Adaptive Laboratory Evolution for Multistress Tolerance, including Fermentability at High Glucose Concentrations in Thermotolerant Candida tropicalis

Energies

Minenosuke Matsutani¹  Chansom Keo-oudone²  Mingkhuan Chanhming²  Nookhao Vongvilaisak²  Vanhnavong Savanhnaly²  Somchanh Bounphanmy²  Mochamad Nurcholis³  Savitree Limtong⁴  Mamoru Yamada⁵  Tomoyuki Kosaka⁵  Koudkeo Phommachan⁵ 

[1] Department of Biological Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi 753-8515, Japan;Department of Biology, Faculty of Natural Science, National University of Laos, Vientiane 7322, Laos;Department of Food Science and Technology, Faculty of Agricultural Technology, Brawijaya University, Malang 65145, Indonesia;Department of Microbiology, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand;Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi 753-8515, Japan;

关键词: Candida tropicalis;    fermenting yeast;    adaptive laboratory evolution;    fermentability at high glucose concentrations;    multistress tolerance;   

DOI  :  10.3390/en15020561

来源: DOAJ

【 摘 要 】

Candida tropicalis, a xylose-fermenting yeast, has the potential for converting cellulosic biomass to ethanol. Thermotolerant C. tropicalis X-17, which was isolated in Laos, was subjected to repetitive long-term cultivation with a gradual increase in temperature (RLCGT) in the presence of a high concentration of glucose, which exposed cells to various stresses in addition to the high concentration of glucose and high temperatures. The resultant adapted strain demonstrated increased tolerance to ethanol, furfural and hydroxymethylfurfural at high temperatures and displayed improvement in fermentation ability at high glucose concentrations and xylose-fermenting ability. Transcriptome analysis revealed the up-regulation of a gene for a glucose transporter of the major facilitator superfamily and genes for stress response and cell wall proteins. Additionally, hydropathy analysis revealed that three genes for putative membrane proteins with multiple membrane-spanning segments were also up-regulated. From these findings, it can be inferred that the up-regulation of genes, including the gene for a glucose transporter, is responsible for the phenotype of the adaptive strain. This study revealed part of the mechanisms of fermentability at high glucose concentrations in C. tropicalis and the results of this study suggest that RLCGT is an effective procedure for improving multistress tolerance.

【 授权许可】

Unknown