Eboigbodin Kevin E, Ojeda Jesus J, Biggs Catherine A
Department of Chemical and Process Engineering and Department of Civil and Structural Engineering, The University of Sheffield, Sheffield S1 3JD, U.K.
Langmuir. 2007 Jun 5;23(12):6691-7. doi: 10.1021/la063404z. Epub 2007 May 12.
Bacteria exist as aggregates or in biofilms to help with adaptation and protection from environmental stresses. The hypothesis that is tested in this paper is that the relative presence of glucose in the media, at the beginning of the growth phase, influences the surface chemistry of the cell, which as a consequence reduces the tendency for the cells to interact and form aggregates. In this study, we used Escherichia coli (E. coli) MG1655 as a model organism and measured the change in the surface chemistry of cells harvested at different growth phases, which had been cultured in Luria-Bertani media with and without the addition of glucose, using potentiometric titration and infrared spectroscopy. Cells, cultivated with the additional supplement of glucose at the beginning of the growth phase, displayed a higher concentration of bacterial surface functional groups and a variation in outer membrane proteins. As a consequence, the tendency for cell-to-cell attachment was significantly reduced. Our findings therefore revealed that glucose limits aggregation in E. coli MG1655 by altering the concentration of functional groups from macromolecules present on the bacterial surface.
细菌以聚集体或生物膜的形式存在，以帮助适应环境压力并免受其影响。本文所检验的假设是，在生长阶段开始时培养基中葡萄糖的相对含量会影响细胞的表面化学性质，从而降低细胞相互作用并形成聚集体的倾向。在本研究中，我们使用大肠杆菌MG1655作为模式生物，通过电位滴定法和红外光谱法测量了在添加和不添加葡萄糖的Luria-Bertani培养基中培养的、处于不同生长阶段收获的细胞的表面化学性质变化。在生长阶段开始时添加葡萄糖培养的细胞，其细菌表面官能团浓度较高，外膜蛋白也有变化。因此，细胞间附着的倾向显著降低。我们的研究结果表明，葡萄糖通过改变细菌表面大分子官能团的浓度来限制大肠杆菌MG1655中的聚集。
