Characterization of methanogens from landfill samples: implications for sustainable biogas production

This case study aimed to isolate and identify methanogenic bacteria from landfill soil, mud, and leachate samples to assess their role in anaerobic digestion and biogas production. Anaerobic digestion involves the breakdown of organic matter by a diverse group of bacteria under oxygen-free conditions, resulting in the production of methane and carbon dioxide. The collected samples from the landfill were cultured in a modified mineral salt medium (MSM). Microscopic observations revealed distinct coccus and bacillus morphologies of the isolated methanogenic bacteria. Gas production experiments and substrate utilization studies identified two types of methanogens. <i>Methanosarcina</i> sp., which utilized acetate and methanol for methane production, and <i>Methanobacterium</i> sp., utilizing hydrogen and carbon dioxide, as well as acetate. Scanning electron microscope (SEM) analysis confirmed the different morphotypes of the isolated methanogens. The study findings demonstrated the presence of diverse methanogens in the landfill environment, contributing to anaerobic digestion and biogas production.