Phenotypic and Genotypic Characterization of a Marine Bacterium Isolated from Sundarbans, Bangladesh

The mangrove ecosystem is a largely unexplored source for bacteria with the potentiality to produce biologically active secondary metabolites. Consequently, we set our research study to isolate, characterize and screen a bacterium producing bioactive compounds from marine soil of Sundarbans, Bangladesh. A total number of 39 marine bacterial colonies were isolated and purified. Representative bioactive isolate, ANAM-5 was characterized using phenotypic and genotypic procedures since it exhibited highest antibacterial activity against a series of test organisms. The 16S rDNA sequence of the strain ANAM-5 showed close similarity with only one bacterium Planctomyces brasiliensis, complete genome (99.64%). But the cultural, morphological, physiological and biochemical characteristics of the strain and P. brasiliensis were completely different. So, it may not be logical to assign the strain ANAM-5 to the genus Planctomyces. Thus, to confirm the taxonomic position of the strain and to have a correct solution for this taxonomic problem, further studies are needed in respect to the DNA relatedness studies, fatty acid profiling, DNA-DNA hybridization, matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF), metabolic finger profiling using BIOLOG, ribotyping, small subunit (SSU) sequences, cell wall composition and other characterizations.