论文部分内容阅读
比较研究生物浸出黄铜矿中pH值对嗜酸氧化亚铁硫杆菌分泌胞外蛋白和胞外多糖的影响。实验结果表明:当pH值为1.0、1.5、2.0和2.5时,在细菌生长的适应期、对数生长期和稳定期,矿物表面吸附菌分泌的胞外蛋白量比胞外多糖量多,相反,浸出溶液中的悬浮细菌分泌的胞外蛋白量比胞外多糖量少;悬浮细菌主要通过分泌胞外多糖而不是胞外蛋白来抵抗如高金属离子浓度和不适宜pH等不利生长溶液环境;吸附细菌分泌的胞外多糖和胞外蛋白量主要正相关于溶液酸度而不是可溶性金属离子总浓度。这表明细菌主要是通过分泌更多胞外多糖来对抗不利环境,而胞外蛋白可能在生物浸出系统的氧化-还原反应中起重要作用。
The effects of pH value in bioleaching chalcopyrite on the secretion of extracellular proteins and extracellular polysaccharides by Thiobacillus ferrooxidans were compared. The experimental results showed that when the pH was 1.0, 1.5, 2.0 and 2.5, the amount of extracellular protein secreted by mineral adsorbed bacteria was more than that of exopolysaccharide in the period of bacterial growth adaptation, logarithmic growth phase and stationary phase. On the contrary , The amount of extracellular protein secreted by the suspended bacteria in the leaching solution is less than that of the extracellular polysaccharide. The suspended bacteria mainly resist the unfavorable growth environment such as high metal ion concentration and unfavorable pH by exopolysaccharide instead of extracellular protein. The amount of extracellular polysaccharide and extracellular protein secreted by the adsorbing bacteria is mainly positively related to the solution acidity and not to the total soluble metal ion concentration. This suggests that the bacteria combat the adverse environment mainly through the secretion of more exopolysaccharides, and extracellular proteins may play an important role in the oxidation-reduction reaction of bioleaching systems.