Abstract

The marine biofilm bacteria were isolated on polyvinyl chloride (PVC) sheet immersed from offshore platform of Central Electrochemical Research Center (CECRI), Tuticorin, Tami Nadu. The isolated marine biofilm bacteria such as Pseudomonas sp., Aeromonas sp., Enterobacter sp., Bacillus spp., Flavobacterium sp., Microccocus sp. and Cytophaga sp were identified up to generic level. The Pseudomonas sp. was the dominant, primary biofilm forming bacteria. The cell free crude extract of single (Aeromonas sp.) and co-cultured (Aeromonas sp. + Enterobacter sp.) system showed the significant repellent activity against Pseudomonas sp. The crude fractions were characterized by FTIR for functional group identification and GC-MS for compound identification. The results of FTIR shows different peaks like 3302.16, 2816.56, 1227.44 and 2724.02 cm^–1 indicating the presence of bromine, amine, and phenolic, hydroxyl, amino, carbonyl and phosphoryl functional groups. It was also noted that mixed culture system produced increased level of bacteriocin as compared to single culture system. The chemical characterizations of the inhibitory molecules such as nonane, is common to both single as well as co-culture system. The higher inhibitory activity observed in co-culture system is due to the presence of nonadecane, heneicosane and cholestane compounds. The natural biogenic compounds from the marine bacteria studied have the potential to be used as a substitute to commercial biocides for anti-microfouling.

Key words: Anti-biofilm activity, bacteriocin, nonane, bioactivity, bioremediation.