Exopolysaccharide microchannels direct bacterial motility and organize multicellular behavior
Exopolysaccharide microchannels direct bacterial motility and organize multicellular behavior
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DOI：
10.1038/ismej.2016.60
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发表时间：
2016-11-01
期刊：
影响因子：
11
通讯作者：
Auer, Manfred
中科院分区：
文献类型：
--
作者：
Berleman, James E.;Zemla, Marcin;Auer, Manfred
粘细菌是一类土壤细菌，它们形成的生物膜具有复杂的结构、排列整齐的多层群或子实体结构，这些结构是含有粘孢子的简单或分枝聚集体。在这里，我们研究了基质胞外多糖(EPS)在这些表面栖息的细菌细胞组织中的结构作用。利用延时光学显微镜和荧光显微镜，以及透射电子显微镜和聚焦离子束/扫描电子显微镜(FIB/SEM)电子显微镜，我们发现黄色粘球菌在生物膜中的细胞组织依赖于EPS微通道的形成。细胞在EPS微通道的三维结构中高度组织，这是细胞在表面上对准和推进所必需的。缺乏EPS的突变体缺乏细胞定向，菌落迁移能力差。纯化的、无细胞的EPS保留了通道样结构，可以弥补EPS突变的运动性缺陷。此外，EPS为黄曲霉的简单土丘和鳄鱼软骨霉复杂的树状结构中的子实体形成提供了合作结构。我们进一步研究了EPS影响群落结构的可能性，作为一种共享资源，促进了密切相关的黄曲霉分离物之间的合作迁移。
The myxobacteria are a family of soil bacteria that form biofilms of complex architecture, aligned multilayered swarms or fruiting body structures that are simple or branched aggregates containing myxospores. Here, we examined the structural role of matrix exopolysaccharide (EPS) in the organization of these surface-dwelling bacterial cells. Using time-lapse light and fluorescence microscopy, as well as transmission electron microscopy and focused ion beam/scanning electron microscopy (FIB/SEM) electron microscopy, we found that Myxococcus xanthus cell organization in biofilms is dependent on the formation of EPS microchannels. Cells are highly organized within the three-dimensional structure of EPS microchannels that are required for cell alignment and advancement on surfaces. Mutants lacking EPS showed a lack of cell orientation and poor colony migration. Purified, cell-free EPS retains a channel-like structure, and can complement EPS-mutant motility defects. In addition, EPS provides the cooperative structure for fruiting body formation in both the simple mounds of M. xanthus and the complex, tree-like structures of Chondromyces crocatus. We furthermore investigated the possibility that EPS impacts community structure as a shared resource facilitating cooperative migration among closely related isolates of M. xanthus.