INFLUENCE OF GROWTH-FACTOR SUPPLEMENTS ON BUTYRIC-ACID PRODUCTION FROM SUCROSE BY CLOSTRIDIUM-BUTYRICUM

During batch fermentation of sucrose to butyric acid by Clostridium bu tyricum the effect of growth factor sup plementation was determined: a ddition of yeast extract (5 g/L) stimulated most. Using biotin as the sole growth factor, average productivity was definitely lower. Beet mo lasses as a combined source of carbon and growth factor were effective only at a high concentration (150 g/L). The optimal butyric acid prod uction (45 g/L, yield 45 %) was achieved with sucrose concentration of 100 g/L in a medium supplemented with yeast extract (5 g/L). It repre sents an average productivity of 0.90 gL(-1) h(-1) and relative butyri c acid concentration of 91 %.