Screening and Conditions Optimization of Vitamin C Bi-Step Fermentation by Neo-Combination Strain System B_(15-14)

A neo-combination strain system for bi-step vitamin C fermentation was screened,and the effects of environmental factors on the system were studied.The results showed that the most suitable substrate sugar concentration was 7%,under temperature 29~33 ℃,and 31 ℃ was the most suitable.And properly increase aeration volume(20~30 mL filled in 250 mL flask) was conducive to acid production with starting pH at 6.0~7.5.With Bacillus thuringiensis(Bt) as associated strain the fermentation ended within 40 hours,obviously shortened the fermentation time.