Photosynthesis in the cyanobacterium Synechocystis sp. PCC 6803 is used to generate enough NADPH to drive the enzymatic reduction of cyclic ketones to their corresponding lactones. This reaction is catalyzed by the cyclohexanone monooxygenase (CHMO) from Acinetobacter calcoaceticus NCIMB 9871. However, the reduction of saturated cyclic ketones by native alcoholdehydrogenases (ADHs) in Synechocysits sp. lower conversion rates. Minimized ketone concentrations and accelerated reactions toward the lactone would decrease the influence of ketoreduction. Here, the CHMO is combined with the ene-reductase YqjM of Bacillus subtilis in an cascade reaction. For now, both enzymes are expressed in different cells which were mixed for in vivo biotransformations. This offers the possibility to compensate expression levels and enzyme activities by precisely dosing both cells. However, coexpression of both enzymes would simplify the work progress and would prevent transport problems between the cells.
|Publication status||Published - 9 Apr 2018|