Fueling the protein transition: Can waste-derived ethanol enable efficient and high-quality microbial protein production?

Meeting the protein needs of a growing population will require significant resources. In this context, microbial protein (MP) offers a nutritious and versatile protein source from recovered resources. This meta-analysis of over 100 studies examines the efficiency and nutritional quality of MP production using ethanol. Ethanol, a feedstock derived from CO2 and biological waste, is used by various microorganisms, and has an established role in the food sector. Results show that ethanol-based MP production is technically feasible for food applications, reaching biomass concentrations of 14–230 g/L and productivities of 11–13 g/L/h. The protein content of MP correlates with productivity, and the nutritional quality of ethanol-grown MP matches common sources like pork and tofu. Lastly, operational choices affect the techno-economic feasibility of using waste-derived ethanol and other recovered resources. This meta-analysis highlights the potential of ethanol-grown MP, though further research is needed to close existing knowledge gaps.