ARS | Publication request: Microbial production of xylitol from xylose and L-arabinose: conversion of L-arabitol to xylitol using bacterial oxidoreductases

Submitted to: UJNR Food & Agricultural Panel Proceedings
Publication Type: Proceedings/Symposium
Publication Acceptance Date: August 24, 2008
Publication Date: August 24, 2008
Citation: Sakakibara, Y., Saha, B.C. 2008. Microbial production of xylitol from xylose and L-arabinose: conversion of L-arabitol to xylitol using bacterial oxidoreductases. Proceedings of the United States-Japan Cooperative Program in Natural Resources Food and Agriculture Panel 37th Annual Meeting, August 24-28, 2008, Chicago, Illinois. p. 48-49.

Technical Abstract: Microbial production of xylitol, using hemicellulosic biomass such as agricultural residues, is becoming more attractive for reducing its manufacturing cost. L-arabitol is a particular problem to xylitol production from hemicellulosic hydrolyzates that contain both xylose and L-arabinose because it can be generated from L-arabinose as a byproduct and it is very difficult to separate from xylitol in a cost effective way. We have developed a recombinant Escherichia coli strain that converts L-arabitol to xylitol through L-xylulose by expressing ribitol dehydrogenase of Klebsiella pneumoniae and L-xylulose reductase of Ambrosiozyma monospora. The recombinant E. coli produced 4.6 g/L of xylitol from 11.9 g/L of L-arabitol in 49 h with the yield of 0.39 g/g L-arabitol. In addition, a new oxidoreductase highly specific for L-arabitol was isolated from Pantoea ananatis. It oxidized L-arabitol mainly to L-ribulose and partially to L-xylulose. We are presently attempting to produce xylitol from L-arabitol using this enzyme.