Banca de DEFESA: JÚLIA FIRME FREITAS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : JÚLIA FIRME FREITAS
DATA : 30/07/2019
HORA: 13:30
LOCAL: Sala SS1 - Departamento de Biologia Celular e Genética
TÍTULO:

Characterization of the microbiota of the pre-salt sample

PALAVRAS-CHAVES:

Consortium. Metagenomics. Petroleum. Microorganisms. Biodegradation.

PÁGINAS: 115
GRANDE ÁREA: Ciências Biológicas
ÁREA: Bioquímica
RESUMO:

Petroleum is one of the world's main source of energy, on Brazil pre-salt reservoir extraction has boosted oil production. However, such activity generates recurrent environmental contaminations, causing global problems. Microorganisms demonstrate the ability to degrade oil, so microbial metabolism can provide an opportunity to bioremediate contaminated environments and assist in reservoir management, contributing to oil quality or oil recovery. Identification of the microbiota in the reservoir provides essential data to understand the metabolism of oil degradation, but currently there are no analysis of the pre-salt microbiota. The objective of this work was to obtain and characterize consortia (indefinite and selected) capable of degrading petroleum. From a pre-salt oil sample three indefinite consortia and 26 isolates were obtained. Tests were conducted for consortia and isolates, such as: (i) oil degradation ability through the redox indicator test 2,6-Dichlorophenolindophenol (DCPIP) using 9 hydrocarbon sources (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 and vii) growth curve. All isolates demonstrated the ability to degrade petroleum and some by-products by the DCPIP test, however only 46% used kerosene and 7% degraded xylene and toluene as carbon sources. The oil dispersion test showed that all isolates produce biosurfactants, yet only 84% of the bacteria possess the ability to emulsify kerosene. Lipase was produced by all isolates, however, only 4 strains produced esterase. The isolates were identified as belonging to the genera Bacillus (n= 9), Ochrobactrum (n = 11), Acinetobacter (n=2), Dermacoccus (n=1) e Staphylococcus (n = 2). The selected consortium was elaborated with eleven isolates that presented the best results in the functional tests. The estimation of degradation indicate that all consortia degraded 100% of oil, diesel, gasoline, soybean oil, olive oil and hexadecane, while degradation of kerosene, xylene and toluene was above 40%; and the emulsification index of the consortia was above 58%. The comparison of the results between the selected and the indefinite consortia shows similarities in the functional characteristics (growth curve, hydrocarbon degradation and biosurfactant production). It is concluded that the selected consortium presents the same potential of the native microbiota, being a good possibility for application of bioremediation; while indefinite consortia can provide data for reservoir management.

MEMBROS DA BANCA:
Externa à Instituição - ANA LÚCIA FIGUEIREDO PORTO - UFRPE
Interna - 1837354 - JULLIANE TAMARA ARAUJO DE MELO CAMPOS
Presidente - 1149647 - LUCYMARA FASSARELLA AGNEZ LIMA
Interno - 1507794 - RODRIGO JULIANI SIQUEIRA DALMOLIN