Banca de DEFESA: ANDERSON FERNANDES GOMES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : ANDERSON FERNANDES GOMES
DATA : 28/02/2019
HORA: 09:00
LOCAL: auditório do Química III
TÍTULO:

EVALUATION OF THE POTENTIAL OF MICROALGAE Chlamydomonas sp. CULTIVATED IN AN OPEN SYSTEM AS A SOURCE OF HIGH VALUE METABOLITES WITH APPLICATIONS INTEGRATED TO THE BIOFUELS SECTOR, AIMING AT A BIOREFINERY PERSPECTIVE

PALAVRAS-CHAVES:

Microalgae. Cultivation. Stress. Fatty acids. Residual Biomass. Crude Extract.

PÁGINAS: 125
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Química Orgânica
ESPECIALIDADE: Evolução, Sistemática e Ecologia Química
RESUMO:

Nowadays it is relevant that the processing of any large-scale raw material occurs in a biorefinery design, which consists in optimize the use of resources, aiming at maximizing profitability, benefits and minimizing waste generation. Considering this context, microalgae present high biorrefinario potential, since they exhibit numerous constituents with high value. The microalgae, when subjected to nutrient restriction conditions, become susceptable to the accumulation of total lipids and changes in the fatty profile. In this study, the microalgae Chlamydomonas sp. was cultivated in photosynthetic ponds and submitted to the absence of nutrients. Subsequently, the extraction efficiency of the crude hexanic lipid fraction (CHF), using mechanical agitation associated with the ultrasound technique, was evaluated in two different times (2 and 4 hours). In addition, the biomass before the extractive process (BBE), as well as the residual biomasses from the hexane fraction (RBHF2h and RBHF4h) were monitored by SEM and Thermogravimetric Analysis (TG). Crude protein and high heating value (HHV) were estimated as a function of the elemental composition of biomasses RBHF2h and RBHF4h. Crude chloroform fraction (CCF) was obtained from RBHF4h (extraction with chloroform). The CCF and CHF fractions after hydroesterification were characterized by TG, FTIR and GC/MS. Besides, the crude methanolic extract (CEM) was obtained from CTG biomass with ultrasound as cell rupture system and after that the fraction was characterized by GC/MS. It´s worth pointing out that the CEM over the cell viability of murine melanoma tumor cell line B16F10 and normal line of murine fibroblast 3T3 were evaluated as for the reduction capacity of MTT reagent. Moreover, immunosuppressive potential was also analyzed in macrophags RAW 264.7 model concerning its capacity of nitric oxide production (NO). Surface micrographs of the biomass showed greater fragmentation for RBHF4h, as well as a significant reduction in the typical thermal event of lipids (350-470 °C), indicating extraction efficiency and correlation with the significant difference (greater than 300%) of the obtained CHF at different times. The maximum total lipid fraction (CHF + CCF) was approximately 29%, 60% higher than the control group (CTG). Residual biomasses have HHV and crude protein values at about 19 MJ kg^-1 and above 50%, respectively. The TG and FTIR data presume the predominant composition of saponifiable fractions for the CCF extract, unlike the CHF which is composed especially of unsaponifiables. In addition, the TG curve ratified a better conversion rate for CCF (approximately 89%), consistent with the value obtained by GC/MS (about 86%). The fatty profile of the saponifiable fractions of both extracts showed that fatty acids are mostly composed of C16:0 and C18:3 (ω-3 and ω-6). Another important aspect, and that the stress condition induced a percentage increase of C18:3, however, significantly reduced the C18:2 content when compared to CTG. It is worth mentioning that although the esters exhibit a high concentration of polyunsaturated fatty acids, which compromises their application in the production of biodiesel, the fatty profile of microalgae suggests a pharmacological potential for diet or therapy, since some of the main components are reported as bioactive metabolites. While residual biomass could potentially be targeted to aquaculture (nutritional supplementation) in the face of significant protein content, or for direct combustion due to high value HHV. GC/MS data revealed that CEM composition is mostly of squalene (isoprenoid), phytol (acyclic diterpene alcohol) and adipic acid bis(2-ethylhexyl) ester. The cell viability test revealed that the CEM extract promoted an considerable statistically decrease in the capacity of MTT reduction of B16F10 cell line, over 50%, while any effect over the normal cell line was observed, both until 400 µg mL^-1. Besides, the methanolic extract showed notable inhibitory action on NO production by RAW machophages, promoting a reduction to upper 60% in comparison to positive control (LPS). Therefore, it is possible to infer that the polar extract of microalgal biomass presentes substances with inhibitory potential regarding the viability of câncer cells, as well as the production of inflammatory mediator (NO).

MEMBROS DA BANCA:
Presidente - 1805556 - LUCIENE DA SILVA SANTOS
Interno - 350509 - ANTONIO SOUZA DE ARAUJO
Externa ao Programa - 433663 - MARTA COSTA
Externa ao Programa - 1412709 - NEDJA SUELY FERNANDES
Externo à Instituição - LEANDRO SILVA COSTA - IFRN
Externa à Instituição - MARIANA SANTANA SANTOS PEREIRA DA COSTA - IFRN