Recent Advances in Sustainable Yeast-Based Single-Cell Protein Production from Renewable Substrates Using Engineering Approaches

Yeast-based single-cell protein (SCP) has emerged as a promising sustainable protein source due to its high protein content, favorable nutritional profile, and ability to utilize renewable feedstocks. The conversion of food-processing wastes, agricultural by-products, and one-carbon substrates into protein-rich biomass supports waste valorization and circular bioeconomy strategies. However, efficient utilization of these diverse feedstocks remains challenging due to variations in substrate composition and microbial metabolic capacity. Recent advances in metabolic engineering, cell wall engineering, adaptive laboratory evolution, random mutagenesis, and fermentation optimization have improved substrate utilization, biomass formation, and protein accumulation in yeasts. These developments have expanded the potential applications of yeast-based SCP in protein supplements, meat products, flavoring agents, and animal feed. This review provides a comprehensive overview of yeast species for SCP production, renewable feedstock utilization, engineering approaches for enhancing biomass and protein accumulation, and the emerging applications of yeast-based SCP in sustainable food and feed systems.