Preparation of levoglucosan by pyrolysis of cellulose and its citric acid fermentation.
Levoglucosan (LG), 1,6-anhydro-beta-D-glucopyranose, was produced by pyrolysis of cellulose. A response surface method was used to optimize the reaction parameters: X1, temperature; X2, time required for heating cellulose from room temperature to the designed pyrolysis temperature; and X3, vacuum, and a Box-Behnken design was employed for this purpose. The optimal temperature and time were found to be 388 degrees C and 26.2 min by fixing the vacuum at 1 mm Hg. The levoglucosan prepared was fermented to citric acid by Aspergillus niger CBX-209, which was a mutant derived by gamma-ray mutagenesis of the parent strain CBX-2. The mutant could produce increasing citric 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 fermentation period.
Zhuang
X L
XL
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing.
Zhang
H X
HX
Yang
J Z
JZ
Qi
H Y
HY
D001234:Aspergillus niger / Q000378:metabolism; D002482:Cellulose / Q000737:chemistry*; D019343:Citric Acid / Q000378:metabolism*; D005285:Fermentation; D005947:Glucose / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000378:metabolism; D006358:Hot Temperature
D019343:Citric Acid; C014989:1,6-anhydro-beta-glucopyranose; D002482:Cellulose; D005947:Glucose