원문정보
초록
영어
Previously, we studied the production of 3-hydroxypropionic acid (3-HP) from glycerol using the
recombinant Escherichia coli strains expressing glycerol dehydratase (dhaB1, dhaB2, and dhaB3)
and 3-hydroxypropionaldehyde dehydrogenase (aldH). The present study aims to improve the
performance of the biocatalysts. In order to do so, the recombinant strains were further
developed to contain the genes gdrAB, which encode the glycerol dehydratase reactivase, and the
gene KGSADH-I (α–ketoglutaric semialdehyde dehydrogenase) in place of aldH, under two
different vectors. The enzyme expression and their activities with respect to different
concentrations of IPTG induction were studied. The specific activities of DhaB at co-expressed
conditions decreased drastically than expressing it individually in the recombinant strains. But,
the specific activities of AldH and KGSADH-I were shown slight difference at the co-expression
conditions. The crude cell activity of KGSADH-I exhibited 2-fold higher specific activity than
that of AldH. When the recombinants harboring the gene aldH or KGSADH-I with dhaB and
gdrAB grown on a glycerol medium, the maximum titer of 3-HP was 14.9 mmol l-1 with AldH
construct and 31 mmol l–1 with KGSADH-I construct. In this report, we demonstrate that the
enhanced production of 3-HP under shake flask conditions was closely related to the enzyme
characteristics of the recombinant biocatalysts.