In this study, an in situ 7.5 L ultrasonic fermentation tank was used to culture Saccharomyces cerevisiae at 30°C for 36 hr to explore the effects of low intensity ultrasound on the production of glutathione (GSH). Ultrasonic conditions of 28 kHz frequency, 28 W/L power density for fermentation time of 0–12 hr, 280 W/L power density for fermentation time of 12–36 hr, 3 s of interval and fixed frequency mode were used for the set‐up and a nonsonicated set‐up served as the control for the experiment. Results showed that ultrasound treatment increased total GSH production by 15.60% from a maximum value of 45.52 mg/L in the control to a maximum value of 52.62 mg/L in the sonicated sample. Also, intracellular and extracellular GSH productions in the sonicated sample increased by 5.60% and 42.92% respectively. Regular detection of the changes of biomass yield, residual sugar, dissolved oxygen and pH showed that sonication resulted in biomass increased by 7.25%, glucose consumption rate increased by 53.08% and dissolved oxygen content decreased by 41.67%. The biomass models of sonication and nonsonication treatments were established according to growth of S. cerevisiae showed that the model fitted well with Logistic regression in which the strain specific growth rate increased by 60.95% after sonication. GSH production model agreed with Luedeking‐Piret regression in which GSH synthesis parameters of sonication, α and β increased by 1.96% and 19.64% in comparison to the nonsonicated sample. This study clearly demonstrated that ultrasonic stimulation could improve the biosynthesis of GSH during fermentation.

中文翻译：

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原位低强度超声刺激啤酒酵母的分批发酵以提高谷胱甘肽的产量

在这项研究中，使用原位7.5 L超声波发酵罐培养酿酒酵母在30°C下放置36小时，以探讨低强度超声对谷胱甘肽（GSH）产生的影响。设置超声频率为28 kHz，发酵时间为0–12 hr的功率密度为28 W / L，发酵时间为12–36 hr的功率密度为280 W / L，间隔为3 s，采用固定频率模式-和非超声设置作为实验的对照。结果表明，超声处理使总GSH产量增加了15.60％，从对照组的最大值45.52 mg / L到超声处理样品的最大值52.62 mg / L。而且，超声处理后的样品中细胞内和细胞外GSH的产量分别增加了5.60％和42.92％。定期检测生物量产量，残留糖分，溶解氧和pH的变化表明，超声处理导致生物量增加了7。25％时，葡萄糖消耗率增加了53.08％，溶解氧含量减少了41.67％。建立了超声处理和非超声处理的生物量模型。酿酒酵母表明该模型与Logistic回归拟合得很好，在超声处理后，菌株比生长速率增加了60.95％。GSH生产模型与Luedeking-Piret回归吻合，其中超声处理的GSH合成参数α和β与未超声处理的样品相比分别增加了1.96％和19.64％。这项研究清楚地表明，超声刺激可以改善发酵过程中GSH的生物合成。