Direct 1,3-butadiene biosynthesis in Escherichia coli via a tailored ferulic acid decarboxylase mutant

The C4 unsaturated compound 1,3-butadiene is an important monomer in synthetic rubber and engineering plastic production. However, microorganisms cannot directly produce 1,3-butadiene using glucose as a renewable carbon source via biological processes. This study constructed a novel artificial metabolic pathway for 1,3-butadiene production from glucose in Escherichia coli by combining the cis,cis-muconic acid (ccMA)-producing pathway and tailored ferulic acid decarboxylase mutants. The rational enzyme design of the substrate-binding site by computational simulation improved 1,3-butadiene-producing ccMA decarboxylation with a small mutant library. We found that changing dissolved oxygen and controlling pH were important factors for 1,3-butadiene production. Using dissolved oxygen–stat fed-batch fermentation in a 1-L jar fermenter, we could produce 2.1 g L− 1 of 1,3-butadiene. These results indicated that using a rational enzyme design, we can produce unnatural/nonbiological compounds (those that are made from petroleum and cannot be produced by microorganisms) using glucose as a renewable carbon source.