title: Efficient biosynthesis of levan from sucrose by a novel levansucrase from Brenneria goodwinii.
abstract: Levan, a unique homopolysaccharide consisting of fructose residues linked by β-(2, 6) bonds, possess promising physiochemical and physiological properties with numerous potential applications. In this study, a novel levan-producing levansucrase was characterized from Brenneria goodwinii. The polysaccharide produced by the recombinant enzyme from sucrose was structurally determined to be levan-type fructan connected by β-(2, 6) linkages. The optimum pH was measured to be pH 6.0 for both sucrose hydrolysis and transfructosylation. The optimum temperature was 35, 45, and 40°C for transfructosylation, sucrose hydrolysis, and total activity, respectively. Higher sucrose concentration greatly favored to levan biosynthesis. The purified recombinant enzyme produced 185g/L levan from 50% (w/v) sucrose at pH 6.0 and 35°C for 12h. The molecular weight of the produced levan polysaccharide reached 1.3×108Da, which was much higher than the ones produced by many reported levansucrases.
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China.
authors.forename: Shuhuai
authors.initials: S
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China.
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China.
authors.forename: Bo
authors.initials: B
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China; Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi 214122, People's Republic of China. Electronic address: wmmu@jiangnan.edu.cn.
authors.forename: Wanmeng
authors.initials: W
authors.lastname: Mu
mesh_terms: D005630:Fructans / Q000096:biosynthesis*; D020563:Gammaproteobacteria / Q000201:enzymology*; D006602:Hexosyltransferases / Q000378:metabolism*; D008970:Molecular Weight; D013395:Sucrose / Q000378:metabolism*
chemical_list: D005630:Fructans; D013395:Sucrose; D006602:Hexosyltransferases; C021513:levansucrase
keywords: Biosynthesis; Brenneria goodwinii; Fructan; Levan; Levansucrase