Xylitol production was compared in fed batch fermentation by Saccharomyces cerevisiae strains overexpressing xylose reductase (XR) genes from Candida tropicalis, Pichia stipitis, Neurospora crassa, and an endogenous gene GRE3. The gene encoding a xylose specific transporter (SUT1) from P. stipitis was cloned to improve xylose transport and fed batch fermentation was used with glucose as a cosub...

Microorganisms capable of producing xy]itol from Darabitol were screened for. Of the 420 strains tested, three bacteria, belonging to the genera Acetobacter and Gluconobacter, produced xylitol from D-arabitol when intact cells were used as the enzyme source. Among them, Gluconobacter oxydans ATCC 621 produced 29.2 g!1 xylitol from 52.4 g!1 D-arabitol after incubation for 27 h. The production of...

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...

Xylitol is a natural sweetener used commercially as a substitute for sucrose, mainly by its low-calorie and anticariogenic properties. Moreover, its metabolism is independent of insulin, which can be used by people with diabetes and obesity problems. Currently, xylitol is produced by catalytic hydrogenation of D-xylose, a costly process because it requires highly purified xylose syrup. As an al...

Under oxygen transfer rates (OTR), from 10 to 30 mmol. l –1 h , Candida boidinii NRRL Y-17213 exhibited both NADH and NADPH linked D-xylose reductase activities with the former being higher. Xylitol dehydrogenase was mainly NAD dependent. Maximum xylitol production was attained at OTR of 14 mmol. l h . Ethanol, glycerol and ribitol were also produced. A correlation between xylitol accumulation,...

Xylitol is a naturally occurring five-carbon containing sugar alcohol. It has attracted a lot of attention in the pharmaceutical, cosmetics, food, and dental industries due to its high sweetening ability, anticariogenic properties and possibilities for use in insulin-dependent diabetics. Thus, the establishment of a simple and rapid method for the determination of xylitol with high selectivity ...

BACKGROUND Habitual consumption of xylitol reduces mutans streptococci (MS) levels but the effect on Lactobacillus spp. is less clear. Reduction is dependent on daily dose and frequency of consumption. For xylitol to be successfully used in prevention programs to reduce MS and prevent caries, effective xylitol delivery methods must be identified. This study examines the response of MS, specific...

due to the widespread applications of xylitol dehydrogenase, an enzyme used for the production of xylitol, the present study was designed for the cloning of xylitol dehydrogenase gene from glcunobacter oxydans dsm 2003. after extraction of genomic dna from this bacterium, xylitol dehydrogenase gene was replicated using polymerase chain reaction (pcr). the amplified product was entered into ptz5...

D ental caries is a significant public health problem for a large proportion, of the Saudi population, especially the child segment. Preventive strategies tend to focus on dietary modification and the use of fluoride and pit and fissure sealants to increase the host resistance. Mutans streptococci (MS) in particular Streptococcus mutans is a major causative bacteria that are involved in dental ...