Corrosion Inhibition by Bacteria
Corrosion inhibition is the slowdown of the corrosion reaction usually performed by substances which, when added in small amounts to an environment, decrease the rate of attack by this environment on a metal. Any inhibitory action developed by bacteria may be accomplished within the varied and complex biofilm/corrosion interactions occurring on a biofouled metal surface. Microorganisms can aid in achieving corrosion inhibition according to some of the following mechanisms: neutralizing the action of corrosive substances present in the environment, forming protective films or stabilizing a pre-existing protective film on a metal and inducing a decrease in the medium corrosiveness. When considering the microbial mechanism of corrosion inhibition, it must be highlighted that bacterial metabolism induces complex modifications of the environment, not only through changes in pH, but also through oxygen consumption and production of metabolites, and cellular lysis compounds. The metabolic activity of bacteria is an important factor to consider when explaining microbial inhibition of corrosion.