Publications by authors named "Taketo Kawarai"

Hexanol is a volatile alcohol and a major component of plant essential oils (EOs). However, the antibacterial activity of hexanol vapor has not been well studied. This study aimed to evaluate the antibacterial activity of hexanol.

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We investigated the effect of xylitol or/and funoran on biofilm formation by Streptococcus mutans, one of cariogenic bacteria, on the surfaces coated and non-coated with saliva. Effects of xylitol and/or funoran were observed on biofilm formation of S. mutans in non-coated and salivary components-coated polystyrene microtiter 96-well plates (s-plate) and flow cell system.

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Japanese horse mackerel () is an important marine resource, and its loss and waste should be reduced. This study aimed to identify the changes in the microflora composition during storage and specific spoilage organisms (SSOs) in Japanese horse mackerel, for spoilage prevention. They were stored at either 20 °C or 4 °C aerobically, and the bacterial viable counts, concentration of total volatile basic nitrogen (TVB-N), and microflora composition for each group were analyzed.

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Kabura-zushi is a traditional Japanese fermented food made from yellowtail, rice, salt, and kōji. In this study, the complete genomic sequence of Lactobacillus curvatus NFH-Km12, isolated from this unique food, is reported. NFH-Km12 has a 1.

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Aggregatibacter actinomycetemcomitans is an oral pathogen for aggressive periodontitis, and encodes a triheme c-containing membrane-bound enzyme, quinol peroxidase (QPO) that catalyzes peroxidase activity using quinol in the respiratory chain. In the previous work, we have characterized recombinant QPO purified from the membrane fraction of Escherichia coli harboring a plasmid containing QPO gene. Irreversible inactivation of QPO by high concentration of H2O2 exhibited pseudo-first order kinetics.

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Adhesion of oral mitis group streptococci, such as Streptococcus gordonii, to acquired pellicle on the tooth surface is the first step in oral biofilm formation. S. gordonii strain DL1 possesses an Hsa adhesin, which recognizes the terminal sialic acid of host sialoglycoconjugates.

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Objective: Streptococcus mutans, a gram-positive oral bacterium, has been identified as one of the principal etiological agents of human dental caries. To clarify the nature of the difference anti-biofilm effect against S. mutans between Assam tea from Camellia sinensis var.

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Physical fitness is an indicator of systemic well-being in humans. Little is known about the role of physical fitness for maintaining systemic health in the elderly. Here, we study elderly subjects to determine the relationships between physical fitness and CD56 and CD16 surface NK cell markers on peripheral blood lymphocytes, as well as to analyze the relationship between the surface markers and incidence of death.

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The production of water-insoluble glucan (WIG) enables Streptococcus mutans to survive and persist in the oral niche. WIG is produced from sucrose by glucosyltransferase encoded tandemly by the highly homologous gtfB and gtfC genes. Conversely, a single hybrid gene from the endogenous recombination of gtfB and gtfC is easily generated using RecA, resulting in S.

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The oral microbial flora consists of many beneficial species of bacteria that are associated with a healthy condition and control the progression of oral disease. Cooperative interactions between oral streptococci and the pathogens play important roles in the development of dental biofilms in the oral cavity. To determine the roles of oral streptococci in multispecies biofilm development and the effects of the streptococci in biofilm formation, the active substances inhibiting Streptococcus mutans biofilm formation were purified from Streptococcus salivarius ATCC 9759 and HT9R culture supernatants using ion exchange and gel filtration chromatography.

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Traditional brewing of Fukuyama pot vinegar is a process that has been continued in Fukuyama, Kagoshima, Japan, for almost 200 years. The entire process proceeds from raw materials, including steamed rice, rice koji (steamed rice grown with a fungus, Aspergillus oryzae) and water, to produce vinegar in roughly capped large pots laid in the open air. No special fermentative manipulation is required, except for scattering dried rice koji (called furi-koji) on the surface of the mash to form a cap-like mat on the surface at the start of brewing.

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The non-obese diabetic mouse (NOD) is the most characterized model used to study insulin-dependent type 1 diabetes mellitus (IDDM) and Sjoögren's syndrome (SS). In a previous report, we found NOD.E2f1(-/-) mice show a greater progressive development to IDDM and SS compared to NOD mice.

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The fungal pathogen Candida albicans is an opportunistic fungal pathogen that causes oral and vaginal mucosal infections as well as systemic disease. The ability of C. albicans to adhere to host surfaces is positively correlated with its pathogenicity.

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Article Synopsis
  • - The study investigated how high hydrostatic pressure (HPT) at 75 MPa for 30 minutes caused a phenomenon called HPT-induced chromosome condensation (HPT-CC) in the yeast Schizosaccharomyces pombe, leading to compacted chromosomal DNA without significantly affecting cell viability.
  • - HPT-CC was reversible, as the condensed state returned to normal when the treated cells were cultured post-treatment, and its occurrence was not linked to changes in the nuclear envelope or the cell cycle.
  • - The research found that HPT-CC was also present in another yeast, Saccharomyces cerevisiae, suggesting it acts as a temporary stress response mechanism to high hydrostatic pressure across yeast species.
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High osmotic environments produced by NaCl or sucrose have been used as reliable and traditional methods of food preservation. We tested, Escherichia coli as an indicator of food-contaminating bacterium, to determine if it can form biofilm in a hyperosmotic environment. E.

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We investigated the effects of skimmed milk and its protein fractions (casein, whey, globulin, and albumin) on the injury and inactivation of Escherichia coli K-12 by high hydrostatic pressure (HHP) treatment. The protective effect of skimmed milk on HHP-mediated inactivation and injury of E. coli increased with increases in the skimmed milk concentration.

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On the basis of our previous study concerning the effect of high hydrostatic pressure treatment (HPT) on Escherichia coli FtsZ ring (bacterial cytoskeleton) formation, we aimed to determine the effect of HPT on the growth properties of a representative eukaryotic microbe, Schizosaccharomyces pombe, in relation to the behavior of genuine cytoskeletons. Microtubules were visualized with GFP-linked alpha-tubulin. Actin-related cytoskeletons were fluorescently stained with rhodamine-phalloidin.

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While studying the mechanism by which high-pressure carbon dioxide treatment (HCT) inactivates bacteria, we found that the efficiency of DNA recovery via phenol extraction was extraordinarily low from E. coli K12 cells that had been subjected to HCT. DAPI staining of the treated cells, however, revealed that nuclear DNA was present.

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We found that species combinations such as Lactobacillus casei subsp. rhamnosus IFO3831 and Saccharomyces cerevisiae Kyokai-10 can form a mixed-species biofilm in coculture. Moreover, the Kyokai-10 yeast strain can form a biofilm in monoculture in the presence of conditioned medium (CM) from L.

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We previously reported that the postgrowth of Escherichia coli K-12 after high-hydrostatic-pressure treatment (HPT) as moderate as 75 MPa for 30 min at 37 degrees C induced the formation of elongated cells due to an HPT-induced disorder in FtsZ ring formation, which is essential for cell division. Because an FtsZ ring is known as a bacterial cytoskeleton, we examined the effect of HPT on a eukaryotic cytoskeleton, such as actin cables (long bundles of actin filaments), of Saccharomyces cerevisiae. We found that actin cables disappeared after HPT (100 MPa) and were not reorganized until 3.

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We reported previously that high hydrostatic pressure-injured stationary phase cells of Escherichia coli K-12 lost their intrinsic deoxycholate tolerance. The AcrAB-TolC multi-drug resistance pump driven by proton motive force has been argued to be responsible for the tolerance to deoxycholate. In this report, we tested the sensitivity of the AcrAB-TolC (three components) pump to high hydrostatic pressure treatment (HPT).

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Effects of the clumping of bacterial spores on their heat resistance as a result of heat treatment were investigated. Spore suspensions of Bacillus cereus, Bacillus coagulans and Bacillus licheniformis were heated at 85 degrees C. Survivor curves of the three strains showed tailing in all treatments after 30 min.

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