Statistical Optimization of Cellulase Production byThermomyces dupontii

In the present investigation, significant physical parameters such as incubation time, temperature and pH were optimized for cellulase production by wild and mutant strains of thermophilicThermomyces dupontii. For a comparative analysis, three independent variables which were selected from OVAT were subjected to RSM. As per response surface methodology (RSM) model, central composite design was used in order to analyze the interactive effects of significant physical factors on cellulase productivity. The second polynomial regression model with a determination coefficientR(2)value 0.9503 and 0.9711 was found to be adequate and significant. 3D response surface plots and contours showed interaction among three variables. In contrast to wildT. dupontii, mutant strain showed 1.7-fold increase in FPase activity (43 U/ml/min) at 55 degrees C and pH 5.5 in 72 h. The result indicates thermophilic mutantT. dupontiihas a potential for industrial use, because enzyme obtained from thermophile is more appropriate for industrial process where high temperature is involved.