Elimination Of Antibiotics And Resistance Genes In Livestock Manure

To study the effective method of removing residual antibiotics and ARGs(antibiotics resistance gene)in animal manure.And reduce the environmental pollution and human health hazards caused by manure,which was used as organic fertilizer to enter the environment.This study focused on the main residual antibiotics and ARGs in livestock manure.The main affecting factors to remove the antibiotics and ARGs in livestock manure were studied by solid-state incubation.And screening of antibiotics degrading bacteria and their application in livestock manure.To study the effect of exogenous added antibiotics degrading bacteria on the elimination of antibiotics and their resistance genes in livestock manure.Reducing the pollution of antibiotic and ARGs from microcosmic and macroscopic levels.And it has great guiding significance to effectively control the emissions of residual antibiotics and ARGs in livestock manure,and to reduce the risk of increased resistance in the environment.The main results were obtained as follows:(1)The study of solid-state incubation showed that the treatment of light,stirring,adding sawdust and prolonging the incubation time of high temperature could increase the removal efficiency of antibiotics in livestock manure.The relative abundance of tet and qnr in livestock manure could be significantly reduced by the treatment of dark,adding sawdust and prolonging the incubation time of high temperature,and the removal efficiency of qnr could be more than 66%.(2)Two strains of antibiotics degrading bacterium OTC-16 and SMD-FA were screened and isolated from the sludge in the aeration tank of the pharmaceutical factory.The results of HPLC assay showed that the two strains had the highest degradation rates of 97.4% and 57.9% at 10 days and 8 days respectively.It was identified that OTC-16 and SMD-FA belonged to the Arthrobacter and Alcaligenes,respectively.Named Arthrobacter sp.OTC-16 and Alcaligenes sp.SMD-FA.(3)Exogenous addition of antibiotics degrading bacterium can promote the removal of antibiotics and ARGs in livestock manure.Adding the mixed bacteria of OTC-16,SMD-FA and COD-1(Phanerochaete chrysosporium Burdsall)can significantly reduce the residual concentration of SM2(sulfamethazine)in pig and chicken manure,and the removal rate can reach 77.48% and 45.39%,respectively.Adding OTC-16,SMD-FA and COD-1 separately had a significant effect on reducing the concentration of oxytetracycline(OTC)and chlortetracycline(CTC)in pig manure,and the removal rate of COD-1 was as high as 80%.The addition of SMD-FA and COD-1 can also effectively remove the residues of OTC,CTC and TET(tetracycline)in chicken manure.The results of ARGs determined by fluorescence quantitative PCR(qPCR)showed that the addition of the mixed bacteria of these three bacteria can make the removal rate of qnr in pig manure reached 51.69%.Adding OTC-16 can reduce the relative abundance of sul?erm?tet in pig and chicken manure,but the effect is more significant in chicken manure,with removal rates of 41.03%,37.96%,62.79%,respectively.The addition of SMD-FA and COD-1 can effectively promote the decrease of the relative abundance of erm and qnr in pig manure.Therefore,it is presumed that the combined use of multi-functional microbes and the addition of microbial agents alone will have different effects on the degradation of antibiotics and the effects of the elimination of antibiotics resistance genes in different types of manure with different types of antibiotics and resistance genes.