废液全循环工艺中有机酸积累对自絮凝颗粒酵母酒精连续发酵影响的研究

【作者】 孜力汗；

【导师】 白凤武；

【作者基本信息】 大连理工大学 ， 生物化工， 2002， 硕士

【摘要】 在对酵母细胞酒精发酵代谢途径进行分析的基础上，运用离子对色谱法对自絮凝颗粒酵母SPSC01发酵液酒精精馏后的废液中可能存在的高沸点副产物有机酸进行了分析，初步鉴定出了其中的延胡索酸、苹果酸、乳酸和柠檬酸。进而，通过向培养基中添加不同浓度外源有机酸，考察了这些副产物有机酸对自絮凝颗粒酵母生长和酒精发酵的影响，获得了对自絮凝颗粒酵母生长和酒精发酵产生抑制的临界浓度，从动力学角度进行了定量描述，获得了如下体现高沸点副产物有机酸抑制的酒精发酵动力学表达式： 论文最后针对自絮凝颗粒酵母酒精连续发酵耦合废液直接循环使用的工艺流程特点，建立了以虚拟循环批次作为模型参数来预测废液直接循环使用过程高沸点副产物积累规律的数学模型，通过物料衡算，预测了具有代表性有机酸苹果酸的稳态平衡浓度，并与实验测定值进行了比较。这一模型化方法对系统分析自絮凝颗粒酵母酒精连续发酵耦合废液直接循环使用系统其他副产物的积累规律及这些副产物对自絮凝颗粒酵母细胞生长和产物酒精生物合成的影响具有普遍意义。更多还原

【Abstract】 Based on the analysis of ethanol fermentation metabolic pathways, several high boiling point by-products contained within the waste distillage discharged from continuous ethanol fermentation process using self-flocculating yeast strain SPSC01, including fumaric acid, malate, lactic acid and critic acid, were separated by HPLC. Furthermore, the effects of these organic acids on self-flocculating yeast cell growth and ethanol fermentation were investigated through adding these organic acids into the ethanol fermentation system, and the inhibition ethanol fermentation kinetics for self-flocculating yeast cell particles was developed as below.Finally, a theoretical model which can be used to predict the accumulation of all kinds of by-product for self-flocculation yeast cell ethanol fermentation process coupled with directly recycling use of waste distillage was proposed. The model parameter, waste distillage recycling times, can be deduced from experimental data. Malate, as demonstrated by-product, its steady-state concentration accumulated within the ethanol fermentation process was calculated and compared with its critical concentration which exerts obvious inhibition on self-flocculating yeast cell particle growth and ethanol fermentation. It was found that the inhibition of malate on self-flocculating yeast cell particle and ethanol fermentation was negligible.更多还原