ASSESSMENT OF MICROBIOLOGICAL MEDIA FORMULATED FROM FOOD WASTE

ABSTRACT This study assessed the potential of guinea corn chaff and millet chaff, by-products of Kunu production, as components for formulating microbiological culture media. Fresh samples of guinea corn and millet chaff were collected from Yelwa and Gwallameji markets in Bauchi, processed, and formulated into culture media using varying agar concentrations (0.5g, 1.0g, and 1.5g per 100mL). The media were evaluated for their ability to support the growth of Staphylococcus aureus ATCC 25923 and Aspergillus niger using standard microbiological techniques. Optimization studies revealed that 1.0g agar concentration provided optimal gelling strength with firm but flexible consistency, supporting well-defined discrete colonies with good growth rates. The formulated media successfully maintained the distinctive morphological characteristics of test organisms, with S. aureus forming circular, golden to pale-yellow colonies (4.0-4.5mm diameter) and A. niger producing irregular, dark grey to black cottony colonies (3.7-4.2mm diameter). Colony count analysis demonstrated that while commercial media yielded higher microbial counts (Nutrient Agar: 125 CFU/ml for S. aureus; PDA: 83 CFU/ml for A. niger), the formulated media showed comparable performance with guinea corn media supporting 71-84 CFU/ml for S. aureus and 57-62 CFU/ml for A. niger, while millet chaff media yielded 63 CFU/ml for S. aureus and 67 CFU/ml for A. niger. The study demonstrates that guinea corn and millet chaff can serve as cost-effective, sustainable alternatives to conventional culture media, particularly suitable for resource-constrained laboratory settings. These findings contribute to waste valorization, environmental sustainability, and accessible microbiological testing while maintaining acceptable standards for microbial cultivation and identification.