Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
Volume 77 , Issue 2
Showing 1-42 articles out of 42 articles from the selected issue
Analytical Chemistry Regular Paper
  • Akira NAKAJIMA, Yasuhiro SAKURAI, Emiko MATSUDA, Yukari MASUDA, Yoshik ...
    2013 Volume 77 Issue 2 Pages 324-331
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
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    The hydroxyl- and superoxide-radical-eliminating ability of water-soluble biosubstances was examined by ESR combined with the spin-trapping method, indicating a median inhibitory dose, IDh50 (mM) and idh50 (mg/mL) for the hydroxyl radical, and IDs50 (mM) and ids50 (mg/mL) for the superoxide radical. Both the 1/[IDh50 (mM)] and 1/[IDs50 (mM)] values of selected biosubstances were linearly related to the second-order rate constant, k2 (M−1 s−1), defined for the reaction between biosubstances and the radicals in a logarithmic presentation. The result indicates that IDh50 (mM) and IDs50 (mM) are suitable parameters for both types of radical-eliminating ability. The obtained results are depicted two-dimensionally, taking idh50 (mg/mL) as the abscissa and ids50 (mg/mL) as the ordinate in the ROS inhibitory diagram. The biosubstances tested were assigned to five separate areas characterized by their functional groups on the diagram. The obtained ROS inhibitory diagram indicates the possibility for screening appropriate antioxidants.
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Organic Chemistry Regular Papers
  • Masanobu SUZUKI, Naoto NISHIDA, Atsushi ISHIHARA, Hiromitsu NAKAJIMA
    2013 Volume 77 Issue 2 Pages 271-275
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
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    Five new 3-O-alkyl-4a,10a-dihydrofusarubins (26) were isolated from the culture filtrate of a strain of Fusarium sp. (Mj-2), together with the known metabolite, anhydrofusarubin (1). The structures of the new metabolites were elucidated by spectroscopic analyses to be 3-O-butyl, 3-O-3′-methylbutyl, 3-O-2′-methylbutyl and 3-O-2′-phenylethyl-4a,10a-dihydrofusarubin A, and an isomer of 3-O-2′-phenylethyl-4a,10a-dihydrofusarubin A. Their antifungal and antibacterial activities were evaluated together with a 3-O-methyl derivative (7) prepared from 3-O-butyl-4a,10a-dihydrofusarubin A (2), indicating that the size of the O-substituent at C-3 in the 4a,10a-dihydrofusarubins negatively affected the metabolites' antimicrobial activity.
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  • Seung Young LEE, Eunjung MOON, Sun Yeou KIM, Sang Un CHOI, Kang Ro LEE
    2013 Volume 77 Issue 2 Pages 276-280
    Published: February 23, 2013
    Released: February 23, 2013
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    A further phytochemical investigation of the rhizomes of Acorus gramineus afforded three new quinone derivatives (13), together with two known compounds (4 and 5). The identification and structural elucidation of these new compounds were based on 1D and 2D NMR (COSY, HMQC, HMBC and NOESY) and MS data. The absolute configurations were established on the basis of their circular dichroism (CD) data. To investigate the anti-neuroinflammatory effects of the isolated compounds (15), the nitric oxide (NO) production was evaluated in the lipopolysaccharide-activated microglia cell line, BV-2. Compounds (15) were also tested for their cytotoxicity against four human tumor cell lines (A549, SK-OV-3, SK-MEL-2, and HCT-15) in vitro by using the SRB assay.
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Organic Chemistry Note
Biochemistry & Molecular Biology Regular Papers
  • Yung-Ming CHANG, Chuan-Te TSAI, Chiun-Chuang Roger WANG, Yueh-Sheng CH ...
    2013 Volume 77 Issue 2 Pages 229-234
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
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    Angiotensin II (Ang II) is a risk factor for cardiovascular disease. We used a traditional Chinese medicine, alpinate oxyphyllae fructus (AOF), to evaluate its effect on Ang II-induced cardiac apoptosis and mitochondrial dysfunction. Ang II-treated H9c2 cells were administered AOF of 20–100 µg/mL concentrations. Ang II significantly increased TUNEL-positive nuclei in the H9c2 cells, effect was inhibited by AOF administration in both pre-treated and post-treated H9c2 cells. Caspases 9 and 3 activities were increased by Ang II and downregulated by AOF administration, especially in pre-treatment. AOF treatment reversed Ang II-induced mitochondria membrane potential instability in H9c2 cells as observed by JC-1 stain assay. Furthermore, pro-apoptotic proteins Bad and cytochrome c increased and decreased respectively under AOF administration. The levels of p-Bad anti-apoptotic protein were significantly increased after AOF treatment. This study indicates that mitochondrial dependent apoptosis induced by Ang II.
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  • Masahiko ONODERA, Rie YATSUNAMI, Wataru TSUKIMURA, Toshiaki FUKUI, Kao ...
    2013 Volume 77 Issue 2 Pages 281-288
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
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    Haloarcula japonica is an extremely halophilic archaeon that requires high concentrations of NaCl to grow. Recently the draft genome sequence of Ha. japonica was determined, and a gene encoding an α-amylase, malA, was identified. The deduced amino acid sequence of MalA, consisting of 663 amino acids, showed homology to α-amylase family enzymes. The sequence did not contain a secretion signal sequence, indicating that the protein is a cytoplasmic enzyme. Transcription of the malA gene was confirmed by reverse transcription (RT)-PCR, and the transcription start site was determined by a 5'-RACE experiment. The malA gene was cloned and expressed in Ha. japonica. The recombinant MalA was purified and characterized. MalA required a high concentration of NaCl for starch-hydrolyzing activity. It showed higher activity on soluble starch, amylose, and amylopectin, and lower activity on glycogen.
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  • Ji-Young RYU, Jiyoung SEO, Sunhwa PARK, Joong-Hoon AHN, Youhoon CHONG, ...
    2013 Volume 77 Issue 2 Pages 289-294
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
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    The isoeugenol monooxygenase (iem) gene from Pseudomonas nitroreducens Jin1, responsible for the conversion of isoeugenol to vanillin, was cloned and overexpressed in Escherichia coli. The purified Iem had a predicted molecular mass of 54 kDa. The Vmax, KM, and kcat values for it, using isoeugenol as substrate, were 4.2 µmol vanillin min−1 mg−1 of protein, 120 µM, and 3.8 s−1, respectively. Maximum substrate turnover for Iem occurred at 30 °C and pH 9.0. An 18Oxygen-labeling experiment revealed that oxidative cleavage of isoeugenol by Iem was catalyzed via a monooxygenation reaction, and that incorporation of the oxygen atom from O2 into vanillin was preferable to incorporation from water. While the catalytic activity of Iem, as prepared, did not require the addition of any organic or metal cofactor, ICP-MS analysis showed 0.7 mol of iron per mol of Iem. Moreover site-directed mutagenesis of Iem of four conserved histidine residues individually, His167, His218, His282, and His471, which appear to be involved in ligand bonding with Fe2+, resulted in a loss of activity. Enzyme activity was not appreciably influenced by preincubation of Iem with high concentrations of chelators, suggesting that iron is tightly bound. Iem has an iron-mediated mechanism that is widely spread among the three domains of life.
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  • Takayoshi TAGAMI, Yoshiyuki TANAKA, Haruhide MORI, Masayuki OKUYAMA, A ...
    2013 Volume 77 Issue 2 Pages 312-319
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
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    Acarbose is a pseudo-tetrasaccharide and one of the most effective inhibitors of glycoside hydrolases. Its derivatives, acarviosyl-maltooligosaccharides, which have longer maltooligosaccharide parts than the maltose unit of acarbose, were synthesized using a disproportionating enzyme partially purified from adzuki cotyledons. The enzyme was identified as a typical type-1 disproportionating enzyme (DPE1) by primary structure analysis. It produced six compounds from 100 mM acarbose and 7.5% (w/v) of maltotetraose-rich syrup. The masses of the six products were confirmed to accord with acarviosyl-maltooligosaccharides with the degrees of polymerization = 5–10 (AC5–AC10) by electrospray ionization mass spectrometry. 1H and 13C NMR spectra indicated that AC5–AC10 were α-acarviosyl-(1→4)-maltooligosaccharide, which have maltotriose-maltooctaose respectively in the maltooligosaccharide part. A predominance of AC7 in the products at the early stage of the reaction indicated that DPE1 catalyzes the transfer of the acarviosyl-glucose moiety from acarbose to the acceptors. ACn can be useful tools as new inhibitors of glycoside hydrolases.
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  • Noriko TSURUI-NISHIMURA, Thanh Quang NGUYEN, Tomonori KATSUYAMA, Tatsu ...
    2013 Volume 77 Issue 2 Pages 339-344
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
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    Supplementary material
    Drosophila imaginal discs are an excellent model system for studies of developmental plasticity. In imaginal discs, most cells adhere strictly to their specific identity, but some cells undergo transdetermination, a process wherein the determined identity switches to another disc-specific identity. In this study, we performed gain-of-function screening and identified a gene, CG17836/Xrp1, that induces ectopic antennae in the eye field upon overexpression at the early eye disc stage. An essential factor in the distalization process, Distalles, and its upstream regulators Wingless, Hedgehog, and Decapentaplegic, are ectopically induced by CG17836/Xrp1 overexpression in eye discs, and this provides molecular evidence of the formation of ectopic antennae. Further, forced expression of CG17836/Xrp1 induced severe cell-proliferation defects. These findings suggest that CG17836/Xrp1 is involved in the regulation of cell proliferation in eye discs and affects disc identity specification.
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  • Michio SUZUKI, Arisa SUGISAKA-NOBAYASHI, Toshihiro KOGURE, Hiromichi N ...
    2013 Volume 77 Issue 2 Pages 361-368
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
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    The organic matrices in the exoskeleton of the crayfish Procambarus clarkii are classified into three groups depending on solubility; acid soluble, acid insoluble-SDS/dithiothreitol (DTT) soluble, and acid insoluble-SDS/DTT insoluble fractions. In our previous studies, Casp-1 and -2 were identified in the acid soluble fraction, and CAP-1 and -2 were identified in the acid insoluble-SDS/DTT soluble fraction. In this study, acid insoluble-SDS/DTT insoluble materials were digested with proteases and the resulting peptides were purified and sequenced. Based on the sequences, a cDNA encoding this protein was cloned. The whole primary sequence of the matrix protein named strong chitin-binding protein-1 (SCBP-1), was deduced. SCBP-1 consisted of 155 amino acid residues and had a Rebers-Riddiford consensus sequence for chitin binding. A recombinant protein of SCBP-N corresponding to the N-terminal part of SCBP-1 showed no chitin-binding ability, while SCBP-C corresponding to the C-terminal part of SCBP-1, showed weak affinity to chitin. These results suggest that the primary sequence of SCBP-1 does not have strong chitin-binding ability. Therefore, SCBP-1 probably binds covalently to chitin through a particular residue contained in the peptide part that was not obtained by protease digestion.
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Biochemistry & Molecular Biology Notes
Biochemistry & Molecular Biology Communications
Food & Nutrition Science Regular Papers
  • Atul UPADHYAY, Jamnian CHOMPOO, Nozomi TAIRA, Masakazu FUKUTA, Shinkic ...
    2013 Volume 77 Issue 2 Pages 217-223
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
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    The beneficial effects of the phytochemical compounds in fruits and vegetables have been extrapolated mainly from in vitro studies or short-term dietary supplementation studies. Recent approaches using animal models of Caenorhabditis elegans are becoming quite popular, and in this regard the effects of Alpinia zerumbet leaf extract (ALP) on C. elegans lifespan were investigated under both normal and stress conditions. ALP significantly increased, mean lifespan by 22.6%, better than the positive control, resveratrol. Furthermore, both under thermal and oxidative stressed conditions, ALP increased the survival rate significantly better than quercetin. Further studies indicated that the significant longevity-extending effects of ALP on C. elegans can be attributed to its in vitro free-radical scavenging effects and its upregulation of stress-resistance proteins, including superoxide dismutase 3 (SOD-3) and heat-shock protein (HSP-16.2). These results suggest that phytochemical compounds in A. zerumbet have beneficial effects on the lifespan of C. elegans, and that they can be used as a source of dietary supplements for aging and age-related diseases.
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  • Zhongyuan ZHANG, Kiichiro TERUYA, Hiroshi ETO, Sanetaka SHIRAHATA
    2013 Volume 77 Issue 2 Pages 235-242
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
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    Fucoidan, a fucose-rich polysaccharide extracted from brown seaweed, has antitumor, anticoagulant, antiviral, anti-inflammatory, and antibacterial activities. Several studies have shown that a fucoidan treatment of cancer cells induced cytotoxicity and apoptosis and inhibited angiogenesis and invasion. We investigated in the present study the effect of low-molecular-weight fucoidan (LMWF) on apoptosis in estrogen receptor-negative MDA-MB-231 human breast cancer cells. The LMWF treatment of MDA-MB-231 cells was associated with the activation of caspases and mitochondrial dysfunction, including dissipation of the mitochondrial membrane potential (ΔΨm), alteration of Ca2+ homeostasis, cytochrome c release, and decreased expression of antiapoptotic Bcl-2 family proteins. Understanding the molecular events that mediated LMWF-induced MDA-MB-231 cell death will contribute to a more rational approach to cancer chemotherapy.
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  • Masaru OCHIAI, Saho SHIOMI, Shun USHIKUBO, Reiko INAI, Tatsuhiro MATSU ...
    2013 Volume 77 Issue 2 Pages 243-248
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
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    We investigated the protective effect of a hydrous ethanol extract of brown rice fermented with Aspergillus oryzae (ERF) which contained nucleobases and low fiber on the methotrexate (MTX)-induced gastrointestinal damage in rats. The rats were assigned to three groups: control (CON), MTX, and MTX-ERF. The rats in the CON and MTX groups were fed for 4 weeks on a basal diet, and those in the MTX-ERF group were fed on a 9.16% ERF-containing basal diet. The rats in the MTX and MTX-ERF groups were administered with MTX after 3 weeks. The survival rate and incidence rate of diarrhea were monitored over 1 week. On day 4 after the administration, half of the rats in each group were killed, and gastrointestinal samples were collected. Feeding with ERF improved the incidence rate of diarrhea, increased the protein content in small intestinal mucosa, and also apparently improved the survival rate. These results indicate that dietary ERF could protect against MTX-induced gastrointestinal damage.
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  • Takenobu OGAWA, Shuji ADACHI
    2013 Volume 77 Issue 2 Pages 249-252
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
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    The water sorption kinetics of dried pasta were measured in the 20–90 °C range in 1.83 mol/L of NaCl and at 80 °C in 1.83 mol/L of LiCl, KCl, NaBr and NaI solutions in order to elucidate the role of salt in the kinetics. At the temperatures higher than 70.8 °C, the change in the enthalpy of sorption, ΔH, in the 1.83 mol/L NaCl solution was 33.1 kJ/mol, which was greater than the ΔH value in water, and the activation energy for the sorption, E, in the salt solution was 25.6 kJ/mol, which was slightly lower than the E value in water. The Hofmeister series of ions was an index for their effect on the equilibrium amount of the sorbed solution of pasta. The apparent diffusion coefficient of water into pasta was not correlated with the crystal radius of the salts, but was with the Stokes radius of the hydrated ions. Equations were formulated to predict the amount of sorbed solution under any condition of temperature and NaCl concentration.
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  • Ryoo TANIGUCHI, Osamu NAKAGAWASAI, Koichi TAN-NO, Fumihiro YAMADERA, W ...
    2013 Volume 77 Issue 2 Pages 266-270
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
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    The populations of the Kii Peninsula in Japan and of Guam present high incidences of amyotrophic lateral sclerosis and Parkinsonism-dementia complex. It is thought that low levels of calcium (Ca) and magnesium (Mg) in the drinking water are involved in the pathogenesis of these diseases. The present study aimed to test the hypothesis that catalepsy, behavioral immobility and a Parkinsonian symptom results from functionally impaired dopaminergic neurons in mice fed low amounts of Ca and Mg (LCa/Mg). A group of mice fed a LCa/Mg diet for 6 weeks was compared to a control group on a standard diet. Cataleptic symptoms such as akinesia and rigidity were measured by the bar test. The anti-parkinsonian drugs dopamine (DA) precursor L-3,4-dihydroxy phenylamine (L-DOPA), the selective DA receptor D2 agonist bromocriptine, and the DA releaser amantadine were tested for their effects on induced catalepsy. The mice developed catalepsy after 3 weeks on the LCa/Mg diet. LCa/Mg diet-induced catalepsy was improved by the administration of L-DOPA (50–200 mg/kg i.p.) in combination with benserazide (25 mg/kg i.p.), or of bromocriptine (0.25–4 mg/kg i.p.) or of amantadine (5–20 mg/kg i.p.). Immunohistochemical staining revealed that the intensity of tyrosine hydroxylase fluorescence was significantly decreased in the substantia nigra at the 6th week of LCa/Mg feeding in comparison with pair-fed controls. These results suggest that catalepsy in LCa/Mg mice results from hypofunction of the dopaminergic neurons. Moreover, our results support the hypothesis that LCa/Mg intake is one etiological factor in neurodegenerative disorders, including Parkinson's disease.
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  • Katsumi SHIBATA, Rina KONDO, Mitsue SANO, Tsutomu FUKUWATARI
    2013 Volume 77 Issue 2 Pages 295-300
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
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    Valproic acid (VPA) is a short-chained, branched fatty acid that is widely used in humans as an anticonvulsant and mood stabilizer, and has been reported to increase the liver NAD concentration. We investigated the effects of VPA on the conversion of tryptophan to nicotinamide. Rats were fed diets containing various amounts of VPA (0, 0.5, and 1.0% in the diets) for 14 d, 24-h urine samples were collected, and tryptophan and its catabolites were measured. We found that the conversion of tryptophan to nicotinamide was increased by feeding a diet containing VPA (p<0.01; 0% vs. 1.0% VPA). Of the intermediates formed during the conversion of tryptophan to nicotinamide, the tryptophan to 3-hydroxyanthranilic acid step was not affected by the administration of VPA, while such metabolites beyond quinolinic acid as nicotinamide and its catabolites were significantly increased (p<0.01; 0% vs. 1.0% VPA). This increase was dependent on the intake of VPA.
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  • Yonghae SON, Jeong-Su NAM, Min-Kyung JANG, In-Ah JUNG, Su-In CHO, Myeo ...
    2013 Volume 77 Issue 2 Pages 332-338
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
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    In this study, we evaluated the antiobesity effects of Vigna nakashimae (VN) extract and elucidated the underlying mechanisms. VN extract suppressed adipocyte differentiation and significantly attenuated the expression of adipogenic genes in 3T3-L1 cells. It decreased the expression of peroxisome proliferator-activated receptor γ (PPARγ) and its target genes in fully differentiated 3T3-L1 cells. Moreover, it enhanced the phosphorylation of AMP-activated protein kinase (AMPK) and acetyl CoA carboxylase (ACC), and increased the expression of fatty acid oxidation genes. In high-fat diet (HFD) fed mice, VN extract suppressed HFD-induced increases in body weight, epididymal fat tissue weight, and hepatic lipid levels, and decreased the plasma levels of triacylglycerols, fatty acid, total cholesterol, and inflammatory cytokines. Consistently with in vitro study results, VN extract prevented HFD-induced increases in the expression of PPARγ and its target genes, and restored the decrease in the phosphorylation of AMPK and ACC in epididymal fat and liver tissues. These findings suggest that Vigna nakashimae prevents obesity through suppression of PPARγ expression and activation of AMPK, and that it might be a useful dietary supplement for the prevention of obesity.
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Food & Nutrition Science Notes
Microbiology & Fermentation Technology Regular Papers
  • Youji NAKAGAWA, Junya SEITA, Shohei KOMIYAMA, Hideki YAMAMURA, Masayuk ...
    2013 Volume 77 Issue 2 Pages 224-228
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
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    Tolerance of microorganisms to diverse stresses (i.e., multistress tolerance) is a very useful property with industrial applications. We have developed a simple method for isolating multistress-tolerant semidominant mutants of the budding yeast Saccharomyces cerevisiae by one-step selection under lethal hydrogen peroxide (H2O2) stress condition, which we named the lethal concentration of H2O2 (LCH) method. This method involves simply isolating colonies after plating of mutagenized S. cerevisiae cells, which are cultivated overnight in liquid media, on agar plates containing a lethal concentration of H2O2 for the wild-type strain. Phenotypic and genetic analyses of the ten strains isolated by this method revealed that two strains exhibiting stress tolerance to H2O2, ethanol, heat shock, salt, organic solvent, freeze-thaw, chronological aging, and high concentrations of glucose possess semidominant and distinct single-gene mutations designated as MLT1-1 (multistress tolerance) and MLT2-1, which are responsible for multistress tolerance. From these results, we expect this method to confer multistress tolerance on industrial yeasts.
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  • Kenji MORIMOTO, Tsuyoshi SHIMONISHI, Seiki MIYAKE, Goro TAKATA, Ken IZ ...
    2013 Volume 77 Issue 2 Pages 253-258
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
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    When an M31 strain of Agrobacterium tumefaciens was grown in a mineral salt medium at 30 °C containing 1.0% lactitol as sole carbon source, a keto-sugar was efficiently accumulated in the supernatant. This oxidation from lactitol to the keto-sugar was caused by M31 cells grown with medium containing a disaccharide unit, including sucrose, lactitol, lactose, maltose, or maltitol, suggesting that the enzyme is inducible. M31 also demonstrated good growth characteristics in Tryptic Soy Broth (TSB) medium containing 1.0% sucrose, and cells grown under these conditions showed strong lactitol transformation activity. The keto-sugar product was reduced by chemical hydrogenation and the resulting product was hydrolyzed to D-gulose, D-galactose, and D-sorbitol by acid hydrolysis, revealing that the reduced products are lactitol and D-gulosyl-(β-1,4)-D-sorbitol. Taken together, these results indicate that M31 can convert lactitol to 3-ketolactitol and thus provide access to the rare sugar D-gulose.
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  • Chanikul CHUTRAKUL, Pratoomporn KHAOKHAJORN, Patchanee AUNCHAROEN, Tan ...
    2013 Volume 77 Issue 2 Pages 259-265
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
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    Severe chili anthracnose disease in Thailand is caused by Colletotrichum gloeosporioides and C. capsici. To discover anti-anthracnose substances we developed an efficient dual-fluorescent labeling bioassay based on a microdilution approach. Indicator strains used in the assay were constructed by integrating synthetic green fluorescent protein (sGFP) and Discosoma sp. red fluorescent protein (DsRedExp) genes into the genomes of C. gloeosporioides or C. capsici respectively. Survival of co-spore cultures in the presence of inhibitors was determined by the expression levels of these fluorescent proteins. This developed assay has high potential for utilization in the investigation of selective inhibition activity to either one of the pathogens as well as the broad-range inhibitory effect against both pathogens. The value of using the dual-fluorescent assay is rapid, reliable, and consistent identification of anti-anthracnose agents. Most of all, the assay enables the identification of specific inhibitors under the co-cultivation condition.
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  • Akihisa KITA, Yuki IWASAKI, Shinichi YANO, Yutaka NAKASHIMADA, Tamotsu ...
    2013 Volume 77 Issue 2 Pages 301-306
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
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    The application of microbial catalysts to syngas from the gasification of lignocellulosic biomass is gaining interest. Acetogens, a group of anaerobic bacteria, can grow autotrophically on gaseous substrates such as hydrogen and carbon dioxide or syngas and produce acetate via the acetyl-CoA pathway. Here, we report the isolation from a soil sample of two thermophilic acetogen strains, Y72 and Y73, that are closely related to Moorella sp. HUC22-1 and M. thermoacetica ATCC39073. The optimal growth temperature and pH for the strains were 60 °C and 6.0–6.5. Uracil auxotrophy was induced in them by replacing the orotate monophosphate decarboxylase gene (pyrF) with the kanamycin resistant marker (kanr). The transformants were isolated by supplementation of the basal medium with 300 mg/L of kanamycin. The transformation efficiency of strains Y72 and Y73 was 20-fold higher than that of strain ATCC39073. Hence these strains are considered possible hosts for thermophilic syngas fermentation.
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  • Junsung KIM, Sei-Heon JANG, ChangWoo LEE
    2013 Volume 77 Issue 2 Pages 320-323
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
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    A gene encoding a novel organic solvent-tolerant alkaline lipase, lipS (GenBank ID JQ071496), was cloned from cold-adapted Pseudomonas mandelii. Recombinant LipS was expressed in Escherichia coli as a 32-kDa soluble protein and was purified by standard procedures. It maintained more than 80% of its activity under alkaline conditions, pH 8–10.5, with an apparent optimum temperature range of 40–50 °C. It maintained thermal stability from 4 to 50 °C. After 1 h of incubation at 60 °C, approximately 50% of its activity remained. It retained its activity in organic solvents, and activity increased in the presence of ethanol and of DMSO. Our data indicate that LipS is an alkaline lipase with relatively high thermal stability and notable tolerance of organic solvents.
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  • Tatsuya FUNAHASHI, Tomotaka TANABE, Katsushiro MIYAMOTO, Hiroshi TSUJI ...
    2013 Volume 77 Issue 2 Pages 353-360
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
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    Aeromonas hydrophila ATCC 7966T produces a catecholate siderophore amonabactin in response to iron starvation. In this study, we determined that this strain utilizes exogenously supplied enterobactin (Ent) for growth under iron-limiting conditions. A homology search of the A. hydrophila ATCC 7966T genomic sequence revealed the existence of a candidate gene encoding a protein homologous to Vibrio parahaemolyticus IrgA that functions as the outer membrane receptor for ferric Ent. SDS–PAGE showed induction of IrgA under iron-limiting conditions. The growth of the double mutant of irgA and entA (one of the amonabactin biosynthetic genes) was restored when it was complemented with irgA in the presence of Ent. Moreover, a growth assay of three isogenic tonB mutants indicated that the tonB2 system exclusively provides energy for IrgA to transport ferric Ent. Finally, reverse transcriptase-quantitative PCR revealed that the transcription of irgA and the TonB2 system cluster genes is iron-regulated, consistently with the presence of a predicted Fur box in the promoter region.
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  • Makusu TSUIZAKI, Akinori OHTA, Hiroyuki HORIUCHI
    2013 Volume 77 Issue 2 Pages 369-374
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
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    Chitin is a major cell wall component of many filamentous fungi. Among the eight chitin synthase genes of Aspergillus nidulans, csmA and csmB encode a myosin motor-like domain (MMD) and a chitin synthase domain (CSD) at their N- and C-termini respectively. In our previous reports, we suggested that CsmA and CsmB play compensatory roles essential for polarized hyphal growth although their functions do not completely overlap, and that their MMDs are essential for their functions. In the present study, we constructed chimeric csm genes by swapping N-terminal MMD-encoding halves of csmA and csmB and studied them to identify functional differences in the MMDs. Expression of the chimeric gene encoding the MMD-including half of CsmA (MA) and the CSD-including half of CsmB thoroughly suppressed the phenotypic defects of the ΔcsmB mutant, whereas the chimeric gene encoding the MMD-including half of CsmB (MB) and the CSD-including half of CsmA did not fully suppress the defects of the ΔcsmA mutant, suggesting that MA suffices for the function of MB while MB is not functionally equivalent to MA.
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Microbiology & Fermentation Technology Notes
Environmental Science Regular Papers
  • Azuha YANO, Shi-Ping CHEN, Kazuko KITA, Xia JIANG, Qian REN, Tetsuo SA ...
    2013 Volume 77 Issue 2 Pages 307-311
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
    JOURNALS FREE ACCESS
    Annexin II, an HSP27-interacting protein, is involved in the protection of human cells against UVC. UVB is concerned with deleterious actions on human health. In this study, we attempted to confirm the anti-UVB effect of annexin II, and to elucidate the mechanisms underlying annexin II-involving UV resistance. The RSa cells were more sensitive to UVB lethality than the APr-1 cells. Overproduction of annexin II in RSa cells resulted in increased resistance to UVB lethality, while annexin II siRNA-transfected APr-1 cells were sensitized to UVB lethality. The excision capacity of the two major types (CPD and 6-4PP) of UVC- and UVB-damaged DNA in APr-1 cells was greater than in RSa cells. The excision capacity of the RSa cells improved following upregulation of annexin II, while the capacity of the APr-1 cells decreased after annexin II downregulation. Our results suggest that annexin II is involved in the UV resistance of human cells, via functioning in nucleotide excision repair.
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  • Yanan ZOU, Daekyung KIM, Motoaki YAGI, Yasuhiro YAMASAKI, Jun KURITA, ...
    2013 Volume 77 Issue 2 Pages 345-352
    Published: February 23, 2013
    Released: February 23, 2013
    [Advance publication] Released: February 07, 2013
    JOURNALS FREE ACCESS
    Lactate dehydrogenase (LDH)-release assay was applied to estimate the toxic potential of harmful algal species at the cellular level. African green monkey kidney (Vero), yellowtail fin epithelia (MJF), and rainbow trout gill (RTgill-W1) cells were used as target cells. A live cell suspension of Karenia mikimotoi (SUO-1) induced the release of LDH from these cell lines, while the activity of another strain, FUK, was much lower. The cell-free culture supernatants and ruptured cell suspensions of both strains of K. mikimotoi were less effective on LDH-release assay. Exposure experiments against abalone and shrimp revealed that SUO-1 showed much stronger lethal effects on these organisms than FUK. Among six phytoplankton species, three species known to be harmful algal species induced the release of LDH to different extents depending on the cell line, whereas the other three species, known to be non-toxic, showed no effects on any cell lines. These results suggest that LDH-release assay is a useful micro-plate assay for estimation of the toxic potential of harmful phytoplankton.
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