| Adding exogenous additives in the process of harmless treatment of livestock and poultry manure can improve the treatment efficiency and fertilizer efficiency.The aim of this paper is to study harmless feces of livestock and poultry,the treatment efficiency can be improved by adding exogenous substances.The appropriate washing agent was screened,high efficiency cellulose degrading microorganisms.After harmless treatment analyze the change of microbial diversity.The main conclusions are as follows:(1)Chitosan,EDTA,citrate sodium was added in the harmless treatment of livestock and poultry feces to leach them.The contents of Cu,Zn,Pb and Cd in the eluent were determined and screen the best eluent.Experimental results show that EDTA has the strongest leaching ability in the removal of Cu,Pb,Cd.After five hours of leaching,the total removal rates were 33.67%,54.66%,58.73%.Chitosan had the strongest leaching ability in the removal of heavy metal Zn,and the total leaching rate reached 44.14%.According to the analysis of the leaching speed,chitosan showed obvious advantages in the first two hours of leaching,and the removal rates of Cu,Zn,Pb and Cd reached 21.45%,39.51%,42.79% and 40.53%.In conclusion,chitosan is superior in rapid leaching and EDTA is superior in total leaching amount.In process production,two leaching agents can be combined to achieve better leaching effect.(2)Cellulose degradation bacteria has a good application prospect in the process of harmless treatment.The X-3 strain with strong cellulose degradation ability was isolated by Congo red medium.The results of morphological identification showed that baculobacter spores were sporty;The results of physiological and biochemical analysis showed that both methyl red test and citrate utilization were positive.The contact enzyme was negative.The oxidative fermentation test showed the oxidative type.Among them,5% salinity showed the best growth rate;Molecular identification of the X-3 strain was carried out,and the amplified sequence was sequenced.The obtained sequence length was 583 bp.BLAST tool in NCBI database was used for sequence comparison and phylogenetic trees were constructed with MEGA 7.0.Combined with morphological identification and physiological and biochemical detection results of the bacteria,it was preliminarily determined that strain X-3 was stenotrophomonas maltophilia.(3)The V3-V4 region of 16 SrDNA was sequenced using high-throughput sequencing technology to compare the changes of microbial diversity after harmless treatment of livestock and poultry feces with different exogenous additives.Alpha diversity analysis showed that the simultaneous use of antibiotic-degrading bacteria and cellulose degrading bacteria increased the species richness of group T3,indicating that the habitat was more suitable for the simultaneous survival of multiple microorganisms and the harmless treatment after composting had the best effect.At the phylum classification level,a total of 38 phylum were detected,among which proteobacteria accounted for a significant advantage(41.3610%~45.0427%),followed by bacteroidetes,gemmatimonadetes and actinobacteria.At the level of genera classification,a total of852 genera were detected,among which the unclassified genera and the gemmatimonas were the obvious dominant genera.At the same time,the existence of chloroflexi and actinobacteria also indicates that livestock and poultry manure can not only provide fertilizer efficiency,but also purify soil pollution,degrade pesticide residues and show advantages in resource utilization. |
