The effects on metal corrosion bySerratia marcescensand aPseudomonasSP.

Publisher Website
Google Scholar
Abstract
Corrosion of steel (SIS 1146) by two marine isolates, Serratia marcescens EF190 and a Pseudomonas sp. S9 was investigated by weight loss measurements of metal coupons placed in static batch cultures. Cell suspensions with and without nutrients were compared with cell free extracts of cultures and uninoculated controls. Adhesion of cells to the metal surface was quantified microscopically. Corrosion was inhibited in all the cell suspensions compared to the sterile controls and cell‐free extracts of the cultures. In the starvation cultures, Pseudomonas S9 caused less corrosion than S. marcescens. This difference between the species was not observed in the cell‐free extracts of the two organisms. A mixed starvation culture with equal parts of 5. marcescens and Pseudomonas S9 resulted in a corrosion rate equal to that of S. marcescens cultures. Purified S9 polymer had no effect on the corrosion rate in an S. marcescens starvation suspension. Because the corrosion inhibition was observed only in the presence of bacterial cells it may have been an effect of cells adhering to the metal surface. The lower Eh of growth cultures compared to starvation suspensions and cell‐free extracts does not appear to reduce the corrosion.