Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
Volume 72 , Issue 11
Showing 1-44 articles out of 44 articles from the selected issue
Organic Chemistry Regular Papers
  • Yoko NAKAMURA, Ryoji MIYATAKE, Sho INOMATA, Minoru UEDA
    2008 Volume 72 Issue 11 Pages 2867-2876
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    Albizzia saman, a leguminous plant, is known to open its leaves in the daytime and sleep at night with the leaves folded. β-D-Glucopyranosyl 12-hydroxyjasmonate (1) was isolated as an endogenous chemical factor controlling this leafmovement. We developed a concise synthesis of optically pure (−)-1 in 9 steps from (+)-2 with a total yield of 58%. Similarly, such analogs of 1 as epi-LCF (13), enantiomer (14), and galactoside (19) were synthesized for a structure activity relationship (SAR) study. The results of this SAR study strongly suggest that the mechanism for the leaf-closing activity of 1 would be different from that of methyl jasmonate, and also suggest the involvement of a different kind of target protein which recognizes the trans-isomer of a jasmonate derivative.
    Download PDF (184K)
  • Satoshi YAMAUCHI, Toshiya MASUDA, Takuya SUGAHARA, Yuya KAWAGUCHI, May ...
    2008 Volume 72 Issue 11 Pages 2981-2986
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    The antioxidant activity of butane-type lignans was evaluated. Secoisolariciresinol (SECO) and dihydroguaiaretic acid (DGA) showed higher radical scavenging activity than that of 7,7′-dioxodihydroguaiaretic acid (ODGA). SECO and DGA inhibited the oxidation of unsaturated fatty acid. Both enantiomers of DGA were also lipoxygenase inhibitors, but neither enantiomer of SECO inhibited the lipoxygenase activity.
    Download PDF (142K)
  • Yuuki SATO, Hiroshi KAMIYAMA, Takeo USUI, Tamio SAITO, Hiroyuki OSADA, ...
    2008 Volume 72 Issue 11 Pages 2992-2997
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    Analogs of cortistatins, a series of anti-angiogenic compounds isolated from the Indonesian marine sponge Cortisium simplex, were synthesized from estrone by using the Suzuki-Miyaura coupling reaction as the key step. The estrone-isoquinoline hybridized compound showed selective inhibitory activity against the proliferation and VEGF-induced migration of HUVEC.
    Download PDF (130K)
Organic Chemistry Note
Organic Chemistry Communication
Biochemistry & Molecular Biology Regular Papers
  • Nhuan Thi VU, Hiroaki SHIMADA, Yoshimitsu KAKUTA, Takashi NAKASHIMA, H ...
    2008 Volume 72 Issue 11 Pages 2858-2866
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    Starch branching enzyme (SBE) catalyzes the cleavage of α-1.4-linkages and the subsequent transfer of α-1.4 glucan to form an α-1.6 branch point in amylopectin. We overproduced rice branching enzyme I (BEI) in Escherichia coli cells, and the resulting enzyme (rBEI) was characterized with respect to biochemical and crystallographic properties. Specific activities were calculated to be 20.8 units/mg and 2.5 units/mg respectively when amylose and amylopectin were used as substrates. Site-directed mutations of Tyr235, Asp270, His275, Arg342, Asp344, Glu399, and His467 conserved in the α-amylase family enzymes drastically reduced catalytic activity of rBEI. This result suggests that the structures of BEI and the other α-amylase family enzymes are similar and that they share common catalytic mechanisms. Crystals of rBEI were grown under appropriate conditions and the crystals diffracted to a resolution of 3.0 Å on a synchrotron X-ray source.
    Download PDF (288K)
  • Mayumi SATO, Kazuto SEKI, Kazuhito KITA, Yoshinari MORIGUCHI, Keita YU ...
    2008 Volume 72 Issue 11 Pages 2895-2902
    Published: November 23, 2008
    Released: November 23, 2008
    JOURNALS FREE ACCESS
    Supplementary material
    Fatty acid (FA) compositions in leaves were investigated for two families of F1 hybrids of Larix gmelinii var. japonica × L. kaempferi (F1) and their parent clones. Twenty-one FAs, from C12 to C32, were found in the leaves of both adult trees and seedlings. The levels of 18:1/(18:2 + 18:3) increased in the order L. kaempferi, F1, and L. gmelinii var. japonica, with significant differences between L. gmelinii var. japonica and F1 in adult trees, but these differences were not found in the seedlings. Moreover, in the adult trees, the 18:1/(18:2 + 18:3) levels in the neutral phospholipid fraction and the ΣC18/ΣC16, especially in the glycolipid fraction, showed significant differences among the three species. These characteristics are discussed from the viewpoint of lipid synthesis in the endoplasmic reticulum and chloroplasts, and of the activities and substrate specificities in sequential FA desaturation. Linear discriminant analysis suggested that the FA compositions are useable as an index in the identification of hybrid seedlings.
    Download PDF (156K)
  • Tomoki SANDO, Shinya TAKENO, Norie WATANABE, Hiroshi OKUMOTO, Tomohisa ...
    2008 Volume 72 Issue 11 Pages 2903-2917
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    Natural rubber is synthesized as rubber particles in the latex, the fluid cytoplasm of laticifers, of Hevea brasiliensis. Although it has been found that natural rubber is biosynthesized through the mevalonate pathway, the involvement of an alternative 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway is uncertain. We obtained all series of the MEP pathway candidate genes by analyzing expressed sequence tag (EST) information and degenerate PCR in H. brasiliensis. Complementation experiments with Escherichia coli mutants were performed to confirm the functions of the MEP pathway gene products of H. brasiliensis together with those of Arabidopsis thaliana, and it was found that 1-deoxy-D-xylulose-5-phosphate reductoisomerase, 2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase, and 2-C-methyl-D-erythritol 2,4-cyclodiphosphate synthase of H. brasiliensis were functionally active in the E. coli mutants. Gene expression analysis revealed that the expression level of the HbDXS2 gene in latex was relatively high as compared to those of other MEP pathway genes. However, a feeding experiment with [1-13C] 1-deoxy-D-xylulose triacetate, an intermediate derivative of the MEP pathway, indicated that the MEP pathway is not involved in rubber biosynthesis, but is involved in carotenoids biosynthesis in H. brasiliensis.
    Download PDF (867K)
  • R. M. Udayangani RATNAYAKE, Hitoshi INOUE, Hiroshi NONAMI, Mitsuru AKI ...
    2008 Volume 72 Issue 11 Pages 2926-2935
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    During protein import into chloroplasts, one of the Hsp70 proteins in pea (Hsp70-IAP), previously reported to localize in the intermembrane space of chloroplasts, was found to interact with the translocating precursor protein but the gene for Hsp70-IAP has not been identified yet. In an attempt to identify the Arabidopsis homolog of Hsp70-IAP, we employed an in vitro protein import assay to determine the localization of three Arabidopsis Hsp70 homologs (AtHsp70-6 through 8), predicted for chloroplast targeting. AtHsp70-6 and AtHsp70-7 were imported into chloroplasts and processed into similar-sized mature forms. In addition, a smaller-sized processed form of AtHsp70-6 was observed. All the processed forms of both AtHsp70 proteins were localized in the stroma. Organelle-free processing assays revealed that the larger processed forms of both AtHsp70-6 and AtHsp70-7 were cleaved by stromal processing peptidase, whereas the smaller processed form of AtHsp70-6 was produced by an unspecified peptidase.
    Download PDF (391K)
  • Kosuke NAKAMURA, Masami INOUE, Takeo YOSHIIE, Katsutoshi HOSOI, Yoshin ...
    2008 Volume 72 Issue 11 Pages 2936-2945
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    In developing plants, free N-glycans occur ubiquitously at micromolar concentrations. Such oligosaccharides have been proposed to be signaling molecules in plant development. As a part of a study to elucidate the physiological roles of de-N-glycosylation machinery involved in fruit ripening, we analyzed changes in the amounts and structural features of free N-glycans in tomato fruits at four ripening stages. The amount of high-mannose type free N-glycans increased significantly in accordance with fruit ripening, and the relative amounts of high-molecular size N-glycans, such as Man8-9GlcNAc1, became predominant. These observations suggest that the de-N-glycosylation machinery, including endo-β-N-acetylglucosaminidase (ENGase) activity, is stimulated in the later stages of fruit ripening. But contrary to expectation, we found that total ENGase activities in the tomato fruits did not vary significantly with the ripening process, suggesting that ENGase activity must be maintained at a certain level, and that the expression of α-mannosidase involved in the clearance of free N-glycans decreases during tomato fruit ripening.
    Download PDF (262K)
  • Kazuhiro MACHIDA, Akira ARISAWA, Susumu TAKEDA, Toshio TSUCHIDA, Yasuh ...
    2008 Volume 72 Issue 11 Pages 2946-2952
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    Pladienolides are novel 12-membered macrolides produced by Streptomyces platensis Mer-11107. They show strong antitumor activity and are a potential lead in the search for novel antitumor agents. We sequenced the 65-kb region covering the biosynthetic gene cluster, and found four polyketide synthase genes (pldAI-pldAIV) composed of 11 modules, three genes involved in post-modifications (pldB-D), and a luxR-family regulatory gene (pldR). The thioesterase domain of pldAIV was more dissimilar to that of polyketide synthase systems synthesizing 12/14-membered macrolide polyketides than to that of systems synthesizing other cyclic polyketides. The pldB gene was identified as a 6-hydroxylase belonging to a cytochrome P450 of the CYP107 family. This was clarified by a disruption experiment on pldB, in which the disruptant produced 6-dehydroxy pladienolide B. Two genes located downstream of pldB, designated pldC and pldD, are thought to be a probable genes for 7-O-acetylase and 18, 19-epoxydase respectively.
    Download PDF (158K)
Biochemistry & Molecular Biology Notes
Biochemistry & Molecular Biology Communication
  • Yurika MIZOBE, Daichi OIKAWA, Shoichiro TSUYAMA, Yoriko AKIMOTO, Kousu ...
    2008 Volume 72 Issue 11 Pages 3067-3070
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    Elastic fibers in the dermis play an important role in skin elasticity. The desmosine crosslinking structure constructed of lysyl oxidase (LOX) in elastic fibers contributes to elasticity, while elastic fibers are primarily degraded by one of the matrix metalloproteinases (MMPs), MMP-12. We investigated the gender differences and diurnal variation of these enzymes. Gender-based differences in LOX mRNA expression were detected, and were significantly lower in females. In contrast, higher MMP-12 mRNA expression was observed in the light period, suggesting that elastic fibers might be degraded in the light rather than the dark period.
    Download PDF (74K)
Food & Nutrition Science Regular Papers
  • Sogo NISHIMOTO, Yoko GOTO, Hitoshi MORISHIGE, Ryusuke SHIRAISHI, Mikih ...
    2008 Volume 72 Issue 11 Pages 2806-2814
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    We have previously demonstrated that collagen from jellyfish simulated immunoglobulin and cytokine production by human-human hybridoma line HB4C5 cells and by human peripheral blood lymphocytes (hPBL). The mode of action of the collagen as an immunostimulatory factor was investigated. The expression levels of immunoglobulin mRNAs in HB4C5 cells, and those of tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and transforming growth factor (TGF)-β in hPBL were up-regulated by jellyfish collagen. In addition, this collagen activated IgM production by transcription-suppressed HB4C5 cells that had been treated with actinomycin D. This collagen also enhanced IgM production by translation-suppressed HB4C5 cells that had been treated with sodium fluoride, but was ineffective in accelerating IgM production by HB4C5 cells treated with cycloheximide. Moreover, the intracellular IgM level in HB4C5 cells treated with the post-translation inhibitor, monensin, was increased by this collagen. These results suggest that collagen from jellyfish stimulated not only the transcription activity, but also the translation activity for enhanced immunoglobulin and cytokine production.
    Download PDF (144K)
  • Sunmin PARK, Il Sung AHN, Dae Young KWON, Byoung Seob KO, Won Kyung JU ...
    2008 Volume 72 Issue 11 Pages 2815-2823
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    Ginseng root is known to induce anti-diabetic activity, but the key components involved are unknown. We investigated which major ginsenosides in ginseng enhanced glucose homeostasis by in vitro studies. Rb1 and Rg1 reduced the triglyceride accumulation in 3T3-L1 adipocytes by activating PKA with increased intracellular cAMP. However, the insulin-stimulated glucose uptake was enhanced by Rb1 and Rg1 via activation of phosphatidylinositol-3 kinase. Rb1 and Rg1 promoted glucose-stimulated insulin secretion and cell viability in Min6 cells through PKA which augmented IRS2 expression to enhance insulin/IGF-1 signaling. These results suggest that Rb1 and Rg1 improved glucose homeostasis through the activation of a PKA like glucagon-like peptide-1 receptor agonist.
    Download PDF (207K)
  • Kyoko TODA, Kazuhiro YAGASAKI, Koji TAKAHASHI
    2008 Volume 72 Issue 11 Pages 2824-2830
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    Many studies have suggested that the 11S/7S ratio in soybeans affects the coagulation reaction at the first step. In this study, the 11S/7S ratio in soybeans showed significantly negative correlation with MgCl2 concentrations for the maximum breaking stress of tofu for six Japanese varieties. To determine the effect of the 11S/7S ratio, soymilk was fractionated by centrifugation after the addition of MgCl2, and the distribution of lipids and proteins was studied. The amount of precipitate increased as the MgCl2 concentration or the 11S/7S ratio increased. More triglyceride was incorporated into the precipitate as the MgCl2 concentration or the 11S/7S ratio increased. The stain intensity of bands after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS–PAGE) indicated that the ratio of oleosin, a membrane protein of the oil body, increased in the precipitate as the MgCl2 concentration or the 11S/7S ratio increased, while the ratios of glycinin and β-conglycinin were less variable. These results indicate that the 11S/7S ratio and coagulant concentration may have an effect on the amount of coagulum and the concentration of oil globules in the coagulum at the beginning of coagulation.
    Download PDF (309K)
  • Hiroya KAWASAKI, Atsuko YAMADA, Ryota FUSE, Tohru FUSHIKI
    2008 Volume 72 Issue 11 Pages 2840-2846
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    We investigated how gustatory and olfactory information contributes to the preference for dried bonito broth in mice. In the two-bottle preference test, intact mice consumed dried bonito broth in preference to water or an amino acid-nucleotide (AN) solution containing the same concentration of amino acids and nucleotides as that in dried bonito broth. It was observed that mice with transected bilateral chorda tympani (CT) nerves, those with transected bilateral glossopharyngeal (GL) nerves, and those that were intranasally administered with zinc sulfate preferred dried bonito broth to water. Zinc sulfate was used to produce a temporary loss of olfaction. In the two-bottle preference test with dried bonito broth and an AN solution, the preference for the former was reduced in mice with transected bilateral GL nerves and in those with an olfactory blockade, but not in mice with transected bilateral CT nerves. These results suggest that dried bonito broth was preferred over the AN solution, and that simultaneous inputs from olfaction and the GL nerve contributed to this preference.
    Download PDF (137K)
  • Martin Patrick ONGOL, Takeshi IGUCHI, Michiko TANAKA, Teruo SONE, Hiro ...
    2008 Volume 72 Issue 11 Pages 2847-2857
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    Lactic acid bacteria (LAB) might switch the Th2 biased immune response in allergic patients towards a balanced Th1/Th2 immune profile, leading to amelioration of allergy. To select strains of LAB that could be of potential application for foods in controlling allergy, 35 bacterial strains were screened in vitro using murine splenocytes and peritoneal exudate cells (PECs). Streptococcus thermophilus AHU1838 (FERM AP-21009), and Lactobacillus paracasei subsp. casei AHU1839 (FERM AP-21010) enhanced the secretion of Th1 cytokines such as interferon-γ (IFN-γ) and interleukin-12 (IL-12). The two strains of LAB also up-regulated the expression of CD40, and CD86 in dendritic cells (DCs), and activated cytotoxic T lymphocytes (CTL). These two strains could therefore be used in producing fermented food products that can enhance the Th1 immune profile which is important in ameliorating allergy.
    Download PDF (285K)
  • Hiroyuki FUJISAWA, Kaoru SUMA, Kana ORIGUCHI, Taiichiro SEKI, Toyohiko ...
    2008 Volume 72 Issue 11 Pages 2877-2883
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    The garlic-derived antibacterial principle, alk(en)yl sulfinate compounds, has long been considered as very short-lived substance. However, there are some data showing a rather more stable nature of allicin. We determined here the thermostability of allicin by a systematic analyses employing chemical quantification and an antibacterial activity assay. Allicin in an aqueous extract of garlic was degraded stoichiometrically in proportion to the temperature; we estimated the half-life of allicin to be about a year at 4 °C (from 1.8 mg/ml to 0.9 mg/ml) and 32 d at 15 °C, but only 1 d at 37 °C (from 2.0 mg/ml to 1.0 mg/ml). The half-life values for antibacterial activity showed a similar trend in results: 63 d or more at 4 °C for both antibacterial activities, 14 d for anti-staphylococcal activity, and 26 d for anti-escherichia activity at 15 °C, but only 1.2 d and 1.9 d for the respective activities at 37 °C. Such antibacterial activities were attributable to the major allicin, allyl 2-propenylthiosulfinate. Surprisingly, the decline in the quantity of allicin was not accompanied by its degradation; instead, allicin became a larger molecule, ajoene, which was 3-times larger than allicin.
    Download PDF (259K)
  • Kyung-Ok PARK, Yoshiaki ITO, Takashi NAGASAWA, Myeong-Rak CHOI, Naoyuk ...
    2008 Volume 72 Issue 11 Pages 2918-2925
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    We investigated the effect of dietary Korean proso-millet protein concentrate (PMP) on glycemic responses, plasma lipid levels, and the plasma level and gene expression of adiponectin in obese type 2 diabetic mice under normal and high-fat feeding conditions. The findings were that the feeding of PMP clearly elevated plasma high-density lipoprotein cholesterol (HDL cholesterol) and adiponectin levels and brought about effective reduction in the levels of glucose and insulin in mice under high-fat diet conditions as compared with a control diet. Gene expression study revealed that the diet up-regulated expression of adiponectin and down-regulated tumor necrosis factor-α (TNF-α). Considering the central role of adiponectin and HDL cholesterol in improving and ameliorating type 2 diabetes, obesity, and cardiovascular disease, our findings imply that PMP may have potential for therapeutic intervention in type 2 diabetes.
    Download PDF (105K)
  • Naoki HARIKAI, Shin SAITO, Midori ABE, Kazunari KONDO, Kazumi KITTA, H ...
    2008 Volume 72 Issue 11 Pages 2953-2958
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    A new real-time PCR method using capturing oligo-immobilized PCR tubes is described. This method was used to detect specific genes for soybean and genetically modified (GM) soybean in food matrices. In a standard reaction using soybean genomic DNA and a capturing oligo for the lectin gene (Le1) immobilized on the tube, we examined the effects of such hybridization conditions as the location, length, and amount of the capturing oligo, and the incubation time and temperature. Under optimized conditions, the copy number of Le1 was determined in a concentration-dependent manner from soybean genomic DNA and soybean lysate (DNA 10–1000 ng, r=0.99; lysate 1–100%, r=0.99). The copy number of a Roundup Ready soybean (RRS) gene was also successfully detected in a concentration-dependent manner (1–100%, r=0.99) from GM soybean lysate, using PCR tubes with an immobilized capturing oligo for the transgene. Our data indicate that this is a rapid and simple method to determine specific genes for soybean and GM soybean in food matrices.
    Download PDF (109K)
  • Gongliang ZHANG, Haitao WU, Beiwei ZHU, Yasuaki SHIMOISHI, Yoshimasa N ...
    2008 Volume 72 Issue 11 Pages 2966-2972
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    Organosulfur compounds have been established to possess anticancer effects. To provide a better understanding of the biological function of dimethyl sulfides, dimethyl monosulfide (Me2S), dimethyl disulfide (Me2S2), dimethyl trisulfide (Me2S3) and dimethyl tetrasulfide (Me2S4) were used as experimental materials to investigate their effects on apoptosis induction in human leukemia Jurkat cells and HL-60 cells. Treatment with 20 μM dimethyl sulfides for 24 h decreased the viability of both cells. The cell viability-reducing effect of these sulfides was in the following order: Me2S4 ≈ Me2S3 > Me2S2 ≈ Me2S for Jurkat cells and Me2S4 > Me2S3 > Me2S2 ≈ Me2S for HL-60 cells. Me2S3 and Me2S4 significantly induced DNA fragmentation and caspase-3 activation. The addition of GSH or NAC completely suppressed the sulfide-induced apoptosis. Our results indicate that dimethyl sulfides with a larger number of sulfur atoms more strongly induced apoptosis in both human leukemia cells via ROS production and caspase-3 activation.
    Download PDF (149K)
  • Pongsak RATTANACHAIKUNSOPON, Parichat PHUMKHACHORN
    2008 Volume 72 Issue 11 Pages 2987-2991
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    Chives, a member of the Alliaceae family, have been used in food and medicine in Thailand for a long time. Diallyl sulfides (diallyl monosulfide, dially disulfide, diallyl trisulfide, and diallyl tetrasulfide) are believed to be responsible for the antimicrobial activity of plants in this family. In this study, chive oil was examined for its diallyl sulfide content and its antimicrobial activity against some strains of food-borne pathogenic bacteria. Chive oil had a very low concentration of diallyl monosulfide in comparison with the other diallyl sulfides. They inhibited all pathogenic bacteria used in this study with a different degree of inhibition. Chive oil was also shown to be able to inhibit Escherichia coli O157:H7 in a food model. This study is the first report describing not only the diallyl disulfide content of chive oil, but also its antimicrobial activity against food-borne pathogens in both a test tube and food model.
    Download PDF (75K)
Food & Nutrition Science Notes
Microbiology & Fermentation Technology Regular Papers
  • Qiang YAO, Ting-Ting SUN, Wei-Feng LIU, Guan-Jun CHEN
    2008 Volume 72 Issue 11 Pages 2799-2805
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    The coding sequence of a novel cellulolytic factor, swollenin, was isolated from the cellulolytic fungus Trichoderma pseudokoningii S38. The full-length swo2 gene encodes a protein of 494 amino acids with a calculated molecular mass of 51,393 Da, which includes a putative 22-amino-acid signal peptide. Sequence analysis revealed significant identity between isolated swollenin and that from Trichoderma reesei. The swollenin gene was further expressed and purified in T. reesei QM9414. The expressed swollenin protein was consequently purified by two-step ion exchange chromatography. The purified swollenin had subtle hydrolytic activities on xylan and yeast cell wall glucan, while no apparent activities on carboxymethy cellulose, cotton fiber, filter paper, or cellulose powder CF11 were observed. These results indicate that although swollenin maintains unidentified glycohydrolytic activities, it is inactive against β-1,4-glycosidic bonds in cellulose. Its exact role in lignocellulose hydrolysis calls for further analysis.
    Download PDF (294K)
  • Kunio YAMANE, Hideaki MAKI, Tsuyoshi NAKAYAMA, Toshiaki NAKAJIMA, Nobu ...
    2008 Volume 72 Issue 11 Pages 2831-2839
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    To understand microbial communities in petroleum crude oils, we precipitated DNA using high concentrations of 2,2,4-trimethylpentane (isooctane) and purified. Samples of DNA from five crude oils, (Middle East, 3; China, 1; and Japan, 1) were characterized based upon their 16S rRNA gene sequences after PCR amplification and the construction of clone libraries. We detected 48 eubacterial species, one cyanobacterium, and one archaeon in total. The microbial constituents were diverse in the DNA samples. Most of the bacteria affiliated with the sequences of the three oils from the Middle East comprised similar mesophilic species. Acinetobacter, Propionibacterium, Sphingobium and a Bacillales were common. In contrast, the bacterial communities in Japanese and Chinese samples were unique. Thermophilic Petrotoga-like bacteria (11%) and several anaerobic-thermophilic Clostridia- and Synergistetes-like bacteria (20%) were detected in the Chinese sample. Different thermophiles (12%) and Clostridia (2%) were detected in the Japanese sample.
    Download PDF (773K)
  • Yukifumi UESONO, Tomoyuki ARAKI, Akio TOH-E
    2008 Volume 72 Issue 11 Pages 2884-2894
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    Supplementary material
    High osmolarity and glucose deprivation cause rapid shutdowns of both actin polarization and translation initiation in yeast. Like these stresses, administration of local anesthetics and of antipsychotic phenothiazines caused similar responses. All these drugs have amphiphilic structures and formed emulsions and permeabilized the cell membrane, indicating that they have the same features as a surfactant. Consistently with this, surfactants induced responses similar to those of local anesthetics and phenothiazines. Benzethonium chloride, a cationic surfactant, showed a more potent shutdown activity than phenothiazines, whereas SDS, an anionic surfactant, transiently depolarized actin without inhibiting translation initiation, suggesting that a cationic charge in the amphiphile is important to the shutdown of both reactions. The clinical drugs and the cationic surfactants at low concentrations caused shutdown without membrane permeabilization, suggesting that these compounds and stresses activate shutdown, via perturbation rather than disruption of the cell membrane.
    Download PDF (413K)
  • Masaru WADA, Nowaki HIJIKATA, Ryo AOKI, Nobuchika TAKESUE, Atsushi YOK ...
    2008 Volume 72 Issue 11 Pages 2959-2965
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    We have reported increased glutamate production by a mutant of Corynebacterium glutamicum ATCC14067 (strain F172-8) with reduced H+-ATPase activity under biotin-limiting culture conditions (Aoki et al. Biosci. Biotechnol. Biochem., 69, 1466–1472 (2005)). In the present study, we examined valine production by an H+-ATPase-defective mutant of C. glutamicum. Using the double-crossover chromosome replacement technique, we constructed a newly defined H+-ATPase-defective mutant from ATCC13032. After transforming the new strain (A-1) with a C-terminal truncation of acetohydroxyacid synthase gene (ilvBN), valine production increased from 21.7 mM for the wild-type strain to 46.7 mM for the A-1 in shaking flask cultures with 555 mM glucose. Increased production of the valine intermediate acetoin was also observed in A-1, and was reduced by inserting acetohydroxyacid isomeroreductase gene (ilvC) into the ilvBN plasmid. After transformation with this new construct, valine production increased from 38.3 mM for the wild-type strain to 95.7 mM for A-1 strain. To the best of our knowledge, this is the first report indicating that an H+-ATPase-defective mutant of C. glutamicum is capable of valine production. Our combined results with glutamate and valine suggest that the H+-ATPase defect is also effective in the fermentative production of other practical compounds.
    Download PDF (108K)
  • Hirokazu SUZUKI, Kazuya MARUSHIMA, Yasuo OHNISHI, Sueharu HORINOUCHI
    2008 Volume 72 Issue 11 Pages 2973-2980
    Published: November 23, 2008
    Released: November 23, 2008
    [Advance publication] Released: November 07, 2008
    JOURNALS FREE ACCESS
    The linear chromosome of Streptomyces griseus IFO13350 contains not only atypical telomere sequences but also probable pseudogenes for two typical telomeric proteins. Two identical operons (SGR98t-SGR97t near one telomere and SGR7041t-SGR7042t near the other telomere) in the terminal inverted repeat sequence were predicted to encode a novel pair of telomeric proteins. SGR97t, a 185-amino-acid protein showing only 18% amino acid sequence identity to typical terminal proteins of Streptomyces, was found to be attached to the chromosomal ends, as determined by immunological analysis. On the other hand, electrophoretic mobility shift assays showed that SGR98t, an 837-amino-acid protein having a DnaB-like helicase C-terminal domain, was capable of binding specifically to the single-stranded terminal DNA corresponding to the 3′ overhang of the replication intermediate. These results indicate that SGR97t (and SGR7042t) and SGR98t (and SGR7041t) were the functional telomeric proteins in the replication of the linear chromosome of S. griseus IFO13350.
    Download PDF (443K)
Microbiology & Fermentation Technology Notes
feedback
Top