Biofouling of Titanium – Biomineralization and Corrosion Aspects

Manganese oxidizing bacteria colonizing the titanium surfaces exposed to seawater were characterized by periodically retrieving the coupons over a period of two years. About 20% of the initial colonizers were capable of oxidizing manganese, and the dominant manganese oxidizing bacteria were those belonging to Gram negative Pseudomonas spp. Gram positive, Bacillus spp, were also observed, though in smaller population. Almost 40-60% of the biofilm formers observed during 1 – 5 months were capable of oxidizing manganese. There was a gradual shift in biofilm colonisers from Gram negative to Gram positive bacteria, with Gram positive members increasing in numbers and diversity with time. Sulphate reducing bacteria (SRB) capable of growth under anaerobic conditions were also isolated from the biofilms even as early as two days of exposure to seawater. Different species of marine SRBs belonging to the genus Desulfovibrio and Desulfotomaculum were isolated.