Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
Volume 75 , Issue 9
Showing 1-43 articles out of 43 articles from the selected issue
Organic Chemistry Regular Papers
  • Zhi-Yu NI, Yi-Bing WU, Man-Li ZHANG, Yu-Fang WANG, Mei DONG, Fran&cced ...
    2011 Volume 75 Issue 9 Pages 1698-1701
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
    JOURNALS FREE ACCESS
    A novel 6/8/6-membered taxane with a rare C-12(13)-double bond and rare 2(3→20)abeotaxane were isolated from the needles of Taxus canadensis. Their structures were characterized as 7β,9α,10β-triacetoxytaxa-4(20),12-diene-2α,5α,11β-triol (1) and 2α,7β,10β-triacetoxy-5α-hydroxy-2(3→20)abeotaxa-4(20),11-diene-9,13-dione (2) on the basis of 1D and 2D spectroscopic data. 1 is the first example of a natural taxane without substitution at both C-13 and C-14.
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  • Makoto HASHIMOTO, Hirotaka KATSURA, Risako KATO, Hiroshi KAWAIDE, Masa ...
    2011 Volume 75 Issue 9 Pages 1722-1726
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
    JOURNALS FREE ACCESS
    Supplementary material
    The effect of the aerial mycelium-inducing compound, pamamycin-607, on antibiotic production by several Streptomyces spp. was examined. Exposure to 6.6 μM pamamycin-607 stimulated by 2.7 fold the puromycin production by Streptomyces alboniger NBRC 12738, in which pamamycin-607 had first been isolated, and restored aerial mycelium formation. Pamamycin-607 also stimulated the respective production of streptomycin by S. griseus NBRC 12875 and that of cinerubins A and B by S. tauricus JCM 4837 by approximately 1.5, 1.7 and 1.9 fold. The antibiotic produced by Streptomyces sp. 91-a was identified as virginiamycin M1, and its synthesis was enhanced 2.6 fold by pamamycin-607. These results demonstrate that pamamycin-607 not only restored or stimulated aerial mycelium formation, but also stimulated secondary metabolite production.
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  • Hisashi NISHIWAKI, Ayaka HASEBE, Yuya KAWAGUCHI, Miki AKAMATSU, Yoshih ...
    2011 Volume 75 Issue 9 Pages 1735-1739
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
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    The larvicidal activity against Culex pipiens of all stereoisomers of dihydroguaiaretic acid (DGA) and secoisolariciresinol was measured, and these DGAs were found to be potent. Sixteen (−)-DGA derivatives were then newly synthesized to analyze their structure-activity relationship. Two derivatives monohydroxylated at the 3- or 4-position of the 7-phenyl group of DGA induced acute paralytic activity in the mosquitoes. Derivatives with several hydroxyl groups had lower activity than the natural compound, suggesting that hydrophobicity was probably an important factor for their insecticidal activity.
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  • Ryuya FUJII, Atsushi MINAMI, Tae TSUKAGOSHI, Natsuko SATO, Takehiko SA ...
    2011 Volume 75 Issue 9 Pages 1813-1817
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
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    Supplementary material
    Clustering of biosynthetic genes for producing fungal secondary metabolites, which frequently consist of less than ten genes, has been recognized with numerous genomes. The heterologous expression of whole genes in the clusters will therefore produce various types of natural products when using a suitable fungal host. We introduced the whole gene cluster for the biosynthesis of diterpene aphidicolin into the fungal quadruple auxotrophic host, Aspergillus oryzae, by using four different vectors (pTAex3, pPTRI, pUSA and pAdeA) which harbor a starch-inducible promoter/terminator to examine the expression conditions. The resulting quadruple transformant carrying the genes of geranylgeranyl diphosphate synthase PbGGS, terpene synthase PbACS, and two monooxygenases (PbP450-1 and PbP450-2) produced aphidicolin. The double and triple transformants also respectively produced aphidicolan-16β-ol and 3-deoxyaphidicolin. Alternative host Saccharomyces cerevisiae carrying the genes, PbGGS and PbACS, produced key intermediate aphidicolan-16β-ol. This is the first example of a total biosynthesis of terpenoids using fungal hosts.
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  • Tuan T. NGUYEN, Kenji KANAORI, Masaru K. HOJO, Tatsuro KAWADA, Ryohei ...
    2011 Volume 75 Issue 9 Pages 1818-1822
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
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    We identified the soldier-specific compounds in the Japanese subterranean termite, Reticulitermes speratus, to clarify their ethological roles. Silica gel column chromatography separated one major soldier-specific compound in the hexane fraction accounting for 70–80% of the total amount of the fraction, while cuticular hydrocarbons constituted the rest. We identified the compound as β-selinene by gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) spectroscopy. Comparative GC analyses of the major exocrine glands detected the compound in the soldier’s frontal gland. Both soldiers and workers made aggregation to the hexane fraction, as well as to the crushed heads and head extract of the soldiers. They did not aggregate to cuticular hydrocarbons, making it likely that β-selinene was the aggregation pheromone in this species. The opportunistic predator of this termite, Lasius japonicus, was also attracted to the compounds. The ant workers, therefore, would use the termite aggregation pheromone as a kairomone for hunting them.
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Biochemistry & Molecular Biology Regular Papers
  • Daiju DOUBAYASHI, Takumi OOTAKE, Yosifumi MAEDA, Masaya OKI, Yuji TOKU ...
    2011 Volume 75 Issue 9 Pages 1662-1667
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
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    Formate oxidase of Aspergillus oryzae RIB40 contains an 8-replaced FAD with molecular mass of 799 as cofactor. The 1H-NMR spectrum of the cofactor fraction obtained from the enzyme indicated that the 8-replaced FAD in the fraction was 8-formyl-FAD, present in open form and hemiacetal form. The oxidation-reduction potentials of the open and hemiacetal forms were estimated by cyclic voltammetry to be −47 and −177 mV vs. Normal Hydrogen Electrode respectively. The structure of the enzyme was constructed using diffraction data to 2.24 Å resolution collected from a crystal of the enzyme. His511 and Arg554 were situated close to the pyrimidine part of the isoalloxazine ring of 8-formyl-FAD in open form. The enzyme had 8-formyl-FAD, the oxidation potential of which was approximately 160 mV more positive than that of FAD, and the His-Arg pair at the catalytic site, unlike the other enzymes belonging to the glucose-methanol-choline oxidoreductase family.
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  • Xia JIANG, Qian REN, Shi-Ping CHEN, Xiao-Bo TONG, Mei DONG, Shigeru SU ...
    2011 Volume 75 Issue 9 Pages 1685-1691
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
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    Little is known about the ability of miso, to modulate mutability in human cells. We have observed increased levels of glucose-regulated protein 78 (GRP78) expression in association with suppression of mutation in human RSa cells irradiated with ultraviolet C (UVC). Here we examined to determine whether miso treatment results in increased GRP78 expression and suppression of UVC mutagenicity in RSa cells. Supernatants of water extracts of miso products and their components were tested. In the sample-treated cells, the amount of GRP78, as estimated by RT-PCR and immunoblotting analysis, increased, and the UVC-induced ouabain resistant mutation (OuaR) and the K-ras codon 12-base substitution mutation frequency decreased. This decrease was not observed in cells with downregulation of GRP78 by GRP78 siRNA transfection. The results suggest that miso suppresses UVC mutagenicity by increasing GRP78 expression in human cells.
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  • Akihiko KIHARA, Wataru SABURI, Shinji WAKUTA, Myung-Hee KIM, Shigeki H ...
    2011 Volume 75 Issue 9 Pages 1740-1745
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
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    Nucleoside diphosphate kinase (NDPK) is a ubiquitous enzyme that catalyzes the transfer of the γ-phosphoryl group from a nucleoside triphosphate to a nucleoside diphosphate. In this study, we examined the subcellular localization, tissue-specific gene expression, and enzymatic characteristics of three rice NDPK isozymes (OsNDPK1-OsNDPK3). Sequence comparison of the three OsNDPKs suggested differential subcellular localization. Transient expression of green fluorescence protein-fused proteins in onion cells indicated that OsNDPK2 and OsNDPK3 are localized to plastid and mitochondria respectively, while OsNDPK1 is localized to the cytosol. Expression analysis indicated that all the OsNDPKs are expressed in the leaf, leaf sheath, and immature seeds, except for OsNDPK1, in the leaf sheath. Recombinant OsNDPK2 and OsNDPK3 showed lower optimum pH and higher stability under acidic pH than OsNDPK1. In ATP formation, all the OsNDPKs displayed lower Km values for the second substrate, ADP, than for the first substrate, NTP, and showed lowest and highest Km values for GTP and CTP respectively.
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  • Sanjenbam Kunjeshwori DEVI, Senjam Sunil SINGH, Sorokhaibam Jibankumar ...
    2011 Volume 75 Issue 9 Pages 1752-1757
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
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    A new magnesium ion requiring N-acetyl-D-glucosamine specific lectin QIL was purified to electrophoretic homogeneity from seeds of Quercus ilex L. through successive steps of (i) lectin extraction, (ii) ammonium sulphate (30–50%) fractionation, (iii) diethylaminoethyl (DEAE)-cellulose chromatography, (iv) carboxymethyl (CM)-cellulose chromatography, and (v) Sephadex G-75 chromatography. The lectin, having specific activity of 25,600 hemagglutination units (HAU)/mg of protein, was found to be a monomeric protein with a native molecular weight of 13.2 kDa. N-Acetyl-D-glucosamine was found to exhibit most potent inhibitory action on the lectin activity among all the sugars tested. The lectin was also found to exhibit specificity for human blood groups A, B, and AB. It was converted to the corresponding apo-lectin by ethylenediaminetetraacetic acid (EDTA) treatment followed by buffer dialysis. The apo-lectin exhibited a specific and characteristic requirement for magnesium ions for the expression of its activity.
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  • Dai-ichiro KATO, Keisuke YOKOYAMA, Yoshihiro HIRAISHI, Masahiro TAKEO, ...
    2011 Volume 75 Issue 9 Pages 1758-1762
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
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    Measurement of thioesterification activities for dodecanoic acid (C12) and ketoprofen was done using five firefly luciferases, from Pyrocoelia miyako (PmL), Photinus pyralis (PpL), Luciola cruciata (LcL), Hotaria parvura (HpL), and Luciola mingrelica (LmL). Among these, PmL, PpL, and LcL showed the expected thioesterification activities toward both substrates. All the enzymes exhibited (R)-enantioselectivity toward ketoprofen, which had same tendency as firefly luciferase from Luciola lateralis (LUC-H). HpL and LmL, however, did not accept ketoprofen, although they had thioesterification activity toward C12. These results indicate that the substrate acceptance of luciferases for the thioesterification reaction varies dramatically relying on the origin of firefly. Hence we focused primarily on PmL and investigated the effect of pH on enzymatic activity. In addition, by determining the kinetic parameters at various pH values, we verified that the kcat parameter contributed to the preferential enantioselectivity of this enzyme.
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  • Tamo FUKAMIZO, Hirokazu SATO, Mamiko MIZUHARA, Takayuki OHNUMA, Takesh ...
    2011 Volume 75 Issue 9 Pages 1763-1769
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
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    Autographa californica multiple nucleopolyhedrovirus (AcMNPV) chitinase is involved in the final liquefaction of infected host larvae. We purified the chitinase rapidly to homogeneity from Sf-9 cells infected with AcMNPV by a simple procedure using a pepstatin-aminohexyl-Sepharose column. In past studies, a recombinant AcMNPV chitinase was found to exhibit both exo- and endo-chitinase activities by analysis using artificial substrates with a fluorescent probe. In this study, however, we obtained more accurate information on the mode of action of the chitinase by HPLC analysis of the enzymatic products using natural oligosaccharide and polysaccharide substrates. The AcMNPV chitinase hydrolyzed the second β-1,4 glycosidic linkage from the non-reducing end of the chitin oligosaccharide substrates [(GlcNAc)n, n=4, 5, and 6], producing the β-anomer of (GlcNAc)2. The mode of action was similar to that of Serratia marcescens chitinase A (SmChiA), the amino acid sequence of which is 60.5% homologous to that of the AcMNPV enzyme. The enzyme also hydrolyzed solid β-chitin, producing only (GlcNAc)2. The AcMNPV chitinase processively hydrolyzes solid β-chitin in a manner similar to SmChiA. The processive mechanism of the enzyme appears to be advantageous in liquefaction of infected host larvae.
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  • Motohiro NISHIMURA, Kunie KOHNO, Yoshio NISHIMURA, Masanori INAGAKI, J ...
    2011 Volume 75 Issue 9 Pages 1770-1777
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
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    We purified two isozymes of coniferyl alcohol dehydrogenase (CADH I and II) to homogeneity from cell-free extracts of Streptomyces sp. NL15-2K. The apparent molecular masses of CADH I and II were determined to be 143 kDa and 151 kDa respectively by gel filtration, whereas their subunit molecular masses were determined to be 35,782.2 Da and 37,597.7 Da respectively by matrix-assisted laser-desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Thus, it is probable that both isozymes are tetramers. The optimum pH and temperature for coniferyl alcohol dehydrogenase activity were pH 9.5 and 45 °C for CADH I and pH 8.5 and 40 °C for CADH II. CADH I oxidized various aromatic alcohols and allyl alcohol, and was most efficient on cinnamyl alcohol, whereas CADH II exhibited high substrate specificity for coniferyl alcohol, and showed no activity as to the other alcohols, except for cinnamyl alcohol and 3-(4-hydroxy-3-methoxyphenyl)-1-propanol. In the presence of NADH, CADH I and II reduced cinnamaldehyde and coniferyl aldehyde respectively to the corresponding alcohols.
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  • Yongshun GAO, Adebanjo Ayobamidele BADEJO, Hitoshi SHIBATA, Yoshihiro ...
    2011 Volume 75 Issue 9 Pages 1783-1788
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
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    Supplementary material
    Arabidopsis thaliana contains two GDP-L-galactose phosphorylase genes, VTC2 and VTC5, which are critical for ascorbate (AsA) biosynthesis. We investigated the expression levels of both VTC2 and VTC5 genes in wild-type A. thaliana and the AsA deficient mutants during early seedling growth. Ascorbate accumulated to an equal extent in all genotypes up to 5 d post-germination (DPG). The transcript level of VTC2 was dominant, and increased in parallel with AsA accumulation in the wild type. On the other hand, the expression of VTC5 compensated for the reduced VTC2 transcription levels in the AsA deficient mutant vtc2-1 in young seedlings. A luciferase activity assay indicated that the VTC5 promoter was more active in young (2 DPG) cotyledons and that the VTC2 and VTC5 promoters drove a day-to-night variation in expression. The present work provides clues to the precise roles of VTC2 and VTC5 in AsA biosynthesis in A. thaliana at the young seedling stage.
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  • Sachiko ONO, Masahiro KUSAMA, Rieko OGURA, Kazuyuki HIRATSUKA
    2011 Volume 75 Issue 9 Pages 1796-1800
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
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    Because of their marked responsiveness to induction signals, genes encoding pathogenesis-related proteins are used as markers to monitor defense gene expression in plants. To develop a non-invasive bioluminescence reporter assay system, we tested acidic PR-1 gene promoters from tobacco and Arabidopsis. These two promoters share common regulatory elements and are believed to show similar responsiveness to various stimuli but the results of transient expression assays by microprojectile bombardment of various plant cells and npr1 mutant Arabidopsis suggest that the tobacco PR-1a promoter is superior to its Arabidopsis counterpart in terms of responsiveness to salicylic acid treatment. Transgenic Arabidopsis seedlings harboring the tobacco PR-1a promoter fused to firefly luciferase showed marked induction in response to treatment with chemicals that induce defense gene expression in plants. These results suggest that the tobacco PR-1a promoter is applicable in monitoring defense-gene expression in various plant species.
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  • Chengwei HUA, Huaxi YI, Lingxia JIAO
    2011 Volume 75 Issue 9 Pages 1807-1812
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
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    The cDNA encoding β-1,3(4)-glucanase, named PsBg16A, from Paecilomyces sp. FLH30 was cloned, sequenced, and over expressed in Pichia pastoris, with a yield of about 61,754 U mL−1 in a 5-L fermentor. PsBg16A has an open reading frame of 951 bp encoding 316 amino acids, and the deduced amino acid sequence of PsBg16A revealed that it belongs to glycoside hydrolase family 16. The purified recombinant PsBg16A had a pH optimum at 7.0 and a temperature optimum at 70 °C, and randomly hydrolyzed barley β-glucan, lichenin, and laminarin, suggesting that it is a typical endo-1,3(4)-β-glucanase (EC 3.2.1.6) with broad substrate specificity for β-glucans.
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Biochemistry & Molecular Biology Notes
Food & Nutrition Science Regular Papers
  • Yumiko SAKAI, Satoshi KOTOURA, Takeo YANO, Takashi KURIHARA, Kouji UCH ...
    2011 Volume 75 Issue 9 Pages 1639-1643
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
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    A standard plasmid was constructed as a novel reference molecule for use in real-time quantitative PCR assays to verify the identity of beef, pork, chicken, mutton, and horseflesh. The plasmid contained a target domain of the cytochrome b (cyt b) gene and an artificial DNA sequence. Primers CO-F and CO-R, and probe CO-P were specifically designed to detect the artificial sequence. The calculated R2 values of the standard curves (103–107 copies per reaction) for the five species ranged between 0.998 and 0.999 in the quantification analysis. The constructed plasmid provides a universal method for measuring the copy number of cyt b DNA in minced meat. This method would be a useful procedure for verifying food labels.
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  • Keisuke TOMOCHIKA, Akiko SHIMIZU-IBUKA, Tomoko TAMURA, Kiyoshi MURA, N ...
    2011 Volume 75 Issue 9 Pages 1644-1648
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
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    Peanut skin contains large amounts of polyphenols having antiallergic effects. We found that a peanut-skin extract (PSE) inhibits the degranulation induced by antigen stimulation of rat basophilic leukemia (RBL-2H3) cells. A low-molecular-weight fraction from PSE, PSEL, also had inhibitory activity against allergic degranulation. A main polyphenol in PSEL was purified by gel chromatography and fractionated by YMC-gel ODS-AQ 120S50 column. Electrospray ionization mass spectrometry (ESI-MS) analysis of the purified polyphenol gave mz 599 [M+Na]+. Based on the results of 1H-NMR, 13C-NMR spectra, and optical rotation analysis, the polyphenol was identified as procyanidin A1. It inhibited the degranulation caused by antigen stimulation at the IC50 of 20.3 μM. Phorbol-12-myristate-13-acetate (PMA) and 2,5,-di(tert-butyl)-1,4-hydroquinone (DTBHQ)-induced processes of degranulation were also inhibited by procyanidin A1. These results indicate that peanut-skin procyanidin A1 inhibits degranulation downstream of protein kinase C activation or Ca2+ influx from an internal store in RBL-2H3 cells.
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  • Shoji MIWA, Megumi NAKAMURA, Michiko OKUNO, Hisako MIYAZAKI, Jun WATAN ...
    2011 Volume 75 Issue 9 Pages 1649-1653
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
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    A starch ingredient with antioxidative activity, as measured by the DPPH method, was produced by baking corn starch with an organic acid; it has been named ANOX sugar (antioxidative sugar). The baking temperature and time were fixed at 170 °C and 60 min, and the organic acid used was selected from preliminary trials of various kinds of acid. The phytic acid ANOX sugar preparation showed the highest antioxidative activity, but the color of the preparation was almost black; we therefore selected L-tartaric acid which had the second highest antioxidative activity. The antioxidative activity of the L-tartaric acid ANOX sugar preparation was stable against temperature, light, and enzyme treatments (α-amylase and glucoamylase). However, the activity was not stable against variations in water content and pH value. The antioxidative activity of ANOX sugar was stabilized by treating with boiled water or nitrogen gas, or by pH adjustment.
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  • Kuo-Hsin CHEN, Ping-Chia LI, Wei-Hsiang LIN, Chiang-Ting CHIEN, Boon-H ...
    2011 Volume 75 Issue 9 Pages 1668-1676
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
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    We determined the effects of a green tea extract with 36% alcohol on the blood alcohol content, oxidative stress, lipogenesis, inflammation and liver function of female Wistar rats. Tea alcohol significantly decreased the O2, H2O2 and HOCl amounts via catechins and not caffeine. Thirty days of alcohol gavage improved the level of reactive oxygen species (ROS) in the liver, bile and blood, increased the 4-hydroxynonenal-protein adducts, Kupffer cell infiltration and lipid accumulation in the liver, and elevated the plasma alanine aminotransferase level. A western blot analysis showed reduced expression of the oxidative enzymes (CYP2E1 and NADPH oxidase p47phox protein) and lipogenic enzymes (SREBP-1c and fatty acid synthase) in the alcohol-treated liver. Tea alcohol significantly attenuated these elevated parameters. We conclude that the green tea extract in alcohol efficiently reduced the amounts of O2, H2O2 and HOCl primarily due to the catechin content, and not caffeine. The developed tea liquor attenuated alcohol-induced oxidative injury and lipogenesis in the liver by the synergetic action of catechins and caffeine.
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  • Yanqing ZANG, Hideyo SATO, Kiharu IGARASHI
    2011 Volume 75 Issue 9 Pages 1677-1684
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
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    The anti-diabetic effects of a kaempferol glycoside-rich fraction (KG) prepared from leaves of unripe Jindai soybean (Edamame) and kaempferol, an aglycone of kaempferol glycoside, were determined in genetically type 2 diabetic KK-Ay mice. The hemoglobin A1c level was decreased and tended to be decreased by respectively feeding KG and kaempferol (K). The area under the curve (AUC) in the oral glucose tolerance test (OGTT) tended to be decreased by feeding K and KG. The liver triglyceride level and fatty acid synthase activity were both decreased in the mice fed with KG and K when compared to those parameters in the control mice. These results suggest that KG and K would be useful to improve the diabetes condition. The major flavonoids in KG were identified as kaempferol 3-O-β-D-glucopyranosyl(1→2)-O-[α-L-rhamnopyranosyl(1→6)]-β-D-galactopyranoside, kaempferol 3-O-β-D-glucopyranosyl(1→2)-O-[α-L-rhamnopyranosyl(1→6)]-β-D-glucopyranoside, kaempferol 3-O-β-D-(2-O-β-D-glucopyranosyl) galactopyranoside and kaempferol 3-O-β-D-(2,6-di-O-α-L-rhamnopyranosyl) galactopyronoside, suggesting that these compounds or some of them may be concerned with mitigation of diabetes.
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  • Qian CAI, Bao-ying LI, Hai-qing GAO, Jian-hua ZHANG, Jun-fu WANG, Fei ...
    2011 Volume 75 Issue 9 Pages 1692-1697
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
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    Advanced glycation end product (AGE)-induced vascular smooth muscle cell (VSMC) proliferation is vital to the progression of diabetic vasculopathy. A grape seed procyanidin extract has been reported to possess anti-oxidative and anti-inflammatory properties and to display a significant cardiovascular protective effect, but little is know about the underlying mechanism. The objective of this present study was to determine whether GSPB2 (grape seed procyanidin B2), which is a dimeric procyanidin and more biologically active, could inhibit AGE-induced VSMC proliferation by affecting the production of ubiquitin COOH-terminal hydrolase 1 (UCH-L1), the degradation of IκB-α and nuclear translocation of NF-κB in human aortic smooth muscle cells (HASMCs). Our data show that GSPB2 preincubation markedly inhibited AGE-induced proliferation and migration of HASMCs in a dose-dependent manner and upregulated the protein level of UCH-L1. Further studies revealed that the GSPB2 pretreatment markedly attenuated the degradation of IκB-α and nuclear translocation of NF-κB by modulating ubiquitination of IκB-α in AGE-exposed HASMCs. These results collectively suggest that AGE-induced HASMC proliferation and migration was suppressed by GSPB2 through regulating UCH-L1 and ubiquitination of IκB-α. GSPB2 may therefore have therapeutic potential in preventing and treating vascular complications of diabetes mellitus.
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  • Tsutomu HASHIDUME, Takashi SASAKI, Jun INOUE, Ryuichiro SATO
    2011 Volume 75 Issue 9 Pages 1702-1707
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
    JOURNALS FREE ACCESS
    Supplementary material
    We examined to determine whether hepatic gene expression is affected in mice in which blood lipid levels remain unchanged fed soy protein isolate (SPI) for a short time. We also examined SPI-mediated effects in farnesoid X receptor (FXR)-deficient mice. Compared with casein, SPI affected the expression of various hepatic genes related to lipid metabolism in the wild-type mice. No effects of SPI were observed in the FXR-deficient mice, suggesting the importance of FXR. Hepatic peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) gene expression was reduced by SPI, and this might be associated with a decrease in FXR expression. Decreased FXR led to decreased expression of its target, the bile-salt export pump necessary for bile acid secretion and dietary lipid absorption. The earliest response to SPI was a decrease in hepatic sterol regulatory element-binding protein (SREBP)-1c mRNA, on day 3. SPI activated hepatic adenosine monophosphate-activated protein kinase (AMPK), which can lead to a reduction in SREBP-1c mRNA. These data indicate the importance of SREBP-1c and PGC-1α/FXR in SPI-mediated alterations in hepatic gene expression.
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  • Yasunori MAEJIMA, Hiroki NAKATSUGAWA, Daiki ICHIDA, Mayumi MAEJIMA, Ya ...
    2011 Volume 75 Issue 9 Pages 1708-1712
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
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    Fermented buckwheat sprouts (FBS) are used as multifunctional foods. Their production process includes fermentation with lactic acid bacteria. The major strains were found to include Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus pentosus, Lactococcus lactis subsp. lactis, and Pediococcus pentosaceus in an investigation of the lactic acid bacteria. We searched for the functional components, and nicotianamine (NA) and 2″-hydroxynicotianamine (HNA) were identified as angiotensin I-converting enzyme (ACE) inhibitors. NA and HNA increased during fermentation. Indole-3-ethanol was identified as an antioxidant (a SOD active substance), and may have been generated from tryptophan during fermentation because it was not contained in green buckwheat juice. A safety test demonstrated that FBS contained were safe functional food components, showing negative results in buckwheat allergy tests. Any buckwheat allergy substances might have been degraded during the fermentation process.
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Food & Nutrition Science Note
Microbiology & Fermentation Technology Regular Papers
  • Ryohei UENO, Naoko HAMADA-SATO, Masami ISHIDA, Naoto URANO
    2011 Volume 75 Issue 9 Pages 1654-1661
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
    JOURNALS FREE ACCESS
    Apart from Xanthophyllomyces dendrorhous, pink colony-forming yeasts have not been examined as a pigmentation source in captive animals. In this study, aquatic yeasts were screened with a view to abundances of carotenoids. Phylogenetic analyses of these caroetnoid-rich yeasts based on large subunit ribosomal RNA gene (LSU rDNA) partial sequences showed that all belonged to the order Sporidiobolales. Both the qualitative and the quantitative differences in carotenoids between the yeasts appeared to be consistent with their phylogenetic affiliations. This information might be useful in the selection of pigment-rich yeasts containing specific carotenoids from a large number of strains. We also found, for the first time, the potential of a pigment-rich Rhodotorula strain as a colorant for aquaculture. The integuments of tilapia and carp fed the alkali-treated cells of strain Rhodotorula dairenensis Sag 17 were pigmented after 3 months of cultivation. The fish integuments retained the yeast carotenes shortly after the start of feeding, and were converted to the fish-specific xanthophylls in vivo.
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  • Toshiaki YANAMOTO, Akihiro MIYAMOTO, Kayoko IKEDA, Takushi HATANO, Hir ...
    2011 Volume 75 Issue 9 Pages 1713-1721
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
    JOURNALS FREE ACCESS
    Supplementary material
    Eukaryotic cells are characterized by very large chromosomal DNAs efficiently packed within the nucleus. To identify the mechanism of chromosomal packaging based on the uniqueness of the centromere region in Saccharomyces cerevisiae, we isolated the HCH6 mutant, which shows 2.5-fold higher efficiency of site-specific recombination between the CEN5 and HIS3 loci than the wild-type CH53 strain. This mutant also displayed defects in cell integrity at high temperature. The SSD1 gene was perhaps responsible for this defect. The efficiency of site-specific recombination was decreased by the introduction of SSD1 in HCH6 cells and increased by disruption of SSD1 in the wild-type cells. Furthermore, the distances between the CEN5 and HIS3 loci and between the CEN5 locus and the spindle pole body (SPB) indicated that disrupting SSD1 caused a loss of the anchoring of the CEN5 locus near SPB. These results suggest Ssd1p-dependent cross-talk between chromosomal positioning within the nucleus and the positioning of cellular components within the cell.
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  • Yu-meng ZHOU, Lei SHAO, Ji-an LI, Li-zhong HAN, Wai-jiao CAI, Chun-bao ...
    2011 Volume 75 Issue 9 Pages 1746-1751
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
    JOURNALS FREE ACCESS
    As a large number of multidrug-resistant bacteria have emerged, and there is an urgent need for the development of new antibacterial agents. In this study, we developed a liquid-based slow killing assay to be carried out in standard 96-well microtiter plates. This screening method was designed to facilitate high-throughput screening of small molecules and extracts. In antibiotic rescue assays, the Caenorhabditis elegans multidrug-resistant Pseudomonas aeruginosa infection model displayed a high degree of drug resistance in vivo and in vitro. We used the method to screen 1,300 extracts, and found 36 extracts (2.7%) which prolonged the survival of infected nematodes, and four (0.3%) of these extracts showed in vitro and in vivo anti-multidrug resistant P. aeruginosa activity. These results indicate that the whole-animal C. elegans multidrug-resistant bacterial model can be used to screen antibacterial compounds, and can also be useful for bioactive compounds which most likely cannot be identified in vitro.
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  • Koichi MITSUKURA, Mai SUZUKI, Sho SHINODA, Tatsuya KURAMOTO, Toyokazu ...
    2011 Volume 75 Issue 9 Pages 1778-1782
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
    JOURNALS FREE ACCESS
    The (R)-imine reductase (RIR) of Streptomyces sp. GF3587 was purified and characterized. It was found to be a NADPH-dependent enzyme, and was found to be a homodimer consisting of 32 kDa subunits. Enzymatic reduction of 10 mM 2-methyl-1-pyrroline (2-MPN) resulted in the formation of 9.8 mM (R)-2-methylpyrrolidine ((R)-2-MP) with 99% e.e. The enzyme showed not only reduction activity for 2-MPN at neutral pH (6.5–8.0), but also oxidation activity for (R)-2-MP under alkaline pH (10–11.5) conditions. It appeared to be a sulfhydryl enzyme based on the sensitivity to sulfhydryl specific inhibitors. It was very specific to 2-MPN as substrate.
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  • Myung-Ji SEO, Beom-Seon LEE, Yu-Ryang PYUN, Hoon PARK
    2011 Volume 75 Issue 9 Pages 1789-1795
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
    JOURNALS FREE ACCESS
    Geobacillus caldoxylosilyticus YS-8, which was isolated from volcanic soil in Indonesia, was found to degrade various N-acylhomoserine lactones (AHLs) with different lengths and acyl side-chain substitutions over a wide temperature range of 30–70 °C. The purified AHL-degrading enzyme showed a single band of 32 kDa, and its N-terminal amino acid sequence was determined to be ANVIKARPKLYVMDN, tentatively suggesting that the AHL-degrading enzyme was AHL lactonase. The AHL-degrading activity of the purified enzyme was maximized at pH 7.5 and 50 °C, and it retained about 50% of its activity even after a heat treatment at 60 °C for 3 h, exhibiting properties consistent with a thermostable enzyme. The mass spectrometric analysis demonstrated that the AHL-degrading enzyme catalyzed lactone ring opening of N-3-oxohexanoyl-L-homoserine lactone and N-hexanoyl-L-homoserine lactone by hydrolyzing the lactones and working as an AHL lactonase.
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  • Osao ADACHI, Roque A. HOURS, Emiko SHINAGAWA, Yoshihiko AKAKABE, Toshi ...
    2011 Volume 75 Issue 9 Pages 1801-1806
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
    JOURNALS FREE ACCESS
    In our previous study, a new microbial reaction yielding 4-keto-D-arabonate from 2,5-diketo-D-gluconate was identified with Gluconacetobacter liquefaciens RCTMR 10. It appeared that decarboxylation and dehydrogenation took place together in the reaction. To analyze the nature of the reaction, investigations were done with the membrane fraction of the organism, and 4-keto-D-arabinose was confirmed as the direct precursor of 4-keto-D-arabonate. Two novel membrane-bound enzymes, 2,5-diketo-D-gluconate decarboxylase and 4-keto-D-aldopentose 1-dehydrogenase, were involved in the reaction. Alternatively, D-arabonate was oxidized to 4-keto-D-arabonate by another membrane-bound enzyme, D-arabonate 4-dehydrogenase. More directly, D-arabinose oxidation was examined with growing cells and with the membrane fraction of G. suboxydans IFO 12528. 4-Keto-D-arabinose, the same intermediate as that from 2,5-diketo-D-gluconate, was detected, and it was oxidized to 4-keto-D-arabonate. Likewise, D-ribose was oxidized to 4-keto-D-ribose and then it was oxidized to 4-keto-D-ribonate. In addition to 4-keto-D-aldopentose 1-dehydrogenase, the presence of a novel membrane-bound enzyme, D-aldopentose 4-dehydrogenase, was confirmed in the membrane fraction. The formation of 4-keto-D-aldopentoses and 4-keto-D-pentonates (4-pentulosonates) was finally confirmed as reaction products of four different novel membrane-bound enzymes.
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Microbiology & Fermentation Technology Note
Microbiology & Fermentation Technology Communication
  • Bum-Yeol HWANG, Byung-Gee KIM, June-Hyung KIM
    2011 Volume 75 Issue 9 Pages 1862-1865
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
    JOURNALS FREE ACCESS
    To improve the conventional bacterial surface display systems and to display a co-factor containing enzyme, ω-transaminase from Vibrio fluvialis, which needs pyridoxal phosphate (PLP) for efficient transamination, Bacillus subtilis spore display system with cotG, as an anchoring motif was used. Flow cytometry of the B. subtilis spore-expressing ω-transaminase proved its surface localization on the spore. The enzymatic activity of the spore expressing ω-transaminase was more than 30 times higher than that of the host spore. Protease treatment of the ω-transaminase displaying spores resulted in decreased transaminase activity, which is in keeping with the surface location of the fusion protein, CotG-ω-transaminase.
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Environmental Science Regular Paper
  • Takashi NARIHIRO, Tomoyuki HORI, Osamu NAGATA, Tamotsu HOSHINO, Isao Y ...
    2011 Volume 75 Issue 9 Pages 1727-1734
    Published: September 23, 2011
    Released: September 23, 2011
    [Advance publication] Released: September 07, 2011
    JOURNALS FREE ACCESS
    Over the years, the wetlands covered by Sphagnum in Bibai, Japan have been turning into areas of aridity, resulting in an invasion of Sasa into the bogs. Yet little is known about the methane-cycling microorganisms in such environments. In this study, the methanotrophic, methanogenic, and archaeal community structures within these two types of wetland vegetation were studied by phylogenetic analysis targeting particulate methane monooxygenase (pmoA), methyl coenzyme M reductase (mcrA), and the archaeal 16S rRNA gene. The pmoA library indicated that Methylomonas and Methylocystis predominated in the Sphagnum-covered and Sasa-invaded areas, respectively. The mcrA and 16S rRNA libraries indicated that Methanoregula were abundant methanogens in the Sphagnum-covered area. In the Sasa-invaded area, by contrast, mcrA genes were not detected, and no 16S rRNA clones were affiliated with previously known methanogens. Because the Sasa-invaded area still produced methane, of the various uncultured populations detected, novel euryarchaeotal lineages are candidate methane producers.
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