Wang Wei-Zhong, Chi Sun-Lin, Xu Wei-Hong
College of Resources and Environmental Sciences, Southwest University, Chongqing 400715, China.
Huan Jing Ke Xue. 2021 Mar 8;42(3):1545-1558. doi: 10.13227/j.hjkx.202005087.
Residual tetracycline antibiotics (TCs) in farmland soils with the application of livestock manure cause risks to the growth of vegetables and soil ecology. Here, pot experiments are carried out using through exogenous addition of different levels of oxytetracycline (OTC), tetracycline (TC), and chlortetracycline (CTC), to study the physiological toxicity, uptake, and transportation of TCs in lettuce. The subsequent degradation of TCs in soil was also evaluated along with analyses of soil enzyme activity and microbial population dynamics. The results showed that the biomass of lettuce decreased with application of TCs as well as the chlorophyll-, chlorophyll-, and carotenoid content. Consequently, net photosynthetic rates were inhibited, and SOD, POD, and CAT increased under the stress imposed by the TCs. With an increase in the level of TC application, uptake by lettuce plants increased while the bioconcentration and translocation factors decreased. When OTC, TC, and CTC in the soil were below 150 mg·kg, the health risk from the edible parts of lettuce was low (HQ<0.1). The TC degradation rate in different soils was ranked in the order of control soil > rhizosphere soil > bulk soil. The OTC degradation rates in the soils were significantly lower than for TC and CTC. TCs (150-1350 mg·kg) significantly inhibited urease and rhizosphere catalase activity in soil and reduced the number of soil culturable bacteria and fungi.
施用畜禽粪便的农田土壤中残留的四环素类抗生素（TCs）对蔬菜生长和土壤生态造成风险。在此，通过外源添加不同水平的土霉素（OTC）、四环素（TC）和金霉素（CTC）进行盆栽试验，以研究TCs在生菜中的生理毒性、吸收和转运。同时评估了土壤中TCs的后续降解情况，并分析了土壤酶活性和微生物种群动态。结果表明，随着TCs施用量的增加，生菜生物量以及叶绿素、叶绿素和类胡萝卜素含量均下降。因此，净光合速率受到抑制，在TCs胁迫下超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性增加。随着TC施用量的增加，生菜植株对其吸收增加，但生物富集和转运系数降低。当土壤中OTC、TC和CTC含量低于150 mg·kg时，生菜可食用部分的健康风险较低（危害商数HQ<0.1）。不同土壤中TC的降解速率排序为：对照土壤>根际土壤>非根际土壤。土壤中OTC的降解速率显著低于TC和CTC。TCs（150 - 1350 mg·kg）显著抑制土壤脲酶和根际过氧化氢酶活性，并减少土壤可培养细菌和真菌数量。
