Study was carried out on the distribution of bacterioplankton in the Indian sector of Southern Ocean. Total Heterotrophic Bacterial (THB) counts were maximum (107x104/CFU/ml) in water samples collected from 200 m depth and lowest (15.1x103/CFU/ml) at 3730 m. Of the 250 strains isolated from the water samples, 9.2% were gram positive and 4.8% gram negative. The important genera encountered were Pseudomonas, Aeromonas, Vibrio, Acinetobacter, Micrococcus, Staphylococcus, Corynebacterium, Flavobacterium, Chromobacterium, Moraxella, Bacillus and Planococcus. Most of the isolates (94%) were capable of lipase production followed by gelatinase (40%) and amylase (32%).

Heterotrophic, bacterioplankton, enzymes, Indian sector, Southern Ocean