Banca de DEFESA: WYDEMBERG JOSÉ DE ARAÚJO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : WYDEMBERG JOSÉ DE ARAÚJO
DATE: 12/05/2021
TIME: 08:00
LOCAL: Videoconferência - Link para acesso: meet.google.com/aqo-kqpt-cyt
TITLE:

Implications of the Cultivation Medium and the Hydrophobic Substrate in Obtaining Microbial Consortia Producing Biosurfactants and Recalcitrant Hydrocarbones Biodegraders

KEY WORDS:

Biodegradation. Biotechnology. Petrochemical waste. Consortia. Metagenomics. Production water. Biosurfactant

PAGES: 86
BIG AREA: Ciências Biológicas
AREA: Bioquímica
SUMMARY:

The residues produced by the petrochemical industry present a high environmental risk and biotechnological approaches offer promising alternatives for the treatment of these residues in a sustainable way. Through the use of the biosurfactants as adjuvants, microorganisms clean up the waste by degrading the hydrocarbons present in the waste. To select microbial consortia from a sample of the drilling waste and production water (AP) from an oil reservoir, it was demonstrated that the use of medium API oil (American Petroleum Institute) as a carbon source promotes enrichment of the microorganisms involved in the degradation of recalcitrant hydrocarbons through the biosynthesis of the biosurfactants. Four consortia were obtained, two from AP, one enriched in Yeast Extract Peptone Dextrose (YPD consortium) and the other using only the Bushnell-Haas mineral medium (BH consortium). Two other consortia from drilling rock enriched in rich medium Luria Bertani (LB), consortia R1 and R2. Sequences of metagenomic DNA showed that, regardless of the methodology, there were losses of diversity in the consortia. The consortia enriched in LB and YPD showed greater alpha diversity than the BH consortium, which is predominantly composed of members of the genus Brevibacillus. The BH consortium was enriched with genes involved in the synthesis of low molecular weight biosurfactants, while the YPD, R1 and R2 consortia show a greater abundance of recalcitrant hydrocarbon degradation genes. The biosurfactants present in the microorganisms of the BH consortium give them a high cellular hydrophobicity and formation of stable emulsions, suggesting that the absorption of hydrocarbons by the microorganisms is mediated by the biosurfactants. In contrast, the YPD, R1 consortia were more efficient in reducing the interfacial tension. Despite these differences between consortia, oil biodegradation analyses performed by gas chromatography showed few significant differences in relation to the degradation rates of aliphatic and polycyclic aromatic hydrocarbons (PAHs). These data suggest that the enrichment of the biosurfactant genes in the BH consortium could promote a more efficient degradation of hydrocarbons, despite their lower taxonomic diversity compared to the consortium enriched in YPD medium. Together, these results showed that cultivation in a minimal medium supplemented with heavy oil was an efficient strategy in the selection of microorganisms that produce biosurfactants and degradation of compounds that are difficult to degrade in impacted areas.

BANKING MEMBERS:
Externa à Instituição - Ana Tereza Ribeiro de Vasconcelos - LNCC
Interno - 1880243 - DANIEL CARLOS FERREIRA LANZA
Presidente - 1149647 - LUCYMARA FASSARELLA AGNEZ LIMA
Externa à Instituição - MARILENE HENNING VAINSTEIN - UFRGS
Interno - 1507794 - RODRIGO JULIANI SIQUEIRA DALMOLIN