典型四环素类抗生素对土壤微生物及植物生长的影响

四环素类抗生素(TCs)在畜禽养殖中的大量使用甚至滥用,导致其在动物粪便中高浓度残留。随着畜禽粪便有机肥的农田施用,TCs持续进入土壤并且不断累积,由此带来的土壤生态危害和健康风险值得关注。以四环素(TC)、土霉素(OTC)为研究对象,采用室内培养试验法,考察2种典型TCs对土壤微生物、酶活性的影响及对植物生长的毒性作用。结果表明,低浓度TC和OTC作用下,土壤细菌和真菌数量即显著降低,土壤细菌较真菌对TCs的污染更为敏感。除TC对土壤酸性磷酸酶和OTC对土壤过氧化氢酶活性主要表现为激活作用外,总体上TC、OTC作用后土壤酶活性呈低浓度促进、高浓度抑制的变化趋势。80 mg·L~(-1)的TC、OTC暴露下,绿豆芽芽伸长被显著抑制,并且随着抗生素浓度的增大,绿豆芽伸长抑制率大幅升高。相同浓度、相同暴露时间条件下的TC对绿豆芽伸长的毒性大于OTC。

Effects of Typical Tetracycline Antibiotics on Soil Microorganisms and Plant Growth

Tetracycline antibiotics (TCs) were widely used and even abused in livestock and poultry breeding which led to high levels of residue in animal faeces. With the application of organic manure from livestock and poultry in farmland, TCs entered the soil and accumulated continuously. Thus the soil ecological hazards and health risks are worthy of attention. In this study, the effects of two typical TCs, i.e., tetracycline (TC) and oxytetracycline (OTC), on soil microbial, enzyme activities and plant growth were investigated by laboratory culture test. The results showed that the amount of soil bacteria and fungi was significantly reduced in TC and OTC low concentration treatments, and soil bacteria were more sensitive to TCs pollution than fungi. Except the active effect of TC on soil acid phosphatase and OTC on soil catalase, the soil enzyme activities generally showed a trend of low promotion and high inhibition in TCs treatments. After the exposure to 80 mg L^?1 of TC and OTC, the elongation of mung bean sprouts was significantly inhibited, and the inhibition rate of elongation significantly increased with the increase of antibiotic concentration. The toxicity of TC to the elongation of mung bean sprouts was greater than OTC at the same concentration and exposure time.