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ISRN Biochemistry
Volume 2013 (2013), Article ID 942590, 10 pages
Research Article

Production of Alkaline Protease by Solvent-Tolerant Alkaliphilic Bacillus circulans MTCC 7942 Isolated from Hydrocarbon Contaminated Habitat: Process Parameters Optimization

1Department of Microbiology, R. C. Patel Arts, Commerce and Science College, Shirpur 425 405, India
2School of Life Sciences, North Maharashtra University, Jalgaon 425 001, India

Received 19 September 2013; Accepted 7 October 2013

Academic Editors: B. Penke and W. Sattler

Copyright © 2013 Ulhas Patil and Ambalal Chaudhari. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


In the present investigation, a newly isolated organic solvent-tolerant and alkaliphilic bacterial strain was reported from a hydrocarbon (gasoline and diesel) contaminated soil collected from the petrol station, Shirpur (India). The strain was identified as Bacillus circulans MTCC 7942, based on phenotype, biochemical, and phylogenetic analysis of 16S rRNA gene sequence. The capability of Bacillus circulans to secrete an extracellular, thermostable, alkaline protease and grow in the presence of organic solvents was explored. Bacillus circulans produced maximum alkaline protease (412 U/mL) in optimized medium (g/L): soybean meal, 15; starch, 10; KH2PO4, 1; MgSO4·7H2O, 0.05; CaCl2, 1; Na2CO3, 8; pH 10.0 at 37°C and 100 rpm. The competence of strain to grow in various organic solvents—n-octane, dodecane, n-decane, N,N-dimethylformamide, n-hexane, and dimethyl sulfoxide, establishes its potential as solvent-stable protease source for the possible applications in nonaqueous reactions and fine chemical synthesis.