Chen Gang, Zhu Honglong
Civil and Environmental Engineering, FAMU-FSU College of Engineering, Tallahassee, FL 32310, USA.
Colloids Surf B Biointerfaces. 2005 Jul 25;44(1):41-8. doi: 10.1016/j.colsurfb.2005.05.012.
Bacterial adhesion to silica sand was related to variations in system Gibbs energy DeltaG(adh). Two typical Gram-positive bacterial strains of Streptococcus mitis and Lactobacillus casei were used as the model bacteria in this research. Impacts of solution chemistry and goethite coating of silica sand on bacterial adhesion were also explored. S. mitis and L. casei had negative DeltaG(adh) with both uncoated and goethite-coated silica sand, demonstrating their adhesion potentials to these substrate. After goethite coating, DeltaG(adh) decreased (negatively increased) for both S. mitis and L. casei. In the presence of rhamnolipid biosurfactant, DeltaG(adh) increased (negatively decreased) in answer to the increase of the rhamnolipid biosurfactant concentration. Bacterial percentage adhesion to silica sand corresponded to DeltaG(adh). This study demonstrated that bacterial adhesion to substrate could be explained in terms of bacterial, substratum and intervening medium physicochemical surface properties, which can be independently determined based on contact angle measurements.
细菌对硅砂的粘附与体系吉布斯自由能ΔG(adh)的变化有关。本研究选用两种典型的革兰氏阳性细菌——缓症链球菌和干酪乳杆菌作为模式细菌。还探讨了溶液化学性质和硅砂的针铁矿涂层对细菌粘附的影响。缓症链球菌和干酪乳杆菌对未涂层和针铁矿涂层的硅砂均具有负的ΔG(adh)，表明它们对这些底物具有粘附潜力。针铁矿涂层后，缓症链球菌和干酪乳杆菌的ΔG(adh)均降低（负向增加）。在鼠李糖脂生物表面活性剂存在的情况下，随着鼠李糖脂生物表面活性剂浓度的增加，ΔG(adh)增加（负向降低）。细菌对硅砂的粘附百分比与ΔG(adh)相对应。本研究表明，细菌对底物的粘附可以根据细菌、底物和中间介质的物理化学表面性质来解释，这些性质可以通过接触角测量独立确定。
