A defined medium to investigate sliding motility in a Bacillus subtilis flagella-less mutant.
A defined medium to investigate sliding motility in a Bacillus subtilis flagella-less mutant.
复制标题
一种定义的培养基，以研究枯草芽孢杆菌中无鞭毛突变体中的滑动运动。
DOI：
10.1186/1471-2180-6-31
复制
发表时间：
2006-03-17
期刊：
影响因子：
4.2
通讯作者：
Nguyen, Tam
中科院分区：
文献类型：
--
作者：
Fall, Ray;Kearns, Daniel B.;Nguyen, Tam
我们最近的研究表明，未经驯化的枯草芽孢杆菌菌株可以通过鞭毛独立的机制在丰富的半固体介质表面广泛定植，并表明滑动运动是表面迁移的原因。在这里，我们使用无鞭毛hag零突变体来检查和确认滑动运动性。使用确定的半固体培养基，我们确定枯草芽孢杆菌hag突变体分两个阶段在表面定植，首先是卷须状细胞簇，然后是大量的膜状膜。我们确定了卷须到薄膜过渡所需的宏观和微量营养素的水平。保证薄膜形成所需的大量营养物质（甘油、谷氨酸钠和磷酸钠）和无机营养物质（K+、Mg2+、Fe2+和Mn2+）的含量都足够。更详细地量化了K+需求，并确定了完全卷须覆盖（50 μM KCl）或薄膜覆盖（2-3 mM KCl）的阈值。此外，高亲和K+转运体（KtrAB）基因的破坏，而低亲和K+转运体（KtrCD）基因的破坏，强烈抑制卷须和薄膜的形成，并且可以通过高水平的KCl部分克服。用激光共聚焦扫描显微镜对hag卷须进行观察，发现其为多细胞结构，但细胞的组织性不像野生型枯草芽孢杆菌的细胞那样高。这些结果表明，枯草芽孢杆菌在各种常量或微量元素限制的情况下，可以利用滑动运动在表面定殖，以蔓状生长方式生长。如果营养平衡且充足，卷须之间的表面可以被坚固的表面膜定植。滑动运动可能代表了营养缺乏的细胞在自然环境中（如植物根）定植表面的一种策略，这里描述的培养基可能有助于研究这种生长表型。
We have recently shown that undomesticated strains of Bacillus subtilis can extensively colonize the surfaces of rich, semi-solid media, by a flagellum-independent mechanism and suggested that sliding motility is responsible for surface migration. Here we have used a flagella-less hag null mutant to examine and confirm sliding motility. Using a defined semi-solid medium we determined that a B. subtilis hag mutant colonized the surface in two stages, first as tendril-like clusters of cells followed by a profuse pellicle-like film. We determined the levels of macro- and micro-nutrients required for the tendril-to-film transition. Sufficient levels of each of the macronutrients, glycerol, Na-glutamate, and Na-phosphate, and inorganic nutrients, K+, Mg2+, Fe2+ and Mn2+, were required for robust film formation. The K+ requirement was quantified in more detail, and the thresholds for complete tendril coverage (50 μM KCl) or film coverage (2–3 mM KCl) were determined. In addition, disruption of the genes for the higher affinity K+ transporter (KtrAB), but not the lower affinity K+ transporter (KtrCD), strongly inhibited the formation of both tendrils and films, and could be partially overcome by high levels of KCl. Examination of hag tendrils by confocal scanning laser microscopy revealed that tendrils are multicellular structures, but that the cells are not as highly organized as cells in wild-type B. subtilis pellicles. These results suggest that B. subtilis can use sliding motility to colonize surfaces, using a tendril-like growth mode when various macronutrients or micronutrients are limiting. If nutrients are balanced and sufficient, the surfaces between tendrils can be colonized by robust surface films. Sliding motility may represent a strategy for nutrient-deprived cells to colonize surfaces in natural environments, such as plant roots, and the media described here may be useful in investigations of this growth phenotype.
登录
查看更多内容
影响因子：
3.2
作者：
Branda, SS;González-Pastor, JE;Kolter, R
通讯作者：
Kolter, R
影响因子：
3.2
作者：
Cosby, WM;Vollenbroich, D;Zuber, P
通讯作者：
Zuber, P
影响因子：
2.4
作者：
Lacasta, AM;Cantalapiedra, IR;Ramírez-Piscina, L
通讯作者：
Ramírez-Piscina, L
影响因子：
12.8
作者：
Lopez, C;Pons, MN;Morgenroth, E
通讯作者：
Morgenroth, E
影响因子：
3.2
作者：
MIREL, DB;CHAMBERLIN, MJ
通讯作者：
CHAMBERLIN, MJ