Formulating Microbiological Culture Media using Domestic Food Products

Abstract

This study investigated the prospects of formulating microbiological culture media from domestic food products, specifically garri and offor, as low-cost alternatives to conventional commercial media for the enumeration, cultivation, and characterisation of bacteria and fungi. Four locally formulated media were prepared: Peptone Garri Agar (PGA), Peptone Offor Agar (POA), Potato Dextrose Garri Agar (PDGA), and Potato Dextrose Offor Agar (PDOA). Open-air sampling was carried out at four locations within Rivers State University, namely the Biology Laboratory garden, the Faculty of Science car park, the Biological Science car park, and the Biology Office car park. Exposed plates were incubated at 37°C for 24 hours for bacteria and at ambient temperature for 3–5 days for fungi, after which colony counts were recorded and discrete isolates were characterised using standard microscopic, cultural, and biochemical procedures. A total of eight (8) bacterial genera (Bacillus, Staphylococcus, Leuconostoc, Micrococcus, Lactobacillus, Klebsiella, Proteus, and Pediococcus) and five fungal genera (Penicillium, Aspergillus niger, Fusarium, Mucor, and Rhizopus) were isolated and identified on the locally formulated media. The highest bacterial load of 9.4 × 10³ CFU was recorded at the Science car park, while the highest fungal load of 3.0 × 10² CFU was recorded at the Faculty of Science car park. Staphylococcus sp. was the most frequently occurring bacterial isolate (27.27%), while Penicillium spp., Rhizopus spp., and Aspergillus niger were the most frequently occurring fungal isolates, each accounting for 30% of fungal recoveries. These findings indicate that the locally formulated garri- and offor-based media supported appreciable growth, enumeration, and differentiation of a broad diversity of environmental bacteria and fungi. The study concludes that domestic food products, particularly garri and offor, show potential as affordable, locally sourced substrates for microbiological culture media formulation, offering a possible approach to the recurring shortage and high cost of imported commercial media in Nigerian university and public health laboratories. Further comparative and optimisation studies are recommended to standardise the formulations and validate their performance against a wider range of clinically and environmentally significant microorganisms.