中文摘要：

考察了序批式好氧生物反应器（SBR）中，重金属铬离子对溶解性微生物产物（SMP）总量、分子量分布及其组成中多聚糖、蛋白质和DNA含量的影响．铬离子的生物容许浓度在2mg·l^-1之下，SMP总量与铬离子浓度存在指数关系：SMP=24．94e^0.593C．SMP的分子量呈双峰分布，且分子量小于1kDa的部分基本上占50％以上．SMP中的DNA含量随铬离子浓度的增加而降低，在显著水平n=0．05时，DNA含量与铬离子浓度呈线性相关．

英文摘要：

The effects of Cr^6＋ on amount, molecule weight （MW） distribution, and content of polysaccharide, protein, DNA in soluble microbial products （SMP）were investigated in aerobic sequencing batch reactors. The microbial permissible concentration of Cr^6＋ was 2 mg·l^-1 under this experimental condition. Below the microbial permissible concentration of Cr^6＋ , the amount of SMP was an exponential function of concentration of Cr^6＋ , in which SMP = 24.94e^0.593C The MW distribution of SMP manifested a bimodal pattern with more than 50% of SMP having a MW less than 1 kDA. The content of DNA in SMP reduced with the increase of concentration of Cr^6＋. By the test of significance, it was found that the content of DNA was in linear relation with concentration of Cr^6＋ at the 5 % significant level.