Rm. Mizanur et al., Production of L-erythrose via L-erythrulose from erythritol using microbial and enzymatic reactions, J BIOSCI BI, 92(3), 2001, pp. 237-241
A rare aldotetrose, L-erythrose, was produced from erythritol via a two-ste
p reaction. In the first step, complete oxidation of erythritol to L-erythr
ulose was achieved by using Gluconobacter frateurii IFO 3254. Washed cell s
uspension of the strain grown on tryptic soy broth (TSB) supplemented with
1% D-sorbitol was used to carry out the transformation reaction at 30 degre
esC with shaking at 170 rpm. At 10% substrate concentration, 98% erythritol
was converted to L-erythrulose within 48 h. The produced L-erythrulose was
then used as a substrate for the production of L-erythrose. The isomerizat
ion of L-erythrulose to L-erythrose was carried out using constitutively pr
oduced L-ribose isomerase (L-RI) from the mutant strain Acinetobacter sp. D
L-28 grown on D-lyxose mineral salt medium. At equilibrium, the yield of L-
erythrose from L-erythrulose was 18% and finally 1.7 g L-erythrose was obta
ined from 10 g erythritol. After a number of simple purification steps, the
product was isolated from the reaction mixture by ion-exchange column chro
matography (Dowex 50W-X2, Ca2+). The structure of the product was determine
d after NaBH4 reduction from Infrared (IR) and C-13 nuclear magnetic resona
nce (NMR) spectra.