Determination of effective diffusion coefficient of acetophenone in kappa-carrageenan and asymmetric bioreduction in packed bed reactor

Aydogan O., BAYRAKTAR E., Mehmetoglu U.

JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC, vol.72, no.1-2, pp.46-52, 2011 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 72 Issue: 1-2
  • Publication Date: 2011
  • Doi Number: 10.1016/j.molcatb.2011.04.023
  • Journal Name: JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.46-52
  • Keywords: Effective diffusion coefficient, Acetophenone, Asymmetric bioreduction, kappa-Carrageenan, Packed bed reactor, Lactobacillus kefir, SUBSTITUTED ACETOPHENONES, ENANTIOSELECTIVE REDUCTION, BAKERS-YEAST, CELLS, BIOTRANSFORMATIONS, BIOCATALYSTS, KINETICS, ALCOHOL, SYSTEM, GEL
  • Ankara University Affiliated: Yes

Abstract

The effective diffusion coefficient and bioreduction of acetophenone in 1% kappa-carrageenan gel containing Lactobacillus kefir NRRL B-1839 were investigated experimentally. Both free and immobilized cells in 0.3 cm and 0.4 cm diameter particles were used and the results were analyzed according to Michaelis-Menten kinetics and the values of the constants were determined as: r(max) = 0.18 mmol L-1 min(-1), K-M0 = 0.37 mmol L-1, K-M1, = 1.68 mmol L-1. and K-M2 = 2.66 mmol L-1. Effective diffusion coefficient for acetophenone in kappa-carrageenan was determined as D-e = 3.0 x 10(-7) cm(2)/s. Using immobilized Lactobacillus kefir in an up-flow packed bed reactor, continuous production of (R)-1-phenylethanol through asymmetric bioreduction of acetophenone was carried out using glucose as an energy source. The effects of the residence time and concentrations of substrate and glucose on conversion were investigated at pH 8 and 35 degrees C. Enantiomerically pure (R)-1-phenylethanol (ee > 99%) was produced with a conversion of 79% and productivity of 2.50 mmol L-1 h(-1) at 15 mmol L-1 substrate and 0.02 g/mL glucose concentration. (C) 2011 Elsevier B.V. All rights reserved.