Abstract: To accelerate the corn straw decomposition and promote straw waste recycling,the aerobic fermentation composting experiment was carried out using corn straw as the main raw materials. The physicochemical properties of windrow in different fermentation periods were measured by conventional methods,while the diversity analysis and species classification of microbial flora were carried out by metagenomic sequencing and bioinformatics method. The results of physicochemical properties showed that during the aerobic fermentation,the windrow temperature could rise quickly and maintain at above 55.0℃,the water content,organic matter and C/N ratio gradually decreased,and w (C)/w (N) was higher in building heap and in the first three turns and it dropped sharply at the last two turns,while the pH value and E4/E6 ratio decreased firstly and then increased. Metagenomic results showed that bacteria diversity existed in aerobic composting with corn straw. From the Simpson and Shannon index,the bacteria community diversity at the fifth turning(CS5)appeared to be the highest with subtle differences of the first three times(CS1,CS2 and CS3),while the diversity at the fourth turning(CS4)being the lowest. According to the species classification with OTU in 6 different fermentation periods,the species and abundances were different on phyla,orders and genera level,showing obvious community succession. Species classification results showed that Firmicutes, Proteobacteria,Bacteroidetes and Actinobacteria were the dominant groups on the phylum level.Bacillales,Clostridiales,Xanthomonadales,Thermoanaerobacterales,Rhizobiales,Pseudomonadales and Anaerolineales were main sharing groups on the order level. Povalibacter, Clostridium Ⅲ, Bacillus, Lysinibacillus, Ureibacillus, Pseudomonas and Chryseolinea were the main genera in the whole aerobic fermentation periods. Povalibacter belongs to Xanthomonadales of Proteobacteria,Clostridium Ⅲ and Lysinebacillus belong to Clostridiales of Firmicutes,and Chryseolinea belongs to Cytophagales of Bacteroidetes,they have not being reported to associate with lignocellulose degradation,it was expected to isolate new strains from these genera and accelerate the process of aerobic composting.

Key words: Corn straw (CS), Bacterial community diversity, Metagenomics, Aerobic fermentation, Different fermentation periods, Physicochemical properties

CLC Number: 

• Q939.96