Banca de QUALIFICAÇÃO: JÚLIA FIRME FREITAS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : JÚLIA FIRME FREITAS
DATA : 12/03/2019
HORA: 14:00
LOCAL: Sala Carl Peter von Dietrich - Departamento de Bioquímica
TÍTULO:

Characterization of the microbiota obtained from a pre-salt sample.

PALAVRAS-CHAVES:

Consortium. Metagenomics. Petroleum. Microorganisms. Biodegradation.

PÁGINAS: 88
GRANDE ÁREA: Ciências Biológicas
ÁREA: Bioquímica
RESUMO:

The biodegradation of oil is a worldwide problem because the action of the microorganisms causes a reduction in the quality of the oil. The identification of the microbiota that contribute to the reduction of oil hydrocarbons presents a vast biotechnological potential, for example, to provide information for the restriction of biodegradation, application in bioremediation processes or advanced oil recovery. The objective of this work is to obtain and characterize consortia and microbial isolates capable of degrading petroleum. There were 3 non-defined consortia of a pre-salt sample, plus 17 bacteria isolated from the consortia and 9 strains from the petroleum sample. The tests were carried out for the consortia and the isolated microbiota: i) oil degradation with the redox indicator test 2,6-Dichlorophenolindophenol (DCPIP) using 9 sources of hydrocarbons (petroleum, soybean oil, olive oil, gasoline, diesel, kerosene, hexadecane, toluene and xylene) and glucose as a positive control; ii) production of biosurfactants; iii) cellular hydrophobicity; iv) biofilm production; v) enzymatic activity of hydroxylases; vi) presence of rhamnolipid; vii) growth curve; viii) gene analysis by the molecular panel. The isolates were identified as belonging to the genus Bacillus (n = 8), species B. megaterium (n = 1), Family Brucellaceae (n = 10) and Bacterium culalenE36 (n = 1). All the isolates had the capacity to degrade petroleum and some products by the DCPIP test; only 46 % of them used kerosene and 7 % xylene and toluene as carbon sources. All isolates produce Biosurfactant by the dispersion assay, and emulsification occurred in 84 % of the microorganisms. Lipase was produced by all isolates, however only 4 lines produced esterase. There was a positive correlation between biofilm production and cell hydrophobicity and negative for emulsification index with hydrophobicity and biofilm. Eleven isolates were selected for the construction of the consortium, whose results presented functional characteristics (growth curve, hydrocarbon degradation and biosurfactant production) similar to the non-defined consortia also obtained in this study. The results of the estimation of the degradation of the four consortia indicate that oil, diesel, gasoline, soybean oil, olive oil and hexadecane were completely degraded and for xylene, toluene and kerosene the estimate was >40 %. As well, the emulsion is produced >40 % from the 2nd day of inoculation, peaking at the 16th day,> 58%. The analysis of the molecular panel results showed that the consortia and the isolates present genes involved in the production process of different biosurfactants and methane metabolism. Concluding that the construction of the consortium with selected microorganisms presented results similar to the non defined consortia, indicating a functional redundancy.

MEMBROS DA BANCA:
Presidente - 1997012 - RAQUEL CORDEIRO THEODORO
Interno - 1507794 - RODRIGO JULIANI SIQUEIRA DALMOLIN
Interna - 1199127 - SILVIA REGINA BATISTUZZO DE MEDEIROS