Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
Volume 76 , Issue 8
Showing 1-35 articles out of 35 articles from the selected issue
Organic Chemistry Regular Paper
  • Fumitada TSUJI, Ayako ISHIHARA, Aya NAKAGAWA, Masahiro OKADA, Shigeyuk ...
    2012 Volume 76 Issue 8 Pages 1492-1496
    Published: August 23, 2012
    Released: August 23, 2012
    [Advance publication] Released: August 07, 2012
    JOURNALS FREE ACCESS
    Supplementary material
    ComX, an oligopeptide pheromone that stimulates the natural genetic competence controlled by quorum sensing in Bacillus subtilis and related bacilli, contains a prenyl-modified tryptophan residue. Since ComX is the only protein known to contain prenylated tryptophan, the universality of this unique posttranslational modification has yet to be determined. Recently, we developed a cell-free assay system in which the tryptophan residue in the ComXRO-E-2 pheromone precursor derived from B. subtilis strain RO-E-2 can be geranylated by the ComQRO-E-2 enzyme. We report here our attempt to identify the consensus sequence surrounding the geranylated tryptophan residue by using the cell-free system with various ComXRO-E-2 pheromone precursor analogs. We found that [47–58]ComXRO-E-2, corresponding to the C-terminal 12-residue peptide of the pheromone precursor, contained a short sequence essential for geranylation. We also found that the length of the sequence between the tryptophan residue and the C-terminus was important for geranylation, and that some [47–58]ComXRO-E-2 pheromone precursor amino acids were involved in the geranylation reaction. However, we could not identify a consensus sequence surrounding the geranylated tryptophan. Our evidence suggests that, like Rab which lacks a consensus sequence yet is geranylgeranyl-modified on a cysteine residue, the ComX pheromone and its precursor also lack a consensus sequence.
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Organic Chemistry Notes
Biochemistry & Molecular Biology Regular Papers
  • Yukihiro ASAMI, Jae-Hyuk JANG, Hyuncheol OH, Jae Hak SOHN, Jong Won KI ...
    2012 Volume 76 Issue 8 Pages 1431-1437
    Published: August 23, 2012
    Released: August 23, 2012
    [Advance publication] Released: August 07, 2012
    JOURNALS FREE ACCESS
    Supplementary material
    Violaceol-I and -II were isolated from a fractionated library of marine-derived fungal metabolites. These compounds increased the calcium ion concentration inside the cell and caused F-actin aggregation in rat fibroblast 3Y1 cells within 3 h resulting in cell shape elongation. Calcium chelator BAPTA-AM (1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis (acetoxymethyl ester) inhibited violaceol-I and -II induced F-actin aggregation in 3Y1 cells, and hence violaceol-I and -II act in a calcium dependent manner. Violaceol-I and -II inhibited G-actin polymerization in vitro in a dose-dependent manner and strongly associated with G-actin, at dissociation equilibrium constants of 1.44 × 10−8 M and 2.52 × 10−9 M respectively. Here we report the identification of a novel function of violaceol-I and -II as actin inhibitors. Violaceol-I and -II induced cell shape elongation through F-actin aggregation in 3Y1 fibroblasts. These compounds may give researchers new insights into the role of actin in tumorigenesis and lead to the development of additional anti-tumor drugs.
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  • Maizom HASSAN, Nur Diyana MAAROF, Zainon Mohd ALI, Normah Mohd NOOR, R ...
    2012 Volume 76 Issue 8 Pages 1463-1470
    Published: August 23, 2012
    Released: August 23, 2012
    [Advance publication] Released: August 07, 2012
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    NADP+-dependent geraniol dehydrogenase (EC 1.1.1.183) is an enzyme that catalyzes the oxidation of geraniol to geranial. Stable, highly active cell-free extract was obtained from Polygonum minus leaves using polyvinylpolypyrrolidone, Amberlite XAD-4, glycerol, 2-mercaptoethanol, thiourea, and phenylmethylsulfonylfluoride in tricine-NaOH buffer (pH 7.5). The enzyme preparation was separated into two activity peaks, geraniol-DH I and II, by DEAE-Toyopearl 650M column chromatography at pH 7.5. Both isoenzymes were purified to homogeneity in three chromatographic steps. The geraniol-DH isoenzymes were similar in molecular mass, optimal temperature, and pH, but the isoelectric point, substrate specificity, and kinetic parameters were different. The Km values for geraniol of geraniol-DH I and II appeared to be 0.4 mM and 0.185 mM respectively. P. minus geraniol-DHs are unusual among geraniol-DHs in view of their thermal stability and optimal temperatures, and also their high specificity for allylic alcohols and NADP+.
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  • Fusheng CHI, Da FU, Xiaoping ZHANG, Zhongwei LV, Zhesheng WANG
    2012 Volume 76 Issue 8 Pages 1471-1476
    Published: August 23, 2012
    Released: August 23, 2012
    JOURNALS FREE ACCESS
    The hepatocyte growth factor receptor c-Met, a receptor tyrosine kinase, and Integrin α5β1, one of the main ECM receptors of hepatocytes have been reported to play important roles in tumor growth by activating mitogenic signaling pathways. In human gastric cardia adenocarcinoma, however, expression of the c-Met and Integrin α5β1 have not been reported. Here we examined the mRNA levels and protein expressions of these two genes and their relationship in human normal gastric cardia mucosa and primary carcinomas. Quantitative real-time PCR was used to analyze the mRNA expression of both c-Met and Integrin α5β1. The relationship between c-Met and Integrin α5β1 expression and the histologic characteristics of tumors were studied. Western blot analysis was performed to investigate the presence of c-Met and Integrin α5β1. The expression patterns of c-Met and Integrin α5β1 in 45 frozen slides of cardia adenocarcinoma were identified by immunohistochemistry. Our results indicate that the expression of c-Met and of Integrin α5β1 was significantly associated with tumor differentiation, TNM, and metastasis via the lymphogenic route. A significant positive correlation was also found between c-Met and Integrin α5β1 mRNA expression, suggesting that expression of c-Met and Integrin α5β1 has mechanical significance in the early stages of human gastric cardia adenocarcinoma.
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  • Hiroaki KATO, Satoru WATANABE, Kaori NIMURA-MATSUNE, Taku CHIBAZAKURA, ...
    2012 Volume 76 Issue 8 Pages 1484-1491
    Published: August 23, 2012
    Released: August 23, 2012
    [Advance publication] Released: August 07, 2012
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    Supplementary material
    To understand the induction of the adaptive response under various stress conditions, it is important to determine the partnership between histidine kinase and response regulators in the bacterial two-component system (TCS). The genes encoding TCS partners are usually comprised of an operon in the genome, but many of them are orphans in the cyanobacterial genome. There is little information on their partnerships in Synechococcus elongatus PCC 7942. Our comprehensive analysis of protein-protein interactions among all 37 full-length proteins and the truncated domains of 24 orphans revealed a number of specific interactions. They involved evolutionarily well-conserved orphan proteins among cyanobacterial species such as Synpcc7942_0453/Ycf29, NblS/RpaB, NblS/SrrA, SasA/RpaA, and SasA/Synpcc7942_2466. Our investigation of the transphosphorylation of interaction partners indicates that orphan TCSs comprise a complex signaling network.
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  • Katsuaki HIRANO, Sitthinan ARAYAVEERASID, Kiyohiko SEKI, David J. ADAM ...
    2012 Volume 76 Issue 8 Pages 1523-1528
    Published: August 23, 2012
    Released: August 23, 2012
    [Advance publication] Released: August 07, 2012
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    Chitosanase II was purified from the culture filtrate of Aspergillus fumigatus ATCC13073. The purified enzyme had a molecular mass of 23.5 kDa. The N-terminal amino acid sequence of chitosanase II was identical to those of other Aspergillus chitosanases belonging to glycoside hydrolase family 75. The optimum pH and temperature were pH 6.0 and 40 °C. Chitosanase II hydrolyzed 70% deacetylated chitosan faster than fully deacetylated chitosan. Analysis of the degradation products generated from partially N-acetylated chitosan showed that chitosanase II split GlcN-GlcN and GlcNAc-GlcN bonds but not GlcNAc-GlcNAc or GlcN-GlcNAc, suggesting that it is a subclass I chitosanase. It degraded (GlcN)6 to produce (GlcN)3 as main product and small amounts of (GlcN)2 and (GlcN)4. Reaction rate analyses of mono-N-acetylated chitohexaose suggested that the (+3) site of chitosanase II recognizes the GlcNAc residue rather than the GlcN residue of its substrate.
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  • Masanori OHTA, Kenji OHYAMA, Atsushi ASANO, Shin-Ichi YOKOTA, Ahmed Ma ...
    2012 Volume 76 Issue 8 Pages 1540-1543
    Published: August 23, 2012
    Released: August 23, 2012
    [Advance publication] Released: August 07, 2012
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    We screened the gene that encodes tetratricopeptide repeat domain 29 (Ttc29) in the maturing rat testis. Gene expression was determined by Northern blotting of 7-week-old rat testes, and a strong signal was detected close to the 18S rRNA band in addition to two weak high-molecular-weight signals. In situ hybridization revealed that Ttc29 was expressed primarily in the spermatocytes. We evaluated the effect of gonadotropin on Ttc29 expression using hypophysectomized rats. The pituitary was removed from 3-week-old rats, gonadotropin was injected at 5 weeks, and Ttc29 expression was determined at 7 weeks. Although testicular development and hyperplasia of interstitial cells were observed following chorionic gonadotropin treatment after hypophysectomy, Ttc29 expression was upregulated by treatment with follicle-stimulating hormone. Ttc29 encodes axonemal dynein, a component of sperm flagella. Taken together, these data indicate that axonemal dynein expression starts in the spermatocytes and is regulated by follicle-stimulating hormone.
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Biochemistry & Molecular Biology Notes
Biochemistry & Molecular Biology Communication
Food & Nutrition Science Regular Papers
  • Mohammad Norazmi AHMAD, Siew Ling LIEW, Mohd Ambar YARMO, Mamot SAID
    2012 Volume 76 Issue 8 Pages 1438-1444
    Published: August 23, 2012
    Released: August 23, 2012
    [Advance publication] Released: August 07, 2012
    JOURNALS FREE ACCESS
    Protease is one of the most important industrial enzymes with a multitude of applications in both food and non-food sectors. Although most commercial proteases are microbial proteases, the potential of non-conventional protease sources, especially plants, should not be overlooked. In this study, horse mango (Mangifera foetida Lour) fruit, known to produce latex with a blistering effect upon contact with human skin, was chosen as a source of protease, and the effect of the extraction process on its protease activity evaluated. The crude enzyme was extracted from the kernels and extraction was optimized by a response surface methodology (RSM) using a central composite rotatable design (CCRD). The variables studied were pH (x1), CaCl2 (x2), Triton X-100 (x3), and 1,4-dithryeitol (x4). The results obtained indicate that the quadratic model is significant for all the variables tested. Based on the RSM model generated, optimal extraction conditions were obtained at pH 6.0, 8.16 mM CaCl2, 5.0% Triton X-100, and 10.0 mM DTT, and the estimated response was 95.5% (w/w). Verification test results showed that the difference between the calculated and the experimental protease activity value was only 2%. Based on the t-value, the effects of the variables arranged in ascending order of strength were CaCl2< pH < DTT < Triton X-100.
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  • Seung-Hong LEE, Mi-Hwa PARK, Sung-Myung KANG, Seok-Chun KO, Min-Cheol ...
    2012 Volume 76 Issue 8 Pages 1445-1451
    Published: August 23, 2012
    Released: August 23, 2012
    [Advance publication] Released: August 07, 2012
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    Pancreatic β cells are very sensitive to oxidative stress and this might play an important role in β cell death with diabetes. The protective effect of dieckol, one of the phlorotannin polyphenol compounds purified from Ecklonia cava (E. cava), against high glucose-induced oxidative stress was investigated by using rat insulinoma cells. A high-glucose (30 mM) treatment induced the death of rat insulinoma cells, but dieckol, at a concentration 17.5 or 70 µM, significantly inhibited the high-glucose induced glucotoxicity. Treatment with dieckol also dose-dependently reduced thiobarbituric acid reactive substances (TBARS), the generation of intracellular reactive oxygen species (ROS), and the nitric oxide level increased by a high glucose concentration. In addition, the dieckol treatment increased the activities of antioxidative enzymes including catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) in high glucose-pretreated rat insulinoma cells. Dieckol protected rat insulinoma cells damage under high glucose conditions. These effects were mediated by suppressing apoptosis and were associated with increased anti-apoptotic Bcl-2 expression, and reduced pro-apoptotic cleaved caspase-3 expression. These findings indicate that dieckol might be useful as a potential pharmaceutical agent to protect against the glucotoxicity caused by hyperglycemia-induced oxidative stress associated with diabetes.
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  • Tomoyasu KAMIYA, Akira TAKANO, Yuki MATSUZUKA, Nobutaka KUSABA, Motoya ...
    2012 Volume 76 Issue 8 Pages 1511-1517
    Published: August 23, 2012
    Released: August 23, 2012
    [Advance publication] Released: August 07, 2012
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    In Japan, kudzu is a familiar plant, well-known as an ingredient in the Japanese-style confections kudzu-kiri and kudzu-mochi. In this study, we focused on the flower of kudzu (Pueraria thomsonii) and conducted a clinical trial to investigate the effects of Pueraria thomsonii flower extract (PFE) on obesity using obese Japanese males and females (BMI ≥ 25 kg/m2). Eighty-one obese subjects were randomly divided into three groups and consumed test food containing 300 mg of PFE, 200 mg of PFE, and a placebo over 12 weeks. The results indicate that PFE intake reduces BMI and decreases, the visceral fat area, but not the subcutaneous fat area. In addition, the decrease in visceral fat area showed no sexual dimorphism. Consequently, we propose that PFE intake expresses its BMI reduction effects via a decrease in visceral fat area.
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  • Hemant KUMAR, Byung-Wook KIM, Soo-Yeol SONG, Jun-Soo KIM, In-Su KIM, Y ...
    2012 Volume 76 Issue 8 Pages 1518-1522
    Published: August 23, 2012
    Released: August 23, 2012
    [Advance publication] Released: August 07, 2012
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    The effect of α-asarone on impairment of cognitive performance caused by amnesic drug scopolamine was investigated. Treatment with α-asarone attenuated scopolamine-induced cognitive deficits as evaluated by passive avoidance and Y-maze test. Administration of α-asarone for 15 d improved memory and cognitive function as indicated by an increase in transfer latency time and spontaneous alternation in passive avoidance and the Y-maze test respectively. To understand the action of α-asarone, the levels of acetylcholinesterase (AChE), malondialdehyde (MDA), and superoxide dismutase (SOD) in the hippocampus (Hippo) and cerebral cortex (CC) of scopolamine-induced amnesic mice were evaluated. The mice treated with Scopolamine showed increased activity of AChE, MDA and SOD levels in both the Hippo and the CC area. Treatment with α-asarone attenuated the increased activity of AChE and normalized the MDA and SOD levels in the Hippo and the CC area in the scopolamine treated amnesic mice. These results suggest that α-asarone has a beneficial effect in cognitive impairment induced by dysfunction of cholinergic system in brain through inhibition of AChE activity and by influencing the antioxidant defense mechanism.
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  • Tai-Ying CHIOU, Tze Loon NEOH, Takashi KOBAYASHI, Shuji ADACHI
    2012 Volume 76 Issue 8 Pages 1535-1539
    Published: August 23, 2012
    Released: August 23, 2012
    [Advance publication] Released: August 07, 2012
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    Defatted rice bran extracts were obtained by subcritical treatment using aqueous acetone as extractant. Treatment with 40% (v/v) acetone at 230 °C for 5 min yielded an extract with the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (0.274 mmol of ascorbic acid/g of bran), total carbohydrate (0.188 g/g of bran), protein (0.512 g/g of bran), and total phenolic contents (88.2 mg of gallic acid/g of bran). The effect of treatment temperature (70–230 °C) was investigated using 40% (v/v) acetone, and the extract under 230 °C treatment showed the highest levels of all the determinations described above. The extracts obtained with various concentrations of aqueous acetone were subjected to UV absorption spectra and HPLC analysis, and the results showed changes in composition and polarity. Antioxidative activity evaluated against oxidation of bulk linoleic acid of the extract obtained with 80% (v/v) acetone was higher than that not only of the extract from subcritical water treatment but also of that obtained 40% (v/v) acetone treatment.
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  • Noriyuki KOHDA, Shoichiro INOUE, Tsuneyuki NODA, Takao SAITO
    2012 Volume 76 Issue 8 Pages 1544-1548
    Published: August 23, 2012
    Released: August 23, 2012
    [Advance publication] Released: August 07, 2012
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    We evaluated the effects of the intake of various dietary fibers on the fecal excretion of dioxins in rats. The rats were fed five types of dietary fiber diets, including a chitosan diet and control diet, for 20 d and then dioxins (120 ng/rat) were orally administered on day 15. The excretion of fecal dioxins was significantly higher in the chitosan group than in the control group, and dioxin excretion was positively correlated with fecal fat excretion. A comparison of the different types of chitosan showed that the efficacy of chitosan for fecal fat excretion was partly related to its viscosity. The chitosan intake promoted fecal dioxin excretion when the rats were exposed to highly toxic dioxins, and this excretion of fecal dioxins was related to the fecal fat excretion, suggesting that chitosan might be useful for reducing the adverse effects caused by lipophilic xenobiotics.
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Food & Nutrition Science Note
Food & Nutrition Science Communication
Microbiology & Fermentation Technology Regular Papers
  • Jung Sung KIM, Hyun Ju YOU, Hye Yoon KANG, Geun Eog JI
    2012 Volume 76 Issue 8 Pages 1425-1430
    Published: August 23, 2012
    Released: August 23, 2012
    [Advance publication] Released: August 07, 2012
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    Mori Cortex Radicis (MCR), the root bark of Morus alba L., consists of various phytochemicals and exhibits a strong inhibitory effect on tyrosinase. To enhance the tyrosinase inhibitory activity of MCR extract without further purification of bioactive compounds, whole MCR extract was biotransformed with crude enzyme extract from a selected lactic acid bacterium, Leuconostoc paramesenteroides PR (LP). Mulberroside A (MA), a major stilbene glucoside of MCR, contains two β-glucosyl residues at the C3 and C4' positions of oxyresveratrol (OXY). The crude enzyme of LP hydrolyzed the two glycosidic bonds of MA effectively, and 97.1% of MA was biotransformed into OXY within 2 h. Commercial almond β-glucosidase hydrolyzed only one site of the two glycosidic bonds of MA, and 68.7% of MA was biotransformed to OXY-glucoside. The tyrosinase inhibitory activity of the crude extract of MCR was increased approximately 6.5-fold by biotransformation using LP, and the IC50 value of the transformed MCR was 3.7 µg/mL.
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  • Masaru NOMURA
    2012 Volume 76 Issue 8 Pages 1459-1462
    Published: August 23, 2012
    Released: August 23, 2012
    [Advance publication] Released: August 07, 2012
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    Plasminogen was incubated with lactic acid bacteria and the plasmin activity in the mixture was measured. Three of 15 strains tested revealed significant plasminogen activation ability. Lactococcus lactis subsp. lactis biovar diacetylactis NIAI C59 showed the highest activity. The strain activated not only human plasminogen but also bovine plasminogen. The activity demonstrated a high level of thermal stability within a range of pH 3.0–9.0. The plasminogen activator activity in strain C59 increased after 15 h of cultivation, and reached a plateau after 21 h. A remarkable amount of activity was transferred to the solution when C59 cells were incubated in buffer solutions at pH 9.0 and above.
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  • Takashi NEMOTO, Jun-ichi MARUYAMA, Katsuhiko KITAMOTO
    2012 Volume 76 Issue 8 Pages 1477-1483
    Published: August 23, 2012
    Released: August 23, 2012
    [Advance publication] Released: August 07, 2012
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    Aspergillus oryzae strains express α-amylases abundantly, and the genome reference strain RIB40 has three α-amylase genes (amyA, amyB, and amyC). However, there is no information on the contribution ratios of individual α-amylase genes to total expression. In this study, we generated single, double, and triple disruptants of α-amylase genes by employing a strain (ΔligD) with high gene-targeting efficiency and pyrG marker recycling in A. oryzae. All the disruptants showed reduced activities of α-amylases, and the triple disruptant completely lost activity. Comparative analyses of the activities and mRNA amounts of the α-amylases suggest that the contribution of amyA to the α-amylase expression is smaller than those of amyB and amyC. The present study suggests that the ability to express a large amount of α-amylases in A. oryzae is attributed to gene duplication of genes such as amyB and amyC.
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  • Wichai SOEMPHOL, Natsaran SAICHANA, Toshiharu YAKUSHI, Osao ADACHI, Ka ...
    2012 Volume 76 Issue 8 Pages 1497-1505
    Published: August 23, 2012
    Released: August 23, 2012
    [Advance publication] Released: August 07, 2012
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    Further upstream of sldSLC, genes for FAD-dependent D-sorbitol dehydrogenase in Gluconobacter frateurii, three additional genes (sldR, xdhA, and perA) are found: for a transcriptional regulator, NAD(P)-dependent xylitol dehydrogenase, and a transporter protein, a member of major facilitator superfamily, respectively. xdhA and perA but not sldR were found to be in the same transcriptional unit. Disruption of sldR resulted in a dramatic decrease in sldSLC promoter activity, indicating that it is an activator for sldSLC expression. The recombinant protein of XdhA expressed in Escherichia coli showed NAD-dependent dehydrogenase activities with xylitol and D-sorbitol, but a mutant strain defective in this gene showed similar activities with both substrates as compared to the wild-type strain. Nonetheless, the growth of the xdhA mutant strain on D-sorbitol and xylitol was retarded, and so was that of a mutant strain defective in perA. These results indicate that xdhA and perA are involved in assimilation of D-sorbitol and xylitol.
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  • Hideyuki TAMEGAI, Shun NISHIKAWA, Minami HAGA, Douglas H. BARTLETT
    2012 Volume 76 Issue 8 Pages 1506-1510
    Published: August 23, 2012
    Released: August 23, 2012
    [Advance publication] Released: August 07, 2012
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    It is known that the facultative piezophile Shewanella violacea DSS12 alters its respiratory components under the influence of hydrostatic pressure during growth. This can be considered one of the mechanisms of bacterial adaptation to high pressure. In this study, we investigated the respiratory system of another well-studied piezophile, Photobacterium profundum SS9. We analyzed cytochrome contents, the expression of genes encoding respiratory components in P. profundum SS9 grown under various conditions, and the pressure dependency of the terminal oxidase activities. Activity was more tolerant of relatively high pressures, such as 125 MPa when the cells were grown under high pressure as compared with cells grown under atmospheric pressure. Such properties observed are similar to the case of S. violacea. However, the contents of the cytochromes and expression of the respiratory genes were not influenced by growth pressure in P. profundum SS9, inconsistent with the case of S. violacea. We suggest that the mechanism of the piezoadaptation of the respiratory system of P. profundum SS9 differs from that of S. violacea, as described above, and that each strain chooses its own strategy.
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  • Bang-Jau YOU, Hong-Zin LEE, Kuang-Ren CHUNG, Miin-Huey LEE, Mei-Jung H ...
    2012 Volume 76 Issue 8 Pages 1529-1534
    Published: August 23, 2012
    Released: August 23, 2012
    [Advance publication] Released: August 07, 2012
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    Submerged cultures of Ganoderma lucidum are used to produce fungal mycelium, which is used as a functional food and in the production of various triterpenoids, including ganoderic acids (GAs). Specific culture approaches that produce fungal mycelium with high levels of GAs and good biological activity are critical in the functional food industry. In this study, a solid-medium culture approach to producing mycelium was compared to the submerged culture system. Production of GAs, biomass, intracellular polysaccharides, and cytotoxicity of the cultured mycelium were compared as between solid and submerged culture. Growing G. lucidum strains on solid potato dextrose agar medium increased biomass, the production of ganoderic acid 24 (lanosta-7,9(11), 24-trien-3α-o1-26-oic acid), GAs, and total intracellular polysaccharides as compared to fungi grown in submerged culture. Triterpenoid-enriched methanol extracts of mycelium from solid-medium culture showed higher cytotoxicity than those from submerged culture. The IC50 values of methanol extracts from solid-medium culture were 11.5, 8.6, and 9.9 times less than submerged culture on human lung cancer cells CH27, melanoma cells M21, and oral cancer cells HSC-3 respectively. The squalene synthase and lanosterol synthase coding genes had higher expression on the culture of solid potato dextrose medium. This is the first report that solid-medium culture is able to increase GA production significantly as compared to submerged culture and, in the process, produces much higher biological activity. This indicates that it may be possible to enhance the production of GAs by implementing mycelium culture on solid medium.
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Microbiology & Fermentation Technology Note
  • Hiroyuki IGUCHI, Izuru SATO, Maiko SAKAKIBARA, Hiroya YURIMOTO, Yasuyo ...
    2012 Volume 76 Issue 8 Pages 1580-1583
    Published: August 23, 2012
    Released: August 23, 2012
    [Advance publication] Released: August 07, 2012
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    Plants have been reported to emit methane as well as methanol originating in their cell-wall constituents. We investigated methanotrophs in the phyllosphere by the enrichment culture method with methane as sole carbon source. We enriched methanotrophs from the leaves, flowers, bark, and roots of various plants. Analysis of the pmoA and mxaF genes retrieved from the enrichment cultures revealed that methanotrophs closely related to the genera Methylomonas, Methylosinus, and Methylocystis inhabit not only the rhizosphere but also the phyllosphere, together with methanol-utilizing bacteria.
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Environmental Science Regular Paper
  • Ji Young CHO
    2012 Volume 76 Issue 8 Pages 1452-1458
    Published: August 23, 2012
    Released: August 23, 2012
    [Advance publication] Released: August 07, 2012
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    The KNS-16 algicidal strain was isolated from a harmful alga bloom (HAB) area and identified as Alteromonas sp. based on 16S rDNA sequencing. The KNS-16 strain was found to control HABs by producing algicidal compounds in an indirect interaction. Four active compounds were isolated from KNS-16 culture, and their structures were analyzed by interpreting nuclear magnetic resonance and mass spectroscopy data. The structures were identified as 2-undecen-1'-yl-4-quinolone (1), 2-undecyl-4-quinolone (2), 3-hexyl-6-pentyl-4-hydroxyl-2H-pyran-2-one (3), and 6-heptyl-3-hexyl-4-hydroxyl-2H-pyran-2-one (4). Compound 1 was most active against HABs such as Heterosigma akashiwo, Cochlodinium polykrikoides, and Alexandrium tamarense with LC50 values of 0.5–1.1 µg/mL. The four compounds exhibited high LC50 values against aquaculture algae such as Tetaselmis suecica, Isochrysis galbana, and Pavlova lutheri at 39–66 µg/mL. Based on toxicity tests on the brine shrimp Artemia salina and the rotifer Brachionus rotundiformis, the four compounds showed ranges of 409–608 and 189–224 µg/mL of LC50 for the two organisms, respectively. The LC50 values for juvenile fish of Sebastes schlegelii were 284–304 µg/mL.
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Environmental Science Note
  • Daekyung KIM, Sayaka NARUSE, Kazushi KADOMURA, Takuji NAKASHIMA, Zedon ...
    2012 Volume 76 Issue 8 Pages 1561-1564
    Published: August 23, 2012
    Released: August 23, 2012
    [Advance publication] Released: August 07, 2012
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    A time-course analysis of reactive oxygen species (ROS) generation in fertilized eggs of the devil stinger (Inimicus japonicus) from 0 h post-fertilization (hpf) to the early larval stage indicated that the ROS level was highest in the 22 hpf embryo, and declined thereafter. Phorbol myristate acetate (PMA) had no effect on ROS generation by the 22 hpf embryo, whereas PMA significantly increased larval ROS generation, suggesting that the ROS generation mechanisms of the 22 hpf embryo and larva are different at least in terms of PMA-responsiveness. Our results suggest the presence of a specific ROS generation system in devil stinger embryo which can be transitionally activated during embryogenesis.
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