Optimization of cellulolytic enzyme production by thermophilic fungus Thermoascus aurantiacus using response surface methodology

Abstract

In the present study, thermophilic fungus <em>Thermoascus aurantiacus</em>, a local isolate, was used for production of cellulolytic enzymes using rice straw (RS) as substrate under submerged fermentation using Box-Behnken Design (BBD) of Response Surface Methodology (RSM). Themophilic fungus <em>T. aurantiacus</em> grew very well at 50-55°C temperature. BBD was used to study the influence of process parameters, pH (4-6), temperature (40-60°C) and substrate concentration (2-8 g/L) and their interactive effect on cellulase enzyme production. The R² value 0.94 for Filter paper activity and 0.95 for carboxymethyl cellulase activity indicate that the model is appropriate and replicated to predict the effect of pH, temperature and substrate concentration on both enzyme activities. Under optimized conditions, 6.1 (U/gds) FPase activity and 28.2 (U/gds) CMCase activity was observed.