Key Laboratory of Agricultural Environment in Universities of Shandong, College of Resources and Environment, Shandong Agricultural University, 61 Daizong Road, Taian, 271018, People's Republic of China.
State Key Laboratory of Water Resources and Water Hydropower Engineering Science, Wuhan University, Hubei, 430072, People's Republic of China.
Environ Geochem Health. 2019 Dec;41(6):2593-2606. doi: 10.1007/s10653-019-00307-5. Epub 2019 May 9.
Antibiotics and heavy metals have long-term potential toxicity to the environment, and their residuals in agricultural soils are receiving more and more attention. To evaluate the ecotoxicological effects of enrofloxacin and cadmium on soil enzymatic activities and microbial community structure, soil samples were exposed to individual and combined contaminants over 28 days. The results indicated that the toxic effects of enrofloxacin alone on soil enzymatic activities were relatively small and showed no concentration dependence. In contrast, significant inhibition of soil enzymatic activities was observed upon cadmium contamination by itself. Overall, the combination of two contaminants also has toxic effect on enzymatic activities; an antagonism between enrofloxacin and cadmium was observed. On 14 and 21 days, individual enrofloxacin and cadmium reduced average well color development (AWCD), Shannon, McIntosh, Simpson indices, and substrate utilization, except for Shannon, McIntosh, Simpson indices of the cadmium 0.4 mmol/kg treatment were higher than the control on 21 days. In general, combined treatments led to higher value of these microbial diversity indicators than those found under separate contamination, although there were some exceptions. With the increase in enrofloxacin concentration, the utilization of any carbon source by the microorganisms gradually decreased. In addition, the AWCD value and substrate utilization decreased as time increased. In the separate and combined contaminant treatments, the order of substrate utilization by soil microorganisms was aliphatics > amino acids > saccharides > metabolites. Thus, enrofloxacin and cadmium had a variable but generally negative influence on soil enzymatic activities and microbial community structure.
抗生素和重金属对环境具有长期潜在毒性，它们在农业土壤中的残留越来越受到关注。为了评估恩诺沙星和镉单独及联合暴露对土壤酶活性和微生物群落结构的生态毒性效应，将土壤样品分别暴露于单一和混合污染物中 28 天。结果表明，恩诺沙星单独作用对土壤酶活性的毒性效应相对较小，且无浓度依赖性。相反，镉单独污染显著抑制土壤酶活性。总体而言，两种污染物的联合作用也对酶活性具有毒性效应；恩诺沙星和镉之间存在拮抗作用。在第 14 天和第 21 天，单一的恩诺沙星和镉降低了平均好氧颜色发展（AWCD）、香农、麦克因托什、辛普森指数和底物利用率，除了第 21 天镉 0.4mmol/kg 处理的香农、麦克因托什、辛普森指数高于对照。一般来说，与单一污染相比，联合处理导致这些微生物多样性指标的值更高，但也存在一些例外。随着恩诺沙星浓度的增加，微生物对任何碳源的利用逐渐减少。此外，AWCD 值和底物利用率随着时间的增加而降低。在单独和联合污染物处理中，土壤微生物利用底物的顺序为脂肪族 > 氨基酸 > 糖类 > 代谢物。因此，恩诺沙星和镉对土壤酶活性和微生物群落结构的影响存在差异，但总体上呈负向。
