Scale-up production of Bacillus thuringiensis by Box-type solid-state fermentation equipment

摘要

The Bacillus thuringiensis (Bt) which is considered as the most effective bio-pesticide is widely used in the world. There are mainly two modes for the production of this microbial pesticides: submerged fermentation and solid-state fermentation. In this paper, The Scale-up of Kg-class Bt production was studied on wheat bran based media in the Box-type solid-state fermentation equipment made by our lab. The fermentation conditions were optimized and the result show that, Bt production yielded a significant increase in spore count and toxin content at the following conditions: actiactivation of culture for 8h, initial moisture content of solid substrate 55%, pH value 7.5, keeping the thick of inoculated media about 4cm and fermenting for 45 h, Maintaining the temperature within a range of 25-30°C, The bioassay efficacy of the product could be above 13000IU-mg~(-1), The production of Bt kilograms class by solid-state fermentation was successfully represented as well as providing a strong technical support to the large-scale industrial production of Bt bio-pesticide.