Effect of Corrosive Metabolites Produced by the Bacterium Escherichia coli on Zinc Corrosion

摘要

A by-product of oxygen biotransformation during the life of bacteria is the superoxide ion O-2(-), which quite easily, including nonenzymatically, can turn into the stable product H2O2, which, as is well known, may exhibit corrosive properties for metals. Thus, the vital products of bacterial can act on a metal not only as chemical agents, they can also electrochemically stimulate corrosion. To identify the nature of the elementary stages of biocorrosion, an attempt was made to simulate electrochemical corrosion of zinc using well-known electrochemical methods. Zinc corrosion occurs by two electrochemical mechanisms: corrosion by oxygen depolarization and oxidation of zinc by hydrogen peroxide. The limiting stage of the corrosion process is diffusion of the oxidizing agents to the zinc surface.