邻苯二甲酸二甲酯污染对黑土微生物丰度和多样性的影响

摘要

邻苯二甲酸二甲酯（ DMP ）是一种在环境中广泛存在的有毒有机化合物，已被中国列为优先控制污染物之一。探讨了不同浓度DMP（0～40 mg·kg－1）污染对黑土微生物区系、功能菌群和多样性的影响。结果表明，DMP污染处理后，黑土中细菌和放线菌数量受到抑制，且抑制效应与DMP浓度呈正相关，黑土中真菌数量受到DMP污染的促进，且促进作用随着污染浓度的增加而增加；自生固氮菌、氨氧化细菌、亚硝酸氧化菌、有机磷细菌和无机磷细菌数量均受到DMP污染的抑制，铁细菌数量受到DMP污染的促进；黑土微生物丰富度和多样性受到DMP污染的抑制，且10、20和40 mg·kg－1污染浓度处理的抑制效应在25 d内并未消除。因此，在5～40 mg·kg－1 DMP污染条件下，黑土微生物区系结构和功能代谢菌群数量发生改变，微生物多样性降低，从而有可能使黑土的生态系统功能受到影响。%Dimethyl phthalate (DMP), a kind of toxic organic compound ubiquitous in the environment, has been listed as an environmental pollutant for priority control by the Ministry of Environmental Protection of China ( MEP ) . The purpose of this study is to explore impacts of DMP contamination ( 0-40 mg·kg-1 ) on microflora, functional groups and diversity of soil microbes in black soil. Results show that the populations of bacteria and actinomyces in the black soil were inhibited by DMP contamination and the impact was positively related to concentration of the pollutant. However, the a⁃mount of fungi in the soil was promoted and the effect increased with rising DMP concentration. Functional bacteria, like nitrogen fixing bacteria, ammonia oxidizing bacteria, nitrite⁃oxidizing bacteria, organic phosphorus⁃dissolving bacteria and inorganic phosphorus⁃dissolving bacteria, were all inhibited by DMP contamination, but iron bacteria were promoted by DMP contamination. DMP contamination decreased richness and Shannon⁃Wiener index of the soil microbes in the black soil and the negative impacts lasted for more than 25 d, in the treatments with concentration of the pollutant being 10, 20 and 40 mg·kg-1 . All the findings indicate that DMP in the range of 5-40 mg·kg-1 in concentration may affect structure of the soil microflora and populations of functional groups and biodiversity of the flora, and hence functions of the black soil ecosystem.