1Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran, Iran. Department of Pharmaceutical Biotechnology, Faculty of Pharmacy and Biotechnology Research Center, Tehran University of Medical Sciences, P.O. Box 14155-6451, Tehran, 14174, Iran.
2Department of Pharmaceutical Biotechnology, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, P.O.Box 14155-6153, Iran.
3Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran, Iran.
4Food and Drug Laboratory Research Center, Ministry of Health and Medical Education, Tehran, Iran.
5Department of Food and Drug Control, Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, P.O. Box 14155-6451, Tehran, 14174, Iran.
A soil bacterium capable of degrading chitin on chitin agar plates was isolated and identified as Bacillus pumilus isolate U5 on the basis of 16S rDNA sequence analysis. In order to optimize culture conditions for chitinase production by this bacterium, a two step approach was employed. First, the effects of several medium components were studied using the Plackett-Burman design. Among various components tested, chitin and yeast extract showed positive effect on enzyme production while MgSO4 and FeSO4 had negative effect. However, the linear model proved to be insufficient for determining the optimum levels for these components due to a highly significant curvature effect. In the second step, Box-Behnken response surface methodology was used to determine the optimum values. It was noticed that a quadratic polynomial equation fitted he experimental data appropriately. The optimum concentrations for chitin, yeast extract, MgSO4 and FeSO4 were found to be 4.76, 0.439, 0.0055 and 0.019 g/L, respectively, with a predicted value of chitinase production of 97.67 U/100 mL. Using this statistically optimized medium, the practical chitinase production reached 96.1 U/100 mL.