Fed-batch culture strategy for high yield of baker's yeast with high fermentative activity

Based on the determination of the operational conditions for batch culture and fed-batch culture of baker's yeast by process analysis and continuous culture, a correlation, which describes the relationship between fermentative activity (FA) and specific growth rate (mu), was obtained. Combining this correlation and the exponential fed-batch culture equation, a fed-batch culture strategy was developed to obtain high yield and high fermentative activity by controlling mu at different stages. The results showed that when the initial and residual sugar concentrations were controlled to be 15-30 g/L and 3-6 g/L, respectively, different stirring speeds were applied at different stages to provide optimal oxygen transfer conditions. When this proposed fed-batch culture strategy was used in a fed-batch culture, the yield of baker's yeast reached 0.432 g/g with high fermentative activity (1180 ml). Thus, the combined bed-batch culture of baker's yeast with high yield and high fermentative activity was realized.