Optimization of Culture Process Conditions and Feeding Strategy for Keratinase by Recombinant Bacillus subtilis

Abstract:

In order to achieve the high production of keratinase by recombinant Bacillus subtilis WB600, fermentation conditions and feeding strategy were optimized in 3 L fermentor, and a fed-batch fermentation was establishde. The results showed that, using a two-stage pH control strategy in which pH was controlled at 7.0 for the first 4 h and then 8.0 for remaining time and a mixed feeding strategy in which keeping the exponential feeding from 6 h to 15 h(6~11 h μ was 0.15 h-1, 11~15 h μ was 0.1 h-1) and then constant-fed fermentation for remaining time, the keratinase activity reached 864 U/mL. The keratinase activity reached a leading level at home, and the keratinase reached 2 900 U/mL overseas.This work reached a high keratinase productivity and it is a stable theroret-ics for the fermention sacle-up process of keratinase.