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Enzyme Research
Volume 2011, Article ID 219628, 7 pages
Research Article

Effect of Culture Conditions on the Production of an Extracellular Protease by Bacillus sp. Isolated from Soil Sample of Lavizan Jungle Park

1Department of Microbiology, North Tehran Branch of Islamic Azad University, 1667934791 Tehran, Iran
2Department of Biology, Science and Research Branch of Islamic Azad University, 1477893855 Tehran, Iran

Received 5 May 2011; Revised 16 July 2011; Accepted 15 September 2011

Academic Editor: Alane Beatriz Vermelho

Copyright © 2011 Abbas Akhavan Sepahy and Leila Jabalameli. 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.


Soil samples of Tehran jungle parks were screened for proteolytic Bacilli. Among eighteen protease producers one of the isolates obtained from Lavizan park, in north east of Tehran, was selected for further experimental studies. This isolate was identified as Bacillus sp. strain CR-179 based on partial sequencing of 16S rRNA. Various nutritional and environmental parameters affected protease production by Bacillus sp. strain CR-179. Protease production by this Bacillus cultivated in liquid cultures reached a maximum at 24 h, with levels of 340.908 U/mL. Starch and maltose were the best substrates for enzyme production while some pure sugars such as fructose, glucose, and sucrose could not influence production of protease. Among various organic nitrogen sources corn steep liquor, which is commercial, was found as the best substrate followed by yeast extract, whey protein, and beef extract. The optimal pH and optimal temperature of enzyme production were 8.0 and 45°C, respectively. Studies on enzymatic characterization revealed that crude protease showed maximum activity at pH 9.0 and 60°C, which is indicating the enzyme to be thermoalkaline protease.