Patent ID: 8236512

Claim:
A method of testing a terpene synthase variant for improved in vivo performance, comprising the steps of: (a) dividing a population of host cells into a control population and a test population; (b) co-expressing in the control population a control terpene synthase (S 1 ) and a comparison terpene synthase (S 2 ), wherein the control terpene synthase can convert a polyprenyl diphosphate to a first terpene (T 1 ) and the comparison terpene synthase can convert the same polyprenyl diphosphate to a different second terpene (T 2 ) and wherein said control terpene synthase and comparison terpene synthase compete for the same pool of polyprenyl diphosphate; (c) co-expressing in the test population a test terpene synthase (S 1 ′) and the comparison terpene synthase (S 2 ), wherein the test terpene synthase is a variant of the control terpene synthase that can convert the same polyprenyl diphosphate to the same first terpene (T 1 ) as the control terpene synthase, and wherein the comparison terpene synthase can convert the same polyprenyl diphosphate to a different second terpene (T 2 ) and is expressed at similar levels in the test population and in the control population; and (d) measuring a ratio of the first terpene over the second terpene (T 1 /T 2 ) in both the test population and in the control population, wherein the test population is identified as comprising a terpene synthase variant having improved in vivo performance compared to the control terpene synthase by having an increase in the ratio of the first terpene over the second terpene in the test population compared to that in the control population.