TY - JOUR ID - 71792 TI - Production of Extracellular Protease and Determination of Optimal Condition by Bacillus Licheniformis BBRC 100053 (RESEARCH NOTE) JO - International Journal of Engineering JA - IJE LA - en SN - 1025-2495 AU - Haji Hosseini, Reza AU - Yaghmaei, S. AU - Ghobadi, Zahra AD - Department of Science, Payame Noor University AD - Department of Chemical and Petroleum Engineering, Sharif University of Technology AD - Biochemical and Bioenvironmental Research Center, Sharif University of Technology Y1 - 2009 PY - 2009 VL - 22 IS - 3 SP - 221 EP - 228 KW - Protease KW - Bacillus licheniformis KW - Thermo Stable Protease KW - Enzyme KW - optimization DO - N2 - The production of protease by Bacillus licheniformis BBRC 100053 was studied. The most appropriate medium for the growth and protease production is composed of: lactose 1%, yeast extract 0.5%, peptone 0.5%, KH2PO4 0.1%, MgSO4.7H2O 0.02%. Enzyme production corresponded with growth and reached a maximums level (589 U/ml) during the stationary phase at 35°C, pH equivalent to 10 and with 150 rpm after 73 hours. Protease activity was highest at pH 8 and 45°C. The best carbon sources are respectively lactose and maltose and the best nitrogen source is peptone. The protease was highly active and stable from pH 7.0 to 11.0 with an optimum at pH 7-8. Thermo stability of the enzyme was considered in the presence and absence of 2mM CaCl2. Enzyme is non stable at temperatures higher than 50°C while the thermal stability was enhanced in the presence of Ca2+. The enzyme retained 15 and 8% of its initial activity after heating for 60min at 60°C in the presence and absence of 2mM CaCl2, respectively and retained 7 and 3% of at 70°C in the presence and absence of 2mM CaCl2. . UR - https://www.ije.ir/article_71792.html L1 - https://www.ije.ir/article_71792_a7204d8011cb1b771e201025b0df0ad2.pdf ER -