Chemo-enzymatic cascades to produce cycloalkenes from bio-based resources

Shuke Wu,Markus Jeschek,Yi Zhou,Daniel Gerngross,Thomas R Ward

doi:10.1038/s41467-019-13071-y

Abstract

Engineered enzyme cascades offer powerful tools to convert renewable resources into value-added products. Man-made catalysts give access to new-to-nature reactivities that may complement the enzyme’s repertoire. Their mutual incompatibility, however, challenges their integration into concurrent chemo-enzymatic cascades. Herein we show that compartmentalization of complex enzyme cascades within E. coli whole cells enables the simultaneous use of a metathesis catalyst, thus allowing the sustainable one-pot production of cycloalkenes from oleic acid. Cycloheptene is produced from oleic acid via a concurrent enzymatic oxidative decarboxylation and ring-closing metathesis. Cyclohexene and cyclopentene are produced from oleic acid via either a six- or eight-step enzyme cascade involving hydration, oxidation, hydrolysis and decarboxylation, followed by ring-closing metathesis. Integration of an upstream hydrolase enables the usage of olive oil as the substrate for the production of cycloalkenes. This work highlights the potential of integrating organometallic catalysis with whole-cell enzyme cascades of high complexity to enable sustainable chemistry.

Highlights

Engineered enzyme cascades offer powerful tools to convert renewable resources into valueadded products
The diacids 4a and 4b are produced via a six- and four enzyme-cascade, respectively (Fig. 2b). This is achieved via hydration of oleic acid (6) by OhyA2, followed by oxidation with MlADH to the corresponding keto-acid
As olive oil is readily hydrolyzed by TLL to afford oleic acid 6, one may be able to produce cycloalkenes 1a-1c, typically derived from petroleum-based feedstocks, from renewable resources via a concurrent chemo-enzymatic cascade

Summary

Results

The diacids 4a and 4b are produced via a six- and four enzyme-cascade, respectively (Fig. 2b) This is achieved via hydration of oleic acid (6) by OhyA2, followed by oxidation with MlADH to the corresponding keto-acid. Subjecting the keto-acid to a Baeyer–Villiger monooxygenase, using either PpBVMO or PfBVMO, followed by hydrolysis by TLL affords either sebacic acid (4b) –with PfBVMO– or a hydroxy-carboxylic acid –with PpBVMO–. The latter may be oxidized by ChnD and ChnE to afford azelaic acid (4a)[55] (Fig. 2b, Supplementary Fig. 1 for details). As olive oil is readily hydrolyzed by TLL to afford oleic acid 6, one may be able to produce cycloalkenes 1a-1c, typically derived from petroleum-based feedstocks, from renewable resources via a concurrent chemo-enzymatic cascade

TLL H2O

Discussion

Methods

Code availability