The biocorrosion behavior of the SS304 disc samples was determined in a controlled medium and media containing two different bacterial strains. For instance, 0.5 litres sterile MSM was used as a controlled medium designated as system 1 (S1). System 2 (S2) and 3 (S3) were composed of inoculum of 2.5 ml (0.5 %) of each P. aeruginosa strain ZK and B. subtilis strains, respectively seeded in the MSM (S1). For instance, in S2 and S3 media, the initial bacterial dose of 6.3×10 6 cfu/ml (P. aeruginosa ZK) and 8.4×10 3 cfu/ml (B. Subtilis S1X) was added in the S1 medium. In these media, sodium chloride 3% (w/v) was also added as a background solution. The SS304 disc samples were immersed in these media separately and incubated at 37 °C for two weeks. Postsurface characterization of the disc samples was carried out to examine the extent of surface damage caused by the bacterial strains. Briefly, to study the compactness of biofilms formed on the surface of SS304 samples, the biofilms were fixed on the surface using 3 % glutaraldehyde.