THE ROLE OF METHANOGENS IN MICROBIOLOGICALLY INFLUENCED CORROSION

Abstract

Microbiological influenced corrosion (MIC) has always been associated with the sulphate-reducing bacteria (SRB) ever since its discovery. However, recent years of research has shown that MIC is not simply the action of SRB. Other microorganisms are also capable of inducing MIC and one of the possible candidates is the archaea species – methanogens which share several similar characteristics with SRB. Drawing inspiration from the research into SRB-influenced corrosion mechanisms, it is discovered that methanogens are able to enhance carbon steel corrosion when they are deprived of their usual energy sources. They actively sought out alternative energy sources for survival maintenance energy production when starvation conditions are triggered and in this case, it is iron oxidation. One possible mechanism for this methanogen-influenced corrosion under starvation conditions is discovered to be through the use of suitable exogenous mediators for electron transfer between carbon steel and the methanogen cells. Vitamin B12 is suggested to be one of them.