A recent press release by National Institute for Materials Science (Japan) has found Corrosion eating Enzymes that may offer a more environmentally friendly way to control corrosion in Pipelines
A research team led by NIMS and RIKEN has discovered that sulfate-reducing bacteria responsible for anaerobic iron corrosion in petroleum pipelines, etc. possess a group of cell surface enzymes which enable them to directly extract electrons from extracellular solids. Current anticorrosion methods involve the use of antibacterial agents which kill a broad spectrum of bacteria. Their finding may facilitate the development of more efficient and environmental-friendly anti-biocorrosion methods; for example, the formulation of chemicals capable of effectively inhibiting the bacterial enzymes identified in this research.
Bacterial reduction of oxidized sulfur species (OSS) is critical for energy production in anaerobic marine subsurfaces. In organic-poor sediments, H2 has been considered as a major energy source for bacterial respiration. We identified outer-membrane cytochromes (OMCs) that are broadly conserved in sediment OSS-respiring bacteria and enable cells to directly use electrons from insoluble minerals via extracellular electron transport. Biochemical, transcriptomic, and microscopic analyses revealed that the identified OMCs were highly expressed on the surface of cells and nanofilaments in response to electron donor limitation. This electron uptake mechanism provides sufficient but minimum energy to drive the reduction of sulfate and other OSS. These results suggest a widespread mechanism for survival of OSS-respiring bacteria via electron uptake from solid minerals in energy-poor marine sediments.