Influence of surface characteristics and microstructure on adhesion of bacterial cells onto a type 304 stainless steel

A study was carried out to understand the influence of the surface characteristics/microstructure of a type 304 stainless steel on bacterial adhesion by exposing solution-annealed, sensitized and air-oxidized stainless steel specimens in a culture of Pseudomonas sp. in dilute nutrient broth. Epifluorescence microscopy of the exposed surfaces revealed that the pattern of adhesion as well as number density of bacterial cells was different depending on the metallurgical condition of the substratum. Among the specimens with different microstructures, the sensitized specimens had the highest bacterial density, followed by the solution annealed and the oxidized specimens. The same trend was shown by the total viable counts on the various surfaces, estimated by a plate count technique. The study assumes significance in the context of the widely reported observation of preferential attack of the welded region during microbiologically influenced corrosion of fabricated components.