Utilization of cathodic hydrogen by hydrogen-oxidizing bacteria

Summary Hydrogen is consumed by methanogenic, sulphate-reducing, and homoacetogenic bacteria and members of these bacterial groups are able to grow chemolithotrophically with hydrogen as sole energy source. Cathodic hydrogen consumption by sulphate-reducing bacteria has been proposed as one of the factors in the anaerobic corrosion of metals. Desulfovibrio spp. were able to utilize cathodic hydrogen from mild steel as the only source of energy for growth with sulphate or nitrate as terminal electron acceptor. Other hydrogen-oxidizing bacteria such as Methanospirillum hungatei, Acetobacterium woodii and Wolinella succinogenes were also able to utilize cathodic hydrogen from mild steel for energy generation and growth. Weight loss studies of mild steel coupons under different growth conditions of Desulfovibrio spp. indicated that hydrogen removal alone is not the cause of corrosion and the depolarization phenomenon probably plays a role only in the initiation of the anaerobic microbial corrosion process.