Effects Of Biochar On Diversity Of Microbial Community And Antibiotic Resistance Genes During Conposting

Antibiotics are widely used by livestock industry,which may induce ARGs in animal gut microbes,thus animal manure is considered to be an important reservoir of antibiotics and ARGs.Livestock and poultry manure are important fertilizer resources and ARGs are expected introduced by animal waste derived fertilizer.ARGs are likely to spread by horizontal gene transfer between the different microbial propagation,which may pose a serious threat to human health.Therefore,the fertilizer preprocessing to remove before fertilization to reduce ARGs is of great significance to human health.This dissertation studied biochar with enormous specific surface area and chicken manure of the antibiotics frequently used as research objects,by adding different proportions of biochar,wheat straw and chicken manure.Through the analysis of physical and chemical properties,enzyme activity,the influence of the microbial community diversity,then further investigate biochar impact on the abundance of ARGs,and determine the relationship between environmental factors and ARGs during composting,the main results are as follows:(1)After 26 days of compost,all the processing of pile body temperature 50 ? above are maintained in 5 days(or above),satisfy the standard of disposal.Biochar(which increases the temperature of the heat of the heap)increases the temperature of the high temperature and benefits mineralization of organic matter.The addition of biochar increased NH4+ significantly during the thermophilic period,and increased NO3--N 16.7 ~ 69.0% at the end of compost.When the compost was over,bio-Cu and bio-Zn were reduced by 2.3% ~ 13.0% and 10.6% ~ 24.2% respectively compared with the control treatment.At the end of the compost,the effect of biochar on the activity of cellulose enzyme and urease activity has been reduced.(2)By Biolog analysis showed that the thermophilic period,treatments with biochar application can significantly increase microbial activity in thermophilic period,and with the increase of adding ratio,the higher microbial activity;When the proportion of biochar is too high(20%)in cooling period,it is harmful to the improvement of microbial activity.There was no significant difference in the treatment of the maturation period.The addition of high proportion of biochar(BC10 and BC20)reduces the microbial diversity of high temperatures.Principal component analysis showed that add biochar changed the microbial community structure in the process of compost,BC10 treatment effect is more significant,the differentiation of carbon source mainly to sugars,amino acids and carboxylic acid.(3)This study shows that after 26 days of composting,most ARGs are effectively removed.CK,BC5,BC10,and BC20 resistance genes(except for sul1)declined 0.85,1.05,1.08,and 1.15 orders of magnitude.Temperature is the most important environmental factor in all environmental factors.Biochar reduces the 8/12 tetC,tetG,tet W,tetX,sul2,drfA1,drfA7,ermB relative abundance,different proportion of biochar to tetG,tet W,tet X,sul2,drfA1,have no obvious effect on ermB,treatment with 10% biochar had the most effective efficiency on removal of tetC,drfA7.As a result,10% of biochar may be a suitable proportion to remove the resistance genes from chicken manure.