A Microcosm Model for the Study of Microbial Community Shift and Carbon Emission from Landfills.

The landfill is an inexpensive way of municipal solid waste (MSW) management and contributes extensively to the total carbon budget and global climate change. Three landfills from two geographically distinct metro- cities of India were taken as model systems to create microcosms and study their physiochemistry, microbiology, and carbon emission. The microcosm experiments revealed that facultative anaerobic bacterial community showing the dominance in the beginning but with the progression of anoxia and anaerobic conditions, methanogenesis prevailed, resulting in a clear shift towards the abundance of methanogens especially the members of Methanosarcina, Methanocorpusculum, and Methanoculleus (70-90% of the total microbial population). Geochemical data showed a wide range of heterogeneity in landfills' composition located even in the same city. In past, greenhouse gas emission from landfills is mainly estimated using different models which lack accuracy. As limited information is available as of now, this study can elicit researcher interest for in-depth characterization of microbial diversity and carbon emission from landfills. The microcosm model presented in the current study is a robust and straightforward method of accurate estimation of amounts of different types of gases release from landfill. It can also be extrapolate for estimation of different gases release from actual landfill sites by setting the on-site experiments. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-021-00995-7. © Association of Microbiologists of India 2021.