Fermentation Characteristics of Different Strains of Bacillus coagulans with Single and Mixed Carbon Sources

The substrate utilization and metabolism of Bacillus coagulans BH1,HL5 and 36D1 by using various substrates as sole carbon sources,including xylose,trehalose,glucose,isomaltose,sucrose and maltose,and glucose with five above carbon sources as mixed carbon sources were studied. Then,the fermentation characteristics for the three strains in a 5 L tank using glucose and isomaltose as a mixed carbon source were inspected. The fermentation characteristics of the three strains were further investigated in order to determine one strain as the starting strain for subsequent screening of high-efficiency lactic acid fermentation strains. Results showed that that:Under single carbon source fermentation,B.coagulans 36D1 could fully utilize xylose,trehalose and glucose,while BH1 and HL5 had almost no use of xylose and trehalose,and all three strains had no obvious use of sucrose. Under mixed carbon source fermentation,B. coagulans 36D1 exhibited the obvious glucose repressive effect in the fermentation process,and the use of other sugars(especially maltose or isomaltose)by BH1 and HL5 was hardly affected. The results of 5 L tank fermentation showed that B. coagulans HL5 had better utilization of isomaltose. In conclusion,B. coagulans HL5 had a high utilization capacity for maltose,isomaltose and glucose,and would be finalized as the starting strain for subsequent strain screening.