高等学校化学学报

高等学校化学学报 ›› 2004, Vol. 25 ›› Issue (7): 1288.

• 研究简报 • 上一篇    下一篇

Enterococcus durans产胞外多糖EPS-Ⅰ的分离纯化和结构分析

顾笑梅1, 吴厚铭2, 马桂荣1   

  1. 1. 山东大学生命科学院微生物技术国家重点实验室, 济南 250100;
    2. 中国科学院上海有机化学研究所生命有机化学国家重点实验室, 上海 200032
  • 收稿日期:2003-05-16 出版日期:2004-07-24 发布日期:2004-07-24
  • 通讯作者: 马桂荣(1938年出生),女,教授,主要从事微生物资源方面的研究.E-mail:grma@beelink.com E-mail:grma@beelink.com

Isolation, Purification and Structural Elucidation of EPS-Ⅰ,an Extracellular Polysaccharide from Enterococcus durans

GU Xiao-Mei1, WU Hou-Ming2, MA Gui-Rong1   

  1. 1. State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, China;
    2. State Key Laboratory of Bioorganic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
  • Received:2003-05-16 Online:2004-07-24 Published:2004-07-24

PDF (PC)

被引次数

21

摘要： 乳酸菌(LAB)作为对人类健康有益的食品级微生物正日益受到国内外科研工作者的关注.乳酸菌所产胞外多糖(EPS)即是LAB在生长代谢过程中分泌到细胞壁外的粘液多糖或荚膜多糖.不同种类的LAB所产的胞外多糖也不同,其结构变化多样,生物活性与其空间结构、分子量、分支度和溶解度有密切关系[1,2].近年来国外有报道分离得到具有抗肿瘤和抗炎活性的乳酸菌EPS-Ⅰ[3,4],但是国内对乳酸菌所产胞外多糖的研究尚未见报道.本实验从鸡肠道中的一株乳酸菌Enterococcus durans的发酵液中分离纯化得到一种具有免疫活性的胞外多糖EPS-Ⅰ[5,6],通过化学和光谱分析证明它是由葡萄糖和甘露糖组成的五糖重复单元聚合的多糖,同时得出EPS2的五糖重复单元结构.

关键词: Enterococcus durans, EPS-Ⅰ, 胞外多糖, 分离纯化

Abstract: The rough crystal of exopolysaccharide produced by Enterococcus durans, a strain of lactic acid bacteria screened from the intestine of a cock in our laboratory, was purified by CM-cellulose column chromatography, DEAE-Sephadex A-25 ionexchange and Sephadex G-100 gel chromatography to give EPS-Ⅰ. The EPS-Ⅰ was eluted as a single peak in HPLC analysis, indicating the homogeneity of EPS-Ⅰ and free from low-molecular-weight polysaccharides. The molecular weight of the EPS-Ⅰ was determined as 42 000 by the light scattering method. The result of its elemental analysis was C 41.08% and H 7.23% without the elements of N, P and S. Monosaccharide analysis showed that it was composed of Glc and Man in a molar ratio of 4∶1. Sugar composition analysis, methylation analysis and 1H and 13C NMR spectroscopy revealed that the EPS-Ⅰ was composed of pentasaccharide repeating units. The sequence of sugar residues was determined by using two-dimensional NMR, including heteronuclear multiple-bond correlation(HMBC) and nuclear overhauser effect spectroscopy(NOESY). The structure of the pentasaccharide repeating unit of EPS-Ⅰ was given, a new excellular polysaccharide from lactic acid bacterium compared with other EPSs was reported.

Key words: Enterococcus durans, EPS-Ⅰ, Extracellular polysaccharide, Purification

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