The role of extracellular polysaccharides produced by the terrestrial cyanobacterium Nostoc sp. strain HK-01 in NaCl tolerance
The role of extracellular polysaccharides produced by the terrestrial cyanobacterium Nostoc sp. strain HK-01 in NaCl tolerance
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DOI：
10.1007/s10811-011-9672-5
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发表时间：
2011-04
影响因子：
3.3
通讯作者：
Hidehisa Yoshimura;Toshihisa Kotake;Tsutomu Aohara;Y. Tsumuraya;M. Ikeuchi;M. Ohmori
中科院分区：
文献类型：
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作者：
Hidehisa Yoshimura;Toshihisa Kotake;Tsutomu Aohara;Y. Tsumuraya;M. Ikeuchi;M. Ohmori
陆生蓝藻念珠菌。 HK-01比水生蓝藻Anabaenasp更能耐受氯化钠胁迫。 PCC 7120（也称为发菜。PCC 7120）与发菜相似。 HK-01 的系统发育。我们测定了使用或不使用 200 mM NaCl 培养的两种菌株的细胞中胞外多糖（荚膜和释放的多糖）的量。在NaCl胁迫下，发菜HK-01的荚膜多糖含量达到干重的约65％，而AnabaenaPCC 7120的荚膜多糖仅占干重的约18％。当两种发菜HK-01的多糖添加到培养物中时，AnabaenaPCC 7120在NaCl胁迫下生长良好。然而，当添加两种多糖时，AnabaenaPCC 7120在NaCl胁迫下几乎不生长。与鱼腥藻PCC 7120相比，发菜HK-01胞外多糖含有丰富的岩藻糖和葡萄糖醛酸。在NaCl胁迫下，鱼腥藻PCC 7120胞外多糖中糖的组成比与普通培养条件下相比几乎没有变化。相比之下，发菜HK-01胞外多糖中糖的组成比在NaCl胁迫下发生了变化。这些结果表明，发菜HK-01胞外多糖对NaCl耐受性的影响来自于NaCl胁迫下荚膜多糖含量、糖组成的增加以及糖组成比例的变化。
The terrestrial cyanobacteriumNostocsp. HK-01 was more tolerant to NaCl stress than the aquatic cyanobacteriumAnabaenasp. PCC 7120 (also calledNostocsp. PCC 7120) which is similar toNostocsp. HK-01 in phylogeny. We determined the amount of extracellular polysaccharides (capsular and released polysaccharides) from the cells of both strains cultured with or without 200 mM NaCl. The amount of capsular polysaccharides fromNostocHK-01 reached approximately 65% of the dry weight whereas that fromAnabaenaPCC 7120 only occupied approximately 18% of the dry weight under NaCl stress.AnabaenaPCC 7120 grew well under NaCl stress when both polysaccharides fromNostocHK-01 were added to the culture. However,AnabaenaPCC 7120 barely grew under NaCl stress when both of its polysaccharides were added. Extracellular polysaccharides fromNostocHK-01 contained abundant fucose and glucuronic acid in comparison with those fromAnabaenaPCC 7120. Under NaCl stress, the composition ratios of sugars in the extracellular polysaccharides fromAnabaenaPCC 7120 hardly changed in comparison with those in ordinary culture conditions. By contrast, the composition ratios of sugars in the extracellular polysaccharides fromNostocHK-01 changed under NaCl stress. These results suggest that the effect of extracellular polysaccharides fromNostocHK-01 on NaCl tolerance comes from the increased amount of capsular polysaccharides, the sugar composition, and the change of the sugar composition ratio under NaCl stress.