Isolation and screening of Bacillus subtilis isolated from the dairy effluent for the production of protease

Proteases are a group of enzymes, found in all living organisms and are essential for the cell growth and differentiation. The proteases have wide applications in pharmaceutical, leather, laundry, food and waste processing industries. Their catalytic function is to hydrolyze peptide bonds of proteins and break them down into polypeptides or free amino acids. The present study was aimed at isolating Bacillus subtilis from a dairy effluent obtained from a local retailer. Bacillus subtilis was isolated using the serial dilution method and the identification of bacterial population was done using morphological examination and biochemical characterization. The culture was maintained in two different media that were prepared from rice bran and groundnut cake. The study of the factors namely pH and temperature, that influence protease activity was also done. Results show that maximum activity could be obtained in rice bran medium and shows that the rice bran medium to be the optimal medium for the growth of Bacillus subtilis isolated from the dairy effluent for the production of protease. The optimal conditions for maximal activity was found to be at a pH of 7 and at a temperature of 35°C.From the current study it is evident that the protease produced byisolated Bacillus species was a neutral protease that are of great importance in detergent industry due to their high thermostability and pH stability K e y w o r d s