Nitrite as a causal factor for nitrate-dependent anaerobic corrosion of metallic iron induced by Prolixibacter strains

Abstract

Microbially influenced corrosion (MIC) may contribute significantly to overall corrosion risks, especially in the gas and petroleum industries. In this study, we isolated four Prolixibacter strains, which belong to the phylum Bacteroidetes, and examined their nitrate-respiration- and Fe0-corroding activities, together with two previously isolated Prolixibacter strains. Four of the six Prolixibacter strains reduced nitrate under anaerobic conditions, while the other two strains did not. The anaerobic growth of the four nitrate-reducing strains was enhanced by nitrate, which was not observed in the two nitrate-non-reducing strains. When the nitrate-reducing strains were grown anaerobically in the presence of Fe0 or carbon steel, the corrosion of the materials was enhanced by more than 20-fold compared to that in aseptic controls. This enhancement was not observed in cultures of the nitrate-non-reducing strains. The oxidation of Fe0 in the anaerobic cultures of nitrate-reducing strains occurred concomitantly with the reduction of nitrite. Since nitrite chemically oxidized Fe0 under anaerobic and aseptic conditions, the corrosion of Fe0- and carbon-steel by the nitrate-reducing Prolixibacter strains was deduced to be mainly enhanced via the biological reduction of nitrate to nitrite, followed by the chemical oxidation of Fe0 to Fe2+ and Fe3+ coupled to the reduction of nitrite.

Iron corrosion concomitant with nitrate reduction by Iodidimonas nitroreducens sp. nov. isolated from iodide-rich brine associated with natural gas

“…Interestingly, in the presence of Fe 0 , nitrite increased until day 4, and decreased from day 7; ammonium increased more than in the absence of Fe 0 . This was demonstrated by nitrite-induced chemical corrosion of Fe 0 because nitrite oxidizes Fe 0 in a concentration-dependent manner, as previously shown (Iino et al, 2021b). Evidence that nitrite produced by biological nitrate reduction was the primary causal agent of Fe 0 corrosion is shown in Figure 2, where nitrite reduction occurred in parallel with Fe 0 oxidation.…”

“…Previously, Prolixibacter denitrificans and Prolixibacter sp. strain SD074, isolated from an oil well and a crude oil storage tank, have shown to corrode Fe 0 with concomitant nitrate reduction under anaerobic conditions (Iino et al, 2015(Iino et al, , 2021b. Iron corrosion by the nitrate-reducing bacterium I. nitroreducens Q-1 T has shown that MIC occurs not only under anaerobic conditions but also under aerobic conditions in oil fields and iodine production facilities.…”

Impact of Bio-Competitive Exclusion on Nitrate-Reducing Bacteria in Oil Reservoir Water Treatment

“…To lessen the risk of sulphate corrosion in the complex storage tank, the optimum ratio of inoculating NRB to nitrate, nitrite, and molybdate was identified over a range of conditions. By using this measure, we were able to prevent sulphate-related damage to the reservoir [11].…”