Ruminations on sustainable and safe food: Championing for open symbiotic cultures ensuring resource efficiency, eco-sustainability and affordability.

Microbes are powerful upgraders, able to convert simple substrates to nutritional metabolites at rates and yields surpassing those of higher organisms by a factor of 2 to 10. A summary table highlights the superior efficiencies of a whole array of microbes compared to conventionally farmed animals and insects, converting nitrogen and organics to food and feed. Aiming at the most resource-efficient class of microbial proteins, deploying the power of open microbial communities, coined here as 'symbiotic microbiomes' is promising.