Geographic and environmental sources of variation in bacterial community composition in a large-scale municipal landfill site in China

Little is known regarding how bacterial communities assemble at landfill, as well as how the environment shapes the composition of bacterial community. In this study, up to 42 refuse samples from a large-scale landfill in China were physicochemically and phylogenetically investigated. 16S ribosomal RNA (rRNA) gene-based Illumina MiSeq sequencing (nine samples) revealed that representatives of Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Firmicutes, and Bacteroidetes were dominant in the refuse samples, which was similar to a previous study on landfill leachate by using 454 pyrosequencing. Although 741 operational taxonomic units (OTUs) were detected across all nine samples, 6 of these OTUs were detected in all of the data sets, suggesting difference between bacterial community structures. Geographical differences between the samples, irrespective of depths, were revealed by a principal component analysis (PCA) based on the terminal restriction fragment length polymorphism (TRFLP) profiles of 42 refuse samples. Redundancy analysis (RDA) suggested that environmental heterogeneity (pH, landfilling ages, and depths) and the abundance of bacteria (represented by 16S rRNA gene copy numbers) were the main drivers shaping the bacterial community structure.