School of Chemical Engineering The University of Queensland, Brisbane QLD 4072, Australia.
Australian Institute for Bioengineering and Nanotechnology, ANFF-Q The University of Queensland, Brisbane QLD 4072, Australia.
Colloids Surf B Biointerfaces. 2014 Mar 1;115:229-36. doi: 10.1016/j.colsurfb.2013.11.047. Epub 2013 Dec 1.
The adhesion of acidophilic bacteria to mineral surfaces is an important phenomenon in bioleaching processes. In this study, functionalized colloidal probes covered by bioleaching bacterial cells (Acidithiobacillus thiooxidans and Leptospirillum ferrooxidans) were developed and used to sense specific adhesion forces to a silica surface and a pyrite surface in various solutions. Experimentally, recorded retraction curves of A. thiooxidans revealed sawtooth features that were in good agreement with the wormlike chain model, while that of L. ferrooxidans exhibited stair-step separation. The magnitudes of adhesion forces and snap-off distances were strongly influenced by the ionic strength and pH. Macroscopic surface properties including hydrophobicity and surface potential for bacterial cells and substrata were measured by a sessile drop method and microelectrophoresis. The ATR-FTIR spectra indicated the presence of different types of biopolymers on two strains of bacteria.
嗜酸细菌在矿物表面的附着是生物浸出过程中的一个重要现象。在这项研究中，开发了功能化胶体探针，其表面覆盖有生物浸出细菌细胞（氧化硫硫杆菌和氧化亚铁硫杆菌），并用于在各种溶液中感测特定的硅石表面和黄铁矿表面的粘附力。在实验中，记录的 A. thiooxidans 的回缩曲线显示出锯齿状特征，与蠕虫链模型吻合良好，而 L. ferrooxidans 的则表现出阶跃分离。粘附力和断开距离的大小强烈受离子强度和 pH 值的影响。细菌细胞和基质的宏观表面性质（疏水性和表面电势）通过静滴法和微电泳进行测量。ATR-FTIR 谱表明两种细菌表面存在不同类型的生物聚合物。
