Thermotolerant genes essential for survival at a critical high temperature in thermotolerant ethanologenic Zymomonas mobilis TISTR 548

被引：27

作者：

Charoensuk, Kannikar ^{[1
]}

Sakurada, Tomoko ^{[2
]}

Tokiyama, Amina ^{[3
]}

Murata, Masayuki ^{[2
]}

Kosaka, Tomoyuki ^{[2
,3
,4
]}

Thanonkeo, Pornthap ^{[5
]}

Yamada, Mamoru ^{[2
,3
,4
]}

机构：

[1] Rajamangala Univ Technol Tawan Ok, Fac Agroind Technol, Div Prod Dev & Management Technol, Chanthaburi Campus, Chanthaburi 22100, Thailand

[2] Yamaguchi Univ, Grad Sch Sci & Technol Innovat, Life Sci, Ube, Yamaguchi 7558505, Japan

[3] Yamaguchi Univ, Fac Agr, Dept Biol Chem, 1677-1 Yoshida, Yamaguchi 7538515, Japan

[4] Yamaguchi Univ, Res Ctr Thermotolerant Microbial Resources, Yamaguchi 7538315, Japan

[5] Khon Kaen Univ, Fac Technol, Dept Biotechnol, Khon Kaen 40002, Thailand

来源：

BIOTECHNOLOGY FOR BIOFUELS | 2017年 / 10卷

关键词：

Zymomonas mobilis; Ethanologenic microbe; Transposon mutagenesis; Thermotolerant gene; Ethanol-tolerant; ESCHERICHIA-COLI-CELLS; SACCHAROMYCES-CEREVISIAE; LIPOPOLYSACCHARIDE CORE; WINE FERMENTATIONS; TRANSPORT-SYSTEM; GENOME SEQUENCE; ACID BACTERIA; RNA HELICASE; HEAT-SHOCK; PROTEIN;

D O I：

10.1186/s13068-017-0891-0

中图分类号：

Q81 [生物工程学（生物技术）]; Q93 [微生物学];

学科分类号：

071005 ; 0836 ; 090102 ; 100705 ;

摘要：

Background: High-temperature fermentation (HTF) technology is expected to reduce the cost of bioconversion of biomass to fuels or chemicals. For stable HTF, the development of a thermotolerant microbe is indispensable. Elucidation of the molecular mechanism of thermotolerance would enable the thermal stability of microbes to be improved. Results: Thermotolerant genes that are essential for survival at a critical high temperature (CHT) were identified via transposon mutagenesis in ethanologenic, thermotolerant Zymomonas mobilis TISTR 548. Surprisingly, no genes for general heat shock proteins except for degP were included. Cells with transposon insertion in these genes showed a defect in growth at around 39 degrees C but grew normally at 30 degrees C. Of those, more than 60% were found to be sensitive to ethanol at 30 degrees C, indicating that the mechanism of thermotolerance partially overlaps with that of ethanol tolerance in the organism. Products of these genes were classified into nine categories of metabolism, membrane stabilization, transporter, DNA repair, tRNA modification, protein quality control, translation control, cell division, and transcriptional regulation. Conclusions: The thermotolerant genes of Escherichia coli and Acetobacter tropicalis that had been identified can be functionally classified into 9 categories according to the classification of those of Z. mobilis, and the ratio of thermotolerant genes to total genomic genes in Z. mobilis is nearly the same as that in E. coli, though the ratio in A. tropicalis is relatively low. There are 7 conserved thermotolerant genes that are shared by these three or two microbes. These findings suggest that Z. mobilis possesses molecular mechanisms for its survival at a CHT that are similar to those in E. coli and A. tropicalis. The mechanisms may mainly contribute to membrane stabilization, protection and repair of damage of macromolecules and maintenance of cellular metabolism at a CHT. Notably, the contribution of heat shock proteins to such survival seems to be very low.

引用

页数：11

共 77 条

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