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1.
Ringø E Lødemel JB Myklebust R Kaino T Mayhew TM Olsen RE 《Journal of applied microbiology》2001,90(2):294-300
AIMS: The primary aim was to use transmission electron microscopy (TEM) and scanning electron microscopy (SEM) to define the location of epithelium-associated bacteria in the digestive tract of the salmonid fish, Arctic charr (Salvelinus alpinus). METHODS AND RESULTS: TEM and SEM examination of the gastrointestinal tract demonstrated substantial numbers of ovoid and rod-shaped bacterial cells associated with the microvillous brush borders of enterocytes. Bacteria were found at the tips of microvilli as well as between adjacent microvilli. Endocytosis of bacteria by epithelial cells was observed in two regions (pyloric caeca and midgut). CONCLUSION: Electron microscope examination of the gut is an important tool for evaluating the microbial ecology of the fish digestive tract ecosystem. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of the current study clearly demonstrate that the intestine is involved in bacterial endocytosis. 相似文献
2.
In response to osmotic stress, proline is accumulated in many bacterial and plant cells. During various stresses, the yeast
Saccharomyces cerevisiae induces glycerol or trehalose synthesis, but the fluctuations in gene expression and intracellular levels of proline in yeast
are not yet well understood. We previously found that proline protects yeast cells from damage by freezing, oxidative, or
ethanol stress. In this study, we examined the relationships between the gene expression profiles and intracellular contents
of glycerol, trehalose, and proline under stress conditions. When yeast cells were exposed to 1 M sorbitol stress, the expression
of GPD1 encoding glycerol-3-phosphate dehydrogenase is induced, leading to glycerol accumulation. In contrast, in the presence of
9% ethanol, the rapid induction of TPS2 encoding trehalose-6-phosphate phosphatase resulted in trehalose accumulation. We found that intracellular proline levels
did not increase immediately after addition of sorbitol or ethanol. However, the expressions of genes involved in proline
synthesis and degradation did not change during exposure to these stresses. It appears that the elevated proline levels are
due primarily to an increase in proline uptake from a nutrient medium caused by the induction of PUT4. These results suggest that S. cerevisiae cells do not accumulate proline in response to sorbitol or ethanol stress different from other organisms. 相似文献
3.
Self-Cloning Baker's Yeasts That Accumulate Proline Enhance Freeze Tolerance in Doughs 总被引:1,自引:0,他引:1 下载免费PDF全文
Tomohiro Kaino Tetsuya Tateiwa Satomi Mizukami-Murata Jun Shima Hiroshi Takagi 《Applied microbiology》2008,74(18):5845-5849
We constructed self-cloning diploid baker's yeast strains by disrupting PUT1, encoding proline oxidase, and replacing the wild-type PRO1, encoding γ-glutamyl kinase, with a pro1(D154N) or pro1(I150T) allele. The resultant strains accumulated intracellular proline and retained higher-level fermentation abilities in the frozen doughs than the wild-type strain. These results suggest that proline-accumulating baker's yeast is suitable for frozen-dough baking. 相似文献
4.
Monica Olsen Reidar Myklebust Turid Kaino Vibeke Elbrønd Svein Mathiesen 《Polar Biology》2002,25(9):641-649
The aim of this study was to provide data on the morphology of the gastrointestinal tract of Adélie penguins (Pygoscelis adeliae). It was found to consist of a long oesophagus, a two-chambered stomach, a small intestine measuring only 5.22body length, two rudimentary caeca and a short colon, typical of carnivorous birds. The stomach comprised a glandular proventriculus and a muscular gizzard that frequently contained grit. An acidic pH was recorded in both chambers. Ultrastructural studies of the small intestinal mucosal membrane revealed epithelial cells with elongated, irregular microvilli and high affinity for toluidine blue, absorptive intestinal epithelial cells and goblet cells. Numerous large lymphocyte-like cells were observed close to the brush border of the epithelium, and empty spaces on the epithelial surface reflected normal cell loss in the small intestine. The rudimentary caeca and colon provide relatively little volume and time for symbiotic bacteria to aid the digestion of crustacean chitin. 相似文献
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6.
Kaino T Tateiwa T Mizukami-Murata S Shima J Takagi H 《Applied and environmental microbiology》2008,74(18):5845-5849
We constructed self-cloning diploid baker's yeast strains by disrupting PUT1, encoding proline oxidase, and replacing the wild-type PRO1, encoding gamma-glutamyl kinase, with a pro1(D154N) or pro1(I150T) allele. The resultant strains accumulated intracellular proline and retained higher-level fermentation abilities in the frozen doughs than the wild-type strain. These results suggest that proline-accumulating baker's yeast is suitable for frozen-dough baking. 相似文献
7.
Shuji Udagawa Satoshi Sakami Takahiro Takemura Mikiya Sato Takahiro Arai Aiko Nitta Takumi Aoki Koji Kawai Tomokatsu Iwamura Seiji Okazaki Takehiro Takahashi Mie Kaino 《Bioorganic & medicinal chemistry letters》2013,23(6):1617-1621
A series of novel 5-trans-hydroxyadamantan-2-yl-5,6,7,8-tetrahydropyrazolo[4,3-c]azepin-4(1H)-ones that inhibit 11beta-hydroxysteroid dehydrogenase type 1 are described. We discovered these 7-membered cyclic amide derivatives by introducing a distinctive linker through pharmacophore analysis of known ligands included in X-ray co-crystal structures. Further optimization using docking studies led to highly potent inhibitors 15b and 27, which furthermore showed the potent efficacy in in vivo studies. 相似文献
8.
Orally administered bovine lactoferrin inhibits bacterial translocation in mice fed bovine milk. 总被引:4,自引:0,他引:4 下载免费PDF全文
S Teraguchi K Shin T Ogata M Kingaku A Kaino H Miyauchi Y Fukuwatari S Shimamura 《Applied microbiology》1995,61(11):4131-4134
Feeding of bovine milk to mice induced a high incidence of bacterial translocation from the intestines to the mesenteric lymph nodes, and the bacteria involved were mainly members of the family Enterobacteriaceae. Supplementation of the milk diet with bovine lactoferrin or a pepsin-generated hydrolysate of bovine lactoferrin resulted in significant suppression of bacterial translocation. Our findings suggest that this ability of lactoferrin to inhibit bacterial translocation may be due to its suppression of bacterial overgrowth in the guts of milk-fed mice. 相似文献
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10.
Yuzy Matsuo Kouhei Nishino Kouhei Mizuno Takashi Akihiro Takashi Toda Yasuhiro Matsuo Tomohiro Kaino Makoto Kawamukai 《PloS one》2013,8(3)
Polypeptone is widely excluded from Schizosaccharomyces pombe growth medium. However, the reasons why polypeptone should be avoided have not been documented. Polypeptone dramatically induced cell lysis in the ura4 deletion mutant when cells approached the stationary growth phase, and this phenotype was suppressed by supplementation of uracil. To determine the specificity of this cell lysis phenotype, we created deletion mutants of other genes involved in de novo biosynthesis of uridine monophosphate (ura1, ura2, ura3, and ura5). Cell lysis was not observed in these gene deletion mutants. In addition, concomitant disruption of ura1, ura2, ura3, or ura5 in the ura4 deletion mutant suppressed cell lysis, indicating that cell lysis induced by polypeptone is specific to the ura4 deletion mutant. Furthermore, cell lysis was also suppressed when the gene involved in coenzyme Q biosynthesis was deleted. This is likely because Ura3 requires coenzyme Q for its activity. The ura4 deletion mutant was sensitive to zymolyase, which mainly degrades (1,3)-beta-D glucan, when grown in the presence of polypeptone, and cell lysis was suppressed by the osmotic stabiliser, sorbitol. Finally, the induction of cell lysis in the ura4 deletion mutant was due to the accumulation of orotidine-5-monophosphate. Cell wall integrity was dramatically impaired in the ura4 deletion mutant when grown in the presence of polypeptone. Because ura4 is widely used as a selection marker in S. pombe, caution needs to be taken when evaluating phenotypes of ura4 mutants. 相似文献