School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China.
School of Life Sciences, Central South University, Changsha, 410083, China.
Chemosphere. 2021 Aug;276:130208. doi: 10.1016/j.chemosphere.2021.130208. Epub 2021 Mar 9.
Silver ion (Ag) is an important catalyst to improve chalcopyrite bio-dissolution, but its effects on initial adhesion behaviors and biofilm formation of acidophiles onto metal sulfide were still unknown. In this study, initial attachment behavior and adhesion force in the presence of Ag (0, 1, 2, 5, 10 and 20 mg/L) were comparatively analyzed for Acidianus manzaensis YN-25. Biofilm was observed by fluorescent images in the presence of 0, 1 and 2 mg/L Ag. X-ray photoelectron spectroscopy (XPS) corroborated the catalytic mechanisms of Ag to biofilm formation. Results showed that Ag could significantly promote the attachment of cells on chalcopyrite, and the optimum concentration of Ag was 2 mg/L with the biggest percentage of attached cells (74%), followed by 5 mg/L (71%), whereas that for the control (0 mg/L) was only 61%. Ag significantly increased the interaction force between A. manzaensis YN-25 and chalcopyrite. Compared with the control, larger coverage of biofilm (up to 40% versus 32%) and more corrosion pits were observed on chalcopyrite in the presence of 2 mg/L Ag. Moreover, Ag catalyzed chalcopyrite corrosion and accelerated biofilm formation by producing a loose porous AgS layer and Ag to decrease the resistivity. The live/dead ratio was small with a range of 0.31-1.38, suggesting that dead cells were a great slice during the whole life-cycle of biofilm on chalcopyrite. This report offers a profound insight into the promotion mechanism of Ag on adhesion behaviors and biofilm formation by thermoacidophilic archaeon under extremely acidic conditions.
银离子（Ag）是提高黄铜矿生物溶解的重要催化剂，但它对嗜酸微生物初始附着行为和生物膜形成在金属硫化物上的影响尚不清楚。在这项研究中，比较分析了嗜酸菌 Acidianus manzaensis YN-25 在存在 Ag（0、1、2、5、10 和 20 mg/L）时的初始附着行为和附着力。在 0、1 和 2 mg/L Ag 存在的情况下，通过荧光图像观察生物膜。X 射线光电子能谱（XPS）证实了 Ag 对生物膜形成的催化机制。结果表明，Ag 能显著促进细胞在黄铜矿上的附着，Ag 的最佳浓度为 2 mg/L，附着细胞的比例最大（74%），其次为 5 mg/L（71%），而对照（0 mg/L）仅为 61%。Ag 显著增加了 A. manzaensis YN-25 和黄铜矿之间的相互作用力。与对照相比，在存在 2 mg/L Ag 时，黄铜矿上生物膜的覆盖率（高达 40%对 32%）和更多的腐蚀坑更大。此外，Ag 通过产生疏松多孔的 AgS 层和降低电阻率来催化黄铜矿腐蚀和加速生物膜形成。活/死比小，范围为 0.31-1.38，表明在生物膜在黄铜矿上的整个生命周期中，死细胞是一个很大的片段。本报告深入了解了在极端酸性条件下嗜热嗜酸古菌对 Ag 促进附着行为和生物膜形成的促进机制。
