Characterization of Dextran Biosynthesized by Glucansucrase from Leuconostoc pseudomesenteroides and Their Potential Biotechnological Applications

Renpeng Du; Liansheng Yu; Meng Sun; Guangbin Ye; Yi Yang; Bosen Zhou; Zhigang Qian; Hongzhi Ling; Jingping Ge

doi:10.3390/antiox12020275

Characterization of Dextran Biosynthesized by Glucansucrase from Leuconostoc pseudomesenteroides and Their Potential Biotechnological Applications

Antioxidants (Basel). 2023 Jan 26;12(2):275. doi: 10.3390/antiox12020275.

Authors

Renpeng Du^{1

2}, Liansheng Yu¹, Meng Sun¹, Guangbin Ye³, Yi Yang¹, Bosen Zhou¹, Zhigang Qian², Hongzhi Ling¹, Jingping Ge¹

Affiliations

¹ Engineering Research Center of Agricultural Microbiology Technology, Ministry of Education & Heilongjiang Provincial Key Laboratory of Plant Genetic Engineering and Biological Fermentation Engineering for Cold Region & Key Laboratory of Microbiology, College of Heilongjiang Province & School of Life Sciences, Heilongjiang University, Harbin 150080, China.
² State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
³ School of Basic Medical Sciences, Youjiang Medical University for Nationalities, Baise 533000, China.

Abstract

Glucansucrase was purified from Leuconostoc pseudomesenteroides. The glucansucrase exhibited maximum activity at pH 5.5 and 30 °C. Ca²⁺ significantly promoted enzyme activity. An exopolysaccharide (EPS) was synthesized by this glucansucrase in vitro and purified. The molecular weight of the EPS was 3.083 × 10⁶ Da. Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy showed that the main structure of glucan was 97.3% α-(1→6)-linked D-glucopyranose units, and α-(1→3) branched chain accounted for 2.7%. Scanning electron microscopy (SEM) observation of dextran showed that its surface was smooth and flaky. Atomic force microscopy (AFM) of dextran revealed a chain-like microstructure with many irregular protuberances in aqueous solution. The results showed that dextran had good thermal stability, water holding capacity, water solubility and emulsifying ability (EA), as well as good antioxidant activity; thus it has broad prospects for development in the fields of food, biomedicine, and medicine.

Keywords: Leuconostoc pseudomesenteroides; characterization; dextran; glucansucrase; in vitro.

Grants and funding

Outstanding Youth Fund Project of Natural Science Foundation of Heilongjiang Province [No. YQ2021C030] (R.D.). Project funded by China Postdoctoral Science Foundation [No. 2022MD713755] (R.D.). Heilongjiang Province Postdoctoral Funding Project [No. LBH-Z21082] (R.D.). Open Funding Project of State Key Laboratory of Microbial Metabolism [No. MMLKF22-07] (R.D.). Promotion Project of Basic Ability for Young and Middle-aged Teachers in Universities of Guangxi [NO. 2022KY0541, 2022KY0547] (G.Y.)