Fig. 1: Overall workflow for the microbial production of 15 short-chain primary amines (SCPAs).

The workflow implemented in this study largely consists of the following steps: (a) target chemical selection; (b) prediction of precursors and relevant third-level EC numbers for the generation of these precursors; (c) selection of precursors having a suitable molecular type; (d) selection of precursors having a consistent relative position of functional groups; (e) in vitro production using purified enzyme VlmD; (f) in vivo production via feeding of direct precursors; and (g) de novo production from glucose. Amine, carboxylic, hydroxy and CoA groups are presented with yellow, green, blue, and pink circles, respectively. In (c) and (d), these two steps are collectively referred to as the precursor selection step where precursors that meet the selection criteria are presented with a check mark.