Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
Volume 73 , Issue 11
Showing 1-41 articles out of 41 articles from the selected issue
Organic Chemistry Regular Paper
Organic Chemistry Notes
Biochemistry & Molecular Biology Regular Papers
  • Somporn TANSKUL, Kazumi HIRAGA, Katsumi TAKADA, Suchart RUNGRATCHOTE, ...
    2009 Volume 73 Issue 11 Pages 2393-2398
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
    JOURNALS FREE ACCESS
    An alkaline serine-proteinase from Bacillus sp. PN51 isolated from bat feces collected in Phang Nga, Thailand, was purified and characterized. The molecular mass was estimated to be 35.0 kDa. The N-terminal 25 amino acid sequence was about 70% identical with that of Natrialba magadii halolysin-like extracellular serine protease. The enzyme showed the highest proteinase activity at 60 °C at pH 10.0. The activity was strongly inhibited by PMSF and chymostatin. The proteinase activity was not affected by the presence of 2% urea, 2% H2O2, 12% SDS, 15% triton X-100, or 15% tween 80. The proteinase preferred Met, Leu, Phe, and Tyr residues at the P1 position, in descending order. The kcat, Km and kcat/Km values for Z-Val-Lys-Met-MCA were 16.8±0.14 min−1, 5.1±0.28 μM, and 3.3±0.28 μM−1 min−1 respectively. This is the first report of an alkaline serine-proteinase with extremely high stability against detergents such as SDS.
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  • Shinya YAMADA, Toshiya OHTA, Chikayo IIZUKA, Kazumichi OZAWA, Yoshihir ...
    2009 Volume 73 Issue 11 Pages 2399-2407
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
    JOURNALS FREE ACCESS
    We report here the isolation and molecular characterization of single-chain Fv (scFv) antibodies raised against two major allergens, Cryj1 and Cryj2, in the pollen of Cryptomeria japonica by the phage display method. Recombinant phages that produced scFv antibodies that bound to Cryj1 or Cryj2 were isolated by selection with immobilized antigens in microtiter plates. After selection of six Cryj1- and four Cryj2-specific scFv antibodies with strong binding activity, we performed pairwise interaction analysis of them by surface plasmon resonance. The analysis revealed that the scFv antibodies against Cryj1 bound to only four non-overlapping epitopes, with dissociation constants that ranged from 4.84×10−9 M to 1.62×10−7 M. By contrast, four Cryj2-specific scFv antibodies inhibited each other’s binding to Cryj2, with dissociation constants from 1.11×10−7 M to 4.21×10−7 M. Our results indicate that recombinant technology provides a time-saving method for the production of antibodies against pollen allergens.
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  • Takuya KOJIMA, Naoki TAKAHASHI
    2009 Volume 73 Issue 11 Pages 2416-2421
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
    JOURNALS FREE ACCESS
    Supplementary material
    In normal development, each gene correctly expresses under temporal and spatial regulation. Teratogenic agents among environmental contaminants induce aberrated gene expression and consequently lead to congenital malformations. Therefore, it is urgent to identify molecular markers for the detection of teratogenic agents’ effects.
    We analyzed mouse 39 hox gene expression in teratogenic factor exposed embryos. We found that 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) and retinoic acid (RA) affected differentially expression of hox. Unlike the RA-effects, TCDD led to broad repression of all hox loci. This different effect was also detected in miRNAs (microRNAs) expression in hox loci. Our results indicate that this irregular hox expression is a cause of congenital malformation, and suggest that monitoring of all hox expression works as a marker for environmental contaminants, including teratogenic effects.
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  • Wen-Jun CHANG, Huo-Sheng SU, Wei-Jing LI, Zhi-Li ZHANG
    2009 Volume 73 Issue 11 Pages 2427-2431
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
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    A full-length cDNA LeCPK2 (GenBank GQ205414) from tomato (Solanum lycopersicum) encoding a calcium-dependent protein kinase (CDPK) was cloned by in silico cloning using NtCPK5 (AY971376) as a virtual probe. The deduced amino acid sequence of LeCPK2 contained the kinase, autoinhibitory, and calmodulin-like domains typical of CDPKs. Expression profiling indicated that LeCPK2 expressed predominantly in flowers and responded divergently to heat and cold stress, in which obvious mRNA accumulation was detected at 4 h under 42 °C stress, but no change in LeCPK2 mRNA levels was observed in 6 h at 4 °C. Mechanical wounding and phytohormones including ethylene, methyl jasmonate, and salicylic acid were also observed to arouse the expression of LeCPK2 in a similar pattern. mRNA accumulation was enhanced at 30 min and reached a maximum at 3 h, followed by a decrease to the normal level. All the results suggest that LeCPK2 is a novel versatile isoform of tomato CDPKs.
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  • Kiyoshi MASHIGUCHI, Tadao ASAMI, Yoshihito SUZUKI
    2009 Volume 73 Issue 11 Pages 2452-2459
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
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    Supplementary material
    Early nodulin-like proteins (ENODLs) are chimeric arabinogalactan proteins (AGPs) related to the phytocyanin family. Although they show similarities with other phytocyanins, they lack amino acid residues for copper binding. Despite the existence of other phytocyanins, information about the function of ENODLs in plants is largely lacking. In this study, we characterized ENODL genes consisting of 22 members in Arabidopsis thaliana. Structure prediction indicated that most ENODLs are glycosylphosphatidylinositol-anchored chimeric AGPs. Expression analysis by real-time reverse transcription polymerase chain reaction indicated that most ENODL genes showed spatially specific expression, mainly in the flower organs. Furthermore, we obtained and analyzed 26 homozygous T-DNA insertion lines of 15 ENODL genes, but novel biological roles were not uncovered, probably due to functional redundancy. The detailed phylogenetic and expression analyses and characterization of the available insertion lines in this study might facilitate future studies to elucidate the biological roles of ENODLs.
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  • Kiyoshi MASHIGUCHI, Eriko SASAKI, Yukihisa SHIMADA, Miyu NAGAE, Kotomi ...
    2009 Volume 73 Issue 11 Pages 2460-2465
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
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    Supplementary material
    Strigolactones (SLs) have recently been found to regulate shoot branching, but the functions of SLs at other stages of development and the regulation of SL-related gene expression are mostly unknown in Arabidopsis. In this study, we performed real-time reverse transcription-PCR (RT-PCR) and microarray analysis using wild-type plants and SL-deficient/insensitive mutants to understand the molecular mechanisms underlying SL biosynthesis and signaling. We found that there is responsiveness to SL in the gene expression of Arabidopsis seedlings, which includes feedback regulation of two carotenoid cleavage dioxygenase genes. Microarray analysis revealed that exogenously applied SL regulated the expression of several genes, including light signaling-related genes and auxin-inducible genes. We also found that MORE AXILLARY GROWTH (MAX)2 plays an important role in the expression of SL-regulated genes. Our data support previous studies indicating that SL might function at the seedling stage. Analysis of SL-responsive and MAX2 downstream gene candidates provides new opportunities to broaden our understanding of SL signaling.
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  • Haruhide MORI, Jin-Ha LEE, Masayuki OKUYAMA, Mamoru NISHIMOTO, Masao O ...
    2009 Volume 73 Issue 11 Pages 2466-2473
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
    JOURNALS FREE ACCESS
    Trehalase, an anomer-inverting glycosidase, hydrolyzes only α,α-trehalose in natural substrates to release equimolecular β-glucose and α-glucose. Since the hydrolytic reaction is reversible, α,α-[1,1′-2H]trehalose is capable of synthesis from [1-2H]glucose through the reverse reaction of trehalase. α-Secondary deuterium kinetic isotope effects (α-SDKIEs) for the hydrolysis of synthesized α,α-[1,1′-2H]trehalose by honeybee trehalase were measured to examine the catalytic reaction mechanism. Relatively high kHkD value of 1.53 for α-SDKIEs was observed. The data imply that the catalytic reaction of the trehalase occurs by the oxocarbenium ion intermediate mechanism. In addition, the hydrolytic reaction of glycosidase is discussed from the viewpoint of chemical reactivity for the hydrolysis of acetal in organic chemistry. As to the hydrolytic reaction mechanism of glycosidases, oxocarbenium ion intermediate and nucleophilic displacement mechanisms have been widely recognized, but it is pointed out for the first time that the former mechanism is rational and valid and generally the latter mechanism is unlikely to occur in the hydrolytic reaction of glycosidases.
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  • Miroslava ĎURANOVÁ, Ján HIRSCH, Katarína KOL ...
    2009 Volume 73 Issue 11 Pages 2483-2487
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
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    Glucuronoyl esterases are enzymes involved in microbial plant cell-wall degradation. In this study we purified and characterized two recombinant Phanerochaete chrysosporium glucuronoyl esterases, PcGE1 and PcGE2. The catalytic activity of these and previously described glucuronoyl esterases was investigated on new synthetic substrates, methyl esters of uronic acids and their glycosides, prepared by esterification with ethereal diazomethane.
    The data obtained indicate that the enzymes hydrolyzed efficiently not only esters of 4-O-methyl-D-glucuronic acid, but also methyl esters of D-glucuronic acid carrying a 4-nitrophenyl aglycon. Moreover, the fact that they did not recognize the 4-epimers of these compounds, the D-galacturonic acid derivatives, supports the hypothesis that these carbohydrate esterases attack ester linkages between 4-O-methyl-D-glucuronic acid of glucuronoxylan and lignin alcohols.
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  • Hirohumi INOUE, Moussa NDONG, Tsukasa SUZUKI, Machiko KAZAMI, Takumi U ...
    2009 Volume 73 Issue 11 Pages 2488-2493
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
    JOURNALS FREE ACCESS
    Supplementary material
    Hamartin and tuberin interact directly to regulate cell growth negatively. In this study, far-western blotting revealed that hamartin binds directly Heat shock protein 70 (Hsp70), even in the absence of tuberin. While the hamartin-tuberin complex acts as a sensor for a variety of types of stress, it is unclear how the complex is regulated under stress conditions. We found that the hamartin-Hsp70 interaction is stabilized during heat shock. On the other hand, tuberin underwent degradation through phosphorylation in an Akt-dependent manner. Furthermore, we found that when Hsp70 expression was inhibited by N-formyl-3,4-methylenedioxy-benzylidene-γ-butyrolactam (KNK437), Akt phosphorylation on site Ser308 diminished and tuberin was not phosphorylated at Thr1462 during heat shock. We conclude that both hamartin and Hsp70 increase in response to heat shock, whereas tuberin is phosphorylated and thereafter degraded via the PI3K/Akt pathway. Through this pathway, hamartin-Hsp70 plays a crucial role as a scaffolding protein that transfers the Akt signal to tuberin.
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Biochemistry & Molecular Biology Notes
Biochemistry & Molecular Biology Communication
  • Shinya NAKAMURA, Akihide NAKAO, Makoto KAWAMUKAI, Tetsuya KIMURA, Sumi ...
    2009 Volume 73 Issue 11 Pages 2556-2559
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
    JOURNALS FREE ACCESS
    We developed a new series of Gateway binary vectors for plant transformation, R4L1pGWBs, which allow easy construction of promoter:reporter clones. R4L1pGWBs contain a recombination attR4-attL1-reporter cassette, and thus an attL4-promoter-attR1 entry clone was efficiently incorporated by the Gateway LR reaction, resulting in the generation of an attB4-promoter-attB1-reporter construct. The reporters employed in R4L1pGWBs were β-glucuronidase (GUS), luciferase (LUC), enhanced yellow fluorescent protein (EYFP), enhanced cyan fluorescent protein (ECFP), G3 green fluorescent protein (G3GFP), G3GFP-GUS, and tag red fluorescent protein (TagRFP).
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Food & Nutrition Science Regular Papers
  • Mei LIU, Yan LUO, Ran TAO, Ru HE, Keyong JIANG, Baojie WANG, Lei WANG
    2009 Volume 73 Issue 11 Pages 2365-2369
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
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    Using the LAMP method, a highly specific and sensitive detection system for genetically modified soybean (Roundup Ready) was designed. In this detection system, a set of four primers was designed by targeting the exogenous 35S epsps gene. Target DNA was amplified and visualized on agarose gel within 45 min under isothermal conditions at 65 °C. Without gel electrophoresis, the LAMP amplicon was visualized directly in the reaction tube by the addition of SYBR Green I for naked-eye inspection. The detection sensitivity of LAMP was 10-fold higher than the nested PCR established in our laboratory. Moreover, the LAMP method was much quicker, taking only 70 min, as compared with 300 min for nested PCR to complete the analysis of the GM soybean. Compared with traditional PCR approaches, the LAMP procedure is faster and more sensitive, and there is no need for a special PCR machine or electrophoresis equipment. Hence, this method can be a very useful tool for GMO detection and is particularly convenient for fast screening.
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  • Mamoru TANIDA, Nobuo TSURUOKA, Jiao SHEN, Yuko HORII, Yoshinori BEPPU, ...
    2009 Volume 73 Issue 11 Pages 2374-2378
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
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    In a previous report, evidence was presented that flavangenol supplementation has an anti-ischemic effects in rats. In the study presented here, we examined the autonomic effects of intraduodenal (ID) injection of flavangenol in urethane-anesthetized rats and found that it increased sympathetic nerve activity innervating brown adipose tissue (BAT-SNA) in a dose-dependent manner, while it suppressed gastric vagal nerve activity (GVNA). In addition, intra-oral (IO) injection of flavangenol elevated brown adipose tissue temperature (BAT-T). Furthermore, flavangenol drinking for 15 d reduced body weight gain in rats fed a high-fat diet. These results thus suggest that flavangenol supplementation exerts its reducing action on body weight through changes in autonomic neurotransmission.
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  • Keiko YAMAGUCHI, Yuri NOUMI, Katsumi NAKAJIMA, Chiharu NAGATSUKA, Haru ...
    2009 Volume 73 Issue 11 Pages 2379-2383
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
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    The reaction between the amino group and the carbonyl group is important in food quality control. Furthermore, advanced glycation end products from foods are considered to relate to aging and diabetes. Thus, it is important to control this reaction. In this study, we investigated the effects of salt concentration on the rates of browning reaction of amino acid, peptides, and proteins. A high concentration of sodium chloride retarded the reaction rate of Glc with amino acids as measured with the absorbance at 470 nm, but did not change the browning rate of Glc with peptides. On the other hand, sodium chloride retarded the browning reaction rate of proteins as measured with polymerization degree or by the loss of Lys. It is hoped that the results of this study will be applied in the control of amino-carbonyl reaction rates in the food industry.
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  • Sunmin PARK, Sang Mee HONG, Il Sung AHN, Yang Jin KIM, Jung Bok LEE
    2009 Volume 73 Issue 11 Pages 2384-2392
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
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    We investigated to determine what effects, if any, the respective water extracts of Radix scutellariae (RS), Fructus schisandrae chinensis (FSC), Huang-Lian-Jie-Du-Tang (HLJDT), and HLJDT supplemented with FSC, and Rhizoma Polygonati odorati (HLJDT-M) would have on glucose tolerance by modulating glucose-stimulated insulin secretion, β-cell mass, and morphometry in 90% pancreatectomized (Px) diabetic rats fed high-fat diets. Through the elevation of intracellular cAMP levels, FSC RS, HLJDT, and HLJDT-M increased insulin secretion in Min6 cells and GLP-1 secretion in NCI-H716 cells. After an 8-week period of treatment, it was found that HLJDT-M improved glucose tolerance in an oral glucose tolerance test in Px rats. HLJDT-M also potentiated first- and second-phase insulin secretion, but RS and HLJDT elevated only the second phase at hyperglycemic clamp. RS and HLJDT increased β-cell mass by hyperplasia and hypertrophy, while HLJDT-M increased it only by hyperplasia. The rise in hyperplasia was associated with elevated IRS2 and PDX-1 expression in the islets. In conclusion, HLJDT-M worked as an anti-diabetic prescription by enhancing insulinotropic actions in diabetic rats.
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  • Yuri NOMI, Haruko AIZAWA, Tadao KURATA, Kazutoshi SHINDO, Chuyen Van N ...
    2009 Volume 73 Issue 11 Pages 2408-2411
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
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    The elevation of such dicarbonyl compounds as glyoxal and the depletion of GSH occur simultaneously in diabetic patients. Enabling a nonenzymatic glycation reaction with GSH and glyoxal is therefore proposed. However, the reaction mechanism for GSH and glyoxal has not been precisely defined. We isolated in this study the major products obtained by the reaction of GSH and glyoxal under physiological conditions, and clarified the chemical structure of these compounds by MS and NMR analyses for the first time. We identified the major product after 24 h as N-[3-(2,5-dioxomorpholin-3-yl)propanoyl]cysteinylglycine, and the one after 30 min as N-glycoloyl-γ-glutamylcysteinylglycine (the intermediate of the former compound). Our results suggest that GSH reacted with glyoxal at the α-NH2 group of the glutamate residue, but not at the SH group of the cysteine residue.
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  • Zhaohui XUE, Wancong YU, Moucheng WU, Jiehua WANG
    2009 Volume 73 Issue 11 Pages 2412-2415
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
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    The antitumor and antioxidative activities of a rapeseed protein hydrolysate (RSCH) obtained from rapeseed meal were evaluated by using an in vivo S180 tumor-bearing Kunming mice model. Tumor-bearing female mice were given RSCH for 10 at doses of 0, 50, 100, and 150 mg/kg/d by gastric perfusion. RSCH significantly decreased the tumor weight by 44% and 53% in the 100 and 150 mg/kg/d groups, respectively, without causing mortality or growth retardation. The thymus and spleen indices (organ weight relative to body weight) were increased significantly in the 150 mg/kg/d group. The phagocytic capability of coeliac macrophages and delayed-type hypersensitivity (DTH) were significantly increased in tumor-bearing mice treated with RSCH at 150 mg/kg/d. RSCH administration also enhanced the superoxide dismutase activity and reduced the serum level of thiobarbituric acid reactive substances. Our results show that an oral RSCH administration had an antitumor protective effect and may improve immune function by reducing free radical formation and oxidative stress in a murine model.
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  • Tetsunosuke MOCHIZUKI, Hideo SATSU, Mamoru TOTSUKA, Makoto SHIMIZU
    2009 Volume 73 Issue 11 Pages 2422-2426
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
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    The effect of interleukin-4 (IL-4), a cytokine associated with allergy and inflammation, on the permeability of the intestinal epithelium was investigated. IL-4 reduced transepithelial electrical resistance (TER) and increased permeation to horseradish peroxidase (HRP) and Lucifer Yellow (LY) of human intestinal T84 cell monolayers. The increased permeation due to IL-4 treatment was also observed at 4 °C. The permeability of T84 cell monolayers to β-lactogulobulin (β-Lg), ovalbumin (OVA), and fluorescein isothiocyanate (FITC)-dextran of various molecular sizes was also high in the IL-4-treated cell monolayers. Sodium azide (NaN3), which inhibits ATP synthesis of the cells, did not inhibit the increases in these substances. Even 150 kDa FITC-dextran significantly permeated the T84 cells when the monolayers were treated with IL-4. These results suggest that fairly large molecules are able to permeate intestinal epithelial monolayers via the energy-independent paracellular pathway when the monolayers are exposed to excessive IL-4.
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  • Kazuhiro KUBO, Seiji SEKINE, Morio SAITO
    2009 Volume 73 Issue 11 Pages 2432-2438
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
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    We have hypothesized a suppressive mechanism against dietary docosahexaenoic acid (22:6n-3; DHA)-induced tissue lipid peroxidation, in which the degradation products, including their conjugates, are excreted into the urine by xenobiotic or organic anion transporters. In this study, we employed parent-strain Sprague-Dawley rats (SDRs), together with their mutant strain, Eisai hyperbilirubinuria rats (EHBRs). EHBRs are deficient in multidrug resistance-associated protein (MRP) 2, and show defective urinary excretion of numerous xenobiotics and organic anions. Both strains of rats were fed a diet containing DHA at 8.4% of total energy for 31 d. In the livers of the DHA-fed rats, the level of free malondialdehyde (MDA) + 4-hydroxy-2-alkenals (HAE) fell, and conversely glutathione S-transferase (GST) activity increased in MRP2-deficient EHBRs as compared to the SDRs, suggesting that the glutathione (GSH)-conjugation reaction for the aldehydes generated on DHA intake was accelerated in the MRP2-deficient EHBRs. Since the gene expression of liver MRP3 in the MRP2-deficient EHBRs was amplified to compensate for DHA intake, it is thought that the transport of MRP3 substrates into the bloodstream, rather than MRP2-mediated excretion of its substrates into the bile, was promoted. Indeed, excretion of mercapturic acid (acetylcysteine conjugates derived metabolically from the conjugate of each aldehyde with GSH) into the urine increased significantly in MRP2-deficient EHBRs fed DHA.
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  • Masao GOTO, Kohji YAMAKI, Hiroshi SHINMOTO, Yuko TAKANO-ISHIKAWA
    2009 Volume 73 Issue 11 Pages 2439-2444
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
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    Coffee is a globally consumed beverage. Although recent studies have suggested that coffee reduced the risk of lifestyle-related diseases, there are few studies regarding allergic response.
    This study investigates the effects of orally administered coffee (91 ml/kg/d) on allergic responses using a T cell receptor (TCR)-transgenic DO11.10 mouse allergic model. Splenocytes from coffee-administered naïve mice increased antigen (Ag)-specific interleukin (IL)-12p40 secretion. When Ag sensitization and coffee administration were concurrently performed, the splenocytes from coffee-administered mice showed a decrease of IL-2 and an increase of IL-12p40 secretion. The Ag-specific cutaneous response and serum IgE level were reduced in coffee-administered mice, although, after establishing the allergy, coffee administration did not suppress the allergic reaction.
    These results suggest that coffee could induce a Th1-type response of the immune system and prevent an allergy developing. Further studies on the optimum dose, cultivar differences, and roasted degree need to be undertaken.
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  • Shigeaki UENO, Ryo SHIRAKASHI, Ken-ichi KUDOH, Toshiro HIGUCHI, Gab-So ...
    2009 Volume 73 Issue 11 Pages 2478-2482
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
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    The effect of the grain boundary of ice crystals in a frozen gelatin solution on the dielectric properties was investigated by the combination of a dielectric spectrometer and image analysis. A micro-slicer image processing system (MSIPS) was applied to measure the grain boundary properties as the perimeter density and number density of ice crystals. The perimeter density and number density of the ice crystals increased with increasing freezing rate. The dielectric properties of the frozen gelatin solution at various freezing rates were measured in the frequency range of 100 Hz to 100 kHz at −40 °C. The relaxation time did not affect the grain boundary properties. The perimeter density and number density significantly affected dielectric parameter ε0−ε and electrical conductivity σ0. These results indicate that the dielectric spectrometer could be used to estimate the grain boundary properties in a frozen gelatin solution.
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  • Mizuka NAGAI, Yoshiyuki WATANABE, Masato NOMURA
    2009 Volume 73 Issue 11 Pages 2501-2505
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
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    Acyl arbutin was synthesized through the condensation of arbutin with a saturated fatty acid (C6-18) by the immobilized lipase in a batch reaction. The conversion at 10 and 20 g/l-solvent of immobilized lipase reached 45% over 2 d, but the initial reaction rate per amount of immobilized lipase decreased at 20 g/l-solvent. The radical scavenging activity of acyl arbutin in an ethanol solution was independent of the acyl chain length, although the rate constant, k, estimated for the oxidation of methyl linoleate in a bulk system with acyl arbutin by using the Weibull equation, decreased as the acyl chain length increased. This indicates the antioxidative ability of acyl arbutin with a long acyl chain to be due to its lipophilicity. Furthermore, it is suggested that dodecanoyl arbutin mainly acted on the interface between the oil and water phases in an O/W emulsion, and effectively suppressed the oxidation induced at the interface.
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  • Yumi NAKAMURA, Koki YABE, Ken-ichiro SHIMADA, Keiko SASAKI, Kyu-Ho HAN ...
    2009 Volume 73 Issue 11 Pages 2506-2512
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
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    We examined the effects of fermented bean pastes derived from bean vinegar by-products on serum cholesterol in rats. The rats were fed boiled paste from adzuki (A), kintoki (K), or tebou (T), or fermented paste from adzuki (AP), kintoki (KP), or tebou (TP) for 4 weeks. The serum non-high-density lipoprotein (HDL) cholesterol levels in all the experimental groups, except for A group, were significantly lower than in the control (CN) group. Likewise, the serum triglyceride levels in K and all the fermented bean groups were significantly lower than in the CN group. The levels of hepatic 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase mRNA in all the experimental groups except for A were significantly lower than in the CN group. These findings indicate that fermented bean pastes also suppress cholesterol synthesis, resulting in a reduced serum cholesterol concentration. These effects might be related not only to the resistant starch but also to the protein or peptide in the fermented bean paste.
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Food & Nutrition Science Note
  • Rui-Mei LI, Xin-Wen HU, Kai-Mian LI, Shao-Ping FU, Jian-Chun GUO
    2009 Volume 73 Issue 11 Pages 2513-2515
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
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    Primary cassava somatic embryos were induced on a medium without CaCl2, however, no or only a few secondary somatic embryos were formed from them. With 15 mM CaCl2 in the medium for induction of cassava primary embryos, more secondary somatic embryos were produced from them, and they were much effective in maintaining their embryogenic capacity than the controls of embryos which were induced without CaCl2.
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Microbiology & Fermentation Technology Regular Papers
  • Takashi NEMOTO, Jun-ichi MARUYAMA, Katsuhiko KITAMOTO
    2009 Volume 73 Issue 11 Pages 2370-2373
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
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    Aspergillus oryzae RIB40 has three α-amylase genes (amyA, amyB, and amyC), and secretes α-amylase abundantly. However, large amounts of endogenous secretory proteins such as α-amylase can compete with heterologous protein in the secretory pathway and decrease its production yields. In this study, we examined the effects of suppression of α-amylase on heterologous protein production in A. oryzae, using the bovine chymosin (CHY) as a reporter heterologous protein. The three α-amylase genes in A. oryzae have nearly identical DNA sequences from those promoters to the coding regions. Hence we performed silencing of α-amylase genes by RNA interference (RNAi) in the A. oryzae CHY producing strain. The silenced strains exhibited a reduction in α-amylase activity and an increase in CHY production in the culture medium. This result suggests that suppression of α-amylase is effective in heterologous protein production in A. oryzae.
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  • Ayumu KONNO, Yoshihisa SUZUKI, Tomohisa OGAWA, Tetsuo TANIUCHI
    2009 Volume 73 Issue 11 Pages 2474-2477
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
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    Yeasts of the genus Lipomyces are known as fat yeasts, and they store large amounts of lipids. Because the major lipid produced by Lipomyces is triglyceride, which can be used as a food and energy resource, the control of lipid production by Lipomyces sp. is an important issue. Here we report the effects of UV irradiation on lipid production in Lipomyces lipofer cells. UV irradiation (315–400 nm) led to a 4-fold increase in the amount of triglyceride per cell. We discovered a novel phenomenon, that UV irradiation promotes triglyceride accumulation in L. lipofer.
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  • Chitose MARUYAMA, Yoshimitsu HAMANO
    2009 Volume 73 Issue 11 Pages 2494-2500
    Published: November 23, 2009
    Released: November 23, 2009
    [Advance publication] Released: November 07, 2009
    JOURNALS FREE ACCESS
    The streptothricin hydrolase (SttH), which is a member of the isochorismatase-like hydrolase (ILH) super-family, catalyzes the hydrolysis of the streptolidine lactam group in streptothricin (ST) antibiotics, thereby inactivating them. In this study we identified a novel homologous gene (sttH-sn) and sequenced the flanking regions of the sttH and sttH-sn genes. The organization of genes around the sttH, sttH-sn, and ILH genes revealed that a number of the genes were clustered with genes encoding oxidoreductases with molybdopterin binding subunits, suggesting that the true role of these gene products (SttHs and a number of ILHs) might have to do with the chemical modification of molybdopterin, rather than ST-resistance. In addition, mutant enzymes were constructed in which Ser was substituted for highly conserved Cys-176 and Cys-158 of SttH and SttH-sn respectively, and no enzyme activities were detected. Thus, biochemically, these ILHs were found to be “cysteine hydrolases.”
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