ARS | Publication request: NOVEL ROUTES TO XYLITOL SYNTHESIS USING ESCHERICHIA COLI

Submitted to: Great Lakes Regional American Chemical Society Symposium
Publication Acceptance Date: October 20, 2004
Publication Date: October 20, 2004
Citation: Taylor, P., Wymer, N., Racine, M., Sakakibara, Y., Saha, B.C. 2004. Novel Routes To Xylitol Synthesis Using Escherichia Coli [abstract]. Great Lakes Regional American Chemical Society Symposium. Paper No. 378.

Technical Abstract: Xylitol is a five-carbon polyalcohol that has gained acceptance as a natural food sweetener that can replace sucrose on a weight for weight basis in many applications. It has a similar sweetness and bulk as sucrose with one-third fewer calories and no unpleasant aftertaste. It also helps prevent dental caries and is metabolized independently of insulin, leading to its applications in oral health and diabetic products. Currently, xylitol is synthesized by catalytic hydrogenation of D-xylose rich hydrolysates of either birch tree pulp or corn cobs. Birch tree hydrolysates are naturally low in L-arabinose and other sugars that if hydrogenated would cause major problems for xylitol isolation but have very limited availability. Corn cob hydrolysates on the other hand require a great deal of expensive refining to remove other sugars. This effectively leaves little room for reducing the overall cost of these processes. Our laboratory is researching xylitol synthesis routes that can utilize less expensive and readily available substrates that do not depend on high purity D-xylose. For this we have explored a number of different pathways and developed powerful screens for enhancing individual enzymes and pathways. Here we will present some of our attempts to provide solutions to this problem using Escherichia coli as a fermentation/bioconversion host.