土霉素污染对土壤生物学性质影响的初步研究

为了解随粪肥进入农田中的土霉素对土壤生物化学性质产生的可能影响，采用实验模拟方法研究了土霉素污染对土壤微生物生物量碳、土壤酶活性及微生物组成的影响。结果表明，土霉素污染对土壤细菌、放线菌数量和微生物总量均有一定的抑制作用，随土霉素污染程度的提高抑制作用也有所增强；但土霉素污染对真菌的作用较为复杂，一般是低浓度时有促进作用，高浓度时有抑制作用。低量土霉素污染对土壤脲酶和中性磷酸酶活性均无明显的影响，但高量的土霉素污染对土壤脲酶活性起抑制作用。土霉素对土壤微生物生物量碳的影响因土壤类型、土霉素加入量和培养时间不同有所差异。土霉素污染对土壤生物化学性质的影响主要发生在土霉素进入土壤的初期，随着时间的增加，影响逐渐减弱和消失；

Effects of Oxytetracycline Pollution on Soil Biological Properties

Antibiotics used in livestock production may be present in manure and slurry as the parent compound and/or metabolites. Soils may therefore be exposed to these antibiotics due to the application of animal manure to agricultural land. In order to understand the potential impact of antibiotics on soil biological properties, oxytetrycycline （C22H24N2O9,OTC）, an antibiotic that was widely used to prevent animal infectious diseases in China, was selected to characterize its effects on numbers of soil microorganisms, micro-biomass carbon, and enzymes by laboratory studies. The results showed that the OTC pollution of soils could inhibit numbers of bacteria, actinomyces, and total microorganisms. The numbers of the microorganisms decreased as the concentration of oxytetrycycline in the soils increased. The effect of the OTC on fungi varied with concentration of the antibiotic. Low concentration of the OTC could stimulate the growth of fungi, while high concentration of the OTC had the inhibitory effects on the growth of fungi. Low concentration of the OTC in soils had no significant effects on soil neutral phosphotase and urease activities. However, high concentration of the OTC could inhibit soil urease activity. The effects of the OTC on soil microbiomass carbon varied with soil type, concentration of the OTC added, and incubation time. The influences of the OTC on soil biological properties occurred in initial stage of the antibiotic addition, and declined with increasing the incubation time. The decreased effects might be due to strong adsorption of the soils to the OTC and degradation of the antibiotic in the soils.