Isolation and characterization of Antarctic bacteria with protease activities

Abstract

Proteases, being one of the largest groups of industrial enzymes, have been used in a wide range of applications including protein stain removal, fuel, food preparation, biofilm removal, leather preparation, and so on. Microorganisms represent an excellent source of protease enzymes owing to their broad biochemical diversity and their susceptibility to genetic manipulation. As an effort to unearth new microbial resources for proteases, we have screened Antarctic soils for the presence of proteolytic bacteria using casein and keratin as substrates, respectively. A total of 169 bacterial genera were identified including Pseudomonas (109), Bacillus (9), Thermoleophilum (11), Micro- coccus (6), Chryseobacterium (2), Arthrobacter (3), Stenotrophomonas (3), Sporocarcina (2), Paenibacillus (1), Planococcus (1), and unclassified Bacteria (22) after screening 100 different soil samples. Strains showing keratinase activity were further screened for caseinase enzyme activity. 28 strains from 53 strains showing keratinase enzyme activity also showed caseinase enzyme activity.