Departamento de Bioquímica, Facultad de Medicina, Universidad de Chile, Casilla 70086, Santiago, Chile.
Appl Environ Microbiol. 1994 Aug;60(8):2846-51. doi: 10.1128/aem.60.8.2846-2851.1994.
Conditions for the partial removal of lipopolysaccharide (LPS) from Thiobacillus ferrooxidans are described. Raising the pH of the solution containing the cells from pH 1.5 to pH 6.8 to 8.0 releases about 50% of the LPS without cell lysis. The release of LPS begins at pH 3.5, and it was not affected by EDTA concentration. Partial removal of LPS exposed higher amounts of a 40-kDa outer membrane protein in the bacteria, as detected by a dot immunoassay employing an antiserum against the T. ferrooxidans surface protein. This higher protein exposure and the reduced LPS content increased the hydrophobicity of the cell surface, as determined by an increased adhesion (50%) to hydrophobic sulfur prills and C-dodecanoic acid binding (2.5-fold) compared with control cells. In addition, adhesion of radioactively labeled microorganisms to a sulfide mineral was inhibited (40%) in the presence of previously added LPS. Our results suggest that not only LPS but also surface proteins probably play important roles in T. ferrooxidans adhesion to solid surfaces.
描述了从氧化亚铁硫杆菌中部分去除脂多糖（LPS）的条件。将含有细胞的溶液的 pH 值从 1.5 升高到 6.8 至 8.0，可在不使细胞裂解的情况下释放约 50%的 LPS。LPS 的释放始于 pH 值 3.5，且不受 EDTA 浓度的影响。通过斑点免疫测定法（采用针对 T. ferrooxidans 表面蛋白的抗血清）检测到，部分去除 LPS 后，细菌中暴露的 40kDa 外膜蛋白数量增加。这种更高的蛋白暴露和 LPS 含量的降低增加了细胞表面的疏水性，与对照细胞相比，疏水性硫磺颗粒的粘附（增加了 50%）和 C-十二烷酸结合（增加了 2.5 倍）。此外，在存在先前添加的 LPS 的情况下，放射性标记的微生物对硫化物矿物的粘附被抑制（40%）。我们的结果表明，不仅 LPS，而且表面蛋白可能在 T. ferrooxidans 对固体表面的粘附中起重要作用。
