中文摘要：

为考察浸矿细菌胞外多糖含量与砷离子的浓度和价态以及与浸矿细菌生长指标的关系,进而明确浸矿细菌抵御砷离子的生物对策,研究了不同浓度的As（Ⅲ）和As（Ⅴ）胁迫时,浸矿细菌胞外多糖的行为变化;通过测定菌液的pH、Eh、Fe^2＋浓度、菌数以及胞外多糖的含量,分析了各测定指标的相关性和线性关系。研究表明：As（Ⅲ）胁迫下,菌液的胞外多糖产量迅速增长,增幅超过34%,As（Ⅲ）的胁迫作用强于As（Ⅴ）;As（Ⅲ）胁迫使菌液胞外多糖含量的变异中有63.4%与Eh线性相关、有61.6%与Fe^2＋浓度线性相关、有71.4%与菌数线性相关;浸矿细菌通过代谢调控菌液的理化指标来调节胞外多糖的含量,进而抵抗砷离子的胁迫。

英文摘要：

The behavior changing of extracellular polysaccharide in leaching bacteria was studied under the different concentrations of As（Ⅲ）and As（Ⅴ）stress,in order to investigate the relationship between extracellular polysaccharide in leaching bacteria,concentration and valence of arsenic ion,and increase indexes of leaching bacteria,so as to find out biological strategies of leaching bacteria against arsenic ion.The pH,Eh,Fe^2＋concentration,the number of bacteria and the content of extracellular polysaccharide were measured to analysis the correlation and the linear relationship between them.The results show that under As（Ⅲ）stress,the production of extracellular polysaccharide in the bacterial liquid increases over 34%,As（Ⅲ）stress effect is stronger than As（Ⅴ）,and the extracellular polysaccharide content is linear correlation with Eh,Fe^2＋concentration and the number of bacteria at level of 63.4%,61.6% and 71.4% respectively.The results also indicate that leaching bacteria can regulate and control the growth indexes of the bacterial liquid to adjust the amount of extracellular polysaccharide,thus to resist arsenic ion stress.