Robust, Scalable Standardized Two-Stage Fermentations using Dynamic Metabolic Control

We have developed a robust and generalizable two-stage fermentation process which decouples microbial growth and metabolic production. Metabolic flux is effectively redirected from growth to production by synthetic metabolic “valves” using a combination of controlled protein degradation and gene silencing, in a phosphate limited stationary phase. The approach offers the potential of standardized fermentation processes independent of the products to be made.  In addition, by limiting non-essential portions of the metabolic newtork we are able to improve performance robustness with respect to process conditions such as the oxygen environment and feeding strategy. As a result of increased robustness ,we have been able to successfully scale down our fermentations to 96 well plates, which give a high positive predictive value of 1L scale performance. Reliable scale up and icnreased proces robustness has enable rapid strain improvements across a variety of primary metabolites.