The succession pattern of bacterial diversity in compost using pig manure mixed with wood chips analyzed by 16S rRNA gene analysis

Abstract

The pig manure mixed with wood chips and formed compost by means of fermentation. We found that the protease activity, organic matter content and ammonium nitrogen concentration were higher in the early stage of composting. Meanwhile, the urease activity was highest in the high temperature period. The carbon to nitrogen ratio of the compost decreased continuously with fermentation. The dynamic change in the composition of bacterial overtime in the compost of a 180 kg piles were explored using microbial diversity analysis. The results showed that the microbial species increased with the compost fermentation. At the early stage of composting, the phyla of Firmicutes and Actinomycetes were dominant. The microbes in the high temperature period were mainly composed of Firmicutes and Proteobacteria while the proportion of Bacteroides was increased during the cooling period. In the compost of maturity stage, the proportion of Chloroflexi increased, becoming dominant species with other microorganisms including Firmicutes, Proteobacteria, Bacteroides, Chloroflexi but not Actinomycetes. Bacteria involved in lignocellulose degradation, such as those of the Thermobifida, Cellvibrio, Mycobacterium, Streptomyces and Rhodococcus, were concentrated in the maturity stages of composting. Through correlation analysis, the environmental factors including organic matter, ammonium nitrogen and temperature were consistent with the succession of microbial including Rhodocyclaceae, Anaerolineaceae, Thiopseudomonas, Sinibacillus and Tepidimicrobium. The change of urease activity and carbon to nitrogen ratio corresponded to microbial communities, mainly containing Anaerolineaceae, Rhodocyclaceae, Luteimoas, Bacillaceae, Corynebacterium, Bacillus, Anaerococcus, Lactobacillus, Ignatzschineria, and Bacillaceae.