title: Bioconversion of D-glucose to D-psicose with immobilized D-xylose isomerase and D-psicose 3-epimerase on Saccharomyces cerevisiae spores.
abstract: Saccharomyces cerevisiae spores are dormant cells, which can tolerate various types of environmental stress. In our previous work, we successfully developed biological and chemical methods for enzyme immobilization based on the structures of S. cerevisiae spore wall. In this study, we employed biological and chemical approaches for the immobilization of D-xylose isomerase (XI) from Thermus thermophilus and D-psicose 3-epimerase (DPEase) from Agrobacterium tumefaciens with yeast spores, respectively. The enzymatic properties of both immobilized XI and DPEase were characterized and the immobilized enzymes exhibit higher thermostability, broader pH tolerance, and good repeatability compared with free enzymes. Furthermore, we established a two-step approach for the bioconversion of D-glucose to D-psicose using immobilized enzymes. To improve the conversion yield, a multi-pot strategy was adopted for D-psicose production by repeating the two-step process continually. As a result, the yield of D-psicose was obviously improved and the highest yield reached about 12.0 %.
authors.affiliation: Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
authors.forename: Zijie
authors.initials: Z
authors.lastname: Li
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.forename: Shenglin
authors.initials: S
authors.lastname: Duan
authors.forename: Jia
authors.initials: J
authors.lastname: Liu
authors.forename: Peng
authors.initials: P
authors.lastname: Yuan
authors.forename: Hideki
authors.initials: H
authors.lastname: Nakanishi
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Gao
mesh_terms: D016960:Agrobacterium tumefaciens / Q000201:enzymology; D019747:Aldose-Ketose Isomerases / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism; D002238:Carbohydrate Epimerases / Q000378:metabolism*; D004800:Enzymes, Immobilized / Q000378:metabolism; D005632:Fructose / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D013172:Spores, Fungal / Q000378:metabolism; D016963:Thermus thermophilus / Q000201:enzymology
chemical_list: D001426:Bacterial Proteins; D004800:Enzymes, Immobilized; C003243:psicose; D005632:Fructose; D002238:Carbohydrate Epimerases; D019747:Aldose-Ketose Isomerases; C023298:xylose isomerase; D005947:Glucose