2-Butanol and Butanone Production in Saccharomyces Cerevisiae through the B12 Dependent Dehydratase Pathway Using a Tev-Based Expression System

Butanone and 2-butanol are chemicals with rather decent potential to be used as either biofuels or biochemicals. In this study, an application of a TEV-protease based expression system is delineated with ultimate goal of attaining equimolar expression of the individual subunits of a B₁₂-dependent dehydratase used for constructing a 2-butanol pathway in Saccharomyces cerevisiae.  The dehydratase is taken from Lactobacillus reuterii and it is supposed to convert meso-2,3-butanediol to butanone. Subsequently, an NADH dependent secondary alcohol dehydrogenase, from Gordonia sp, was introduced to catalyze the conversion of butanone to 2-butanol.  Exploiting a Δgpd1,2 strain , we could provide the needed NADH for the alcohol dehydrogenase and therefore enforce the flux towards 2-butanol (by cultivating the cells under anaerobic conditions). A final concentration of 2 mg/l of butanone and 4±0.2 mg/l 2-butanol was found.