OPTIMIZATION OF PROCESS PARAMETERS AND SCALE-UP OF XYLANASE PRODUCTION FROM BACILLUS AMYLOLIQUIFACIENS SH8 IN A STIRRED TANK BIOREACTOR

摘要

Bacillus amyloliquifaciens SH8 has been explored as a potential xylanolytic in-house producer for xylanase production in a bioreactor by optimizing process conditions. The scale-up of the fermentation process up to 3.5 L along with the optimization of physical parameters yielded a significantly increased xylanase yield - of 67.80 IU/mL, in 8 h of fermentation at an inoculum size of 10% with an aeration rate of 1.0 vvm and agitation speed of 300 rpm. The extracellular purified enzyme was found stable at pH6.0 and an optimal temperature of 90 degrees C. Metal ions, such as Zn2+, Ca2+ and Mn2+, increased the residual enzyme activity, whereas Cu2+, Mg2+ and Na2+ strongly inhibited the enzyme activity.