Production of monoterpene blends by unicellular photosynthetic microorganisms

A method of obtaining a blend of monoterpene hydrocarbons from cyanobacteria in which β-myrcene is the predominant monoterpene, the method comprising:

• culturing a cyanobacteria strain that has been genetically modified to express a heterologous Picea sitchensis β-phellandrene synthase as a fusion protein with a cyanobacteria CpcB polypeptide that has at least 95% identity to a wild type cyanobacteria CpcB polypeptide, wherein the heterologous Picea sitchensis β-phellandrene synthase has at least 95% identity to SEQ ID NO:
• 8 and is encoded by a polynucleotide comprising a Picea sitchensis β-phellandrene synthase nucleic acid sequence that is codon-optimized for expression in cyanobacteria, and is fused to the 3′ end of a leader nucleic acid sequence encoding the cyanobacteria CpcB polypeptide;
• isolating a blend of monoterpene hydrocarbons comprising β-myrcene, β-phellandrene, α-phellandrene, and β-pinene, produced in the cyanobacteria that has spontaneously diffused from the cyanobacteria intracellular space into the culture medium;
• analyzing the levels of monoterpenes present in the monoterpene blend;
• and
• determining that β-myrcene is the predominant monoterpene present in the blend of monoterpenes.