分段控温黄原胶发酵过程

XANTHAN FERMENTATION PROCESS VIA TWO-STAGE TEMPERATURE CONTROL

温度是影响黄原胶发酵的重要因素之一。为了优化黄原胶发酵过程的温度控制,在5 L通气式搅拌发酵罐中,非溶氧限制的条件下,对恒温黄原胶发酵过程进行了研究。结果显示,发酵温度为28℃时,在发酵稳定期有较高的菌体浓度,所得黄原胶的丙酮酸含量与表观粘度较高,但有较长的发酵周期。而发酵温度为33℃时,有较短的发酵周期,在发酵稳定期有较高的比产胶速率,但所得黄原胶的丙酮酸含量与表观粘度较低。实验测定了控制黄原胶发酵生长期温度为28℃,稳定期温度为33℃的发酵过程数据。结果表明,与恒温发酵过程相比,通过温度的分段控制可以缩短发酵周期,提高产胶浓度及改善胶的品质,分段控温是黄原胶发酵的一种方便有效的调节手段。

Temperature is one of the most important operational parameters that affect xanthan fermentation process. In order to optimize the temperature control for xanthan fermentation process, the constant temperature xanthan fermentation process was investigated in a 5 L stirred aerated fermenter without dissolved-oxygen limitation. The results show that when the fermentation temperature is 28°C, it has higher bacteria concentration at stationary phase and xanthan gum has higher pyruvate content and superficial viscosity, but it has longer fermentation time. However, when the fermentation is carried out at 33°C, it has higher specific xanthan gum product rate at stationary phase and shorter fermentation time, but xanthan gum has lower pyruvate content and superficial viscosity. The xanthan fermentation process was examined by controlling the temperature at 28°C during growth phase and 33°C during stationary phase. The experimental data shows that compared with constant fermentation process, the two-stage temperature control fermentation process can reduce the fermentation time and increase the final xanthan gum concentration and improve the xanthan gum quality. Two-stage temperature control is a simple and efficient control method to improve xanthan fermentation process.