title: Hyperexpression of Escherichia coli Xylose Isomerase.
abstract: The xylose isomerase (xylA) structural gene was cloned under the control of the tac promoter and expressed in a xyl(+) E. coli strain. Xylose isomerase accounted for approximately 28% of the total cell protein when this tac-xylA fusion was induced with isopropylthio beta-D-galactopyranoside. Hyperexpression of the xylA gene inhibited xylose utilization. E. coli carrying this tac-xylA fusion was encapsulated in calcium-alginate beads and used to isomerase xylose in a column reactor. Conversion of xylose to xylulose was 3-4% with a residence time in the column of 2 minutes and a maximum of 12% upon recycling.
authors.affiliation: Department of Food Science, Cornell Universty, Ithaca, N. Y. 14853.
authors.forename: C A
authors.initials: CA
authors.lastname: Batt
authors.forename: E
authors.initials: E
authors.lastname: O'Neill
authors.forename: S R
authors.initials: SR
authors.lastname: Novak
authors.forename: J
authors.initials: J
authors.lastname: Ko
authors.forename: A
authors.initials: A
authors.lastname: Sinskey