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Hyperexpression of Escherichia coli Xylose Isomerase
Author(s) -
Batt Carl A.,
O'Neill Elizabeth,
Novak Steven R.,
Ko Judy,
Sinskey Anthony
Publication year - 1986
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1002/btpr.5420020308
Subject(s) - xylose isomerase , xylose , isomerase , biochemistry , escherichia coli , chemistry , enzyme , biology , gene , fermentation
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 β‐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.