title: Enhanced production of epsilon-caprolactone by overexpression of NADPH-regenerating glucose 6-phosphate dehydrogenase in recombinant Escherichia coli harboring cyclohexanone monooxygenase gene.
abstract: Whole-cell conversion of cyclohexanone to epsilon-caprolactone was attempted by recombinant Escherichia coli BL21(DE3) expressing cyclohexanone monooxygenase (CHMO) of Acinetobacter calcoaceticus NCIMB 9871. High concentrations of cyclohexanone and epsilon-caprolactone reduced CHMO-mediated bioconversion of cyclohexanone to epsilon-caprolactone in the resting recombinant E. coli cells. Metabolically active cells were employed by adopting a fed-batch culture to improve the production of epsilon-caprolactone from cyclohexanone. A glucose-limited fed-batch Baeyer-Villiger oxidation where a cyclohexanone level was maintained less than 6 g/l resulted in a maximum epsilon-caprolactone concentration of 11.0 g/l. The maximum epsilon-caprolactone concentration was improved further to 15.3 g/l by coexpression of glucose-6-phosphate dehydrogenase, an NADPH-generating enzyme encoded by the zwf gene which corresponded to a 39% enhancement in epsilon-caprolactone concentration compared with the control experiment performed under the same conditions.
authors.affiliation: Department of Agricultural Biotechnology and Center for Agricultural Biomaterials, Seoul National University, Seoul 151-921, South Korea.
authors.forename: Won-Heong
authors.initials: WH
authors.lastname: Lee
authors.forename: Jin-Byung
authors.initials: JB
authors.lastname: Park
authors.forename: Kyungmoon
authors.initials: K
authors.lastname: Park
authors.forename: Myoung-Dong
authors.initials: MD
authors.lastname: Kim
authors.forename: Jin-Ho
authors.initials: JH
authors.lastname: Seo
mesh_terms: D019149:Bioreactors; D002208:Caproates / Q000737:chemistry / Q000378:metabolism*; D003512:Cyclohexanones / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D024861:Genetic Enhancement; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism*; D007783:Lactones / Q000737:chemistry / Q000378:metabolism*; D009249:NADP / Q000378:metabolism; D010105:Oxygenases / Q000378:metabolism*; D015202:Protein Engineering / Q000379:methods; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: D002208:Caproates; D003512:Cyclohexanones; D029968:Escherichia coli Proteins; D007783:Lactones; D011994:Recombinant Proteins; D009249:NADP; C121056:caprolactone; D005954:Glucosephosphate Dehydrogenase; D010105:Oxygenases; C019961:cyclohexanone oxygenase