灵芝胞外多糖分批发酵动力学模型

Kinetic Model for Exopolysaccharides (EPS) of Ganoderma lucidum in Batch Fermentation

利用分批发酵研究了灵芝(Ganoderma lucidum)胞外多糖的合成特性,结果表明Ganodermalucidum多糖合成和菌体生长呈部分生长关联型。菌体干重、胞外多糖分别达到15.56g·L-1、3.02g·L-1,胞外多糖对细胞干重得率系数(Yp/x)为0.19。根据分批发酵试验结果采用Logistic方程、Luedeking-Piret方程和类似Luedeking-Piret方程,得到了描述灵芝生长、胞外多糖以及葡萄糖底物消耗分批发酵动力学模型。同时在初始葡萄糖变化较大范围内,试验数据与模型预测值进行了比较拟合,平均相对误差小于5%,表现出很好的适用性。表明该动力学模型对指导灵芝胞外多糖的发酵生产具有实际意义。

The synthetic characteristic of extracellular polysaccharide （EPS） of Ganoderma lucidum performed in batch fermentation was studied. The result showed that the production EPS was partially growth-associated. The cell dry weight （CDW） and EPS reached 15.56g·L^-1 ,3.02g·L^-1 respectively. The yield of EPS to cell dry weight （ Yp/X）was 0.19. Based on the test result of batch fermentation, a kinetic model was proposed by using the Logistic equation for cell growth, the Luedeking Piret equation for EPS production and the Luedeking-piret-like equation for consumption of glucose as substrate. The calculated results of models were compared satisfactorily with experimental data under various glucose concentrations, the average relative error was no more than 5 % . The kinetic model had practically guiding producing PES in fermentation of Ganoderma lucidum.