中文摘要：

细菌的附件上的细胞外的 DNA (eDNA ) 的效果用 Escherichia coli 被描绘， DNase 我，和 DNA 的几种不同类型。这里，我们证明 eDNA 以一个集中依赖者方法提高了细菌的附件到稳固的表面。plasmid DNA 或染色体 DNA，平或真核细胞的 DNA 碎片显示出提升效果，建议细菌的附件上的 DNA 的效果是 nonspecific。eDNA 的这提升效果从连接词 pili 的是可分离的。在一个静态的文化系统， biofilm 能甚至与活跃 DNase 的存在形成我。DNase 我高效地损害了 bacterium-to-bacterium 粘附和 microcolony 形成，但是在细菌的附件上有小效果到稳固的表面和成熟 biofilm。因而，这研究在自然环境在细菌的 biofilm 形成为 DNA 的角色提供合理描述。

英文摘要：

The effect of extracellular DNA（eDNA） on bacterial attachment was characterized using Escherichia coli,DNase I,and several different kinds of DNA.Here,we showed that eDNA en-hanced bacterial attachment to solid surface in a concentra-tion-dependent way.Either plasmid DNA or chromosome DNA,even or eukaryotic DNA fragments showed the promotion effect,suggesting that the effect of DNA on bacterial attachment is non-specific.This promotion effect of eDNA is separable from that of conjunctive pili.In a static culture system,biofilm can form even with the presence of active DNase I.DNase I impaired bacte-rium-to-bacterium adhesion and microcolony formation efficiently but had little effect on bacterial attachment to a solid surface and mature biofilm.Consequently,this study provides a rational de-scription for the role of DNA in bacterial biofilm formation in natural environments.