Microscopical Observation of the Marine Bacterium Vibrio Natriegeus Growth on Metallic Corrosion

Biofilm formation and the adsorption of nonsulfate-reducing marine bacterium Vibrio natriegens (V. natriegens) to different metallic surfaces have been studied by atomic force microscopy (AFM). The nature of extracellular polymeric substance (EPS) has been monitored through the force-distance curve. EPS may act as adhesive binding adjacent cells and thus further enhance the aggregation of microbes during cluster formation due to its adhesiveness in nature. The AFM images supplied the change of the morphology of microbial cells and colonies, the distribution of microbial colonies, and the presence of EPS on the surfaces with immersion. Results showed that the biofilms formed on the surfaces increased in thickness and heterogeneity with time and that 3–7 days was the proliferation period of the bacteria on metallic surfaces. The corrosion type of the metals by V. natriegens could be confirmed as typical pitting attack through scanning electron microscopy (SEM) observation.