title: Cloning, expression and medium optimization of validamycin glycosyltransferase from Streptomyces hygroscopicus var. jinggangensis for the biotransformation of validoxylamine A to produce validamycin A using free resting cells.
abstract: Validamycin A is widely used to control Basidiomycetes, which causes sheath blight disease in rice, potatoes, vegetables, and other crops as well as dumping-off disease in vegetable seedlings, cotton, sugar beets, and other plants. In order to improve the content of validamycin A in the commercial products, valG from Streptomyces hygroscopicus was successfully cloned into Escherichia coli BL21(DE3) and was directly employed as the biocatalyst in the biotransformation from validoxylamine A to validamycin A with the existence of d-cellobiose using the free resting cells in the present study. The fermentation medium was optimized through single factor experiment and response surface method. With the optimized medium, which contained lactose 4.7g/L, yeast extract 49.5g/L, ammonium chloride 2.7g/L, potassium phosphate buffer solution 110mL/L, Ca(2+) 0.0352g/L, the biomass yield and enzyme activity reached 5.5g/L and 1.49U/mL, respectively, which were nearly twice higher than those with initial medium.
authors: Institute of Fermentation Engineering, College of Biological and Environmental Engineering, Zhejiang University of Technology, 18# Chaowang Road, Hangzhou 310014, PR China.
authors: Yongxian
authors: Y
authors: Fan
authors: Yang
authors: Y
authors: Yu
authors: Xiaoqin
authors: X
authors: Jia
authors: Xiaolong
authors: X
authors: Chen
authors: Yinchu
authors: Y
authors: Shen
mesh_terms: D001711:Biotransformation; D003001:Cloning, Molecular / Q000379:methods*; D003470:Culture Media / Q000737:chemistry / Q000378:metabolism; D004926:Escherichia coli / Q000502:physiology*; D016695:Glycosyltransferases / Q000235:genetics* / Q000378:metabolism; D007294:Inositol / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D013045:Species Specificity; D013302:Streptomyces / Q000145:classification / Q000502:physiology*
chemical_list: D003470:Culture Media; D011994:Recombinant Proteins; C030790:validamycin A; C052534:validoxylamine A; D007294:Inositol; D016695:Glycosyltransferases