Application of a thermostable Baeyer-Villiger monooxygenase for the synthesis of branched polyester precursors

作者：Delgove Marie A F; Elford Matthew T; Bernaerts Katrien V; De Wildeman Stefaan M A^*

来源：Journal of Chemical Technology and Biotechnology, 2018, 93(8): 2131-2140.

DOI：10.1002/jctb.5623

• multi-enzymatic reactions
• Baeyer-Villiger monooxygenase (BVMO)
• branched lactone synthesis
• applied biocatalysis
• polymer application
• reaction engineering
• space-time-yield

BACKGROUNDIt is widely accepted that the poor thermostability of Baeyer-Villiger monooxygenases limits their use as biocatalysts for applied biocatalysis in industrial applications. The goal of this study was to investigate the biocatalytic oxidation of 3,3,5-trimethylcyclohexanone using a thermostable cyclohexanone monooxygenase from Thermocrispum municipale (TmCHMO) for the synthesis of branched E-caprolactone derivatives as building blocks for tuned polymeric backbones. In this multi-enzymatic reaction, the thermostable cyclohexanone monooxygenase was fused to a phosphite dehydrogenase (PTDH) in order to ensure co-factor regeneration.
RESULTSUsing reaction engineering, the reaction rate and product formation of the regio-isomeric branched lactones were improved and the use of co-solvents and the initial substrate load were investigated. Substrate inhibition and poor product solubility were overcome using continuous substrate feeding regimes, as well as a biphasic reaction system with toluene as water-immiscible organic solvent. A maximum volumetric productivity, or space-time-yield, of 1.20 g L-1 h(-1) was achieved with continuous feeding of substrate using methanol as co-solvent, while a maximum product concentration of 11.6 g L-1 was achieved with toluene acting as a second phase and substrate reservoir.
CONCLUSIONThese improvements in key process metrics therefore demonstrate progress towards the up-scaled Baeyer-Villiger monooxygenase-biocatalyzed synthesis of the target building blocks for polymer application.

• 出版日期2018-8