Figure 2. Biosynthesis of fatty alcohols and alkanes. (A) We optimized a model that generates alcohols with a carboxylic acid reductase (CAR) by fitting the product profile of a strain of E. coli overexpressing four enzymes: a thioesterase (TE), a CAR, an aldehyde reductase (AHR), and a 4’-phosphopantetheinyl transferase (Sfp; (Kalim Akhtara et al., 2013)). (B) We optimized our model for alkane biosynthesis by fitting the product profile and titer of a strain overexpressing both an acyl-ACP reductase (AAR) and an aldehyde deformylating oxygenase (ADO; (Song et al., 2016)). Table S9 describes the compositions of the modeled pathways.