Banca de DEFESA: ALAINE DE BRITO GUERRA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : ALAINE DE BRITO GUERRA
DATA : 27/02/2018
HORA: 14:00
LOCAL: Sala SS1 do Depto. de Biologia Celular e Genética, do Centro de Biociências
TÍTULO:

Obtaining microbial consortia for biotechnological application in bioremediation

PALAVRAS-CHAVES:

Drill cuttings; microbial consortium; metagenome; biodegradation; biosurfactants.

PÁGINAS: 94
GRANDE ÁREA: Ciências Biológicas
ÁREA: Biologia Geral
RESUMO:

Drill cutting is characterized as a waste without adequate treatment, which has been accumulated generating an environmental liability of large proportions Thus, knowledge of the microbial community and its functions in the drilling cutting can be useful for the development of bioremediation strategies. In this context, the present work aims to identify microorganisms from drill cutting by metagenomic approach and obtain bacterial consortia and isolated bacteria that have hydrocarbon degradation activity and/or biosurfactant production, aiming at application in strategies of bioremediation. Total DNA was directly extracted from the drill cutting samples and from two consortia (enriched in different culture media) and sequenced using the Ion Torrent PGM platform. Isolated bacteria from the consortia were identified by sequencing of 16S rDNA by the Sanger method. Taxonomic analysis revealed changes at the phylum level and consequently genera among the samples. While in the drilling cutting predominated phylum Proteobacteria and genus Halomonas, in the consortia greater abundance were observed for the phylum Firmicutes and genera Paenibacillus and Brevibacillus. Functional analysis using a specific database for hydrocarbon degradation and biosurfactant production (BioSurfDB), revealed that the selection not only maintained routes related to hydrocarbon degradation and biosurfactant production, but also favored some them. Growth curve in the presence of petroleum, colorimetric degradation test using the DCPIP indicator and emulsification tests indicated capacity of hydrocarbon degradation and production of biosurfactants by the consortia and isolated. Returning to the residue to which they were obtained, the consortia selected in LB and YPD medium were able to degrade 66 and 35% of n-alkanes, respectively. So, differences in the composition of microorganisms, probably due to the enrichment stage in different media, reflected different metabolic capacities. LB medium has selected microbial community more adequate to the removal of alkanes in the drill cutting. The 16S rDNA sequences obtained from isolated strains submitted to phylogenetic analyzes by different methods suggest that the target sequences of this work represent candidates to new strains belonging to the clades Brevibacillus, Micrococcus, Bacillus. Metagenomics was shown as a powerful tool in the analysis of microbial communities and the choice of bioremediation strategy. Autochthonous bioaugmentation can be an efficient alternative in hydrocarbon degradation. Method of enrichment through different medium can affect the composition of the microbial community and degradation ability. In addition, through this method possibly new microorganisms could be isolated.

MEMBROS DA BANCA:
Interno - 1346198 - EVERALDO SILVINO DOS SANTOS
Interno - 1453487 - KATIA CASTANHO SCORTECCI
Presidente - 1149647 - LUCYMARA FASSARELLA AGNEZ
Externo à Instituição - MARILENE HENNING VAINSTEIN - UFRGS
Externo à Instituição - VALERIA MAIA DE OLIVEIRA - UNICAMP