We generated an expression construct consisting of the xylose reductase (XR) gene (xr) from Phanerochaete chrysosporium. Transformant X7 exhibited increased xylitol production and markedly higher XR activities than the wild-type strain. RT-PCR analysis demonstrated that the increased XR activity was associated with constant expression of the recombinant xr gene.

A xylose reductase (XR) gene was identified from the Neurospora crassa whole-genome sequence, expressed heterologously in Escherichia coli, and purified as a His6-tagged fusion in high yield. This enzyme is one of the most active XRs thus far characterized and may be used for the in vitro production of xylitol.

BACKGROUND Human airway surface liquid (ASL) has abundant antimicrobial peptides whose potency increases as the salt concentration decreases. Xylitol is a 5-carbon sugar that has the ability to lower ASL salt concentration, potentially enhancing innate immunity. Xylitol was detected for 8 hours in the ASL after application in airway epithelium in vitro. We tested the airway retention time of ae...

The effect of peroral administration of xylitol (5% or 20% in food) on adrenal function was investigated in thirty-five Long-Evans male rats. The control rats were fed either a non-substituted stock diet or a 20% glucose diet. Glucose elevated and 20% xylitol reduced the growth of the rats (P less than 0.001), but 5% xylitol had no effect on the body weight. The concentrations of serum glucose ...

OBJECTIVES This study was designed to evaluate the synergistic antibacterial effect of xylitol and ursolic acid (UA) against oral biofilms in vitro. MATERIALS AND METHODS S. mutans UA 159 (wild type), S. mutans KCOM 1207, KCOM 1128 and S. sobrinus ATCC 33478 were used. The susceptibility of S. mutans to UA and xylitol was evaluated using a broth microdilution method. Based on the results, com...

Objectives: The aim of this study is to investigate the effectiveness of dentifrice containing xylitol on the growth of salivary mutans streptococci. The amount of salivary mutans streptococci which was taken before and after tooth brushing from the groups using dentifrice containing xylitol and non-xylitol dentifrice are compared. The study was carried out to investigate the effect of dentifri...

Dental caries are one of the most common infectious diseases occurred in Thai children. The chewing of xylitol, sorbitol, and even sugar gum has been suggested to reduce caries rates. The aim of the present investigation was to evaluate the effect of xylitol chewing gum on mutans streptococci (MS) in saliva and dental plaque. Ninety-one children, aged 10-12 years, with more than 1 x 10(5) MS pe...

Visible-wavelength Raman spectroscopy was used to investigate the uptake and metabolism of the five-carbon sugar alcohol xylitol by Gram-positive viridans group streptococcus and the two extensively used strains of Gram-negative Escherichia coli, E. coli C and E. coli K-12. E. coli C, but not E. coli K-12, contains a complete xylitol operon, and the viridans group streptococcus contains an inco...

The exposure of either epithelial cells or pneumococci or both to 5% xylitol reduced the adherence of pneumococci. Exposure of epithelial cells or bacteria alone to xylitol did not reduce the adherence of Haemophilus influenzae, although the exposure of both cells and bacteria to xylitol reduced the adherence significantly. The adherence of Moraxella catarrhalis remained low irrespective of the...

The conversion of d-xylose to ethanol by the yeast Pachysolen tannophilus is relatively inefficient in batch culture. The inefficiency has been attributed in part to concurrent utilization of ethanol in the presence of appreciable concentrations of d-xylose and to the formation of xylitol and other by-products. To increase the concentration of ethanol accumulated in batch cultures, UV-induced m...