Abstract
Eubacterial communities and bacterial pathogens occurring in the leachates collected from three full-scale landfills in mesothermal area of Japan were analyzed using DNA microarrays targeting approximately a thousand eubacterial and pathogen species/groups. The leachate samples showed almost similar eubacterial compositions with marginal variations. Comparison of the results with precedents suggested that the predominant eubacterial populations in the landfills may be generally similar in East and Southeast Asia, irrespective of the climate zone. Analysis of the bacterial pathogens showed that the three leachates included a total of 44 species/groups of bacterial pathogens and 26 species/groups including Francisella, a frank zoonotic pathogens causing a serious health risk, and other high-risk pathogens were commonly found. In addtion, the 2 leachate samples from the landfills, where organic wastes such as sludge and raw garbage were mainly disposed, had 15 specific pathogens. It was suggested that sludge can increase the variation of the pathogens occurring in landfill leachates. Overall, results of this study posed some insights into the underlying microbial ecology in the landfill and the possible microbiological health risks associated with the landfill leachate.
