title: Dual utilization of NADPH and NADH cofactors enhances xylitol production in engineered Saccharomyces cerevisiae.
abstract: Xylitol, a natural sweetener, can be produced by hydrogenation of xylose in hemicelluloses. In microbial processes, utilization of only NADPH cofactor limited commercialization of xylitol biosynthesis. To overcome this drawback, Saccharomyces cerevisiae D452-2 was engineered to express two types of xylose reductase (XR) with either NADPH-dependence or NADH-preference. Engineered S. cerevisiae DWM expressing both the XRs exhibited higher xylitol productivity than the yeast strain expressing NADPH-dependent XR only (DWW) in both batch and glucose-limited fed-batch cultures. Furthermore, the coexpression of S. cerevisiae ZWF1 and ACS1 genes in the DWM strain increased intracellular concentrations of NADPH and NADH and improved maximum xylitol productivity by 17%, relative to that for the DWM strain. Finally, the optimized fed-batch fermentation of S. cerevisiae DWM-ZWF1-ACS1 resulted in 196.2 g/L xylitol concentration, 4.27 g/L h productivity and almost the theoretical yield. Expression of the two types of XR utilizing both NADPH and NADH is a promising strategy to meet the industrial demands for microbial xylitol production.
authors.affiliation: Department of Agricultural Biotechnology and Center for Food and Bioconvergence, Seoul National University, Seoul, Republic of Korea.
authors.forename: Jung-Hyun
authors.initials: JH
authors.lastname: Jo
authors.affiliation: Department of Agricultural Biotechnology and Center for Food and Bioconvergence, Seoul National University, Seoul, Republic of Korea.
authors.forename: Sun-Young
authors.initials: SY
authors.lastname: Oh
authors.affiliation: Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, Republic of Korea.
authors.forename: Hyeun-Soo
authors.initials: HS
authors.lastname: Lee
authors.affiliation: Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, Republic of Korea. ycpark@kookmin.ac.kr.
authors.forename: Yong-Cheol
authors.initials: YC
authors.lastname: Park
authors.affiliation: Department of Agricultural Biotechnology and Center for Food and Bioconvergence, Seoul National University, Seoul, Republic of Korea. jhseo94@snu.ac.kr.
authors.forename: Jin-Ho
authors.initials: JH
authors.lastname: Seo
mesh_terms: D000449:Aldehyde Reductase / Q000235:genetics / Q000378:metabolism*; D061249:Batch Cell Culture Techniques; D005285:Fermentation; D060847:Metabolic Engineering; D009243:NAD / Q000378:metabolism*; D009249:NADP / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D014993:Xylitol / Q000096:biosynthesis*
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D009243:NAD; D009249:NADP; D000449:Aldehyde Reductase; D014993:Xylitol
keywords: Cofactor regeneration; Glucose-limited fed-batch fermentation; NADH-preferring xylose reductase; Saccharomyces cerevisiae; Xylitol