title: irrE, an exogenous gene from Deinococcus radiodurans, improves the growth of and ethanol production by a Zymomonas mobilis strain under ethanol and acid stress.
abstract: During ethanol fermentation, bacterial strains may encounter various stresses, such as ethanol and acid shock, which adversely affect cell viability and the production of ethanol. Therefore, ethanologenic strains that tolerate abiotic stresses are highly desirable. Bacteria of the genus Deinococcus are extremely resistant to ionizing radiation, ultraviolet light, and desiccation, and therefore constitute an important pool of extreme resistance genes. The irrE gene encodes a general switch responsible for the extreme radioresistance of D. radiodurans. Here, we present evidence that IrrE acting as a global regulator confers high stress tolerance to a Zymomonas mobilis strain. Expression of the gene protected Z. mobilis cells against ethanol, acid, osmotic, and thermal shock. It also markedly improved cell viability, the expression levels and enzyme activities of pyruvate decarboxylase and alcohol dehydrogenase, and the production of ethanol under both ethanol and acid stress. These data suggest that irrE is a potentially promising gene for improving the abiotic stress tolerance of ethanologenic bacterial strains.
authors.affiliation: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ruiqiang
authors.initials: R
authors.lastname: Ma
authors.forename: Zhonglin
authors.initials: Z
authors.lastname: Zhao
authors.forename: Zhengfu
authors.initials: Z
authors.lastname: Zhou
authors.forename: Wei
authors.initials: W
authors.lastname: Lu
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Ming
authors.initials: M
authors.lastname: Chen
mesh_terms: D000426:Alcohol Dehydrogenase / Q000378:metabolism; D002470:Cell Survival / Q000235:genetics; D034301:Deinococcus / Q000235:genetics*; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation / Q000235:genetics*; D010957:Plasmids / Q000235:genetics; D011767:Pyruvate Decarboxylase / Q000378:metabolism; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014170:Transformation, Genetic / Q000235:genetics; D017355:Zymomonas / Q000201:enzymology / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism
chemical_list: D012329:RNA, Bacterial; D000431:Ethanol; D000426:Alcohol Dehydrogenase; D011767:Pyruvate Decarboxylase