Microbial community characteristics of petroleum reservoir production water amended with n-alkanes and incubated under nitrate-, sulfate-reducing and methanogenic conditions

• Published in: International biodeterioration & biodegradation Vol. 69; pp. 87 - 96
• Main Authors: Li, Wei, Wang, Li-Ying, Duan, Ruo-Yu, Liu, Jin-Feng, Gu, Ji-Dong, Mu, Bo-Zhong
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2012
• Subjects: Actinobacteria; alkanes; Amplification; chemical analysis; Communities; community structure; Crenarchaeota; Crude oil; Degradation; delta-Proteobacteria; DNA; energy; Enrichment; Enrichment cultures; Functional genes; gamma-Proteobacteria; gene amplification; Genes; metabolism; methanogens; Methanomicrobiales; Microbial communities; Microorganisms; Nitrospira; nucleotide sequences; oil fields; oils; petroleum; Petroleum reservoirs; phylogeny; remediation; Reservoirs; ribosomal RNA; China; Microbial communities; Petroleum reservoirs; Functional genes; Enrichment cultures
• ISSN: 0964-8305; 1879-0208
• DOI: 10.1016/j.ibiod.2012.01.005

Methanogenic, sulfate- and nitrate-reducing enrichment cultures amended with long-chain n-alkanes (C15–C20) were established with production water from Huabei oilfield in China in the present study. Chemical analyses indicated that degradation of n-alkanes was evident under all three conditions after 356 days of incubation. Phylogenetic analyses based on 16S rRNA gene amplification indicated that α-, β-, γ-Proteobacteria and Bacteroidetes were detected in the nitrate-reducing enrichment; Actinobacteria, Nitrospira and δ-Proteobacteria were recovered from both the sulfate-reducing and methanogenic enrichments. Actinobacteria and Nitrospira were the most abundant in methanogenic and sulfate-reducing enrichment, respectively. The archaeal clone libraries showed that the order Methanomicrobiales within the phylum Euryarchaeota predominated methanogenic enrichment; whereas the unclassified class Thermoprotei within the phylum Crenarchaeota prevailed in sulfate-reducing enrichment. Comparison of 16S rRNA gene sequences from genomic DNA extracted directly from the petroleum reservoir production water with those from the three active enrichments showed that the available electron acceptors had a strong influence on the microbial community composition. In addition, genes encoding the alkylsuccinate synthase (assA) and methyl coenzyme-M reductase (mcrA) were amplified from the methanogenic enrichment and the results suggested that fumarate addition was probably involved in the degradation of n-alkanes. These results shed light on the potential utilization of microbial metabolism in remediation of hydrocarbon contamination or in enhancing the recovery of residual oil for energy. ► We obtained n-alkanes-degrading enrichment cultures under three reducing conditions. ► The n-alkanes degradation linked to nitrate-, sulfate-reduction and methanogenesis was observed. ► The genes of assA and mcrA were amplified from methanogenic cultures. ► Electron acceptors had a strong influence on the microbial community composition.