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Role of xylose transporters in xylitol production from engineered Escherichia coli

Paper ID Volume ID Publish Year Pages File Format Full-Text
24774 43536 2008 7 PDF Available
Title
Role of xylose transporters in xylitol production from engineered Escherichia coli
Abstract

Escherichia coli W3110 was previously engineered to co-utilize glucose and xylose by replacing the wild-type crp gene with a crp* mutant encoding a cAMP-independent CRP variant (Cirino et al., 2006 [Cirino, P.C., Chin, J.W., Ingram, L.O., 2006. Engineering Escherichia coli for xylitol production from glucose–xylose mixtures. Biotechnol. Bioeng. 95, 1167–1176.]). Subsequent deletion of the xylB gene (encoding xylulokinase) and expression of xylose reductase from Candida boidinii (CbXR) resulted in a strain which produces xylitol from glucose–xylose mixtures. In this study we examine the contributions of the native E. coli xylose transporters (the d-xylose/proton symporter XylE and the d-xylose ABC transporter XylFGH) and CRP* to xylitol production in the presence of glucose and xylose. The final batch xylitol titer with strain PC09 (ΔxylB and crp*) is reduced by 40% upon deletion of xylG and by 60% upon deletion of both xyl transporters. Xylitol production by the wild-type strain (W3110) expressing CbXR is not reduced when xylE and xylG are deleted, demonstrating tight regulation of the xylose transporters by CRP and revealing significant secondary xylose transport. Finally, plasmid expression of XylE or XylFGH with CbXR in PC07 (ΔxylB and wild-type crp) growing on glucose results in xylitol titers similar to that achieved with PC09 and provides an alternative strategy to the use of CRP*.

Keywords
Xylose; Transport; Xylitol; CRP; Biocatalysis; Escherichia coli; Overflow metabolism; Sugar mixtures
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Role of xylose transporters in xylitol production from engineered Escherichia coli
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Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Biotechnology - Volume 134, Issues 3–4, 30 April 2008, Pages 246–252
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us