Xl. Zhuang et al., Levoglucosan kinase involved in citric acid fermentation by Aspergillus niger CBX-209 using levoglucosan as sole carbon and energy source, BIO BIOENER, 21(1), 2001, pp. 53-60
Conditions were optimized for the production of citric acid by a mutant A.
niger CBX-209 using levoglucosan derived from pyrolysis of wastepaper as a
sole carbon and energy source in a simple medium. The optimum concentration
of levoglucosan and wheat bran in the medium was 8% and 3%, respectively,
at an optimum initial pH between 5.5 and 6.0 at 35 degreesC. During ferment
ation, direct formation of glucose 6-phosphate from levoglucosan in the pre
sence of ATP and Mg2+ as observed by HPLC in the reaction with both cell ex
tracts and partially purified enzyme, suggested that the enzyme acting on l
evoglucosan is a kinase. Time-course changes in the levels of this special
levoglucosan kinase in A. niger CBX-209 grown on levoglucosan and glucose r
evealed that levoglucosan kinase was an inductive enzyme. (C) 2001 Elsevier
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