School of Minerals processing and Bioengineering, Central south University, Changsha, PR China.
BMC Microbiol. 2010 Nov 16;10:291. doi: 10.1186/1471-2180-10-291.
Although solid surface-associated biofilm development of S. oneidensis has been extensively studied in recent years, pellicles formed at the air-liquid interface are largely overlooked. The goal of this work was to understand basic requirements and mechanism of pellicle formation in S. oneidensis.
We demonstrated that pellicle formation can be completed when oxygen and certain cations were present. Ca(II), Mn(II), Cu(II), and Zn(II) were essential for the process evidenced by fully rescuing pellicle formation of S. oneidensis from the EDTA treatment while Mg (II), Fe(II), and Fe(III) were much less effective. Proteins rather than DNA were crucial in pellicle formation and the major exopolysaccharides may be rich in mannose. Mutational analysis revealed that flagella were not required for pellicle formation but flagellum-less mutants delayed pellicle development substantially, likely due to reduced growth in static media. The analysis also demonstrated that AggA type I secretion system was essential in formation of pellicles but not of solid surface-associated biofilms in S. oneidensis.
This systematic characterization of pellicle formation shed lights on our understanding of biofilm formation in S. oneidensis and indicated that the pellicle may serve as a good research model for studying bacterial communities.
尽管近年来人们广泛研究了 S. oneidensis 固着表面相关生物膜的发展情况，但在气液界面形成的菌膜却在很大程度上被忽视了。本研究的目的是了解 S. oneidensis 菌膜形成的基本要求和机制。
我们证明，当存在氧气和某些阳离子时，菌膜可以完全形成。Ca(II)、Mn(II)、Cu(II)和 Zn(II)是该过程所必需的，这可以通过 EDTA 处理对 S. oneidensis 进行完全挽救来证明，而 Mg(II)、Fe(II)和 Fe(III)的效果则差得多。蛋白质而不是 DNA 对菌膜形成至关重要，且主要的胞外多糖可能富含甘露糖。突变分析表明，鞭毛不是菌膜形成所必需的，但鞭毛缺失突变体大大延迟了菌膜的形成，这可能是由于在静态培养基中生长减少所致。该分析还表明，在 S. oneidensis 中 AggA 型 I 型分泌系统是菌膜形成所必需的，但不是固着表面相关生物膜形成所必需的。
本研究对菌膜形成进行了系统的表征，加深了我们对 S. oneidensis 生物膜形成的理解，并表明菌膜可能是研究细菌群落的良好研究模型。
