36-39L-asparaginase activity of bacteria, isolated from estuarine sediments and mollusc Villorita cyprinoids, was studied in 642 strains. Based on the activity, these strains were divided into 5 groups. The maximum activity was shown by Aeromonas followed by Pseudomonas, Vibrio and Alkaligens. Specific activity was higher in bacteria isolated from mollusc than from sediments, whereas L-asparaginase positive strains were higher in sediments than in mollusc. The microbial population increased with increase of organic carbon content and decreased with increase of phosphate and nitrate. Percentage of L-asparaginase positive strains decreased with increase of organic carbon