Fig. 4: Adopting dedicated selection strains supports efficient enzyme screening.
From: Automated in vivo enzyme engineering accelerates biocatalyst optimization
a Different types of auxotrophic selection strains can be used for in vivo enzyme evolution. The first group includes isolation and dissection strains; both strains are incapable of synthesizing essential biomass precursor(s) by blocking or isolating specific metabolic nodes. The second group is represented by strains unable to produce universal biomass intermediates (e.g., synthesis of NAD(P)H or amines). Red arrows indicate the auxotrophy generated. b Effect of reaction rates on selection strain’s growth profile. A selection strain produces two different enzyme variants capable of replenishing synthesis of a key biomass precursor through their enzymatic activity. The two enzyme variants display different reaction rates (µmol min−1). These different reaction rates will impact the in vivo selection, as the two selection strains can be distinguished by their different growth rates (h−1). Created with BioRender.com.
