Corrosion characteristics of sulfate-reducing bacteria (SRB) and the role of molecular biology in SRB studies: an overview

Sulfate-reducing bacteria (SRB), an anaerobic bacterial group, are found in many environments like freshwater, marine sediments, agricultural soil, and oil wells where sulfate is present. SRB derives energy from electron donors such as sulfate, elemental sulfur or metals, and fermenting nitrate. It is the major bacterial group involved in the microbiologically influenced corrosion (MIC), souring, and biofouling problems in oil-gas-producing facilities as well as transporting and storage facilities. SRB utilizes sulfate ions as an electron acceptor and produce H2S, which is an agent of corrosion, causing severe economic damages. Various theories have been proposed on the direct involvement of H2S and iron sulfides in corrosion; H2S directly attacks and causes corrosion of metals and alloys. Many reviews have been presented on the aforementioned aspects. This review specifically focused on SRB corrosion and the role of molecular biology tools in SRB corrosion studies viz. cathodic and anodic depolarization theories, corrosion characteristics of thermophilic SRB and influence of hydrogenase, temperature, and pressure in thermophilic SRB corrosion, SRB taxonomy, molecular approaches adopted in SRB taxonomical studies, sulfate and citrate metabolism analyses in completed SRB genomes, and comparative studies on SRB’s dissimilatory sulfite reductase structures.