响应面法优化双频超声波辅助Xanthomonas campestris发酵工艺

Optimization of Dual Frequency Ultrasound Assisted Xanthomonas campestris Fermentation by Response Surface Method

以黄原胶的产量为考察指标,采用单因素试验及响应面法对双频超声波辅助Xanthomonas campestris发酵工艺参数(25和40 kHz超声波工作时间比、介质温度、超声波功率密度、超声波处理时长)进行优化。结果表明,采用双频超声波辅助发酵的最佳工作参数为25 kHz和40 kHz超声波工作时间比25 s∶30 s、介质温度26℃、超声波功率密度72 W/L、超声波处理时间62 min,在30℃条件下振荡发酵72 h,黄原胶的产量为17.5±0.2 g/L,与对照组(9.3±0.3 g/L)相比,黄原胶的产量提高88.2%,表明适当超声波处理可以提高黄原胶产量,能为超声波辅助微生物发酵提供参考依据。

The fermentation process parameters(working time ratio of 25 and 40 kHz ultrasound,medium temperature,ultrasound power density and time)were optimized by single-factor experiment and response surface method.The results showed that the optimum parameters of ultrasound assisted fermentation for Xanthomonas campestris were 25 kHz to 40 kHz working time ratio of 25 s∶30 s,medium temperature of 26℃,power density of 72 W/L and time of 62 min.After that,the fermentation continued at the temperature of 30℃for 72 h,and the yield of xanthan gum reached 17.5±0.2 g/L,which was 88.2%higher than that of the control(9.3±0.3 g/L).The results showed that proper sonication could increase the yield of xanthan gum,which could provide references for ultrasound assisted microbial fermentation.