A strain of Bacillus licheniformis 8-37-0-1 with high exopolysaccharide (EPS) production ability was isolated and identified based on morphological and physiological characteristics and phylogenetic analysis of 16S rDNA sequences. A new type of EPS was isolated from the strain fermentation broth by enzymolysis, isopropanol precipitation, anion-exchange, and gel-filtration chromatography. The new EPS was determined as homogeneous, with a molecular weight of 28260, as determined by High-Performance Size-Exclusion Chromatography Multi-Angle Laser Light Scattering analysis. Its structural characteristics were investigated and elucidated by methylation analysis, partial acid hydrolysis, gas-liquid chromatography mass spectrometry, Fourier transform infrared, and nuclear magnetic resonance spectroscopy. Based on obtained data, the EPS was found to be a levan containing a (2→6)-linked backbone with a single β-d-fructose at the C-1 position every seven residue, on average, along the main chain. Preliminary in vitro tests revealed that EPS could significantly stimulate the proliferation of spleen lymphocyte.
structure, exopolysaccharide, immunological activity, Bacillus licheniformis 8-37-0-1
NCBI PubMed ID: 20199860Publication DOI: 10.1016/j.biortech.2010.01.151Journal NLM ID: 9889523Publisher: Elsevier
Correspondence: minxiao@sdu.edu.cn
Institutions: National Glycoengineering Research Center, Shandong University, Jinan, China, State Key Laboratory of Microbial Technology, Shandong University, Jinan, China, School of Pharmaceutical Sciences, Shandong University, Jinan, China, School of Life Sciences, Fuyang Teachers College, Fuyang, China
Methods: 13C NMR, 1H NMR, methylation, GLC-MS, NMR-2D, TLC, ELISA, acid hydrolysis, GLC, FTIR, HPSEC-MALLS, UV, extraction, elemental analysis, CC, immunological assays, precipitation, phenol-sulfuric acid assay, derivatization, m-hydroxydiphenyl colorimetric method, Gerwig method, Bradford method
Found