title: Microbial diversity in degraded and non-degraded petroleum samples and comparison across oil reservoirs at local and global scales.
abstract: Microorganisms have shown their ability to colonize extreme environments including deep subsurface petroleum reservoirs. Physicochemical parameters may vary greatly among petroleum reservoirs worldwide and so do the microbial communities inhabiting these different environments. The present work aimed at the characterization of the microbiota in biodegraded and non-degraded petroleum samples from three Brazilian reservoirs and the comparison of microbial community diversity across oil reservoirs at local and global scales using 16S rRNA clone libraries. The analysis of 620 16S rRNA bacterial and archaeal sequences obtained from Brazilian oil samples revealed 42 bacterial OTUs and 21 archaeal OTUs. The bacterial community from the degraded oil was more diverse than the non-degraded samples. Non-degraded oil samples were overwhelmingly dominated by gammaproteobacterial sequences with a predominance of the genera Marinobacter and Marinobacterium. Comparisons of microbial diversity among oil reservoirs worldwide suggested an apparent correlation of prokaryotic communities with reservoir temperature and depth and no influence of geographic distance among reservoirs. The detailed analysis of the phylogenetic diversity across reservoirs allowed us to define a core microbiome encompassing three bacterial classes (Gammaproteobacteria, Clostridia, and Bacteroidia) and one archaeal class (Methanomicrobia) ubiquitous in petroleum reservoirs and presumably owning the abilities to sustain life in these environments.
authors.affiliation: Microbial Resources Division, Research Center for Chemistry, Biology and Agriculture (CPQBA), University of Campinas, UNICAMP, Campinas, CEP 13148-218, Brazil. inatalia.sierra@gmail.com.|School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK. inatalia.sierra@gmail.com.
authors.forename: Isabel Natalia
authors.initials: IN
authors.lastname: Sierra-Garcia
authors.affiliation: Microbial Resources Division, Research Center for Chemistry, Biology and Agriculture (CPQBA), University of Campinas, UNICAMP, Campinas, CEP 13148-218, Brazil.
authors.forename: Bruna M
authors.initials: BM
authors.lastname: Dellagnezze
authors.affiliation: Microbial Resources Division, Research Center for Chemistry, Biology and Agriculture (CPQBA), University of Campinas, UNICAMP, Campinas, CEP 13148-218, Brazil.
authors.forename: Viviane P
authors.initials: VP
authors.lastname: Santos
authors.affiliation: Institute of Chemistry, University of Campinas, Campinas, CEP13083-970, Brazil.
authors.forename: Michel R
authors.initials: MR
authors.lastname: Chaves B
authors.affiliation: PETROBRAS/R&D Center, Rio de Janeiro, CEP 21949-900, Brazil.
authors.forename: Ramsés
authors.initials: R
authors.lastname: Capilla
authors.affiliation: PETROBRAS/R&D Center, Rio de Janeiro, CEP 21949-900, Brazil.
authors.forename: Eugenio V
authors.initials: EV
authors.lastname: Santos Neto
authors.affiliation: School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.
authors.forename: Neil
authors.initials: N
authors.lastname: Gray
authors.affiliation: Microbial Resources Division, Research Center for Chemistry, Biology and Agriculture (CPQBA), University of Campinas, UNICAMP, Campinas, CEP 13148-218, Brazil.
authors.forename: Valeria M
authors.initials: VM
authors.lastname: Oliveira
mesh_terms: D001105:Archaea / Q000235:genetics / Q000302:isolation & purification; D053520:Marinobacter / Q000235:genetics / Q000302:isolation & purification*; D064307:Microbiota; D061329:Oil and Gas Fields / Q000382:microbiology*; D010578:Petroleum / Q000378:metabolism; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D010578:Petroleum; D012336:RNA, Ribosomal, 16S
keywords: Degradation; Microbial diversity; Oil; Petroleum reservoirs