluation of cyto- and ecotoxicity. The hot aqueous extract of A. colubrina seeds (EAQA) was obtained by extraction in distilled water (1:10, m/v) for 7 h at 80 °C. The larvicidal effects of EAQA were evaluated in serial dilutions and the lethal LC50 and LC90 concentrations (mg/mL) determined after 24 h and 48 h of exposure. The larvicidal effect was observed for A. aegypti and A. albopictus, recording LC50 and LC90 at 24 h (0.16 and 0.94 mg/mL; 0.36 and 1.28 mg/mL) and 48 h (0. 02 and 0.26 mg/mL; 0.06 and 0.62 mg/mL), respectively. EAQA was pupicid for both insects at concentrations higher than larvicidal concentrations (24 h LC50 ≥ 0.85 mg/mL and 48 h LC50 ≥ 0.53 mg/mL). 0.26 mg/mL was defined as the diagnostic concentration for ovicidal activity and oviposition, showing ovicidal activity for both insects, compromising larval hatching by 76% and reducing adult emergence of surviving larvae by 25%. Under field conditions, EAQA exerts an attractive effect on oviposition. EAQA showed a higher concentration of total carbohydrates (15.5 mg/mL) compared to total soluble protein (2.0 mg/mL) and total phenolic compounds (0.1 mg/mL). EAQA presents bromelain, papain, trypsin and chymotrypsin inhibitors, with enzyme inhibition activity in 90.94%, 68.93%, 68.75% and 9.32%, respectively. No cytotoxicity was observed for tested cell lines (3T3) and (HepG2), nor ecotoxicity for Ceriodaphnia dubia (LC50 = 0.72 mg/mL for 24 h and 0.34 mg/mL for 48 h) and Mysidopsis juniae (LC50 = 0 .87 mg/mL for 24 h and 0.37 mg/mL for 48 h). EAQA has the potential to be an adjuvant in Aedes integrated management strategies due to the versatility of action against different stages of the vectors' life cycle, as well as their cyto- and eco-compatibility.

In recent decades, the increase in bacterial resistance to conventional treatments has led to an incessant search for new effective alternatives against diseases caused by these microorganisms. Within this context, significant progress has been achieved in the development of drugs based on nanotechnology in order to combat/attenuate bacterial resistance. And among the nanoparticles, those made of silver (NANO) are pointed out as a promising option in this sense, including being already applied in different uses, such as in the textile industry. However, their use in clinical medicine has a smaller dimension, and this has been driving the development of different mixed NANO, which contain, in addition to silver, an organic portion in their constitution, since this can enhance or provide new applicability to NANO. This has even allowed the use of techniques less aggressive to the environment (green synthesis) for the synthesis of NANO. Polysaccharides are one of the organic molecules that have been used in this sense. Xylan is a hemi-cellulose found in different plants and, therefore, very abundant in nature. However, there are less than a dozen papers with NANO containing xylans, and none have evaluated their antimicrobial effect. Therefore, in this work NANO was synthesized with different xylans extracted from corn cob (Zea mays). For this, corn cob, in 0.1M NaOH, was subjected to ultrasound waves to obtain a xylan-rich extract (EBX), which was subsequently fractionated with the addition of increasing volumes of ethanol. Thus, six ethanolic fractions (EF's) were obtained, which after being characterized (sugar content, proteins, phenolic compounds, and monosaccharide composition), were used for the green synthesis of NANO. These NANO were characterized by UV-visible spectroscopy, scanning electron microscopy, dynamic light scattering, energy scattering spectroscopy and infrared spectroscopy. All NANO (NANO EBX, NANO E0.3, NANO E0.4, NANO E0.8, NANO E1.4 and NANO E2.2) were essentially composed of silver and xylans, presented round shape, average size ranging from 105, 0 and 79.7 nm and stability of 24 months. These NANO were not cytotoxic against fibroblast (3T3) and macrophages (RAW). Furthermore, they promoted the reduction of nitric oxide (NO) production in macrophages activated by bacterial lipopolysaccharide. The different NANOs, synthesized here, also showed antibacterial activity. All were effective against Gram-negative bacteria tested (Escherichia coli; carbapenemase-producing Klebsiella pneumoniae – KPPC) with emphasis on NANO EBX and NANO E1.4, which showed a minimum inhibitory concentration (MIC) of 62.5 µg/mL against E. coli. For KPPC, NANO EBX, NANO E0.4, NANO E1.4 and NANO E2.2 stand out, which presented a MIC of 250 µg/mL. The data presented here show the biotechnological potential of the different xylans in the form of nanoparticles and future tests, including in vivo, should be carried out to confirm the antibacterial potential of the different NANO synthesized with EBX and FE's.

In the face of the reality of teaching biochemistry, which is permeated by the densification of the contents, the interdisciplinary complexity, and aggravated by an exclusive or excessively expository approach, it becomes increasingly necessary to evaluate methodological proposals that mitigate this scenario. Thus, in this dissertation, we developed a work proposal for a Blended Learning Gamified, based on the Flipped Classroom, in the Biochemistry classes; academic performance assessment; the interest and involvement of students in the subject; the methodological elements of the proposal, gamification, and, finally, gains in cognitive, social and socio-emotional skills. Therefore, a type of exploratory research was carried out, through a pedagogical intervention with qualitative and qualitative analysis. The proposal was applied in two biochemistry disciplines at the Federal University of Rio Grande do Norte (UFRN) for the biological sciences, in the periods of 2016.2 and 2017.1, and in medicine courses, in the periods of 2018 and 2019, a total of 179 students participated in this study. The research analyzed data from the design of two classes: face-to-face and blended classes, which were divided into online moments and in-person moments, with educational objectives combined in both moments. For the online moments, were used video lessons and the face-to-face moments, educational objects elaborated by Bloom's Taxonomy were applied. The entire process was gamified, with a scoring system (ranking), team building in the cooperative logic and obtaining benefits (reward system). The entire process was gamified, with a scoring system (ranking), team building in the cooperative logic and obtaining benefits (reward system). The results show that most students had better academic performance, and reported increased interest in the discipline, stating that learning was better in blended classes than in face-to-face classes. Furthermore, gamification had a positive evaluation and ended up promoting increased student engagement. Besides, it was shown that the method contributed to collaborative and personalization learning. Finally, it was observed that the pedagogical intervention contributed to the development of specific aspects for the discipline of biochemistry, for example, the understanding of concepts, relationships between structures and functions, and proposing solutions and arguments for solving problems, among others. After all, the results described here provide data for a discussion about the importance of Blended Learning Gamified as a promising alternative to the disciplines of biochemistry. Certainly, this requires a broad reflection on the approaches and processes involved in this model, because studies on the effectiveness of Hybrid Teaching for the Teaching of Biochemistry are still very scarce.

Ophidism causes high mortality and morbidity in many regions of the world. Currently, the only treatment is serum therapy, which has some limitations, such as: high cost for its production, low effectiveness in neutralizing local effects, difficult access in some regions and adverse reactions. Considering these factors, this study has the general objective of presenting new alternatives to improve the treatment of snakebite. For this purpose, the venom of the Bothrops brazili snake was used, a little studied species that is found mainly in the Amazon region. Thus, the present study has as specific objectives (1) to analyze the inhibitory potential of chlorogenic and rosmarinic acids against the local and systemic effects induced by B. brazili envenomation, (2) to obtain and characterize chitosan nanoparticles with the venom of this species with two modes of association (incorporation and adsorption), in order to be evaluated in relation to the immunoadjuvant potential for the production of a new serum. The evaluation of the antiophidic potential of chlorogenic and rosmarinic acids was carried out through in vitro, in vivo and in silico assays. In vitro, the acids were able to inhibit proteases and phospholipases activities of the venom, in addition to reducing the pro-coagulant effect in human plasma caused by the venom. In vivo, in a mouse model, these compounds inhibited local effects such as edema, hemorrhage, increased myeloperoxidase enzyme and myotoxicity. In silico the acids were able to interact with venom phospholipases. In addition, the compounds mitigated the systemic effects resulting from the envenomation, which were: kidney, liver, muscle damage, hemostatic changes (partially activated thromboplastin time, prothrombin time and platelet count), hematological (erythrogram and leukogram) and lipid peroxidation. For the production of chitosan nanoparticles, the ionic gelation technique was used. The nanoparticles had a size between 150 and 190 nm, a potential of approximately +30 mV and a polydispersity index (PDI) of approximately 0.400. These parameters were evaluated by the Dynamic Light Scattering (DLS) technique. The nanoparticles showed 97% efficiency to incorporate and adsorb the venom and the analysis of scanning electron microscopy with field emission source (MEVFEG) and atomic force microscopy (MFA) showed that they had homogeneous shape and size. Fourier transform infrared spectroscopy (FTIR) analysis revealed that the venom showed bands at 1543 cm-1 and 1651 cm-1 referring to amide groups. The nanoparticles showed bands at 916, 1087, 1259 and 1340 cm-1 that underwent deviation after incorporation and adsorption of the venom. In conclusion, these results demonstrate that chlorogenic and rosmarinic acids have the potential to inhibit the local and systemic effects caused by B. brazili envenomation, which makes them possible alternatives to complement serum therapy. Furthermore, chitosan nanoparticles were efficient in incorporating and adsorbing the venom, showing great potential to be used as an adjuvant in the production of a new antivenom.

Snakebites represent a serious public health problem in tropical countries. Bothrops leucurus snake is one of the main responsible for snakebites in Northeast Brazil, but this species is not included in the pool used in the production of antiophidic serum. Considering the limitations of the antiophidic serum, several studies have been carried out in order to develop complementary treatments for snakebite and, in this context, plants are an important source of bioactive compounds. Chlorogenic acid and rosmarinic acid are molecules derived from the secondary metabolism of plants, with several biological activities described and antiophidic potential still little explored. Thus, the aim of the study was to evaluate the inhibitory potential of chlorogenic and rosmarinic acids against the effects of B. leucurus venom. Initially, in vitro neutralization capacity of the enzymatic activities of the venom was evaluated. Then, in vivo tests were performed to verify the inhibition of acids against hemorrhagic, edematogenic, myotoxic activities and quantification of inflammatory markers, as well as the analysis of biochemical, hemostatic, hematological markers, and verification of the degree of lipid peroxidation in renal and liver tissues. Finally, the ability of the inhibitors to interact in silico with two classes of toxins was evaluated. The results showed that chlorogenic and rosmarinic acids were effective in inhibiting phospholipase A₂ (21% and 60%), proteolytic (39% and 60%), hyaluronidase (59% and 75%) and coagulant (p < 0.0001) activities, respectively, as well as were effective in preventing fibrinogen degradation. In in vivo assays, the inhibitors attenuated edema (p < 0.01), reducing the levels of myeloperoxidase (p < 0.001), IL-6 (p < 0.0001) and IL-1β (p < 0.001) interleukins. The compounds also inhibited the hemorrhagic (p < 0.0001) and myotoxic (p < 0.001 – chlorogenic acid, p < 0.0001 – rosmarinic acid) actions of the venom. In serum biochemical markers, the inhibitors attenuated changes in urea levels (p < 0.01 - chlorogenic acid and p < 0.05 - rosmarinic acid), creatinine (p < 0.0001), uric acid (p < 0.0001 ), alanine aminotransferase (p < 0.05), aspartate aminotransferase (p < 0.001- chlorogenic acid and p < 0.05 - rosmarinic acid), amylase (p < 0.01), total proteins (p < 0.01), creatine kinase (p < 0.01) and lactate dehydrogenase (p < 0.0001). Furthermore, both compounds decreased the levels of lipid peroxidation in liver (p < 0.001) and renal (p < 0.0001) tissues. When evaluating hemostatic parameters, only rosmarinic acid was able to reduce the effects on circulating fibrinogen (p < 0.0001) and platelet count (p < 0.0001). Computational studies indicated that the inhibitors have the ability to interact with toxins of the phospholipase A₂ and metalloprotease class. Taken together, the results obtained evidenced the antiophidic potential of chlorogenic and rosmarinic acids, which presented, in general, greater inhibition efficiency than the antiophidic serum. Thus, both inhibitors are promising candidates for the development of future adjuvants to be used to complement the currently available antivenom sorotherapy.

Carotenoids act by reducing oxidative stress and, therefore, act on the inflammatory process. Encapsulation can preserve and/or enhance the functional properties of these natural pigments, such as antioxidant activity. In the present study, divided into chapters, we sought to evaluate how encapsulation acted to improve the antioxidant and anti-inflammatory activity of carotenoids. The first and second chapters, referring to the systematic review (SR), are organized as follows: the first presents the SR protocol with an international prospective registry of systematic reviews (PROSPERO, under number CRD42020142065); and the second, RS, which brought together and systematized studies in vitro, ex vivo, in vivo, which evaluated the effect of different carotenoid encapsulation techniques on antioxidant activity. The articles were selected according to the PICOS strategy (population, interventions, control, results and type of study) and searches were performed in PubMed, Embase, Virtual Health Library, Scopus, ScienceDirect and Web of Science databases. The methodological quality assessment was performed using the OHAT (Office of Health Assessment and Translation) tool. A total of 1577 articles were selected, resulting in 20 eligible studies. The results showed that encapsulation promoted changes in the chemical structure of carotenoids and the emergence of new chemical interactions, in addition to increasing the surface area, resulting in the preservation and enhancement of antioxidant activity. The third chapter refers to the experimental study, which evaluated the effect of the crude extract rich in carotenoids obtained from the Cantaloupe melon (Cucumis melo L. var cantalupensis) (EB) nanoencapsulated (EGS) in Wistar rats with inflammation induced by the consumption of high glycemic index and high glycemic load (HGLI) diet on systemic and adipose tissue inflammatory response. The EB was characterized by spectrophotometric and chromatographic methods, and the EGS was characterized by physical and chemical methods, as well as the evaluation of the incorporation efficiency. The in vivo experiment was carried out for 11 days with male Wistar rats (n = 20) with diet-induced inflammation, subdivided into four groups: no treatment (HGLI diet + water), conventional treatment (HGLI diet + nutritionally adequate diet), test 1 [HGLI and EB diet (12.5 mg/kg)] and test treatment 2 [HGLI and EGS (50 mg/kg)]. The groups were investigated in relation to food consumption, caloric intake, caloric efficiency and weight. Inflammatory cytokines were measured in plasma (TNF-α, IL-6 and leptin) and in adipose tissue (TNF-α and IL-6). In addition, the weights of visceral adipose tissue (retroperitoneal, epididymal and perirenal) were recorded, histopathological analyzes were performed, and investigation of the antioxidant activity in plasma and visceral adipose tissue through the quantification of malondialdehyde, sulfhydryls and superoxide dismutase (SOD) activity). For the in vivo experiment, no changes were observed in food consumption, intake, caloric efficiency and weight (p > 0.05). However, the animals treated with EGS had a lower mean variation in dietary intake and were the only group that showed only weight loss. This group also showed improvement (p < 0.05) in plasma concentrations of inflammatory cytokines (IL-6 and leptin), however, there was no difference in the dosage in adipose tissue. In visceral adipose tissue, it was found that the largest focal area of multilocular adipocytes was observed for the EGS-treated group. In addition, EGS may be acting in a mimetic way to SOD and, therefore, reducing oxidative stress. Thus, the present study presents a relevant scientific contribution, as RS generated information regarding the effect of nanoencapsulation on antioxidant activity and, in the pre-clinical study, on inflammation.

Antimicrobial peptides are molecules considered one of the first defense lines against microorganisms. From the transcriptome of a scorpion venom gland, our research group identified the antimicrobial peptide Stigmurin, from which amino acid residues were changed and two analog peptides denominated StigA6 and StigA16 were designed and studied. These peptides presented in vitro activity against Gram-positive and Gram-negative bacteria higher than the native peptide. To deepen the knowledge on these peptides here we studied their antibacterial activity against multidrug-resistant bacteria in vitro and in vivo assays of larval infection and mice polymicrobial sepsis. The structures of these peptides were evaluated when interacting with lipid vesicles by circular dichroism and by liquid-state nuclear magnetic resonance (NMR). Regarding their in vitro antibacterial activity, StigA6 and StigA16 showed high activity against multidrug-resistant S. aureus and P. aeruginosa, and antibiofilm effect on multidrug-resistant S. aureus. Both peptides were able to control infections in Galleria mellonella larvae, increasing survival and reducing colony-forming units, hemocytes and melanization. In mice polymicrobial sepsis, the analog peptides were able to reduce viable microorganisms, leukocytes migration and myeloperoxidase activity. As for their interaction with lipid vesicles both peptides showed higher interaction with bacterial membrane-mimetic vesicles than with eukaryotic membrane-mimetic vesicles. NMR data showed that both analog peptides presented high amphipathicity and longer helical structure than the native peptide, Stigmurin, suggesting that lysine placement is important to helix determination. Therefore, these peptides are interesting targets in the study of new anti-infective molecules.

Inflammatory bowel diseases (IBD) are chronic inflammatory pathologies associated with genetic alterations and environmental factors. The drugs available for treatment can cause potentially serious adverse effects, showing the need to search for new therapeutic strategies. Foods rich in bioactive compounds with anti-inflammatory activity stand out, such as Cereus jamacaru P. DC. This research aimed to chemically characterize and evaluate the anti-inflammatory effect of the Lyophilized Hydroethanolic Extract of Cereus jamacaru P.DC. in an experimental model of inflammatory bowel disease induced by 2,4-dinitrobenzene sulfonic acid (DNBS). The mandacaru cladodes were collected in the city of Jucurutu/RN, the thorns were removed, cut and dried, then they were ground, going through maceration with ethanol and water, obtaining the Lyophilized Hydroethanolic Extract of Cereus jamacaru (EHCJ). The phytochemical prospection of EHCJ was carried out by liquid chromatography coupled to a mass spectrometer to assess the presence of phenolic compounds. In the study of the intestinal anti-inflammatory activity were used Rattus norvegicus (Wistar), adult females (n = 8/group), weight 230 ± 20 g, randomly distributed in the groups: normal control, DNBS collitic control, sulfasalazine 250 mg/Kg and EHCJ (50, 100 and 200 mg/kg/day). Intestinal, macroscopic and microscopic clinical parameters, volatile compounds and fatty acids present in feces, inflammatory markers such as myeloperoxidase enzyme (MPO) dosage, gene expression were evaluated mitogen activated protein kinase (MAPK) and metalloproteinase 9 (MMP-9), expression of the kappa beta factor gene and protein (NF-κB p65); cytokine dosages (TNF-α, IL-10 and IL-1β; evaluation of oxidative stress by measuring malondialdehyde (MDA) and reduced glutathione (GSH); integrity of the intestinal barrier through the expression of the occludin gene (OCL) and expression of the mucin 2 (MUC-2) and occlusion zone (ZO-1) proteins. The results of the phytochemical analysis identified the compounds derived from benzoic acid, saccharide, Kampferol-3-O-dirhamnosyl-hexoside, Isorhamnetin-3-O-dirhamnosyl-glucoside, Kaempferol-3-O-rutinoside, Isorhamnetin-3-O-rutinoside and oxo-dihydroxy-octadecenoic acid. The GC-MS of feces identified 18 compounds, which were fatty acids, hydrocarbons, sterols and phenol according to the fragmentation patterns. In the colitis model, pretreatment with EHCJ at doses of 50, 100 and 200 mg/kg was able to cause chemoprevention observed through the Disease Activity Index (IAD) (p < 0.05). Furthermore, it reduced the colonic damage induced by DNBS with a reduction in the macroscopic damage score (p<0.05). The treatment reduced MPO enzyme activity (p<0.05) and colonic MDA levels (p<0.01) and increased GSH levels (p<0.05) for all doses tested. The extract also reduced tissue levels of the cytokines TNF-α (p<0.0001) and IL-1β (p<0.05) and increased IL-10 at a dose of 200 mg/Kg (p<0.01 ). The preventive effect was also demonstrated by the increased expression of the OCL gene, involved in the integrity of the intestinal barrier and decreased expression of the markers of the MAPK (p<0.01) and NF-κB p65 (p<0.0001) pathways. Histopathological analyzes show that EHCJ significantly reduced the infiltrate density (p<0.001) and immunohistochemistry exhibited increased immunoreactivity for MUC-2 (p<0.01) and ZO-1 (p<0.05) and a reduction of this immunostaining for NF-κB proteins p65 (p<0.05) and MMP-9 (p<0.05). Thus, preclinical results indicate that EHCJ is a product rich in bioactive compounds, beneficial in the chemoprevention of colitis, and may, in the future, become an alternative in the treatment of human IBD.

Refined sugar (sucrose) is very versatile and cheap and can be found in many recipes. A diet high in sugar can have negative consequences, such as obesity and diabetes, and its withdrawal can promote behavioral changes, such as binge eating. The aim of this research was to test the hypothesis that sucrose withdrawal favors depression-related behaviors. For this purpose, 30-day Wistar rats from the vivarium of the Centro de Biosciences-UFRN were used, receiving water and feed ad libitum and were submitted to the paradigm of choosing two bottles with 250 ml of water and/or 5% sucrose (group sucrose) for 16 days, followed by its withdrawal from 72h to 96h (short-term withdrawal group) or 22 to 23 days (long-term withdrawal group). Animals in the control group, sucrose, short-term withdrawal and long-term withdrawal were submitted to the open field test 72h and 22 days after the replacement of sucrose by water for the short-term and long-term withdrawal groups, respectively. Twenty-four hours after the open field test, all groups were submitted to the forced swim test. The data obtained here showed no behavioral effects of exposure or withdrawal in the short and long term of sucrose in the forced swimming test, as well as no statistical differences in the results of the locomotion parameter in the open field test. Thus, we conclude that short- and long-term exposure and withdrawal of sucrose were not able to generate depressive-like behavior in adolescent rats.

Flowering is a critical stage that promotes the transition of shoot apical meristem from the vegetative to reproductive stage. This transition is orchestrated by different signal (external and internal) that have been characterized in different models as Arabidopsis thaliana, Oryza sativa and Zea mays. For sugarcane this process is not well-known in molecular way. However, it has an important impact in yield and production. Considering this, the work present here has the aim to characterize a sequence that had homology to HINT1 protein by different approaches. This sequence was previously identified using subtractive libraries from shoot apical meristem during different stages of sugarcane development. It was verified that HINT sequences were conserved in plants, and it was separate into two large branches: monocotyledons and dicots. The data obtained from the 3D modeling showed that ScHINT may be a functional protein, as it presents the important binding sites for its catalytic activity. A second protein that was worked was ScSUBTILASE. This protein was characterized had been previously identified in a protein-protein assay using the two-hybrid methods. Here, it was attempted to understand the role of SUBTILASE and HINT1. It was verified that the ScSUBTILASE protein was also conserved in plants, and the modeling showed that it might also be functional due to the 3D structure and the presence of catalytic sites. In the two-hybrid assays, a third protein was identified with homology to PHENYLALANINE AMMONIA-LYASE. The modeling was carried out and it was observed that this too must be functional. The other approached used was interactome using STRING. The results obtained for the proteins HINT, SUBTILASE and PHENYLALANINE AMMONIA-LYASE in the Arabidopsis model showed that these sequences are associated with the response of the production of ROS. Based on the results presented and on the literature data, it may be proposed that ScHINT and ScSUBTILASE may have the role of maintaining the level of ROS at the shoot apical meristematic during the transition process. The results obtained with transgenic Nicotiana tabacum plants containing over-expression cassettes in sense and antisense orientations for ScHINT1 reinforce the proposal idea that ScHINT may be associated with the flowering process.

Subclinical inflammation in overweight and obesity alters several metabolic pathways, with positive reinforcement for the accumulation of more adipose tissue and alterations in energy metabolism. Several studies have evaluated the anti-inflammatory and immunomodulatory effects of hydrolyzed proteins and plant peptides. However, it is still necessary to explore the mechanisms of action. Thus, in the first chapter of this thesis, a narrative review is presented, aiming at understanding the mechanisms of action of proteins and peptides on inflammation, present in the accumulation of adipose tissue. Thus, a search was carried out in databases, selecting studies that involved target metabolic pathways and responses of proteins or peptides, which favored the reduction of inflammatory cytokines and adipokines, as well as the polarization of macrophages to the M2 phenotype. In the second chapter, the in vitro and computer simulation studies (in silico) study with the purified trypsin inhibitor from tamarind seeds (pTTI) is presented. This protein has been studied in vitro and preclinical studies for the treatment of obesity, its complications, and associated comorbidities. The pTTI was sequenced again by MALDI-TOF/TOF, its homology modeling was obtained, and the interaction with the trypsin enzyme was evaluated through molecular dynamics (MD) simulation under physiological conditions. A further 75 amino acid residues have been identified. Homology modeling was performed by CONCOORD and validated by MolProbity and the four best conformations of the modeling were submitted to DM. Conformation No. 287 of model No. 56 was selected, considering the RMSD analysis and the interaction energy (-301.0128 kcal.mol-1). Residues Ile (54), Pro (57), Arg (59), Arg (63) and Glu (78) of the pTTI presented lower interaction energy, which reflects the residues with greater interaction with the enzyme trypsin and the residues of Arg are mainly involved in its electrostatic binding mechanism. Once aware of potential molecular targets of plant peptides for the treatment of obesity revealed through the narrative review, in addition to the structure and function of the pTTI through the in vitro and in vivo study, this in silico study demonstrated optimization of bioprospecting of pTTI through bioinformatics. Finally, the results found and the paths addressed favor the continuity of studies of this protein for applications in pre-clinical and clinical studies in the health area, aiming to contribute to the control of obesity, a serious public health problem.

During  the  extractive  processes  of  oil  and  gas,  production  water  is  also  formed,  which  is composed  of  or ery). ganic  and  inorganic  matter,  in  addition  to  microorganisms.  The  microbiota  of this  environment,  adapted  to  extreme  conditions,  has  great  potential  for  application  in biotechnological  processes,  such  as  bioremediation  and/or  MEOR  (Microbial  Enhance  Oil Recov Within  this  context,  this  study  aimed  at  the  isolation,  identification  and characterization  of  bacteria  from  three  consortia,  previously  obtained  from  production  water. A  total  of  16  bacteria  were  isolated,  fifteen  of  them  selected  for  metabolic  char acterization from  functional  assays.  Isolates  were  selected  according  to  their  ability  to  use  hydrocarbons as  a  carbon  source.  Considering  the  evaluation  of  hydrocarbon  degradation,  the  test  with redox  indicator  2,6 DCPIP  (2,6Dichlorophenolindophenol)  w as  used  and  tests  such  as Emulsification  Index,  drop  collapse  and  oil  dispersion  were  applied  to  evaluate  the production  of  biosurfactants  /  bioemulsifiers.  The  results  obtained  from  the  degradation  tests confirmed  the  capacity  of  fifteen  isolates  to  use  p etroleum  and  other  hydrocarbons  as  the only  source  of  carbon. The  tests  carried  out  for  the  production  of  biosurfactants  confirmed the  capacity  of  15,  among  the  sixteen  isolates,  to  produce  biosurfactants  and/or  to  form  an emulsion.  Based  on  the  16S  gene  sequence,  the  isolates  were  identified  as Bacillus, Acinetobact er,  Staphylococcus,  Ochrobactrum and Citrobacter . Among  the  isolates,  four were  selected  and  had  their  genomes  sequenced,  being  identified  as Ochrobactrum (1)  and Acinetobacter  baumanii Bacillus  safensis (1).  Isolate  AP1BH01(2), 1,  classified  as  a member of  the  genus Ochrobactrum ,  was  designated  as  a  new  species,  since  it  does  not  group with  another  species  of  the  genus.  The  genomes  of  the  sequenced  isolates  showed  a  great diversity  of  genes  involved  in  the  degradation  of  aliphatic  and  aromatic  hydrocarbon s,  as well  as genes  for  the synthesis  of biosurfactants  and bioemulsifiers. Several  genes related  to resistance  to  heavy  metals  have  also  been  identified.  The  data  obtained  through  functional assays  and  genome  mining  of  the  isolates  revealed  promising  prof iles  in  hydrocarbon degradation  processes  and  production  of  biosurfactants  for  application  in  bioremediation  of environments contaminated with hydrocarbons and/or MEOR.

          A busca pela manutenção da integridade genômica é uma tarefa constante nas células de todos os organismos vivos. DNA polimerases replicativas atuam de forma rápida e fiel durante a replicação para que a cópia da informação genética passada de uma geração a outra seja fidedigna. Além disso, devido ao genoma ser constantemente agredido por agentes endógenos e exógenos capazes de lesionar a molécula de DNA, são acionados na célula sistemas de reparo de DNA capazes de prevenir os efeitos prejudiciais dessas lesões, uma vez que elas podem levar à mutações. Embora esses mecanismos sejam eficientes na restauração da molécula de DNA, muitas lesões escapam da correção e acabam sendo encontradas pela polimerase replicativa – enzima nem sempre capaz de sintetizar moldes de DNA danificados. Dependendo do tipo de lesão, esse encontro pode resultar no colapso da forquilha de replicação e, consequentemente, mecanismos capazes de burlar esses obstáculos são acionados. Uma das alternativas é a utilização de polimerases de síntese translesão especializadas capazes de replicar as lesões mesmo com o custo da mutagênese, em um processo chamado de Síntese Translesão. Dentre os mais diversos agentes danosos ao DNA está o poluente Benzo[a]pireno, um potente carcinógeno onipresente no ambiente. Esse químico, ao ser metabolicamente ativado na célula, gera os subprodutos BaP+ e BaP- que se ligam como adutos ao DNA de forma covalente, sendo potentes bloqueadores da forquilha de replicação. Nesse trabalho são apresentados alguns dos requerimentos para a ocorrência em E. coli da síntese translesão desses adutos estereoisômeros BaP+ e BaP-, inseridos no contexto de sequência CTG^BaP+/-CAG. Os resultados mostram que enquanto o principal aduto BaP+ requer as duas enzimas de síntese translesão cataliticamente ativas Pol IV e Pol V para ser replicado, BaP- exige apenas Pol IV. Dados demonstram que a taxa de síntese translesão desses adutos possui relação positiva com a concentração de polimerases especializadas no meio celular, as quais possuem níveis aumentados pela indução da resposta SOS. Além disso, é sugerido um desbalanço do pool de nucleotídeos que desloca a reação de síntese translesão no sentido da síntese e um modelo de replicação desses adutos.