Analyzing The Harmless Process Of Organic Solid Waste Compost In Industry And Agriculture By Integrated Meta-omics

At present,there are three kind of major pollution which are come from industrial,agricultural and domestic.In China,tons of wastes derived from industrial and agricultural are produced every year.As is reported by Ministry of Agriculture,the production of livestock and poultry in China in 2016 was 3.8 billion tons.At the same time the annual output of sewage is 62 billion tons.as a by-product of sewage treatment the amount of sludge is a very huge which can not be underestimated.Animal husbandry and sludge contain a variety of pathogenic bacteria and antibiotic resistance genes(ARGs),and the efficient and environmental benign method is urgently needed.In this paper,we used integrated meta-omics to track the dynamic changes of microbial communities and their functions during the composting process.Combined with real-time PCR to track the dynamic changes of ARGs.Besides,environmental factor correlation analysis was used to find the relation between microbial communities and ARGs.In response to the above questions,the research carried out in this paper is as follows:1.The meta-omic study of cow manure compost communities revealed that high temperature of aerobic composting can realize the harmlessness of low-level antibiotic materials represented by cow dung.Using metagenomics three kinds of cow manure treatment processes.sediment tank treatment,physical desiccation treatment and composting treatment were compared.The results showed that thermophilic aerobic composting could effectively inhibit the growth of Proteobacteria and Bacteroides,which usually contain more pathogenic bacteria and drug-resistant bacteria.At the same time,the total abundance of antibiotic resistance gene can be reduced by 88%-98%through composting.The correlation analysis showed that Acinetobacter and Pseudomonas of Proteobacteria were potential hosts of antibiotic resistance genes.The decrease of total abundance of antibiotic resistance genes may related with the decrease of these two microorganisms during composting.2.The analysis of chicken manure composts showed that the antibiotic resistance genes in high content of antibiotic material could be reduced by composting represented by chicken manure,but further optimization was needed.Because of short digestion gut in chicken animials,most undigested nitrogenous substances along with a large amount of antibiotics intaked by chicken are discharged in vitro.In this paper,the composting process of chicken manure was dynamically tracked by the combination of high throughput sequencing and quantitative PCR.The results showed that thermophilic aerobic composting could effectively inhibit the growth of pathogenic microorganisms,but the reduction of antibiotic resistance genes was less efficient.Therefore,futher study is needed to achieve the effective removal of antibiotic resistance genes in high content of antibiotic materia represented by chicken manure by adjusting the materials and parameters of composting.3.Using integrated meta-omics including metagenomics and metaproteomics combined with quantitative PCR,the complex material compost represented by sludge were tracked.The results indicated that adding corncob residue in sludge compost can accelerate the innocent treatment process.The results showed that adding corncob residue in sludge compost can improve the growth of Actinobacteria and inhibit the growth of Bacteriodetes and Proteobacteria,which were analyzed by integrated meta-omics.At the same time,the removal efficiency of antibiotic resistance genes is as high as 98%,which is much higher than that of pure sludge compost.It means that adding corncob residue in sludge compost can accelerate the composting process.At the same time,the metaproteomics identified the main functional microorganisms in the sludge compost which are Planifilum,Thermopolyspora and Thermobifida.