Effect of the support matrix on biotransformation of benzaldehyde to benzyl alcohol by yeast cells in aqueous and aqueous-organic two phase systems

Biotransformation of benzaldehyde to benzyl alcohol bySaccharomyces cerevisiae immobilized in different support matrices was investigated. Polymers with intrinsic hydrophobic and/or hydrophilic nature as well as mixed hydrophobic and hydrophilic supports were examined both in aqueous and bisphasic aqueous-organic systems. The hydrophobic support material ENTP-2000 or mixed silicone:alginate (50-25∶50-75) proved to be most suitable not only for nonconventional media but also for conventional aqueous media for production of benzyl alcohol. With ENTP-2000, catalytic activity and maximum yield were 159 μmol h−1 g−1 dry weight catalyst and 0.89 mM, respectively, in hexane containing 2% moisture. Corresponding values in aqueous media were 246 μmol h−1 g−1 dry weight catalyst and 1.53 mM. With 50∶50 silicone:alginate, catalytic activity and maximum yield were 177 μmol h−1 g−1 dry weight catalyst and 1.18 mM, respectively, in hexane containing 2% moisture. Corresponding values in aqueous media were 192 μmol h−1 g−1 dry weight catalyst and 0.8 mM.