Assessment of Alternative Energy Sources and the Role of Microorganisms in the Biodegradation of Domestic Wastes in Nigeria
Abstract
The aim of this study was to demonstrate that biogas can be generated from domestic kitchen waste and to identify the bacterial succession involved in its anaerobic decomposition. A total of 10 kg of kitchen waste was processed into a slurry by maceration in a laboratory mortar, using 21 litres of tap water. The resulting slurry was introduced into a batch-system biodigester constructed from a 25-litre plastic container insulated with Flexi-glass. The biodigester featured two outlet pipes: one on the lid for gas collection and another at the base for sampling.
The setup was maintained at room temperature for 12 weeks. Metagenomic analysis of the slurry was conducted using Next Generation Sequencing (NGS). DNA was amplified via automated PCR cycles and sequenced using the Genome Sequencer FLX System (454 Life Sciences, Roche Applied Science). Sequence alignment and analysis were carried out using Vecton NTI Suite 9 (InforMax, Inc.), and the resulting sequences were compared with those in GenBank using BLAST analysis via CLO Bio software.
Biogas production was assessed after three weeks using a commercially available MULTIRAE PGM 50 gas detector. The primary components of the biogas generated were methane (62%), carbon dioxide (22%), ammonia (2%), hydrogen sulfide (1.4%), and water vapour (trace levels).
Microorganisms identified in the biodegradation process included Lactobacillus rapi strain LA1165, Clostridium tyrobutyricum, Ralstonia pickettii, and Methanoculleus species. These findings confirm that biogas can be effectively produced from kitchen waste. Utilizing such biogas as an alternative fuel source for cooking can contribute to reducing greenhouse gas emissions and improving respiratory health, thereby addressing climate change and environmental sustainability.
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References
Ahring, B. K. (1995). Methanogenesis in thermophilic biogas reactors. Antonie van Leeuwenhoek, 67, 91–102.
Andreas, S., Thomas, B., Naryttza, N. D., Michael, N., & Rudolf, E. (2008). The metagenome of a biogas-producing microbial community of a production-scale biogas plant fermenter analysed by the 454-pyrosequencing technology. Journal of Biotechnology, 136, 77–90.
Anunpultikul, W., & Rodtong, S. (2004). Laboratory scale experiments for biogas production from cassava tubers. The Joint International Conferences on "Sustainable Energy and Environment" (SEE).
Bayer, E. A., Belaich, J. P., Shoham, Y., & Lamed, R. (2004). The cellulosomes: Multi-enzyme machines for degradation of plant cell wall polysaccharides. Annual Review of Microbiology, 58, 521–554.
Deppenmeier, U., Müller, V., & Gottschalk, G. (1996). Pathways of energy conservation in methanogenic archaea. Archives of Microbiology, 165, 149–163.
Hughes, K. L., & Christy, A. (2003). Bioreactor landfills. In Encyclopedia of Agricultural, Food, and Biological Engineering (pp. 104–107). Marcel Dekker, Inc.
Klocke, M., Ahnert, P., Mundt, K., Souidi, K., & Linke, B. (2007). Microbial community analysis of a biogas-producing completely stirred tank reactor fed continuously with fodder beet silage as mono-substrate. Systematic and Applied Microbiology, 30, 139–151.
Lucas, E. B., & Bamgboye, A. I. (1998). Anaerobic digestion of chopped water hyacinth. Nigerian Journal of Renewable Energy, 6(1), 62–66.
Reeve, J. N. (1992). Molecular biology of methanogens. Annual Review of Microbiology, 46, 165–191.
Ryan, M. P., Pembroke, J. T., & Adley, C. C. (2007). Ralstonia pickettii in environmental biotechnology and applications. Journal of Applied Microbiology, 103(4), 754–764.
Weiland, P. (2003). Production and energetic use of biogas from energy crops and wastes in Germany. Applied Biochemistry and Biotechnology, 109, 263–274.
Zuru, A. A., Saidu, H., Odum, E. A., & Onuorah, O. A. (1998). A comparative study of biogas production from horse, goat and sheep dungs. Nigerian Journal of Renewable Energy, 6(1), 43–47
