Production of d-lyxose from d-glucose by microbial and enzymatic reactions

Abstract

d-Arabitol was first prepared from d-glucose using Candida famata R28. The reaction gave 5.0% d-arabitol from 10.0% d-glucose. d-Arabitol was then almost completely converted to d-xylulose using Acetobacter aceti IFO 3281. Finally, d-lyxose was prepared from d-xylulose enzymatically using l-ribose isomerase from toluene-treated cells of Acinetobacter sp. strain DL-28. The isomerization reaction progressed steadily and the concentration of d-xylulose increased from 1.0 to 10.0%. About 70% of d-xylulose was converted to d-lyxose in all cases. Separation of residual d-xylulose from the reaction mixture is very difficult to achieve by column chromatography, but d-xylulose could be selectively degraded easily using Saccharomyces cerevisiae IFO 0841. The product was crystallized and was confirmed to be d-lyxose by HPLC, 13C-NMR spectra, IR spectra analysis, and optical rotation measurement.