Physicochemical factors and dominant bacterial groups affecting antibiotic degradation in chicken manure aerobic compost
Taking chicken manure as raw material,the influence of EM microbial agent on the key dominant bacterial groups controlling the degradation of antibiotics were studied in the compost simulated by adding oxytetracycline and tylosin to simulate antibiotic residues.The objective is to explore the bioenhancing mechanism of antibiotic removal in aerobic composting.The experiment was carried out consisting of four treatments,that is,OCK(oxytetracycline),OTK(oxytetracycline+EM bactericide),TCK(Tylomycin+EM bactericide),TTK(Tylomycin+EM bactericide.The amounts of added antibiotics and EM microbial agent were 100mg/kg and 5％of the total mass,respectively.The results showed that the residue of antibiotics had little effect on compost maturation,and all treatments could reach the maturation standard.The composting temperature exceeded 60 ℃ for more than 6days,the pH value ranged from 8.5 to 9.0,the EC was 3～3.5mS/cm.The removal of both antibiotic mostly happened at high temperature stage,When the removal rates of antibiotics were correspondingly OCK:71.63％,OTK:76.40％,TCK:93.86％,TTK:92.95％.The EM microbial agent accelerated the degradation of antibiotics,especially for oxytetracycline,which could increase the degradation rate of oxytetracycline by 5 times and that of Tylomycin by 2.24 times.At mature stage,aerobic compost effectively removed the antibiotic residues,with higher antibiotic removal rates of four treatments,OCK 89.97％,OTK 91.32％,TCK 99.99％,TTK 99.99％.pH value is identified as a key physicochemical factor affecting the degradation of oxytetracycline and tylomycin,which was negatively correlated with the content of both antibiotics,so proper adjustment of the pH was conducive to faster degradation of antibiotics.The dominant bacterial groups conducive to oxytetracycline degradation mainly include Planifilum,Thermobifida,Bacillus and Paenibacillus,with Relative abundance(RAs)were 0.24％～8.76％,2.70％～10.91％,11.38％～26.16％,and 1.95％～4.56％.While Thermobacillus and Bacillus was helpful for degradation of Tylomycin with RAs were 7.19％～39.09％and 41.70％～44.29％,respectively.Bacillus can promote the degradation of oxytetracycline and tylosin.
aerobic compostantibioticbiological enhancementdominant bacteriak community
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维普
