Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
Volume 69 , Issue 11
Showing 1-36 articles out of 36 articles from the selected issue
Review
  • Yosuke KOGA, Hiroyuki MORII
    2005 Volume 69 Issue 11 Pages 2019-2034
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    A great number of novel and unique chemical structures of archaeal polar lipids have been reported. Since 1993, when those lipids were reviewed in several review articles, a variety of core lipids and lipids with unique polar groups have been reported successively. We summarize new lipid structures from archaea elucidated after 1993. In addition to lipids from intact archaeal cells, more diverse structures of archaea-related lipids found in environmental samples are also reviewed. These lipids are assumed to be lipids from unidentified or ancient archaea or related organisms. In the second part of this paper, taxonomic and ecological aspects are discussed. Another aspect of archaeal lipid study has to do with its physiological significance, particularly the phase behavior and permeability of archaeal lipid membranes in relation to the thermophily of many archaea. In the last part of this review we discuss this problem.
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Analytical Chemistry Note
  • Yoshiaki NISHIYA, Yasuo YOSHIDA, Mamiko YOSHIMURA, Haruka FUKAMACHI, Y ...
    2005 Volume 69 Issue 11 Pages 2244-2246
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    We have developed a new enzymatic assay for determining L-cysteine concentration. The method involves the use of βC-S lyase from Streptococcus anginosus, which catalyzes the α,β-elimination of L-cysteine to hydrogen sulfide, pyruvate, and ammonia. The production of pyruvate is measured by D-lactate dehydrogenase and NADH. The decrease in NADH was proportional to the L-cysteine concentration up to 1.0 mM. When serum samples were used, within-day and day-to-day coefficient variations were below 4%. This method is simple, and can easily and reliably be used for accurate determination of L-cysteine concentration in serum or other samples.
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Organic Chemistry Regular Papers
  • Sanae KISHIMOTO, Takashi MAOKA, Katsuhiko SUMITOMO, Akemi OHMIYA
    2005 Volume 69 Issue 11 Pages 2122-2128
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    Nineteen carotenoids were identified in extracts of petals of orange- and yellow-flowered cultivars of calendula (Calendula officinalis L.). Ten carotenoids were unique to orange-flowered cultivars. The UV–vis absorption maxima of these ten carotenoids were at longer wavelengths than that of flavoxanthin, the main carotenoid of calendula petals, and it is clear that these carotenoids are responsible for the orange color of the petals. Six carotenoids had a cis structure at C-5 (C-5′), and it is conceivable that these (5Z)-carotenoids are enzymatically isomerized at C-5 in a pathway that diverges from the main carotenoid biosynthesis pathway. Among them, (5Z,9Z)-lycopene (1), (5Z,9Z,5′Z,9′Z)-lycopene (3), (5′Z)-γ-carotene (4), and (5′Z,9′Z)-rubixanthin (5) has never before been identified. Additionally, (5Z,9Z,5′Z)-lycopene (2) has been reported only as a synthesized compound.
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  • Mochammad Amin ALAMSJAH, Shotaro HIRAO, Fumito ISHIBASHI, Yuji FUJITA
    2005 Volume 69 Issue 11 Pages 2186-2192
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    Thirty-seven species of seaweeds including 10 Chlorophyta, 13 Phaeophyta, and 14 Rhodophyta collected from the coast of Nagasaki Prefecture, Japan, were screened for algicidal activity against the red-tide phytoplankton Heterosigma akashiwo. The green alga Ulva fasciata (Ulvaceae, Chlorophyta) showed the strongest algicidal activity among the seaweeds tested. Bioassay-guided fractionation of the methanol extract of U. fasciata led to isolation of three algicidal compounds whose structures were determined to be hexadeca-4,7,10,13-tetraenoic acid (HDTA), octadeca-6,9,12,15-tetraenoic acid (ODTA), and α-linolenic acid on the basis of spectroscopic information. These polyunsaturated fatty acids (PUFAs) showed potent algicidal activity against H. akashiwo (LC50 1.35 μg/ml, 0.83 μg/ml, and 1.13 μg/ml for HDTA, ODTA, and α-linolenic acid, respectively), and the result demonstrated the potential of these PUFAs for practical harmful algal bloom control.
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Biochemistry & Molecular Biology Regular Papers
  • Hiromi AMANO, Masashi YAMAGIWA, Tetsuyuki AKAO, Eiichi MIZUKI, Michio ...
    2005 Volume 69 Issue 11 Pages 2063-2072
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    Bacillus thuringiensis, the most successful and most widely used microbial insecticide, produces crystal proteins. The physiological significance of the crystal proteins is poorly understood except for the potent insecticidal activity. In this paper, we report a novel biological activity of the crystal protein. A 29-kDa crystal protein, p29, produced by B. thuringiensis subsp. coreanensis A1519, was toxic to Jurkat, a cell line from human leukemic T cells. Upon treatment of the Jurkat cells with p29 at a lower concentration, translocation of phosphatidylserine to the external cell surface, release of cytochrome c and Smac/DIABLO from the mitochondria, and activation of caspase-9 were induced. These cellular events were followed by activation of caspase-3, cleavage of poly (ADP-ribose) polymerase (PARP), and chromatin condensation. Peak activation of caspase-9 was prominent and preceded that of caspase-8. Depletion of Bax from the cytosol was observed as the progress of p29-induced cell death. At a higher concentration of p29, the cells showed similar and accelerated morphological change, but neither externalized phosphatidylserine nor caspase-3 activation was observed. These results suggest that p29 at the lower concentration induced cell death of Jurkat accompanied by apotosis-like cellular events, and that mitochondria played a major role in p29-induced cell death.
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  • Pingbo ZHANG, Kohji YAMAMOTO, Yoichi ASO, Yutaka BANNO, Daisuke SAKANO ...
    2005 Volume 69 Issue 11 Pages 2086-2093
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    It is recognized that P25 is one of three polypeptide components of the fibroin synthesized in the larval silk gland (SG) of silkworm, having two glycosylated isoforms. In the present study, however, eight P25 isoforms were separated by proteomics, including two-dimensional gel electrophoresis of whole SG proteins, and were identified by the peptide mass fingerprinting method. Four of the eight isoforms were identified as Bombyx mandarina P25s, although the SG of Bombyx mori has never been considered to contain the P25 from B. mandarina. It is suggested that this diversity of P25 isoforms depends on phosphorylation modification in addition to glycosylation.
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  • Yota TATARA, Takashi YOSHIDA, Eiji ICHISHIMA
    2005 Volume 69 Issue 11 Pages 2101-2108
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    Aspergillus saitoi 1,2-α-mannosidase contains three conserved cysteine residues (Cys334, Cys363, and Cys443). We showed that Cys334 and Cys363 are involved in a disulfide bond, and that Cys443 contains a free thiol group. The cysteines were not essential for the activity analyzed by site-directed mutagenesis and kinetics. The substitution at each cysteine residue greatly destabilized the enzyme. The Tm values of WT, C443A, C443G, C443S, and C443T were 55.8, 51.9, 50.2, 50.0, and 52.8 °C respectively. The specific activity of these mutants was almost equal to that of WT. Introducing Asp, Leu, Met, or Val at position 443 caused partial denaturation, although the enzymes had some activity. C443F, C443I, C443N, and C443Y were not secreted. These results suggest that the hydrophilic and large side chain causes the destabilization. Molecular modelling showed that the Cys443 residue is buried and surrounded by a hydrophobic environment. Cys334 and Cys363 form a disulfide bond, and Cys443 is involved in a hydrophobic interaction to stabilize the enzyme.
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  • Tomoko IWAKI, Yasuko FUJITA, Naotaka TANAKA, Yuko GIGA-HAMA, Kaoru TAK ...
    2005 Volume 69 Issue 11 Pages 2109-2116
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    A potential correlation between mitochondrial and vacuolar functions is known to exit in yeast. Fission yeast atm1+, SPAC15A10.01, encodes a putative half-type ABC transporter with an N-terminal mitochondrial-targeting signal. In an attempt to evaluate the possible involvement of mitochondrion in vacuole function, a functional analysis of atm1+ was performed by gene disruption. Growth of the atm1 mutant was inhibited in the presence of oxidizing agents, and S. cerevisiae Atm1p was found to complement this growth defect. atm1Δ cells exhibited defects in fluid-phase endocytosis and vacuolar fusion under hypotonic stress. GFP-tagged Atm1p was observed to be localized in the mitochondria. These data strongly suggest that fission yeast Atm1p was not only involved in protection against oxidative stress, but also played a role in vacuolar functions.
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  • Yeon-Hee HONG, Daisuke HISHIKAWA, Hisae MIYAHARA, Yukihiko NISHIMURA, ...
    2005 Volume 69 Issue 11 Pages 2117-2121
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    To investigate the role of claudin-6 in adipogenesis, claudin-6 mRNA was examined in adipose tissues and adipocyte differentiation. Claudin-6 mRNA was found to be differentially expressed in four different adipose tissues, and up-regulated in each fat depot of mice fed a high-fat diet as compared to a normal-fat diet. Levels of claudin-6 transcripts were increased during differentiation of 3T3-L1 cells in vitro. Moreover, small interfering RNA (siRNA)-mediated reduction of claudin-6 mRNA inhibited differentiation of 3T3-L1 cells. These results suggest that claudin-6 is another important regulator in adipogenesis and fat deposition.
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  • Tadao OIKAWA, Noriko YAMAMOTO, Koji SHIMOKE, Shinichi UESATO, Toshihik ...
    2005 Volume 69 Issue 11 Pages 2146-2154
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    We purified the psychrophilic and thermolabile malate dehydrogenase to homogeneity from a novel psychrotolerant, Flavobacterium frigidimaris KUC-1, isolated from Antarctic seawater. The enzyme was a homotetramer with a molecular weight of about 123 k and that of the subunit was about 32 k. The enzyme required NAD(P)+ as a coenzyme and catalyzed the oxidation of L-malate and the reduction of oxalacetate specifically. The reaction proceeded through an ordered bi–bi mechanism. The enzyme was highly susceptible to heat treatment, and the half-life time at 40 °C was estimated to be 3.0 min. The kcatKmM−1·s−1) values for L-malate and NAD+ at 30 °C were 289 and 2,790, respectively. The enzyme showed pro-R stereospecificity for hydrogen transfer at the C4 position of the nicotinamide moiety of the coenzyme. The enzyme contained 311 amino acid residues and much lower numbers of proline and arginine residues than other malate dehydrogenases.
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  • Masakuni SERIZAWA, Keisuke KODAMA, Hiroki YAMAMOTO, Kazuo KOBAYASHI, N ...
    2005 Volume 69 Issue 11 Pages 2155-2169
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    YvrGHb is a novel two-component system in Bacillus subtilis. The yvrG and yvrHb genes are considered to encode sensor kinase and response regulator respectively. We found that the YvrGHb system positively regulates the 7 transcriptional units (wprA, wapA-yxxG, dltABCDE, sunA, sunT-bdbA-yolJ-bdbB, yvrI-yvrHa, and sigX-rsiX), and negatively regulates the lytABC operon. wprA, wapA, lytB, and lytC encode the main cell surface proteins of B. subtilis. Furthermore, SigX [extracytoplasmic function sigma factor (ECF sigma factor)] relating to the cell surface homeostatic functions, was regulated by this system. The yvrGHb null mutant showed the unusual autolysis and higher susceptibility to the four kinds of antibiotics (aztreonam, cefepime, bacitracin, and fosfomycin). These results indicate that the YvrGHb system is important to maintain the overall state of the cell surface through transcriptional regulation.
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  • Md. Ashraful HAQUE, Toshihisa KOTAKE, Yoichi TSUMURAYA
    2005 Volume 69 Issue 11 Pages 2170-2177
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    A β-glucuronidase purified from a commercial pectolytic enzyme preparation of Aspergillus niger hydrolyzed about half of the 4-O-methyl-glucuronic acid (4-Me-GlcA) residues located at the nonreducing terminals of (1→6)-linked β-galactosyl side chains of the carbohydrate portion of a radish arabinogalactan-protein (AGP) modified by treatment with fungal α-L-arabinosidase. Digestion of the α-L-arabinosidase-treated AGP with exo-β-(1→3)-galactanase released, by exo-fission of β-(1→3)-galactosidic bonds in the backbone chains of the AGP, neutral β-(1→6)-galactooligosaccharides with various chain lengths and their acidic derivatives substituted at their nonreducing terminals with 4-Me-β-GlcA groups. In contrast, successive digestion of the α-L-arabinosidase-treated AGP with β-glucuronidase followed by exo-β-(1→3)-galactanase liberated much higher amounts of β-(1→6)-galactooligomers together with a small portion of short acidic oligomers, mainly 4-Me-β-GlcA-(1→6)-Gal and 4-Me-β-GlcA-(1→6)-β-Gal-(1→6)-Gal. These results indicate that β-glucuronidase acts upon 4-Me-β-GlcA residues in long (1→6)-linked β-galactosyl side chains of the AGP, whereas short acidic side chains survive the attack of the enzyme.
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  • Fatih IZGÜ, Demet ALTINBAY, Abdullah SERTKAYA
    2005 Volume 69 Issue 11 Pages 2200-2206
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    K5-type yeast killer toxin secreted by P. anomala NCYC 434 cells has a broad killing spectrum. Competitive inhibiton of killer activity showed that glucans, mainly the β-1,3 glucan, represent the primary toxin binding site within the cell wall of sensitive cells. Its hydrolytic activity on laminarin in an exo-like fashion revealed that the toxin exerts its killing effect by exo-β-1,3-glucanase activity. Its specific activity on laminarin was 120 U/mg, and the Michaelis constants Km and Vmax for laminarin hydrolysis were 0.25 mg/ml and 370 μmol/min/mg. The toxin exerted its cytocidal effect after 2 h contact with the target cells. Production of the toxin by the cells was induced only when they were grown in culture media rich in β-glucan sources, and the addition of glucose increased the specific production rate. The enzymic activity of the toxin was fully inhibited by Hg+2, but increased with some other metal ions, most of all by Pb+2.
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  • Takao SAITO, Hajime TAKAHASHI, Hideo DOKEN, Hideki KOYAMA, Yasuaki ARA ...
    2005 Volume 69 Issue 11 Pages 2207-2212
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    Stimulation of normal mouse neutrophils with phorbol 12-myristate 13-acetate resulted in an acceleration of chromatin condensation and phosphatidylserine externalization that was not associated with caspase-3 activation. Caspase-independent death was completely inhibited by GF109203X and SB202190, specific inhibitors for protein kinase C and p38 mitogen-activated protein kinase respectively. Activation of p38 mitogen-activated protein kinase was completely suppressed by GF109203X, indicating that this enzyme is regulated by protein kinase C. On the other hand, cell death was abolished in NADPH oxidase-deficient neutrophils lacking superoxide production. Of note, p38 mitogen-activated protein kinase was activated by phorbol 12-myristate 13-acetate in normal and myeloperoxidase-deficient neutrophils lacking production of HOCl, whereas no activation was observed in NADPH oxidase-deficient neutrophils. These results strongly suggest that activation of p38 mitogen-activated protein kinase is regulated by endogenously generated superoxide or its metabolites other than HOCl, a critical regulator of inducer-stimulated death of neutrophils.
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Biochemistry & Molecular Biology Notes
Biochemistry & Molecular Biology Communication
Food & Nutrition Science Regular Papers
  • Ryoji TAKATA, Reiko YAMAMOTO, Takaaki YANAI, Tomonori KONNO, Toshiyuki ...
    2005 Volume 69 Issue 11 Pages 2042-2050
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    The fruit juice of black currant was found to contain a polysaccharide-rich substance, which was designated cassis polysaccharide (CAPS), with macrophage-stimulating activity. Especially, its interleukin (IL)-1β-inducing activity was remarkably high, compared with other fruit juice preparations. CAPS was found to consist of rhamnose, mannose, arabinose, galactose, xylose, and glucose in a molar ratio of 11.3:0.9:54.1:29.8:2.0:1.9. CAPS turned out to be partitioned into a soluble component (CAPS-l.m.) and a precipitable component (CAPS-h.m.) with mean MWs of 80,000 and 600,000 respectively in 45% (v/v) ethanol solution. At least in vitro, CAPS-l.m. rather than CAPS-h.m. appeared to play an important role in macrophage activation. Oral administration of black currant juice and CAPS to Ehrlich carcinoma-bearing mice retarded the growth of the solid tumor by 45% and 51% respectively. CAPS administration had a stimulatory effect on the release of IL-2, IL-10, interferon-γ, and IL-4 from splenocytes in comparison with PBS treatment in tumor-bearing mice. The IL-4 level was, however, still lower than that exhibited by a group of normal mice. CAPS showed a certain cytotoxicity directly against tumor cells.
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  • María Susana RODRÍGUEZ, Liliana Elena ALBERTENGO
    2005 Volume 69 Issue 11 Pages 2057-2062
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    Chitosan, the N acetylated derivative of chitin, has an effect on the absorption of dietary lipids, but there is not enough scientific knowledge about the mechanism.
    To study the interaction between chitosan and oil, the action of this biopolymer has been evaluated through an experimental model of the stomach and duodenum tract, although the enzimatic activity had not been evaluated.
    We microscopically confirmed that chitosan in a hychloridic acid medium (pH 1.0–2.0) emulsified lipids and the emulsion was a water in oil in water type (w/o/w). When the pH value and speed of agitation were increased to mirror the duodenum medium conditions under which lipids are absorbed, the emulsion capacity was better with an increased number of droplets and the emulsion continued as the w/o/w type. At pH 6.2, chitosan precipitated and lipids were entrapped in the formed flocculus. The binding oil was quantitatively determined, and we also demonstrate that a larger oil quantity induced less retention, while the chitosan characteristics had no influence.
    These observations allow us to postulate that the interaction between chitosan and oil inhibited duodenal absorption and enhanced lipid excretion.
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  • Yuki SHINODA, Hajime KOMURA, Seiichi HOMMA, Masatsune MURATA
    2005 Volume 69 Issue 11 Pages 2129-2137
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    A model solution of orange juice was prepared and stored. Factors affecting browning and formation of such decomposition products as 3-hydroxy-2-pyrone (3OH2P), 5-hydroxymethylfurfural (HMF), furfural, 5-hydroxymaltol, and 2-furoic acid were examined. Ascorbic acid (AsA) was essential for browning, which was stimulated by amino acids and citric acid, and repressed by chelators and radical scavengers (RS). 3OH2P was derived from AsA. Its formation was stimulated by sugars and repressed by citric acid, chelating agents, and RS. HMF was derived from fructose. Furfural was derived from AsA, and its formation was stimulated by sugars and chelating agents and repressed by RS. 5-Hydroxymaltol and 2-furoic acid were derived from fructose and AsA respectively. We did not find any decomposition products showing the same formation pattern as the browning, but a furfural solution with added amino acids turned brown like the model orange juice solution. It might be an indicator for the browning of orange juice.
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  • Keiko ISHIDA-FUJII, Shingo GOTO, Ryu UEMURA, Keita YAMADA, Michikatsu ...
    2005 Volume 69 Issue 11 Pages 2193-2199
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    The isotope ratios of carbon, hydrogen, and oxygen of rectified alcohols were determined to distinguish their botanical and geographical origins by continuous flow-isotope ratio mass spectrometry (CF-IRMS). The 13C/12C and 18O/16O ratios of 27 fermented alcohols with known origins showed clusters derived from each botanical origin, viz. corn, sugarcane, wheat, and tapioca. C3 and C4 plants were easily distinguishable by the 13C/12C ratio. Sugarcane and corn are both C4 plants, and they showed small differences in isotope ratios. The combination plots of the D/H and 18O/16O ratios enabled us to designate the geographical origins of alcohol derived from the same kind of crop, such as Chinese or American corn. The chemically synthetic and fermented alcohols were clearly distinguished by D/H and 18O/16O ratios. Isotope ratios were useful for origin identification of alcohol. We plan to construct a database of alcohol isotope ratios to determine the origins of raw materials in alcohol.
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Food & Nutrition Science Notes
Microbiology & Fermentation Technology Regular Paper
  • Cong Ha NGUYEN, Ryoji TSURUMIZU, Tsutomu SATO, Michio TAKEUCHI
    2005 Volume 69 Issue 11 Pages 2035-2041
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    A study of Taka-amylase A of conidia from Aspergillus oryzae RIB40 was done. During the research, proteins from conidia and germinated conidia were analyzed using SDS–PAGE, 2-D gel electrophoresis, Western blot analysis, MALDI-TOF Mass spectrometry, and native-PAGE combined with activity staining of TAA. The results showed that TAA exists not only in germinated conidia but also in conidia. Some bands representing degraded products of TAA were detected. Conidia, which formed on starch (SCYA), glucose (DCYA), and glycerol (GCYA) plates, contained mature TAA. Only one active band of TAA was detected after native-PAGE activity staining. In addition, TAA activity was detected in cell extracts of conidia using 0.5 M acetate buffer, pH 5.2, as extraction buffer, but was not detected in whole conidia or cell debris. The results indicate that TAA exists in conidia in active form even when starch, glucose, or glycerol is used as carbon source. TAA might belong to a set of basal proteins inside conidia, which helps in imbibition and germination of conidia.
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  • Yutaro KUMAGAI, Takashi HIRASAWA, Kenshi HAYAKAWA, Kazuo NAGAI, Masaak ...
    2005 Volume 69 Issue 11 Pages 2051-2056
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    Corynebacterium glutamicum belongs to the mycolic acid-containing actinomycetes, which also include Mycobacterium, Nocardia, and Rhodococcus. The cells of this group possess a cell wall with a thick outer layer composed primarily of mycolic acid, which functions as a permeability barrier. To investigate the mechanism of mycolic acid-containing layer (mycolate layer) formation, we have developed a fluorescence microscopic technique detecting the mycolate layer in situ. The staining specificity of fluorescence-labeled phospholipid analogs was determined by simultaneous staining with the hydrophobic fluorescent dye Nile Red and peptidoglycan-staining fluorescence-conjugated vancomycin. We found that fluorescence-labeled phospholipid analogs preferentially stain the mycolate layer. Using this technique, we observed the effect of the anti-mycobacterial drug ethambutol on C. glutamicum mycolate-layer formation. Ethambutol interfered specifically with mycolate-layer formation on the division planes and cell poles, while the side-wall mycolate layer was not severely affected. This indicates that mycolate-layer formation occurs mainly on division planes and cell poles in C. glutamicum, where the peptidoglycan layer is actively synthesized.
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  • Atsunori NEGISHI, Tadashi MURAOKA, Terunobu MAEDA, Fumiaki TAKEUCHI, T ...
    2005 Volume 69 Issue 11 Pages 2073-2080
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    Growth of five strains of sulfur-oxidizing bacteria Acidithiobacillus thiooxidans, including strain NB1-3, was inhibited completely by 50 μM of sodium tungstate (Na2WO4). When the cells of NB1-3 were incubated in 0.1 M β-alanine–SO42− buffer (pH 3.0) with 100 μM Na2WO4 for 1 h, the amount of tungsten bound to the cells was 33 μg/mg protein. Approximately 10 times more tungsten was bound to the cells at pH 3.0 than at pH 7.0. The tungsten binding to NB1-3 cells was inhibited by oxyanions such as sodium molybdenum and ammonium vanadate. The activities of enzymes involved in elemental sulfur oxidation of NB1-3 cells such as sulfur oxidase, sulfur dioxygenase, and sulfite oxidase were strongly inhibited by Na2WO4. These results indicate that tungsten binds to NB1-3 cells and inhibits the sulfur oxidation enzyme system of the cells, and as a result, inhibits cell growth. When portland cement bars supplemented with 0.075% metal nickel and with 0.075% metal nickel and 0.075% calcium tungstate were exposed to the atmosphere of a sewage treatment plant containing 28 ppm of H2S for 2 years, the weight loss of the portland cement bar with metal nickel and calcium tungstate was much lower than the cement bar containing 0.075% metal nickel.
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  • Makiko SAKKA, Tetsuya KIMURA, Kunio OHMIYA, Kazuo SAKKA
    2005 Volume 69 Issue 11 Pages 2081-2085
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    Recently, we reported that refuse-derived fuel (RDF) pellets contain a relatively high number of viable bacterial cells and that these bacteria generate heat and hydrogen gas during fermentation under wet conditions. In this study we analyzed bacterial cell numbers of RDF samples manufactured with different concentrations of calcium hydroxide, which is usually added to waste materials for the prevention of rotting of food wastes and the acceleration of drying of solid wastes, and determined the amount of hydrogen gas produced by them under wet conditions. Furthermore, we analyzed microflora of the RDF samples before and during fermentation by denaturing gradient gel electrophoresis of 16S rDNA followed by sequencing. We found that the RDF samples contained various kinds of clostridia capable of producing hydrogen gas.
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  • Shota TANIMOTO, Hideyuki MATSUMOTO, Kazuyoshi FUJII, Ritsushi OHDOI, K ...
    2005 Volume 69 Issue 11 Pages 2094-2100
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    The Inactivation kinetics of α-glucosidase, glucoamylase, α-amylase, and acid carboxypeptidase in fresh sake using a continuous flow system for high-pressure carbonation were investigated. In addition, the effects of ethanol and sugar concentrations on inactivation of the enzymes in high-pressure carbonated sake were investigated. Among the enzymes investigated, α-glucosidase was the most stable and α-amylase was the most labile on inactivation under carbonation. The decimal reduction times (D values) of α-glucosidase, glucoamylase, α-amylase (extrapolated from the Z value), and acid carboxypeptidase were 29, 6, 2, and 5 min respectively at 45 °C. These values are lower than those subjected to heat treatment. On the carbonation treatment as well as the heat treatment, ethanol accelerated the inactivation of all four enzymes, but glucose depressed the inactivation of these enzymes, except for acid carboxypeptidase. These results suggest that this continuous flow system enabled effective inactivation of enzymes in fresh sake.
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  • SI SI HLA, Junji KUROKAWA, SURYANI, Tetsuya KIMURA, Kunio OHMIYA, Ka ...
    2005 Volume 69 Issue 11 Pages 2138-2145
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    The Clostridium stercorarium F-9 pel9A gene encodes a pectate lyase Pel9A consisting of 1,240 amino acids with a molecular weight of 135,171. The mature form of Pel9A is a modular enzyme composed of two family-9 catalytic modules of polysaccharide lyases, CM9-1 and CM9-2, in order from the N terminus. Pel9A showed an overall sequence similarity to the hypothetical pectate lyase PelX of Bacillus halodurans (sequence identity 53%), and CM9-2 showed moderate sequence similarities to some pectate lyases of family 9. Sequence identity between CM9-1 and CM9-2 was 21.3%. The full-length Pel9A lacking the N-terminal signal peptide was expressed, purified, and characterized. The enzyme required Ca2+ ion for its enzyme activity and showed high activity toward polygalacturonic acid but lower activity toward pectin, indicating that Pel9A is a pectate lyase. Immunological analysis using an antiserum raised against the purified enzyme indicated that Pel9A is constitutively synthesized by C. stercorarium F-9.
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  • Manabu WATANABE, Naomi SUMIDA, Koji YANAI, Takeshi MURAKAMI
    2005 Volume 69 Issue 11 Pages 2178-2185
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    We purified saponin hydrolases from Aspergillus oryzae PF1224 and Eupenicillium brefeldianum PF1226. It was confirmed that the enzymes from A. oryzae PF1224 (Sda1) and E. brefeldianum PF1226 (Sde1) are glycoproteins with molecular masses of 82 and 90 kDa respectively. The deduced amino acid sequences of each enzyme from the cloned genes (sda1 or sde1) showed approximately 50% homology with that of the saponin hydrolase Sdn1 from Neocosmospora vasinfecta var. vasinfecta PF1225 (DDBJ accession no. AB110615). When sda1 and sde1 were expressed in the host Trichoderma viride under the control of the cellobiohydrolase I gene promoter, recombinant proteins were secreted with molecular masses of 77 and 67 kDa respectively. These recombinant enzymes hydrolyzed soyasaponin I to soyasapogenol B and triose, and its substrate specificities for glycosides were similar to that of Sdn1, but the specific activities of these enzymes were lower than that of Sdn1.
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  • Yuko IMAMURA, Masashi YUKAWA, Ken-ichi KIMURA, Hidetoshi TAKAHASHI, Yo ...
    2005 Volume 69 Issue 11 Pages 2213-2218
    Published: 2005
    Released: November 23, 2005
    JOURNALS FREE ACCESS
    Fredericamycin A (FMA) is an antibiotic product of Streptomyces griseus that exhibits modest antitumor activity in vivo and in vitro, but, its functions in vivo are poorly understood. We identified this compound as an inducer of G1 arrest in the yeast, Saccharomyces cerevisiae. FMA exhibits an IC50 of 24 nM towards the growth of a disruptant of multi-drug resistance genes, W303-MLC30, and its cytotoxicity is a function of the time of exposure as well as drug dose. Addition of 0.8 μM of FMA caused aggregation of mitochondria within 10 min of incubation and the drug induced petites at high frequency after 4 h of incubation. rho cells were about 20 times more resistant to FMA than isogenic rho+ cells. Overexpression of topoisomerase I, a previously suggested target of the drug, did not alleviate the sensitivity of the cells to FMA or the aggregation of mitochondria. Our results suggest that mitochondria are the primary target site of FMA.
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Microbiology & Fermentation Technology Note
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