LACTIC-ACID FERMENTATION ON BARLEY FLOUR WITHOUT ADDITIONAL NUTRIENTS

An amylolytic lactic acid producing Lactobacillus amylovorus produced 36 g/l of lactic acid in mixed cultures with L. casei without additional nutrients at 37 degrees C in 48 h, when barley flour concentration was 180 g/l (appr. 108 g/l starch) and barley malt quantity 0.8% of flour weight. This represented an improvement of up to 20% in comparison to the fermentation with L. amylovorus or L. casei alone. By simultaneous glucoamylase addition lactic acid production yield was about doubled. With L. casei the lactic acid yield was from 580 g in 72 h to 667 g in 144 h per kg barley flour.