Department of Civil and Environmental Engineering, Stanford University, Stanford, CA, USA.
FEMS Microbiol Lett. 2010 Jul 1;308(1):76-83. doi: 10.1111/j.1574-6968.2010.01995.x. Epub 2010 Apr 21.
Type IV pili and a putative EPS biosynthetic gene cluster (mxdABCD) have been implicated previously in biofilm formation in Shewanella oneidensis MR-1. Here, we report that the mannose-sensitive hemagglutinin (MSHA) pilus mediates a reversible, d-mannose-sensitive association of cells to the substratum surface or to other cells that is critical within the first 5 microm of the biofilm from the substratum. The presence of the MSHA pilus alone is insufficient to confer biofilm-forming capacity; its activity, as mediated by the putative pilus retraction motor protein, PilT, is also required. Deletion of pilD, encoding the type IV pili prepilin peptidase, revealed that additional PilD substrate(s) may be involved in biofilm formation beyond the major structural pilin of the MSHA pilus. We also present data showing that the MSHA pilus and mxd genes encode for a complementary set of molecular machineries that constitute the dominant mechanisms enabling biofilm formation in this microorganism under hydrodynamic conditions.
先前已经有研究表明，在希瓦氏菌属 MR-1 中，IV 型菌毛和一个假定的 EPS 生物合成基因簇（mxdABCD）与生物膜形成有关。在这里，我们报告称，甘露糖敏感血凝素（MSHA）菌毛介导了细胞与基质表面或其他细胞之间可逆的、D-甘露糖敏感的关联，这在生物膜从基质开始的最初 5 微米内是至关重要的。单独存在 MSHA 菌毛不足以赋予生物膜形成能力；还需要其活性，由假定的菌毛回缩运动蛋白 PilT 介导。缺失编码 IV 型菌毛前导肽酶的 pilD 基因表明，除了 MSHA 菌毛的主要结构菌毛之外，可能还存在其他 PilD 底物参与生物膜形成。我们还提供了数据，表明 MSHA 菌毛和 mxd 基因编码了一套互补的分子机械，这些机械构成了该微生物在水动力条件下形成生物膜的主要机制。
