pH两阶段控制策略发酵生产重组角质酶

为提高基因工程菌Bacillus subtilis WSHB06-07发酵生产角质酶的产量和生产强度，考察了pH（5.5~8.0）对菌体生长和产酶的影响。基于不同pH发酵过程中菌体比生长速率及比产物合成速率的变化，确定了pH两阶段控制策略，即0~4 h时控制pH 7.5，4 h后将pH调至6.5。通过采用这一优化策略，角质酶酶活有了较大的提高，达170 U/mL，生产强度为16.9 kU/(L·h)，比恒定pH 7.5控制模式下分别提高了122.6%和123.2%。

Studies on Two-stage pH Control Strategy of Recombinant Cutinase Production

To enhance the yield and productivity of cutinase from recombinant Bacillus subtilis WSHB06-07, the effect of pH on cell growth and product formation was investigated. Based on specific cell growth rate and specific cutinase formation rate under different pH condition, a two stage pH control strategy was developed, in which pH was controlled at 7.5 for the first 4h and then shift to 6.5. By the utilization of this strategy, the yield of cutinase was significantly improved, the maximal cutinase activity and the productivity were 170 U/mL and 16.9 kU/(L·h), which were increased by 122.6% and 123.2%, respectively, compared to that from the condition of constant pH 7.5.