Toward a better understanding of microbiologically influenced corrosion caused by sulfate reducing bacteria
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2019年第4期
论文作者：Tingyue Gu Ru Jia Tuba Unsal Dake Xu
文章页码：631 - 636
摘 要：Sulfate reducing bacteria（SRB） are often the culprits of microbiologically influenced corrosion（MIC） in anoxic environments because sulfate is a ubiquitous oxidant. MIC of carbon steel caused by SRB is the most intensively investigated topic in MIC because of its practical importance. It is also because biogenic sulfides complicate mechanistic SRB MIC studies, making SRB MIC of carbon steel is a long-lasting topic that has generated considerable confusions. It is expedient to think that biogenic H2S secreted by SRB acidifies the broth because it is an acid gas. However, this is not true because endogenous H2S gets its H+ from organic carbon oxidation and the fluid itself in the first place rather than an external source. Many people believe that biogenic H2S is responsible for SRB MIC of carbon steel. However, in recent years,well designed mechanistic studies provided evidence that contradicts this misconception. Experimental data have shown that cathodic electron harvest by an SRB biofilm from elemental iron via extracellular electron transfer（EET） for energy production by SRB is the primary cause. It has been demonstrated that when a mature SRB biofilm is subjected to carbon source starvation, it switches to elemental iron as an electron source and becomes more corrosive. It is anticipated that manipulations of EET related genes will provide genetic-level evidence to support the biocathode theory in the future. This kind of new advances will likely lead to new gene probes or transcriptomics tools for detecting corrosive SRB strains that possess high EET capabilities.
Tingyue Gu1，Ru Jia1，Tuba Unsal1，Dake Xu2
1. Department of Chemical and Biomolecular Engineering,Institute for Corrosion and Multiphase Technology,Ohio University2. School of Materials Science and Engineering,Northeastern University
摘 要：Sulfate reducing bacteria（SRB） are often the culprits of microbiologically influenced corrosion（MIC） in anoxic environments because sulfate is a ubiquitous oxidant. MIC of carbon steel caused by SRB is the most intensively investigated topic in MIC because of its practical importance. It is also because biogenic sulfides complicate mechanistic SRB MIC studies, making SRB MIC of carbon steel is a long-lasting topic that has generated considerable confusions. It is expedient to think that biogenic H2S secreted by SRB acidifies the broth because it is an acid gas. However, this is not true because endogenous H2S gets its H+ from organic carbon oxidation and the fluid itself in the first place rather than an external source. Many people believe that biogenic H2S is responsible for SRB MIC of carbon steel. However, in recent years,well designed mechanistic studies provided evidence that contradicts this misconception. Experimental data have shown that cathodic electron harvest by an SRB biofilm from elemental iron via extracellular electron transfer（EET） for energy production by SRB is the primary cause. It has been demonstrated that when a mature SRB biofilm is subjected to carbon source starvation, it switches to elemental iron as an electron source and becomes more corrosive. It is anticipated that manipulations of EET related genes will provide genetic-level evidence to support the biocathode theory in the future. This kind of new advances will likely lead to new gene probes or transcriptomics tools for detecting corrosive SRB strains that possess high EET capabilities.
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