(東北大學 材料與冶金學院，沈陽 110004)
摘 要: 通過研究含砷金精礦細菌氧化過程中各項工藝指標的變化，測定pH值、電壓、砷離子濃度、細菌數(shù)量和胞外聚合層中多糖含量及結構，探討胞外聚合層中多糖在細菌氧化含砷金精礦過程中的作用。結果表明：當電壓由500 mV升到650 mV、As(Ⅲ)快速轉(zhuǎn)化為As(Ⅴ)時，單個細菌可通過消耗胞外聚合層中的多糖來抵御砷離子的毒害；當電壓穩(wěn)定在650 mV、砷離子價態(tài)轉(zhuǎn)化減緩時，細菌胞外聚合層中的多糖參與礦物的氧化反應；在砷離子脅迫下，多糖含量降低幅度可超過20%，即細菌可通過改變單個菌體胞外聚合層中多糖的產(chǎn)量來防止細胞受到侵害。
關鍵字: 含砷金精礦；細菌冶金；胞外聚合層；多糖
gold concentrate biooxidation process
（School of Materials Science and Metallurgy, Northeastern University, Shenyang 110004, China）
Abstract:The change of the physicochemical indexes was researched to explore the role of the extracellular polymers in the biooxidation process of arsenic-bearing gold concentrate. The pH value, potential of hydrogen, arsenic ion concentration, bacterial count, polysaccharide content and chemical bond in the extra cellular polymers (EPS) were tested. The results show that the bacterium exhausts its polysaccharide to resist the toxicity of arsenic ion when the potential increases from 500 mV to 650 mV and As(Ⅲ) transfers to As(Ⅴ) rapidly, and the bacteria oxidizes the concentrate by its polysaccharide when the potential remains 650 mV and the conversion of the arsenic ion retards. Under the stress of arsenic ion, the polysaccharide content of extracellular polymers decreases by more than 20%, and the bacterium changes its polysaccharide content to prevent the toxic ions.
Key words: arsenic-bearing gold concentrate; bacteria metallurgy; extracellular polymers; polysaccharide
