甜高粱茎秆汁液固定化酵母酒精发酵的研究

Ethanol fermentation of sweet sorghum stalk juice by immobilized yeast

本文应用一元线性回归分析法得出了甜高粱茎秆汁液锤度和可溶性总糖含量之间的关系。以甜高粱茎秆汁液为原料，在摇床及流化床反应器上进行了固定化酵母酒精发酵的试验研究。结果表明，以沈农甜杂2号甜高粱为原料，在摇床上作营养盐配比的正交试验，试验得出对提高酒精得率影响因素的主次顺序为：（NH4）2SO4，K2HPO4，MgSO4。最优组合为：0．125％K2HPO4，0．200％（NH4）2SO4．0．050％MgSO4。加营养盐的酒精得率比不加任何营养盐的酒精得率可提高4．0％～8．0％。K2HPO4，（NH4）2SO4的配比对试验结果影响极显著，MgSO4的配比对试验结果影响显著。在流化床反应器上试验，4种较优营养盐组合酒精得率近乎相等，比不加营养盐空白试验酒精得率高。从降低成本角度来讲，选择0．125％K2HPO4，0．200％（NH4）2S4，0．010％MgSO4作为投产试验。本文为燃料乙醇的发展提供了科学的依据。

The relationship between the Brix and the total soluble sugar content of sweet sorghum stalk juice was determined through one-dimensional linear regression. Meanwhile, ethanol fermentation experiments were conducted in a shaking flask and a 10 L fluidized bed bioreactor with stalk juice of SNTZ No. 2 sweet sorghum variety when immobilized yeast was applied. The experimental results in the shaking flask showed that the influence sequence to improve ethanol yield was （NH4）2SO4, MgSO4, K2HPO4, and the optimum ratios of KzHPO4, （NH4）2SO4 and MgSO4 were 0. 125%, 0. 200% and 0. 0505, respectively. Ethanol yields with inorganic salts were increased by 4.0% -8.05 compared to without one. K2HPO4 and （NH4）2SO4 were greatly significant to the experiment results, and MgSO4 ranked second. The experimental results in the fluidized bed bioreactor showed that ethanol yields were nearly equal to four kinds of ideal inorganic salts. And the ethanol yields with inorganic salts were higher than that without one. It was beneficial for ethanol production when blending ratios of K2HPO4, （NH4）2SO4 and MgSO4 were 0. 125%, 0. 200% and 0. 010%, respectively from the aspect of reducing cost. The research provides a scientific basis for fuel ethanol development.