Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
Volume 71 , Issue 10
Showing 1-44 articles out of 44 articles from the selected issue
Award Reviews
  • Fumiyoshi ABE
    2007 Volume 71 Issue 10 Pages 2347-2357
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
    JOURNALS FREE ACCESS
    The discovery of piezophiles (previously referred to as barophiles) prompted researchers to investigate the survival strategies they employ in high-pressure environments. There have been innovative high-pressure studies on biological processes applying modern techniques of genetics and molecular biology in bacteria and yeasts as model organisms. Recent advanced studies in this field have shown unexpected outcomes in microbial growth, physiology and survival when living cells are subjected to high hydrostatic pressure. The effects are conceptually dependent on the sign and magnitude of volume changes associated with any chemical reaction in the cells. Nevertheless, it is difficult to explain the pressure effects on complex metabolic networks based on a simple volume law. The challenges in piezophysiology are to discover whether the physiological responses of living cells to high pressure are relevant to their growth and to identify the critical factors in cell viability and lethality under high pressure from the general and organism-specific viewpoints.
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  • Yoshimasa TAKAHASHI
    2007 Volume 71 Issue 10 Pages 2358-2366
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
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    B-cell memory has been extensively analyzed in the systemic immune response elicited by hapten-carrier antigens, and the regulatory mechanisms underlying the process are beginning to be elucidated. Memory B cells can be generated through heterogeneous pathways within and outside germinal centers (GCs). Once developed, they appear to be maintained like stem cells for long periods by homeostatic proliferation. In response to reencountered antigens, memory B cells robustly secrete antibodies with help of the anti-apoptotic effect of Ras-mediated signals. We have recently found that following intranasal infection with an influenza virus, virus-specific memory B cells develop in the lungs and persist for a long time along with GC B cells and plasma cells; this appears to be unique feature of the mucosal memory response. Thus memory B cell responses in the systemic and mucosal sites are regulated by distinct processes and further understanding of them should provide a theoretical framework for the development of new vaccine strategies.
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  • Hidefumi MAKABE
    2007 Volume 71 Issue 10 Pages 2367-2374
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
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    Synthetic studies of annonaceous acetogenins starting from (−)-muricatacin (1a) or (+)-muricatacin are described, involving (−)-muricatacin (1a), mono-THF acetogenin, solamin (2), reticulatacin (3), (15R, 16R, 19S, 20S)-cis-solamin (4a) and (15S, 16S, 19R, 20R)-cis-solamin (4b), non-adjacent bis-THF acetogenin, 4-deoxygigantecin (5), and epoxide-bearing acetogenin, (15S, 16R, 19S, 20R)-diepomuricanin (6a).
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Analytical Chemistry Regular Paper
  • Wichai CHERDSHEWASART, Suttijit SRIWATCHARAKUL
    2007 Volume 71 Issue 10 Pages 2527-2533
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
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    Pueraria mirifica is a tuberous plant enriched with active phytoestrogens. There is no established information about the factors influencing isoflavonoid storage in the tubers. We investigated the tuberous storage of the major isoflavonoids of 1-year-old plants. Four cultivars of P. mirifica were cultivated in the same field trial during the same period to establish a unique plant age and differentiation under the same environment and soil conditions. The tubers collected from the 1-year-old plants in the summer, rainy season and winter were submitted to an HPLC analysis with a gradient system comprising 0.1% acetic acid and acetonitrile. Five major isoflavonoids, puerarin, daidzin, genistin, daidzein and genistein, were adopted as standards. P. mirifica tubers of different cultivars collected in the same season exhibited significant differences in individual and total isoflavonoid contents, showing chemovariety. P. mirifica tubers of the same cultivar collected from different seasons also exhibited significant differences in individual and total isoflavonoid contents, showing the influence of season. In conclusion, the tuberous storage of major isoflavonoids in 1-year-cultivated plants was greatly diverse and was strongly influenced by the season and plant genetics.
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Organic Chemistry Regular Paper
  • Miwa SAKAI, Hiroshi HIRATA, Hironori SAYAMA, Kazuya SEKIGUCHI, Hiroaki ...
    2007 Volume 71 Issue 10 Pages 2408-2419
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
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    We investigated the biosynthetic pathway for 2-phenylethanol, the dominant floral scent compound in roses, using enzyme assays. L-[2H8] Phenylalanine was converted to [2H8] phenylacetaldehyde and [2H8]-2-phenylethanol by two enzymes derived from the flower petals of R. ‘Hoh-Jun,’ these being identified as pyridoxal-5′-phosphate-dependent L-aromatic amino acid decarboxylase (AADC) and phenylacetaldehyde reductase (PAR). The activity of rose petal AADC to yield phenylacetaldehyde was nine times higher toward L-phenylalanine than toward its D-isomer, and this conversion was not inhibited by iproniazid, a specific inhibitor of monoamine oxidase. Under aerobic conditions, rose petal AADC stoichiometrically produced NH3 together with phenylacetaldehyde during the course of decarboxylation and oxidation, followed by the hydrolysis of L-phenylalanine. Phenylacetaldehyde was subsequently converted to 2-phenylethanol by the action of PAR. PAR showed specificity toward several volatile aldehydes.
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Organic Chemistry Notes
Biochemistry & Molecular Biology Regular Papers
  • Kouichi NOZAKI, Takahiro SEKI, Keiko MATSUI, Masahiro MIZUNO, Takahisa ...
    2007 Volume 71 Issue 10 Pages 2375-2382
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
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    Trametes hirsuta produced cellulose-degrading enzymes when it was grown in a cellulosic medium such as Avicel or wheat bran. An endo-β-1,4-glucanase (ThEG) was purified from the culture filtrate, and the gene and the cDNA were isolated. The gene consisted of an open reading frame encoding 384 amino acids, interrupted by 11 introns. The whole sequence showed high homology with that of family 5 glycoside hydrolase. The properties of the recombinant enzyme (rEG) in Aspergillus oryzae were compared with those of the En-1 from Irpex lacteus, which showed the highest homology among all the endoglucanases reported. The rEG activity against Avicel was about 8 times higher than that of En-1 when based on CMC degradation. A remarkable structural difference between the two enzymes was the length of the linker connecting the cellulose-binding domain to the catalytic domain.
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  • Yan-Hong SI, Ming-Gang FANG, Yi HUANG, Fang-Liang ZHENG, Ting LI, Zhi- ...
    2007 Volume 71 Issue 10 Pages 2435-2441
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
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    Genetically modified baculoviruses offer a promising alternative to chemical insecticides in the control of agricultural and forest insect pests. A novel bacmid, HaBacYH6, was constructed in which the ecdysteroid UDP-glucosyltransferase gene (egt) was replaced with a bacterial replication cassette containing a mini-F replicon, a kanamycin resistance gene, and the attTn7 site. Insertion of the enhanced green fluorescence protein gene (egfp) into HaBacYH6 showed that the bacmid can express an active exogenous protein. Bioassays showed that median lethal time (LT50) of HaBacYH6 was 89.23 h in third instar Helicoverpa armigera larvae, 15.81 h earlier than that of wild-type HearNPV-G4, though there was no significant difference in median lethal dose (LD50). The data indicate that HaBacYH6 can be used as a new Bac-to-Bac system, and can also provide a technology platform for generating more effective biological insecticides.
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  • Pornanong ARAMWIT, Areeporn SANGCAKUL
    2007 Volume 71 Issue 10 Pages 2473-2477
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
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    Sericin has good hydrophilic properties, compatibility, and biodegradation, it can be used as a wound-healing agent. We evaluated the effects of sericin on wound healing and wound size reduction using rats by generating two full-thickness skin wounds on the dorsum. Group 1 animals were treated with Betadine® on left-side (control) wounds and, with 8% sericin cream on right-side (treated) wounds. Group 2, cream base (formula control) and 8% sericin cream (treated) were topically applied to left-, and right-side wounds respectively. Sericin-treated wounds had much smaller inflammatory reactions, and wound-size reduction was much greater than in the control throughout the inspection period. Mean time in days for 90% healing from sericin-treated wounds was also much less than for cream base-treated wounds. Histological examination after 15 d of treatment with 8% sericin cream revealed complete healing, no ulceration, and an increase in collagen as compared to cream base-treated wounds, which showed some ulceration and acute inflammatory exudative materials.
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  • Ittipon SAICHANA, Yoshitaka ANO, Osao ADACHI, Kazunobu MATSUSHITA, Hir ...
    2007 Volume 71 Issue 10 Pages 2478-2486
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
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    For easy measurement of 5-keto D-gluconate (5KGA) and 2-keto D-gluconate (2KGA), two enzymes, 5KGA reductase (5KGR) and 2KGA reductase (2KGR) are useful. The gene for 5KGR has been reported, and a corresponding gene was found in the genome of Gluconobacter oxydans 621H and was identified as GOX2187. On the other hand, the gene for 2KGR was identified in this study as GOX0417 from the N-terminal amino acid sequence of the partially purified enzyme. Several plasmids were constructed to express GOX2187 and GOX0417, and the final constructed plasmids showed good expression of 5KGR and 2KGR in Escherichia coli. From the two E. coli transformants, large amounts of each enzyme were easily prepared after one column chromatography, and the preparation was ready to use for quantification of 5KGA or 2KGA.
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  • Eiji MASAI, Yuko YAMAMOTO, Tomohiko INOUE, Kazuhiro TAKAMURA, Hirofumi ...
    2007 Volume 71 Issue 10 Pages 2487-2492
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
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    The vanillin dehydrogenase gene (ligV), which conferred the ability to transform vanillin into vanillate on Escherichia coli, was isolated from Sphingomonas paucimobilis SYK-6. The ligV gene consists of a 1,440-bp open reading frame encoding a polypeptide with a molecular mass of 50,301 Da. The deduced amino acid sequence of ligV showed about 50% identity with the known vanillin dehydrogenases of Pseudomonas vanillin degraders. The gene product of ligV (LigV) produced in E. coli preferred NAD+ to NADP+ and exhibited a broad substrate preference, including vanillin, benzaldehyde, protocatechualdehyde, m-anisaldehyde, and p-hydroxybenzaldehyde, but the activity toward syringaldehyde was less than 5% of that toward vanillin. Insertional inactivation of ligV in SYK-6 indicated that ligV is essential for normal growth on vanillin. On the other hand, growth on syringaldehyde was only slightly affected by ligV disruption, indicating the presence of a syringaldehyde dehydrogenase gene or genes in SYK-6.
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  • Nobuhiro AZUMA, Kyoko KANAMARU, Akinori MATSUSHIKA, Takafumi YAMASHINO ...
    2007 Volume 71 Issue 10 Pages 2493-2502
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
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    His-Asp phosphorelays are widespread signal transduction mechanisms in bacteria, fungi, and higher plants. In order to investigate a His-Asp phosphorelay network in filamentous fungi, which has been genetically characterized in part, we attempted to construct an in vitro phosphotransfer network in Aspergillus nidulans comprising all the necessary components. As a first step, we established an in vitro phosphotransfer system with a histidine-containing phosphotransmitter YpdA, a response regulator SrrA, and a bacterial histidine kinase ArcB as a phosphate donor. We demonstrated the phosphotransfer from ArcB to A. nidulans YpdA and the subsequent transfer from YpdA to SrrA. This is the first direct biochemical evidence for the presence of the phosphotransfer system in filamentous fungi. Furthermore, a retrograde phosphorylation from YpdA to FphA, a histidine kinase similar to bacterial phytochrome, was found. The overall picture of the His-Asp phosphorelays in A. nidulans is discussed based on the results of the in vitro study.
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  • Kazunori YAMADA, Takashi SHIBUYA, Masashi NODA, Nozomi UCHIYAMA, Ayumi ...
    2007 Volume 71 Issue 10 Pages 2503-2510
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
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    Enzymatic treatment of o-, m-, and p-chlorophenols and o-, m-, and p-cresols from artificial wastewater was undertaken through the enzymatic conversion into the corresponding phenoxy radicals with horseradish peroxidase (HRP) and nonenzymatic radical coupling reaction. The concentration of chlorophenols and cresols decreased sharply over the reaction time and water-insoluble oligomer precipitates were generated. The optimum conditions were determined to be the H2O2 concentration of 2.5 mM and poly(ethylene glycol) with molecular mass of 1.0×104 (10K-PEG) of 0.10 mg/cm3 at 30 °C for treatment of p-chlorophenol at 2.5 mM. The optimum pH values depended on the relative position of a chlorine atom for chlorophenols and on a methyl group for cresols. Concentrations of HRP and 10K-PEG were increased to 1.0 U/cm3 and 1.0 mg/cm3 respectively to treat m-chlorophenol highly. For o-chlorophenol, a decrease in the pH value to 3.0 after the enzymatic treatment led to the enhancement of the aggregation of oligomer precipitates. The % residual value for o-cresol effectively decreased by absorbing water-soluble intermediates on the chitosan films. These results indicate that chlorophenols and cresols were removed to a great degree by this technique, although the detailed procedure depended on the position of substituent groups of chlorophenols and cresols.
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  • Yasuhiro ARII, Hidenori YAMAGUCHI, Shin-Ichi FUKUOKA
    2007 Volume 71 Issue 10 Pages 2511-2514
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
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    The physiological function of prion proteins (PrP) remains unclear. To investigate the physiological relevance of PrP, we constructed a fusion protein of PrP with enhanced blue fluorescent protein (PrP-EBFP) to quantify the interaction of PrP with other molecules. Production of soluble PrP-EBFP was achieved by lowering the expression temperature in Escherichia coli (E. coli) cells to 15 °C. Soluble PrP-EBFP was purified on cation exchange and heparin-affinity columns to yield high purity protein. This is the first report of the preparation of soluble recombinant PrP without refolding following solubilization using denaturants or disruption using detergents. To confirm the integrity of PrP-EBFP, anisotropy was estimated under physiological conditions in the presence of heparin, which interacts with PrP. The dissociation constant was determined to be 0.88±0.07 μM. PrP-EBFP should be useful in the quantification of PrP interactions with other molecules.
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  • Hiroki TSURUTA, Ryuhei HAYASHI, Hiroyuki OHKAWA, Nobuhide OHKATSU, Mas ...
    2007 Volume 71 Issue 10 Pages 2534-2542
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
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    Phospholipase D, with a molecular mass of 64 kDa, was purified from the psychrophile, Shewanella sp. The enzyme showed maximal activity at pH 7.8 and 40 °C in the presence of the Ca2+-ion, and its activity at 10 °C was 6.5% of maximum. The enzyme exhibited high activity to the non-micelle form of phosphatidylcholine in an aqueous solution containing water miscible alcohols such as methanol, ethanol, iso-propanol, and n-propanol. Nucleotide sequencing of the enzyme gene yielded a deduced amino acid sequence, which showed 36.2% identity to that of Streptomyces chromofuscus phopsholipase D alone. The low sequence similarity to other phopsholipase D enzymes suggests that the purified enzyme might be a novel phospholipase D.
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  • Chiaki NAKANO, Akihiro MOTEGI, Tsutomu SATO, Masayuki ONODERA, Tsutomu ...
    2007 Volume 71 Issue 10 Pages 2543-2550
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
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    Sterol biosynthesis by prokaryotic organisms is very rare. Squalene epoxidase and lanosterol synthase are prerequisite to cyclic sterol biosynthesis. These two enzymes, from the methanotrophic bacterium Methylococcus capsulatus, were functionally expressed in Escherichia coli. Structural analyses of the enzymatic products indicated that the reactions proceeded in a complete regio- and stereospecific fashion to afford (3S)-2,3-oxidosqualene from squalene and lanosterol from (3S)-2,3-oxidosqualene, in full accordance with those of eukaryotes. However, our result obtained with the putative lanosterol synthase was inconsistent with a previous report that the prokaryote accepts both (3R)- and (3S)-2,3-oxidosqualenes to afford 3-epi-lanosterol and lanosterol, respectively. This is the first report demonstrating the existence of the genes encoding squalene epoxidase and lanosterol synthase in prokaryotes by establishing the enzyme activities. The evolutionary aspect of prokaryotic squalene epoxidase and lanosterol synthase is discussed.
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Biochemistry & Molecular Biology Notes
Food & Nutrition Science Regular Papers
  • Daniel RICO, Ana B. MARTÍN-DIANA, Catherine BARRY-RYAN, Gary T. ...
    2007 Volume 71 Issue 10 Pages 2383-2392
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
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    The thermal degradation kinetics of pectin methylesterase (PME) from carrot and lettuce were studied. Fresh extracts were exposed to temperatures from 55 to 70 °C until the enzyme was inactivated. A model based on the presence of two forms of the enzyme, one active and one non-active, is proposed. The natural variability of the PME activity was taken into the model in the form of normally distributed random effects. The common model parameters obtained (cleavage constant (0.0395±0.0062 s−1), degradation constant (0.556±0.112 s−1), cleavage energy of activation (469±23 kJ mol−1) and degradation energy of activation (488±18 kJ mol−1)) show that the PME degradation kinetics of the two vegetables can be explained with a single set of parameters.
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  • Masako YAJIMA, Junji HOSHIBA, Masaki TERAHARA, Takaji YAJIMA
    2007 Volume 71 Issue 10 Pages 2420-2427
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
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    The effect of early nutrition on the development of the immune tissue and T cells of mouse pups was examined. Newborn mice were divided into three experimental groups: mother-reared (MR) pups, pups that were fed on a milk substitute from the first day (AR-0), and the third day (AR-2), using a hand-feeding system. The average thymic size of the AR-2 pups was respectively significantly larger and smaller than that of the AR-0 and MR pups. In contrast, the splenic sizes of the AR-0 and AR-2 pups were greater than that of the MR pups. The numbers of CD4+CD8 and CD4CD8+ cells in the spleen of the MR pups were significantly higher than those in the AR-0 pups. These results indicate that early nutrition affected the sizes of the thymus and spleen and the composition of CD4+CD8 or CD4CD8+ T cells in the spleen.
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  • Shizue SAEGUSA, Mamoru TOTSUKA, Shuichi KAMINOGAWA, Tomohiro HOSOI
    2007 Volume 71 Issue 10 Pages 2428-2434
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
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    Candida albicans, Saccharomyces cerevisiae and their cell wall components, zymosan and glucan, have been shown to stimulate interleukin-8 (IL-8/CXCL-8) production by intestinal epithelial cell-like Caco-2 cells pre-cultured with 10 mM butyric acid. We examined in this study whether these yeasts also altered the production of other cytokines and cyclooxygenases (COXs) by Caco-2 cells. Culturing Caco-2 cells with 10 mM butyric acid and 15% FBS for 4 days enhanced the basal levels of mRNA encoding IL-6, IL-8, IL-18, monocyte chemoattractant protein (MCP)-1, stem cell factor, transforming growth factor (TGF)-β1, TGF-β3, tumor necrosis factor (TNF)-α, COX-1, and COX-2, but not of granulocyte-macrophage colony-stimulating factor (GM-CSF) and TGF-β2. The inclusion of live S. cerevisiae or C. albicans further enhanced the production of IL-8, but not of the other cytokines and COXs. The non-pathogenic yeasts, C. kefyr, C. utilis, C. versatilis, Kluyveromyces lactis, K. marxianus, Schizosaccharomyces pombe and Zygosaccharomyces rouxii, used for the production of fermented foods and probiotics, and the opportunistic pathogens, C. glabrata, C. krusei, C. parapsilosis and C. tropicalis, isolated from human tissue samples also enhanced IL-8 secretion by Caco-2 cells.
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  • Mihye KIM, Akira MURAKAMI, Hajime OHIGASHI
    2007 Volume 71 Issue 10 Pages 2442-2450
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
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    (−)-Epigallocatechin-3-gallate (EGCG), one of the main constituents of green tea, has been reported to function as an antioxidant with chemopreventive potential. In contrast, we have recently reported that EGCG enhanced pro-matrix metalloproteinase (MMP)-7 in HT-29 human colon cancer cells via spontaneous superoxide generation. In the present study, we examined the effects of dietary antioxidants on both spontaneous and EGCG-upregulated proMMP-7 production in HT-29 cells. Benzyl isothiocyanate (BITC), curcumin (CUR), gallic acid (GA), and N-acetyl-L-cysteine (NAC) reduced that production, while each alone did not have any effect on spontaneous production. None of the dietary factors suppressed EGCG-induced hydrogen peroxide generation in the media tested, whereas BITC, GA, and NAC inhibited the EGCG-enhanced activator protein (AP)-1 transcription activity by 126%, 77%, and 97%, respectively. Although CUR abolished the EGCG-upregulated MMP-7 mRNA expression, it unexpectedly enhanced the AP-1 activity by 502%, suggesting that this factor may disrupt the MMP-7 mRNA stabilization process. Together, our results indicate that dietary antioxidants modulate EGCG-induced MMP-7 production through different mechanisms.
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  • Shizuka TAMARU, Takayuki KURAYAMA, Masanobu SAKONO, Nobuhiro FUKUDA, T ...
    2007 Volume 71 Issue 10 Pages 2451-2457
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
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    Soybean protein isolate (SPI) was digested with protease to produce a peptides containing the low-molecular fraction (LD3) or a mixture of high- and low-molecular fractions (HD1). Rats were fed a diets containing SPI, LD3, or HD1 at a protein level equivalent to the 20% casein diet for 4 weeks. The serum triglyceride concentration was lower in rats fed SPI, LD3, and HD1 diets than in rats fed the casein diet, and the differences were significant for the cholesterol-enriched diet. The value for the LD3 group was the lowest among all groups for both the cholesterol-free and -enriched diets. The level of triglyceride in the post-perfused liver was significantly lower in the LD3 and HD1 groups and the SPI group than in the casein group irrespective of the presence of cholesterol in the diet. In the cholesterol-free diet, LD3 feeding as compared to casein feeding caused a reduction in triglyceride secretion from the liver to perfusate and an increment of hepatic ketone body production. The addition of cholesterol to the diets somewhat attenuated these effects of LD3. These results suggest that the low-molecular fraction in soybean peptides causes triglyceride-lowering activity through a reduction in triglyceride secretion from the liver to the blood circulation and the stimulation of fatty acid oxidation in the liver. There is a possibility that soybean peptides modulate triglyceride metabolism by changes in the hepatic contribution.
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  • Teruyuki USUI, Satoshi YANAGISAWA, Mio OHGUCHI, Miku YOSHINO, Risa KAW ...
    2007 Volume 71 Issue 10 Pages 2465-2472
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
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    The α-dicarbonyl compounds formed in the degradation of glucose and fructose were analyzed by HPLC using 2,3-diaminonaphthalene as derivatizing reagent, and identified as glucosone (GLUCO), 3-deoxyglucosone (3DG), 3-deoxyxylosone (3DX), tetrosone (TSO), triosone (TRIO), 3-deoxytetrosone (3DT), glyoxal (GO), and methylglyoxal (MGO). The results suggest that α-dicarbonyl compounds were formed from glucose via non-oxidative 3-deoxyglucosone formation and oxidative glucosone formation in glucose degradation. In addition, TRIO, GO, and MGO were also formed from glyceraldehyde as intermediate. The α-dicarbonyl compounds might be formed from glucose via these pathways in diabetes.
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  • Yoshiaki MIYAKE, Chihiro ITO, Masataka ITOIGAWA, Toshihiko OSAWA
    2007 Volume 71 Issue 10 Pages 2515-2521
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
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    Rice mold starters prepared from Aspergillus species are commonly used for the manufacture of koji in the production of oriental fermented foods. Methanol extracts of rice mold starters fermented by the Aspergillus species, A. awamori, A. kawachii, A. oryzae, A. saitoi, and A. sojae, were examined for their antioxidative activity by using a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging system. The extracts of A. awamori, A. kawachii, and A. saitoi exhibited higher activity than those of A. oryzae and A. sojae. An antioxidant was isolated from the extract of A. saitoi and identified as pyranonigrin-A by 1H-NMR, 13C-NMR, and FAB-MS analyses. The antioxidative activity of pyranonigrin-A was approximately equivalent to that of ferulic acid, an antioxidant in cereal grain. It was present in rice mold starters prepared by A. awamori, A. kawachii, and A. saitoi, although there was no pyranonigrin-A in the A. oryzae and A. sojae starters. The results suggest that the content of pyranonigrin-A in rice mold starters has a correlation with the antioxidative activity, and that it is induced in rice mold starters at the sporulation stage.
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  • Nobukazu ONISHI, Seiji KAWAMOTO, Kazuyuki UEDA, Yasushi YAMANAKA, Akik ...
    2007 Volume 71 Issue 10 Pages 2551-2556
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
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    Konjac is a traditional Japanese food with a peculiar texture, and it has been suggested that its main ingredient, konjac glucomannan (KGM), ameliorates metabolic disorders such as diabetes and hypercholesteremia. We have found that feeding with pulverized KGM (PKGM) prevents skin inflammation in a murine model of atopic dermatitis. Here, we show that dietary PKGM suppresses allergic rhinitis-like symptoms in mice upon immunization and nasal sensitization with ovalbumin (OVA). The PKGM-fed mice showed a much lower frequency of sneezing than in control animals. We also found that PKGM supplementation exclusively suppressed OVA-specific IgE response without affecting IgG1/IgG2a responses as well as systemic Th1/Th2 cytokine production. These results suggest that PKGM can be a beneficial foodstuff in preventing nasal allergy such as seasonal pollinosis.
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Food & Nutrition Science Notes
Food & Nutrition Science Communications
  • Bo ZHONG, Shunsuke SAKAI, Tohru SAEKI, Ryuhei KANAMOTO
    2007 Volume 71 Issue 10 Pages 2614-2617
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
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    We have hypothesized that rat liver serine dehydratase (SDH) is induced in response to the amount of surplus amino acids from dietary protein. In the present study, we found that excess leucine intake strongly induced SDH activity in the liver but not in the kidney of rats. The increase in activity was accompanied by increases in the levels of SDH mRNA. On the other hand, isoleucine and valine had little effect on SDH induction. These results support our hypothesis and suggest that leucine is a signal for SDH induction.
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  • Kousaku OHINATA, Shun AGUI, Masaaki YOSHIKAWA
    2007 Volume 71 Issue 10 Pages 2618-2621
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
    JOURNALS FREE ACCESS
    Based on the amino acid sequence YPFV found in the soy β-conglycinin β-subunit, which is common to an opioid peptide human β-casomorphin-4, peptides YPFVV, YPFVVN, and YPFVVNA were synthesized according to their primary structure. On guinea pig ileum (GPI) assay, they showed opioid activity (IC50 = 6.0, 9.2 and 13 μM respectively) more potent than human β-casomorphins, and were named soymorphins-5, -6, and -7, respectively. Their opioid activities on mouse vas deferens (MVD) assay were less potent than on GPI assay, suggesting that they are selective for the μ opioid receptor. Human β-casomorphin-4 and soymorphin-5 were released from the soy 7S fraction (β-conglycinin) by the action of gastrointestinal proteases. Soymorphins-5, -6, and -7 had anxiolytic activities after oral administration at doses of 10–30 mg/kg in the elevated plus-maze test in mice.
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Microbiology & Fermentation Technology Regular Papers
  • Shuichiro MURAKAMI, Haruka NISHIMOTO, Yosuke TOYAMA, Etsuko SHIMAMOTO, ...
    2007 Volume 71 Issue 10 Pages 2393-2401
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
    JOURNALS FREE ACCESS
    A newly isolated strain, 38C-2-1, produced alkaline and thermotolerant α-amylases and was identified as Bacillus halodurans. The enzymes were purified to homogeneity and named α-amylase I and II. These showed molecular masses of 105 and 75 kDa respectively and showed maximal activities at 50–60 °C and pH 10–11, and 42 and 38% relative activities at 30 °C. These results indicate that the enzymes are thermotolerant. The enzyme activity was not inhibited by a surfactant or a bleaching reagent used in detergents. A gene encoding α-amylase I was cloned and named amyI. Production of AmyI with a signal peptide repressed the growth of an Escherichia coli transformant. When enzyme production was induced by the addition of isopropyl β-D(−)-thiogalactopyranoside in the late exponential growth phase, the highest enzyme yield was observed. It was 45-fold that of the parent strain 38C-2-1.
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  • Tsuyoshi ABE, Takayuki HOSHINO, Akira NAKAMURA, Naoki TAKAYA
    2007 Volume 71 Issue 10 Pages 2402-2407
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
    JOURNALS FREE ACCESS
    Reduction of inorganic sulfur compounds by the fungus Fusarium oxysporum was examined. When transferred from a normoxic to an anoxic environment, F. oxysporum reduced elemental sulfur to hydrogen sulfide (H2S). This reaction accompanied fungal growth and oxidation of the carbon source (ethanol) to acetate. Over 2-fold more of H2S than of acetate was produced, which is the theoretical correlation for the oxidation of ethanol to acetate. NADH-dependent sulfur reductase (SR) activity was detected in cell-free extracts of the H2S-producing fungus, and was found to be up-regulated under the anaerobic conditions. On the other hands both O2 consumption by the cells and cytochrome c oxidase activity by the crude mitochondrial fractions decreased. These results indicate that H2S production involving SR was due to a novel dissimilation mechanism of F. oxysporum, and that the fungus adapts to anaerobic conditions by replacing the energy-producing mechanism of O2 respiration with sulfur reduction.
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  • Keitarou KIMURA, Yoshifumi ITOH
    2007 Volume 71 Issue 10 Pages 2458-2464
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
    JOURNALS FREE ACCESS
    The insertion sequence IS4Bsu1 frequently causes Bacillus subtilis starters for the production of Japanese fermented soybean pasts (natto) to lose the ability to produce poly-γ-glutamate, the viscous material characteristic of natto. Bacillus subtilis NAFM5, a derivative of a natto starter, has six IS4Bsu1 copies on its chromosome. In this study, we determined all six insertion loci of the insertion sequence (IS). One was located in the coding region of yktD, a putative gene involved in polyketide synthesis. Four were located in non-coding regions between iolR and iolA, between tuaA and lytC, between rapI and orf1 (a potential gene of unknown function), and between ynaE and orf3 (a putative gene similar to thiF), and one resided in an intergenic region between divergent possible orf4 and orf5 genes of unknown function. Here we describe the structural features of these loci and discuss the effects of the IS4Bsu1 insertions on the functions of the target gene and the expression of the downstream genes. In addition, we found that strain NAFM5 and commercial natto starters possess eight to 10 loci of another IS of the IS256 family (designated IS256Bsu1) on their chromosomes. IS256Bus1 appeared active in transposition, potentially causing phenotypic alterations in natto starters like those induced by IS4Bsu1.
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  • Taisuke WATANABE, Soichi FURUKAWA, Taketo KAWARAI, Masaaki WACHI, Hiro ...
    2007 Volume 71 Issue 10 Pages 2522-2526
    Published: October 23, 2007
    Released: October 23, 2007
    [Advance publication] Released: October 07, 2007
    JOURNALS FREE ACCESS
    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. Most DNA from the cells subjected to HCT was probably caught in the denatured protein layer during phenol extraction. The efficiency of DNA recovery from proteinase-treated crude extracts from cells subjected to HCT was high. Crude extracts of E. coli K12 cells that had not undergone HCT were intentionally acidified with acetic acid to pH 5.2 to cause acidic coagulation of cytoplasmic proteins. The efficiency of DNA recovery from the acidified extracts was low. These results suggest that in cells subjected to HCT, cytoplasmic pH is reduced to around pH 5.2, and that nuclear DNA becomes entangled in coagulated cytoplasmic proteins. Acidification of the cytoplasm might be the primary mechanism by which HCT inactivates bacteria.
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Microbiology & Fermentation Technology Notes
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