Novel approach in the biosynthesis of functional carotenoids in Escherichia coli.

Many carotenoid pigments are present in a small quantity in nature or low yielding from their natural sources, despite these vivid colorations. Thus, the synthesis of useful carotenoids with metabolic pathway-engineered microorganisms should offer an alternative and promising approach for their efficient production. Here, we describe a novel method for an efficient production of such carotenoids, using E. coli cells that carry heterologous mevalonate pathway-based genes. This method also enables relevant researchers to efficiently identify the function of an isolated carotenogenic gene candidate. For example, the recombinant E. coli cells, which harbor a lycopene-producing plasmid, can synthesize 12.5 mg/g dry cell weight of lycopene with the addition of lithium acetoacetate to the medium. This level corresponded to an 11.8-fold increase of that of E. coli cells carrying only the lycopene-producing plasmid.