title: Synthesis of cinnamyl alcohol from cinnamaldehyde with Bacillus stearothermophilus alcohol dehydrogenase as the isolated enzyme and in recombinant E. coli cells.
abstract: The synthesis of the aroma chemical cinnamyl alcohol (CMO) by means of enzymatic reduction of cinnamaldehyde (CMA) was investigated using NADH-dependent alcohol dehydrogenase from Bacillus stearothermophilus both as an isolated enzyme, and in recombinant Escherichia coli whole cells. The influence of parameters such as reaction time and cofactor, substrate, co-substrate 2-propanol and biocatalyst concentrations on the bioreduction reaction was investigated and an efficient and sustainable one-phase system developed. The reduction of CMA (0.5 g/L, 3.8 mmol/L) by the isolated enzyme occurred in 3 h at 50 °C with 97% conversion, and yielded high purity CMO (≥98%) with a yield of 88% and a productivity of 50 g/genzyme. The reduction of 12.5 g/L (94 mmol/L) CMA by whole cells in 6 h, at 37 °C and no requirement of external cofactor occurred with 97% conversion, 82% yield of 98% pure alcohol and a productivity of 34 mg/gwet cell weight. The results demonstrate the microbial system as a practical and efficient method for larger-scale synthesis of CMO.
authors.affiliation: Istituto di Biochimica delle Proteine, CNR, Via P. Castellino 111, 80131 Naples, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Pennacchio
authors.forename: Mosè
authors.initials: M
authors.lastname: Rossi
authors.forename: Carlo A
authors.initials: CA
authors.lastname: Raia
mesh_terms: D000171:Acrolein / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D000426:Alcohol Dehydrogenase / Q000737:chemistry* / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D001411:Geobacillus stearothermophilus / Q000201:enzymology* / Q000235:genetics; D020005:Propanols / Q000138:chemical synthesis* / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: D020005:Propanols; D011994:Recombinant Proteins; D000171:Acrolein; D000426:Alcohol Dehydrogenase; C012843:cinnamaldehyde; C020722:cinnamyl alcohol