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

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 alm ost completely converted to D-xylulose using Acetobacter aceti IFO 3281, Fi nally, D-lyxose was prepared from D-xylulose enzymatically using L-ribose i somerase from toluene-treated cells of Acinetobacter sp. strain DL-28, Tbe isomerization reaction progressed steadily and the concentration of D-xylul ose 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 m ixture is very difficult to achieve by column chromatography, but D-xylulos e could be selectively degraded easily using Saccharomyces cerevisiae IFO 0 841. The product was crystallized and was confirmed to be D-lyxose by HPLC, C-13-NMR spectra, IR spectra analysis, and optical rotation measurement.