The kinetic of corrosion processes was evaluated from the Tafel polarization curves and the quantitative information is given in Table . The poor corrosion resistance of the SS304 sample in the S1 medium is evaluated from the large icorr (2.67 µA/cm 2 ) and the corresponding corrosion rate of 34.91 µm-year -1 . However, appreciably small icorr (0.13 µA/cm 2 ) of the SS304 sample in S2 medium validated the corrosion inhibitive effects of the PA-ZK biofilm. On the other hand, a large corrosion rate (28.02 µm-year -1 ) of the SS304 in the S3 medium validated the poor barrier characteristics of the BS-S1X biofilm. The inhibitive action of the biofilm can be estimated by comparing the Tafel slope values (βa and βc). For instance, the large βa and βc (0.15 and 0.2 V/decade, respectively) values of the SS304 in the S2 medium were attributed to barrier characteristics of the biofilm. On the other hand, comparatively small βa and βc values were registered by the SS304 sample in S1 and S3 media. This corresponded to the progress of localized reactions within the porous structure of the film as evident from the presence of pits on the surface of the SS304 (Figures and). The presence of surface layer (in case of the S1 medium) and biofilms (in the case of S2 and S3 media) could preferentially cover the cathodic regions on the SS304 sample and may impede the corrosion process as confirmed from the relatively large βc values compared to βa. However, the formation of a non-homogeneous surface layer in the S1 medium and the presence of porous structure of the biofilm in the S3 medium facilitated the localized corrosion reactions. However, the limited approach of the ionic species through the compact biofilm produced by PA-ZK bacteria in the S2 medium controlled the dissolution of the SS304. This behavior can also be validated from the impedance data (Table ) and the results are well in agreement with the characteristics of the biofilms as explained above. A noticeable shift in Ecorr to more negative values and relatively large βc values of SS304 in S2 and S3 media compared to S1 medium represented the restricted oxygen reduction reaction owing to the nature of the EPS in the biofilm .