Dissimilatory Sulfate Reduction Under High Pressure by Desulfovibrio alaskensis G20

Frontiers in Microbiology

Adam J. Williamson¹  Leah L. Huang¹  Hans K. Carlson²  John D. Coates²  Jennifer V. Kuehl³  Adam Deutschbauer³  Anthony T. Iavarone⁴ 

[1] Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, United States;Energy Biosciences Institute, Berkeley, CA, United States;Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, United States;QB3/Chemistry Mass Spectrometry Facility, University of California, Berkeley, Berkeley, CA, United States;

关键词: sulfate reduction;    souring;    sulfidogenesis;    oil reservoirs;    perchlorate;    nitrate;   

DOI  :  10.3389/fmicb.2018.01465

来源: DOAJ

【 摘 要 】

Biosouring results from production of H2S by sulfate-reducing microorganisms (SRMs) in oil reservoirs. H2S is toxic, corrosive, and explosive, and as such, represents a significant threat to personnel, production facilities, and transportation pipelines. Since typical oil reservoir pressures can range from 10 to 50 MPa, understanding the role that pressure plays in SRM metabolism is important to improving souring containment strategies. To explore the impact of pressure, we grew an oil-field SRM isolate, Desulfovibrio alaskensis G20, under a range of pressures (0.1–14 MPa) at 30°C. The observed microbial growth rate was an inverse function of pressure with an associated slight reduction in sulfate and lactate consumption rate. Competitive fitness experiments with randomly bar-coded transposon mutant library sequencing (RB-TnSeq) identified several genes associated with flagellar biosynthesis and assembly that were important at high pressure. The fitness impact of specific genes was confirmed using individual transposon mutants. Confocal microscopy revealed that enhanced cell aggregation occurs at later stages of growth under pressure. We also assessed the effect of pressure on SRM inhibitor potency. Dose-response experiments showed a twofold decrease in the sensitivity of D. alaskensis to the antibiotic chloramphenicol at 14 MPa. Fortuitously, pressure had no significant influence on the inhibitory potency of the common souring controlling agent nitrate, or the emerging SRM inhibitors perchlorate, monofluorophosphate, or zinc pyrithione. Our findings improve the conceptual model of microbial sulfate reduction in high-pressure environments and the influence of pressure on souring inhibitor efficacy.

【 授权许可】

Unknown