(1. 上海应用技术大学 材料科学与工程学院，上海 201418； 2. 东华大学 环境科学与工程学院，上海 201620)
摘 要: 铜萃取有机物对浸矿微生物的危害日益受关注，探讨了Acidithiobacillus thiooxidans(At. thiooxidans)菌在被铜萃取有机物污染的低品位黄铜矿表面的吸附行为及其生物浸出特征。结果表明：由于萃取有机物的吸附增强了矿石表面疏水性与电负性，使At. thiooxidans细胞在受污染低品位黄铜矿表面的吸附率提高19%。然而，高细胞吸附率并不意味着高浸出率。在受污染低品位黄铜矿的生物浸出过程中，细胞生长速度降低9%，铜浸出率降低29%。CLSM以及SEM观察发现，在萃取有机物胁迫下，附着细胞的胞外多聚物(Extracellular polymeric substances, EPS)分泌受到抑制，势必影响生物膜的构建。在矿石被污染的情况下，有机膜覆盖、细胞新陈代谢受抑制、EPS分泌减少，是导致浸出率降低的主要原因。
关键字: 嗜酸氧化硫硫杆菌；溶剂萃取；细胞吸附；胞外多聚物；黄铜矿
（1. School of Materials Science and Engineering, Shanghai Institute of Technology, Shanghai 201418, China; 2. School of Environmental Science and Engineering, Donghua University, Shanghai 201620, China）
Abstract:The impacts of copper solvent extraction (SX) organics on bioleaching microorganism are attracting more and more attentions. The attachment of the cells of Acidithiobacillus thiooxidans (At.thiooxidans) on the low grade chalcopyrite ore, contaminated by SX organics, and the subsequent bioleaching process were investigated. The results show that the attachment of the cells to the SX organics contaminated-ores increases by 19% since the surface hydrophobicity and electronegativity of the ores are enhanced by SX organics. However, a higher level of attachment of the cells does not mean the better bioleaching efficiency indeed. For bioleaching of the contaminated low-grade chalcopyrite ores, the metabolic rate of At.thiooxidans and the copper extraction efficiency decreases by 9% and 29%, respectively. Impacted by SX organics, the EPS secretion of At.thiooxidans seems to be inhibited, which retards the construction of the biofilm. Conclusively, being covered surface of the ores, inhibited metabolism and EPS secretion for the cells might be the primary reasons for the low bioleaching efficiency of the SX organics contaminated-ores.
Key words: Acidithiobacillus thiooxidans; copper solvent extraction; bacterial adsorption; extracellular polymeric substances; chalcopyrite
