Microbial Diversity of Marine Biofilm

Abstract

We isolated culturable bacteria that have inhabited on natural marine biofilms, and identified them by phylogenetic analysis using 16S rDNA sequences. In marine environment, biofilms cover most of subtidal and intertidal solid surfaces such as rocks, ships, loops, marine animal, algae, etc. The bacteria in most biofilms are embedded in extracellular polymeric substances that comprise mainly exopolysaccharides. The main component exopolysaccharides are excreted from multiple bacterial species, therefore, biofilms are good source for screening exopolysaccharide-producing bacteria. Total 31 strains were cultured, among them, 14 strains were overlapped and 17 strains were finally identified. Phylogenetic analysis using 16S rDNA indicated that the 17 strains belonged to a–Proteobacteria (Ochrobactrum anthropi, Paracoccus carotinifaciens); g–Proteobacteria (Pseudoalteromonas piscicida, P. agarovorans, Pseudomonas aeruginosa, Shewanella baltica, Vibrio parahaemolyticus, V. pomeroyi); CFB group bacteria (Cytophaga latercula, Tenacibaculum mesophilum); high GC, Gram positive bacteria (Arthrobacter nicotianae, Brevibacterium casei, B. epidermidis, Tsukamurella inchonensis); and low GC, Gram positive bacteria (Bacillus macroides, Staphylococcus haemolyticus, S. warneri).