超高浓度乙醇连续发酵体系振荡行为诱发因素研究  

Research on triggering factors of oscillatory behavior during continuous VHG ethanol fermentation

作　　者：谭慧萍 王惠国[1] 王林会 赵增彤 程杨好 刘晨光 王亮[3] 李倩[1] TAN Huiping;WANG Huiguo;WANG Linhui;ZHAO Zengtong;CHENG Yanghao;LIU Chenguang;WANG Liang;LI Qian(School of Life Sciences and Biotechnology, Dalian University, Dalian 116622;Dalian SEM Bio-Engineering Technology Company, Dalian 116620;School of Biological Engineering, Dalian Polytechnic University, Dalian 116034;State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240)

机构地区：[1]大连大学生命科学与技术学院,辽宁大连116622 [2]大连赛姆生物工程技术有限公司,辽宁大连116620 [3]大连工业大学生物工程学院,辽宁大连116034 [4]微生物代谢国家重点实验室上海交通大学生命科学与技术学院,上海200240

出　　处：《工业微生物》2022年第2期9-16,共8页Industrial Microbiology

基　　金：国家自然科学基金计划(No.31500040);微生物代谢国家重点实验室开放课题(No.MMLKF20-09);辽宁省教育厅科研项目(No.J2020099);大连市青年科技之星项目(No.2019RQ104)资助。

摘　　要：超高浓度(Very high gravity,VHG)发酵可以显著提高发酵终点乙醇浓度,节省精馏能耗,同时减少废糟液量。然而,酿酒酵母(Saccharomyces cerevisiae)VHG乙醇连续发酵过程中生物量、乙醇、残糖浓度等发酵参数呈现长周期、大振幅的振荡行为,不仅严重影响系统的乙醇发酵性能,而且不利于下游精馏装置的稳定运行。本研究比较三株不同乙醇耐受性的酵母菌株的VHG乙醇连续发酵行为,发现乙醇耐受性强的S.cerevisiae BHL01和S.cerevisiae 4126体系呈现周期性振荡行为,而乙醇耐受性差的S.cerevisiae S288c体系则未观察到振荡行为。此外,通过对低糖稳态体系外源施加乙醇胁迫发现,细胞耐受范围内的外源乙醇胁迫可以诱发周期性的振荡行为。另一方面,本研究考察了培养基组成和供氧对周期性VHG振荡行为的影响,结果表明,切换合成培养基或停止供氧后,振荡行为逐渐衰减,表明周期性VHG振荡行为需要能量和营养维持。综合实验结果,本研究提出VHG振荡行为是比生长速率、比死亡速率、稀释速率和细胞乙醇耐受性整体调控的结果。Very-high-gravity(VHG)fermentation can significantly increase the ethanol concentration at the end point of fermentation,save energy consumption of ethanol distillation and reduce stillage discharge at the same time.However,during the continuous VHG ethanol fermentation by Saccharomyces cerevisiae,the fermentation parameters such as biomass,ethanol and residual glucose concentrations show long-period and large-amplitude oscillation behavior,which not only seriously affect the ethanol fermentation performance of the system,but also is not conducive to the stable operation of the downstream distillation unit.In this study,the continuous VHG ethanol fermentation behaviors of three yeast strains with differential ethanol tolerance were compared.It was found that the systems of S.cerevisiae BHL01 and S.cerevisiae 4126 with strong ethanol tolerance showed periodic oscillatory behavior,while the S.cerevisiae S288c system with poor ethanol tolerance did not observe the oscillatory behavior.Besides,it was found that exogenous ethanol stress within a durable extent for yeast cells during low-gravity continuous ethanol fermentation could efficiently trigger sustained oscillatory behavior.On the other hand,the effects of medium composition and oxygen supply on periodic VHG oscillation behavior were investigated.The results showed that the oscillation behavior gradually attenuated after switching synthetic medium or stopping oxygen supply,indicating that periodic VHG oscillation behavior needed energy and nutrition to maintain.These experimental results demonstrated that VHG oscillation was comprehensively regulated by specific growth rate,specific death rate,dilution rate and cellular ethanol tolerance.

关 键 词：酿酒酵母 超高浓度 振荡行为 乙醇耐受性 

分 类 号：TS2[轻工技术与工程—食品科学与工程]