Bomchil Natalia, Watnick Paula, Kolter Roberto
Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA.
J Bacteriol. 2003 Feb;185(4):1384-90. doi: 10.1128/JB.185.4.1384-1390.2003.
The formation of biofilms is thought to play a key role in the environmental survival of the marine bacterium Vibrio cholerae. Although the factors involved in V. cholerae attachment to abiotic surfaces have been extensively studied, relatively little is known about the mechanisms involved in the subsequent maturation of the biofilms. Here we report the identification of a novel gene, which we have named mbaA (for maintenance of biofilm architecture), that plays a role in the formation and maintenance of the highly organized three-dimensional architecture of V. cholerae El Tor biofilms. We demonstrate that although the absence of mbaA does not significantly affect the initial attachment of cells onto the surface, it leads to the formation of biofilms that lack the typical structure, including the pillars of cells separated by fluid-filled channels that are evident in mature wild-type biofilms. Microscopic analysis indicates that the absence of mbaA leads to an increase in the amount of extracellular matrix material in the biofilms. The predicted mbaA product is a member of a family of regulatory proteins, containing GGDEF and EAL domains, suggesting that MbaA regulates the synthesis of some component of the biofilm matrix.
生物膜的形成被认为在海洋细菌霍乱弧菌的环境生存中起着关键作用。尽管已经对霍乱弧菌附着于非生物表面所涉及的因素进行了广泛研究，但对于生物膜随后成熟过程中所涉及的机制却知之甚少。在此，我们报告鉴定出一个新基因，我们将其命名为mbaA（用于维持生物膜结构），该基因在霍乱弧菌El Tor生物膜高度有序的三维结构的形成和维持中发挥作用。我们证明，虽然缺失mbaA不会显著影响细胞在表面的初始附着，但会导致形成缺乏典型结构的生物膜，包括在成熟野生型生物膜中明显可见的由充满液体的通道分隔的细胞柱。显微镜分析表明，缺失mbaA会导致生物膜中细胞外基质物质的量增加。预测的mbaA产物是一个含有GGDEF和EAL结构域的调节蛋白家族的成员，这表明MbaA调节生物膜基质某些成分的合成。
