COMPARISON AND OPTIMIZATION OF THERMOSTABLE XYLANASES PRODUCTION BY BACILLUS PUMILUS AND BACILLUS CEREUS USING CORN HUSK

Abstract: One of the most studied and widely used commercial Xylanase is endo-1, 4-ß-xylanases.It is useful because the specific activity of Xylanase is higher than the other hydrolytic xylanases. Therefore, xylanases are commonly used in processes involved in degradation of plant materials, paper and pulp bleaching. The present study investigate the production and optimization of thermostable Xylanase by the bacteria Bacillus pumilus (MTCC 10209) and Bacillus cereus (MTCC 10202) under solid state fermentation using corn husk as carbon source since corn husk contain Xylan (28%) and Xylose (17.2%). Maximum production of Xylanase was observed to be 2.2019 (U/ml) and 2.5010 (U/ml) for B.cereus and B.pumilus respectively. The Response Surface Methodology revealed that the optimum temperature, pH and inoculums size for the enzyme activity were 65°C, pH 7.0 and 1 (%v/w) for B.cereus, whereas for B.pumilus it was 65°C, pH 7.0 and 1.50 (%v/w) respectively. The increasing concentration of metal ion (FeSo4) ranging from 1mM-10mM increases the enzyme activity of B.pumilus. Meanwhile, the enzyme activity of B.cereus was strongly inhibited by increasing metal ion concentration.

Keywords: Thermostable Xylanase, solid state fermentation, Bacillus pumilus, Bacillus cereus and response surface methodology.