MOLMIC · Molecular Biology of Sulfide-Oxidizing Nitrate-Reducing Microorganisms Involved in Microbiologically-Influenced Corrosion

Molecular Biology of Sulfide-Oxidizing Nitrate-Reducing Microorganisms Involved in Microbiologically-Influenced Corrosion

Modern society is striving to orient our energy use towards sustainable ‘green’ energy sources, however, this transition is occurring slowly. Due to the increasing energy demand, fossil fuels will remain crucial for several years during the transition phase towards ‘greener’ solutions. The inevitable depletion of fossil fuel reserves and the devastating effects of oil spills to ecosystem services requires a responsible and sustainable development of the remaining resources during this transition period. Corrosion of steel infrastructure is a multi-billion Euro problem for the oil and gas industry, which can lead to significant costs due to equipment failure as well as risk to the environment. Microorganism can significantly influence corrosion reactions on steel surfaces and this phenomenon is referred to as microbiologically-influenced corrosion (MIC). MIC in the oil industry is often linked to activity of sulfate-reducing microorganisms (SRM), which produce toxic, explosive and corrosive hydrogen sulfide, thus contributing to oil reservoir souring. The formation of sulfide poses a significant threat for worker’s health and safety and decreases product values due to higher sulfur content. Nitrate injection into sour oil fields biologically removes hydrogen sulfide by promoting activity of sulfide-oxidizing nitrate-reducing microorganisms (soNRM). However, recent reports involved soNRM in MIC, threatening application of nitrate as a souring control strategy. The MOLMIC project addressed the Molecular Biology of Sulfide-Oxidizing Nitrate-Reducing Microorganisms Involved in Microbiologically-Influenced Corrosion. The project developed i) a sound understanding of the sulfur metabolism of oil field soNRM, ii) linked different soNRM metabolisms to corrosion and iii) evaluated nitrate-mediated MIC in complex microbial communities. MOLMIC developed an unprecedented understanding of the factors and mechanisms by which soNRMs contribute to corrosion during the injection of nitrate. This information increased our understanding of this bioengineering strategy and is invaluable for the development of targeted gene assays to monitor soNRM activity where nitrate-mediated corrosion might be an issue.

Data: CORDIS, © European Union