Photosynthetic 1,8-cineole production using cyanobacteria.

Terpenoid is an important group of compounds not only as biocomponents but also as useful secondary metabolites. A volatile terpenoid 1,8-cineole, which is used as a food additive, flavoring agent, cosmetic, etc., is also attracting attention from a medical perspective due to its antiinflammation and antioxidation. The 1,8-cineole fermentation using a recombinant Escherichia coli strain has been reported, although a carbon source supplement is necessary for a high-yield 1,8-cineole production. We constructed the 1,8-cineole-producing cyanobacteria toward a carbon-free and sustainable 1,8-cineole production. cnsA, the 1,8-cineole synthase gene in Streptomyces clavuligerus ATCC 27064, was introduced and overexpressed in the cyanobacterium Synechococcus elongatus PCC 7942. We succeeded in producing an average of 105.6 µg g-1 wet cell weight of 1,8-cineole in S. elongatus 7942 without supplementing any carbon source. Using the cyanobacteria expression system is an efficient approach to producing 1,8-cineole by photosynthesis.