Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
Volume 70 , Issue 12
Showing 1-45 articles out of 45 articles from the selected issue
Analytical Chemistry Regular Paper
  • Hidetoshi MORITA, Hiroshi YOSHIKAWA, Tatsuya TAKIZAWA, Mitsuyuki SHIRA ...
    2006 Volume 70 Issue 12 Pages 2974-2981
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    Rat livers and microsomes were subjected to electron paramagnetic resonance (EPR) measurements at 77 K. The EPR spectra of the livers from the control group, carbon tetrachloride-, 3-methylcholanthrene-, and 3,3′,4,4′,5-pentachlorobiphenyl (PCB126)-treated rats exhibited an EPR spectrum at g=2.40, 2.24, and 1.93, which is characteristic of P450 in a resting state. The liver of the PCB126-treated rats showed an additional distinct EPR spectrum at g=2.49, 2.26, and 1.87 (g=2.49-species). The heme environmental structure of g=2.49-species was identified by crystal field analysis using three EPR g-values of the microsome treated with various chemicals. These results indicated that g=2.49-species is a hemeprotein with cysteine thiolate at the 5th coordination site, and a nitrogenous ligand at the 6th site.
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Analytical Chemistry Note
Organic Chemistry Regular Papers
  • Satoshi YAMAUCHI, Takuya SUGAHARA, Yuki NAKASHIMA, Koki ABE, Yoshimasa ...
    2006 Volume 70 Issue 12 Pages 2942-2947
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    The cytotoxic activity for colon 26 cell line of matairesinol, oxidized matairesinol, 9,9′-epoxylignan and oxidized 9,9′-epoxylignan were examined. (−)-Matairesinol (Mat 1) showed greatest cytotoxic activity (LC50=9 μg/ml) of the lactone-type lignans. 7,7′-Oxomatairesinol having same steric configuration as that of (−)-matairesinol showed greater activity (LC50=25 μg/ml) than hydroxy or mono-oxomatairesinol. The activities of 9,9′-epoxylignan and 7,7′-oxo-9,9′-epoxylignan having same steric configurations as (−)-matairesinol were weaker than that of corresponding matairesinols. Different activity levels were observed between enantiomers.
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  • Yusuke SAWAYAMA, Takashi TSUJIMOTO, Kumi SUGINO, Toshio NISHIKAWA, Min ...
    2006 Volume 70 Issue 12 Pages 2998-3003
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    Naturally occurring terphenyls and related compounds such as terferol and its corresponding quinone and phlebiarubrone were synthesized from 2,5-diphenyl-1,4-benzoquinone. According to the proposed biosynthetic pathway, chemical conversion of phlebiarubrone to ustalic acid, a toxic compound isolated from the poisonous mushroom, Tricholoma ustale, was examined to find a low-yield conversion to the ustalic acid dimethyl ester.
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Organic Chemistry Communication
  • Hiroya TAKADA, Ken KOKUBO, Kenji MATSUBAYASHI, Takumi OSHIMA
    2006 Volume 70 Issue 12 Pages 3088-3093
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    We investigated the antioxidant activity of supramolecular water-soluble fullerenes, polyvinylpyrrolidone (PVP)-entrapped C60, and γ-cyclodextrin (CD)-bicapped C60, based on comparable β-carotene bleaching assay. Antioxidant activity against reactive oxygen species (ROS) generated by three different methods, (i) autoxidation of linoleic acid, (ii) hydrogen peroxide promoter, and (iii) photoirradiation, was evaluated as percent of inhibition relative to a control experiment in view of the bleaching rate constant (kobs) as well as the persistent absorbancy of β-carotene. Water-soluble fullerenes exhibit significant inhibitory effects on the oxidative discoloration of β-carotene in any system.
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Biochemistry & Molecular Biology Regular Papers
  • Bun-ichiro ONO, Masashi KUBOTA, Hiroko KIMIDUKA, Hiroshi KAWAMINAMI, T ...
    2006 Volume 70 Issue 12 Pages 2813-2823
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    In the course of studying [PSI+], a yeast prion, we found inadvertently that Escherichia coli strain BL21 overproducing a fusion protein, in which the prion-domain of Sup35 was connected to the C terminus of glutathione S-transferase, grew normally to the stationary phase and rapidly decreased in colony-forming ability thereafter. Evidence indicated that protein polymers consisting mainly of the fusion protein GST-Sup35NM (about 70% of the mass) and its N-terminal fragments were formed in extract prepared from the cells producing GST-Sup35NM. It was further found that cells of strain BL21 accumulated the protein polymers during prolonged cultivation. Based on these results, we contend that the initially observed defect in colony forming ability is the direct or indirect consequence of intracellular formation and accumulation of the protein polymers.
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  • Tianqi WANG, Hanxiang LI, Kaili NIE, Tianwei TAN
    2006 Volume 70 Issue 12 Pages 2883-2888
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    A water-insoluble linear (1→3)-α-D-glucan was isolated from Penicillium mycelia. Three kinds of epoxy-activated microspheres of this glucan were prepared as supports for Candida sp. lipase (EC3.1.1.3) immobilization. The highest immobilization yield was 36.4%. The specific activity was 26.85 U/mg, and only 4.1% of activity was lost in comparison with the free enzyme used for immobilization. The higher thermal stability, storage stability, and reusability of the immobilized lipase make it a potential candidate for wide application.
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  • Jintanart WONGCHAWALIT, Takeshi YAMAMOTO, Hiroyuki NAKAI, Young-Min KI ...
    2006 Volume 70 Issue 12 Pages 2889-2898
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    α-Glucosidase (JHGase I) was purified from a Japanese subspecies of eastern honeybee (Apis cerana japonica) as an electrophoretically homogeneous protein. Enzyme activity of the crude extract was mainly separated into two fractions (component I and II) by salting-out chromatography. JHGase I was isolated from component I by further purification procedure using CM-Toyopearl 650M and Sephacryl S-100. JHGase I was a monomeric glycoprotein (containing 15% carbohydrate), of which the molecular weight was 82,000. Enzyme displayed the highest activity at pH 5.0, and was stable up to 40 °C and in a pH-range of 4.5–10.5. JHGase I showed unusual kinetic features: the negative cooperative behavior on the intrinsic reaction on cleavage of sucrose, maltose, and p-nitrophenyl α-glucoside, and the positive cooperative behavior on turanose. We isolated cDNA (1,930 bp) of JHGase I, of which the deduced amino-acid sequence (577 residues) confirmed that JHGase I was a member of α-amylase family enzymes. Western honeybees (Apis mellifera) had three α-glucosidase isoenzymes (WHGase I, II, and III), in which JHGase I was considered to correspond to WHGase I.
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  • Jun ASAMI, Hiroko ODANI, Aiko ISHII, Kayoko OIDE, Takako SUDO, Atsushi ...
    2006 Volume 70 Issue 12 Pages 2899-2905
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    Unilateral ureteral obstruction (UUO) of kidneys causes acute generation of carbonyl stress. By electrospray ionization/liquid chromatography/mass spectrometry (ESI/LC/MS) we measured the content of methyl glyoxal, glyoxal, and 3-deoxyglucosone in mouse kidney extracts following UUO. UUO resulted in elevation of these dicarbonyls in the obstructed kidneys. Furthermore, the accumulation of 3-deoxyglucosone was significantly reduced in the kidneys of mice transgenic for α-dicarbonyl/L-xylulose reductase (DCXR) as compared to their wild-type littermates, demonstrating 4.91±2.04 vs. 6.45±1.85 ng/mg protein (P=0.044) for the obstructed kidneys, and 3.68±1.95 vs. 5.20±1.39 ng/mg protein (P=0.026) for the contralateral kidneys. On the other hand, collagen III content in kidneys showed no difference as monitored by in situ hybridization. Collectively, DCXR may function in the removal of renal α-dicarbonyl compounds under oxidative circumstances, but it was not sufficient to suppress acute renal fibrosis during 7 d of UUO by itself.
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  • Yoshiya GUNJI, Hisao ITO, Haruhiko MASAKI, Hisashi YASUEDA
    2006 Volume 70 Issue 12 Pages 2927-2934
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    lysE24 is an allele of lysE encoding an L-lysine exporter of Corynebacterium glutamicum. The mutant gene is able to induce L-lysine production in Methylophilus methylotrophus. Although lysE24 has a mutation in the middle of lysE that results in chain termination, the entire lysE locus, including the region downstream of the short open reading frame, is necessary for L-lysine production. We propose that separate polypeptides are synthesized from the lysE24 locus due to reinitiation of translation utilizing an existing start codon beyond the site of the frameshift, and present evidence that translational coupling is required to form the functional lysE24 product. In addition, expression of lysE24 induces L-lysine production in another methylotroph, Methylobacillus glycogenes. These data suggest that the lysE24 product is a split protein and that this curious feature might be a structure necessary for its functioning in certain obligate gram-negative methylotrophs.
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  • Hiroyuki SAITOH, Shiro OKUMURA, Tomoyuki ISHIKAWA, Tetsuyuki AKAO, Eii ...
    2006 Volume 70 Issue 12 Pages 2935-2941
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    A novel gene encoding a leukemic cell-killing parasporal protein, designated parasporin-4, was cloned from an isolate of Bacillus thuringiensis serovar shandongiensis. The amino acid sequence of the parasporin-4, as deduced from the gene sequence, had low-level homologies of <30% with the established B. thuringiensis Cry proteins including the three known parasporins. When the gene was expressed in a recombinant of Escherichia coli BL21(DE3), the parasporin-4 formed intracellular inclusion bodies. Alkali-solubilized and proteinase K-activated inclusion protein exhibited strong cytotoxic activity against human leukemic T cells (MOLT-4) and weak for normal T cells, but no adverse effect on human uterus cervix cancer cells (HeLa).
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  • Hikaru WATANABE, Rohko TAKAKURA-YAMAMOTO, Mayumi KUROSE, Kenshi YOSHID ...
    2006 Volume 70 Issue 12 Pages 3013-3018
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    Production of a novel cyclomaltopentaose cyclized by an α-1,6-linkage, [ICG5; cyclo-{→6)-α-D-Glcp-(1→4)-α-D-Glcp-(1→4)-α-D-Glcp-(1→4)-α-D-Glcp-(1→4)-α-D-Glcp-(1→}], from starch was performed using isocyclomaltooligosaccharide glucanotransferase (IGTase) derived from Bacillus circulans AM7. The optimal conditions for ICG5-production from partially hydrolyzed starch were as follows: substrate concentration, 1.0% (w/v); pH, 5.5; temperature, 45 °C; reaction time, 24 h, IGTase, 1.0 unit/g-dry solid (DS); isoamylase, 2,500 units/g-DS. The yield of ICG5 reached 25.9% under optimal conditions. ICG5-production was achieved from partially hydrolyzed starch using a crude enzyme preparation containing IGTase. Finally, ICG5 was obtained in a yield of 17.9% (99.3% purity, 2,681 g-DS). A digestive test with a human salivary amylase, an artificial gastric juice, a pancreatic amylase, and small intestinal enzymes showed that ICG5 was an indigestible oligosaccharide.
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Biochemistry & Molecular Biology Notes
Biochemistry & Molecular Communications
  • Tsuyoshi KAWANO, Ryosuke NAGATOMO, Yasuo KIMURA, Keiko GENGYO-ANDO, Sh ...
    2006 Volume 70 Issue 12 Pages 3084-3087
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    The insulin/insulin-like growth factor-I signaling (IIS) pathway regulates larval diapause, adult lifespan, fat metabolism, and stress-resistance in the nematode Caenorhabditis elegans. One of 38 C. elegans insulin-like genes, ins-11, was disrupted and phenotypic analyses of the gene-disrupted animal were performed. The gene-disruption exhibited a significant influence on the adult lifespan. It antagonized the lifespan extension induced by RNAi knockdown of another insulin-like gene, ins-7. Hence ins-11 appears to be necessary for lifespan extension caused by a decrease in the IIS pathway. This is the first description of gene-disruption of the C. elegans insulin-like gene that suppresses the lifespan extension.
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  • Shinji NAGATA, Yukie OMORI, Hiromichi NAGASAWA
    2006 Volume 70 Issue 12 Pages 3094-3098
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    Since insects are unable to biosynthesize sterols de novo, sterols must be obtained from dietary sources. Although it has been reported that β-sitosterol is crucial for larval growth in the silkworm, Bombyx mori, little has been investigated concerning the dietary selection of sterols by Bombyx larvae. Here, we demonstrate that Bombyx larvae have the following sterol preference: β-sitosterol >> ergosterol > cholesterol = stigmasterol. Interestingly, Bombyx larvae preferred ergosterol, an inhibitory sterol on larval growth, indicating that sterol selection following first contact of the diet with the mouthpart might be different from the sterol recognition mechanism present in sterol metabolism.
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Food & Nutrition Science Regular Papers
  • Fuminori KAWABATA, Naohiko INOUE, Susumu YAZAWA, Teruo KAWADA, Kazuo I ...
    2006 Volume 70 Issue 12 Pages 2824-2835
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    ‘CH-19 Sweet’ is a non-pungent red pepper and enhances the energy expenditure in humans in like manner to the pungent red pepper. We investigated in this study the effects of a repeated intake of CH-19 Sweet for two weeks on the body weight and body fat in humans. Changes in the autonomic nervous activity after ingesting CH-19 Sweet were also measured by a power spectral analysis. We established a new protocol which allows the precise detection of weight change in humans by using fewer subjects. These methods were used to show that the repeated intake of CH-19 Sweet reduced the body weight and suppressed body fat accumulation. Furthermore, the body weight loss due to the repeated intake of CH-19 Sweet was significantly correlated with the sympathetic nervous response after its ingestion. We propose that the repeated intake of CH-19 Sweet reduced the body weight and suppressed body fat accumulation by sympathetic nervous activation in humans.
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  • Eiichiro ONITSUKA, Tomoyuki OKUMURA, Hiroshi MURAKAMI, Norikazu NISHIN ...
    2006 Volume 70 Issue 12 Pages 2836-2843
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    We attempted to develop a method to determine easily and effectively the degree of postmortem aging of pork longissimus dorsi (LD) by measuring the activity of proteases in the LD using fluorogenic peptide substrates. LD was used to measure the change with time in the protease activity detected with these substrates. Determining the variations within the LD muscles, strong positive correlations were found between changes in hardness and fluorescence intensities against Ac-Ala-MCA, Ac-Met-MCA, Ac-Ser-MCA, Ac-Thr-MCA, and Ac-Ala-Phe-MCA (P<0.005), and strong negative correlations were found between changes in total amounts of free amino acids and Ac-Ala-MCA, Ac-Met-MCA, Ac-Ser-MCA, Ac-Thr-MCA, and Ac-Ala-Phe-MCA (P<0.001). Negative correlations were also observed between changes in the amounts of free Ala, Arg, Lys, Leu, Met, Phe, and Tyr and the fluorescence intensities against Ala, Arg, Lys, Leu, Met, Phe, and Tyr-MCA respectively (P<0.001).
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  • Noriko HIGAKI, Kenji SATO, Hitoshi SUDA, Tomohiko SUZUKA, Takeo KOMORI ...
    2006 Volume 70 Issue 12 Pages 2844-2852
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    Feeding HMF, an insoluble “high-molecular-weight fraction” from an industrial enzymatic digest of a soy protein isolate, increased the fecal excretion of bile acid concomitant with increased fecal nitrogen. An amino acid analysis revealed that this increased fecal nitrogen could be explained by an increase in the insoluble protein fraction. This suggests the existence of an indigestable protein or peptide that can be called a “resistant protein” in the feces. The presumed resistant protein was rich in hydrophobic amino acids and bound bile acid by hydrophobic interaction. The residual fraction of HMF obtained after in vitro pepsin and pancreatin digestion, showed higher in vitro bile acid-binding capacity and excreted more bile acid in vivo than HMF. Its amino acid composition was similar to that of the feces of rat fed with HMF. These results suggest that the fecal resistant protein with bile acid-binding ability could be derived from the indigestable fraction of HMF.
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  • Kenji HIKOSAKA, Yukari KOYAMA, Maki MOTOBU, Manabu YAMADA, Kikuyasu NA ...
    2006 Volume 70 Issue 12 Pages 2853-2858
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    A sugar cane extract (SCE) has been found to have an immunostimulating effect in several animals. Lipopolysaccharide (LPS) is known to induce endotoxin shock via the production of inflammatory modulators such as tumor necrosis factor (TNF)-α and nitric oxide (NO). We examined in the present study the effects of SCE on the TNF-α and NO production in LPS-stimulated mice peritoneal cells and the endotoxin shock in mice. The supplementation of SCE to peritoneal macrophages cultured with LPS resulted in a significant decrease in NO production. All the mice injected intraperitoneally with LPS and D-galactosamine (LPS+GalN) died within 24 h. However, a peritoneal injection, but no intravenous or oral administration, of SCE (500–1,000 mg/kg) at 3 to 48 h before the LPS+GalN-challenge resulted in a significantly improved survival rate. These results suggest that SCE had a protective effect on LPS-induced endotoxin shock via one of possible mechanisms involving the suppression of NO production in the mouse peritoneal cavity.
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  • Yuanxia SUN, Shigeru HAYAKAWA, Huihong JIANG, Masahiro OGAWA, Ken IZUM ...
    2006 Volume 70 Issue 12 Pages 2859-2867
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    Custard pudding gels were prepared from fresh whole egg, milk and sugar. The effects of D-psicose (Psi), a non-calorie rare hexose, on the antioxidative activity and rheological properties of the custard pudding gels were investigated at different temperatures for comparison with those of control sugars (sucrose, Suc; D-fructose, Fru). The rheological behavior of the heat-induced pudding gels was evaluated by using breaking and creep tests. During the heat-induced gel formation, custard pudding containing Psi (15%, wt/wt) demonstrated a stronger breaking strength and higher viscoelasticity than those containing Fru and Suc. The thermodynamic parameters obtained from DSC indicated that the egg white (EW) proteins were made less thermally stable when heated in the presence of Psi than in the presence of Fru and Suc. These findings are consistent with enhanced aggregation of the EW solution in the presence of Psi. Furthermore, the Psi pudding gels possessed higher antioxidative activity than the control sugar pudding gels by using an analysis of the scavenging activity on DPPH radicals and the ferric-reducing antioxidative power. These results suggest that Psi favored cross-linking of Psi-protein molecules through the Maillard reaction which increased the formation of intermediate products to improve functionality. Custard pudding containing Psi could therefore be an effective functional sweet dessert with high antioxidative activity and the outstanding gelling characteristics.
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  • Kyoka TAKASHIMA-SASAKI, Masatoshi KOMIYAMA, Tetsuya ADACHI, Kenichi SA ...
    2006 Volume 70 Issue 12 Pages 2874-2882
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    Isoflavone (IF), a type of phytoestrogen, has multiple beneficial effects, but too much phytoestrogen can have adverse effects on offspring. To examine whether chronic exposure to high IF has adverse effects on reproductive development, mice offspring were exposed to IF through dietary administration to dams during pregnancy and lactation and to the offspring directly after weaning until sacrifice. In male offspring, there was no difference between the IF group and controls; however, in female offspring in the IF group, remarkably earlier puberty and induction of multioocyte follicles on postnatal day (PND) 21 were observed. Gene expression levels of estrogen receptor β decreased in the ovary and vagina on PND 21. These results suggest that chronic exposure to higher than normal levels of IF induces alterations in the reproductive development of female mice through an estrogenic effect.
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  • Tatsuya SUGAWARA, Nobuhiro ZAIMA, Akiyo YAMAMOTO, Shota SAKAI, Ryoko N ...
    2006 Volume 70 Issue 12 Pages 2906-2912
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    Sea cucumber is a health-beneficial food, and contains a variety of physiologically active substances including glycosphingolipids. We show here the sphingoid base composition of cerebrosides prepared from sea cucumber and the cytotoxicity against human colon cancer cell lines. The composition of sphingoid bases prepared from sea cucumber was different from that of mammals, and the major constituents estimated from mass spectra had a branched C17–19 alkyl chain with 1–3 double bonds. The viability of DLD-1, WiDr and Caco-2 cells treated with sea cucumber sphingoid bases was reduced in a dose-dependent manner and was similar to that of cells treated with sphingosine. The sphingoid bases induced such a morphological change as condensed chromatin fragments and increased the caspase-3 activity, indicating that the sphingoid bases reduced the cell viability by causing apoptosis in these cells. Sphingolipids of sea cucumber might therefore serve as bioactive dietary components to suppress colon cancer.
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  • Saori TAKAHASHI, Hironobu OGASAWARA, Takayuki WATANABE, Masanori KUMAG ...
    2006 Volume 70 Issue 12 Pages 2913-2918
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    Human prorenin was expressed in Escherichia coli as a fusion protein of thioredoxin. The chimeric protein, which accumulated insoluble inclusion bodies, was solubilized in 4 M guanidine–HCl and refolded by an arginine-detergent buffer system and by systematic dialysis. The refolded fusion prorenin was activated by trypsin. The antiserum against human kidney renin specifically inhibited the recombinant human renin activity. Using the recombinant human renin, we screened its inhibitory activity in fermented soybean paste (miso) and demonstrated that miso contained renin inhibitory activity derived from soybean. The IC50 values for soybean and steamed soybean extracts were determined to be 1.9 and 1.6 mg/ml, respectively. This is the first demonstration of renin inhibitory activity in miso and soybean.
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  • Hisami SHINOHARA, Jian WU, Michio KASAI, Toshiaki AOYAMA
    2006 Volume 70 Issue 12 Pages 2919-2926
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    We have reported previously that randomly interesterified triacylglycerol containing medium- and long-chain fatty acids in the same glycerol molecule (MLCT) resulted in significantly lower body fat accumulation and higher hepatic fatty acid oxidation than from long-chain triacylglycerol (LCT) in rats. To understand the metabolic changes occurring in white adipose tissue, the fatty acid oxidation and synthesis, and the adipocytokine level were measured in rats fed with MLCT or LCT for 2 weeks. In comparison with LCT, MLCT lowered not only the fatty acid synthase and glycerol-3-phosphate dehydrogenase activities in perirenal adipose tissue, but also the serum insulin and leptin levels, in addition to significantly reducing the body fat accumulation. In contrast, fatty acid oxidation measured as the carnitine palmitoyltransferase activity in the tissue was significantly higher in the MLCT-fed rats than in the LCT-fed rats. It seems that the altered fatty acid metabolism in adipose tissue per se was also responsible for the lower adiposity by dietary MLCT.
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  • Tong CUI, Kozo NAKAMURA, Su TIAN, Hiroshi KAYAHARA, Yi-Ling TIAN
    2006 Volume 70 Issue 12 Pages 2948-2956
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    Hawthorn polyphenol (HP) was prepared by ethyl acetate treatment of the ethanol extract (HE) of Chinese hawthorn fruit. The concentrations of 15 polyphenols in the HP, HE, extraction residue (HJ), and a hawthorn leaf extract (HF) were determined by HPLC. For HP, the total content of the 15 polyphenols was 21.4%, comprised of 19.7% of procyanidins, 1.21% of chlorogenic acid, and 0.48% of flavonoids, compared to 2.55% for the HE. The yields of procyanidin monomer, dimer, trimer, tetramer, and pentamer were 50.5%, 30.3%, 23.0%, 14.6%, and 12.5% respectively, and the mean degree of polymerization was reduced to 1.39 (HP) from 1.65 (HE). Seven different physiological actions of the four extracts were investigated. The HP showed strong O2 and OH scavenging capacities (IC50 values of 6.3 μg/ml and 1.1 μg/ml respectively), as well as selective prolyl endopeptidase inhibition (IC50 of 60 μg/ml). The active constituents appeared to be procyanidins.
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  • Akie TOYOTA, Hiroshi AKIYAMA, Mitsunori SUGIMURA, Takahiro WATANABE, K ...
    2006 Volume 70 Issue 12 Pages 2965-2973
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    For rough quantitative analysis of genetically modified maize contents, rapid methods for measurement of the copy numbers of the cauliflower mosaic virus 35S promoter region (P35S) and MON810 construct-specific gene (MON810) using a combination of a capillary-type real-time PCR system with a plasmid DNA were established. To reduce the characteristic differences between the plasmid DNA and genomic DNA, we showed that pretreatment of the extracted genomic DNA by a combination of sonication and restriction endonuclease digestion before measurement is effective. The accuracy and reproducibility of this method for MON810 content (%) at a level of 5.0% MON810 mixed samples were within a range from 4.26 to 5.11% in the P35S copy number quantification. These methods should prove to be a useful tool to roughly quantify GM maize content.
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  • Hanae IZU, Megumi SHOBAYASHI, Yasuko MANABE, Kuniyasu GOTO, Haruyuki I ...
    2006 Volume 70 Issue 12 Pages 2982-2989
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    The suppressive effects on acute alcoholic liver injury of S-adenosylmethionine (SAM) and the sake yeast, Saccharomyces cerevisiae Kyokai No. 9, have been shown previously. To enhance the suppression of acute alcoholic liver injury by sake yeast, we prepared SAM-accumulating sake yeast (SAM yeast). Male C57BL/6 mice that had been fed on a diet containing 0.25% SAM yeast or sake yeast for two weeks received three doses of ethanol (5 g/kg BW). In the mice fed on the SAM yeast, the ethanol-induced increases in both triglyceride (TG) and alanine aminotransferase (ALT) were significantly repressed. In addition, the SAM yeast-fed mice did not show an ethanol-induced decrease in hepatic SAM level, suggesting that a disorder of methionine metabolism in the liver caused by ethanol was relieved by the SAM yeast. These results suggest that the SAM yeast had a stronger effect suppressing acute alcoholic liver injury in mice than the sake yeast.
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  • Shuichi SEGAWA, Kazuhisa YASUI, Yoshihiro TAKATA, Toshio KURIHARA, Hir ...
    2006 Volume 70 Issue 12 Pages 2990-2997
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
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    The antiallergic properties of hop water extract (HWE) were studied by evaluating histamine release from human basophilic KU812 cells induced by calcium ionophore A23187. HWE significantly inhibited histamine release, but boiling water extract and chloroform–methanol extract did not show any inhibitory effect on it. A 50% methanol-eluted fraction separated from HWE by XAD-4 column chromatography (MFH) had a strong inhibitory effect as compared with HWE. Quercetin glycosides and kaempherol glycosides were identified in MFH, of which quercetin glycosides contributed to the inhibition of histamine release. Most quercetin in HWE existed in glycoside form and its quercetin content, obtained by acid hydrolysis, was about 200 μg/g. HWE and MFH significantly inhibited protein kinase C, which plays a pivotal role in the degranulation of chemical mediators. These results indicate that HWE can inhibit type-I allergic reactions.
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Food & Nutrition Science Notes
Microbiology & Fermentation Technology Regular Papers
  • Makiko SAKKA, Tetsuya KIMURA, Kazuo SAKKA
    2006 Volume 70 Issue 12 Pages 2868-2873
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
    JOURNALS FREE ACCESS
    Refuse-derived fuels (RDF) pellets manufactured in Japan have been reported to contain a relatively high number of viable bacterial cells, and these bacteria generated a large amount of hydrogen gas during fermentation under wet conditions. In this study, we compared hydrogen gas generation from RDF pellets manufactured in Japan and in Germany and found that a large amount of hydrogen gas was generated from the Japanese RDF pellets but not from the German ones. This difference can be explained by the absence and presence of a biodegradation process before molding of raw garbage into RDF pellets. That is, the German process includes a biodegradation (or biological drying) process with forced aeration for a week, and this appears to reduce BOD in the garbage. Denaturing gradient gel electrophoresis analysis of 16S rRNA gene followed by DNA sequencing indicated that microbiotas of the RDF pellets manufactured in Japan and in Germany were very different.
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  • Ken-ichi YOSHIDA, Won-Seok KIM, Masaki KINEHARA, Rie MUKAI, Hitoshi AS ...
    2006 Volume 70 Issue 12 Pages 2957-2964
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
    JOURNALS FREE ACCESS
    Sinorhizobium fredii USDA191 is a Gram-negative bacterium capable of forming nitrogen-fixing nodules on soybean roots. The USDA191 idhA gene encoding myo-inositol dehydrogenase, an enzyme necessary for myo-inositol utilization, is known to be involved in competitive nodulation and nitrogen fixation. In Bacillus subtilis, myo-inositol dehydrogenase catalyzes the first step of the myo-inositol catabolic pathway. Recently iolE was identified as the gene encoding 2-keto-myo-inositol dehydratase, which catalyzes the second step in the pathway. Here we report the presence of 2-keto-myo-inositol dehydratase activity in free-living USDA191 cells cultured in a medium containing myo-inositol. An iolE ortholog was cloned from USDA191. USDA191 iolE was expressed in Escherichia coli as a His6-tag fusion and purified to exhibit 2-keto-myo-inositol dehydratase activity. Inactivation of USDA191 iolE led to defective myo-inositol utilization. USDA191 iolE partially complemented a B. subtilis iolE deficient mutant. These results suggest that S. fredii USDA191 utilizes a myo-inositol catabolic pathway, analogous to that of B. subtilis, involving at least idhA and iolE.
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  • Katsumi AMAKO, Kazuyo FUJITA, Chiaki IWAMOTO, Myagmarsuren SENGEE, Kaz ...
    2006 Volume 70 Issue 12 Pages 3004-3012
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
    JOURNALS FREE ACCESS
    The molecular aspects and physiological significance of NADP+-dependent D-arabinose dehydrogenase (ARA), which is thought to function in the biosynthesis of an analog of ascorbic acid, D-erythroascorbic acid in yeasts, were examined. A large subunit of ARA, Ara1p produced in E. coli, was purified as a homodimer, some of which was degraded at the N-terminus. It showed sufficient ARA activity. Degradation of Ara1p occurs naturally in yeast cells, and the small subunit of ARA previously thought as is, in fact, a naturally occuring degradation product of Ara1p. A deficient mutant of ARA1 lost almost all NADP+-ARA activity, but intracellular D-erythroascorbic acid was only halved. This mutant showed increased susceptibility to H2O2 and diamide but not to menadione or tert-butylhydroperoxide. Feeding D-arabinose to mutant cells led to increases in intracellular D-erythroascorbic acid, suggesting the presence of another ARA isozyme. The deficient mutant of ARA1 recovered resistance to H2O2 with feeding of D-arabinose. Our results suggest that the direct contributions of Ara1p both to D-erythroascorbic acid biosynthesis and to oxidative stress resistance are quite limited.
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  • Akiko TAKEUCHI, Akiko SHIMIZU-IBUKA, Yoshitaka NISHIYAMA, Kiyoshi MURA ...
    2006 Volume 70 Issue 12 Pages 3019-3024
    Published: December 23, 2006
    Released: December 23, 2006
    [Advance publication] Released: December 07, 2006
    JOURNALS FREE ACCESS
    Among more than 20 yeast strains isolated from the traditional starter “murcha” in Nepal, we characterized a yeast that might be involved in saccharification. This strain, identified as Pichia burtonii, produced an extracellular amylolytic enzyme when cultured in the presence of starch in the medium. Since no amylase secreted by P. burtonii has yet been reported, we purified the enzyme and determined its N-terminal amino acid sequence. Together with the results of a hydrolyzing activity assay toward various substrates, it was found to be an α-amylase. The purified enzyme, named Pichia burtonii α-amylase (PBA), was a glycoprotein with an apparent molecular mass of 51 kDa. Enzyme activity was optimal at pH 5.0 at 40 °C. The enzyme retained 80% of its original activity after incubation under the optimal pH condition at 50 °C for 30 min. The activity was inhibited by metal ions such as Cd2+, Cu2+, Hg2+, Al3+, and Zn2+.
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Microbiology & Fermentation Technology Notes
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