恩诺沙星对土壤细菌数量及微生物生物量碳的影响

为了评价兽药恩诺沙星(Enrofloxacin,ENR)对土壤微生物的影响,采用平板计数法和熏蒸浸提法研究了不同含量恩诺沙星(wENR)对土壤细菌数量和土壤微生物生物量碳(MBC)含量的影响.结果发现,添加药物组细菌数量和土壤微生物生物量碳含量均低于对照组,且药物含量越高,细菌数量和土壤微生物生物量碳含量越低;较低含量的恩诺沙星(wENR<0.1μg·g-1,细菌数量;wENR<1μg·g-1,MBC)对细菌数量和微生物生物量碳含量影响不显著(与对照组比较,p>0.05),而较高含量的恩诺沙星(wENR≥0.1μg·g-1,细菌数量;wENR≥1μg·g-1,MBC)则影响显著(与对照组比较,p<0.05).以上结果表明恩诺沙星残留可显著影响土壤细菌数量和微生物生物量碳含量,进而可能影响土壤特性和土壤的一些生态过程。

Effects of Enrofloxacin on the Total Number of Bacteria and the Content of Microbial Biomass Carbon in Soil

The total bacteria number and content of microbial biomass carbon(MBC) in the soil samples treated with different doses of enrofloxacin(ENR)were measured by methods of plate count agar and fumigation extraction,respectively,to evaluate the effects of ENR on microbial communities in soil.Results showed that both the total bacteria number and the content of MBC in the exposure groups were lower than those in the control group.With the increase of concentrations of ENR,the total bacteria number and the content of MBC decreased gradually.There were significant(p<0.05) differences between the control group and the higher-dose groups(wENR≥0.1μg·g-1 for total bacterial number;wENR≥1μg·g-1 for MBC),while no significant(p>0.05) difference was found between the control group and the lower-dose groups(wENR<0.1μg·g-1 for total bacterial number,wENR<1μg·g-1 for MBC).The above results indicated that ENR residues could affect the total bacterial number and the content of MBC in soil significantly,which implied that ENR resides might influence the properties and the ecological processes of soil.