A recombinant Saccharomyces cerevisiae strain transformed with xylose reductase (XR) and xylitol dehydrogenase (XDH) genes from Pichia stipitis (PsXR and PsXDH, respectively) has the ability to convert xylose to ethanol together with the unfavourable excretion of xylitol, which may be due to intercellular redox imbalance caused by the different coenzyme specificity between NADPH-preferring XR a...

XYL3, which encodes a D-xylulokinase (EC 2.7.1.17), was isolated from Pichia stipitis CBS 6054 genomic DNA by using primers designed against conserved motifs. Disruption of XYL3 eliminated D-xylulokinase activity, but D-ribulokinase activity was still present. Southern analysis of P. stipitis genomic DNA with XYL3 as a probe confirmed the disruption and did not reveal additional related genes. ...

Streptococcus mutans is strongly associated with caries in humans1 and its level in the mouth can be a good indicator of caries-risk. However, caries is a multifactorial disease and the presence of high levels of Streptococcus mutans at a particular site does not imply that such a site will inevitably develop a lesion. In addition, Streptococcus mutans is not found alone in association with car...

Clostridium thermocellum could potentially be used as a microbial biocatalyst to produce renewable fuels directly from lignocellulosic biomass due to its ability to rapidly solubilize plant cell walls. While the organism readily ferments sugars derived from cellulose, pentose sugars from xylan are not metabolized. Here, we show that non-fermentable pentoses inhibit growth and end-product format...

The nature of the metabolic defect in congenital pentosuria has not been determined, although considerable evidence is accumulating in regard to the metabolism of L-xylulose. This pentose, long known to be excreted in gm. quantities by pentosuric individuals, has been found in small amounts in the urine of “non-pentosuric” humans (2-4), guinea pigs (3), and rats (4). Touster, Mayberry, and McCo...

BACKGROUND Acute otitis media (AOM) is a common childhood illness and the leading indication for antibiotic prescriptions for US children. Xylitol, a naturally occurring sugar alcohol, can reduce AOM when given 5 times per day as a gum or syrup, but a more convenient dosing regimen is needed for widespread adoption. METHODS We designed a pragmatic practice-based randomized controlled trial to...