title: Improved polysaccharide production in a submerged culture of Ganoderma lucidum by the heterologous expression of Vitreoscilla hemoglobin gene.
abstract: Expression of Vitreoscilla hemoglobin (VHb) gene was used to improve polysaccharide production in Ganoderma lucidum. The VHb gene, vgb, under the control of the constitutive glyceraldehyde-3-phosphate dehydrogenase gene promoter was introduced into G. lucidum. The activity of expressed VHb was confirmed by the observation of VHb specific CO-difference spectrum with a maximal absorption at 419 nm for the transformant. The effects of VHb expression on intracellular polysaccharide (IPS) content, extracellular polysaccharide (EPS) production and transcription levels of three genes encoding the enzymes involved in polysaccharide biosynthesis, including phosphoglucomutase (PGM), uridine diphosphate glucose pyrophosphorylase (UGP), and β-1,3-glucan synthase (GLS), were investigated. The maximum IPS content and EPS production in the vgb-bearing G. lucidum were 26.4 mg/100mg dry weight and 0.83 g/L, respectively, which were higher by 30.5% and 88.2% than those of the wild-type strain. The transcription levels of PGM, UGP and GLS were up-regulated by 1.51-, 1.55- and 3.83-fold, respectively, in the vgb-bearing G. lucidum. This work highlights the potential of VHb to enhance G. lucidum polysaccharide production by large scale fermentation.
authors.affiliation: Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China.
authors.forename: Huan-Jun
authors.initials: HJ
authors.lastname: Li
authors.affiliation: Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China.
authors.forename: De-Huai
authors.initials: DH
authors.lastname: Zhang
authors.affiliation: Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China.
authors.forename: Tong-Hui
authors.initials: TH
authors.lastname: Yue
authors.affiliation: Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China.
authors.forename: Lu-Xi
authors.initials: LX
authors.lastname: Jiang
authors.affiliation: Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China.
authors.forename: Xuya
authors.initials: X
authors.lastname: Yu
authors.affiliation: Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhao
authors.affiliation: Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Li
authors.affiliation: Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China. Electronic address: xjuwei@163.com.
authors.forename: Jun-Wei
authors.initials: JW
authors.lastname: Xu
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics*; D018533:Biomass; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D005285:Fermentation; D015966:Gene Expression Regulation, Fungal; D005822:Genetic Vectors; D011134:Polysaccharides / Q000096:biosynthesis*; D060888:Real-Time Polymerase Chain Reaction; D020940:Reishi / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*; D054793:Truncated Hemoglobins / Q000096:biosynthesis* / Q000235:genetics*; D015854:Up-Regulation
chemical_list: D001426:Bacterial Proteins; D018076:DNA, Complementary; D011134:Polysaccharides; D054793:Truncated Hemoglobins; C082613:hemoglobin protein, Vitreoscilla
keywords: Biosynthetic genes; Ganoderma lucidum; Medicinal mushroom fermentation; Polysaccharide production; Vitreoscilla hemoglobin