In natural systems phytoplankton interact with planktonic (free living) and attached\nepiphytic bacteria both synergistically and antagonistically. The specificity of the\nassociation with micro algae and bacteria differs in terms of adhesion mechanisms\nand metabolic cooperation. Present research was carried out to study the effect of\nbacterial isolates namely Bacillus sp. and Pseudomonas sp. from algal culture\nsystems on the growth of micro algae such as Chaetoceros calcitrans and\nNannochloropsis oculata. C. calcitrans (F= 15.34; P<0.05) and N. oculata\n(F=12.52; P<0.05) showed significantly higher growth, in treatments with Bacillus\nsp. and Pseudomonas sp when compared to control.