Effects of Exopolysaccharide Production on Liquid Vegetative Growth, Stress Survival, and Stationary Phase Recovery in Myxococcus xanthus
Effects of Exopolysaccharide Production on Liquid Vegetative Growth, Stress Survival, and Stationary Phase Recovery in Myxococcus xanthus
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DOI：
10.1007/s12275-012-1349-5
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发表时间：
2012-04-01
影响因子：
3
通讯作者：
Shi, Wenyuan
中科院分区：
文献类型：
--
作者：
Hu, Wei;Wang, Jing;Shi, Wenyuan
黄色粘球菌胞外多糖(EPS)是一种调控良好的细胞表面成分。除了已知的在固体表面上的社会运动和子实体形成的功能外，EPS还被认为在液体介质中的多细胞聚集中发挥作用，尽管这种现象还没有得到很好的研究。在这份报告中，我们证实了在液体中形成的黄花草菌团与EPS水平相关，并证明了EPS包裹的细胞团具有类似生物膜的结构。在生理上相关的EPS浓度下，块状细胞保护细胞，而缺乏EPS的细胞显示出长期存活率和对应激条件的抵抗力显著降低。然而，过多的EPS产量对营养生长是不利的，在延长的稳定期，由于细胞被困在块状基质中，活细胞回收率下降。因此，黄曲霉产EPS的最适条件对其在液体中的正常生理功能具有重要意义。
Exopolysaccharide (EPS) of Myxococcus xanthus is a well-regulated cell surface component. In addition to its known functions for social motility and fruiting body formation on solid surfaces, EPS has also been proposed to play a role in multi-cellular clumping in liquid medium, though this phenomenon has not been well studied. In this report, we confirmed that M. xanthus clumps formed in liquid were correlated with EPS levels and demonstrated that the EPS encased cell clumps exhibited biofilm-like structures. The clumps protected the cells at physiologically relevant EPS concentrations, while cells lacking EPS exhibited significant reduction in long-term viability and resistance to stressful conditions. However, excess EPS production was counterproductive to vegetative growth and viable cell recovery declined in extended late stationary phase as cells became trapped in the matrix of clumps. Therefore, optimal EPS production by M. xanthus is important for normal physiological functions in liquid.