黑曲霉产糖化酶黑箱模型的构建和应用

Construction and application of black-box model for glucoamylase production by Aspergillus niger

摘要:

利用碳限制恒化实验研究了黑曲霉生长和糖化酶生产之间的相关性，结果表明当比生长速率低于0.068 h–1时，菌体生长与产酶是相关的，当比生长速率大于0.068 h–1时，菌体生长与产酶不相关。根据恒化实验结果获得黑曲霉葡萄糖底物消耗的Monod动力学模型，并结合葡萄糖和氧消耗的Herbert-Pirt方程和产物形成的Luedeking-Piret方程构建黑曲霉产糖化酶的黑箱模型。应用该模型设计指数补料分批发酵实验控制菌体比生长速率在0.05 h–1，使糖化酶的得率最高达到0.127 g糖化酶/g葡萄糖，并成功地使用模型描述了黑曲霉产糖化酶的发酵过程。实验值和模拟值进行比较表现出很好的适用性，表明黑箱模型可以用于指导黑曲霉产糖化酶发酵过程的设计和优化。

Abstract:

Carbon-limited continuous culture was used to study the relationship between the growth of Aspergillus niger and the production of glucoamylase. The result showed that when the specific growth rate was lower than 0.068 h–1, the production of glucoamylase was growth-associated, when the specific growth rate was higher than 0.068 h–1, the production of glucoamylase was not growth-associated. Based on the result of continuous culture, the Monod dynamics model of glucose consumption of A. niger was constructed, Combining Herbert-Pirt equation of glucose and oxygen consumption with Luedeking-Piret equation of enzyme production, the black-box model of Aspergillus niger for enzyme production was established. The exponential fed-batch culture was designed to control the specific growth rate at 0.05 h–1 by using this model and the highest yield for glucoamylase production by A. niger reached 0.127 g glucoamylase/g glucose. The black-box model constructed in this study successfully described the glucoamylase production by A. niger and the result of the model fitted the measured value well. The black-box model could guide the design and optimization of glucoamylase production by A. niger.