中山大学学报自然科学版 ›› 2016, Vol. 55 ›› Issue (6): 125-131.

• 研究论文 • 上一篇    下一篇

Ca2+对希瓦氏菌MR-1胞外多糖的影响

唐连凤1, 周丽华1, 孙丽华1, 宋少云2   

  1. 1. 广东工业大学轻工化工学院, 广东 广州 510006;
    2. 中山大学生命科学学院,广东 广州 510275
  • 收稿日期:2016-03-16 出版日期:2016-11-25 发布日期:2016-11-25
  • 通讯作者: 周丽华;E-mail:qhzhoulh@gdut.edu.cn

Effect of Ca2+ on the extracellular polysaccharide of Shewanella oneidensis MR-1

TANG Lianfeng1, ZHOU Lihua1, SUN Lihua1,SONG Shaoyun2   

  1. 1. School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China;
    2.School of Life Sciences,Sun Yat-sen University,Guangzhou 510275,China
  • Received:2016-03-16 Online:2016-11-25 Published:2016-11-25

摘要:

希瓦氏菌是一类革兰氏阴性土壤铁还原菌,具有胞外电子传递能力,其胞外聚合物的组成是直接影响其电子传递效应的重要因素之一。胞外多糖(EPS)是胞外聚合物的重要组成成分,该文以Shewanella oneidensis MR-1为对象,采用苯酚-硫酸法结合光谱法、色谱法及质谱法等系统地研究了含不同浓度(0、0.7、1.4、2.1和5.0 mmol/L)CaCl2培养基对MR-1胞外多糖的影响。结果表明,不同浓度Ca2+影响下的MR-1多糖的分泌量各不相同,其中Ca2+浓度为21 mmol/L时,MR-1分泌多糖质量浓度最高,为0.3 g/mL,是无Ca2+影响的EPS分泌量的5倍;而Ca2+浓度为1.4 mmol/L 时,EPS为0.08 g/mL,与无Ca2+影响时EPS分泌量相近;Ca2+对MR-1分泌的EPS结构没有显著性影响,获得的EPS均为由α-D-吡喃甘露糖通过 1,3-苷键形成的多糖。研究结果为深入研究希瓦氏菌胞外聚合物提供数据参考。

关键词: Shewanella oneidensis MR-1, 钙离子, 胞外多糖, 甘露糖

Abstract:

Shewanella is a gram-negative soil iron reducing bacteria, which has extracellular electron transfer ability. The composition of the extracellular polymer is one of the important factors that can directly influence the electron transfer effect. Extracellular polysaccharide (EPS) is an important component of extracellular polymers. The effect of different concentrations of CaCl2 (0, 0.7,1.4, 2.1 and 5.0 mmol/L) on the EPS of Shewanella oneidensis MR-1 was herein studied by phenol sulfuric acid method combined with spectrophotometry, chromatography and mass spectrometry. The results showed that the amount of EPS would vary with the Ca2+  concentration. Maximum EPS production of 0.3 g /mL was obtained in the culture medium with 2.1 mmol/L of Ca2+ concentration, which was 5 times greater than that obtained without Ca2+ . The amount of EPS obtained with 1.4 mmol/L Ca2+ concentration was 0.08 g/mL, which was nearly the same to that obtained without Ca2+ . The concentration of Ca2+ in the medium did not significantly influence the structure of EPS produced by MR-1. EPS had a repeating unit with a [→3)-α-D-Manp(1→] backbone chain. The results of this study provide reference data for the further study of Shewanella extracellular polymers.

Key words: Shewanella oneidensis MR-1, exopolysaccharides, Ca 2+; mannose

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