黑土微生物量和酶活性对邻苯二甲酸二丁酯污染的响应

摘要

Di-n-butyl phthalate (DBP), one of the phthalate esters, is ubiquitous environmental pollutant, and it is listed as an environmental priority pollutant by China State Environmental Protection Administration. The purpose of this study is to estimate the impact of DBP contamination on respiration, microbial biomass and enzyme activity in black soil. The results showed that the microbial respiratory rate and the content of the microbial biomass C in the black soil were promoted by the DBP contamination. The content of the microbial biomass N fluctuated greatly under the DBP contamination. The content of the microbial biomass P was correlated negatively with the DBP con-centration. Further, the activity of polyphenol oxidase was promoted after the inhibition occurred at the beginning. The activities of protease and invertase were promoted by the low DBP concentration, but inhibited by the high DBP concentration. The activity of urease was activated by DBP in the black soil. The activities of catalase and acid phosphatase was significantly inhibited by the DBP contamination in the black soil. The correlation analysis showed the correlation among the soil microbial biomass, the soil enzyme activity and the DBP concentration. Ac-cording to the results, DBP could be the key factor that alters the metabolism of the microorganisms in the black soil, and impacts the ecosystem functions in the black soil.%邻苯二甲酸二丁酯(di-n-butyl phthalate, DBP)是一种在环境中广泛存在的有毒有机化合物,已被我国列为优先控制污染物之一。本研究探讨了不同浓度的DBP污染对黑土呼吸、微生物量以及黑土酶活性的影响。结果表明, DBP污染处理的黑土呼吸速率和微生物量碳较对照均显著增加；微生物氮在DBP污染过程中呈“降低-升高-降低”波动性变化；微生物磷与DBP污染浓度呈显著负相关；DBP对黑土多酚氧化酶表现为先促进后抑制,对转化酶和蛋白酶活性表现为低浓度促进而高浓度抑制；在DBP污染过程中脲酶呈现被激活状态；黑土过氧化氢酶和酸性磷酸酶均受到DBP污染的显著抑制。通过相关性分析发现,土壤微生物量、土壤酶活性与DBP污染浓度之间存在着高度的相关性。由此可推断, DBP污染改变了黑土呼吸、微生物量和酶学活性的代谢特征,进而有可能影响了黑土的生态系统功能,威胁到黑土的可持续利用。