SPATIAL VARIATION OF BACTERIAL COMMUNITY STRUCTURE AND DIVERSITY OF A LANDFILL IN BEIJING, CHINA, AS REVEALED BY HIGH THROUGHPUT SEQUENCING

摘要

Landfilling is the most widely used method to dispose solid waste in China. However, our lack of knowledge of the microbial community structure and diversity in landfill hampers our ability to use it more effectively. In this study, the microbial community structure and diversity of a landfill in Beijing, China, was revealed by high throughput sequencing, using Miseq platform. A total of 476330 sequences were yielded for the 10 samples collected at two independent wells with different landfilling depths (up to 16m). These sequences showed high amount of operational taxonomic units (OTU). 6070-13294 OTUs were detected for individual sample at the cutoff level of 3%, 98.1-99.8% of which were confirmed to be bacteria after the annotation. The alpha diversity indices changed greatly among all the samples and approximately 11m had the lowest value. Firmicutes (30-53%) was the most abundant phylum in all the samples, followed by Bacteroidetes and Proteobacteria. Redundancy analysis (RDA) results showed that 7 physicochemical characteristics, including moisture, pH, total organic carbon (TOC), total nitrogen (TN), chloride concentration, heavy metals (Cr and Cu) significantly affected the microbial community structure (P=0.037) and among them, pH appeared to be the most important parameter (P=0.001). Principal components analysis (PCA) showed that most samples from same wells could be clustered together, indicating that each sampling well was rather isolated and may form unique microbial communities depending on different waste compositions. Results of this study provided deeply insights into the spatial variation of bacterial community structure and diversity in land filled waste and discerned the relationships between bacterial community structure and physicochemical characteristics.