What is biocorrosion?

Abstract

Microorganisms growing on surfaces perform a variety of metabolic reactions, the products of which may promote the deterioration of the underlying substratum. These reactions refer to biocorrosion when the substratum consists of a metal or metal alloy. The effect of corrosive microbial products on an underlying metal surface is exacerbated when their concentrations are permitted to increase to high levels as may occur when the microorganisms grow on the surface in a biofilm. The biofilm contains exopolymers which impede the diffusion of solutes and gases between the surface and the bulk aqueous phase. The biofilm also permits the development of highly structured microbial communi-ties on the surface. The various species are able to collectively carry out metabolic activities that are potentially more corrosive to the underlying surface than could be achieved by a single species acting alone. These features of sessile microbial growth represent important prerequisites of biocorrosion.