The Research Of Role Of Microbial Agents In Organic Waste Composting And Their Mechanisms

With the development of husbandry, the accumulating amount of organic waste is increasing and it makes environmental pollution more and more serious.Composting treatment is one of the main technologies to achieve volume reduction, harmless treatment and reutilization of organic waste.But because of fermentation cycle long, innocuous level and fertility low, the traditional composting way and technology can't adapt to the requirement of modern agriculture. Therefore, It is of very important theoretic and practical significances that exploring the principles and methods of accelerated fermentation. This paper studied the effect of three different microbial agents on physicochemical property and maturity index during composting. Meanwhile, the change of organic matter content which are distributed in different molecular weight intervals was studied using GPC technology. In this base, the change of fungi and bacteria community in different composting stages under EM and QL treatments was studied using modern molecular biology technique(DGGE). The results show as follows:⑴Three microbial agents were beneficial to promote the rapid decomposition of compost ,shorten composting cycle and improve the quality of compost. The heating speedy was fastest under EM treatment and the composting temperature was highest under QL treatment. QL had the most significant influence on physicochemical property and the second was CH. Excepting control, the content of organic matter was highest under EM treatment and the lowest was CH treatment. The GI of composting was significantly improved and the T value,E4/E6 were significantly reduced by inoculating QL microbial agent. ⑵GPC studies showed that microbial agent treatment could promote the transformation of organic matter, accelerate the decomposition of macromolecular organic matter. During compost, the content of microm- olecular organic matter reduced gradually and the micromolecular organic matter content increased gradually. But at the same stage of composting, macromolecular organic matter content in microbial agent treatment was significantly lower than in control.⑶PCR-DGGE studies showed that there were not the same number of electrophoretic bands, bands migrated location, the strip edge bands and band intensity under different treatments and different periods, indicating that QL , EM treatment significantly affected the microbial community in composting. Microbial agent treatments decreased the similarities of fungi and bacterial community compared to the control. QL and EM treatments increased the average bacterial richness index by 22.73% and 5.43%, the average fungal richness index increased by 43.28%, 28.36%, and the average bacterial shannon's index increased by 14.32%, 4.02%, the average fungal shannon's index increased by 65.52%, 34.17%. In contrast, QL microbial agent was better than EM microbial agent.