摘要
为探究红霉素在水环境的生物归趋,本试验采用^(14)C示踪法,建立蝌蚪-浮萍模拟水生生态系统和人工蔬菜水培系统,研究红霉素在蝌蚪、浮萍和食用蔬菜体内的吸收转运特征,并探讨2种不同来源[帕霍基腐殖土(PP)和萨旺泥河(SR)]的水体溶解性有机质(DOM)对其生物可利用度的影响。结果表明,20μg·L^(-1)污染水平下,水体中红霉素能够通过表皮吸收进入水生生物,且其在不同生物中的吸收富集特征存在差异。模拟水生生态系统试验表明,纯水中红霉素能够快速为浮萍吸收富集,并于72 h内达到平衡浓度1.35±0.11 nmol·g^(-1)(干重),当水体中有DOM存在时,红霉素在浮萍体内的吸收富集受到显著抑制(P<0.05),且SR较PP抑制作用更强;红霉素在蝌蚪体内随着时间推移不断富集,360 h时浓度达到峰值1.20±0.05 nmol·g^(-1),SR能够显著抑制蝌蚪对红霉素的吸收;SR对红霉素在浮萍和蝌蚪体内吸收的抑制作用更强,这可能与SR较PP更易与红霉素结合有关。水培蔬菜试验结果表明,水体中红霉素在油菜和生菜体内的富集系数分别为1.65±0.18(地上部)和1.36±0.23 L·kg^(-1)(地上部),显著低于蝌蚪和浮萍(58.77±0.63和49.58±4.03 L·kg^(-1)),且可以通过根部吸收运转至水培蔬菜茎叶,但其转运系数均小于1,表明红霉素不易在试验蔬菜体内向上转运;DOM对红霉素在油菜和生菜中的吸收富集无显著影响。本研究为科学评价红霉素的生态安全性提供了理论依据。
As one of the most frequently used antibiotic drugs, erythromycin(ERY) pollution is ubiquitous in aquatic environment. However, the fate of ERY in aquatic environment has not been fully understood. In this study, the uptake and transportation of 14C-ERY in aquatic plants and animals were studied by14C tracing basing on a simulated duckweed-tadpole aquatic ecosystem and an artificial vegetable hydroponics system. The effects of two(SR and PP) dissolved organic matters(DOM) on the bioaccessibility of ERY to duckweed, tadpole and edible vegetables were also elucidated. The results showed that the waterborne ERY at a concentration of 20 μg L^-1 was accessible to both the water plants and animals, and different uptake and accumulation patterns were observed between the different biotas. Results from the aquatic ecosystem experiment demonstrated that ERY could be absorbed by duckweed quickly and an apparent equilibrium concentration of 1.35±0.11 nmol·g^-1 was reached within 72 h. The absorption of ERY in duckweed in treatments with DOM were significantly inhibited compared to the control treatment without DOM, and the inhibition influence is generally greater for treatment with DOM from SR than PP. ERY was continuously accumulated with time in the bodies of tadpole and reached to its maximum concentration(1.20±0.05 nmol·g^-1) at the end of 360 h exposure. The accumulation of ERY in tadpole was inhibited when the SR was present in water. The greater inhibition of ERY absorption by SR than PP could be attributed to the higher bonding rate between SR and ERY. The bioaccumulation coefficients of ERY in duckweed, tadpole, rape and lettuce were 58.77±0.63 and 49.58±4.03, 1.65±0.18(shoot) and 1.36±0.23(shoot) L·kg^-1, respectively. The translocation factors of ERY in both the lettuce and pakchoi were < 1, which potentially suggesting that ERY may not be tending to be transported upward. The presence of DOM had no significant influence on the accumulation of ERY in lettuce or pakchoi. This study reported the effect of DOM on the uptake and accumulation of ERY in aquatic organisms for the first time, and the absorption and accumulation characteristics of ERY in edible vegetables were firstly studied. It is of great significance for evaluating the ecological safety of ERY more precisely.
作者
刘志平
顾鑫
余凯翔
张素芬
叶庆富
王伟
LIU Zhiping;GU Xin;YU Kaixiang;ZHANG Sufen;YE Qingfu;WANG Wei(Key Laboratory of Nuclear-Agricultural Science, Ministry of Agriculture/Institute of Nuclear-Agricultural Science, Zhejiang University, Hangzhou, Zhejiang 310029)
出处
《核农学报》
CAS
CSCD
北大核心
2019年第2期337-345,共9页
Journal of Nuclear Agricultural Sciences
基金
国家自然科学基金(21577120)
国家重点研发计划重点专项(2016YFD0800207)
