Optimization and statistical modeling of microbial cellulase production using submerged culture

Abstract

Cellulase is considered to be much important enzyme in organic acid and biotechnology industries. Earlier, we have isolated cellulase producing two different bacterial strains from soils collected from a paper manufacturing plant, Budhar, Central India, and from a grass and forage store present nearby Hotel Radisson Blu, Indore, and after biochemical, physical, and physiological characterization including 16S rRNA sequencing, confirmed as Bacillus licheniformis Bi1 and Ochrobactrum anthropi Oa2, respectively. Here, in this study, we optimized four variables, namely, incubation period, temperature, pH, and inoculum percentage for cellulase production medium to get maximum cellulase production using statistical experimental design, Central Composite Design and further refined using the statistical second order polynomial model, Response Surface Methodology (RSM). Under optimized conditions, cellulase activity produced was 118 ± 12 µM/min/mg and 69.3 ± 8.5 µM/min/mg, respectively, whereas predicted value was 124 µM/min/mg and 82.3 µM/min/mg for B. licheniformis Bi1 and O. anthropi Oa2, respectively. There was 2.5-fold increase in production of cellulase by applying RSM model.