Can Closed-Loop Microbial Protein Provide Sustainable Protein Security Against the Hunger Pandemic?

Increasing demand for animal-sourced protein is a major driver of the food system’s transgression of the safe environmental operating limits known as planetary boundaries. Microbial proteins are being explored as an alternative to provide sustainable protein security within the planetary boundaries. Here, a design and optimization framework was developed for a closed-loop process in which bioenergy and nutrients are recovered from microbial protein production wastewater. The environmental benefits of a global transition from animal-sourced beef protein toward closed-loop microbial protein with integrated resource recovery was analysed. Microbial protein has a shorter production life cycle than animal-sourced beef protein, thus offering a scalable technology solution to protein security with substantially mitigated environmental impacts. Our results demonstrate the value of environmentally favourable closed-loop food systems to meet projected 2050 protein demand while maintaining food system operations within the safe environmental limits.