Optimation of Fermentation Conditions of Amylase by Bacillus subtilis

Singal factor and orthogonal analysis were applied to obtain the optimal conditions for fermenting α-amylase by Bacillus subtilis in liquid culture medium.Five factors,carbon source,nitrogen source,original pH,incubation time and inoculum size were tested respectively;and based on these single factor tests,the carbon concentration,nitrogen concentration,original pH value and inoculum size were analyzed in L9(34) orthogonal analysis.The result showed that the optimal carbon source and nitrogen source were glucose and carbamide,respectively.The optimal incubation time was 30 h.The optimal parameter was original pH value,5.0;carbon concentration,0.2%;nitrogen concentration,1.5%;and inoculum size,2.5%.