title: Microbial conversion of ginsenoside Rd from Rb1 by the fungus mutant Aspergillus niger strain TH-10a.
abstract: Ginsenoside Rd, one of the ginsenosides with significant pharmaceutical activities, is getting more and more attractions on its biotransformation. In this study, a novel fungus mutant, the Aspergillus niger strain TH-10a, which can efficiently convert ginsenoside Rd from Rb1, was obtained through screening survival library of LiCl and ultraviolet (UV) irradiation. The transformation product ginsenoside Rd, generated by removing the outer glucose residue from the position C20 of ginsenoside Rb1, was identified through high-performance liquid chromatography (HPLC) analysis. Factors for the microbial culture and biotransformation were investigated in terms of the carbon sources, the nitrogen sources, pH values, and temperatures. This showed that maximum mycelia growth could be obtained at 28°C and pH 6.0 with cellobiose and tryptone as the carbon source and the nitrogen source, respectively. The highest transformation rate (∼86%) has been achieved at 32°C and pH 5.0 with the feeding time of substrate 48 hr. Also, Aspergillus niger strain TH-10a could tolerate even 40 mg/mL ginseng root extract as substrate with 60% bioconversion rate after 72 hr of treatment at the optimal condition. Our results highlight a novel ginsenoside Rd transformation fungus and illuminate its potentially practical application in the pharmaceutical industries.
authors.affiliation: a Jilin Ginseng Academy , Changchun University of Chinese Medicine , Changchun , China.
authors.forename: Li
authors.initials: L
authors.lastname: Feng
authors.affiliation: a Jilin Ginseng Academy , Changchun University of Chinese Medicine , Changchun , China.
authors.forename: Chunchun
authors.initials: C
authors.lastname: Xu
authors.affiliation: b The Affiliated Hospital of Changchun University of Chinese Medicine , Changchun , China.
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Li
authors.affiliation: a Jilin Ginseng Academy , Changchun University of Chinese Medicine , Changchun , China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: a Jilin Ginseng Academy , Changchun University of Chinese Medicine , Changchun , China.
authors.forename: Yulin
authors.initials: Y
authors.lastname: Dai
authors.affiliation: c Jilin Agricultural University , Changchun , China.
authors.forename: Hongxiang
authors.initials: H
authors.lastname: Han
authors.affiliation: a Jilin Ginseng Academy , Changchun University of Chinese Medicine , Changchun , China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Yu
authors.affiliation: a Jilin Ginseng Academy , Changchun University of Chinese Medicine , Changchun , China.|d Changchun Center of Mass Spectrometry , Changchun Institute of Applied Chemistry, Chinese Academy of Science , Changchun , China.
authors.forename: Shuying
authors.initials: S
authors.lastname: Liu
mesh_terms: D001234:Aspergillus niger / Q000235:genetics / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D036145:Ginsenosides / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D009154:Mutation; D010802:Phylogeny; D012335:RNA, Ribosomal / Q000235:genetics; D013696:Temperature
chemical_list: D036145:Ginsenosides; D012335:RNA, Ribosomal; C049863:ginsenoside Rd
keywords: Bioconversion rate; biotransformation; ginseng; ginsenoside