Simultaneous enzymatic wheat starch saccharification and fermentation to lactic acid by Lactococcus lactis

Simultaneous saccharification of starch from whole-wheat flour and fermenta tion to lactic acid (SSF) was investigated. For saccharification the commer cial enzyme mixture SAN Super 240 L, having alpha-amylase, amyloglucosidase and protease activity, was used, and Lactococcus lactis ssp. lactis ATCC 1 9435 was used for the fermentation. SSF was studied at flour concentrations corresponding to starch concentrations of 90 g/l and 180 g/l and SAN Super concentrations between 3 mu l/g and 8 mu l/g starch. Kinetic models, devel oped for the saccharification and fermentation, respectively, were used for simulation and data from SSF experiments were used for model verification. The model simulated SSF when sufficient amounts of nutrients were availabl e during fermentation. This was achieved with high wheat hour concentration s or with addition of yeast extract or amino acids. Nutrient release was de pendent on the level of enzyme activity.