title: Bioproduction of 2-phenylethanol in a biphasic ionic liquid aqueous system.
abstract: 2-Phenylethanol (PEA) is a commercial flavor and fragrance compound, with a rose-like odor, used in the cosmetics and food industries. Saccharomyces cerevisiae strains produce PEA in a growth-associated manner but are prone to product inhibition, resulting in low production yields. The aim of this study was to use immiscible ionic liquids (ILs) in a biphasic system to enhance the PEA concentration by means of in situ product removal (ISPR). Nine ILs were tested for their influence on growing yeast cells, and five of them were found to be biocompatible. A correlation between the IL structure and the effect on yeast growth was investigated. [Tf(2)N] anions were found to be the most biocompatible in comparison to [PF(6)] and [BF(4)], and the pyridinium and ammonium cations were slightly preferable than the imidazolium cation. Furthermore, the longer the alkyl side chain on the imidazolium ring, the less it is biocompatible, with major significance above six carbons. The five biocompatible ILs were tested for PEA recovery capability by determining their distribution coefficients (K(D)), with the highest value of 17.6 obtained for BMIM[Tf(2)N]. Finally, ILs were tested for their efficiency as ISPR solvents under stress conditions of a high product concentration. A 3-5-fold increase in the total PEA concentration produced by the cells was obtained with MPPyr[Tf(2)N], OMA[Tf(2)N], and BMIM[Tf(2)N], demonstrating the potential of ILs for enhancing productivity in bioprocesses using growing cells.
authors.affiliation: Department of Biotechnology and Food Engineering, and Institute of Catalysis, Science and Technology, Technion-Israel Institute of Technology, Haifa 32000, Israel.
authors.forename: Mor
authors.initials: M
authors.lastname: Sendovski
authors.forename: Netta
authors.initials: N
authors.lastname: Nir
authors.forename: Ayelet
authors.initials: A
authors.lastname: Fishman
mesh_terms: D000327:Adsorption; D000838:Anions / Q000737:chemistry; D001672:Biocompatible Materials; D002412:Cations / Q000737:chemistry; D003470:Culture Media; D052578:Ionic Liquids / Q000737:chemistry; D008958:Models, Molecular; D010626:Phenylethyl Alcohol / Q000138:chemical synthesis* / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000378:metabolism; D012995:Solubility; D014867:Water
chemical_list: D000838:Anions; D001672:Biocompatible Materials; D002412:Cations; D003470:Culture Media; D052578:Ionic Liquids; D014867:Water; D010626:Phenylethyl Alcohol