Sh. Bhuiyan et al., A new method for the production of L-lyxose from ribitol using microbial and enzymatic reactions, J FERM BIOE, 86(5), 1998, pp. 513-516
L-Lyxose was prepared from ribitol by a. new method comprising a potent mic
robial oxidation reaction to convert ribitol to L-ribulose, epimerization o
f the L-ribulose to L-xylulose, and isomerization of the L-xylulose to prod
uce L-lyxose. The complete transformation of ribitol to L-ribulose was achi
eved using washed cells of Acetobacter aceti IFO 3281 at high substrate con
centrations ranging from 5-20%. The L-ribulose produced was then used as th
e substrate for the production of L-lyxose using immobilized L-rhamnose iso
merase (L-RI) of Pseudomonas sp. strain LL172 and immobilized D-tagatose 3-
epimerase (D-TE) of recombinant Escherichia coli JM 105. At equilibrium, th
e yield of L-lyxose from L-ribulose was determined to be about 60%, and the
product could be isolated easily from the reaction mixture after degradati
on of ketoses using Pseudomonas sp. 172a. Following various product purific
ation steps, about 5.0 g L-lyxose crystals were recovered from 10.0 g ribit
ol in a flask reaction. The crystallized product was finally identified by
HPLC, IR spectrum, NMR, and optical rotation measurements.