Microbiologically Influenced Corrosion by Thiosulfate-reducing and Nitrate-reducing Bacteria Isolated from a Natural Gas and Iodine Recovery Facility

Fourteen bacterial strains were isolated from sediments collected at a natural gas and iodine recovery facility in Chiba, Japan. Based on 16S rRNA gene sequence similarity, these strains were related to phyla Actinomycetota, Bacillota, Bacteroidota, Spirochaetota, Synerigystota or Thermodesulfobacteriota. When the bacterial strains were grown anaerobically in the presence of an iron (Fe0) foil, the Fe0 foil in the five cultures of Fusibacter sp. NT003, Proteiniclasticum sp. NT002, Tissierella sp. NT019 and Seleniibacterium sp. NT022, was oxidized in the presence of thiosulfate. The amount of oxidized iron in these cultures was 3.0–10.6 times higher than in the aseptic control. Similarly, the Fe0 foil in the three cultures of Actinotalea sp. NT006, Maribellus sp. NT033 and Seleniibacterium sp. NT022 was oxidized in the presence of nitrate. The amount of oxidized iron in these cultures was 5.2–14.2 times higher than in the aseptic control. The Fe0 foil in the cultures of the remaining eight strains including Dethiosulfovibrio sp. NT041 was not oxidized in both culture conditions in the presence of thiosulfate or nitrate. This is the first report of microbiologically influenced corrosion by the member of six genera Actinotalea, Tissierella, Fusibacter, Maribellus, Seleniibacterium, and Proteiniclasticum.