BREEDING OF BACTERIAL CELLULOSE-PRODUCING BACTERIA UNDER ARTP MUTATION AND OPTIMIZATION OF FERMENTATION CONDITIONS

Mutagenesis of the target strain Komagataeibacter xylinus was carried out using ARTP mutagenesis technique.The BC high-yield strain,named G31,was selected and its heredity was stable after 10 subcultures.On the basis of single factor experiments,response surface analysis was performed using Plackett-Burman and Central composite design,while BC yield was as the response value.The results showed that the optimum fermentation conditions for the high-yield strain G31 were as follows:the ratio of glucose to mannitol of 1:14 g·(100 mL)^-1,MgSO₄·7H₂O 0.13 g·(100 mL)^-1,and glacial acetic acid 0.25 mL·(100 mL)^-1.Under the optimal fermentation conditions,the BC production value was 8.49 g/L,which had no obvious difference with the predicted value (8.61 g/L).In addition,the BC production of Mutagenesis strain was 2.63 times as much as the initial strain.