Optimization Of Xylanase Production By Bacillus Substilis Using Response Surface Methodology

Abstract

Improved production of enzymes by microorganisms is dependent on various factors including nutritional, physiological parameters besides the biochemical nature of the microbial strain involved. This part of the study emphasizes on optimization of various parameters which could influence the productivity and yield of xylanase enzyme from Bacillus subtilis. An attempt was made to optimize both physical and nutritional parameters which play a major role in enhancing the productivity of the enzyme. Both cultural and medium parameters were optimized to yield highest xylanase production. The variables having the most relevant effect on xylanase yield were identified using a 2-level Plackett-Burman design and their levels were further optimized for enhanced xylanase production by employing a Box-Behnken design. Multiple trials were conducted as suggested by the model and all retrieved data was analysed for variance by ANOVA. The experiment was carried out in triplicate to estimate the experimental errors and to test for lack- of - fit of the data using the second-degree polynomial model. The results of statistical analysis shown that the 95% confidence levels of Xylose, Yeast extract, MgSO4, K2HPO4, KH2PO4, temperature, rpm, incubation time and pH were 5.85, 6.19, 4.61, 0.3819, 0.4212, -5.01, 0.4507, 6.23 and 6.05 respectively, which are considered to significantly influence xylanase production. The Xylanase activity by using all the optimized parameters was 141.23 U/mL.