Journal of Pure and Applied MicrobiologyVol. 9 No. 3

Isolation and Optimization of Proteolytic and Lipolytic Bacteria from Dairy Effluent

P.B. Sridevi, N. Parthasarathy, N. Parthasarathy, S. Thiruvengadam and D. Sridhar

Department of Biotechnology, Rajalakshmi Engineering, College, Chennai 602105, India.

Received on 10 April 2015 and accepted on 10 June 2015



The present study aimed at optimization of the four best isolates selected from both proteolytic (out of 30) and lipolytic (out of 21) based on the maximum zone of clearance. The potential bacterial strains were sequenced and identified as L2 - Lysinibacillus sphaericus, L8 - Pseudomonas taiwanensis, P11 - Bacillus marisflavi and P9 - Pseudomonas aeruginosa by 16s rRNA analysis. Optimization of Protease Enzyme Activity (P9, P11) and Lipase Enzyme Activity (L2, L8) were studied. Peak proteolytic activity for P9 was observed for carbon source as maltose, yeast extract as nitrogen source, wheat bran as substrate, at pH 7.0 and the isolate P11 revealed optimum carbon source as fructose, beef extract as nitrogen source, whey as substrate, at pH 8.0. Similarly, peak lipolytic activity for L2 was observed for carbon source as sucrose, urea as nitrogen source, at pH 7.0, palm oil as substrate and the isolate L8 resulted maltose as carbon source, tryptone as nitrogen source, at pH 7, palm oil as substrate. From the results of the present study, it could be inferred that the isolates from the dairy effluent can be used for effective biological method of the treatment thereby supporting the degradation of organic and inorganic nutrients.

Keywords : Bacterial isolates, Dairy effluent, Proteolytic bacteria, Lipolytic bacteria, Enzyme units.