Untapped microbial wealth of Ethiopia: a systematic evidence-gap mapping of indigenous microorganisms for single-cell protein potential

Abstract

• Ethiopia harbors a rich but underexplored diversity of indigenous microorganisms with high SCP potential • Indigenous Ethiopian microbes offer sustainable protein solutions for food-insecure and climate-vulnerable regions • Traditional fermented foods serve as low-cost reservoirs of protein-rich, fast-growing microbial biomass • Microbial SCP from local strains can reduce dependence on land- and water-intensive animal proteins • Harnessing Ethiopia’s microbial biodiversity aligns SCP production with circular bioeconomy and SDGs The growing demand for sustainable protein has renewed scientific interest in Single Cell Protein (SCP) as a potentially resource-efficient bioprocess; however, its applicability in Ethiopia remains insufficiently evidenced. This study applies a systematic evidence-mapping and gap-analysis approach within a PRISMA-informed framework to evaluate Ethiopia’s SCP research landscape. The search identified multiple studies on microbial diversity and traditional fermentations but only one directly traceable Ethiopian SCP-related study, indicating a clear evidence limitation as the primary finding. Accordingly, all interpretations are categorized as (i) direct Ethiopian SCP evidence, (ii) indirect SCP-relevant microbial and fermentation traits, or (iii) global SCP benchmarks used strictly for contextual comparison rather than local validation. Indirect evidence from Ethiopian traditional fermented foods and beverages, including injera (sourdough-fermented teff flatbread), kocho (fermented enset starch), borde (low-alcohol cereal-based fermented beverage), shamita (spiced cereal-based fermented drink), cheka (fermented cereal beverage), tella (traditional cereal-based beer), and tej (honey wine), indicates the presence of diverse yeasts, lactic acid bacteria, and filamentous fungi with reported acid tolerance (approximately pH 3.5-5.0), carbohydrate fermentation capacity, and adaptation to low-cost agro-residues. While these traits suggest biological compatibility with SCP-relevant substrates, they do not constitute experimentally verified SCP production performance in Ethiopia. Similarly, reported biomass yields, protein enrichment levels, and process efficiencies from global SCP studies are referenced only as comparative baselines and not as locally achievable outcomes. Based on the synthesis of this indirect evidence, the findings cautiously suggest that future SCP research in Ethiopia may prioritize low-cost substrate utilization and potentially solid-state fermentation approaches; however, this remains a methodological inference rather than a demonstrated feasibility outcome. Overall, Ethiopian microbial diversity is better interpreted as an unverified but potentially relevant resource base, and the study establishes a structured, evidence-graded research gap rather than confirming SCP production readiness.