(1. 上海應(yīng)用技術(shù)大學(xué) 材料科學(xué)與工程學(xué)院，上海 201418； 2. 東華大學(xué) 環(huán)境科學(xué)與工程學(xué)院，上海 201620)
摘 要: 銅萃取有機(jī)物對(duì)浸礦微生物的危害日益受關(guān)注，探討了Acidithiobacillus thiooxidans(At. thiooxidans)菌在被銅萃取有機(jī)物污染的低品位黃銅礦表面的吸附行為及其生物浸出特征。結(jié)果表明：由于萃取有機(jī)物的吸附增強(qiáng)了礦石表面疏水性與電負(fù)性，使At. thiooxidans細(xì)胞在受污染低品位黃銅礦表面的吸附率提高19%。然而，高細(xì)胞吸附率并不意味著高浸出率。在受污染低品位黃銅礦的生物浸出過(guò)程中，細(xì)胞生長(zhǎng)速度降低9%，銅浸出率降低29%。CLSM以及SEM觀察發(fā)現(xiàn)，在萃取有機(jī)物脅迫下，附著細(xì)胞的胞外多聚物(Extracellular polymeric substances, EPS)分泌受到抑制，勢(shì)必影響生物膜的構(gòu)建。在礦石被污染的情況下，有機(jī)膜覆蓋、細(xì)胞新陳代謝受抑制、EPS分泌減少，是導(dǎo)致浸出率降低的主要原因。
關(guān)鍵字: 嗜酸氧化硫硫桿菌；溶劑萃取；細(xì)胞吸附；胞外多聚物；黃銅礦
（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
