Optimization of process parameters for xylanase production by Bacillus sp. in submerged fermentation

In this study an attempt was made to optimize the cultural and nutritional conditions for xylanase production by Bacillus species in submerge fermentation process. Whole fermentation process was carried out in 250 ml Erlenmeyer flask with agitation speed of 140 rpm. Bacillus subtilis exhibit maximum xylanase production at initial medium pH of 8, substrate concentration of 2% with inoculum size of 2% at 35 degrees C for 48 h of fermentation period. Further supplementation of sucrose, (NH4)(2)SO4 and peptone as a carbon and nitrogen sources favored enzyme production. The other strain Bacillus megaterium showed its peak xylanase production at initial medium pH of 8, inoculum size of 1.5% with substrate concentration of 1.5% at incubation temperature of 40 degrees C for 72 h of fermentation period. The best carbon and nitrogen sources are xylose, KNO3 and malt extract. Both strains can also utilize molasses at 0.5% concentration for xylanase production can grow in medium containing 0.2% NaCl (B. subtilis BS04) and 0.8% NaCl (B. megaterium BM07) respectively. The optimum temperature of xylanase was 50 degrees C and pH was 5 and 5.5 by B. subtilis BS04 and B. megaterium BM07 respectively. Copyright (C) 2015, The Egyptian Society of Radiation Sciences and Applications. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).