title: Xylose fermentation efficiency and inhibitor tolerance of the recombinant industrial Saccharomyces cerevisiae strain NAPX37.
abstract: Industrial yeast strains with good xylose fermentation ability and inhibitor tolerance are important for economical lignocellulosic bioethanol production. The flocculating industrial Saccharomyces cerevisiae strain NAPX37, harboring the xylose reductase-xylitol dehydrogenase (XR-XDH)-based xylose metabolic pathway, displayed efficient xylose fermentation during batch and continuous fermentation. During batch fermentation, the xylose consumption rates at the first 36 h were similar (1.37 g/L/h) when the initial xylose concentrations were 50 and 75 g/L, indicating that xylose fermentation was not inhibited even when the xylose concentration was as high as 75 g/L. The presence of glucose, at concentrations of up to 25 g/L, did not affect xylose consumption rate at the first 36 h. Strain NAPX37 showed stable xylose fermentation capacity during continuous ethanol fermentation using xylose as the sole sugar, for almost 1 year. Fermentation remained stable at a dilution rate of 0.05/h, even though the xylose concentration in the feed was as high as 100 g/L. Aeration rate, xylose concentration, and MgSO4 concentration were found to affect xylose consumption and ethanol yield. When the xylose concentration in the feed was 75 g/L, a high xylose consumption rate of 6.62 g/L/h and an ethanol yield of 0.394 were achieved under an aeration rate of 0.1 vvm, dilution rate of 0.1/h, and 5 mM MgSO4. In addition, strain NAPX37 exhibited good tolerance to inhibitors such as weak acids, furans, and phenolics during xylose fermentation. These findings indicate that strain NAPX37 is a promising candidate for application in the industrial production of lignocellulosic bioethanol.
authors.affiliation: College of Architecture and Environment, Sichuan University, No. 24, South Section 1, First Ring Road, Chengdu, Sichuan, 610065, China.|College of Light Industry, Textile and Food Engineering, Sichuan University, No. 24, South Section 1, First Ring Road, Chengdu, Sichuan, 610065, China.
authors.forename: Yun-Cheng
authors.initials: YC
authors.lastname: Li
authors.affiliation: Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto, 860-0862, Japan.
authors.forename: Kanako
authors.initials: K
authors.lastname: Mitsumasu
authors.affiliation: College of Architecture and Environment, Sichuan University, No. 24, South Section 1, First Ring Road, Chengdu, Sichuan, 610065, China.
authors.forename: Zi-Xi
authors.initials: ZX
authors.lastname: Gou
authors.affiliation: College of Architecture and Environment, Sichuan University, No. 24, South Section 1, First Ring Road, Chengdu, Sichuan, 610065, China.
authors.forename: Min
authors.initials: M
authors.lastname: Gou
authors.affiliation: College of Architecture and Environment, Sichuan University, No. 24, South Section 1, First Ring Road, Chengdu, Sichuan, 610065, China. tangyq@scu.edu.cn.
authors.forename: Yue-Qin
authors.initials: YQ
authors.lastname: Tang
authors.affiliation: College of Light Industry, Textile and Food Engineering, Sichuan University, No. 24, South Section 1, First Ring Road, Chengdu, Sichuan, 610065, China.
authors.forename: Guo-Ying
authors.initials: GY
authors.lastname: Li
authors.affiliation: College of Engineering, Peking University, Beijing, 100871, China.
authors.forename: Xiao-Lei
authors.initials: XL
authors.lastname: Wu
authors.affiliation: Department of Applied Microbial Technology, Sojo University, 4-22-1 Ikeda, Nishi-ku, Kumamoto, 860-0082, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Akamatsu
authors.affiliation: Department of Applied Microbial Technology, Sojo University, 4-22-1 Ikeda, Nishi-ku, Kumamoto, 860-0082, Japan.
authors.forename: Hisataka
authors.initials: H
authors.lastname: Taguchi
authors.affiliation: College of Architecture and Environment, Sichuan University, No. 24, South Section 1, First Ring Road, Chengdu, Sichuan, 610065, China.
authors.forename: Kenji
authors.initials: K
authors.lastname: Kida
mesh_terms: D000449:Aldehyde Reductase / Q000235:genetics / Q000378:metabolism; D000431:Ethanol / Q000378:metabolism; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D007218:Industrial Microbiology; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D014994:Xylose / Q000378:metabolism*
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D000431:Ethanol; D014994:Xylose; D000449:Aldehyde Reductase; D005947:Glucose
keywords: Batch fermentation; Continuous fermentation; Industrial Saccharomyces cerevisiae; Inhibitor tolerance; Lignocellulosic bioethanol; Xylose fermentation