Gene Sets and Mechanisms of Sulfate-Reducing Bacteria Biofilm Formation and Quorum Sensing With Impact on Corrosion.

Abhilash Kumar Tripathi,Payal Thakur,Rajesh Kumar Sani,Venkataramana Gadhamshetty,Etienne Z Gnimpieba,Bharat K Jasthi,Ram Nageena Singh,Vinoj Gopalakrishnan,Priya Saxena,Shailabh Rauniyar

doi:10.3389/fmicb.2021.754140

Abstract

Sulfate-reducing bacteria (SRB) have a unique ability to respire under anaerobic conditions using sulfate as a terminal electron acceptor, reducing it to hydrogen sulfide. SRB thrives in many natural environments (freshwater sediments and salty marshes), deep subsurface environments (oil wells and hydrothermal vents), and processing facilities in an industrial setting. Owing to their ability to alter the physicochemical properties of underlying metals, SRB can induce fouling, corrosion, and pipeline clogging challenges. Indigenous SRB causes oil souring and associated product loss and, subsequently, the abandonment of impacted oil wells. The sessile cells in biofilms are 1,000 times more resistant to biocides and induce 100-fold greater corrosion than their planktonic counterparts. To effectively combat the challenges posed by SRB, it is essential to understand their molecular mechanisms of biofilm formation and corrosion. Here, we examine the critical genes involved in biofilm formation and microbiologically influenced corrosion and categorize them into various functional categories. The current effort also discusses chemical and biological methods for controlling the SRB biofilms. Finally, we highlight the importance of surface engineering approaches for controlling biofilm formation on underlying metal surfaces.

Highlights

Sulfur is an abundant element that exists in the forms of pyrite (FeS2), gypsum (CaSO4), and sulfate in the natural environments, including rocks, sediments, and seawater, respectively (Labrado et al, 2019)
Biofilm formed by Sulfate-reducing bacteria (SRB) induces changes on the metal surface that accelerate the anodic/cathodic process, controlling corrosion rates
This review summarized the molecular mechanisms of biofilm formation by SRB and its implications in microbiologically influenced corrosion (MIC)

Summary

Introduction

Sulfur is an abundant element that exists in the forms of pyrite (FeS2), gypsum (CaSO4), and sulfate in the natural environments, including rocks, sediments, and seawater, respectively (Labrado et al, 2019). Sulfur cycling in the environment is dominated by sulfate-reducing bacteria (SRB). Sulfate-Reducing Bacteria Biofilm and sulfur-oxidizing bacteria (SOB) (Zhang et al, 2017). SRB gain energy through dissimilatory sulfate reduction, which is the main process of biomineralization of organic matter in marine sediments. SRB respire using sulfate as a terminal electron acceptor, reducing it to hydrogen sulfide. SRB are of primary concern because they accelerate metallic corrosion under mild conditions, including neutral pH, ambient temperature, and absence of oxygen, both in natural and engineered aquatic systems (Lee et al, 1995; Beech and Sunner, 2007). SRB are often responsible for microbiologically influenced corrosion (MIC), accelerating corrosion reactions, or shifting corrosion mechanisms (Venzlaff et al, 2013; Guan et al, 2016)

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Conclusion