• The Korean Journal of Food And Nutrition
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• v.21 no.1
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• pp.56-63
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• 2008

This study investigated the quality characteristics of breads manufactured with xylito1. Four different concentrations(0, 5, 7, and 10%) of xylitol were added to the bread-making flour. Volume, color, the visco-elastic properties of the dough, and bread texture were analyzed. The dough volumes of the xylitol treatments during fermentation, as well as the final volumes of the xylitol breads were lower than those of the control dough and bread. Onset temperature slightly increased with the xylitol concentration, but entalphy changed minimally. Finally, the hardness of the bread positively increased with the xylitol concentration.

• Journal of Microbiology
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• v.44 no.1
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• pp.113-120
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• 2006

Candida tropicalis was treated with ultraviolet (UV) rays, and the mutants obtained were screened for xylitol production. One of the mutants, the UV1 produced 0.81g of xylitol per gram of xylose. This was further mutated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), and the mutants obtained were screened for xylitol production. One of the mutants (CT-OMV5) produced 0.85g/g of xylitol from xylose. Xylitol production improved to 0.87 g/g of xylose with this strain when the production medium was supplemented with urea. The CT-OMV5 mutant strain differs by 12 tests when compared to the wild-type Candida tropicalis strain. The XR activity was higher in mutant CT-OMV5. The distinct difference between the mutant and wild-type strain is the presence of numerous chlamvdospores in the mutant. In this investigation, we have demonstrated that mutagenesis was successful in generating a superior xylitol-producing strain, CT-OMV5, and uncovered distinctive biochemical and physiological characteristics of the wild-type and mutant strain, CT-OMV5.

• Journal of Microbiology and Biotechnology
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• v.13 no.5
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• pp.725-730
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• 2003

Three recombinant Saccharomyces cerevisiae strains showing different levels of xylose reductase activity were constructed to investigate the effects of xylose reductase activity and glucose feed rate on xylitol production. Conversion of xylose to xylitol is catalyzed by xylose reductase of Pichia stipitis with cofactor NAD(P)H. A two-substrate fermentation strategy has been employed where glucose is used as an energy source for NADPH regeneration and xylose as substrate for xylitol production. All recombinant S. cerevisiae strains Yielded similar specific xylitol productivity, indicating that xylitol production in the recombinant S. cerevisiae was more profoundly affected by the glucose supply and concomitant It generation of cofactor than the xylose reductase activity itself. It was confirmed in a continuous culture that the elevation of the glucose feeding level in the xylose-conversion period enhanced the xylitol productivity in the recombinant S. cerevisiae.

• Journal of Oral Medicine and Pain
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• v.41 no.4
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• pp.155-160
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• 2016

Purpose: It has been reported that xylitol and sorbitol affect antifungal activities by enhancing antimicrobial activities of other substances. The purpose of this study was to investigate the direct candidacidal activities of xylitol and sorbitol at a wide range of concentration. Methods: Xylitol and sorbitol solubilized with simulated salivary buffer at a range of $0.8{\mu}M$ to 1.05 M were used. Candida albicans strains, ATCC strains 10231, 11006, and 18804 were used for the candidacidal assay. The candidacidal activities of xylitol and sorbitol were determined by comparing the numbers of colony forming units between in the presence and absence of xylitol or sorbitol and calculating the percent loss of cell viability. Results: There were some differences in the candidacidal activities according to the types of sugar alcohols and C. albicans strains. The candidacidal activity of more than 10% was observed when a final concentration of 32.9 mM in xylitol or sorbitol was maintained and that of about 20% was observed when a final concentration of 131 mM was maintained. Even at a high concentration of 1.05 M, the candidacidal activity of xylitol or sorbitol was about 20%. Conclusions: Xylitol and sorbitol at the concentrations used in commercial oral health care products had some levels of candidacidal activities.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.4
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• pp.561-567
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• 2002

Xylitol is a 5-carbons carbohydrate, which can be replaced with sucrose for preventing caries. The replication of Streptococcus mutans and its formation of artificial plaque were studied in the media containing xylitol. The combined effect of xylitol and other carbohydrates on Streptococcus mutans was also studied. The replication of Streptococcus mutans was inhibited according to the increased concentration of xylitol. Streptococcus mutans replicated at the initial stage of incubation in the media containing glucose, fructose or lactose, while replicating from the beginning of incubation in the media containing fructose as combining with xylitol. The formation of artificial plaque by Streptococcus mutans was significantly reduced in the media containing with xylitol and fructose. These results indicated that the replication of Streptococcus mutans was inhibited according to the increased concentration of xylitol, and the formation of artificial plaque by Streptococcus mutans was significantly inhibited in the media containing xylitol and fructose.

• Journal of Korean society of Dental Hygiene
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• v.15 no.2
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• pp.311-317
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• 2015

Objectives: The purpose of this study was to identify the effects of xylitol and sorbitol mouth rinse on the salivary caries activity levels. Methods: The study subjects were 38 female college students in Gyeongju, Korea. The subjects visited the institution once a week for 4 weeks and the saliva samples were measured for the amount of salivary caries activity levels. The saliva was collected 5 times and incubated in Mitis Salivarius Agar for 48 hours(VS-1203P3L, Vision, Korea) and measured. Results: The Streptococcus mutans CFU decreased by statistically significant amounts as compared to before the experiment within the xylitol group and the sorbitol group(p<0.01). After three weeks of mouth rinse application, Streptococcus mutans CFU of the xylitol group and the sorbitol group showed statistically significant differences(p<0.05). The salivary flow rates within the xylitol group and sorbitol group increased by statistically significant amounts(p<0.01) than before the test. The change in the salivary buffering capacity decreased by a statistically significant amount as compared to before experiment within the xylitol group(p<0.01). Conclusions: The salivary caries activity levels decreased after using xylitol and sorbitol mouth rinse in CFU and the flow rate. The buffering activity levels increased within the xylitol group. Further follow-up studies would be necessary to identify the various effects of xylitol.

• Restorative Dentistry and Endodontics
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• v.39 no.4
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• pp.288-295
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• 2014

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, combined susceptibility was evaluated using optimal inhibitory combinations (OIC), optimal bactericidal combinations (OBC), and fractional inhibitory concentrations (FIC). The anti-biofilm activity of xylitol and UA on Streptococcus spp. was evaluated by growing cells in 24-well polystyrene microtiter plates for the biofilm assay. Significant mean differences among experimental groups were determined by Fisher's Least Significant Difference (p < 0.05). Results: The synergistic interactions between xylitol and UA were observed against all tested strains, showing the FICs < 1. The combined treatment of xylitol and UA inhibited the biofilm formation significantly and also prevented pH decline to critical value of 5.5 effectively. The biofilm disassembly was substantially influenced by different age of biofilm when exposed to the combined treatment of xylitol and UA. Comparing to the single strain, relatively higher concentration of xylitol and UA was needed for inhibiting and disassembling biofilm formed by a mixed culture of S. mutans 159 and S. sobrinus 33478. Conclusions: This study demonstrated that xylitol and UA, synergistic inhibitors, can be a potential agent for enhancing the antimicrobial and anti-biofilm efficacy against S. mutans and S. sobrinus in the oral environment.

• KSBB Journal
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• v.17 no.4
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• pp.339-344
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• 2002

Flow injection analysis technique for monitoring of xylitol concentrations in biological processes has been developed using xylitol oxidase (XYO) immobilized on VA-Epoxy Biosynth carrier. The immobilized XYO cartridge has been integrated into a FIA system with an oxygen electrode and systematically investigated with regards to the factors which can affect the activity of the immobilized XYO, such as pH, temperature, salt concentration etc. The activity of the immobilized XYO increased with the temperature ($19.0 - 29.0^{circ}C$) and sample injection volume ($75-250\muL$) and molarity of potassium phosphate buffer (0.1-1 M), but it reached the highest value at pH 8.5. The XYO-FIA system has been also applied for on-line monitoring of xylitol concentrations in a reactor and showed good operational stability and agreement with off-line data measured with HPLC.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.4
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• pp.554-562
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• 2003

Xylitol has been used as sugar substitute to prevent dental caries. It is not fermented by most dental plaque bacteria and interferes with the growth of mutans streptococci. Therefore the production of acidic metabolites and the growth of mutans streptococci are inhibited. S. mutans strains which are inhibited to grow under the presence of xylitol are referred as xylitol-sensitive ($X^S$) strains. However, experimental and clinical studies have shown that there were mutated groups of S. mutans strains that are not affected by xylitol. They are referred as xylitol-resistant($X^R$) strains. The aim of the present study was to investigate that emergence of $X^R$ strain would effect on the anticariogenecity of xylitol by comparing the growth rate, the extracellular pH, hydroxyapatite adhesion and the agglutination of the $X^R/X^S$ strains. Overall we came out with following results : 1. No difference in the growth rate and the extracellular pH was found between the $X^S$ strain and the $X^R$ strain. 2. No difference in adhesion to hydroxyapatite surface was found between the $X^R$ strain and the $X^S$ strain (p>0.05) and adhesion of the $X^S$ strain was greater than that of $X^R$ strain in the sucrose-dependent adhesion to hydroxyapatite (p<0.05). 3. The $X^R$ strain was agglutinated in the lower concentration of saliva than that of $X^S$ strains.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.1
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• pp.84-88
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• 2002

The effect of dietary xylitol on growth performance and nitrogen retention was studied in male broiler chicks during immunological stimulation. In experiment 1, chicks (10 day of age) were fed a corn-soybean diet containing 10% glucose or 10% xylitol with identical metabolizable energy and crude protein for 14 days. In experiment 2, ten-day-old chicks were fed 10% glucose or 6% xylitol diet for 8 days. During the final 6 days of the experimental periods, a half of birds fed each diet were injected intraperitoneally with 0.5 mg/kg body weight of Escherichia coli lipopolysaccharide (LPS, 0127:B8) on days 1, 3 and 5, and with 250 mg/kg body weight of Sephadex-G50 superfine on days 2 and 4 to stimulate immune system in both experiments. Feeding of the xylitol diets partially prevented the reduction in body weight gain or feed efficiency due to LPS and Sephadex injections, but the glucose diet did not in both the experiments. LPS and Sephadex injections decreased nitrogen retention, whereas the diet containing xylitol partly in experiment 1 and almost completely in experiment 2, prevented the reduction due to immunological stimulation. These results indicate that dietary xylitol probably prevents the reduction in nitrogen retention with growth retardation due to LPS and Sephadex injection. The beneficial effect on nitrogen retention is obtained when chicks are given xylitol 2 days before stimulating the immune system.