Chaka, Osano Aloys and Bakari2024-01-242024-01-242019-09https://www.rsisinternational.org/jour nals/ijrias/DigitalLibrary/Vol.4&Issue9/ 60-67.pdfhttps://repository.nrf.go.ke/handle/123456789/355Biogas production at low temperature regimes isannoyingly slow and yields low biogas volumes. Most biogassupplements are expensive and substrate-specific. The effects oftwo bio-catalysts Saccharomyeces spp. and Acanthaceae spp. andan inorganic catalyst ferric oxide on biogas production using cowdung slurry was investigated. 1.5L batch anaerobic digesteroperating in unstirred cryo-mesophilic temperature regime of20.0 -24.5 0C were utilized. The substrate underwent mildsynergistic pre-treatment by steaming with 1% sodiumhydroxide solution. The alkalinity and volatile acids of thesubstrates were insignificantly perturbed by inclusion of theadditives. Additives Saccharomyeces spp. and Acanthaceae spp.stabilized digestion temperature while ferric oxide stabilized pHdrifts. The overall biogas yields produced in the 100-dayretention period were in the order of 4615ml (990.34ml/g-Volatilesolids) for ferric oxide, 2335ml (494.08ml/g-Volatile solids) forSaccharomyeces spp., 1750ml (328.94ml/g-Volatile solids) forAcanthaceae spp. and 1030ml (212.37ml/g-Volatile solids) for thecontrol sample. Use of these additives would thus optimize biogasproduction in cold countries.enMasinde Muliro UniversityArticle