The Microbial Process Of Garden Waste Decomposition And Screening Of Cellulose-degrading Microbe

Recently with the increasing of China’s urban landscape area, there is a gradual increasing of garden waste generation. How to effectively deal with and reuse them has brought to the forefront of many scholars. As the garden waste contains a high rate of lignin and cellulose, it’s not a simple thing to deal with them. Well, after a pile of compost treatment they can be used as plant medium and partly substitute for peat substrate after proportion. The garden waste decomposition processing produce flowers and trees plant medium is a good way to reuse garden waste. In order to promoting the process of corrosion of garden waste and producing high quality plant medium. This paper systematicly studies the decomposition process and the obtained reults are as follows:This research began at December2011, the raw material of composting were leaves and branches. During the process the changing of physicochemical property law were as follows: for the two decomposting pile the changing trend of temperature are similar, the composting system of branches need more time to decompost and the highest temperature it reached was lower than the composting system of leaves. The total N and effective P and K of the two composting system were showed uptrend, and for all the three indexes the composting system of branches were higher the other system. During the composting progress the pH changed from lower than6to higher than8. The microbial flora during composting of garden waste was studied using plate culture. The quantity of culturable bacteria biomass was in the order of108cfu/g, fungi was in the order of105cfu/g to106cfu/g. The number of bacteria increased at first and reached to the peak at the middle temperature stage, entering the high temperature stage the number of bacteria began to fall; after that with the falling of temperature the number of bacteria rose again. Different from bacteria, the number of fungi drop rapidly at the beginning of composting, then at the high temperature stage its number picked up and reached to the top and at the later stage of high temperature stage its number fall again. At the end of composting the number of fungi began to rose again. Sequencing analysis based on the partial16S rDNA sequences and ITS sequences indicated that isolates were mostly clustered into Fimicutes, Actinobacteria, Alphaproteobacteria, Gammaproteobacteria, Betaproteobacteria and Bacteroidetes. Fimicutes and Gammaproteobacteria were both dominant bacteria. The similarity of6strains were lower than97%. The type of fungi were very rich, Penicillium, Chaetomium and Aspergillus were dominant fungi.8strains of bacteria and37strains of fungi were isolated by culturing on CMC-Na Congo red plate medium.According to the activity of Cx, we screened1strain of bacteria, the cellulose enzymes activity (Cx) was49.75U/mL. Based on16S rDNA sequence the bacteria was Bacillus subtilis.3strains of fungi were also screened, the cellulose enzymes activity (Cx) was more than100U/mL. According to ITS rDNA sequence the fungi were Penicillium radicum, Aspergillus terreus and Corynascus sepedonium.