THE STIMULATING EFFECT OF ULTRASOUND ON THE TECHNOLOGICAL QUALITIES OF THE SACCHAROMYCES CEREVISIAE

摘要

The yeast cells Saccharomyces cerevisiae 1% suspensions were irradiated in a bioreactor, by a magnetostrictive method, with ferrite transducers. When the ultrasonic frequency and intensity were 17.3 KHz and 3.8 W.cm~(-2) respectively, and the treatment time was 10 min, the best number (8×10~(10) cell. ml~(-1)) of the viable cells, after 22h in the agitation machine and the small activation energy (9.191 Kcal.mol~(-1)) in multiplying process were obtained. For the same conditions of irradiation, the CO_2 mass release in the fermentation process was greater (for 6% zaharosc in medium-38.75 g.l~(-1)) after 24h in the thermostat. For the control sample, following results are noticed: 9×10~8 cell, ml~(-1) (after 22h) and 12.557 Kcal.mol~(-1) in the multiplying process and 37.5 g.l~(-1) (after 48h) in the fermentation process.