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Sample records for gentiobiose

  1. Activation energies of fragmentations of disaccharides by tandem mass spectrometry.

    Science.gov (United States)

    Kuki, Ákos; Nagy, Lajos; Szabó, Katalin E; Antal, Borbála; Zsuga, Miklós; Kéki, Sándor

    2014-03-01

    A simple multiple collision model for collision induced dissociation (CID) in quadrupole was applied for the estimation of the activation energy (E(o)) of the fragmentation processes for lithiated and trifluoroacetated disaccharides, such as maltose, cellobiose, isomaltose, gentiobiose, and trehalose. The internal energy-dependent rate constants k(E(int)) were calculated using the Rice-Ramsperger-Kassel-Marcus (RRKM) or the Rice-Ramsperger-Kassel (RRK) theory. The E(o) values were estimated by fitting the calculated survival yield (SY) curves to the experimental ones. The calculated E(o) values of the fragmentation processes for lithiated disaccharides were in the range of 1.4-1.7 eV, and were found to increase in the order trehalose < maltose < isomaltose < cellobiose < gentiobiose.

  2. 15-2-4 :セルロース生産微生物による機能性セルロースの創製; セルロース合成における高次構造制御

    OpenAIRE

    天野, 良彦; 神田, 鷹久

    2004-01-01

    We tried to investigated various carbohydrates and cellulose degrading enzyme activityin the culture broth of cellulose producing microorganism, Acetobacter xylinum to clarify, the role of cellulase for cellulose production. Cerboxymethylcellulose (CMC) degrading activity and various sugars in addition to cellulose were detected in the culture broth after one day culture. These sugars increased gradually and were identified to some kinds of β-linked disaccharides such as gentiobiose and cello...

  3. CHEMICAL CONSTITUENTS OF PTEROCEPHALUS HOOKERI%匙叶翼首花的化学成分

    Institute of Scientific and Technical Information of China (English)

    田军; 吴凤锷; 丘明华; 聂瑞麟

    2000-01-01

    从药用植物匙叶翼首花(Pterocephalus hookeri)中分离了7个化合物.通过波谱分析及已知物数据对照,分别鉴定为songoroside A(1),loganin(2),软脂酸(palmitic acid,3),乌索酸(ursolic acid,4),齐墩果酸(oleanolic acid,5),β-谷甾醇(β-sitosterol,6),β-龙胆二糖(β-gentiobiose,7),其中2是主要成分,上述化合物在该植物中均为首次报道.

  4. Antioxidant and Anti-Fatigue Constituents of Okra

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    Fangbo Xia

    2015-10-01

    Full Text Available Okra (Abelmoschus esculentus (L. Moench, a healthy vegetable, is widely spread in tropical and subtropical areas. Previous studies have proven that okra pods possess anti-fatigue activity, and the aim of this research is to clarify the anti-fatigue constituents. To achieve this, we divided okra pods (OPD into seeds (OSD and skins (OSK, and compared the contents of total polysaccharides, total polyphenols, total flavonoids, isoquercitrin, and quercetin-3-O-gentiobiose and the antioxidant activity in vitro and anti-fatigue activity in vivo between OSD and OSK. The contents of total polyphenols and total polysaccharides were 29.5% and 14.8% in OSD and 1.25% and 43.1% in OSK, respectively. Total flavonoids, isoquercitrin and quercetin-3-O-gentiobiose (5.35%, 2.067% and 2.741%, respectively were only detected in OSD. Antioxidant assays, including 1-diphenyl-2-picrylhydrazyl (DPPH scavenging, ferric reducing antioxidant power (FRAP and reducing power test, and weight-loaded swimming test showed OSD possessed significant antioxidant and anti-fatigue effects. Moreover, biochemical determination revealed that that anti-fatigue activity of OSD is caused by reducing the levels of blood lactic acid (BLA and urea nitrogen (BUN, enhancing hepatic glycogen storage and promoting antioxidant ability by lowering malondialdehyde (MDA level and increasing superoxide dismutase (SOD and glutathione peroxidase (GSH-PX levels. These results proved okra seeds were the anti-fatigue part of okra pods and polyphenols and flavonoids were active constituents.

  5. Steroidal and triterpenoidal glucosides from Passiflora alata

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    Reginatto Flávio H.

    2001-01-01

    Full Text Available Five glycosides were isolated from leaves of P. alata. The structures 1-5 were obtained through extensive spectral analyses as 3-O-beta-D-glucopyranosyl-stigmasterol (1, 3-O-beta-D-glucopyranosyl-oleanolic acid (2, 3-O-beta-D-glucopyranosyl-(1->3-beta-D-glucopyranosyl-oleanolic acid (3, 3-O-beta-D-glucopyranosyl-(1->2-beta-D-glucopyranosyl-oleanolic acid (4 and 9,19-cyclolanost-24Z-en-3beta,21,26-trihydroxy-3,26-di-O-gentiobiose (5. Comparison of the TLC profiles of the hydroethanolic extracts from leaves of other Passiflora species found in the south of Brazil (P. actinia, P. caerulea, P. edulis var. flavicarpa, P. elegans, P. foetida, P. misera and P. tenuifila showed that only P. alata presented saponin accumulation.

  6. Plausible authentication of manuka honey and related products by measuring leptosperin with methyl syringate.

    Science.gov (United States)

    Kato, Yoji; Fujinaka, Rie; Ishisaka, Akari; Nitta, Yoko; Kitamoto, Noritoshi; Takimoto, Yosuke

    2014-07-01

    Manuka honey, obtained from Leptospermum scoparium flowers in New Zealand, has strong antibacterial properties. In this study, plausible authentication of the manuka honey was inspected by measuring leptosperin, methyl syringate 4-O-β-D-gentiobiose, along with methyl syringate. Despite a gradual decrease in methyl syringate content over 30 days at 50 °C, even at moderate 37 °C, leptosperin remained stable. A considerable correlation between nonperoxide antibacterial activity and leptosperin content was observed in 20 certified manuka honey samples. Leptosperin and methyl syringate in manuka honey and related products were analyzed using HPLC connected with mass spectrometry. One noncertified brand displayed significant variations in the leptosperin and methyl syringate contents between two samples obtained from different regions. Therefore, certification is clearly required to protect consumers from disguised and/or low-quality honey. Because leptosperin is stable during storage and specific to manuka honey, its measurement may be applicable for manuka honey authentication.

  7. Lactobacillus nagelii sp. nov., an organism isolated from a partially fermented wine.

    Science.gov (United States)

    Edwards, C G; Collins, M D; Lawson, P A; Rodriguez, A V

    2000-03-01

    A Gram-positive rod was isolated from a commercial grape wine undergoing a sluggish/stuck alcoholic fermentation. The organism produced DL-lactic acid from glucose without gas formation, produced dextran from sucrose, hydrolysed aesculin and fermented galactose, D-glucose, D-fructose, D-mannose, L-sorbose, rhamnose, mannitol, sorbitol, methyl alpha-D-glucoside, N-acetylglucosamine, amygdalin, salicin, cellobiose, maltose, sucrose, trehalose and beta-gentiobiose. 16S rRNA gene sequence analysis revealed that the isolate was phylogenetically a member of the genus Lactobacillus and formed a distinct subline within the Lactobacillus casei cluster of species. On the basis of phenotypic and phylogenetic evidence, Lactobacillus nagelii sp. nov. ATCC 700692T is proposed as a new species.

  8. Transcriptional Analysis of Prebiotic Uptake and Catabolism by Lactobacillus acidophilus NCFM

    DEFF Research Database (Denmark)

    Andersen, Joakim Mark; Barrangou, Rodolphe; Abou Hachem, Maher

    2012-01-01

    The human gastrointestinal tract can be positively modulated by dietary supplementation of probiotic bacteria in combination with prebiotic carbohydrates. Here differential transcriptomics and functional genomics were used to identify genes in Lactobacillus acidophilus NCFM involved in the uptake...... and catabolism of 11 potential prebiotic compounds consisting of α- and β- linked galactosides and glucosides. These oligosaccharides induced genes encoding phosphoenolpyruvate-dependent sugar phosphotransferase systems (PTS), galactoside pentose hexuronide (GPH) permease, and ATP-binding cassette (ABC......-phospho-β-glucosidases implicated in the catabolism of gentiobiose and cellobiose. These findings highlight the broad oligosaccharide metabolic repertoire of L. acidophilus NCFM and establish a platform for selection and screening of both probiotic bacteria and prebiotic compounds that may positively...

  9. Transglycosylation reactions of Bacillus stearothermophilus maltogenic amylase with acarbose and various acceptors

    Energy Technology Data Exchange (ETDEWEB)

    Hwa Park, K.; Jeong Kim, M.; Seob Lee, H.; Kim, D. [Department of Food Science and Technology and Research Center for New Bio-Materials in Agriculture, Seoul National University, Suwon (Korea, Republic of); Soo Han, N.; Robyt, J.F. [Laboratory for Carbohydrate Chemistry and Enzymology, Department of Biochemistry and Biophysics, Iowa State University, Ames, IA (United States)

    1998-12-15

    It was observed that Bacillus stearothermophilus maltogenic amylase cleaved the first glycosidic bond of acarbose to produce glucose and a pseudotrisaccharide (PTS) that was transferred to C-6 of the glucose to give an {alpha}-(1-6) glycosidic linkage and the formation of isoacarbose. The addition of a number of different carbohydrates to the digest gave transfer products in which PTS was primarily attached {alpha}-(1-6) to d-glucose, d-mannose, d-galactose, and methyl {alpha}-d-glucopyranoside. With d-fructopyranose and d-xylopyranose, PTS was linked {alpha}-(1-5) and {alpha}-(1-4), respectively. PTS was primarily transferred to C-6 of the nonreducing residue of maltose, cellobiose, lactose, and gentiobiose. Lesser amounts of {alpha}-(1-3) and/or {alpha}-(1-4) transfer products were also observed for these carbohydrate acceptors. The major transfer product to sucrose gave PTS linked {alpha}-(1-4) to the glucose residue. {alpha},{alpha}-Trehalose gave two major products with PTS linked {alpha}-(1-6) and {alpha}-(1-4). Maltitol gave two major products with PTS linked {alpha}-(1-6) and {alpha}-(1-4) to the glucopyranose residue. Raffinose gave two major products with PTS linked {alpha}-(1-6) and {alpha}-(1-4) to the d-galactopyranose residue. Maltotriose gave two major products with PTS linked {alpha}-(1-6) and {alpha}-(1-4) to the nonreducing end glucopyranose residue. Xylitol gave PTS linked {alpha}-(1-5) as the major product and d-glucitol gave PTS linked {alpha}-(1-6) as the only product. The structures of the transfer products were determined using thin layer-chromatography, high-performance ion chromatography, enzyme hydrolysis, methylation analysis and {sup 13}C NMR spectroscopy. The best acceptor was gentiobiose, followed closely by maltose and cellobiose, and the weakest acceptor was d-glucitol. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  10. Influence of light and temperature on gene expression leading to accumulation of specific flavonol glycosides and hydroxycinnamic acid derivatives in kale (Brassica oleracea var. sabellica

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    Susanne eNeugart

    2016-03-01

    Full Text Available Light intensity and temperature are very important signals for the regulation of plant growth and development. Plants subjected to less favorable light or temperature conditions often respond with accumulation of secondary metabolites. Some of these metabolites have been identified as bioactive compounds, considered to exert positive effects on human health when consumed regularly. In order to test a typical range of growth parameters for the winter crop Brassica oleracea var. sabellica, plants were grown either at 400 µmol m-2 s-1 or 100 µmol m-2 s-1 at 10°C, or at 400 µmol m-2 s-1 with 5°C or 15°C. The higher light intensity overall increased flavonol content of leaves, favoring the main quercetin glycosides, a caffeic acid monoacylated kaempferol triglycoside, and disinapoyl-gentiobiose. The higher temperature mainly increased the hydroxycinnamic acid derivative disinapoyl-gentiobiose, while at lower temperature synthesis is in favor of very complex sinapic acid acylated flavonol tetraglycosides such as kaempferol-3-O-sinapoyl-sophoroside-7-O-diglucoside. A global analysis of light and temperature dependent alterations of gene expression in B. oleracea var. sabellica leaves was performed with the most comprehensive Brassica microarray. When compared to the light experiment much less genes were differentially expressed in kale leaves grown at 5°C or 15°C. A structured evaluation of differentially expressed genes revealed the expected enrichment in the functional categories of e.g. protein degradation at different light intensities or phytohormone metabolism at different temperature. Genes of the secondary metabolism namely phenylpropanoids are significantly enriched with both treatments. Thus, the genome of B. oleracea was screened for predicted genes putatively involved in the biosynthesis of flavonoids and hydroxycinnamic acid derivatives. All identified B. oleracea genes were analyzed for their most specific 60-mer oligonucleotides

  11. Influence of Light and Temperature on Gene Expression Leading to Accumulation of Specific Flavonol Glycosides and Hydroxycinnamic Acid Derivatives in Kale (Brassica oleracea var. sabellica).

    Science.gov (United States)

    Neugart, Susanne; Krumbein, Angelika; Zrenner, Rita

    2016-01-01

    Light intensity and temperature are very important signals for the regulation of plant growth and development. Plants subjected to less favorable light or temperature conditions often respond with accumulation of secondary metabolites. Some of these metabolites have been identified as bioactive compounds, considered to exert positive effects on human health when consumed regularly. In order to test a typical range of growth parameters for the winter crop Brassica oleracea var. sabellica, plants were grown either at 400 μmol m(-2) s(-1) or 100 μmol m(-2) s(-1) at 10°C, or at 400 μmol m(-2) s(-1) with 5 or 15°C. The higher light intensity overall increased flavonol content of leaves, favoring the main quercetin glycosides, a caffeic acid monoacylated kaempferol triglycoside, and disinapoyl-gentiobiose. The higher temperature mainly increased the hydroxycinnamic acid derivative disinapoyl-gentiobiose, while at lower temperature synthesis is in favor of very complex sinapic acid acylated flavonol tetraglycosides such as kaempferol-3-O-sinapoyl-sophoroside-7-O-diglucoside. A global analysis of light and temperature dependent alterations of gene expression in B. oleracea var. sabellica leaves was performed with the most comprehensive Brassica microarray. When compared to the light experiment much less genes were differentially expressed in kale leaves grown at 5 or 15°C. A structured evaluation of differentially expressed genes revealed the expected enrichment in the functional categories of e.g. protein degradation at different light intensities or phytohormone metabolism at different temperature. Genes of the secondary metabolism namely phenylpropanoids are significantly enriched with both treatments. Thus, the genome of B. oleracea was screened for predicted genes putatively involved in the biosynthesis of flavonoids and hydroxycinnamic acid derivatives. All identified B. oleracea genes were analyzed for their most specific 60-mer oligonucleotides present on the

  12. Phytochemical fingerprints of lime honey collected in serbia.

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    Gašić, Uroš; Šikoparija, Branko; Tosti, Tomislav; Trifković, Jelena; Milojković-Opsenica, Dušanka; Natić, Maja; Tešić, Živoslav

    2014-01-01

    Composition of phenolic compounds and the sugar content were determined as the basis for characterization of lime honey from Serbia. Particular attention was given to differences in phytochemical profiles of ripe and unripe lime honey and lime tree nectar. Melissopalynological analysis confirmed domination of Tilia nectar in all analyzed samples. Phenolic acids, abscisic acid, flavonoids, and flavonoid glycosides were determined by means of ultra-HPLC coupled with a hybrid mass spectrometer (UHPLC-OrbiTrap). Sugar content was determined using high-performance anion-exchange chromatography with amperometric detection. Similar phenolic compounds characterized unripe and ripe honeys, while the lime tree nectar profile showed notable differences. Compared to lime tree nectar, a high amount of chrysin, pinocembrin, and galangin were detected in both ripe and unripe lime honey. Fructose and glucose were the major constituents of all investigated samples, and amounts were within the limits established by European Union legislation. Sucrose content in the nectar sample was up to two-fold higher when compared to all honey samples. Isomaltose and gentiobiose with turanose content were different in analyzed production stages of lime honey.

  13. Factors Involved in the In Vitro Fermentability of Short Carbohydrates in Static Faecal Batch Cultures

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    Eva Gietl

    2012-01-01

    Full Text Available In recent years, research has focused on the positive effects of prebiotics on intestinal health and gut microbiota. The relationship between their chemical structure and their fermentation pattern by human intestinal microbiota is still not well understood. The aim of this study was to improve understanding of this relationship and identify factors that may be used to design galactooligosaccharides that reach more distal regions than commercial prebiotics which mainly target the proximal colon. The following factors were investigated: monomer type, linkage, substitution, and degree of polymerisation. Total organic acid production from sugars by faecal bacteria was fitted to a model which allowed an estimate of the time when half of the maximal organic acid concentration was reached (T50 in static faecal batch cultures. The different factors can be grouped by their effectiveness at prolonging fermentation time as follows: substitution is most effective, with methylgalactose, β-galactose-pentaacetate, D-fucose, and galactitol fermented more slowly than D-galactose. Monomers and linkage also influence fermentation time, with L rhamnose, arabinose, melezitose, and xylose being fermented significantly slower than D-glucose (P<0.05, maltose, isomaltose, cellobiose, and gentiobiose showing that Glcα1-6Glc and Glcβ1-4Glc were utilised slowest. Chain length had the smallest effect on fermentation time.

  14. Influence of length and conformation of saccharide head groups on the mechanics of glycolipid membranes: Unraveled by off-specular neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Akihisa, E-mail: ayamamoto@icems.kyoto-u.ac.jp, E-mail: tanaka@uni-heidelberg.de; Tanaka, Motomu, E-mail: ayamamoto@icems.kyoto-u.ac.jp, E-mail: tanaka@uni-heidelberg.de [Physical Chemistry of Biosystems, Institute of Physical Chemistry, University of Heidelberg, 69120 Heidelberg (Germany); Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto 606-8501 (Japan); Abuillan, Wasim; Körner, Alexander [Physical Chemistry of Biosystems, Institute of Physical Chemistry, University of Heidelberg, 69120 Heidelberg (Germany); Burk, Alexandra S. [Physical Chemistry of Biosystems, Institute of Physical Chemistry, University of Heidelberg, 69120 Heidelberg (Germany); Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, 76021 Karlsruhe (Germany); Ries, Annika [Institute of Organic and Biomolecular Chemistry, University of Göttingen, 37077 Göttingen (Germany); Werz, Daniel B. [Institute of Organic Chemistry, Technische Universität Braunschweig, 38106 Braunschweig (Germany); Demé, Bruno [Institut Laue-Langevin, 38042 Grenoble Cedex 9, Grenoble (France)

    2015-04-21

    The mechanical properties of multilayer stacks of Gb3 glycolipid that play key roles in metabolic disorders (Fabry disease) were determined quantitatively by using specular and off-specular neutron scattering. Because of the geometry of membrane stacks deposited on planar substrates, the scattered intensity profile was analyzed in a 2D reciprocal space map as a function of in-plane and out-of-plane scattering vector components. The two principal mechanical parameters of the membranes, namely, bending rigidity and compression modulus, can be quantified by full calculation of scattering functions with the aid of an effective cut-off radius that takes the finite sample size into consideration. The bulkier “bent” Gb3 trisaccharide group makes the membrane mechanics distinctly different from cylindrical disaccharide (lactose) head groups and shorter “bent” disaccharide (gentiobiose) head groups. The mechanical characterization of membranes enriched with complex glycolipids has high importance in understanding the mechanisms of diseases such as sphingolipidoses caused by the accumulation of non-degenerated glycosphingolipids in lysosomes or inhibition of protein synthesis triggered by the specific binding of Shiga toxin to Gb3.

  15. Bitter Gentian Teas: Nutritional and Phytochemical Profiles, Polysaccharide Characterisation and Bioactivity.

    Science.gov (United States)

    Olennikov, Daniil N; Kashchenko, Nina I; Chirikova, Nadezhda K; Koryakina, Lena P; Vladimirov, Leonid N

    2015-11-05

    As a result of the wide distribution of herbal teas the data on nutritional characterisation, chemical profile and biological activity of these products are required. The decoctions of Gentiana algida, G. decumbens, G. macrophylla and G. triflora herb teas were nutritionally characterized with respect to their macronutrients, demonstrating the predominance of polysaccharides and low lipid content. Gentian decoctions were also submitted to a microcolumn RP-HPLC-UV analysis of phytochemicals demonstrating a high content of iridoids (177.18-641.04 μg/mL) and flavonoids (89.15-405.71 μg/mL). Additionally, mangiferin was detected in samples of G. triflora tea (19.89 μg/mL). Five free sugars (fructose, glucose, sucrose, gentiobiose, gentianose) were identified in all gentian teas studied, as well as six organic acids (malic, citric, tartaric, oxalic, succinic, quinic). Pectic polysaccharides with a high content of rhamnogalacturonans and arabinogalactans were also identified and characterized in gentian decoctions for the first time. Gentian tea decoctions and their specific compounds (gentiopicroside, loganic acid-6'-O-β-d-glucoside, isoorientin, isoorientin-4'-O-β-d-glucoside, mangiferin, water-soluble polysaccharides) showed a promising antimicrobial, anti-inflammatory and antioxidant potentials. Evidences obtained indicate the prospective use of gentian herb teas as food products and medicines.

  16. Bitter Gentian Teas: Nutritional and Phytochemical Profiles, Polysaccharide Characterisation and Bioactivity

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    Daniil N. Olennikov

    2015-11-01

    Full Text Available As a result of the wide distribution of herbal teas the data on nutritional characterisation, chemical profile and biological activity of these products are required. The decoctions of Gentiana algida, G. decumbens, G. macrophylla and G. triflora herb teas were nutritionally characterized with respect to their macronutrients, demonstrating the predominance of polysaccharides and low lipid content. Gentian decoctions were also submitted to a microcolumn RP-HPLC-UV analysis of phytochemicals demonstrating a high content of iridoids (177.18–641.04 μg/mL and flavonoids (89.15–405.71 μg/mL. Additionally, mangiferin was detected in samples of G. triflora tea (19.89 μg/mL. Five free sugars (fructose, glucose, sucrose, gentiobiose, gentianose were identified in all gentian teas studied, as well as six organic acids (malic, citric, tartaric, oxalic, succinic, quinic. Pectic polysaccharides with a high content of rhamnogalacturonans and arabinogalactans were also identified and characterized in gentian decoctions for the first time. Gentian tea decoctions and their specific compounds (gentiopicroside, loganic acid-6′-O-β-d-glucoside, isoorientin, isoorientin-4′-O-β-d-glucoside, mangiferin, water-soluble polysaccharides showed a promising antimicrobial, anti-inflammatory and antioxidant potentials. Evidences obtained indicate the prospective use of gentian herb teas as food products and medicines.

  17. Influence of length and conformation of saccharide head groups on the mechanics of glycolipid membranes: Unraveled by off-specular neutron scattering

    Science.gov (United States)

    Yamamoto, Akihisa; Abuillan, Wasim; Burk, Alexandra S.; Körner, Alexander; Ries, Annika; Werz, Daniel B.; Demé, Bruno; Tanaka, Motomu

    2015-04-01

    The mechanical properties of multilayer stacks of Gb3 glycolipid that play key roles in metabolic disorders (Fabry disease) were determined quantitatively by using specular and off-specular neutron scattering. Because of the geometry of membrane stacks deposited on planar substrates, the scattered intensity profile was analyzed in a 2D reciprocal space map as a function of in-plane and out-of-plane scattering vector components. The two principal mechanical parameters of the membranes, namely, bending rigidity and compression modulus, can be quantified by full calculation of scattering functions with the aid of an effective cut-off radius that takes the finite sample size into consideration. The bulkier "bent" Gb3 trisaccharide group makes the membrane mechanics distinctly different from cylindrical disaccharide (lactose) head groups and shorter "bent" disaccharide (gentiobiose) head groups. The mechanical characterization of membranes enriched with complex glycolipids has high importance in understanding the mechanisms of diseases such as sphingolipidoses caused by the accumulation of non-degenerated glycosphingolipids in lysosomes or inhibition of protein synthesis triggered by the specific binding of Shiga toxin to Gb3.

  18. Conjugation of the mycotoxins alternariol and alternariol monomethyl ether in tobacco suspension cells.

    Science.gov (United States)

    Hildebrand, Andreas A; Kohn, Beate N; Pfeiffer, Erika; Wefers, Daniel; Metzler, Manfred; Bunzel, Mirko

    2015-05-20

    The mycotoxins alternariol (AOH) and alternariol-9-O-methyl ether (AME) carry three and two phenolic hydroxyl groups, respectively, which makes them candidates for the formation of conjugated metabolites in plants. Such conjugates may escape routine methods of analysis and have therefore been termed masked or, more recently, modified mycotoxins. We report now that AOH and AME are extensively conjugated in suspension cultures of tobacco BY-2 cells. Five conjugates of AOH were identified by MS and NMR spectroscopy as β-D-glucopyranosides (attached in AOH 3- or 9-position) as well as their 6'-malonyl derivatives, and as a gentiobiose conjugate. For AME, conjugation resulted in the d-glucopyranoside (mostly attached in the AME 3-position) and its 6'- and 4'-malonyl derivatives. Pronounced differences were noted for the quantitative pattern of AOH and AME conjugates as well as for their phytotoxicity. Our in vitro study demonstrates for the first time that masked mycotoxins of AOH and AME can be formed in plant cells.

  19. Trans-glycosylation capacity of a highly glycosylated multi-specific β-glucosidase from Fusarium solani.

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    Boudabbous, Manel; Ben Hmad, Ines; Saibi, Walid; Mssawra, Mariem; Belghith, Hafedh; Gargouri, Ali

    2017-04-01

    An extracellular β-glucosidase from Fusaruim solani cultivated on wheat bran was purified by only two chromatographic steps. The purified enzyme exhibited optimal temperature and pH at 60 °C and pH 5, respectively. The purified β-glucosidase behaves as a very large protein due to its high degree of glycosylation. More interestingly, the endoglycosidase H (Endo H) treatment led to 97.55% loss of its initial activity after 24 h of treatment. Besides, the addition of Tunicamycin (nucleoside antibiotic blocking the N-glycosylation first step) during the culture of the fungus affected seriously the glycosylation of the enzyme. Both treatments (endo H and Tunicamycin) strengthened the idea that the hyperglycosylation is involved in the β-glucosidase activity and thermostability. This enzyme was also shown to belong to class III of β-glucosidases (multi-specific) since it was able to act on either cellobiose, gentiobiose or sophorose which are disaccharide composed of two units of D-glucose connected by β1-4, β1-6 and β1-2 linkage, respectively. The β-glucosidase activity was strongly enhanced by ferrous ion (Fe(2+)) and high ionic strength (1 M KCl). The purified enzyme exhibited an efficient transglycosylation capacity allowing the synthesis of cellotriose and cellotetraose using cellobiose as donor.

  20. Gentio-oligosaccharides from Leuconostoc mesenteroides NRRL B-1426 dextransucrase as prebiotics and as a supplement for functional foods with anti-cancer properties.

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    Kothari, Damini; Goyal, Arun

    2015-02-01

    Gentio-oligosaccharides (GnOS) were synthesized by the acceptor reaction of dextransucrase from Leuconostoc mesenteroides NRRL B-1426 with gentiobiose and sucrose. GnOS were purified by gel permeation chromatography using a Bio-Gel P-2 column and identified by mass spectrometry. The purified GnOS (degree of polymerization ≥3) were investigated for their in vitro prebiotic and cytotoxic activity. GnOS exhibited a significantly lower degree of digestibility of 18.1% by simulated human gastric juice (pH 1.0) and 7.1% by human α-amylase (pH 7.0) after 6 h, whereas inulin, a standard prebiotic, showed 39.7% and 12.8% of digestibility, respectively. The prebiotic score showed that GnOS significantly supported the growth of probiotics such as Bifidobacterium infantis and Lactobacillus acidophilus and was comparable to that of inulin. The selective inhibitory effect of GnOS on human colon carcinoma (HT-29) cells revealed its potential as an anti-cancer agent that can serve as a functional food additive for the benefit of human health.

  1. UVA, UVB Light Doses and Harvesting Time Differentially Tailor Glucosinolate and Phenolic Profiles in Broccoli Sprouts

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    Melissa Moreira-Rodríguez

    2017-06-01

    Full Text Available Broccoli sprouts contain health-promoting glucosinolate and phenolic compounds that can be enhanced by applying ultraviolet light (UV. Here, the effect of UVA or UVB radiation on glucosinolate and phenolic profiles was assessed in broccoli sprouts. Sprouts were exposed for 120 min to low intensity and high intensity UVA (UVAL, UVAH or UVB (UVBL, UVBH with UV intensity values of 3.16, 4.05, 2.28 and 3.34 W/m2, respectively. Harvest occurred 2 or 24 h post-treatment; and methanol/water or ethanol/water (70%, v/v extracts were prepared. Seven glucosinolates and 22 phenolics were identified. Ethanol extracts showed higher levels of certain glucosinolates such as glucoraphanin, whereas methanol extracts showed slight higher levels of phenolics. The highest glucosinolate accumulation occurred 24 h after UVBH treatment, increasing 4-methoxy-glucobrassicin, glucobrassicin and glucoraphanin by ~170, 78 and 73%, respectively. Furthermore, UVAL radiation and harvest 2 h afterwards accumulated gallic acid hexoside I (~14%, 4-O-caffeoylquinic acid (~42%, gallic acid derivative (~48% and 1-sinapoyl-2,2-diferulolyl-gentiobiose (~61%. Increases in sinapoyl malate (~12%, gallotannic acid (~48% and 5-sinapoyl-quinic acid (~121% were observed with UVBH Results indicate that UV-irradiated broccoli sprouts could be exploited as a functional food for fresh consumption or as a source of bioactive phytochemicals with potential industrial applications.

  2. In-chain neutral hydrocarbon loss from crocin apocarotenoid ester glycosides and the crocetin aglycon (Crocus sativus L.) by ESI-MS(n) (n=2, 3).

    Science.gov (United States)

    Pittenauer, Ernst; Koulakiotis, Nikolaos Stavros; Tsarbopoulos, Anthony; Allmaier, Guenter

    2013-12-01

    The stigmas of Crocus sativus L. have been used as spice and colorant agent (i.e. saffron) for more than 4000 years. For an updated structural investigation of the aglycon present in the glycosylated crocetin apocarotenoids (i.e. crocins), seven representative derivatives ranging from one up to five glucosyl-residues with a maximum number of three monosaccharides per glycosylation site (glucose, gentiobiose, gentiotriose and neapolitanose) were isolated and purified by high-performance liquid chromatography. The compounds selected for further mass spectrometric investigation include glucosyl-, bis-glucosyl-, gentiobiosyl-, gentiobiosyl-glucosyl-, bis-gentiobiosyl-, gentiobiosyl-gentiotriosyl- and gentiobiosyl-neapolitanosyl-crocetin. Electrospray ionization in combination with low-energy collision-induced dissociation/tandem mass spectrometry of sodiated crocin precursor ions utilizing either a 3D-ion trap (MS(n) , n = 2, 3) or a QqTOF instrument, with the latter providing accurate mass determination with an accuracy of ±1-3 ppm or better at a resolution of 10,000 (full width at half maximum), was used. Major fragmentation pathways included loss of either one or two carbohydrate substituents leading to the sodiated aglycon without interglycosidic bond cleavage during in MS(2) -experiments. All sodiated precursor ions and major product ions were accompanied by a loss of 92 Da, which was elucidated as C7 H8 -loss from the aglycon by skeletal rearrangement via an eight-membered transition state as previously described for intact C40-carotenoids.

  3. Characterization of Ion Contents and Metabolic Responses to Salt Stress of Different Arabidopsis AtHKT1;1 Genotypes and Their Parental Strains

    Institute of Scientific and Technical Information of China (English)

    Camilla B.Hill; Deepa Jha; Antony Bacic; Mark Tester; Ute Roessner

    2013-01-01

    Plants employ several strategies to maintain cellular ion homeostasis under salinity stress,including mediating ion fluxes by transmembrane transport proteins and adjusting osmotic pressure by accumulating osmolytes.The HKT (high-affinity potassium transporter) gene family comprises Na+ and Na+/K+ transporters in diverse plant species,with HKT1;1 as the only member in Arabidopsis thaliana.Cell-type-specific overexpression of AtHKT1;1 has been shown to prevent shoot Na+ overaccumulation under salinity stress.Here,we analyzed a broad range of metabolites and elements in shoots and roots of different AtHKT1;1 genotypes and their parental strains before and after salinity stress,revealing a reciprocal relationship of metabolite differences between an AtHKT1;1 knockout line (hktl;1) and the AtHKT1;1 overexpressing lines (E2586 UASGAL4:HKT1;1 and J2731*UASGAL4:HKT1;1).Although levels of root sugars were increased after salt stress in both AtHKT1;1 overexpressing lines,E2586 UASGAL4:HKT1;1 showed higher accumulation of the osmoprotectants trehalose,gentiobiose,and melibiose,whereas J2731*UASGAL4:HKT1;1 showed higher levels of sucrose and raffinose,compared with their parental lines,respectively.In contrast,the knockout line hktl;1 showed strong increases in the levels of the tricarboxylic acid (TCA) cycle intermediates in the shoots after salt treatment.This coincided with a significant depletion of sugars,suggesting that there is an increased rate of carbon influx into the TCA cycle at a constant rate of C-efflux from the cycle,which might be needed to support plant survival during salt stress.Using correlation analysis,we identified associations between the Na+ content and several sugars,suggesting that regulation of sugar metabolism is important in plant responses to salinity stress.

  4. Extraction, partial characterization, and storage stability of β-glucosidase from propolis.

    Science.gov (United States)

    Zhang, Cui-Ping; Zheng, Huo-Qing; Hu, Fu-Liang

    2011-01-01

    Extraction and assay conditions for β-glucosidase from propolis were optimized. Highest enzyme activity was obtained in a citric acid-disodium hydrogen phosphate buffer at pH 6.0 with 2.5% insoluble polyvinylpyrrolidone at incubation temperature of 57 °C. β-Glucosidase activities were found in all freshly harvested propolis while β-glucosidase activities were scarcely present in the randomly bought propolis. Propolis was stored at -20 °C and 4 °C for 3 mo with almost no loss of β-glucosidase activity, but at room temperature the activity decreased exponentially with the increase of storage time. These results indicated that the activity of β-glucosidase could be a candidate for propolis-freshness index. β-Glucosidase from propolis was capable of hydrolyzing p-nitrophenyl-β-D-glucoside and p-nitrophenyl-β-D-galactoside, but lacked activity toward p-nitrophenyl-β-D-glucuronide, p-nitrophenyl-β-D-cellobioside, amygdalin, cellobiose, and gentiobiose. These results were consistent with the hypothesis that flavonoid glucosides were hydrolyzed by β-glucosidase during propolis collection and processing and provided a possible explanation for why some flavonoid biosides (that is, rutin and isorhamnetin-3-O-rutinoside) exist in propolis. Practical Application: β-Glucosidase activity was detected and partial characterization of the enzyme was determined in propolis. The enzyme activity decreased exponentially with the increase of storage time at room temperature, which suggested that the activity of β-glucosidase could be regarded as a freshness index of propolis. The research will be useful for studying the chemical constituents of propolis.

  5. Isolation and characterization of lactic acid bacteria strains with ornithine producing capacity from natural sea salt.

    Science.gov (United States)

    Yu, Jin-Ju; Oh, Suk-Heung

    2010-08-01

    Two lactic acid bacteria (LAB) having ornithine-producing capacity were isolated from Korean natural sea salt. They were Gram-positive, short rod-type bacteria, and able to grow anaerobically with CO(2) production. The isolates grew well on MRS broth at 30-37 degrees C and a pH of 6.5-8.0. The optimum temperature and pH for growth are 37 degrees C and pH 7.0. The isolates fermented D-ribose, D-galactose, D-lactose, D-maltose, Dcellobiose, D-tagatose, D-trehalose, sucrose, D-melezitose, gentiobiose, D-glucose but not D-melibiose, inositol, and L-sorbose. The 16S rDNA sequences of the two isolates showed 99.5% and 99.6% homology with the Weissella koreensis S5623 16S rDNA (Access no. AY035891). They were accordingly identified and named as Weissella koreensis MS1-3 and Weissella koreensis MS1-14, and produced intracellular ornithine at levels of 72 mg/100 g cell F.W. and 105 mg/100 g cell F.W. and extracellular ornithine at levels of 4.5 mg/100 ml and 4.6 mg/100 ml medium, respectively, by culturing in MRS broth supplemented with 1% arginine. High cell growth was maintained in MRS broth with a NaCl concentration of 0-6%. These results show for the first time that Korean natural sea salts contain lactic acid bacteria Weissella koreensis strains having ornithine producing capacity.

  6. Purification, gene cloning, and biochemical characterization of a β-glucosidase capable of hydrolyzing sesaminol triglucoside from Paenibacillus sp. KB0549.

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    Arun Nair

    Full Text Available The triglucoside of sesaminol, i.e., 2,6-O-di(β-D-glucopyranosyl-β-D- glucopyranosylsesaminol (STG, occurs abundantly in sesame seeds and sesame oil cake and serves as an inexpensive source for the industrial production of sesaminol, an anti-oxidant that displays a number of bioactivities beneficial to human health. However, STG has been shown to be highly resistant to the action of β-glucosidases, in part due to its branched-chain glycon structure, and these circumstances hampered the efficient utilization of STG. We found that a strain (KB0549 of the genus Paenibacillus produced a novel enzyme capable of efficiently hydrolyzing STG. This enzyme, termed PSTG, was a tetrameric protein consisting of identical subunits with an approximate molecular mass of 80 kDa. The PSTG gene was cloned on the basis of the partial amino acid sequences of the purified enzyme. Sequence comparison showed that the enzyme belonged to the glycoside hydrolase family 3, with significant similarities to the Paenibacillus glucocerebrosidase (63% identity and to Bgl3B of Thermotoga neapolitana (37% identity. The recombinant enzyme (rPSTG was highly specific for β-glucosidic linkage, and k cat and k cat/K m values for the rPSTG-catalyzed hydrolysis of p-nitrophenyl-β-glucopyraniside at 37°C and pH 6.5 were 44 s(-1 and 426 s(-1 mM(-1, respectively. The specificity analyses also revealed that the enzyme acted more efficiently on sophorose than on cellobiose and gentiobiose. Thus, rPSTG is the first example of a β-glucosidase with higher reactivity for β-1,2-glucosidic linkage than for β-1,4- and β-1,6-glucosidic linkages, as far as could be ascertained. This unique specificity is, at least in part, responsible for the enzyme's ability to efficiently decompose STG.

  7. Metabolic Regulation of Carotenoid-Enriched Golden Rice Line.

    Science.gov (United States)

    Gayen, Dipak; Ghosh, Subhrajyoti; Paul, Soumitra; Sarkar, Sailendra N; Datta, Swapan K; Datta, Karabi

    2016-01-01

    Vitamin A deficiency (VAD) is the leading cause of blindness among children and is associated with high risk of maternal mortality. In order to enhance the bioavailability of vitamin A, high carotenoid transgenic golden rice has been developed by manipulating enzymes, such as phytoene synthase (psy) and phytoene desaturase (crtI). In this study, proteome and metabolite analyses were carried out to comprehend metabolic regulation and adaptation of transgenic golden rice after the manipulation of endosperm specific carotenoid pathways. The main alteration was observed in carbohydrate metabolism pathways of the transgenic seeds. The 2D based proteomic studies demonstrated that carbohydrate metabolism-related enzymes, such as pullulanase, UDP-glucose pyrophosphorylase, and glucose-1-phosphate adenylyltransferase, were primarily up-regulated in transgenic rice seeds. In addition, the enzyme PPDK was also elevated in transgenic seeds thus enhancing pyruvate biosynthesis, which is the precursor in the carotenoids biosynthetic pathway. GC-MS based metabolite profiling demonstrated an increase in the levels of glyceric acid, fructo-furanose, and galactose, while decrease in galactonic acid and gentiobiose in the transgenic rice compared to WT. It is noteworthy to mention that the carotenoid content, especially β-carotene level in transgenic rice (4.3 μg/g) was significantly enhanced. The present study highlights the metabolic adaptation process of a transgenic golden rice line (homozygous T4 progeny of SKBR-244) after enhancing carotenoid biosynthesis. The presented information would be helpful in the development of crops enriched in carotenoids by expressing metabolic flux of pyruvate biosynthesis.

  8. Metabolic regulation of carotenoid-enriched Golden rice line

    Directory of Open Access Journals (Sweden)

    Dipak Gayen

    2016-10-01

    Full Text Available Vitamin A deficiency (VAD is the leading cause of blindness among children and is associated with high risk of maternal mortality. In order to enhance the bioavailability of vitamin A, high carotenoid transgenic golden rice has been developed by manipulating enzymes, such as phytoene synthase (psy and phytoene desaturase (crtI. In this study, proteome and metabolite analyses were carried out to comprehend metabolic regulation and adaptation of transgenic golden rice after the manipulation of endosperm specific carotenoid pathways. The main alteration was observed in carbohydrate metabolism pathways of the transgenic seeds. The 2D based proteomic studies demonstrated that carbohydrate metabolism-related enzymes, such as pullulanase, UDP-glucose pyrophosphorylase and glucose-1-phosphate adenylyl transferase, were primarily up-regulated in transgenic rice seeds. In addition, the enzyme PPDK was also elevated in transgenic seeds thus enhancing pyruvate biosynthesis, which is the precursor in the carotenoids biosynthetic pathway. GC-MS based metabolite profiling demonstrated an increase in the levels of glyceric acid, fructo-furanose, and galactose, while decrease in galactonic acid and gentiobiose in the transgenic rice compared to WT. It is noteworthy to mention that the carotenoid content, especially β-carotene level in transgenic rice (4.3 µg/g was significantly enhanced. The present study highlights the metabolic adaptation process of a transgenic golden rice line (homozygous T4 progeny of SKBR-244 after enhancing carotenoid biosynthesis. The presented information would be helpful in the development of crops enriched in carotenoids by expressing metabolic flux of pyruvate biosynthesis.

  9. Catalytic properties and mode of action of endo-(1-->3)-beta-D-glucanase and beta-D-glucosidase from the marine mollusk Littorina kurila.

    Science.gov (United States)

    Pesentseva, Maria S; Kusaykin, Mikhail I; Anastyuk, Stanislav D; Sova, Victoria V; Zvyagintseva, Tatyana N

    2008-09-22

    A complex of the enzymes from the liver of the marine mollusk Littorina kurila that hydrolyzes laminaran was investigated. Two (1-->3)-beta-d-glucanases (G-I and G-II) were isolated. The molecular mass of G-I as estimated by gel-permeation chromatography and SDS-PAGE analysis was 32 and 40kDa, respectively. The G-II molecular mass according to SDS-PAGE analysis was about 200kDa. The pH optimum for both G-I and G-II was pH 5.4. The G-I had narrow substrate specificity and hydrolyzed only the (1-->3)-beta-d-glucosidic bonds in the mixed (1-->3),(1-->6)- and (1-->3),(1-->4)-beta-d-glucans down to glucose and glucooligosaccharides. This enzyme acted with retention of the anomeric configuration and catalyzed a transglycosylation reaction. G-I was classified as the glucan endo-(1-->3)-beta-d-glucosidase (EC 3.2.1.39). G-II exhibited both exo-glucanase and beta-d-glucoside activities. This enzyme released from the laminaran glucose as a single product, but retained the anomeric center configuration and possessed transglycosylation activity. The hydrolysis rate of glucooligosaccharides by G-I decreased with an increase of the substrate's degree of polymerization. In addition to (1-->3)-beta-d-glucanase activity, the enzyme had the ability to hydrolyze p-nitrophenyl beta-d-glucoside and beta-d-glucobioses: laminaribiose, gentiobiose, and cellobiose, with the rate ratio of 50:12:1. G-II may correspond to beta-d-glucoside glucohydrolase (EC 3.2.1.21).

  10. Pantoea gaviniae sp. nov. and Pantoea calida sp. nov., isolated from infant formula and an infant formula production environment.

    Science.gov (United States)

    Popp, Alexandra; Cleenwerck, Ilse; Iversen, Carol; De Vos, Paul; Stephan, Roger

    2010-12-01

    Five Gram-negative, facultatively anaerobic, non-spore-forming, coccoid rod-shaped bacterial isolates were obtained from infant formula and an infant formula production environment and were investigated by use of a polyphasic taxonomic study. Biochemical tests and partial rpoB gene sequence analysis of the five isolates revealed that they formed two distinct groups in the family Enterobacteriaceae, closely related to several species of the genera Pantoea and Erwinia, which indicated a phylogenetic position within the genus Pantoea or the genus Erwinia. Multilocus sequence analysis of concatenated partial atpD, gyrB, infB and rpoB gene sequences of two of the isolates suggested that they represented two novel species of the genus Pantoea, phylogenetically related most closely to Pantoea septica. The five isolates had general characteristics consistent with those of the genus Pantoea, and DNA-DNA hybridizations between two representatives and the type strains of their phylogenetically closest relatives based on comparative 16S rRNA gene sequence analysis showed that the isolates represented two novel genospecies. These two genospecies could be differentiated from each other based on fermentation of galacturonate, sorbitol and potassium 5-ketogluconate. They could be differentiated from phylogenetically related Pantoea species based on their ability to ferment lactose and to utilize β-gentiobiose and raffinose, their inability to ferment or utilize d-arabitol, and their inability to produce indole. On the basis of the results obtained, the five isolates are considered to represent two novel species of the genus Pantoea, for which the names Pantoea gaviniae sp. nov. (type strain A18/07(T) =LMG 25382(T) =DSM 22758(T)) and Pantoea calida sp. nov. (type strain 1400/07(T) =LMG 25383(T) =DSM 22759(T)) are proposed.

  11. Functional and Structural Analysis of a β-Glucosidase Involved in β-1,2-Glucan Metabolism in Listeria innocua.

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    Masahiro Nakajima

    Full Text Available Despite the presence of β-1,2-glucan in nature, few β-1,2-glucan degrading enzymes have been reported to date. Recently, the Lin1839 protein from Listeria innocua was identified as a 1,2-β-oligoglucan phosphorylase. Since the adjacent lin1840 gene in the gene cluster encodes a putative glycoside hydrolase family 3 β-glucosidase, we hypothesized that Lin1840 is also involved in β-1,2-glucan dissimilation. Here we report the functional and structural analysis of Lin1840. A recombinant Lin1840 protein (Lin1840r showed the highest hydrolytic activity toward sophorose (Glc-β-1,2-Glc among β-1,2-glucooligosaccharides, suggesting that Lin1840 is a β-glucosidase involved in sophorose degradation. The enzyme also rapidly hydrolyzed laminaribiose (β-1,3, but not cellobiose (β-1,4 or gentiobiose (β-1,6 among β-linked gluco-disaccharides. We determined the crystal structures of Lin1840r in complexes with sophorose and laminaribiose as productive binding forms. In these structures, Arg572 forms many hydrogen bonds with sophorose and laminaribiose at subsite +1, which seems to be a key factor for substrate selectivity. The opposite side of subsite +1 from Arg572 is connected to a large empty space appearing to be subsite +2 for the binding of sophorotriose (Glc-β-1,2-Glc-β-1,2-Glc in spite of the higher Km value for sophorotriose than that for sophorose. The conformations of sophorose and laminaribiose are almost the same on the Arg572 side but differ on the subsite +2 side that provides no interaction with a substrate. Therefore, Lin1840r is unable to distinguish between sophorose and laminaribiose as substrates. These results provide the first mechanistic insights into β-1,2-glucooligosaccharide recognition by β-glucosidase.

  12. Mining the Sinorhizobium meliloti transportome to develop FRET biosensors for sugars, dicarboxylates and cyclic polyols.

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    Alexandre Bourdès

    Full Text Available Förster resonance energy transfer (FRET biosensors are powerful tools to detect biologically important ligands in real time. Currently FRET bisosensors are available for twenty-two compounds distributed in eight classes of chemicals (two pentoses, two hexoses, two disaccharides, four amino acids, one nucleobase, two nucleotides, six ions and three phytoestrogens. To expand the number of available FRET biosensors we used the induction profile of the Sinorhizobium meliloti transportome to systematically screen for new FRET biosensors.Two new vectors were developed for cloning genes for solute-binding proteins (SBPs between those encoding FRET partner fluorescent proteins. In addition to a vector with the widely used cyan and yellow fluorescent protein FRET partners, we developed a vector using orange (mOrange2 and red fluorescent protein (mKate2 FRET partners. From the sixty-nine SBPs tested, seven gave a detectable FRET signal change on binding substrate, resulting in biosensors for D-quinic acid, myo-inositol, L-rhamnose, L-fucose, β-diglucosides (cellobiose and gentiobiose, D-galactose and C4-dicarboxylates (malate, succinate, oxaloacetate and fumarate. To our knowledge, we describe the first two FRET biosensor constructs based on SBPs from Tripartite ATP-independent periplasmic (TRAP transport systems.FRET based on orange (mOrange2 and red fluorescent protein (mKate2 partners allows the use of longer wavelength light, enabling deeper penetration of samples at lower energy and increased resolution with reduced back-ground auto-fluorescence. The FRET biosensors described in this paper for four new classes of compounds; (i cyclic polyols, (ii L-deoxy sugars, (iii β-linked disaccharides and (iv C4-dicarboxylates could be developed to study metabolism in vivo.

  13. Lactobacillus herbarum sp. nov., a species related to Lactobacillus plantarum.

    Science.gov (United States)

    Mao, Yuejian; Chen, Meng; Horvath, Philippe

    2015-12-01

    Strain TCF032-E4 was isolated from a traditional Chinese fermented radish. It shares >99% 16S rRNA sequence identity with L. plantarum, L. pentosus and L. paraplantarum. This strain can ferment ribose, galactose, glucose, fructose, mannose, mannitol, N-acetylglucosamine, amygdalin, arbutin, salicin, cellobiose, maltose, lactose, melibiose, trehalose and gentiobiose. It cannot ferment sucrose, which can be used by L. pentosus, L. paraplantarum, L. fabifermentans, L. xiangfangensis and L. mudanjiangensis, as well as most of the L. plantarum strains (88.7%). TCF032-E4 cannot grow at temperature above 32 °C. This strain shares 78.2-83.6% pheS (phenylalanyl-tRNA synthetase alpha subunit) and 89.5-94.9% rpoA (RNA polymerase alpha subunit) sequence identity with L. plantarum, L. pentosus, L. paraplantarum, L. fabifermentans, L. xiangfangensis and L. mudanjiangensis. These results indicate that TCF032-E4 represents a distinct species. This hypothesis was further confirmed by whole-genome sequencing and comparison with available genomes of related species. The draft genome size of TCF032-E4 is approximately 2.9 Mb, with a DNA G+C content of 43.5 mol%. The average nucleotide identity (ANI) between TCF032-E4 and related species ranges from 79.0 to 81.1%, the highest ANI value being observed with L. plantarum subsp. plantarum ATCC 14917T. A novel species, Lactobacillus herbarum sp. nov., is proposed with TCF032-E4T ( = CCTCC AB2015090T = DSM 100358T) as the type strain.

  14. Caloranaerobacter ferrireducens sp. nov., an anaerobic, thermophilic, iron (III)-reducing bacterium isolated from deep-sea hydrothermal sulfide deposits.

    Science.gov (United States)

    Zeng, Xiang; Zhang, Zhao; Li, Xi; Jebbar, Mohamed; Alain, Karine; Shao, Zongze

    2015-06-01

    A thermophilic, anaerobic, iron-reducing bacterium (strain DY22619T) was isolated from a sulfide sample collected from an East Pacific Ocean hydrothermal field at a depth of 2901 m. Cells were Gram-stain-negative, motile rods (2-10 µm in length, 0.5 µm in width) with multiple peritrichous flagella. The strain grew at 40-70 °C inclusive (optimum 60 °C), at pH 4.5-8.5 inclusive (optimum pH 7.0) and with sea salts concentrations of 1-10 % (w/v) (optimum 3 % sea salts) and NaCl concentrations of 1.5-5.0 % (w/v) (optimum 2.5 % NaCl). Under optimal growth conditions, the generation time was around 55 min. The isolate was an obligate chemoorganoheterotroph, utilizing complex organic compounds, amino acids, carbohydrates and organic acids including peptone, tryptone, beef extract, yeast extract, alanine, glutamate, methionine, threonine, fructose, mannose, galactose, glucose, palatinose, rhamnose, turanose, gentiobiose, xylose, sorbose, pyruvate, tartaric acid, α-ketobutyric acid, α-ketovaleric acid, galacturonic acid and glucosaminic acid. Strain DY22619T was strictly anaerobic and facultatively dependent on various forms of Fe(III) as an electron acceptor: insoluble forms and soluble forms. It did not reduce sulfite, sulfate, thiosulfate or nitrate. The genomic DNA G+C content was 29.0 mol%. Phylogenetic 16S rRNA gene sequence analyses revealed that the closest relative of strain DY22619T was Caloranaerobacter azorensis MV1087T, sharing 97.41 % 16S rRNA gene sequence similarity. On the basis of physiological distinctness and phylogenetic distance, the isolate is considered to represent a novel species of the genus Caloranaerobacter, for which the name Caloranaerobacterhttp://dx.doi.org/10.1601/nm.4081ferrireducens sp. nov. is proposed. The type strain is DY22619T ( = JCM 19467T = DSM 27799T = MCCC1A06455T).

  15. Rebaudioside A and Rebaudioside D bitterness do not covary with Acesulfame K bitterness or polymorphisms in TAS2R9 and TAS2R31.

    Science.gov (United States)

    Allen, Alissa L; McGeary, John E; Hayes, John E

    2013-09-01

    In order to reduce calories in foods and beverages, the food industry routinely uses non-nutritive sweeteners. Unfortunately, many are synthetically derived, and many consumers have a strong preference for natural sweeteners, irrespective of the safety data on synthetic non-nutritive sweeteners. Additionally, many non-nutritive sweeteners elicit aversive side tastes such as bitter and metallic in addition to sweetness. Bitterness thresholds of acesulfame-K (AceK) and saccharin are known to vary across bitter taste receptors polymorphisms in TAS2R31. RebA has shown to activate hTAS2R4 and hTAS2R14 in vitro. Here we examined bitterness and sweetness perception of natural and synthetic non-nutritive sweeteners. In a follow-up to a previous gene-association study, participants (n=122) who had been genotyped previously rated sweet, bitter and metallic sensations from rebaudioside A (RebA), rebaudioside D (RebD), aspartame, sucrose and gentiobiose in duplicate in a single session. For comparison, we also present sweet and bitter ratings of AceK collected in the original experiment for the same participants. At similar sweetness levels, aspartame elicited less bitterness than RebD, which was significantly less bitter than RebA. The bitterness of RebA and RebD showed wide variability across individuals, and bitterness ratings for these compounds were correlated. However, RebA and RebD bitterness did not covary with AceK bitterness. Likewise, single nucleotide polymorphisms (SNPs) shown previously to explain variation in the suprathreshold bitterness of AceK (rs3741845 in TAS2R9 and rs10772423 in TAS2R31) did not explain variation in RebA and RebD bitterness. Because RebA activates hT2R4 and hT2R14, a SNP in TAS2R4 previously associated with variation in bitterness perception was included here; there are no known functional SNPs for TAS2R14. In present data, a putatively functional SNP (rs2234001) in TAS2R4 did not explain variation in RebA or RebD bitterness. Collectively