Waste-derived single-cell protein in Nigeria: current status, translational gaps, and development opportunities

Abstract

Abstract This review examines the current state of single-cell protein (SCP) research based on waste-derived substrates in Nigeria, with emphasis on substrate choice, microbial systems, bioprocess strategies, performance reporting, and prospects for commercial translation. Evidence from Nigeria-focused studies shows that a broad range of locally available waste streams, particularly those containing cassava peels, yam peels, cereal byproducts, fruit wastes, and sawdust, can support microbial growth and protein content improvement when yeasts, filamentous fungi, bacteria, and, to a lesser extent, mixed cultures are used. Most studies clearly demonstrate biological feasibility, and several also report reductions in the levels of fibre, cyanide, or other antinutritional factors. A relatively small number of studies extend to short-term feeding trials, providing early support for feed-oriented application. Despite this promise, the Nigerian literature remains dominated by laboratory-scale studies based largely on simple solid-state or batch submerged fermentation systems. Important translational elements, including strain robustness, process standardisation, downstream recovery, local techno-economic assessment, and regulatory preparation, remain poorly developed. Inconsistently reported protein-related outcomes have been reported, with many studies relying on crude or soluble protein measurements without a deeper assessment of amino acid quality, digestibility, or product safety. As a result, a clear gap persists between demonstrated laboratory feasibility and market-ready SCP production.