title: (R)-PAC biosynthesis in [BMIM][PF₆]/aqueous biphasic system using Saccharomyces cerevisiae BY4741 cells.
abstract: (R)-phenylacetylcarbinol or (R)-PAC is a pharmaceutical precursor of (1R, 2S) ephedrine and (1S, 2S) pseudoephedrine. Biotransformation of benzaldehyde and glucose by pyruvate decarboxylase produces (R)-PAC. This biotransformation suffers from toxicity of the substrate, product [(R)-PAC] and by-product (benzyl alcohol). In the present study, ionic liquid/aqueous biphasic system was employed to enhance (R)-PAC production. Fermented broth was the reaction medium in which Saccharomyces cerevisiae BY4741 was the source of pyruvate decarboxylase. Hydrophobic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) was the non-aqueous phase in which toxic compounds reside. Biocompatibility of [BMIM][PF6] and adequate distribution coefficients of benzaldehyde, (R)-PAC and benzyl alcohol were determined. A Box-Behnken design and response surface methodology were used for the optimization of biotransformation variables in order to maximize (R)-PAC yield and productivity. The results showed higher (R)-PAC yield and productivity of ∼1.5-fold each in the biphasic biotransformation of phase volume ratio 0.05 as compared to the monophasic (conventional) biotransformation. Moreover, the level of major by-product benzyl alcohol was also 3.5-fold lower in biphasic biotransformation. [BMIM][PF6]/aqueous biphasic system is a new approach which could intensify the (R)-PAC production.
authors.affiliation: Department of Bioscience and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India, smitakandar@rediffmail.com.
authors.forename: Smita
authors.initials: S
authors.lastname: Kandar
authors.forename: A K
authors.initials: AK
authors.lastname: Suresh
authors.forename: Santosh B
authors.initials: SB
authors.lastname: Noronha
mesh_terms: D000096:Acetone / Q000031:analogs & derivatives* / Q000378:metabolism; D001547:Benzaldehydes / Q000378:metabolism*; D019149:Bioreactors; D001711:Biotransformation; D005163:Factor Analysis, Statistical; D005285:Fermentation; D005947:Glucose / Q000378:metabolism*; D007093:Imidazoles / Q000737:chemistry / Q000494:pharmacology; D007218:Industrial Microbiology; D052578:Ionic Liquids / Q000737:chemistry / Q000494:pharmacology; D011767:Pyruvate Decarboxylase / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*
chemical_list: C412621:1-butyl-3-methylimidazolium hexafluorophosphate; D001547:Benzaldehydes; D007093:Imidazoles; D052578:Ionic Liquids; D029701:Saccharomyces cerevisiae Proteins; D000096:Acetone; C035293:1-hydroxy-1-phenyl-2-propanone; D011767:Pyruvate Decarboxylase; D005947:Glucose; C032175:benzaldehyde