自絮凝颗粒酵母乙醇连续发酵耦合废液全循环工艺的研究  

Continuous ethanol fermentation using self-flocculating yeast coupled with directly recycling of waste distillage

作　　者：李宁[1] 葛旭萌[1] 谢健[1] 白凤武[1] 

机构地区：[1]大连理工大学生物科学与工程系,大连116023

出　　处：《生物加工过程》2006年第4期17-20,共4页Chinese Journal of Bioprocess Engineering

基　　金：国家863高科技研究发展计划项目(2002AA647060)

摘　　要：在以CO2为驱动力的单级悬浮床生物反应器中，进行了自絮凝颗粒酵母乙醇连续发酵耦合废液全循环实验研究。以双酶法制备的玉米粉糖化液为底物，系统连续运行了28d，每隔5d将收集到的发酵液集中精馏处理，得到的废糟液直接用于玉米粉调浆制糖。实验数据表明，在稀释率为0．05h^-1条件下，发酵液中乙醇、残还原糖、残总糖质量浓度基本稳定，其平均值为82．97，30．02和40．87g·L^-1。对废液循环工艺过程中，发酵液中的8种高沸点有机酸进行了定量分析，发现发酵液中仅丙酮酸有明显积累，并最终在0．1～0．3mol·L^-1范围内波动。实验结果表明：系统中存在的高沸点副产物不对乙醇发酵产生明显抑制作用，乙醇连续发酵能够在废液全循环条件下良好运行。A fermentation system composed of an CO2-lifted suspended-bed bioreactor was established. Continuous ethanol fermentation by a self-flocculating yeast strain coupled with distillage recycling was run for 28 days using two-stage enzymatic hydrolyte of corn powder as medium. Every five days, all of the backset distillage collected after distilling the final beer was directly used to mix the corn powder. The experimental data revealed that concentrations of ethanol, residual reductive sugar and total residual sugar in the broth were maintained relatively stable with their average levels of 82.97,30.02 and 40.87 g·L^-1, respectively, at the dilution rate of 0.05 h. Concentrations of eight high boiling point organic acids were determined quantitatively by HPLC during the continuous ethanol fermentation with the recycle of distillage. It was found that only pyruvic acid was significantly accumulated and the concentration of pyruvic acid fluctuated in range of 0.1 - 0.3 mol·L^-1, finally. The experimental results revealed that high boiling point organic acids existed in this system exert no significant inhibition on the ethanol fermentation process, and continuous ethanol fermentation can be run well under the conditions of distillage recycling.

关 键 词：自絮凝酵母 乙醇连续发酵 废糟液全循环 高沸点有机酸 

分 类 号：TQ92[轻工技术与工程—发酵工程]