Industrial manufacturing of bioproducts,especially bioethanol,can benefit from high-temperature fermentation,which requires the use of thermotolerant yeast strains.Mitochondrial activity in yeast is closely related to...Industrial manufacturing of bioproducts,especially bioethanol,can benefit from high-temperature fermentation,which requires the use of thermotolerant yeast strains.Mitochondrial activity in yeast is closely related to its over-all metabolism.However,the mitochondrial respiratory changes in response to adaptive thermotolerance are still poorly understood and have been rarely utilized for developing thermotolerant yeast cell factories.Here,adap-tive evolution and transcriptional sequencing,as well as whole-genome-level gene knockout,were used to obtain a thermotolerant strain of Saccharomyces cerevisiae.Furthermore,thermotolerance and bioethanol production efficiency of the engineered strain were examined.Physiological evaluation showed the boosted fermentation ca-pacity and suppressed mitochondrial respiratory activity in the thermotolerant strain.The improved fermentation produced an increased supply of adenosine triphosphate required for more active energy-consuming pathways.Transcriptome analysis revealed significant changes in the expression of the genes involved in the mitochondrial respiratory chain.Evaluation of mitochondria-associated gene knockout confirmed that ADK1,DOC1,or MET7 were the key factors for the adaptive evolution of thermotolerance in the engineered yeast strain.Intriguingly,overexpression of DOC1 with TEF1 promoter regulation led to a 10.1%increase in ethanol production at 42℃.The relationships between thermotolerance,mitochondrial activity,and respiration were explored,and a ther-motolerant yeast strain was developed by altering the expression of mitochondrial respiration-related genes.This study provides a better understanding on the physiological mechanism of adaptive evolution of thermotolerance in yeast.展开更多
基金supported by the National Key Research and De-velopment Program of China (2021YFC2103300),Research Equipment Program of Chinese Academy of Sciences (YJKYYQ20170023)National Natural Science Foundation of China (32071423,31470214,and 32200067)+1 种基金Natural Science Foundation of Hebei Province (C2020204013)Development Program Projects of Hebei Province (22322905D).
文摘Industrial manufacturing of bioproducts,especially bioethanol,can benefit from high-temperature fermentation,which requires the use of thermotolerant yeast strains.Mitochondrial activity in yeast is closely related to its over-all metabolism.However,the mitochondrial respiratory changes in response to adaptive thermotolerance are still poorly understood and have been rarely utilized for developing thermotolerant yeast cell factories.Here,adap-tive evolution and transcriptional sequencing,as well as whole-genome-level gene knockout,were used to obtain a thermotolerant strain of Saccharomyces cerevisiae.Furthermore,thermotolerance and bioethanol production efficiency of the engineered strain were examined.Physiological evaluation showed the boosted fermentation ca-pacity and suppressed mitochondrial respiratory activity in the thermotolerant strain.The improved fermentation produced an increased supply of adenosine triphosphate required for more active energy-consuming pathways.Transcriptome analysis revealed significant changes in the expression of the genes involved in the mitochondrial respiratory chain.Evaluation of mitochondria-associated gene knockout confirmed that ADK1,DOC1,or MET7 were the key factors for the adaptive evolution of thermotolerance in the engineered yeast strain.Intriguingly,overexpression of DOC1 with TEF1 promoter regulation led to a 10.1%increase in ethanol production at 42℃.The relationships between thermotolerance,mitochondrial activity,and respiration were explored,and a ther-motolerant yeast strain was developed by altering the expression of mitochondrial respiration-related genes.This study provides a better understanding on the physiological mechanism of adaptive evolution of thermotolerance in yeast.
