Levoglucosan (LG), 1,6-anhydro-beta -D-glucopyranose. was produced by pyrol
ysis of cellulose. A response surface method was used to optimize the react
ion parameters: X-1, temperature; X-2, time required for heating cellulose
from room temperature to the designed pyrolysis temperature; and X-3. vacuu
m, and a Box-Behnken design was employed for this purpose. The optimal temp
erature and time were found to be 388 degreesC and 26.2 min by fixing the v
acuum at 1 mm HE. The levoglucosan prepared was fermented to citric acid by
Aspergillus niger CBX-309, which was a mutant derived by gamma -ray mutage
nesis of the parent strain CBX-2. The mutant could produce increasing citri
c acid with increasing LG purity and had a citric acid yield of 87.5% when
using purified levoglucosan as the sole carbon source in a 5 day fermentati
on period. (C) 2001 Elsevier Science Ltd. All rights reserved.