Severe corrosion of carbon steel in oil field produced water can be linked to methanogenic archaea containing a special type of [NiFe] hydrogenase

Abstract

Methanogenic archaea have long been implicated in microbially influenced corrosion (MIC) of oil and gas infrastructure, yet a first understanding of the underlying molecular mechanisms has only recently emerged. We surveyed pipeline-associated microbiomes from geographically distinct oil field facilities and found methanogens to account for 0.2 – 9.3% of the sequenced communities. Neither the type nor the abundance of the detected methanogens correlated to the perceived severity of MIC in these pipelines. Using fluids from one pipeline, MIC was reproduced in the laboratory, both under stagnant conditions and in customized corrosion reactors simulating pipeline flow. High corrosion rates (up to 2.43 mm Fe0 yr−1) with macroscopic, localized corrosion features were attributed to lithotrophic, mesophilic microbial activity. Other laboratory tests with the same waters yielded negligible corrosion rates (< 0.08 mm Fe0 yr−1). Recently a novel [NiFe] hydrogenase, from Methanococcus maripaludis strain OS7, was demonstrated to accelerate corrosion. We developed a specific qPCR assay and detected the gene encoding the large subunit of this hydrogenase (labelled micH) in corrosive (> 0.15 mm Fe0 yr−1) biofilms. The micH gene on the other hand was absent in non-corrosive biofilms despite an abundance of methanogens. Reconstruction of a nearly complete Methanococcus maripaludis genome from a highly corrosive mixed biofilm revealed micH and associated genes in near-identical genetic configuration as strain OS7, thereby supporting our hypothesis that the encoded molecular mechanism contributed to corrosion. Lastly, the proposed MIC biomarker was detected in multiple oil fields, indicating a geographically widespread involvement of this [NiFe] hydrogenase in MIC.IMPORTANCEMicroorganisms can deteriorate built environments, which is particularly problematic in the case of pipelines transporting hydrocarbons to industrial end users. MIC is notoriously difficult to detect and monitor and as a consequence, is a particularly difficult corrosion mechanism to manage. Despite the advent of molecular tools and improved microbial monitoring strategies for oil and gas operations, specific underlying MIC mechanisms in pipelines remain largely enigmatic. Emerging mechanistic understanding of methanogenic MIC derived from pure culture work allowed us to develop a qPCR assay that distinguishes technically problematic from benign methanogens in a West African oil field. Detection of the same gene in geographically diverse samples from North America hints at the widespread applicability of this assay. The research presented here offers a step towards a mechanistic understanding of biocorrosion in oil fields and introduces a binary marker for (methanogenic) MIC that can find application in corrosion management programs in industrial settings.

Cytochrome‐mediated direct electron uptake from metallic iron by Methanosarcina acetivorans

“…The finding that outer‐surface multiheme cytochromes are key electrical contacts for direct metal‐to‐microbe electron transfer in M. acetivorans as well as Geobacter 9,12 and Shewanella 13 species suggests that metagenomic mining for similar cytochrome sequences may aid in determining the relative importance of direct electron uptake on corroding surfaces versus other corrosion mechanisms, such as enhanced H 2 production with extracellular hydrogenases 4 that may also be revealed with molecular analyses. Expanding corrosion studies to a wider diversity of microbes seems likely to not only advance the molecular diagnosis of corrosion mechanisms but also suggest novel strategies for corrosion mitigation.…”

“…Most studies of microbial corrosion have focused on sulfate-reducing bacteria because anoxic sulfate-rich environments are particularly corrosive 2,3 . However, methane-producing archaea are often abundant on the surfaces of corroding iron metals and several methanogen isolates promote corrosion [4][5][6][7][8] .…”

H2is a Major Intermediate inDesulfovibrio vulgarisCorrosion of Iron

“…However, microbes other than sulfate reducers are also likely to contribute to corrosion (3, 30, 38, 39). Elucidating the mechanisms by which a diversity of microbes accelerate corrosion is essential for understanding why corrosion takes place, predicting corrosion rates under various environmental conditions, and developing strategies for corrosion prevention.…”

Iron corrosion by methanogenic archaea characterized by stable isotope effects and crust mineralogy

“…By contrast, the δ 13 C CH4 and δ 2 H CH4 during Fe 0 -dependent growth were rather similar to delta values assigned so far to acetoclastic methanogenesis. We, therefore, propose that the stable isotope composition determined here could be used to diagnose corrosion when correlated with other parameters, like microbial community profiling (Little et al, 2006), corrosion-specific marker genes (Lahme et al, 2021) or mineralogical fingerprinting (McNeil et al, 1991).…”

“…Loss of this genomic region, dubbed MIC island, led to corrosion-deficient M. maripaludis strains (Tsurumaru et al, 2018). Genes encoding similar [NiFe] hydrogenases have been recently detected in several oil fields, indicating a widespread occurrence of this mechanism (Lahme et al, 2021).…”