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Optimizing Biogas Production from Municipal Solid Waste: A Comprehensive Analysis of Microbial Communities and Substrate Characteristics in Anaerobic Digestion Systems
1Bioproduct and Bioprocessing Technology Research Group, Faculty of Bioengineering and Technology, Universiti Malaysia Kelantan, Jeli Campus, Jeli 17600, Kelantan, Malaysia
2Department of Chemical Engineering, Jordan University of Science and Technology, P.O. Box 3030, lrbid 22110, lrbid, Jordan
*Email Address : yeeching@umk.edu.my
Abstract : The growing quantity of Municipal Solid Waste (MSW) poses significant environmental challenges and requires effective methods of waste treatment. This paper reviews anaerobic digestion (AD), a promising biological treatment effectively turning organic waste into biogas for a sustainable energy source with lessened waste accumulation emphasis on the important linkage between microbial community dynamics during AD and the physico-chemical properties of MSW substrates. The main findings indicate that the assessment of the microbial community has revealed the important role of certain bacterial and archaeal species in the digestion process for samples of pineapple and bread. The thick covering of peptidoglycan was visible in purple-coloured gram-positive bacteria, while bacteria with pink dye are gram-negative bacteria that have an outer membrane and a very thin peptidoglycan layer present in the sample of pineapple, while only gram-negative bacteria are present in bread, which is crucial for biogas production due to the breakdown of complex carbohydrates. The physical characteristics indicate that mixed bacterial populations are present in pineapple, whereas the presence of Gram-negative bacteria is found in bread. Spore-staining and growth on selective media for bread indicate that the water and bread mixture exhibited a higher concentration of pink-stained structures and moderate colony counts, whereas dried bread showed the opposite. The appearance of purple or blue coloration in certain streaked areas suggests that oxidase-positive bacteria are indeed present, and a positive catalase test is immediately recognizable by bubbling of hydrogen peroxide for pineapple. The acid production test confirms that pineapple releases acids into the medium, reflecting its natural acidity and potential role in food preservation, as well as its interaction with the microbial flora.
Keywords : municipal solid waste, anaerobic digestion, microbial activity, sustainable waste, biological treatment