Sample records for yeast extract sucrose

  1. Glucose and sucrose: hazardous fast-food for industrial yeast?

    E-print Network

    Glucose and sucrose: hazardous fast-food for industrial yeast? Kevin J. Verstrepen1,2 , Dirk 197, Glen Osmond, Adelaide SA-5064, Australia Yeast cells often encounter a mixture of different resist- ance. In an industrial context, these effects lead to several yeast-related problems

  2. Glucose and sucrose: hazardous fast-food for industrial yeast?

    Microsoft Academic Search

    Kevin J. Verstrepen; Dirk Iserentant; Philippe Malcorps; Guy Derdelinckx; Patrick Van Dijck; Joris Winderickx; Isak S. Pretorius; Johan M. Thevelein; Freddy R. Delvaux

    2004-01-01

    Yeast cells often encounter a mixture of different carbohydrates in industrial processes. However, glucose and sucrose are always consumed first. The presence of these sugars causes repression of gluconeogenesis, the glyoxylate cycle, respiration and the uptake of less- preferred carbohydrates. Glucose and sucrose also trigger unexpected, hormone-like effects, including the activation of cellular growth, the mobilization of storage compounds and

  3. Supplementary Figure 1: Design of experiment and sucrose metabolism in yeast. Sucrose is hydrolyzed by the enzyme invertase in the periplasmic space between the

    E-print Network

    van Oudenaarden, Alexander

    Supplementary Figure 1: Design of experiment and sucrose metabolism in yeast. Sucrose is hydrolyzed hydrolyzes any sucrose that is directly imported by the non-specific AGT1 permease3 . We find that an AGT1

  4. 21 CFR 184.1983 - Bakers yeast extract.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Bakers yeast extract. 184.1983 Section 184.1983 Food...Substances Affirmed as GRAS § 184.1983 Bakers yeast extract. (a) Bakers yeast extract is the food ingredient resulting...

  5. 21 CFR 184.1983 - Bakers yeast extract.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 2010-04-01 2009-04-01 true Bakers yeast extract. 184.1983 Section 184.1983 Food...Substances Affirmed as GRAS § 184.1983 Bakers yeast extract. (a) Bakers yeast extract is the food ingredient resulting...

  6. 21 CFR 184.1983 - Bakers yeast extract.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Bakers yeast extract. 184.1983 Section 184.1983 Food...Substances Affirmed as GRAS § 184.1983 Bakers yeast extract. (a) Bakers yeast extract is the food ingredient resulting...

  7. 21 CFR 184.1983 - Bakers yeast extract.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Bakers yeast extract. 184.1983 Section 184.1983 Food...Substances Affirmed as GRAS § 184.1983 Bakers yeast extract. (a) Bakers yeast extract is the food ingredient resulting...

  8. Sucrose Utilization in Budding Yeast as a Model for the Origin of Undifferentiated Multicellularity

    PubMed Central

    H. Koschwanez, John; R. Foster, Kevin; W. Murray, Andrew

    2011-01-01

    We use the budding yeast, Saccharomyces cerevisiae, to investigate one model for the initial emergence of multicellularity: the formation of multicellular aggregates as a result of incomplete cell separation. We combine simulations with experiments to show how the use of secreted public goods favors the formation of multicellular aggregates. Yeast cells can cooperate by secreting invertase, an enzyme that digests sucrose into monosaccharides, and many wild isolates are multicellular because cell walls remain attached to each other after the cells divide. We manipulate invertase secretion and cell attachment, and show that multicellular clumps have two advantages over single cells: they grow under conditions where single cells cannot and they compete better against cheaters, cells that do not make invertase. We propose that the prior use of public goods led to selection for the incomplete cell separation that first produced multicellularity. PMID:21857801

  9. 21 CFR 172.590 - Yeast-malt sprout extract.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Drugs 3 2010-04-01 2009-04-01 true Yeast-malt sprout extract. 172.590 Section 172...Flavoring Agents and Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout extract, as described in this...

  10. 21 CFR 172.590 - Yeast-malt sprout extract.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 3 2013-04-01 2013-04-01 false Yeast-malt sprout extract. 172.590 Section 172...Flavoring Agents and Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout extract, as described in this...

  11. 21 CFR 172.590 - Yeast-malt sprout extract.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 3 2012-04-01 2012-04-01 false Yeast-malt sprout extract. 172.590 Section 172...Flavoring Agents and Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout extract, as described in this...

  12. 21 CFR 172.590 - Yeast-malt sprout extract.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 3 2011-04-01 2011-04-01 false Yeast-malt sprout extract. 172.590 Section 172...Flavoring Agents and Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout extract, as described in this...

  13. 21 CFR 172.590 - Yeast-malt sprout extract.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 3 2014-04-01 2014-04-01 false Yeast-malt sprout extract. 172.590 Section 172...Flavoring Agents and Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout extract, as described in this...

  14. Production of ethanol by filamentous and yeast-like forms of Mucor indicus from fructose, glucose, sucrose, and molasses.

    PubMed

    Sharifia, Mahnaz; Karimi, Keikhosro; Taherzadeh, Mohammad J

    2008-11-01

    The fungus Mucor indicus is found in this study able to consume glucose and fructose, but not sucrose in fermentation of sugarcane and sugar beet molasses. This might be an advantage in industries which want to selectively remove glucose and fructose for crystallisation of sucrose present in the molasses. On the other hand, the fungus assimilated sucrose after hydrolysis by the enzyme invertase. The fungus efficiently grew on glucose and fructose and produced ethanol in synthetic media or from molasses. The cultivations were carried out aerobically and anaerobically, and manipulated toward filamentous or yeast-like morphology. Ethanol was the major metabolite in all the experiments. The ethanol yield in anaerobic cultivations was between 0.35 and 0.48 g/g sugars consumed, depending on the carbon source and the growth morphology, while a yield of as low as 0.16 g/g was obtained during aerobic cultivation. The yeast-like form of the fungus showed faster ethanol production with an average productivity of 0.90 g/l h from glucose, fructose and inverted sucrose, than the filamentous form with an average productivity of 0.33 g/l h. The biomass of the fungus was also analyzed with respect to alkali-insoluble material (AIM), chitin, and chitosan. The biomass of the fungus contained per g maximum 0.217 g AIM and 0.042 g chitosan in yeast-like cultivation under aerobic conditions. PMID:18712551

  15. Isomaltulose production via yeast surface display of sucrose isomerase from Enterobacter sp. FMB-1 on Saccharomyces cerevisiae.

    PubMed

    Lee, Gil-Yong; Jung, Jong-Hyun; Seo, Dong-Ho; Hansin, Jantra; Ha, Suk-Jin; Cha, Jaeho; Kim, Yong-Sung; Park, Cheon-Seok

    2011-10-01

    The gene encoding sucrose isomerase from Enterobacter sp. FMB-1 species (ESI) was displayed on the cell surface of Saccharomyces cerevisiae EBY100 using a glycosylphosphatidylinositol (GPI) anchor attachment signal sequence. Fluorescence activated cell sorting (FACS) analysis and immunofluorescence microscopy confirmed the localization of ESI on the yeast cell surface. The displayed ESI (dESI) was stable at a broad range of temperatures (35-55 °C) and pHs (pH 5-7) with optimal temperature and pH at 45 °C and pH 7.0, respectively. In addition, the thermostability of the dESI was significantly enhanced compared with the recombinant ESI expressed in Escherichia coli. Biotransformation of sucrose to isomaltulose was observed in various ranges of substrate concentrations (50-250 mM) with a 6.4-7.4% conversion yield. It suggested that the bioconversion of sucrose to isomaltulose can be successfully performed by the dESI on the surface of host S. cerevisiae. PMID:21803574

  16. Charcoal-Yeast Extract Agar: Primary Isolation Mediumfor Legionella pneumophila

    Microsoft Academic Search

    JAMES C. FEELEY; ROBERT J. GIBSON; GEORGE W. GORMAN; NANCY C. LANGFORD; J. KAMILE RASHEED; DON C. MACKEL; WILLIAM B. BAINE

    1979-01-01

    Charcoal-yeast extract agar isa new bacteriological mediumthatsupports excellent growth oftheLegionella pneumophila. Itresults frommodifications madeinan existing L.pneumophila medium,F-Gagar.Yeastextract, instead of an acidhydrolysate ofcasein, servesastheprotein source.Beefextractives and starch are notadded. Activated charcoal (Norit A or Norit SG)isincluded at 0.20%(wt\\/vol). Comparison ofcharcoal-yeast extract andF-Gagars showedthat a greater numberofcolony-forming units ofL.pneumophila was recovered from astandardized tissue inoculum on charcoal-yeast extract agar(4.35 x 106colony- forning

  17. Spray Drying of Extracts from Red Yeast Fermentation Broth

    Microsoft Academic Search

    C. C. C. Teixeira; G. A. Teixeira; L. A. P. Freitas

    2011-01-01

    Red yeast rice is a pigmented material that is traditionally used in Asia as a food colorant. In addition to food applications, red yeast rice is known in traditional Chinese medicine for its therapeutic actions. The aim of this work was to study the quality interactions during spray drying of extracts from the Monascus ruber van Tiegham fermentation broth. The

  18. Quality assessment of lager brewery yeast samples and strains using barley malt extracts with anti-yeast activity.

    PubMed

    van Nierop, Sandra N E; Axcell, Barry C; Cantrell, Ian C; Rautenbach, Marina

    2009-04-01

    Membrane active anti-yeast compounds, such as antimicrobial peptides and proteins, cause yeast membrane damage which is likely to affect yeast vitality and fermentation performance, parameters which are notoriously difficult to analyse. In this work the sensitivity of lager brewery yeast strains towards barley malt extracts with anti-yeast activity was assessed with an optimised assay. It was found that yeast, obtained directly from a brewery, was much more sensitive towards the malt extracts than the same yeast strain propagated in the laboratory. Sensitivity to the malt extracts increased during the course of a laboratory scale fermentation when inoculated with brewery yeast. As the assay was able to differentiate yeast samples with different histories, it shows promise as a yeast quality assay measuring the yeast's ability to withstand stress which can be equated to vitality. The assay was also able to differentiate between different lager yeast strains of Saccharomyces cerevisiae propagated in the laboratory when challenged with a number of malt extracts of varying anti-yeast activity. The assessment of yeast strains in the presence of malt extracts will lead to the identification of yeast strains with improved quality/vitality that can withstand malt-associated anti-yeast activity during brewery fermentations. PMID:19171262

  19. 40 CFR 180.1246 - Yeast Extract Hydrolysate from Saccharomyces cerevisiae: exemption from the requirement of a...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Yeast Extract Hydrolysate from Saccharomyces...Exemptions From Tolerances § 180.1246 Yeast Extract Hydrolysate from Saccharomyces...for residues of the biochemical pesticide Yeast Extract Hydrolysate from...

  20. 40 CFR 180.1246 - Yeast Extract Hydrolysate from Saccharomyces cerevisiae: exemption from the requirement of a...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Yeast Extract Hydrolysate from Saccharomyces...Exemptions From Tolerances § 180.1246 Yeast Extract Hydrolysate from Saccharomyces...for residues of the biochemical pesticide Yeast Extract Hydrolysate from...

  1. 40 CFR 180.1246 - Yeast Extract Hydrolysate from Saccharomyces cerevisiae: exemption from the requirement of a...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Yeast Extract Hydrolysate from Saccharomyces...Exemptions From Tolerances § 180.1246 Yeast Extract Hydrolysate from Saccharomyces...for residues of the biochemical pesticide Yeast Extract Hydrolysate from...

  2. 40 CFR 180.1246 - Yeast Extract Hydrolysate from Saccharomyces cerevisiae: exemption from the requirement of a...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Yeast Extract Hydrolysate from Saccharomyces...Exemptions From Tolerances § 180.1246 Yeast Extract Hydrolysate from Saccharomyces...for residues of the biochemical pesticide Yeast Extract Hydrolysate from...

  3. 40 CFR 180.1246 - Yeast Extract Hydrolysate from Saccharomyces cerevisiae: exemption from the requirement of a...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Yeast Extract Hydrolysate from Saccharomyces...Exemptions From Tolerances § 180.1246 Yeast Extract Hydrolysate from Saccharomyces...for residues of the biochemical pesticide Yeast Extract Hydrolysate from...

  4. Ameliorative Effect of Hydroethanolic Leaf Extract of Byrsocarpus coccineus in Alcohol- and Sucrose-Induced Hypertension in Rats

    PubMed Central

    Akindele, Abidemi J.; Iyamu, Endurance A.; Dutt, Prabhu; Satti, Naresh K.; Adeyemi, Olufunmilayo O.

    2014-01-01

    Hypertension remains a major health problem worldwide considering the prevalence of morbidity and mortality. Plants remain a reliable source of efficacious and better tolerated drugs and botanicals. This study was designed to investigate the effect of the chemo-profiled hydroethanolic leaf extract of Byrsocarpus coccineus in ethanol- and sucrose-induced hypertension. Groups of rats were treated orally (p.o.) with distilled water (10 ml/kg), ethanol (35%; 3 g/kg), sucrose (5-7%), and B. coccineus (100, 200, and 400 mg/kg), and nifedipine together with ethanol and sucrose separately for 8 weeks. At the end of the treatment period, blood pressure and heart rate of rats were determined. Blood was collected for serum biochemical parameters and lipid profile assessment, and the liver, aorta, kidney, and heart were harvested for estimation of in vivo antioxidants and malondialdehyde (MDA). Results obtained in this study showed that B. coccineus at the various doses administered reduced the systolic, diastolic, and arterial blood pressure elevated by ethanol and sucrose. Also, the extract reversed the reduction in catalase (CAT), reduced glutathione (GSH), glutathione peroxidase (GPx), and superoxide dismutase (SOD) induced by ethanol and sucrose. The level of MDA was reduced compared to the ethanol- and sucrose-induced hypertensive group. With respect to lipid profile, administration of B. coccineus at the various doses reduced the levels of triglycerides, low-density lipoprotein (LDL), cholesterol, and atherogenic indices, compared to the ethanol and sucrose groups. In conclusion the hydroethanolic leaf extract of B. coccineus exerted significant antihypertensive effect and this is probably related to the antioxidant property and improvement of lipid profile observed in this study. PMID:25161923

  5. Mild water stress of Phaseolus vulgaris plants leads to reduced starch synthesis and extractable sucrose phosphate synthase activity

    SciTech Connect

    Vassey, T.L.; Sharkey, T.D. (Univ. of Wisconsin, Madison (USA))

    1989-04-01

    Mild water stress, on the order of {minus}1.0 megapascals xylem water potential, can reduce the rate of photosynthesis and eliminate the inhibition of photosynthesis caused by O{sub 2} in water-stress-sensitive plants such as Phaseolus vulgaris. To investigate the lack of O{sub 2} inhibition of photosynthesis, we measured stromal and cytosolic fructose-1,6-bisphosphatase, sucrose phosphate synthase, and partitioning of newly fixed carbon between starch and sucrose before, during, and after mild water stress. The extractable activity of the fructose bisphosphatases was unaffected by mild water stress. The extractable activity of SPS was inhibited by more than 60% in plants stressed to water potentials of {minus}0.9 megapascals. Water stress caused a decline in the starch/sucrose partitioning ratio indicating that starch synthesis was inhibited more than sucrose synthesis. We conclude that the reduced rate of photosynthesis during water stress is caused by stomatal closure, and that the restriction of CO{sub 2} supply caused by stomatal closure leads to a reduction in the capacity for both starch and sucrose synthesis. This causes the reduced O{sub 2} inhibition and abrupt CO{sub 2} saturation of photosynthesis.

  6. In vitro antimycotic activity of some plant extracts towards yeast and yeast-like strains.

    PubMed

    Turchetti, B; Pinelli, P; Buzzini, P; Romani, A; Heimler, D; Franconi, F; Martini, A

    2005-01-01

    As part of screening aimed at the selection of novel antimycotic compounds of vegetable origin, leaf extracts of Camellia sinensis L., Cupressus sempervirens L. and Pistacia lentiscus L. and the seed extract of Glycine soja Sieb. et Zucc. were tested against yeast and yeast-like species implicated in human mycoses. Of the extracts only those of C. sinensis (obtained from a commercial preparation of green tea) exhibited broad activity towards Candida glabrata, Clavispora lusitatiae, Cryptococcus laurentii, Filobasidiella neoformans, Issatchenkia orientalis, Saccharomyces cerevisiae and Prototheca wickerhamii strains. MICs ranging from 300 to 4800 microg extract/mL (corresponding to 130-2010 microg/mL total polyphenols) were observed. Concentrations of the C. sinensis extract over 25 000 microg/mL caused a rapid decrease of viable cells of Fil. neoformans and its activity was dose-dependent. Tests carried out using the pure polyphenols present in C. sinensis extract composition, showed that only epicatechin-3-O-gallate (ECG) and epigallocatechin-3-O-gallate (EGCG) possess antimycotic activity. PMID:15798996

  7. [Anti-yeast activity of ethanol extracts of Lilium candidum L].

    PubMed

    Mucaji, P; Hudecová, D; Haladová, M; Eisenreichová, E

    2002-11-01

    The paper deals with anti-yeast activity of ethanolic extracts from the flowers and bulbs of Lilium candidum L., Liliaceae, as well as some compounds isolated from these extracts. Several different methods were used for the determination of anti-yeast activity: Lowry method of protein determination, dilution and cultivation method. The extract from the bulbs was shown to be more active than the extract from the flowers, while isolated compounds were inactive against the tested yeasts. PMID:12501491

  8. Malolactic bioconversion using a Oenococcus oeni strain for cider production: effect of yeast extract supplementation

    Microsoft Academic Search

    Mónica Herrero; Luis A. García; Mario Díaz

    2003-01-01

    Yeast extract addition to reconstituted apple juice had a positive impact on the development of the malolactic starter culture used to ensure malolactic fermentation in cider, using active but non-proliferating cells. In this work, the reuse of fermentation lees from cider is proposed as an alternative to the use of commercial yeast extract products. Malolactic enzymatic assays, both in whole

  9. Occurrence and Growth of Yeasts in Yogurts

    PubMed Central

    Suriyarachchi, V. R.; Fleet, G. H.

    1981-01-01

    Yogurts purchased from retail outlets were examined for the presence of yeasts by being plated onto oxytetracycline malt extract agar. Of the 128 samples examined, 45% exhibited yeast counts above 103 cells per g. A total of 73 yeast strains were isolated and identified as belonging to the genera Torulopsis, Kluyveromyces, Saccharomyces, Candida, Rhodotorula, Pichia, Debaryomyces, and Sporobolomyces. Torulopsis candida and Kluyveromyces fragilis were the most frequently isolated species, followed by Saccharomyces cerevisiae, Rhodotorula rubra, Kluyveromyces lactis, and Torulopsis versatilis. The growth of yeasts in yogurts was related to the ability of the yeasts to grow at refrigeration temperatures, to ferment lactose and sucrose, and to hydrolyze milk casein. Most yeast isolates grew in the presence of 100 ?g of sorbate and benzoate preservatives per ml. Higher yeast counts from yogurts were obtained when the yogurts were plated onto oxytetracycline malt extract agar than when they were plated onto acidified malt extract agar. PMID:16345853

  10. Molecular Structure of Sucrose

    NSDL National Science Digital Library

    2002-08-29

    Sucrose is the chemical name of table sugar. It is found in granulated, powdered and brown sugar and molasses, as well as, in a variety of fruits and vegetables. Sucrose is a disaccharide that can be made from the combination of two monosaccarides, glucose and fructose. For production use, sucrose is generally extracted from a sugar cane and then purified and crystallized. Sucrose is the most common sweetener in the modern world, however, including too much of it in a diet does have adverse health effects such obesity caused by the high calorie content.

  11. Fractionation of Phenolic Compounds Extracted from Propolis and Their Activity in the Yeast Saccharomyces cerevisiae

    PubMed Central

    Petelinc, Tanja; Polak, Tomaž; Demšar, Lea; Jamnik, Polona

    2013-01-01

    We have here investigated the activities of Slovenian propolis extracts in the yeast Saccharomyces cerevisiae, and identified the phenolic compounds that appear to contribute to these activities. We correlated changes in intracellular oxidation and cellular metabolic energy in these yeasts with the individual fractions of the propolis extracts obtained following solid-phase extraction. The most effective fraction was further investigated according to its phenolic compounds. PMID:23409133

  12. Fractionation of phenolic compounds extracted from propolis and their activity in the yeast Saccharomyces cerevisiae.

    PubMed

    Petelinc, Tanja; Polak, Tomaž; Demšar, Lea; Jamnik, Polona

    2013-01-01

    We have here investigated the activities of Slovenian propolis extracts in the yeast Saccharomyces cerevisiae, and identified the phenolic compounds that appear to contribute to these activities. We correlated changes in intracellular oxidation and cellular metabolic energy in these yeasts with the individual fractions of the propolis extracts obtained following solid-phase extraction. The most effective fraction was further investigated according to its phenolic compounds. PMID:23409133

  13. Effect of yeast extract on growth kinetics during aerobic biodegradation of chlorobenzoic acids

    SciTech Connect

    Armenante, P.M. [New Jersey Inst. of Tech., Newark, NJ (United States). Dept. of Chemical Engineering, Chemistry, and Environmental Science; Fava, F. [Univ. di Bologna (Italy). Dept. of Applied Chemistry and Material Science; Kafkewitz, D. [Rutgers, The State Univ. of New Jersey, Newark, NJ (United States). Dept. of Biological Sciences

    1995-07-20

    The Monod or Andrews kinetic parameters describing the growth of Pseudomonas sp. CPE2 strain on 2,5-dichlorobenzoic acid and 2-chlorobenzoic acid, and Al-caligenes sp. CPE3 strain on 3,4-dichlorobenzoic acid, 4-chlorobenzoic acid, and 3-chlorobenzoic acid were determined from batch and continuous growth experiments conducted in the presence or absence of yeast extract (50 mg/L). Strain CPE2 displayed inhibitory growth kinetics in the absence of yeast extract and a noninhibitory kinetics in the presence of yeast extract. Similar results were obtained for CPE3. The presence of yeast extract also resulted in a significant increase in the affinity of the strains for the chlorobenzoic acids they degraded.

  14. Strategy for the extraction of yeast DNA from artisan agave must for quantitative PCR analysis.

    PubMed

    Kirchmayr, Manuel Reinhart; Segura-Garcia, Luis Eduardo; Flores-Berrios, Ericka Patricia; Gschaedler, Anne

    2011-11-01

    An efficient method for the direct extraction of yeast genomic DNA from agave must was developed. The optimized protocol, which was based on silica-adsorption of DNA on microcolumns, included an enzymatic cell wall degradation step followed by prolonged lysis with hot detergent. The resulting extracts were suitable templates for subsequent qPCR assays that quantified mixed yeast populations in artisan Mexican mezcal fermentations. PMID:21820955

  15. Accelerated solvent extraction of monacolin K from red yeast rice and purification by high-speed counter-current chromatography

    Microsoft Academic Search

    Yuqin Liu; Xingfeng Guo; Wenjuan Duan; Xiao Wang; Jinhua Du

    2010-01-01

    Monacolin K from red yeast rice was extracted by accelerated solvent extraction (ASE). The effects of various extraction parameters including extraction temperature, static extraction time and cycle index on yield were investigated using a DIONEX ASE 300 system to select the optimal conditions by an orthogonal test design L9 (3)3. The optimum extraction conditions were determined as follows: extraction temperature

  16. 21 CFR 184.1983 - Bakers yeast extract.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...than 10,000 organisms/gram by aerobic plate count. (2) Less than 10 yeasts and molds/gram. (3) Negative for Salmonella, E. coli, coagulase positive Staphylococci, Clostridium perfringens, Clostridium botulinum, or any other...

  17. Combined effect of crude herbal extracts, pH and sucrose on the survival of Candida parapsilosis and Zygosaccharomyces fermentati in orange juice

    Microsoft Academic Search

    Daorin Sukkasem; Tipparat Hongpattarakere

    2007-01-01

    Sukkasem, D., Hongpattarakere, T. and H-Kittikun, A. Combined effect of crude herbal extracts, pH and sucrose on the survival of Candida parapsilosis and Zygosaccharomyces fermentati in orange juice Songklanakarin J. Sci. Technol., 2007, 29(3) : 793-800 The purpose of this study was to evaluate the antimicrobial activity of crude extracts of cinnamon and clove compared with potassium sorbate against food

  18. Kefir-yeast technology: Industrial scale-up of alcoholic fermentation of whey, promoted by raisin extracts, using kefir-yeast granular biomass

    Microsoft Academic Search

    Athanasios A. Koutinas; Ilias Athanasiadis; Argyro Bekatorou; Costas Psarianos; Maria Kanellaki; Nikolaos Agouridis; Georgios Blekas

    2007-01-01

    Industrial scale-up of whey fermentation, promoted by raisin extracts, using free kefir-yeast cells is reported. The fermented whey would be exploited as raw material to produce kefir-like whey-based drinks, potable and fuel alcohol, as well as kefir-yeast biomass for use as baker's yeast. The scale-up process involved the development of a technology transfer scheme from lab-scale experiments to a successive

  19. Chromatin assembly in a yeast whole-cell?extract

    PubMed Central

    Schultz, Michael C.; Hockman, Darren J.; Harkness, Troy A. A.; Garinther, Wendy I.; Altheim, Brent A.

    1997-01-01

    A simple in vitro system that supports chromatin assembly was developed for Saccharomyces cerevisiae. The assembly reaction is ATP-dependent, uses soluble histones and assembly factors, and generates physiologically spaced nucleosomes. We analyze the pathway of histone recruitment into nucleosomes, using this system in combination with genetic methods for the manipulation of yeast. This analysis supports the model of sequential recruitment of H3/H4 tetramers and H2A/H2B dimers into nucleosomes. Using a similar approach, we show that DNA ligase I can play an important role in template repair during assembly. These studies demonstrate the utility of this system for the combined biochemical and genetic analysis of chromatin assembly in yeast. PMID:9256430

  20. Laboratory diagnosis of Acanthamoeba keratitis using buffered charcoal-yeast extract agar

    Microsoft Academic Search

    Rebecca L. Penland; Kirk R. Wilhelmus

    1998-01-01

    PURPOSE: To evaluate the use of buffered charcoal-yeast extract agar for the isolation of Acanthamoeba from clinical specimens.METHODS: We retrospectively reviewed laboratory records of patients with ocular acanthamebic infection from October 1993 to September 1997 to compare the recovery of Acanthamoeba from clinical specimens inoculated onto various media. We then compared the experimental recovery of 10 corneal isolates of Acanthamoeba

  1. Extracting Regulatory Sites from the Upstream Region of Yeast Genes by Computational Analysis of Oligonucleotide Frequencies

    Microsoft Academic Search

    J. van Helden; B. Andre; J. Collado-Vides

    2002-01-01

    We present here a simple and fast method allowing the isolation of DNA binding sites for transcription factors from families of coregulated genes, with results illustrated in Saccharomyces cerevisiae. Although conceptually simple, the algorithm proved efficient for extracting, from most of the yeast regulatory families analyzed, the upstream regulatory sequences which had been previously found by experimental analysis. Furthermore, putative

  2. A single protocol for extraction of gDNA from bacteria and yeast.

    PubMed

    Vingataramin, Laurie; Frost, Eric H

    2015-03-01

    Guanidine thiocyanate breakage of microorganisms has been the standard initial step in genomic DNA (gDNA) extraction of microbial DNA for two decades, despite the requirement for pretreatments to extract DNA from microorganisms other than Gram-negative bacteria. We report a quick and low-cost gDNA extraction protocol called EtNa that is efficient for bacteria and yeast over a broad range of concentrations. EtNa is based on a hot alkaline ethanol lysis. The solution can be immediately centrifuged to yield a crude gDNA extract suitable for PCR, or it can be directly applied to a silica column for purification. PMID:25757544

  3. A rapid and simple method for DNA extraction from yeasts and fungi isolated from Agave fourcroydes

    Microsoft Academic Search

    Raul Tapia-Tussell; Patricia Lappe; Miguel Ulloa; Andrés Quijano-Ramayo; Mirbella Cáceres-Farfán; Alfonso Larqué-Saavedra; Daisy Perez-Brito

    2006-01-01

    A simple and easy protocol for extracting high-quality DNA from different yeast and filamentous fungal species is described.\\u000a This method involves two important steps: first, the disruption of cell walls by mechanical means and freezing; and second,\\u000a the extraction, isolation, and precipitation of genomic DNA. The absorbance ratios (A260\\/A280) obtained ranged from 1.6 to 2.0. The main objective of this

  4. A rapid and simple method for DNA extraction from yeasts and fungi isolated from Agave fourcroydes.

    PubMed

    Tapia-Tussell, Raul; Lappe, Patricia; Ulloa, Miguel; Quijano-Ramayo, Andrés; Cáceres-Farfán, Mirbella; Larqué-Saavedra, Alfonso; Perez-Brito, Daisy

    2006-05-01

    A simple and easy protocol for extracting high-quality DNA from different yeast and filamentous fungal species is described. This method involves two important steps: first, the disruption of cell walls by mechanical means and freezing; and second, the extraction, isolation, and precipitation of genomic DNA. The absorbance ratios (A(260)/A(280)) obtained ranged from 1.6 to 2.0. The main objective of this procedure is to extract pure DNA from yeast and filamentous fungi, including those with high contents of proteins, polysaccharides, and other complex compounds in their cell walls. The yield and quality of the DNAs obtained were suitable for micro/minisatellite primer-polymerase chain reaction (MSP-PCR) fingerprinting as well as for the sequence of the D1/D2 domain of the 26S rDNA. PMID:16691008

  5. Preparation of a ?-glutamylcysteine-enriched yeast extract from a newly developed GSH2-deficient strain.

    PubMed

    Nishiuchi, Hiroaki; Suehiro, Mariko; Sugimoto, Reiko; Yamagishi, Kazuo

    2013-01-01

    Gamma-glutamylcysteine (?-GC), the precursor of glutathione (GSH), may have significant health benefits as a dietary supplement, but there are few cost-effective methods available for its large-scale production. We developed an efficient method for producing ?-GC in a mutant yeast strain using a three-step breeding procedure and a unique cultivation process. In the first breeding step, we prepared a glutathione synthetase (GSH2)-deficient yeast mutant. In the second step, selenate (SeO(4)(2-)) sensitivity was introduced by crossing the GSH2-deficient mutant with a strain harboring the met30 mutation. In the final step, pantothenic acid auxotrophy was introduced by ethyl methanesulfonate mutagenesis. The isolated strain displayed significantly enhanced cellular ?-GC when cultivated in synthetic medium without pantothenic acid, reaching a maximum level of 4.39% of dry cell weight. Using this strain, we were able to prepare a yeast extract containing approximately 13% ?-GC (w/w), which is markedly higher than the reported value (0.3%) of commercially available yeast extracts. The present method may facilitate large-scale ?-GC production for investigating the nutritive value and other benefits of dietary ?-GC. PMID:22986308

  6. Mining metabolites: extracting the yeast metabolome from the literature

    Microsoft Academic Search

    Chikashi NobataPaul; Paul D. Dobson; Syed A. Iqbal; Pedro Mendes; Jun’ichi Tsujii; Douglas B. Kell; Sophia Ananiadou

    2011-01-01

    Text mining methods have added considerably to our capacity to extract biological knowledge from the literature. Recently\\u000a the field of systems biology has begun to model and simulate metabolic networks, requiring knowledge of the set of molecules\\u000a involved. While genomics and proteomics technologies are able to supply the macromolecular parts list, the metabolites are\\u000a less easily assembled. Most metabolites are

  7. Sucrose and Related Oligosaccharides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This is a textbook chapter on sucrose and related oligosaccharides. Contents include the industrial production of sugar (sucrose) from sugarcane and sugarbeet, physical and chemical properties of sucrose including conformation studies, various analyses of sucrose, current commercial and anticipated ...

  8. Acceleration of yoghurt fermentation time by yeast extract and partial characterisation of the active components.

    PubMed

    Smith, Esti-Andrine; Myburgh, Jacobus; Osthoff, Gernot; de Wit, Maryna

    2014-11-01

    Water soluble autolysate of yeast, usually utilised for microbial growth support, was used as additive in yoghurt fermentation. The yeast extract (YE) resulted in a decrease of fermentation time by 21% to reach a pH of 4·6. However, the YE resulted in unacceptable flavour and taste. By size exclusion chromatography, a fraction of the YE was obtained that could account for the observed 21% decrease in fermentation time. The fraction contained molecules of low molecular weight, consisting of minerals, free amino acids and peptides. The acceleration of the yoghurt fermentation was ascribed to the short peptides in the fraction. It is proposed that the application of this extract in industrial yoghurt manufacture would result in savings for both the industry and the consumer. PMID:25353311

  9. Methyl jasmonate and yeast extract stimulate mitragynine production in Mitragyna speciosa (Roxb.) Korth. shoot culture.

    PubMed

    Wungsintaweekul, Juraithip; Choo-Malee, Jutarat; Charoonratana, Tossaton; Keawpradub, Niwat

    2012-10-01

    Mitragynine is a pharmacologically-active terpenoid indole alkaloid found in Mitragyna speciosa leaves. Treatment with methyl jasmonate (10 ?M) for 24 h and yeast extract (0.1 mg/ml) for 12 h were the optimum conditions of elicitation of mitragynine accumulation in a M. speciosa shoot culture. The former elicitor gave 0.11 mg mitragynine/g dry wt. Tryptophan decarboxylase and strictosidine synthase mRNA levels were enhanced in accordance with mitragynine accumulation. PMID:22714271

  10. Induction of rosmarinic acid biosynthesis in Lithospermum erythrorhizon cell suspension cultures by yeast extract

    Microsoft Academic Search

    Hajime Mizukami; Terumi Ogawa; Hiromu Ohashi; Brian E. Ellis

    1992-01-01

    A transient increase in rosmarinic acid (RA) content in cultured cells of Lithospermum erythrorhizon was observed after addition of yeast extract (YE) to the suspension cultures, reaching a maximum at 24 hr. The highest increase of the RA content (2.5-fold) was obtained when 6-day-old cells in the exponential growth phase were treated with YE. Preceding the induced RA accumulation, phenylalanine

  11. Extractable activities and protein content of sucrose-phosphate synthase, sucrose synthase and neutral invertase in trunk tissues of Robinia pseudoacacia L. are related to cambial wood production and heartwood formation

    Microsoft Academic Search

    Siegfried Hauch; Elisabeth Magel

    1998-01-01

    .   The presence of sucrose synthesizing and degrading enzymes and the correlation of their enzyme activity with cambial growth\\u000a and heartwood formation are demonstrated in trunks of Robinia pseudoacacia L., black locust. Sucrose is formed by sucrose-phosphate synthase (SPS; EC 2.4.1.14), predominantly in the storage part of\\u000a the sapwood. In the cambial differentiation zone and the sapwood-heartwood transition zone, both

  12. Chlorhexidine: beta-cyclodextrin inhibits yeast growth by extraction of ergosterol

    PubMed Central

    Teixeira, K. I. R.; Araújo, P. V.; Sinisterra, R. D.; Cortés, M. E.

    2012-01-01

    Chlorhexidine (Cx) augmented with beta-cyclodextrin (?-cd) inclusion compounds, termed Cx:?-cd complexes, have been developed for use as antiseptic agents. The aim of this study was to examine the interactions of Cx:?-cd complexes, prepared at different molecular ratios, with sterol and yeast membranes. The Minimal Inhibitory Concentration (MIC) against the yeast Candida albicans (C.a.) was determined for each complex; the MICs were found to range from 0.5 to 2 ?g/mL. To confirm the MIC data, quantitative analysis of viable cells was performed using trypan blue staining. Mechanistic characterization of the interactions that the Cx:?-cd complexes have with the yeast membrane and assessment of membrane morphology following exposure to Cx:?-cd complexes were performed using Sterol Quantification Method analysis (SQM) and scanning electron microscopy (SEM). SQM revealed that sterol extraction increased with increasing ?-cd concentrations (1.71 ×103; 1.4 ×103; 3.45 ×103, and 3.74 ×103 CFU for 1:1, 1:2, 1:3, and 1:4, respectively), likely as a consequence of membrane ergosterol solubilization. SEM images demonstrated that cell membrane damage is a visible and significant mechanism that contributes to the antimicrobial effects of Cx:?-cd complexes. Cell disorganization increased significantly as the proportion of ?-cyclodextrin present in the complex increased. Morphology of cells exposed to complexes with 1:3 and 1:4 molar ratios of Cx:?-cd were observed to have large aggregates mixed with yeast remains, representing more membrane disruption than that observed in cells treated with Cx alone. In conclusion, nanoaggregates of Cx:?-cd complexes block yeast growth via ergosterol extraction, permeabilizing the membrane by creating cluster-like structures within the cell membrane, possibly due to high amounts of hydrogen bonding. PMID:24031894

  13. Trophic effect of a methanol yeast extract on 3T3 fibroblast cells.

    PubMed

    Gallo, Dominique; Dillemans, Monique; Allardin, David; Priem, Fabian; Van Nedervelde, Laurence

    2014-01-01

    With regard to the increase of human life expectancy, interest for topical treatments aimed to counteract skin aging is still growing. Hence, research for bioactive compounds able to stimulate skin fibroblast activity is an attractive topic. Having previously described the effects of a new methanol yeast extract on growth and metabolic activity of Saccharomyces cerevisiae, we studied its effects on 3T3 fibroblasts to evaluate its potential antiaging property. This investigation demonstrates that this extract increases proliferation as well as migration of 3T3 cells and decreases their entrance in senescence and apoptosis phases. Altogether, these results open new perspectives for the formulation of innovative antiaging topical treatments. PMID:25898765

  14. Extraction of brewer's yeasts using different methods of cell disruption for practical biodiesel production.

    PubMed

    ?ezanka, Tomáš; Matoulková, Dagmar; Kolouchová, Irena; Masák, Jan; Viden, Ivan; Sigler, Karel

    2015-05-01

    The methods of preparation of fatty acids from brewer's yeast and its use in production of biofuels and in different branches of industry are described. Isolation of fatty acids from cell lipids includes cell disintegration (e.g., with liquid nitrogen, KOH, NaOH, petroleum ether, nitrogenous basic compounds, etc.) and subsequent processing of extracted lipids, including analysis of fatty acid and computing of biodiesel properties such as viscosity, density, cloud point, and cetane number. Methyl esters obtained from brewer's waste yeast are well suited for the production of biodiesel. All 49 samples (7 breweries and 7 methods) meet the requirements for biodiesel quality in both the composition of fatty acids and the properties of the biofuel required by the US and EU standards. PMID:25394535

  15. A Yeast Metabolite Extraction Protocol Optimised for Time-Series Analyses

    PubMed Central

    Sasidharan, Kalesh; Soga, Tomoyoshi; Tomita, Masaru; Murray, Douglas B.

    2012-01-01

    There is an increasing call for the absolute quantification of time-resolved metabolite data. However, a number of technical issues exist, such as metabolites being modified/degraded either chemically or enzymatically during the extraction process. Additionally, capillary electrophoresis mass spectrometry (CE-MS) is incompatible with high salt concentrations often used in extraction protocols. In microbial systems, metabolite yield is influenced by the extraction protocol used and the cell disruption rate. Here we present a method that rapidly quenches metabolism using dry-ice ethanol bath and methanol N-ethylmaleimide solution (thus stabilising thiols), disrupts cells efficiently using bead-beating and avoids artefacts created by live-cell pelleting. Rapid sample processing minimised metabolite leaching. Cell weight, number and size distribution was used to calculate metabolites to an attomol/cell level. We apply this method to samples obtained from the respiratory oscillation that occurs when yeast are grown continuously. PMID:22952947

  16. In vivo antiprostate tumor potential of Vernonia guineensis Benth. (Asteraceae) tuber extract (VGDE) and the cytotoxicity of its major compound pentaisovaleryl sucrose

    PubMed Central

    Toyang, Ngeh J.; Ateh, Eugene N.; Davis, Harry; Tane, Pierre; Sondengam, Luc B.; Bryant, Joseph; Verpoorte, Rob

    2015-01-01

    Ethnopharmacological relevance Vernonia guineensis Benth. (Asteraceae) root decoction is used in folk medicine in Cameroon to treat some ailments including prostate cancer. The aim of this study was to validate the claimed antiprostate cancer activity of Vernonia guineensis Benth. in vivo and to investigate the cytotoxicity of a pentaisovaleryl sucrose isolated from Vernonia guineensis on some cancer cell lines. Materials and methods A crude dichloromethane extract of Vernonia guineensis (VGDE) was used for this study. For in vivo antiprostate cancer efficacy, nude mice (n = 16) were injected subcutaneously with prostate cancer PC-3 cells. Upon the formation of the xenograft tumors, the mice were divided into two equal groups with approximately the same mean tumor volume per group. One group was treated with VGDE orally (500 mg/kg) and the other with a vehicle control for 30 days. Body weight and tumor volumes were measured 2 × a week and on the 33rd day, the mice were euthanized and tumors harvested and weighed. For the cytotoxicity study, the WST-1 assay was used to determine the activity of pentaisovaleryl sucrose previously isolated from VGDE. The cancer cell lines used in the cytotoxicity study included breast, colon, leukemia, lung, melanoma, ovarian and prostate. Results Prostate cancer (PC-3) xenograft tumors treated with VGDE showed a significant decrease in tumor size (P = 0.0295) compared to control. Pentaisovaleryl sucrose also demonstrated cytotoxicity against various cancer cell lines with IC50 values as follows: MDA-MD-231—6.66 µM; MCF-7—7.50 µM; HCT116—14.12 µM; A549—5.76 µM; HL60—6.43 µM; A375—8.64 µM; OVCAR3—9.53 µM; Capan1—7.13 µM; Mia-Paca 6.47 µM. Conclusion VGDE does possess in vivo activity against prostate tumor and has potential for development into a natural product for the treatment of prostate cancer. This study thus provides preliminary validation for the folk use of Vernonia guineensis against prostate conditions. Further in vivo studies are however required to confirm these results and to understand the mechanism of action of VGDE and the in vivo efficacy of pentaisovaleryl sucrose. PMID:24095832

  17. Fractionation and characterization of a yeast mRNA splicing extract.

    PubMed Central

    Cheng, S C; Abelson, J

    1986-01-01

    We have fractionated a yeast whole cell extract that can accurately splice synthetic actin and CYH2 pre-mRNAs. Three fractions, designated I, II, and III, have been separated by use of ammonium sulfate fractionation and chromatography on heparin agarose. Each fraction alone has no splicing activity. Fractions I and II allow the first step of the splicing reaction to proceed, giving rise to the splicing intermediates, free exon 1, and intron-exon 2. Addition of fraction III completes the reaction. Micrococcal nuclease treatment of the whole cell extract or of either fraction I or II abolished splicing activity, indicating that fractions I and II have RNA moieties that are required in the splicing reaction. The nature of the RNAs was examined using antibodies directed against the trimethylated cap structure unique to small nuclear RNAs. Preincubation of the whole cell extract with protein A-Sepharose coupled to trimethylated cap antibody abolished splicing activity. This indicates that at least one essential RNA component contains a trimethyl cap. Thus, in yeast as in mammalian systems, small nuclear RNAs are involved in mRNA splicing. Images PMID:3517868

  18. Effect of scenedesmus acuminatus green algae extracts on the development of Candida lipolytic yeast in gas condensate-containing media

    NASA Technical Reports Server (NTRS)

    Bilmes, B. I.; Kasymova, G. A.; Runov, V. I.; Karavayeva, N. N.

    1980-01-01

    Data are given of a comparative study of the growth and development as well as the characteristics of the biomass of the C. Lipolytica yeast according to the content of raw protein, protein, lipids, vitamins in the B group, and residual hydrocarbons during growth in media with de-aromatized gas-condensate FNZ as the carbon source with aqueous and alcohol extracts of S. acuminatus as the biostimulants. It is shown that the decoction and aqueous extract of green algae has the most intensive stimulating effect on the yeast growth. When a decoction of algae is added to the medium, the content of residual hydrocarbons in the biomass of C. lipolytica yeast is reduced by 4%; the quantity of protein, lipids, thamine and inositol with replacement of the yeast autolysate by the decoction of algae is altered little.

  19. In vitro formation of the anthranoid scaffold by cell-free extracts from yeast-extract-treated Cassia bicapsularis cell cultures.

    PubMed

    Abdel-Rahman, Iman A M; Beuerle, Till; Ernst, Ludger; Abdel-Baky, Afaf M; Desoky, Ezz El-Din K; Ahmed, Amany S; Beerhues, Ludger

    2013-04-01

    The anthranoid skeleton is believed to be formed by octaketide synthase (OKS), a member of the type III polyketide synthase (PKS) superfamily. Recombinant OKSs catalyze stepwise condensation of eight acetyl units to form a linear octaketide intermediate which, however, is incorrectly folded and cyclized to give the shunt products SEK4 and SEK4b. Here we report in vitro formation of the anthranoid scaffold by cell-free extracts from yeast-extract-treated Cassia bicapsularis cell cultures. Unlike field- and in vitro-grown shoots which accumulate anthraquinones, cell cultures mainly contained tetrahydroanthracenes, formation of which was increased 2.5-fold by the addition of yeast extract. The elicitor-stimulated accumulation of tetrahydroanthracenes was preceded by an approx. 35-fold increase in OKS activity. Incubation of cell-free extracts from yeast-extract-treated cell cultures with acetyl-CoA and [2-(14)C]malonyl-CoA led to formation of torosachrysone (tetrahydroanthracene) and emodin anthrone, beside two yet unidentified products. No product formation occurred in the absence of acetyl-CoA as starter substrate. To confirm the identities of the enzymatic products, cell-free extracts were incubated with acetyl-CoA and [U-(13)C(3)]malonyl-CoA and (13)C incorporation was analyzed by ESI-MS/MS. Detection of anthranoid biosynthesis in cell-free extracts indicates in vitro cooperation of OKS with a yet unidentified factor or enzyme for octaketide cyclization. PMID:23395285

  20. Photocatalytic activity of biogenic silver nanoparticles synthesized using yeast (Saccharomyces cerevisiae) extract

    NASA Astrophysics Data System (ADS)

    Roy, Kaushik; Sarkar, C. K.; Ghosh, C. K.

    2014-12-01

    Synthesis of metallic and semiconductor nanoparticles through physical and chemical route is quiet common but biological synthesis procedures are gaining momentum due to their simplicity, cost-effectivity and eco-friendliness. Here, we report green synthesis of silver nanoparticles from aqueous solution of silver salts using yeast (Saccharomyces cerevisiae) extract. The nanoparticles formation was gradually investigated by UV-Vis spectrometer. X-ray diffraction analysis was done to identify different phases of biosynthesized Ag nanoparticles. Transmission electron microscopy was performed to study the particle size and morphology of silver nanoparticles. Fourier transform infrared spectroscopy of the nanoparticles was performed to study the role of biomolecules capped on the surface of Ag nanoparticles during interaction. Photocatalytic activity of these biosynthesized nanoparticles was studied using an organic dye, methylene blue under solar irradiation and these nanoparticles showed efficacy in degrading the dye within a few hours of exposure.

  1. Accelerated solvent extraction of monacolin K from red yeast rice and purification by high-speed counter-current chromatography.

    PubMed

    Liu, Yuqin; Guo, Xingfeng; Duan, Wenjuan; Wang, Xiao; Du, Jinhua

    2010-10-15

    Monacolin K from red yeast rice was extracted by accelerated solvent extraction (ASE). The effects of various extraction parameters including extraction temperature, static extraction time and cycle index on yield were investigated using a DIONEX ASE 300 system to select the optimal conditions by an orthogonal test design L(9) (3)(3). The optimum extraction conditions were determined as follows: extraction temperature 120°C, static extraction time 7min, and cycle index 3. Under the optimal conditions, the yield of ASE extract and monacolin K was 5.35% and 9.26mg/g of dry red yeast rice, respectively. A separation and purification method of monacolin K was then established using high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (8:2:5:5, v/v/v/v). From 300mg of crude extract, 51.2mg of monacolin K was obtained with the purity of 98.7%. The chemical structure of isolated compound was identified by UV, ESI-MS and (1)H NMR. PMID:20869335

  2. Red yeast rice extracts suppress adipogenesis by down-regulating adipogenic transcription factors and gene expression in 3T3-L1 cells

    Microsoft Academic Search

    Taeil Jeon; Seong Gu Hwang; Shizuka Hirai; Tohru Matsui; Hideo Yano; Teruo Kawada; Beoung Ou Lim; Dong Ki Park

    2004-01-01

    The effects of red yeast rice extracts (RE) on adipocyte differentiation of 3T3-L1 cells were studied. RE were extracted from embryonic rice fermented with red yeast (Monascus ruber). These extracts significantly decreased glycerol-3-phosphate dehydrogenase (GPDH) activity and lipid accumulation, a marker of adipogenesis, in a dose-dependent manner. Moreover, mRNA expression levels of both CCAAT\\/enhancer-binding protein (C\\/EBP) ? and peroxisome proliferator-activated

  3. In Vivo Hypocholesterolemic Effect of MARDI Fermented Red Yeast Rice Water Extract in High Cholesterol Diet Fed Mice

    PubMed Central

    Beh, Boon Kee; Kong, Joan; Ho, Wan Yong; Mohd Yusof, Hamidah; Hussin, Aminuddin bin; Jaganath, Indu Bala; Alitheen, Noorjahan Banu; Jamaluddin, Anisah

    2014-01-01

    Fermented red yeast rice has been traditionally consumed as medication in Asian cuisine. This study aimed to determine the in vivo hypocholesterolemic and antioxidant effects of fermented red yeast rice water extract produced using Malaysian Agricultural Research and Development Institute (MARDI) Monascus purpureus strains in mice fed with high cholesterol diet. Absence of monacolin-k, lower level of ?-aminobutyric acid (GABA), higher content of total amino acids, and antioxidant activities were detected in MARDI fermented red yeast rice water extract (MFRYR). In vivo MFRYR treatment on hypercholesterolemic mice recorded similar lipid lowering effect as commercial red yeast rice extract (CRYR) as it helps to reduce the elevated serum liver enzyme and increased the antioxidant levels in liver. This effect was also associated with the upregulation of apolipoproteins-E and inhibition of Von Willebrand factor expression. In summary, MFRYR enriched in antioxidant and amino acid without monacolin-k showed similar hypocholesterolemic effect as CRYR that was rich in monacolin-k and GABA. PMID:25031606

  4. In Vivo Hypocholesterolemic Effect of MARDI Fermented Red Yeast Rice Water Extract in High Cholesterol Diet Fed Mice.

    PubMed

    Yeap, Swee Keong; Beh, Boon Kee; Kong, Joan; Ho, Wan Yong; Mohd Yusof, Hamidah; Mohamad, Nurul Elyani; Hussin, Aminuddin Bin; Jaganath, Indu Bala; Alitheen, Noorjahan Banu; Jamaluddin, Anisah; Long, Kamariah

    2014-01-01

    Fermented red yeast rice has been traditionally consumed as medication in Asian cuisine. This study aimed to determine the in vivo hypocholesterolemic and antioxidant effects of fermented red yeast rice water extract produced using Malaysian Agricultural Research and Development Institute (MARDI) Monascus purpureus strains in mice fed with high cholesterol diet. Absence of monacolin-k, lower level of ?-aminobutyric acid (GABA), higher content of total amino acids, and antioxidant activities were detected in MARDI fermented red yeast rice water extract (MFRYR). In vivo MFRYR treatment on hypercholesterolemic mice recorded similar lipid lowering effect as commercial red yeast rice extract (CRYR) as it helps to reduce the elevated serum liver enzyme and increased the antioxidant levels in liver. This effect was also associated with the upregulation of apolipoproteins-E and inhibition of Von Willebrand factor expression. In summary, MFRYR enriched in antioxidant and amino acid without monacolin-k showed similar hypocholesterolemic effect as CRYR that was rich in monacolin-k and GABA. PMID:25031606

  5. Copper and the ACE1 Regulatory Protein Reversibly Induce Yeast Metallothionein Gene Transcription in a Mouse Extract

    NASA Astrophysics Data System (ADS)

    Cizewski Culotta, Valeria; Hsu, Tsao; Hu, Stella; Furst, Peter; Hamer, Dean

    1989-11-01

    We describe a cell-free system in which the transcription of the yeast metallothionein gene is inducible by the addition of metal ions plus a specific regulatory protein. Efficient transcription requires the complete yeast ACE1 metalloregulatory protein, including both its DNA-binding and transactivation domains; a mouse nuclear extract providing RNA polymerase and general transcription factors; a template containing the ACE1 binding site; and Cu(I). Because the binding of ACE1 to DNA is dependent on Cu, it is possible to inhibit transcription by the use of Cu-complexing agents such as CN-. We have used this specific inhibition to show that the ACE1 regulatory protein is required for the maintenance as well as the formation of a functional preinitiation complex. The ability to reversibly induce yeast metallothionein gene transcription in vitro provides a powerful system for determining the molecular mechanism of a simple eukaryotic regulatory circuit.

  6. Transgenic cotton over-producing spinach sucrose phosphate synthase showed enhanced leaf sucrose synthesis and improved

    E-print Network

    Strauss, Richard E.

    , and development of enhanced extractable Vmax SPS activ- ity in leaf and fiber. Lines with the highest Vmax SPSTransgenic cotton over-producing spinach sucrose phosphate synthase showed enhanced leaf sucrose activity in leaf and fiber had higher fiber micro- naire and maturity ratio associated with greater thick

  7. Sucrose Phosphate Is Not Transported into Vacuoles or Tonoplast Vesicles from Red Beet (Beta vulgaris) Hypocotyl.

    PubMed

    Echeverria, E; Salvucci, M E

    1991-08-01

    Tonoplast vesicles and vacuoles isolated from red beet (Beta vulgaris L.) hypocotyl accumulated externally supplied [(14)C]sucrose but not [(14)C]sucrose phosphate despite the occurrence of sucrose phosphate phosphohydrolytic activity in the vacuole. The activities of sucrose synthase and sucrose phosphate synthase in whole cell extracts were 960 and 30 nanomoles per milligram protein per minute, respectively; whereas, no sucrose synthesizing activity was measured in tonoplast preparations. The results obtained in this investigation are incompatible with the involvement of sucrose phosphate synthase in the process of sucrose synthesis and accumulation in the storage cells of red beet. PMID:16668291

  8. Glucosyltransferase production by Klebsiella sp. K18 and conversion of sucrose to palatinose using immobilized cells

    PubMed Central

    Orsi, Daniela C.; Kawaguti, Haroldo Y.; Sato, Hélia H.

    2009-01-01

    The strain Klebsiella sp. K18 produces the enzyme glucosyltransferase and catalyses the conversion of sucrose to palatinose, an alternative sugar that presents low cariogenicity. Response Surface Methodology was successfully employed to determine the optimal concentration of culture medium components. Maximum glucosyltransferase production (21.78 U mL-1) was achieved using the optimized medium composed by sugar cane molasses (80 g L-1), bacteriological peptone (7 g L-1) and yeast extract (20 g L-1), after 8 hours of fermentation at 28°C. The conversion of sucrose to palatinose was studied utilizing immobilized cells in calcium alginate. The effects of the alginate concentration (2-4%), cell mass concentration (20-40%) and substrate concentration (25-45%) were evaluated and the yield of palatinose was approximately 62.5%. PMID:24031319

  9. Fermentation of five sucrose isomers by human dental plaque bacteria.

    PubMed

    Matsuyama, J; Sato, T; Hoshino, E; Noda, T; Takahashi, N

    2003-01-01

    Sucrose has five structural isomers: palatinose, trehalulose, turanose, maltulose and leucrose. Although these isomers have been reported to be noncariogenic disaccharides, which cannot be utilized by mutans streptococci, there is no information about their fermentability by other bacteria in dental plaque. The purpose of the present study was to examine whether these isomers were fermented by predominant bacteria in human dental plaque. Clinical bacterial isolates obtained from dental plaque from 3 children aged 22 months to 50 months (146 strains) were inoculated into 3 ml of peptone-yeast extract (PY medium) containing glucose for 1 day, then an aliquot of 20 microl of culture medium was inoculated into 1 ml of PY medium containing 1% (w/v) of the respective test carbohydrates. After incubation for 1 day, the pH values and the optical density at 660 nm of the cultures were measured. Fermentation ability was measured by pH or=0.5. Of the clinical isolates, 33% fermented palatinose, and 69% of these were Actinomyces species. All of the palatinose-fermenting bacterial strains fermented trehalulose, 25% fermented turanose, 70% fermented maltulose and 23% fermented leucrose. We therefore conclude that, in human dental plaque, there are significant numbers of bacteria that are able to ferment sucrose isomers. PMID:14571118

  10. Measurement of the relative sweetness of stevia extract, aspartame and cyclamate\\/saccharin blend as compared to sucrose at different concentrations

    Microsoft Academic Search

    H. M. A. B. Cardello; M. A. P. A. Da Silva; M. H. Damasio

    1999-01-01

    Special diets are used to mitigate many human diseases. When these diets require changes in carbohydrate content, then sweetness becomes an important characteristic. The range of low-calorie sweeteners available to the food industry is expanding. It is essential to have an exact knowledge of the relative sweetness of various sweeteners in relation to different sucrose concentrations. The objective of this

  11. Sucrose signaling in plants

    PubMed Central

    Tognetti, Jorge A.; Pontis, Horacio G.; Martínez-Noël, Giselle M.A.

    2013-01-01

    The role of sucrose as a signaling molecule in plants was originally proposed several decades ago. However, recognition of sucrose as a true signal has been largely debated and only recently this role has been fully accepted. The best-studied cases of sucrose signaling involve metabolic processes, such as the induction of fructan or anthocyanin synthesis, but a large volume of scattered information suggests that sucrose signals may control a vast array of developmental processes along the whole life cycle of the plant. Also, wide gaps exist in our current understanding of the intracellular steps that mediate sucrose action. Sucrose concentration in plant tissues tends to be directly related to light intensity, and inversely related to temperature, and accordingly, exogenous sucrose supply often mimics the effect of high light and cold. However, many exceptions to this rule seem to occur due to interactions with other signaling pathways. In conclusion, the sucrose role as a signal molecule in plants is starting to be unveiled and much research is still needed to have a complete map of its significance in plant function. PMID:23333971

  12. Enrichment of yeast thioredoxin by green tea extract through activation of Yap1 transcription factor in Saccharomyces cerevisiae.

    PubMed

    Takatsume, Yoshifumi; Maeta, Kazuhiro; Izawa, Shingo; Inoue, Yoshiharu

    2005-01-26

    Thioredoxin (TRX) is an important antioxidant present in all types of organisms. Besides its role as an antioxidant, TRX protects the gastric mucosa due to its antiinflammatory effect. In addition, TRX decreases allergenicity; therefore, the oral administration of TRX is of considerable interest with respect to its clinical use as well as the development of functional foods containing TRX. We have attempted to enrich the cellular TRX content in Saccharomyces cerevisiae, and found that green tea extract (Sunphenon), which is rich in catechins (polyphenols), activates the Yap1 transcription factor, leading to the induction of TRX2, a target of Yap1. Production of yeast TRX was monitored by both a TRX2-lacZ reporter expression assay and Western blotting using an anti-yeast TRX antibody. Maximal production of TRX was achieved in a medium containing 0.1% green tea extract at pH 7.6. We discuss the underlying mechanism by which green tea extract activates Yap1. PMID:15656669

  13. Sucrose Phosphate Is Not Transported into Vacuoles or Tonoplast Vesicles from Red Beet (Beta vulgaris) Hypocotyl 1

    PubMed Central

    Echeverria, Ed; Salvucci, Michael E.

    1991-01-01

    Tonoplast vesicles and vacuoles isolated from red beet (Beta vulgaris L.) hypocotyl accumulated externally supplied [14C]sucrose but not [14C]sucrose phosphate despite the occurrence of sucrose phosphate phosphohydrolytic activity in the vacuole. The activities of sucrose synthase and sucrose phosphate synthase in whole cell extracts were 960 and 30 nanomoles per milligram protein per minute, respectively; whereas, no sucrose synthesizing activity was measured in tonoplast preparations. The results obtained in this investigation are incompatible with the involvement of sucrose phosphate synthase in the process of sucrose synthesis and accumulation in the storage cells of red beet. PMID:16668291

  14. Influence of hen age on the response of turkey poults to cold stress, Escherichia coli challenge, and treatment with a yeast extract antibiotic alternative.

    PubMed

    Huff, G R; Huff, W E; Rath, N C; Solis de Los Santos, F; Farnell, M B; Donoghue, A M

    2007-04-01

    Two battery experiments were conducted to evaluate a commercial yeast extract feed supplement, Alphamune, in a cold stress-Escherichia coli challenge of 1-wk-old turkeys. Experiment 1 used 1-d-old male poults that were the progeny of 33-wk-old hens in their second week of lay. Experiment 2 used male poults of the same genetic line from 40-wk-old hens in their eighth week of lay. Poults were fed a standard unmedicated turkey starter diet or the same diet with either a low level (504 g/t) or a high level (1,008 g/t) of yeast extract. Challenged birds were exposed to intermittent cold stress during wk 1 to 3 and to a respiratory E. coli challenge at 1 wk of age. In both experiments, BW at wk 1 was increased by feeding yeast extract. In experiment 1, challenged, control-fed birds had decreased BW at wk 3 and feed conversion was protected by both levels of yeast extract supplementation. In experiment 2, challenge had no effect on control-fed birds; however, yeast extract decreased the BW of challenged birds. In experiment 1, total leukocyte numbers were decreased by challenge of control-fed birds only, and there was no effect of challenge on the heterophil/lymphocyte ratio. In experiment 2, total leukocyte numbers were decreased and the heterophil/lymphocyte ratio was increased in challenged, control-fed birds. Percentage mortality was not affected by challenge in experiment 1; however, in experiment 2, mortality was increased by challenge of control-fed birds and those fed the lower level of yeast extract. These results suggest that hen age should be considered when designing studies to evaluate antibiotic alternatives and in making decisions for incorporating such alternatives into production. PMID:17369533

  15. [Studies on the effects of carbon:nitrogen ratio, inoculum type and yeast extract addition on jasmonic acid production by Botryodiplodia theobromae Pat. strain RC1].

    PubMed

    Eng Sánchez, Felipe; Gutiérrez-Rojas, Mariano; Favela-Torres, Ernesto

    2008-09-30

    Jasmonic acid is a native plant growth regulator produced by algae, microorganisms and higher plants. This regulator is involved in the activation of defence mechanisms against pathogens and wounding in plants. Studies concerning the effects of carbon: nitrogen ratio (C/Nr: 17, 35 and 70), type of inoculum (spores or mycelium) and the yeast extract addition in the media on jasmonic acid production by Botryodiplodia theobromae were evaluated. Jasmonic acid production was stimulated at the carbon: nitrogen ratio of 17. Jasmonic acid productivity was higher in the media inoculated with mycelium and in the media with yeast extract 1.7 and 1.3 times, respectively. PMID:18785793

  16. 21 CFR 184.1854 - Sucrose.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...?-D-fructofuranosyl-?-D-glucopyranoside. Sucrose is obtained by crystallization from sugar cane or sugar beet juice that has been extracted by pressing or diffusion, then clarified and evaporated. (b) The ingredient must be of a purity suitable for its intended use. (c)...

  17. 21 CFR 184.1854 - Sucrose.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...?-D-fructofuranosyl-?-D-glucopyranoside. Sucrose is obtained by crystallization from sugar cane or sugar beet juice that has been extracted by pressing or diffusion, then clarified and evaporated. (b) The ingredient must be of a purity suitable for its intended use. (c)...

  18. Yeast ecology of Kombucha fermentation

    Microsoft Academic Search

    Ai Leng Teoh; Gillian Heard; Julian Cox

    2004-01-01

    Kombucha is a traditional fermentation of sweetened tea, involving a symbiosis of yeast species and acetic acid bacteria. Despite reports of different yeast species being associated with the fermentation, little is known of the quantitative ecology of yeasts in Kombucha. Using oxytetracycline-supplemented malt extract agar, yeasts were isolated from four commercially available Kombucha products and identified using conventional biochemical and

  19. Growth and lactic acid production by Lactobacillus casei ssp. rhamnosus in batch and membrane bioreactor: influence of yeast extract and Tryptone enrichment

    Microsoft Academic Search

    A. Olmos-Dichara; F. Ampe; J.-L. Uribelarrea; A. Pareilleux; G. Goma

    1997-01-01

    Enrichment of the medium with yeast extract (20 g.l ) and Tryptone (40 g.l ) increased the growth of Lactobacillus casei ssp. rhamnosusand its production of lactic acid in both batch and cell-recycle cultures without affecting glucose consumption and the lactic acid production rate.

  20. Phloem Loading by the PmSUC2 Sucrose Carrier from Plantago major Occurs into Companion Cells.

    PubMed Central

    Stadler, R.; Brandner, J.; Schulz, A.; Gahrtz, M.; Sauer, N.

    1995-01-01

    High levels of mRNA for the sucrose-H+ symporter PmSUC2 have been found in the vascular bundles of petioles from Plantago major. The possible role of PmSUC2 in phloem loading was studied with antiserum raised against the recombinant PmSUC2 protein. This antiserum labeled a single 35-kD protein band in detergent extracts of P. major vascular bundles. It showed no cross-reaction with the P. major sucrose carrier PmSUC1, which was tested with detergent extracts from plasma membranes of transgenic yeast strains containing either the P. major sucrose transporter PmSUC1 or PmSUC2. The antiserum was used to determine the site of PmSUC2 expression in leaves, petioles, and roots of P. major. In cross-sections and longitudinal sections, the PmSUC2 protein was found in only one single cell type. These cells were identified as companion cells because they are nucleated, contain a dense cytoplasm, and are always adjacent to a sieve element. The labeled cells had the same longitudinal extension as did their sister sieve elements and always ended next to the sieve plates, which were characterized by specific staining. PmSUC2 mRNA and PmSUC2 protein were also detected in P. major roots. The function of PmSUC2 in the different organs and its role in phloem loading are discussed. PMID:12242355

  1. Extraction of ethanol with higher alcohol solvents and their toxicity to yeast

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In a solvent extraction screening study, several beta-branched alcohols in the 16 ­ 20 carbons range show improved extractive performance to recover ethanol from aqueous solutions compared to commonly studied solvents such as oleyl alcohol and 1-dodecanol. These beta-branched alcohols were selected ...

  2. Sucrose Synthase: Expanding Protein Function

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sucrose synthase (SUS: EC 2.4.1.13), a key enzyme in plant sucrose catabolism, is uniquely able to mobilize sucrose into multiple pathways involved in metabolic, structural, and storage functions. Our research indicates that the biological function of SUS may extend beyond its catalytic activity. Th...

  3. Carbohydrates: Sucrose p. Carbon Metabolism, Carbohydrates & Sugars

    E-print Network

    Constabel, Peter

    Carbohydrates: Sucrose p. Carbon Metabolism, Carbohydrates & Sugars 1. Introduction and overview on carbohydrate and sugars (handout) Carbohydrate [CHO] = polyhydroxyketones and polyhydroxyaldehydes - two types reducing power - integrated with sucrose and starch synthesis #12;Carbohydrates: Sucrose p. 2 2 Sucrose

  4. A new ?-glucosidase producing yeast for lower-cost cellulosic ethanol production from xylose-extracted corncob residues by simultaneous saccharification and fermentation.

    PubMed

    Liu, Z Lewis; Weber, Scott A; Cotta, Michael A; Li, Shi-Zhong

    2012-01-01

    This study reports a new yeast strain of Clavispora NRRL Y-50464 that is able to utilize cellobiose as sole source of carbon and produce sufficient native ?-glucosidase enzyme activity for cellulosic ethanol production using SSF. In addition, this yeast is tolerant to the major inhibitors derived from lignocellulosic biomass pre-treatment such as 2-furaldehyde (furfural) and 5-(hydroxymethyl)-2-furaldehyde (HMF), and converted furfural into furan methanol in less than 12h and HMF into furan-2,5-dimethanol within 24h in the presence of 15 mM each of furfural and HMF. Using xylose-extracted corncob residue as cellulosic feedstock, an ethanol production of 23 g/l was obtained using 25% solids loading at 37 °C by SSF without addition of exogenous ?-glucosidase. Development of this yeast aids renewable biofuels development efforts for economic consolidated SSF bio-processing. PMID:22133603

  5. Oligosaccharides Derived from Sucrose

    NASA Astrophysics Data System (ADS)

    Monsan, Pierre F.; Ouarné, Francois

    Sucrose is a non-reducing disaccharide, consisting of an ?-D-glucopyranosyl residue and a ?-D-fructofuranosyl residue linked covalently by their respective anomeric carbons (?-D-glucopyranosyl-1,2-?-D-fructofuranoside). It is not just a simple disaccharide, among others: in fact, the energy of its glycosidic bond is higher than that of a usual glycosidic bond. It is equal to 27.6 kJ/mol, which is similar to the energy of a nucleotide-sugar bond as in UDP-glucose or ADP-glucose. This means that sucrose is a protected and activated form of D-glucose (as well as of D-fructose), which plays a key role in the metabolism of plants, for a wide variety of synthesis reactions.

  6. Extraction of ethanol with higher carboxylic acid solvents and their toxicity to yeast

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In a screening exercise for ethanol-selective extraction solvents, partitioning of ethanol and water from a 5 wt% aqueous solution into several C8 – C18 carboxylic acids was studied. Results for the acids are compared with those from alcohols of similar structure. In all cases studied, the acids exh...

  7. Engineering topology and kinetics of sucrose metabolism in Saccharomyces cerevisiae for improved ethanol yield.

    PubMed

    Basso, Thiago O; de Kok, Stefan; Dario, Marcelo; do Espirito-Santo, Júlio Cézar A; Müller, Gabriela; Schlölg, Paulo S; Silva, Carlos P; Tonso, Aldo; Daran, Jean-Marc; Gombert, Andreas K; van Maris, Antonius J A; Pronk, Jack T; Stambuk, Boris U

    2011-11-01

    Sucrose is a major carbon source for industrial bioethanol production by Saccharomyces cerevisiae. In yeasts, two modes of sucrose metabolism occur: (i) extracellular hydrolysis by invertase, followed by uptake and metabolism of glucose and fructose, and (ii) uptake via sucrose-proton symport followed by intracellular hydrolysis and metabolism. Although alternative start codons in the SUC2 gene enable synthesis of extracellular and intracellular invertase isoforms, sucrose hydrolysis in S. cerevisiae predominantly occurs extracellularly. In anaerobic cultures, intracellular hydrolysis theoretically enables a 9% higher ethanol yield than extracellular hydrolysis, due to energy costs of sucrose-proton symport. This prediction was tested by engineering the promoter and 5' coding sequences of SUC2, resulting in predominant (94%) cytosolic localization of invertase. In anaerobic sucrose-limited chemostats, this iSUC2-strain showed an only 4% increased ethanol yield and high residual sucrose concentrations indicated suboptimal sucrose-transport kinetics. To improve sucrose-uptake affinity, it was subjected to 90 generations of laboratory evolution in anaerobic, sucrose-limited chemostat cultivation, resulting in a 20-fold decrease of residual sucrose concentrations and a 10-fold increase of the sucrose-transport capacity. A single-cell isolate showed an 11% higher ethanol yield on sucrose in chemostat cultures than an isogenic SUC2 reference strain, while transcriptome analysis revealed elevated expression of AGT1, encoding a disaccharide-proton symporter, and other maltose-related genes. After deletion of both copies of the duplicated AGT1, growth characteristics reverted to that of the unevolved SUC2 and iSUC2 strains. This study demonstrates that engineering the topology of sucrose metabolism is an attractive strategy to improve ethanol yields in industrial processes. PMID:21963484

  8. PRODUCTION AND USE OF YEAST PECTOLYTIC ENZYMES TO AID PINEAPPLE JUICE EXTRACTION

    Microsoft Academic Search

    V. P. Dzogbefia; E. Amoke; J. H. Oldham; W. O. Ellis

    2001-01-01

    A crude preparation of pectolytic enzyme was obtained by culturing Saccharomyces cerevisiae (ATCC512712) in pineapple juice. Maximum cell growth was obtained on the 6th day after inoculation. Correspondingly, optimum protein concentration and enzyme activity were also observed on the 6th day old culture. Although not purified, the addition of this crude enzyme extract to crushed pineapple mash at 0.02% resulted

  9. Determination of Cd(II) and Cd-metallothioneins in biological extracts using baker’s yeast and inductively coupled plasma optical emission spectrometry

    Microsoft Academic Search

    Amauri A. Menegário; Paulo S. Tonello; Priscila A. Biscaro; Ana L. Brossi-Garcia

    2007-01-01

    .  The use of Saccharomyces cerevisiae as a sorbent material to separate Cd(II) and Cd-metallothionein complex (Cd-MT) has been explored. Solid–liquid phase extractions\\u000a were carried out in batch mode and the main parameters of the process (pH, temperature, time of incubation, amount of biomass\\u000a and analyte) were evaluated. Under optimized conditions, the yeast quantitatively retain (94 ? 5%) the Cd(II) while

  10. Pectin–sucrose–Ca 2+ interactions: effects on rheological properties

    Microsoft Academic Search

    M. H Norziah; S. S Kong; A Abd Karim; C. C Seow

    2001-01-01

    The effects of varying concentrations of pectin (4.5–6.5%, w\\/w), sucrose (40–60%, w\\/w) and calcium (20–60mg\\/g pectin) on the viscoelastic properties of pectin dispersions at pH 3.0 were investigated. Pectin samples used were extracted from pomelo fruit peels (Citrus grandis) grown in Malaysia. The dynamic rheological parameters (G?, G?, ? and ?*) of pectin–sucrose–calcium dispersion were determined at 1.5% strain from

  11. Ethanol production from syngas by Clostridium strain P11 using corn steep liquor as a nutrient replacement to yeast extract.

    PubMed

    Maddipati, Prasanth; Atiyeh, Hasan K; Bellmer, Danielle D; Huhnke, Raymond L

    2011-06-01

    The feasibility of replacing yeast extract (YE) by corn steep liquor (CSL), a low cost nutrient source, for syngas fermentation to produce ethanol using Clostridium strain P11 was investigated. About 32% more ethanol (1.7 g L(-1)) was produced with 20 g L(-1) CSL media in 250-mL bottle fermentations compared to media with 1 g L(-1) YE after 360 h. Maximum ethanol concentrations after 360 h of fermentation in a 7.5-L fermentor with 10 and 20 g L(-1) CSL media were 8.6 and 9.6 g L(-1), respectively, which represent 57% and 60% of the theoretical ethanol yields from CO. Only about 6.1 g L(-1) of ethanol was obtained in the medium with 1 g L(-1) YE after 360 h, which represents 53% of the theoretical ethanol yield from CO. The use of CSL also enhanced butanol production by sevenfold compared to YE in bottle fermentations. These results demonstrate that CSL can replace YE as the primary medium component and significantly enhance ethanol production by Clostridium strain P11. PMID:21474306

  12. Inhibitory Properties of Aqueous Ethanol Extracts of Propolis on Alpha-Glucosidase

    PubMed Central

    Zhang, Hongcheng; Wang, Guangxin; Beta, Trust; Dong, Jie

    2015-01-01

    The objective of the present study was to evaluate the inhibitory properties of various extracts of propolis on alpha-glucosidase from baker's yeast and mammalian intestine. Inhibitory activities of aqueous ethanol extracts of propolis were determined by using 4-nitrophenyl-D-glucopyranoside, sucrose and maltose as substrates, and acarbose as a positive reference. All extracts were significantly effective in inhibiting ?-glucosidase from baker's yeast and rat intestinal sucrase in comparison with acarbose (P < 0.05). The 75% ethanol extracts of propolis (75% EEP) showed the highest inhibitory effect on ?-glucosidase and sucrase and were a noncompetitive inhibition mode. 50% EEP, 95%, EEP and 100% EEP exhibited a mixed inhibition mode, while water extracts of propolis (WEP) and 25% EEP demonstrated a competitive inhibition mode. Furthermore, WEP presented the highest inhibitory activity against maltase. These results suggest that aqueous ethanol extracts of propolis may be used as nutraceuticals for the regulation of postprandial hyperglycemia. PMID:25767553

  13. Inhibitory properties of aqueous ethanol extracts of propolis on alpha-glucosidase.

    PubMed

    Zhang, Hongcheng; Wang, Guangxin; Beta, Trust; Dong, Jie

    2015-01-01

    The objective of the present study was to evaluate the inhibitory properties of various extracts of propolis on alpha-glucosidase from baker's yeast and mammalian intestine. Inhibitory activities of aqueous ethanol extracts of propolis were determined by using 4-nitrophenyl-D-glucopyranoside, sucrose and maltose as substrates, and acarbose as a positive reference. All extracts were significantly effective in inhibiting ?-glucosidase from baker's yeast and rat intestinal sucrase in comparison with acarbose (P < 0.05). The 75% ethanol extracts of propolis (75% EEP) showed the highest inhibitory effect on ?-glucosidase and sucrase and were a noncompetitive inhibition mode. 50% EEP, 95%, EEP and 100% EEP exhibited a mixed inhibition mode, while water extracts of propolis (WEP) and 25% EEP demonstrated a competitive inhibition mode. Furthermore, WEP presented the highest inhibitory activity against maltase. These results suggest that aqueous ethanol extracts of propolis may be used as nutraceuticals for the regulation of postprandial hyperglycemia. PMID:25767553

  14. Effects of vitamin D and yeast extract supplementation on turkey mortality and clostridial dermatitis incidence in a dexamethasone immunosuppression model.

    PubMed

    Huff, G R; Huff, W E; Ratha, N C

    2014-12-01

    Clostridial dermatitis (CD) is a production disease of commercial turkeys that is characterized by sudden mortality in market-aged male birds and by lesions that include fluid and air bubbles under the skin of the thigh, breast, and tail area. We have developed a model for CD using dexamethasone (Dex) injection that suggests this disease may be related to stressors during the last stages of turkey production. Male turkeys were provided with control feed and water or with feed supplemented with a commercial yeast extract (YE) product, water supplemented with vitamin D (VD), or the combination. At 6, 11, and 15 wk of age birds were treated with three intramuscular injections of Dex over a 5-day period. Both YE and VD, but not the combination, decreased early mortality. At week 7 mortality was increased by VD, and cellulitis lesions were seen in 7/8 mortalities. Mortality at week 12 was decreased by both YE and the combination of YE and VD, and cellulitis lesions were seen in 8/17 mortalities. There were no significant differences in mortality at week 16. Total mortality was 66 birds, and 23 of these had cellulitis lesions (38%). There were no YE-treated birds with CD lesions; however, 67% of VD-treated birds had CD lesions. This study suggests that feed supplementation with YE may improve the ability of turkeys to withstand the stressors during late production and provide protection against the development of CD; however, high levels of VD supplementation may be detrimental. PMID:25619002

  15. Evolution of plant sucrose uptake transporters.

    PubMed

    Reinders, Anke; Sivitz, Alicia B; Ward, John M

    2012-01-01

    In angiosperms, sucrose uptake transporters (SUTs) have important functions especially in vascular tissue. Here we explore the evolutionary origins of SUTs by analysis of angiosperm SUTs and homologous transporters in a vascular early land plant, Selaginella moellendorffii, and a non-vascular plant, the bryophyte Physcomitrella patens, the charophyte algae Chlorokybus atmosphyticus, several red algae and fission yeast, Schizosaccharomyces pombe. Plant SUTs cluster into three types by phylogenetic analysis. Previous studies using angiosperms had shown that types I and II are localized to the plasma membrane while type III SUTs are associated with vacuolar membrane. SUT homologs were not found in the chlorophyte algae Chlamydomonas reinhardtii and Volvox carterii. However, the characean algae Chlorokybus atmosphyticus contains a SUT homolog (CaSUT1) and phylogenetic analysis indicated that it is basal to all other streptophyte SUTs analyzed. SUTs are present in both red algae and S. pombe but they are less related to plant SUTs than CaSUT1. Both Selaginella and Physcomitrella encode type II and III SUTs suggesting that both plasma membrane and vacuolar sucrose transporter activities were present in early land plants. It is likely that SUT transporters are important for scavenging sucrose from the environment and intracellular compartments in charophyte and non-vascular plants. Type I SUTs were only found in eudicots and we conclude that they evolved from type III SUTs, possibly through loss of a vacuolar targeting sequence. Eudicots utilize type I SUTs for phloem (vascular tissue) loading while monocots use type II SUTs for phloem loading. We show that HvSUT1 from barley, a type II SUT, reverted the growth defect of the Arabidopsis atsuc2 (type I) mutant. This indicates that type I and II SUTs evolved similar (and interchangeable) phloem loading transporter capabilities independently. PMID:22639641

  16. Evolution of Plant Sucrose Uptake Transporters

    PubMed Central

    Reinders, Anke; Sivitz, Alicia B.; Ward, John M.

    2012-01-01

    In angiosperms, sucrose uptake transporters (SUTs) have important functions especially in vascular tissue. Here we explore the evolutionary origins of SUTs by analysis of angiosperm SUTs and homologous transporters in a vascular early land plant, Selaginella moellendorffii, and a non-vascular plant, the bryophyte Physcomitrella patens, the charophyte algae Chlorokybus atmosphyticus, several red algae and fission yeast, Schizosaccharomyces pombe. Plant SUTs cluster into three types by phylogenetic analysis. Previous studies using angiosperms had shown that types I and II are localized to the plasma membrane while type III SUTs are associated with vacuolar membrane. SUT homologs were not found in the chlorophyte algae Chlamydomonas reinhardtii and Volvox carterii. However, the characean algae Chlorokybus atmosphyticus contains a SUT homolog (CaSUT1) and phylogenetic analysis indicated that it is basal to all other streptophyte SUTs analyzed. SUTs are present in both red algae and S. pombe but they are less related to plant SUTs than CaSUT1. Both Selaginella and Physcomitrella encode type II and III SUTs suggesting that both plasma membrane and vacuolar sucrose transporter activities were present in early land plants. It is likely that SUT transporters are important for scavenging sucrose from the environment and intracellular compartments in charophyte and non-vascular plants. Type I SUTs were only found in eudicots and we conclude that they evolved from type III SUTs, possibly through loss of a vacuolar targeting sequence. Eudicots utilize type I SUTs for phloem (vascular tissue) loading while monocots use type II SUTs for phloem loading. We show that HvSUT1 from barley, a type II SUT, reverted the growth defect of the Arabidopsis atsuc2 (type I) mutant. This indicates that type I and II SUTs evolved similar (and interchangeable) phloem loading transporter capabilities independently. PMID:22639641

  17. Comparison of extraction methods for quantitation of methionine and selenomethionine in yeast by species specific isotope dilution gas chromatography-mass spectrometry.

    PubMed

    Yang, Lu; Sturgeon, Ralph E; McSheehy, Shona; Mester, Zoltán

    2004-11-01

    Fourteen extraction methods commonly cited in the literature were evaluated for the quantitation of methionine (Met) and selenomethionine (SeMet) in a yeast candidate certified reference material (CRM). Species specific isotope dilution (ID) gas chromatography-mass spectrometry (GC-MS) was utilized to effectively compensate for potential errors, such as losses during derivatization and clean up steps. Despite different extraction methods, the same derivatization procedure using methyl chloroformate was applied with a single exception, which was based on digestion with cyanogen bromide with 2% SnCl2 in 0.1 M HCl. Significant differences in measured Met and SeMet concentrations were obtained when different extraction methods were used. A 4 M methanesulfonic acid reflux digestion was found to be the most efficient for both analytes. Digestion with CNBr with 2% SnCl2 in 0.1 M HCl for the determination of SeMet showed the second highest extraction efficiency. Despite frequent use of enzymatic hydrolysis for the extraction of SeMet from yeast, very low extraction efficiencies for both analytes were obtained for four of eight tested methods. Among these, the highest extraction efficiencies for both analytes were obtained using 20mg pronase and 10mg lipase with incubation at 37 degrees C for 24 h. However, recoveries remained nearly 30 and 50% lower for Met and SeMet, respectively, compared to extraction with methanesulfonic acid. Lowest extraction efficiencies for both analytes were obtained when HCl or tetramethylammonium hydroxide (TMAH) digestions were used. Efficient extraction was also achieved using 200 mg (or 400 mg) of protease XIV with incubation at 37 degrees C for 72 h (or 24 h). Concentrations of 3331+/-45 and 3334+/-39 microg g(-1) (mean and one standard deviation, n = 4) for SeMet were obtained using 200 mg (72 h incubation) and 400 mg (24 h incubation) of protease XIV, respectively, in agreement with a value of 3404+/-38 microg g(-1) obtained using a methanesulfonic acid reflux. PMID:15560494

  18. Protein phosphatase activity and sucrose-mediated induction of fructan synthesis in wheat.

    PubMed

    Martínez-Noël, Giselle M A; Tognetti, Jorge A; Salerno, Graciela L; Wiemken, Andres; Pontis, Horacio G

    2009-10-01

    In this work, we analyze protein phosphatase (PP) involvement in the sucrose-mediated induction of fructan metabolism in wheat (Triticum aestivum). The addition of okadaic acid (OA), a PP-inhibitor, to sucrose-fed leaves reduced fructosylsucrose-synthesizing activity (FSS) induction in a dose-dependent manner. The expression of the two enzymes that contribute to FSS activity, 1-SST (1-sucrose:sucrose fructosyltransferase, E.C. 2.4.1.99) and 6-SFT (6-sucrose:fructan fructosyltransferase, E.C. 2.4.1.10), was blocked by 1 microM OA. These results suggest the involvement of a PP type 2A in sucrose signaling leading to fructan synthesis. OA addition to the feeding medium impaired both sucrose accumulation in leaves and the expression of sucrose-H+ symporter (SUT1). It is known that sucrose concentration must exceed a threshold for the induction of fructan metabolism; hence PP2A inhibition may result in lower sucrose levels than required for this induction. OA also induced the vacuolar acid invertase (acid INV) transcript levels suggesting that PP activity might play a role in carbon partitioning. Total extractable PP2A activity decreased during 24 h of treatment with sucrose, in parallel with declining sugar uptake into leaf tissues. In conclusion, our results suggest that PP2A is involved in sucrose-induction of fructan metabolism and may play a role in regulating sucrose uptake, but do not rule out that further steps in sucrose signaling pathway may be affected. PMID:19714360

  19. Metabolism of sucrose and its five isomers by Fusobacterium mortiferum.

    PubMed

    Pikis, Andreas; Immel, Stefan; Robrish, Stanley A; Thompson, John

    2002-03-01

    Fusobacterium mortiferum utilizes sucrose [glucose-fructose in alpha(1-->2) linkage] and its five isomeric alpha-D-glucosyl-D-fructoses as energy sources for growth. Sucrose-grown cells are induced for both sucrose-6-phosphate hydrolase (S6PH) and fructokinase (FK), but the two enzymes are not expressed above constitutive levels during growth on the isomeric compounds. Extracts of cells grown previously on the sucrose isomers trehalulose alpha(1-->1), turanose alpha(1-->3), maltulose alpha(1-->4), leucrose alpha(1-->5) and palatinose alpha(1-->6) contained high levels of an NAD+ plus metal-dependent phospho-alpha-glucosidase (MalH). The latter enzyme was not induced during growth on sucrose. MalH catalysed the hydrolysis of the 6'-phosphorylated derivatives of the five isomers to yield glucose 6-phosphate and fructose, but sucrose 6-phosphate itself was not a substrate. Unexpectedly, MalH hydrolysed both alpha- and beta-linked stereomers of the chromogenic analogue p-nitrophenyl glucoside 6-phosphate. The gene malH is adjacent to malB and malR, which encode an EII(CB) component of the phosphoenolpyruvate-dependent sugar:phosphotransferase system and a putative regulatory protein, respectively. The authors suggest that for F. mortiferum, the products of malB and malH catalyse the phosphorylative translocation and intracellular hydrolysis of the five isomers of sucrose and of related alpha-linked glucosides. Genes homologous to malB and malH are present in both Klebsiella pneumoniae and the enterohaemorrhagic strain Escherichia coli O157:H7. Both these organisms grew well on sucrose, but only K. pneumoniae exhibited growth on the isomeric compounds. PMID:11882720

  20. Analysis of sucrose from sugar beet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sucrose is a disaccharide composed of the monosaccharides glucose and fructose. Sucrose is a product of photosynthesis and is a key carbohydrate resource for growth and metabolism in many organisms. Economic sources of sucrose include sugar cane and sugar beet, where fresh weight sucrose concentrati...

  1. Use of high-ethanol-resistant yeast isolates from Nigerian palm wine in lager beer brewing

    Microsoft Academic Search

    R. C. Agu; T. U. Anyanwu; A. H. Onwumelu

    1993-01-01

    High-ethanol-resistant yeasts, characterized as Saccharomyces sp., were isolated from Nigerian palm wine with added sucrose for high gravity brewing. The yeast isolates that survived the highest ethanol production were used to ferment brewery wort and produced 8.2 to 8.5% (v\\/v) ethanol; values almost double that of the control yeast from a local brewery.

  2. Effects of added chelated trace minerals, organic selenium, yeast culture, direct-fed microbials, and Yucca schidigera extract in horses: II. Nutrient excretion and potential environmental impact.

    PubMed

    Gordon, M E; Edwards, M S; Sweeney, C R; Jerina, M L

    2013-08-01

    The objective of this study was to test the hypothesis that an equine diet formulated with chelated trace minerals, organic selenium, yeast culture, direct-fed microbials (DFM) and Yucca schidigera extract would decrease excretion of nutrients that have potential for environmental impact. Horses were acclimated to 100% pelleted diets formulated with (ADD) and without (CTRL) the aforementioned additives. Chelated sources of Cu, Zn, Mn, and Co were included in the ADD diet at a 100% replacement rate of sulfate forms used in the CTRL diet. Additionally, the ADD diet included organic selenium yeast, DFM, and Yucca schidigera extract. Ten horses were fed the 2 experimental diets during two 42-d periods in a crossover design. Total fecal and urine collection occurred during the last 14 d of each period. Results indicate no significant differences between Cu, Zn, Mn, and Co concentrations excreted via urine (P > 0.05) due to dietary treatment. There was no difference between fecal Cu and Mn concentrations (P > 0.05) based on diet consumed. Mean fecal Zn and Co concentrations excreted by horses consuming ADD were greater than CTRL (P < 0.003). Differences due to diet were found for selenium fecal (P < 0.0001) and urine (P < 0.0001) excretions, with decreased concentrations found for horses consuming organic selenium yeast (ADD). In contrast, fecal K (%) was greater (P = 0.0421) for horses consuming ADD, whereas concentrations of fecal solids, total N, ammonia N, P, total ammonia, and fecal output did not differ between dietary treatments (P > 0.05). In feces stockpiled to simulate a crude composting method, no differences (P > 0.05) due to diet were detected for particle size, temperature, moisture, OM, total N, P, phosphate, K, moisture, potash, or ammonia N (P > 0.05). Although no difference (P = 0.2737) in feces stockpile temperature due to diet was found, temperature differences over time were documented (P < 0.0001). In conclusion, the addition of certain chelated mineral sources, organic Se yeast, DFM, and Yucca schidigera extract did not decrease most nutrient concentrations excreted. Horses consuming organic selenium as part of the additive diet had lower fecal and urine Se concentrations, as well as greater fecal K concentrations. PMID:23881677

  3. In vitro evaluation of the antimicrobial activity of eugenol, limonene, and citrus extract against bacteria and yeasts, representative of the spoiling microflora of fruit juices.

    PubMed

    Bevilacqua, Antonio; Corbo, Maria Rosaria; Sinigaglia, Milena

    2010-05-01

    This article reports on the investigation on the bioactivity of eugenol, limonene, and citrus extract against three bacteria (Lactobacillus plantarum, Lactobacillus brevis, and Bacillus coagulans) and three yeasts (Saccharomyces bayanus, Pichia membranifaciens, and Rhodotorula bacarum), representing the spoilage microflora of fruit juices. The experiments were performed with laboratory media by using a microdilution method. Data were fitted using the Gompertz equation, and the kinetic parameters were used to evaluate the MIC and the dose-dependent effect (at suboptimal doses for each essential oil). Citrus extract was the most effective essential oil, and the results suggested the following susceptibility hierarchy, from the most sensitive microorganism to the most resistant one (values in parentheses represent MICs): S. bayanus (2 ppm) > R. bacarum (3 ppm) > P. membranifaciens (5 ppm) > B. coagulans (cells, 20 ppm) > L. brevis (40 ppm) > L. plantarum (>40 ppm). PMID:20501040

  4. Response of scab-susceptible (McIntosh) and scab-resistant (Liberty) apple tissues to treatment with yeast extract and Venturia inaequalis.

    PubMed

    Hrazdina, Geza; Borejsza-Wysocki, W

    2003-09-01

    Yeast extract and Venturia inaequalis treated intact scab-susceptible (McIntosh) and scab-resistant (Liberty) apple plants and their organs were analyzed for phenolic metabolites. The major phenolic compounds found in both non-treated and treated leaves were phloridzin and phloretin which accumulated in mM concentrations. Untreated and treated stems and roots contained only phloridzin as the major detectable metabolite during the course of the investigation. The accumulation of phloridzin and phloretin was not developmentally regulated, since they were present in both young and old leaves, and also in the intercellular washings of both scab-susceptible and scab-resistant plants. The major metabolites of both McIntosh and Liberty fruits were cinnamyl glucose and p-coumarylquinic acid, which increased 20-fold in Liberty fruit upon yeast extract treatment. The same compounds increased only 2-fold in McIntosh fruits. Minor compounds in the fruits of both cultivars were p-coumaric acid, phloridzin and phloretin, the latter compound being present at the threshold of detection. Biphenyl and dibenzofuran compounds, the major metabolites of elicitor treated Liberty cell suspension cultures, could not be detected in the intact plants. These results indicate differential response of plant organs and cell suspension cultures to elicitor treatment or pathogen invasion. PMID:12943766

  5. Sucrose phosphate synthase and sucrose phosphate phosphatase interact in planta and promote plant growth and biomass accumulation

    PubMed Central

    Maloney, Victoria J.; Park, Ji-Young; Unda, Faride; Mansfield, Shawn D.

    2015-01-01

    Bioinformatic analysis indicates that sucrose phosphate synthase (SPS) contains a putative C-terminal sucrose phosphate phosphatase (SPP)-like domain that may facilitates the binding of SPP. If an SPS–SPP enzyme complex exists, it may provide sucrose biosynthesis with an additional level of regulation, forming a direct metabolic channel for sucrose-6-phosphate between these two enzymes. Herein, the formation of an enzyme complex between SPS and SPP was examined, and the results from yeast two-hybrid experiments suggest that there is indeed an association between these proteins. In addition, in planta bioluminescence resonance energy transfer (BRET) was observed in Arabidopsis seedlings, providing physical evidence for a protein interaction in live cells and in real time. Finally, bimolecular fluorescence complementation (BiFC) was employed in an attempt to detect SPS–SPP interactions visually. The findings clearly demonstrated that SPS interacts with SPP and that this interaction impacts soluble carbohydrate pools and affects carbon partitioning to starch. Moreover, a fusion construct between the two genes promotes plant growth in both transgenic Arabidopsis and hybrid poplar. PMID:25873678

  6. Sucrose phosphate synthase and sucrose phosphate phosphatase interact in planta and promote plant growth and biomass accumulation.

    PubMed

    Maloney, Victoria J; Park, Ji-Young; Unda, Faride; Mansfield, Shawn D

    2015-07-01

    Bioinformatic analysis indicates that sucrose phosphate synthase (SPS) contains a putative C-terminal sucrose phosphate phosphatase (SPP)-like domain that may facilitates the binding of SPP. If an SPS-SPP enzyme complex exists, it may provide sucrose biosynthesis with an additional level of regulation, forming a direct metabolic channel for sucrose-6-phosphate between these two enzymes. Herein, the formation of an enzyme complex between SPS and SPP was examined, and the results from yeast two-hybrid experiments suggest that there is indeed an association between these proteins. In addition, in planta bioluminescence resonance energy transfer (BRET) was observed in Arabidopsis seedlings, providing physical evidence for a protein interaction in live cells and in real time. Finally, bimolecular fluorescence complementation (BiFC) was employed in an attempt to detect SPS-SPP interactions visually. The findings clearly demonstrated that SPS interacts with SPP and that this interaction impacts soluble carbohydrate pools and affects carbon partitioning to starch. Moreover, a fusion construct between the two genes promotes plant growth in both transgenic Arabidopsis and hybrid poplar. PMID:25873678

  7. Expression of the PmSUC1 sucrose carrier gene from Plantago major L. is induced during seed development

    Microsoft Academic Search

    Manfred Gahrtz; Elmon Schmelzer; Jurgen Stolz; Norbert Sauer

    1996-01-01

    A cDNA clone of the plasma membrane sucrose-H+sym- porter PmSUC1 from Plantago major L. has been isolated and expressed in Saccharomyces cerevisiae. The PmSUC1 protein was characterized in transgenic yeast and in proteoliposomes with an artificial proton-motive-force (pmf) generator. PmSUC1 catalyzes the active uptake of sucrose or maltose in the presence of pmf and is sensitive to uncouplers. Unlike the

  8. Could yeast infections impair recovery from mental illness? A case study using micronutrients and olive leaf extract for the treatment of ADHD and depression.

    PubMed

    Rucklidge, Julia J

    2013-01-01

    Micronutrients are increasingly used to treat psychiatric disorders including attention-deficit/hyperactivity disorder (ADHD), mood disorders, stress, and anxiety. However, a number of factors influence optimal response and absorption of nutrients, including the health of the gut, particularly the presence of yeast infections, such as Candida. As part of a wider investigation into the impact of micronutrients on psychiatric symptoms, many participants who experienced a yeast infection during their treatment showed a diminished response to the micronutrients. One case was followed systematically over a period of 3 y with documentation of deterioration in psychiatric symptoms (ADHD and mood) when infected with Candida and then symptom improvement following successful treatment of the infection with olive leaf extract (OLE) and probiotics. This case outlines that micronutrient treatment might be severely compromised by infections such as Candida and may highlight the importance of gut health when treating psychiatric disorders with nutrients. Given the role that inflammation can play in absorption of nutrients, it was hypothesized that the infection was impairing absorption of the micronutrients. PMID:23784606

  9. Discovery of N(2)-(1-carboxyethyl)guanosine 5'-monophosphate as an umami-enhancing maillard-modified nucleotide in yeast extracts.

    PubMed

    Festring, Daniel; Hofmann, Thomas

    2010-10-13

    Sensory-guided fractionation of a commercial yeast extract involving medium-pressure RP-18 chromatography and ion-pair chromatography, followed by LC-MS/MS, LC-TOF-MS, 1D/2D-NMR, and CD spectroscopy, led to the discovery of the previously not reported umami-enhancing nucleotide diastereomers (R)- and (S)-N(2)-(1-carboxyethyl)guanosine 5'-monophosphate. Model experiments confirmed the formation of these diastereomers by a Maillard-type glycation of guanosine 5'-monophosphate with dihydroxyacetone and glyceraldehyde, respectively. Sensory studies revealed umami recognition threshold concentrations of 0.19 and 0.85 mmol/L for the (S)- and (R)-configured diastereomers, respectively, and demonstrated the taste-enhancing activity of these nucleotides on monosodium l-glutamate solutions. PMID:20839805

  10. Identification of selenium-containing proteins in selenium-rich yeast aqueous extract by 2D gel electrophoresis, nanoHPLC–ICP MS and nanoHPLC–ESI MS\\/MS

    Microsoft Academic Search

    Laure Tastet; Dirk Schaumlöffel; Brice Bouyssiere; Ryszard Lobinski

    2008-01-01

    An approach based on the consecutive use of nanoHPLC–ICP collision cell MS and nanoHPLC–electrospray MS was proposed for the analysis of water-soluble selenium-containing proteins in selenium-rich yeast after their separation by 2D gel electrophoresis (GE). An ultrasonic probe was employed for fast protein extraction avoiding sample heating and thus reducing the risk of protein degradation. The efficiency of different extraction

  11. Featured Molecules: Sucrose and Vanillin

    NASA Astrophysics Data System (ADS)

    Coleman, William F.; Wildman, Randall J.

    2003-04-01

    The WebWare molecules of the month for April relate to the sense of taste. Apple Fool, the JCE Classroom Activity, mentions sucrose and vanillin and their use as flavorings. Fully manipulable (Chime) versions of these and other molecules are available at Only@JCE Online.

  12. Differential extraction of soluble pools from the cytosol and the vacuoles of yeast ( Candida utilis ) using DEAE-dextran

    Microsoft Academic Search

    V. Huber-Wälchli; A. Wiemken

    1979-01-01

    The plasma membrane of Candida utilis cells was rapidly disrupted by a small dose of DEAE-dextran. The vacuolar membranes, in contrast, remained intact under isotonic conditions. Therefore, the cytosolic pool could be extracted in a first step, and in a second step, after disruption of the vacuoles, the vacuolar pool. The two extracts were studied in cells grown on different

  13. Sucrose-Metabolizing Enzymes in Transport Tissues and Adjacent Sink Structures in Developing Citrus Fruit 1

    PubMed Central

    Lowell, Cadance A.; Tomlinson, Patricia T.; Koch, Karen E.

    1989-01-01

    Juice tissues of citrus lack phloem; therefore, photosynthates enroute to juice sacs exit the vascular system on the surface of each segment. Areas of extensive phloem unloading and transport (vascular bundles + segment epidermis) can thus be separated from those of assimilate storage (juice sacs) and adjacent tissues where both processes occur (peel). Sugar composition, dry weight accumulation, and activities of four sucrose-metabolizing enzymes (soluble and cell-wall-bound acid invertase, alkaline invertase, sucrose synthase, and sucrose phosphate synthase) were measured in these transport and sink tissues of grapefruit (Citrus paradisi Macf.) to determine more clearly whether a given enzyme appeared to be more directly associated with assimilate transport versus deposition or utilization. Results were compared at three developmental stages. Activity of sucrose (per gram fresh weight and per milligram protein) extracted from zones of extensive phloem unloading and transport was significantly greater than from adjacent sink tissues during the stages (II and III) when juice sacs grow most rapidly. In stage II fruit, activity of sucrose synthase also significantly surpassed that of all other sucrose-metabolizing enzymes in extracts from the transport tissues (vascular bundles + segment epidermis). In contrast, sucrose phosphate synthase and alkaline invertase at this stage of growth were the most active enzymes from adjacent, rapidly growing, phloem-free sink tissues (juice sacs). Activity of these two enzymes in extracts from juice sacs was significantly greater than that form the transport tissues (vascular bundles + segment epidermis). Soluble acid invertase was the most active enzyme in extracts from all tissues of very young fruit (stage I), including nonvascular regions, but nearly disappeared prior to the onset of juice sac sugar accumulation. The physiological function of high sucrose synthase activity in the transport tissues during rapid sucrose import remains to be determined. PMID:16666942

  14. Vacuolar Acid Hydrolysis as a Physiological Mechanism for Sucrose Breakdown 1

    PubMed Central

    Echeverria, Ed; Burns, Jacqueline K.

    1989-01-01

    Sucrose breakdown in mature acidic `Persian' limes (Citrus aurantifolia [Christm.] Swing.) occurred at a rate of 30.6 picomoles per milliliter per day during 9 weeks storage at 15°C. Neither enzyme of sucrose catabolism (sucrose synthase or acid/alkaline invertase) was present in extracts of mature storage tissue. The average vacuolar pH, estimated by direct measurement of sap from isolated vacuoles and by the methylamine method, was about 2.0 to 2.2. In vitro acid hydrolysis of sucrose at physiological concentrations in a buffered solution (pH 2.2) occurred at identical rates as in matured limes. The results indicate that sucrose breakdown in stored mature acidic limes occurs by acid hydrolysis. PMID:16666803

  15. Sucrose Uptake by Developing Soybean Cotyledons 1

    PubMed Central

    Lichtner, Francis T.; Spanswick, Roger M.

    1981-01-01

    Sucrose uptake by excised developing soybean cotyledons shows a biphasic dependence on sucrose concentration. At concentrations less than about 50 millimolar external sucrose, uptake can be described as a carrier-mediated process, with a Km of 8 millimolar. At higher external sucrose concentrations, a linear dependence becomes apparent, which suggests the participation of a nonsaturable component in total uptake. Sucrose absorption is dependent on the presence of an electrochemical potential gradient for protons since agents interfering with the generation or maintenance of this gradient (NaN3 or carbonylcyanide-m-chlorophenyl hydrazone) decrease sucrose transport to a level at or below that predicted from the operation of the noncarrier-mediated process alone. The saturable component of sucrose uptake is also sensitive to the sulfhydryl-modifying compounds N-ethylmaleimide and p-chloro-mercuribenzenesulfonate. The thiol-reducing agent diethioerythritol reverses fully the p-chloro-mercuri-benzenesulfonate inhibition, but not that of N-ethyl maleim de. Sucrose transport is sensitive to external pH, being decreased at high pH0. Since sucrose-induced depolarization of the membrane potential and carrier-mediated sucrose influx show similar pH-dependence, inhibitor sensitivity, and values of Km for sucrose, a sucrose/proton contransport process appears to operate in developing soybean cotyledon cells. Measurement of free space and intracellular sucrose concentrations in vivo suggests that the carrier-mediated process is fully saturated and that sucrose transport may be limiting for sucrose accumulation by the developing seed. Images PMID:16661981

  16. A yeast bioassay for direct measurement of thyroid hormone disrupting effects in water without sample extraction, concentration, or sterilization.

    PubMed

    Li, Jian; Ren, Shujuan; Han, Shaolun; Li, Na

    2014-04-01

    The present study introduces an improved yeast bioassay for rapid yet sensitive evaluation of thyroid hormone disruption at the level of thyroid receptor (TR) in environmental water samples. This assay does not require water sample preparation and thus requires very little hands-on time. Based on different ?-galactosidase substrates, two modified bioassays, a colorimetric bioassay and a chemiluminescent bioassay, were developed. The compounds tested included the known thyroid hormone 3,3',5-triiodo-l-thyronine (T3), the specific TR antagonist amiodarone hydrochloride (AH) and phthalate esters (PAEs), which potentially disrupt thyroid hormone signaling. The EC50 values for T3 were similar to those previously obtained using a 96-well plate bioassay. TR antagonism by AH was studied in the presence of 2.5 × 10(-7)M T3, and the concentration producing 20% of the maximum effect (RIC20) for AH was 3.1 × 10(-7)M and 7.8 × 10(-9)M for the colorimetric bioassay and chemiluminescent bioassay, respectively. None of the tested PAEs induced ?-galactosidase expression, but diethylhexyl phthalate, benzyl butyl phthalate and dibutyl phthalate demonstrated TR antagonism. Furthermore, water samples collected from Guanting reservoir in Beijing were evaluated. Although TR agonism was not observed, antagonism was detected in all water samples and is expressed as AH equivalents. The toxicology equivalent quantity values obtained by the chemiluminescent bioassay ranged from 21.2 ± 1.6 to 313.9 ± 28.8 ?g L(-1) AH, and similar values were obtained for the colorimetric bioassay. The present study shows that the modified yeast bioassay can be used as a valuable tool for quantification of thyroid hormone disrupting effects in environmental water samples. PMID:24355165

  17. Sucrose Synthase in Wild Tomato, Lycopersicon chmielewskii, and Tomato Fruit Sink Strength

    PubMed Central

    Sun, Jindong; Loboda, Tadeusz; Sung, Shi-Jean S.; Black, Clanton C.

    1992-01-01

    Here it is reported that sucrose synthase can be readily measured in growing wild tomato fruits (Lycopersicon chmielewskii) when suitable methods are adopted during fruit extraction. The enzyme also was present in fruit pericarp tissues, in seeds, and in flowers. To check for novel characteristics, the wild tomato fruit sucrose synthase was purified, by (NH4)2SO4 fraction and chromatography with DE-32, Sephadex G-200, and PBA-60, to one major band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The following characteristics were obtained: native protein relative molecular weight 380,000; subunit relative molecular weight 89,000; Km values with: sucrose 53 millimolar, UDP 18.9 micromolar, UDP-glucose 88 micromolar, fructose 8.4 millimolar; pH optima between 6.2 to 7.3 for sucrose breakdown and 7 to 9 for synthesis; and temperature optima near 50°C. The enzyme exhibited a high affinity and a preference for uridylates. The enzyme showed more sensitivity to divalent cations in the synthesis of sucrose than in its breakdown. Sink strength in tomato fruits also was investigated in regard to sucrose breakdown enzyme activities versus fruit weight gain. Sucrose synthase activity was consistently related to increases in fruit weight (sink strength) in both wild and commercial tomatoes. Acid and neutral invertases were not, because the published invertase activity values were too variable for quantitative analyses regarding the roles of invertases in tomato fruit development. In rapidly growing fruits of both wild and commercially developed tomato plants, the activity of sucrose synthase per growing fruit, i.e. sucrose synthase peak activity X fruit size, was linearly related to final fruit size; and the activity exceeded fruit growth and carbon import rates by at least 10-fold. In mature, nongrowing fruits, sucrose synthase activities approached nil values. Therefore, sucrose synthase can serve as an indicator of sink strength in growing tomato fruits. PMID:16668741

  18. Influence of autochthonous lactic acid bacteria and enzymatic yeast extracts on the microbiological, biochemical and sensorial properties of Lben generic products.

    PubMed

    Mangia, Nicoletta P; Garau, Giovanni; Murgia, Marco A; Bennani, Abdelmajid; Deiana, Pietrino

    2014-05-01

    In this study we identified Lactococcus lactis subsp. lactis, Lc. lactis subsp. lactis biovar diacetylactis, Kluyveromices lactis and Saccharomyces cerevisiae as the dominant microorganisms of traditional Moroccan acid-alcoholic fermented milk named Lben. The low pH (3·8±0·3), lactose (16·8±3·4 mg/l) and lactic acid (8·16±0·6 mg/l) content indicated that a strong fermentation occurred in the traditional product which was also characterised by the substantial presence of ethanol and typical volatile carbonyl compounds (i.e., acetoin, diacetyl and acetaldehyde). Microbiological analyses of experimental Lben manufactured with selected strains (isolated from the traditional product) of Lc. lactis subsp. lactis and Lc. lactis subsp. lactis biovar. diacetylactis alone (batch A) and in combination with enzymatic extract of a K. lactis strain (batch B) indicated a good effectiveness of the starters employed (?1010 CFU/g of lactococci after 8 h of incubation) and a significant effect of the yeast enzyme extract on lactococci viability. Despite slight changes in the physicochemical characteristics of the two Lben during the 15 d storage period, volatile compounds (i.e. ethanol, acetaldehyde, diacetyl and acetoin) were consistently higher in batch B. Moreover, sensorial analysis performed after 15 d of storage, highlighted higher odour and flavour intensity, vegetable odour and viscosity in batch B while batch A displayed higher astringency. PMID:24642233

  19. Interaction of structural isomers of sucrose in the reaction between sucrose and glucosyltransferases from mutans streptococci.

    PubMed

    Minami, T; Fujiwara, T; Ooshima, T; Nakajima, Y; Hamada, S

    1990-08-01

    Structural isomers of sucrose, i.e. disaccharides composed of glucose and fructose molecules with different glucosidic linkages, were examined for their effect on the reaction between sucrose and various glucosyltransferases (GTases) from Streptococcus mutans MT8148 and Streptococcus sobrinus 6715. Trehalulose (alpha 1-1), turanose (alpha 1-3), maltulose (alpha 1-4), and palatinose (alpha 1-6) were used as the sucrose analogues. Mutans streptococci were found not to utilize these sucrose analogues. Analysis of enzymatic products of GTase and sucrose with thin layer chromatography clearly revealed that glucan synthesis from [14C]sucrose by the various purified GTase preparations from S. mutans and S. sobrinus was inhibited in the presence of these sucrose analogues except turanose, resulting in the release of increased amounts of [14C]fructose and [14C]oligosaccharides. It was also found that the fructose residues in the oligosaccharides were derived from those of sucrose analogues but not sucrose itself. The Lineweaver-Burk plots of the substrate saturation kinetics of GTase vs sucrose indicated increased Km and Vmax in the presence of sucrose analogue, as compared with sucrose alone. Finally, these sucrose analogues except turanose inhibited sucrose dependent cellular adherence of S. sobrinus 6715 to a glass surface, while they scarcely inhibited the adherence of S. mutans MT8148. Among the analogues, maltulose appeared the most effective inhibitor against GTases in general. PMID:2150553

  20. Sucrose transport into stalk tissue of sugarcane

    SciTech Connect

    Thom, M.; Maretzki, A. (Hawaiian Sugar Planters' Association, Aiea, HI (USA))

    1990-05-01

    The productivity of higher plants is, in part, dependent on transport of photosynthate from source to sink (in sugarcane, stalk) and upon its assimilation in cells of the sink tissue. In sugarcane, sucrose has been reported to undergo hydrolysis in the apoplast before uptake into the storage parenchyma, whereas recently, sucrose was reported to be taken up intact. This work was based on lack of randomization of ({sup 14}C)fructosyl sucrose accumulated after feeding tissue slices with this sugar. In this report, we present evidence from slices of stalk tissue that sucrose is taken up intact via a carrier-mediated, energy-dependent process. The evidence includes: (1) uptake of fluorosucrose, an analog of sucrose not subject to hydrolysis by invertase; (2) little or no randomization of ({sup 14}C) fructosyl sucrose taken up; (3) the presence of a saturable as well as a linear component of sucrose uptake; and (4) inhibition of both the saturable and linear components of sucrose uptake by protonophore and sulhydryl agents. Hexoses can also be taken up, and at a greater efficiency than sucrose. It is probable that both hexose and sucrose can be transported across the plasma membrane, depending on the physiological status of the plant.

  1. Efficacy of marine yeasts and baker's yeast as immunostimulants in Fenneropenaeus indicus: A comparative study

    Microsoft Academic Search

    P. J. Sarlin; Rosamma Philip

    2011-01-01

    Efficacy of marine yeasts Debaryomyces hansenii (S8) and Candida tropicalis (S186) as immunostimulants to Indian white prawn Fenneropenaeus indicus was estimated in comparison with Saccharomyces cerevisiae S36. Biomass of yeast strains was prepared using Malt Extract Agar and incorporated into a standard diet to prepare yeast diets of varying concentrations. F. indicus were fed these diets for a period of

  2. Protective effects of flavonoids and extract from Vellozia kolbekii Alves against oxidative stress induced by hydrogen peroxide in yeast.

    PubMed

    da Silva, Carmelita Gomes; Carvalho, Camilla Dayane F; Hamerski, Lidilhone; Castro, Frederico A V; Alves, Ruy José Válka; Kaiser, Carlos Roland; Eleutherio, Elis Cristina Araújo; de Rezende, Cláudia Moraes

    2012-04-01

    Two flavonoids 3,5,7,3',4'-pentahydroxy-6-prenylflavonol (1) and 3,5,7,3',4'-pentahydroxy-8-methyl-6-prenylflavonol (2) were isolated from the ethyl acetate extract of sheaths of Vellozia kolbekii Alves (Velloziaceae). This is the first time that compound 2 has been described. The crude extract and flavonoids were found to be active as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavengers and were able to the increase tolerance of the eukaryotic microorganism Saccharomyces cerevisiae to oxidative stress generated by H(2)O(2). The protective effect was correlated with a reduction in the oxidation of proteins and lipids. In addition, flavonoids isolated from Velloziaceae showed an inhibitory effect on mutations in p53, which is mutated and nonfunctional in more than 50% of cases of human cancer. PMID:21915628

  3. Molecular Control of Sucrose Utilization in Escherichia coli W, an Efficient Sucrose-Utilizing Strain

    PubMed Central

    Sabri, Suriana; Nielsen, Lars K.

    2013-01-01

    Sucrose is an industrially important carbon source for microbial fermentation. Sucrose utilization in Escherichia coli, however, is poorly understood, and most industrial strains cannot utilize sucrose. The roles of the chromosomally encoded sucrose catabolism (csc) genes in E. coli W were examined by knockout and overexpression experiments. At low sucrose concentrations, the csc genes are repressed and cells cannot grow. Removal of either the repressor protein (cscR) or the fructokinase (cscK) gene facilitated derepression. Furthermore, combinatorial knockout of cscR and cscK conferred an improved growth rate on low sucrose. The invertase (cscA) and sucrose transporter (cscB) genes are essential for sucrose catabolism in E. coli W, demonstrating that no other genes can provide sucrose transport or inversion activities. However, cscK is not essential for sucrose utilization. Fructose is excreted into the medium by the cscK-knockout strain in the presence of high sucrose, whereas at low sucrose (when carbon availability is limiting), fructose is utilized by the cell. Overexpression of cscA, cscAK, or cscAB could complement the W?cscRKAB knockout mutant or confer growth on a K-12 strain which could not naturally utilize sucrose. However, phenotypic stability and relatively good growth rates were observed in the K-12 strain only when overexpressing cscAB, and full growth rate complementation in W?cscRKAB also required cscAB. Our understanding of sucrose utilization can be used to improve E. coli W and engineer sucrose utilization in strains which do not naturally utilize sucrose, allowing substitution of sucrose for other, less desirable carbon sources in industrial fermentations. PMID:23124236

  4. Identification and classification of genes required for tolerance to high-sucrose stress revealed by genome-wide screening of Saccharomyces cerevisiae.

    PubMed

    Ando, Akira; Tanaka, Fumiko; Murata, Yoshinori; Takagi, Hiroshi; Shima, Jun

    2006-03-01

    Yeasts used in bread making are exposed to high concentrations of sucrose during sweet dough fermentation. Despite its importance, tolerance to high-sucrose stress is poorly understood at the gene level. To clarify the genes required for tolerance to high-sucrose stress, genome-wide screening was undertaken using the complete deletion strain collection of diploid Saccharomyces cerevisiae. The screening identified 273 deletions that yielded high sucrose sensitivity, approximately 20 of which were previously uncharacterized. These 273 deleted genes were classified based on their cellular function and localization of their gene products. Cross-sensitivity of the high-sucrose-sensitive mutants to high concentrations of NaCl and sorbitol was studied. Among the 273 sucrose-sensitive deletion mutants, 269 showed cross-sensitivities to sorbitol or NaCl, and four (i.e. ade5,7, ade6, ade8, and pde2) were specifically sensitive to high sucrose. The general stress response pathways via high-osmolarity glycerol and stress response element pathways and the function of the invertase in the ade mutants were similar to those in the wild-type strain. In the presence of high-sucrose stress, intracellular contents of ATP in ade mutants were at least twofold lower than that of the wild-type cells, suggesting that depletion of ATP is a factor in sensitivity to high-sucrose stress. The genes identified in this study might be important for tolerance to high-sucrose stress, and therefore should be target genes in future research into molecular modification for breeding of yeast tolerant to high-sucrose stress. PMID:16487347

  5. Xuezhikang, Extract of Red Yeast Rice, Improved Abnormal Hemorheology, Suppressed Caveolin-1 and Increased eNOS Expression in Atherosclerotic Rats

    PubMed Central

    Yang, Ya-Bing; Liu, Mei-Lin

    2013-01-01

    Background Xuezhikang is the extract of red yeast rice, which has been widely used for the management of atherosclerotic disease, but the molecular basis of its antiatherosclerotic effects has not yet been fully identified. Here we investigated the changes of eNOS in vascular endothelia and RBCs, eNOS regulatory factor Caveolin-1 in endothelia, and hemorheological parameters in atherosclerotic rats to explore the protective effects of Xuezhikang. Methodology/Principal Findings Wistar rats were divided into 4 groups (n?=?12/group) group C, controls; group M, high-cholesterol diet (HCD) induced atherosclerotic models; group X, HCD+Xuezhikang; and group L, HCD +Lovastatin. In group X, Xuezhikang inhibited oxidative stress, down-regulated caveolin-1 in aorta wall (P<0.05), up-regulated eNOS expression in vascular endothelia and erythrocytes (P<0.05), increased NOx (nitrite and nitrate) in plasma and cGMP in erythrocyte plasma and aorta wall (P<0.05), increased erythrocyte deformation index (EDI), and decreased whole blood viscosity and plasma viscosity (P<0.05), with the improvement of arterial pathology. Conclusions/Significance Xuezhikang up-regulated eNOS expression in vascular endothelia and RBCs, increased plasma NOx and improved abnormal hemorheology in high cholesterol diet induced atherosclerotic rats. The elevated eNOS/NO and improved hemorheology may be beneficial to atherosclerotic disease. PMID:23675421

  6. Dry yeast

    NSDL National Science Digital Library

    Ranveig Thattai (None; )

    2005-09-27

    Yeast is a type of eukaryotic organism that can live in a dormant state. It can be activated from its dormant state by water and sugar. The yeast uses the sugar to grow and produces carbon dioxide gas as a byproduct.

  7. Yeast virology

    Microsoft Academic Search

    REED B. WICKNER

    The three families of double-stranded RNA (dsRNA) viruses and two families of retroviruses (retrotranspo- sons) of the yeast Sacc\\/zaromyces cerevisiaeare all trans- mitted between cells only by cell fusion, probably re- flecting the high frequency of mating of yeast cells in nature. One dsRNA virus and two retroviruses appar- ently use ribosomal \\

  8. Isotopologue analysis of sugar phosphates in yeast cell extracts by gas chromatography chemical ionization time-of-flight mass spectrometry.

    PubMed

    Chu, Dinh Binh; Troyer, Christina; Mairinger, Teresa; Ortmayr, Karin; Neubauer, Stefan; Koellensperger, Gunda; Hann, Stephan

    2015-04-01

    Metabolic flux analysis is based on the measurement of isotopologue ratios. In this work, a new GC-MS-based method was introduced enabling accurate determination of isotopologue distributions of sugar phosphates in cell extracts. A GC-TOFMS procedure was developed involving a two-step online derivatization (ethoximation followed by trimethylsilylation) offering high mass resolution, high mass accuracy and the potential of retrospective data analysis typical for TOFMS. The information loss due to fragmentation intrinsic for isotopologue analysis by electron ionization could be overcome by chemical ionization with methane. A thorough optimization regarding pressure of the reaction gas, emission current, electron energy and temperature of the ion source was carried out. For a substantial panel of sugar phosphates both of the glycolysis and the pentose phosphate pathway, sensitive determination of the protonated intact molecular ions together with low abundance fragment ions was successfully achieved. The developed method was evaluated for analysis of Pichia pastoris cell extracts. The measured isotopologue ratios were in the range of 55:1-2:1. The comparison of the experimental isotopologue fractions with the theoretical fractions was excellent, revealing a maximum bias of 4.6% and an average bias of 1.4%. PMID:25673246

  9. A new beta-glucosidase producing yeast for lower-cost cellulosic ethanol production from xylose-extracted corncob residues by simultaneous saccharification and fermentation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conventional cellulose-to-ethanol conversion by simultaneous saccharification and fermentation (SSF)requires enzymatic saccharification using both cellulase and ß-glucosidase allowing cellulose utilization by common ethanologenic yeast. Here we report a new yeast strain of Clavispora NRRL Y-50464 th...

  10. Sucrose-mediated transcriptional regulation of sucrose symporter activity in the phloem.

    SciTech Connect

    Matt Vaughn Greg Harrington Daniel R Bush

    2002-08-06

    This project was based on our discovery that sucrose acts as a signaling molecule that regulates the activity of a proton-sucrose symporter in sugar beet leaf tissue. A major objective here was determining how sucrose transporter activity is being regulated. When sucrose accumulates in the phloem sucrose transport activity drops dramatically. Western blots of plasma membrane proteins isolated from sucrose treated leaves showed that the loss of sucrose transport activity was proportional to a decline in symporter abundance, demonstrating that sucrose transport is regulated by changes in the amount of BvSUT1 protein. BvSUT1 transcript levels decreased in parallel with the loss of sucrose transport activity. Nuclear run-on experiments demonstrated that BvSUT1 gene transcription was repressed significantly in nuclei from leaves fed 100 mM exogenous sucrose, showing that sucrose-dependent modulation of BvSUT1 mRNA levels is mediated by changes in transcription. To identify which secondary messenger systems might be involved in regulating symporter activity, we used a variety of pharmacological agents to probe for a role of calcium or protein phosphorylation in sucrose signaling. In a detailed analysis, only okadaic acid altered sucrose transport activity. These results suggest a protein phosphatase is involved. We hypothesized that protein kinase inhibitors would have a neutral affect or increase symporter transcription. Transpirational feeding of the protein kinase inhibitor staurosporine had no impact on sucrose transport while calphostin C, an inhibitor of protein kinase C, caused a 60% increase. These data provided good evidence that protein phosphorylation plays a central role in regulating sucrose symporter expression and sucrose transport activity. To determine whether protein phosphorylation is involved in sucrose regulation of proton-sucrose symporter activity, we pre-fed leaves with staurosporine for 4 h and then fed the treated leaves water or 100 mM sucrose for an additional 20 h. Sucrose transport activity was higher than the water control in both staurosporine/water- and staurosporine/sucrose-fed leaves. In contrast, sucrose transport activity was only 40% of the water control in sucrose-fed leaves. Taken together, these results showed that a phosphorylation-dependent signal transduction pathway is involved in sucrose-mediated regulation of BvSUT1 gene expression, sucrose transport activity, and ultimately phloem loading. Publications originating from this work: Vaughn MW, GN. Harrington, and DR Bush 2002. Sucrose-mediated transcriptional regulation of sucrose symporter activity in the phloem. Proc. Natl. Acad. Sci. USA 99:10876-10880 Ransom-Hodgkins W, MW Vaughn, and DR Bush 2003. Protein phosphorylation mediates a key step in sucrose-regulation of the expression and transport activity of a beet proton-sucrose symporter. Planta 217:483-489 Harrington GN and Bush DR 2003. The bifunctional role of hexokinase in metabolism and glucose signaling. Plant Cell 15: 2493-2496

  11. SUCROSE ACCUMULATION DURING EARLY SUGAR BEET DEVELOPMENT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study examined sucrose accumulation in different breeding lines during the first weeks after emergence in order to identify early morphological and physiological differences correlated with final root sucrose content. Six germplasm lines (US H20, SR87, SR95, SR96, SR97, and Syngenta-Hille...

  12. "Sucrose analgesia": absorptive mechanism or taste perception?

    PubMed Central

    Ramenghi, L.; Evans, D.; Levene, M.

    1999-01-01

    It remains unclear whether "sucrose analgesia" is related to a pre- or postabsorptive mechanism. In a double blind cross over study sucrose reduced the pain response of preterm infants exposed to heel prick blood samples only when it was administered into the mouth. It was ineffective when administered intragastrically.?? PMID:10325795

  13. A Systematic Review of Xuezhikang, an Extract from Red Yeast Rice, for Coronary Heart Disease Complicated by Dyslipidemia

    PubMed Central

    Shang, Qinghua; Liu, Zhaolan; Chen, Keji; Xu, Hao; Liu, Jianping

    2012-01-01

    Objective. This systematic review aims to evaluate the benefit and side effect of Xuezhikang for coronary heart disease (CHD) complicated by dyslipidemia. Methods. All randomized clinical trials (RCTs) with Xuezhikang as a treatment for CHD combined with dyslipidemia were considered for inclusion. Data extraction and analyses and quality assessment were conducted according to the Cochrane standards. Results. We included 22 randomized trials. Xuezhikang showed significant benefit on the incidence of all-cause deaths, CHD deaths, myocardial infarction, and revascularization as compared with placebo based on conventional treatment for CHD. It remarkably lowered total cholesterol (TC), triglyceride (TG), and low-density lipoprotein-cholesterol (LDL-C) as compared with the placebo or inositol nicotinate group, which was similar to statins group. Xuezhikang also raised high-density lipoprotein cholesterol (HDL-C) compared to placebo or no intervention, which was similar to Inositol nicotinate and slightly inferior to statins. The incidence of adverse events did not differ between the Xuezhikang and control group. Conclusions. Xuezhikang showed a comprehensive lipid-regulating effect and was safe and effective in reducing cardiovascular events in CHD patients complicated by dyslipidemia. However, more rigorous trials with high quality are needed to give high level of evidence. PMID:22567033

  14. Counting Yeast.

    ERIC Educational Resources Information Center

    Bealer, Jonathan; Welton, Briana

    1998-01-01

    Describes changes to a traditional study of population in yeast colonies. Changes to the procedures include: (1) only one culture per student team; (2) cultures are inoculated only once; and (3) the same tube is sampled daily. (DDR)

  15. Yeast Infections

    MedlinePLUS

    Candida is the scientific name for yeast. It is a fungus that lives almost everywhere, including in ... infection that causes white patches in your mouth Candida esophagitis is thrush that spreads to your esophagus, ...

  16. Yeast ecology of Kombucha fermentation.

    PubMed

    Teoh, Ai Leng; Heard, Gillian; Cox, Julian

    2004-09-01

    Kombucha is a traditional fermentation of sweetened tea, involving a symbiosis of yeast species and acetic acid bacteria. Despite reports of different yeast species being associated with the fermentation, little is known of the quantitative ecology of yeasts in Kombucha. Using oxytetracycline-supplemented malt extract agar, yeasts were isolated from four commercially available Kombucha products and identified using conventional biochemical and physiological tests. During the fermentation of each of the four products, yeasts were enumerated from both the cellulosic pellicle and liquor of the Kombucha. The number and diversity of species varied between products, but included Brettanomyces bruxellensis, Candida stellata, Schizosaccharomyces pombe, Torulaspora delbrueckii and Zygosaccharomyces bailii. While these yeast species are known to occur in Kombucha, the enumeration of each species present throughout fermentation of each of the four Kombucha cultures demonstrated for the first time the dynamic nature of the yeast ecology. Kombucha fermentation is, in general, initiated by osmotolerant species, succeeded and ultimately dominated by acid-tolerant species. PMID:15282124

  17. Sweet plasmonics: Sucrose macrocrystals of metal nanoparticles

    E-print Network

    Demir, Hilmi Volkan

    Sweet plasmonics: Sucrose macrocrystals of metal nanoparticles Talha Erdem1 , Zeliha Soran-Erdem1-Verlag Berlin Heidelberg 2014 KEYWORDS plasmonics, macrocrystals, metal nanoparticles, metal enhanced fluorescence, colloidal quantum dots ABSTRACT The realization of plasmonic structures generally necessitates

  18. Induction of Sucrose Utilization Genes from Bifidobacterium lactis by Sucrose and Raffinose

    Microsoft Academic Search

    Marla I. Trindade; Valerie R. Abratt; Sharon J. Reid

    2003-01-01

    The probiotic organism Bifidobacterium lactis was isolated from a yoghurt starter culture with the aim of analyzing its use of carbohydrates for the development of prebiotics. A sucrose utilization gene cluster of B. lactis was identified by complementation of a gene library in Escherichia coli. Three genes, encoding a sucrose phosphorylase (ScrP), a GalR-LacI-type transcriptional regulator (ScrR), and a sucrose

  19. Bacterial sucrose isomerases: properties and structural studies

    Microsoft Academic Search

    Moez Rhimi; Richard Haser; Nushin Aghajari

    2008-01-01

    Due to their significant role in food industry, sucrose isomerases are good candidates for rational protein engineering. Hence,\\u000a specific modifications in order to modify substrate affinity and selectivity, product specificity but also to adapt their\\u000a catalytic properties to particular industrial process conditions, is interesting. Our work on the structural studies of the\\u000a sucrose isomerase, MutB, which presents the first structural

  20. Effect of Fluoridated Sucrose on Rat Caries

    Microsoft Academic Search

    S. A. Mundorff; D. Glowinsky; C. J. Griffin; J. H. Stein; L. M. Gwinner

    1988-01-01

    The present study was designed to test the effect of frequent pulses of low fluoride levels on rat caries when supplied in a standardized cariogenic rat diet containing 67% sucrose (MIT-200). The test diets were variants of Diet MIT-200 in which the sucrose component had been fluoridated with NaF solution resulting in total concentrations of 0 (control), 2, 3, 5,

  1. Role of glucose signaling in yeast metabolism

    SciTech Connect

    Dam, K. van [Univ. of Amsterdam (Netherlands). E.C. Slater Inst.

    1996-10-05

    The conversion of glucose to ethanol and carbon dioxide by yeast was the first biochemical pathway to be studied in detail. The initial observation that this process is catalyzed by an extract of yeast led to the discovery of enzymes and coenzymes and laid the foundation for modern biochemistry. In this article, knowledge concerning the relation between uptake of and signaling by glucose in the yeast Saccharomyces cerevisiae is reviewed and compared to the analogous process in prokaryotes. It is concluded that (much) more fundamental knowledge concerning these processes is required before rational redesign of metabolic fluxes from glucose in yeast can be achieved.

  2. Effect of neem leaf extract and neem oil on Penicillium growth, sporulation, morphology and ochratoxin A production.

    PubMed

    Mossini, Simone A G; Arrotéia, Carla C; Kemmelmeier, Carlos

    2009-09-01

    In vitro trials were conducted to evaluate the effect of Azadirachtaindica (neem) extracts on mycelial growth, sporulation, morphology and ochratoxin A production by P. verrucosum and P. brevicompactum. The effect of neem oil extract from seeds and leaf was evaluated at 0.125; 0.25 and 0.5% and 6.25 and 12.5 mg/mL, respectively, in Yeast Extract Sucrose (YES) medium. Ochratoxin A production was evaluated by a thin-layer chromatography technique. Oil extracts exhibited significant (p ? 0.05) reduction of growth and sporulation of the fungi. No inhibition of ochratoxin A production was observed. Given its accessibility and low cost, neem oil could be implemented as part of a sustainable integrated pest management strategy for plant disease, as it has been shown to be fungitoxic by inhibition of growth and sporulation. PMID:22069528

  3. Sucrose synthase oligomerization and F-actin association are regulated by sucrose concentration and phosphorylation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sucrose synthase (SUS) is a key enzyme in plant metabolism, as it serves to cleave the photosynthetic end product sucrose into UDP-glucose and fructose. SUS is generally assumed to be a tetrameric protein, but results in the present study suggest that SUS can form dimers as well as tetramers and th...

  4. Expression of the yeast trehalose-6-phosphate synthase gene in transgenic tobacco plants: pleiotropic phenotypes include drought tolerance.

    PubMed

    Romero, C; Bellés, J M; Vayá, J L; Serrano, R; Culiáñez-Macià, F A

    1997-03-01

    The yeast trehalose-6-phosphate synthase gene (TPS1) was engineered under the control of the cauliflower mosaic virus regulatory sequences (CaMV35S) for expression in plants. Using Agrobacterium-mediated transfer, the gene was incorporated into the genomic DNA and constitutively expressed in Nicotiana tabacum L. plants. Trehalose was determined in the transformants, by anion-exchange chromatography coupled to pulsed amperometric detection. The non-reducing disaccharide accumulated up to 0.17 mg per g fresh weight in leaf extracts of transgenic plants. Trehaloseaccumulating plants exhibited multiple phenotypic alterations, including stunted growth, lancet-shaped leaves, reduced sucrose content and improved drought tolerance. These pleiotropic effects, and the fact that water loss from detached leaves was not significantly affected by trehalose accumulation, suggest that synthesis of this sugar, rather than leading to an osmoprotectant effect, had altered sugar metabolism and regulatory pathways affecting plant development and stress tolerance. PMID:19343407

  5. Ultrasonic velocity in water-ethanol-sucrose mixtures during alcoholic fermentation.

    PubMed

    Resa, P; Elvira, L; Montero de Espinosa, F; Gómez-Ullate, Y

    2005-02-01

    During alcoholic fermentation, sucrose and water are transformed into ethanol and carbon dioxide by the action of yeast enzymes. The measurement of the velocity of an ultrasonic pulse travelling through a fermentation tank can be used to characterize the state of the process. In this work, an experimental study of the density and ultrasonic velocity in the ternary mixture (water-ethanol-saccharose) is presented. Experimental results were compared to ideal density and to commonly used expressions of the sound velocity in liquid mixtures (Urick, Natta-Baccaredda and Nomoto). A semiempirical approach was proposed to improve the efficiency of theoretical models when dealing with mixtures of associated liquids. PMID:15567201

  6. Purification and Characterization of Sucrose Synthetase from the Shoot of Bamboo Leleba oldhami.

    PubMed

    Su, J C

    1977-07-01

    A 108-fold purification of the sucrose synthetase from the extract of the shoot of bamboo Lelaba oldhami was achieved by ammonium sulfate fractionation, calcium phosphate gel adsorption, and chromatographic separations on Sephadex G-100 and diethylaminoethyl-cellulose columns. Some properties of this enzyme, namely thermal and pH stabilities, stabilization by aqueous glycerol, pH optimum, substrate specificities, effects of metallic ions, effects of sulfhydryl reagents, molecular weight, sedimentation constants, isoelectric point, and substrate saturation kinetics had been investigated.The substrate saturation kinetics indicated that the enzyme could be an allosteric enzyme with the saccharide substrates (sucrose and fructose) serving as the homotropic allosteric effectors in regulating the biosynthesis and degradation of sucrose. PMID:16660030

  7. Aqueous Extract of Annona macroprophyllata: A Potential ?-Glucosidase Inhibitor

    PubMed Central

    Brindis, F.; González-Trujano, M. E.; González-Andrade, M.; Aguirre-Hernández, E.; Villalobos-Molina, R.

    2013-01-01

    Annona genus contains plants used in folk medicine for the treatment of diabetes. In the present study, an aqueous extract prepared from Annona macroprophyllata (Annonaceae, also known as A. diversifolia) leaves was evaluated on both the activity of yeast ?-glucosidase (an in vitro assay) and sucrose tolerance in Wistar rats. The results have shown that the aqueous extract from A. macroprophyllata inhibits the yeast ?-glucosidase with an IC50?=?1.18?mg/mL, in a competitive manner with a Ki = 0.97?mg/mL, a similar value to that of acarbose (Ki = 0.79?mg/mL). The inhibitory activity of A. macroprophyllata was reinforced by its antihyperglycemic effect, at doses of 100, 300, and 500?mg/kg in rats. Chromatographic analysis identified the flavonoids rutin and isoquercitrin in the most polar fractions of A. macroprophyllata crude extract, suggesting that these flavonoids are part of the active constituents in the plant. Our results support the use of A. macroprophyllata in Mexican folk medicine to control postprandial glycemia in people with diabetes mellitus, involving active constituents of flavonoid nature. PMID:24298552

  8. Glass transition and water effects on sucrose inversion by invertase in a lactose-sucrose system.

    PubMed

    Kouassi, K; Roos, Y H

    2000-06-01

    Enzymatic changes are often detrimental to quality of low-moisture foods. In the present study, effects of glass transition and water on sucrose inversion in a lactose-sucrose food model were investigated. Amorphous samples were produced by freeze-drying lactose-sucrose (2:1)-invertase (20 mg invertase/49.4 g of carbohydrate) dissolved in distilled water. Sorption isotherms were determined gravimetrically at 24 degrees C. Sucrose hydrolysis was determined by monitoring glucose content using a test kit and the amounts of fructose, glucose, and sucrose using HPLC. The glass transition temperatures, T(g), at various water contents were measured using differential scanning calorimetry (DSC). The BET and the GAB sorption models were fitted to experimental data up to a(w) 0.444 and 0.538, respectively. Water sorption and DSC results suggested time-dependent crystallization of sugars at a(w) 0.444 and above. Significant sucrose hydrolysis occurred only above T(g), concomitantly with crystallization. Sucrose hydrolysis and crystallization were not likely in glassy materials. PMID:10888568

  9. The sim Operon Facilitates the Transport and Metabolism of Sucrose Isomers in Lactobacillus casei ATCC 334?

    PubMed Central

    Thompson, John; Jakubovics, Nicholas; Abraham, Bindu; Hess, Sonja; Pikis, Andreas

    2008-01-01

    Inspection of the genome sequence of Lactobacillus casei ATCC 334 revealed two operons that might dissimilate the five isomers of sucrose. To test this hypothesis, cells of L. casei ATCC 334 were grown in a defined medium supplemented with various sugars, including each of the five isomeric disaccharides. Extracts prepared from cells grown on the sucrose isomers contained high levels of two polypeptides with Mrs of ?50,000 and ?17,500. Neither protein was present in cells grown on glucose, maltose or sucrose. Proteomic, enzymatic, and Western blot analyses identified the ?50-kDa protein as an NAD+- and metal ion-dependent phospho-?-glucosidase. The oligomeric enzyme was purified, and a catalytic mechanism is proposed. The smaller polypeptide represented an EIIA component of the phosphoenolpyruvate-dependent sugar phosphotransferase system. Phospho-?-glucosidase and EIIA are encoded by genes at the LSEI_0369 (simA) and LSEI_0374 (simF) loci, respectively, in a block of seven genes comprising the sucrose isomer metabolism (sim) operon. Northern blot analyses provided evidence that three mRNA transcripts were up-regulated during logarithmic growth of L. casei ATCC 334 on sucrose isomers. Internal simA and simF gene probes hybridized to ?1.5- and ?1.3-kb transcripts, respectively. A 6.8-kb mRNA transcript was detected by both probes, which was indicative of cotranscription of the entire sim operon. PMID:18310337

  10. Sucrose-induced vacuolation results in increased expression of cholesterol biosynthesis and lysosomal genes.

    PubMed

    Helip-Wooley, Amanda; Thoene, Jess G

    2004-01-01

    Mammalian cells cultured in the presence of high concentrations of sucrose demonstrate large, phase-lucent, osmotically swollen vacuoles. Three normal human fibroblast cell lines exposed to 100 mM of sucrose for 24 h demonstrated increased expression of lysosomal, intracellular vesicle trafficking, cholesterol biosynthesis, and fatty acid metabolism genes. Most steps of the cholesterol biosynthesis pathway were upregulated including HMG CoA reductase, which catalyzes the rate-limiting step of cholesterol biosynthesis. The lysosomal genes neuraminidase, CLN3, and CLCN5 and the small GTP-binding proteins Rab7L1 and Arl7 were also increased. A Rab7L1-GFP fusion protein was overexpressed in human fibroblasts and was demonstrated to localize primarily to the Golgi apparatus, and in some cells to the membranes bounding vesicles in the perinuclear region. Increased levels of the transcription factor C/EBP were found in nuclear extracts from cells exposed to sucrose for 12 h, relative to matched controls suggesting regulation of gene expression following sucrose-induced vacuolation may be coordinated, at least in part, by the transcription factor C/EBP. Sucrose-induced vacuolation is a useful model in which to study the regulation of lysosomal gene expression and biogenesis. PMID:14720509

  11. Modulation of Intestinal Inflammation by Yeasts and Cell Wall Extracts: Strain Dependence and Unexpected Anti-Inflammatory Role of Glucan Fractions

    PubMed Central

    Jawhara, Samir; Habib, Khalid; Maggiotto, François; Pignede, Georges; Vandekerckove, Pascal; Maes, Emmanuel; Dubuquoy, Laurent; Fontaine, Thierry; Guerardel, Yann; Poulain, Daniel

    2012-01-01

    Yeasts and their glycan components can have a beneficial or adverse effect on intestinal inflammation. Previous research has shown that the presence of Saccharomyces cerevisiae var. boulardii (Sb) reduces intestinal inflammation and colonization by Candida albicans. The aim of this study was to identify dietary yeasts, which have comparable effects to the anti-C. albicans and anti-inflammatory properties of Sb and to assess the capabilities of yeast cell wall components to modulate intestinal inflammation. Mice received a single oral challenge of C. albicans and were then given 1.5% dextran-sulphate-sodium (DSS) for 2 weeks followed by a 3-day restitution period. S. cerevisiae strains (Sb, Sc1 to Sc4), as well as mannoprotein (MP) and ?-glucan crude fractions prepared from Sc2 and highly purified ?-glucans prepared from C. albicans were used in this curative model, starting 3 days after C. albicans challenge. Mice were assessed for the clinical, histological and inflammatory responses related to DSS administration. Strain Sc1-1 gave the same level of protection against C. albicans as Sb when assessed by mortality, clinical scores, colonization levels, reduction of TNF? and increase in IL-10 transcription. When Sc1-1 was compared with the other S. cerevisiae strains, the preparation process had a strong influence on biological activity. Interestingly, some S. cerevisiae strains dramatically increased mortality and clinical scores. Strain Sc4 and MP fraction favoured C. albicans colonization and inflammation, whereas ?-glucan fraction was protective against both. Surprisingly, purified ?-glucans from C. albicans had the same protective effect. Thus, some yeasts appear to be strong modulators of intestinal inflammation. These effects are dependent on the strain, species, preparation process and cell wall fraction. It was striking that ?-glucan fractions or pure ?-glucans from C. albicans displayed the most potent anti-inflammatory effect in the DSS model. PMID:22848391

  12. Optimisation of ultrasound-assisted extraction conditions for maximal recovery of active monacolins and removal of toxic citrinin from red yeast rice by a full factorial design coupled with response surface methodology.

    PubMed

    Zhou, Guisheng; Fu, Lei; Li, Xiaobo

    2015-03-01

    This study optimised the ultrasound-assisted extraction (UAE) conditions to achieve maximal recovery of active monacolins with minimal contents of citrinin from red yeast rice (RYR). A central composite design after a full factorial design was utilised to examine the different UAE parameters. The studies revealed that HAc%, extraction time and EtOH% had significant influences on the recovery yield of monacolins, while HAc% and EtOH% were key factors for the elimination of citrinin. The resulting optimal conditions were as follows: ultrasound power of 250 W, HAc% of 7.7%, RYR amount of 0.2 g (solvent-to-solid ratio 40 mL/g), extraction time of 50.7 min, EtOH% of 57.2% and extraction temperature of 20 °C. Under these conditions, at least 94.7% of monacolins was recovered and 87.7% of citrinin was removed from RYR. This optimised UAE condition was further evaluated for potential industrial application in manufacturing of RYR as pharmaceuticals and nutraceuticals. PMID:25306334

  13. Dental caries: Possible sugar substitutes for sucrose

    Microsoft Academic Search

    Charlotte M. Thompson; Kaye Funk; Rachel Schemmel; Olaf Mickelsen

    1974-01-01

    This study investigated the use of sucrose, fructose, glucose, high fructose corn syrup (HFCS)§, and equal weights of fructose and glucose in cakes containing fat and prepared by the solution method of mixing. Cakes prepared with glucose scored lowest in all sensory attributes.According to objective measurements of product quality, cakes made with monosaccharides were smaller, more easily broken and more

  14. Enthalpy relaxation of freeze concentrated sucrose-water glass.

    PubMed

    Inoue, Chiharu; Suzuki, Toru

    2006-02-01

    The enthalpy relaxation of freeze concentrated sucrose-water glass was investigated using 40% sucrose, differential scanning calorimetry (DSC) with isothermal ageing for 1-6 days at various temperatures (-70, -65, -60, and -55 degrees C). The enthalpy relaxation was observed as an endothermic peak superimposed on the endothermic step-wise change due to the glass transition around -47 degrees C. The enthalpy relaxation was found to increase with ageing time and temperature. An 80% sucrose glass was also investigated at ageing temperatures of -60 and -65 degrees C, and this material exhibited a similar glass transition and enthalpy relaxation to that observed with the frozen 40% sucrose solution. The calculated activation energy of the enthalpy relaxation of the sucrose-water glass was smaller than that reported for pure sucrose. These results suggest that the freeze concentrated sucrose-water glass could have a higher molecular mobility and less stability than pure sucrose glass. PMID:16321366

  15. Sucrose accumulation in sugarcane: a potential target for crop improvement

    Microsoft Academic Search

    Monica Sachdeva; Surekha Bhatia; Suresh K. Batta

    Sugarcane is a highly productive crop plant with the capacity of storing large amounts of sucrose. Sucrose accumulation in\\u000a the stem of sugarcane has been studied extensively. The initial recognition and characterization of the enzymes involved in\\u000a sucrose synthesis and cleavage led to the widely accepted models of how sucrose accumulation occurs in the storage tissue.\\u000a New insights were gained

  16. FORMATION OF AUXIN IN YEAST CULTURES

    PubMed Central

    Robinson, True W.; Stier, T. J. B.

    1941-01-01

    We have found far more auxin in the culture media of bakers' yeast than was obtained by Kögl and Kostermans from the cells themselves. The production of auxin by yeast cells resembles the formation observed in other organisms such as Rhizopus and Rhizobium which also form auxins in their culture media. The auxin yield was found to increase with the concentration of sucrose and to decrease with the concentration of peptone. An inverse relation with the rate of cell multiplication was observed. Enlarged and elongated cells appeared only in those media which contained considerable amounts of auxin. The total auxin yield in the various cultures was found to be directly proportional, below pH 5, to the hydrogen ion concentration. Thus, it was proposed that certain growth conditions favor the breakage of the link between auxin and its protein carrier (Skoog and Thimann) 1940) and consequently accelerate the rate of excretion of auxin into the growth medium. PMID:19873251

  17. Sucrose Phosphate Synthase, Sucrose Synthase, and Invertase Activities in Developing Fruit of Lycopersicon esculentum Mill. and the Sucrose Accumulating Lycopersicon hirsutum Humb. and Bonpl. 1

    PubMed Central

    Miron, Daphne; Schaffer, Arthur A.

    1991-01-01

    The green-fruited Lycopersicon hirsutum Humb. and Bonpl. accumulated sucrose to concentrations of about 118 micromoles per gram fresh weight during the final stages of development. In comparison, Lycopersicon esculentum Mill. cultivars contained less than 15 micromoles per gram fresh weight of sucrose at the ripe stage. Glucose and fructose levels remained relatively constant throughout development in L. hirsutum at 22 to 50 micromoles per gram fresh weight each. Starch content was low even at early stages of development, and declined further with development. Soluble acid invertase (EC 3.2. 1.26) activity declined concomitant with the rise in sucrose content. Acid invertase activity, which was solubilized in 1 molar NaCl (presumably cell-wall bound), remained constant throughout development (about 3 micromoles of reducing sugars (per gram fresh weight) per hour. Sucrose phosphate synthase (EC 2.4.1.14) activity was present at about 5 micromoles of sucrose (per gram fresh weight) per hour even at early stages of development, and increased sharply to about 40 micromoles of sucrose (per gram fresh weight) per hour at the final stages of development studied, parallel to the rise in sucrose content. In comparison, sucrose phosphate synthase activity in L. esculentum remained low throughout development. The possible roles of the sucrose metabolizing enzymes in determining sucrose accumulation are discussed. PMID:16668028

  18. Sucrose Synthase, Starch Accumulation, and Tomato Fruit Sink Strength.

    PubMed Central

    Wang, F.; Sanz, A.; Brenner, M. L.; Smith, A.

    1993-01-01

    Contrasting evidence has accumulated regarding the role of acid invertase and sucrose synthase in tomato fruit sink establishment and maintenance. In this work the relationships among the activities of sucrose synthase and acid invertase, Lycopersicon esculentum Mill cv UC-82B fruit growth, and starch accumulation were analyzed in fruit at 0 to 39 d after anthesis. Sucrose synthase, but not acid invertase, was found to be positively correlated with tomato fruit relative growth rate and with starch content in the pericarp tissue. A similar association between sucrose synthase activity and starch accumulation was also evident in the basal portion of the stem. Heat-shock treatments, which inhibited the increase in sucrose synthase activity at the beginning of the light period and had no effect on acid invertase activity, were used to examine the importance of sucrose synthase in relation to sucrose metabolism and starch synthesis. After the heat-shock treatment, concomitantly with the suppressed sucrose synthase activity relative to the controls, there was a reduction in sucrose cleavage and starch accumulation. These data substantiate the conclusion that, during the early phases of tomato fruit development, sucrose synthase rather than acid invertase is the dominant enzyme in metabolizing imported sucrose, which in turn plays a part in regulating the import of sucrose into the fruit. PMID:12231688

  19. 21 CFR 172.859 - Sucrose fatty acid esters.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2009-04-01 true Sucrose fatty acid esters. 172.859 Section 172.859 Food and...Multipurpose Additives § 172.859 Sucrose fatty acid esters. Sucrose fatty acid esters identified in this section may be...

  20. 21 CFR 172.859 - Sucrose fatty acid esters.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Sucrose fatty acid esters. 172.859 Section 172.859 Food and...Multipurpose Additives § 172.859 Sucrose fatty acid esters. Sucrose fatty acid esters identified in this section may be...

  1. Sugar, water and free volume networks in concentrated sucrose solutions

    E-print Network

    Goddard III, William A.

    Sugar, water and free volume networks in concentrated sucrose solutions Valeria Molinero, Tahir the sucrose hydrogen bond network (HBN) in amorphous sucrose with 0­50% w/w water. We find that the onset) in these mixtures shows a non-monotonic behavior with water content which is consistent with experimental

  2. COMPARISON OF SUCROSE CATABOLISM IN ROOTS OF THREE BETA VULGARIS L. GENOTYPES WITH DIFFERENT YIELD AND SUCROSE ACCUMULATING CAPACITIES.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sucrose catabolism is a major determinant of sink strength in nearly all plants and affects sucrose partitioning to growing sinks as well as sink size and carbohydrate content. Three enzyme families are responsible for nearly all sucrose catabolism in sugarbeet roots: acid invertase, alkaline inve...

  3. Functional characterization of sucrose phosphorylase and scrR, a regulator of sucrose metabolism in Lactobacillus reuteri.

    PubMed

    Teixeira, Januana S; Abdi, Reihaneh; Su, Marcia Shu-Wei; Schwab, Clarissa; Gänzle, Michael G

    2013-12-01

    Lactobacillus reuteri harbours alternative enzymes for sucrose metabolism, sucrose phosphorylase, fructansucrases, and glucansucrases. Sucrose phosphorylase and fructansucrases additionally contribute to raffinose metabolism. Glucansucrases and fructansucrases produce exopolysaccharides as alternative to sucrose hydrolysis. L. reuteri LTH5448 expresses a levansucrase (ftfA) and sucrose phosphorylase (scrP), both are inducible by sucrose. This study determined the contribution of scrP to sucrose and raffinose metabolism in L. reuteri LTH5448, and elucidated the role of scrR in regulation sucrose metabolism. Disruption of scrP and scrR was achieved by double crossover mutagenesis. L. reuteri LTH5448, LTH5448?scrP and LTH5448?scrR were characterized with respect to growth and metabolite formation with glucose, sucrose, or raffinose as sole carbon source. Inactivation of scrR led to constitutive transcription of scrP and ftfA, demonstrating that scrR is negative regulator. L. reuteri LTH5448 and the LTH5448?scrP or LTH5448?scrR mutant strains did not differ with respect to glucose, sucrose or raffinose utilization. However, L. reuteri LTH5448?scrP produced more levan, indicating that the lack of sucrose phosphorylase is compensated by an increased metabolic flux through levansucrase. In conclusion, the presence of alternate pathways for sucrose and raffinose metabolism and their regulation indicate that these substrates, which are abundant in plants, are preferred carbohydrate sources for L. reuteri. PMID:24010626

  4. YEAST GENETICS Fred Winston

    E-print Network

    Winston, Fred

    YEAST GENETICS Fred Winston 7.1 Introduction Key Concepts · Genetic studies of the yeast. The yeast Saccharomyces cerevisiae is an ideal experimental organism. It is a microorganism that has a fast biology. Yeast has been the focus of extensive studies in many aspects of molecular biology. These areas

  5. Genital Yeast Infections

    Microsoft Academic Search

    J. D. Oriel; Betty M. Partridge; Maire J. Denny; J. C. Coleman

    1972-01-01

    Genital yeast infection was studied in 533 women seen in a department of venereology. Yeasts were recovered in culture from 138 patients (26% of the total). Candida albicans accounted for 112 (81%) of the isolates and Torulopsis glabrata for 22 (16%); other yeasts were uncommon. There was no evidence that the presence of yeasts was related to age. 32% of

  6. Assessment of Extracts from Red Yeast Rice for Herb-Drug Interaction by in-vitro and in-vivo assays

    PubMed Central

    Fung, Wai To; Subramaniam, G.; Lee, Joel; Loh, Heng Meng; Leung, Pak Ho Henry

    2012-01-01

    Red yeast rice (RYR) is made by fermenting the yeast Monascus purpureus over rice. It is a source of natural red food colorants, a food garnish and a traditional medication. Results of the current study demonstrated that polar fractions of the RYR preparations contained herbal-drug interaction activity, which if left unremoved, enhanced P-glycoprotein activity and inhibited the major drug metabolizing cytochromes P450, i,e, CYP 1A2, 2C9 and 3A4. The data from Caco-2 cell absorption and animal model studies further demonstrated that the pharmacokinetic modulation effect by RYR preparations containing the polar fractions (“untreated” preparation) was greater than that from RYR preparations with the polar fractions removed (“treated” preparation). The data indicates a potential for herb-drug interactions to be present in RYR commonly sold as nutritional supplements when the polar fractions are not removed and this should be taken into consideration when RYR is consumed with medications, including verapamil. PMID:22389767

  7. Possible Control of Maize Leaf Sucrose-Phosphate Synthase Activity by Light Modulation

    PubMed Central

    Sicher, Richard C.; Kremer, Diane F.

    1985-01-01

    Sucrose phosphate synthase (SPS) activity was measured in extracts of maize (Zea mays L.) and soybean (Glycine max L. [Merr.]) leaves over a single day/night cycle. There was a 2- to 3-fold postillumination increase in extractable enzyme activity in maize leaves, whereas the activity of soybean SPS was only about 30% higher in extracts prepared from light- compared to dark-adapted leaves. Alterations in extractable maize leaf SPS activity correlated with light/dark transitions suggesting that the enzyme may be light modulated. Diurnal variations of extractable maize leaf SPS activity were also observed in a greenhouse experiment. A transition from high (light) to low (dark) extractable SPS activity occurred near the light compensation point for photosynthesis (about 20 micromole photons per square meter per second). Further increases in irradiance did not increase extractable SPS activity. Substrate affinities for uridine 5?-diphosphoglucose (Michaelis constant = 3.5 and 5.1 millimolar) and fructose-6 phosphate (half maximal concentration = 1.0 and 2.5 millimolar) were lower for partially purified SPS obtained from light compared to dark acclimated maize leaves. Light-induced changes in extractable SPS activity were stable for at least one column chromatography step. The above results indicate that light-induced changes in SPS activity may be important in controlling the photosynthetic production of sucrose. PMID:16664475

  8. Prenatal ethanol increases sucrose reinforcement, an effect strengthened by postnatal association of ethanol and sucrose.

    PubMed

    Culleré, Marcela Elena; Spear, Norman E; Molina, Juan Carlos

    2014-02-01

    Late prenatal exposure to ethanol recruits sensory processing of the drug and of its motivational properties, an experience that leads to heightened ethanol affinity. Recent studies indicate common sensory and neurobiological substrates between this drug and sweet tastants. Using a recently developed operant conditioning technique for infant rats, we examined the effects of prenatal ethanol history upon sucrose self-administration (postnatal days, PDs 14-17). Prior to the last conditioning session, a low (0.5 g/kg) or a high (2.5 g/kg) ethanol dose were paired with sucrose. The intention was to determine if ethanol would inflate or devalue the reinforcing capability of the tastant and if these effects are dependent upon prenatal ethanol history. Male and female pups prenatally exposed to ethanol (2.0 g/kg) responded more when reinforced with sucrose than pups lacking this antenatal experience. Independently of prenatal status, a low ethanol dose (0.5 g/kg) enhanced the reinforcing capability of sucrose while the highest dose (2.5 g/kg) seemed to ameliorate the motivational properties of the tastant. During extinction (PD 18), two factors were critical in determining persistence of responding despite reinforcement omission. Pups prenatally exposed to ethanol that subsequently experienced the low ethanol dose paired with sucrose, showed higher resistance to extinction. The effects here reported were not associated with differential blood alcohol levels across prenatal treatments. These results indicate that fetal ethanol experience promotes affinity for a natural sweet reinforcer and that low doses of ethanol are also capable of enhancing the positive motivational consequences of sucrose when ethanol and sucrose are paired during infancy. PMID:24398347

  9. Stevia and sucrose effect on plaque formation

    Microsoft Academic Search

    Sonia Maria Blauth de Slavutzky

    2010-01-01

    An in vivo study was done by measuring the accumulation of dental plaque after rinsing with a solution of 10% sucrose four times daily\\u000a during 5 days and comparing it with a rinsing of 10% solution of Stevia rebaudiana Bertoni four times a day, during 5 days a week. The accumulation of dental plaque after rinsing with Stevia was 57, 82% less

  10. New phenylpropanoid esters of sucrose from Polygonum hydropiper and their antioxidant activity

    Microsoft Academic Search

    Phan Van Kiem; Nguyen Xuan Nhiem; Nguyen Xuan Cuong; Tran Quynh Hoa; Hoang Thanh Huong; Le Mai Huong; Chau Van Minh; Young Ho Kim

    2008-01-01

    By various chromatographic methods, two new phenylpropanoid esters of sucrose named hidropiperosides A (1) and B (2), and three known compounds as vanicosides A (3), B (4), and E (5) were isolated from the methanolic extract of the whole plant of Polygonum hydropiper L. (Polygonaceae). Their structures were elucidated by extensive spectroscopic methods including 1D-and 2D-NMR experiments,\\u000a as well as

  11. Identification of selenium-containing proteins in selenium-rich yeast aqueous extract by 2D gel electrophoresis, nanoHPLC-ICP MS and nanoHPLC-ESI MS/MS.

    PubMed

    Tastet, Laure; Schaumlöffel, Dirk; Bouyssiere, Brice; Lobinski, Ryszard

    2008-05-30

    An approach based on the consecutive use of nanoHPLC-ICP collision cell MS and nanoHPLC-electrospray MS was proposed for the analysis of water-soluble selenium-containing proteins in selenium-rich yeast after their separation by 2D gel electrophoresis (GE). An ultrasonic probe was employed for fast protein extraction avoiding sample heating and thus reducing the risk of protein degradation. The efficiency of different extraction steps were critically evaluated by total selenium analysis and size-exclusion chromatography (SEC)-ICP MS. Prior to electrophoresis proteins were purified by acetone precipitation. The protein-containing spots from 2D GE were excised and digested with trypsin. The digests obtained were analyzed by nanoHPLC-ICP MS in order to check for the presence of selenium-containing peptides; this allowed the detection of target proteins for further analyses (two out of five spots). The subsequent analyses of the selected digests by nanoHPLC-ES MS/MS allowed the attribution of amino acid sequences to peaks detected by ICP MS revealing the presence of two selenium-containing proteins: SIP 18 and HSP 12. PMID:18585195

  12. Kinetic model of sucrose accumulation in maturing sugarcane culm tissue.

    PubMed

    Uys, Lafras; Botha, Frederik C; Hofmeyr, Jan-Hendrik S; Rohwer, Johann M

    2007-01-01

    Biochemically, it is not completely understood why or how commercial varieties of sugarcane (Saccharum officinarum) are able to accumulate sucrose in high concentrations. Such concentrations are obtained despite the presence of sucrose synthesis/breakdown cycles (futile cycling) in the culm of the storage parenchyma. Given the complexity of the process, kinetic modelling may help to elucidate the factors governing sucrose accumulation or direct the design of experimental optimisation strategies. This paper describes the extension of an existing model of sucrose accumulation (Rohwer, J.M., Botha, F.C., 2001. Analysis of sucrose accumulation in the sugar cane culm on the basis of in vitro kinetic data. Biochem. J. 358, 437-445) to account for isoforms of sucrose synthase and fructokinase, carbon partitioning towards fibre formation, and the glycolytic enzymes phosphofructokinase (PFK), pyrophosphate-dependent PFK and aldolase. Moreover, by including data on the maximal activity of the enzymes as measured in different internodes, a growth model was constructed that describes the metabolic behaviour as sugarcane parenchymal tissue matures from internodes 3-10. While there was some discrepancy between modelled and experimentally determined steady-state sucrose concentrations in the cytoplasm, steady-state fluxes showed a better fit. The model supports a hypothesis of vacuolar sucrose accumulation against a concentration gradient. A detailed metabolic control analysis of sucrose synthase showed that each isoform has a unique control profile. Fructose uptake by the cell and sucrose uptake by the vacuole had a negative control on the futile cycling of sucrose and a positive control on sucrose accumulation, while the control profile for neutral invertase was reversed. When the activities of these three enzymes were changed from their reference values, the effects on futile cycling and sucrose accumulation were amplified. The model can be run online at the JWS Online database (http://jjj.biochem.sun.ac.za/database/uys). PMID:17555779

  13. Biosynthesis of Levan, a Bacterial Extracellular Polysaccharide, in the Yeast Saccharomyces cerevisiae

    PubMed Central

    Franken, Jaco; Brandt, Bianca A.; Tai, Siew L.; Bauer, Florian F.

    2013-01-01

    Levans are fructose polymers synthesized by a broad range of micro-organisms and a limited number of plant species as non-structural storage carbohydrates. In microbes, these polymers contribute to the formation of the extracellular polysaccharide (EPS) matrix and play a role in microbial biofilm formation. Levans belong to a larger group of commercially important polymers, referred to as fructans, which are used as a source of prebiotic fibre. For levan, specifically, this market remains untapped, since no viable production strategy has been established. Synthesis of levan is catalysed by a group of enzymes, referred to as levansucrases, using sucrose as substrate. Heterologous expression of levansucrases has been notoriously difficult to achieve in Saccharomyces cerevisiae. As a strategy, this study used an invertase (?suc2) null mutant and two separate, engineered, sucrose accumulating yeast strains as hosts for the expression of the levansucrase M1FT, previously cloned from Leuconostoc mesenteroides. Intracellular sucrose accumulation was achieved either by expression of a sucrose synthase (Susy) from potato or the spinach sucrose transporter (SUT). The data indicate that in both ?suc2 and the sucrose accumulating strains, the M1FT was able to catalyse fructose polymerisation. In the absence of the predicted M1FT secretion signal, intracellular levan accumulation was significantly enhanced for both sucrose accumulation strains, when grown on minimal media. Interestingly, co-expression of M1FT and SUT resulted in hyper-production and extracellular build-up of levan when grown in rich medium containing sucrose. This study presents the first report of levan production in S. cerevisiae and opens potential avenues for the production of levan using this well established industrial microbe. Furthermore, the work provides interesting perspectives when considering the heterologous expression of sugar polymerizing enzymes in yeast. PMID:24147008

  14. Cellulosic Ethanol Production from Xylose-extracted Corncob Residue by SSF Using Inhibitor- and Thermal-tolerant Yeast Clavispora NRRL Y-50339

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Xylose-extracted corncob residue, a byproduct of the xylose-producing industry using corncobs, is an abundant potential energy resource for cellulosic ethanol production. Simultaneous saccharification and fermentation (SSF) is considered an ideal one-step process for conversion of lignocellulosic b...

  15. Effect of salt on the response of birds to sucrose

    USGS Publications Warehouse

    Rogers, J.G., Jr.; Maller, O.

    1973-01-01

    The preference of male red-winged blackbirds for solutions of sucrose and sucrose with 0.03 M sodium chloride was tested, using a two-bottle choice test. Preliminary experiments demonstrated that the birds were indifferent to 0.03 M NaCl in water. Both control and experimental animals exhibited indifference to the solutions at the lowest concentration and aversion at the highest. The data suggest that the added sodium chloride makes the sucrose stimulus more discriminable.

  16. Yeast Education Network

    NSDL National Science Digital Library

    The Yeast Education Network provides a variety of resources to facilitate use of the budding yeast Saccharomyces cerevisiae in undergraduate science curricula. Laboratory, classroom, and computer-based activities can be used with college and advanced high school students.

  17. Vaginal Yeast Infections

    MedlinePLUS

    ... infection from your sexual partner. Condoms and dental dams may help prevent getting or passing yeast infections ... infection from your sexual partner. Condoms and dental dams may help prevent getting or passing yeast infections ...

  18. Vaginal Yeast Infection

    MedlinePLUS

    ... on. Read more information on enabling JavaScript. Vaginal Yeast Infection Skip Content Marketing Share this: Main Content Area Vaginal yeast infection, or vulvovaginal candidiasis, is a common cause ...

  19. Enzymatic synthesis of sucrose octaacetate using a novel alkaline protease.

    PubMed

    Li, Guiying; Cai, Yujie; Liao, Xiangru; Yin, Jing

    2011-03-01

    Acylation of 0.5 g sucrose with 1.2 ml acetic anhydride was carried out in 2 ml two-solvent medium of anhydrous pyridine/n-hexane (1:1, v/v) using 0.2 g crude protease from Serratia sp. Sucrose octaacetate was the sole product and more than 90% sucrose was converted in 24 h at 30°C. The purity of sucrose octaacetate reached 100%, via a simple purification method of alcohol/water washing and centrifugation. PMID:21072559

  20. Sucrose metabolism in halotolerant methanotroph Methylomicrobium alcaliphilum 20Z.

    PubMed

    But, Sergey Y; Khmelenina, Valentina N; Reshetnikov, Alexander S; Mustakhimov, Ildar I; Kalyuzhnaya, Marina G; Trotsenko, Yuri A

    2015-04-01

    Sucrose accumulation has been observed in some methylotrophic bacteria utilizing methane, methanol, or methylated amines as a carbon and energy source. In this work, we have investigated the biochemical pathways for sucrose metabolism in the model halotolerant methanotroph Methylomicrobium alcaliphilum 20Z. The genes encoding sucrose-phosphate synthase (Sps), sucrose-phosphate phosphatase (Spp), fructokinase (FruK), and amylosucrase (Ams) were co-transcribed and displayed similar expression levels. Functional Spp and Ams were purified after heterologous expression in Escherichia coli. Recombinant Spp exhibited high affinity for sucrose-6-phosphate and stayed active at very high levels of sucrose (K i  = 1.0 ± 0.6 M). The recombinant amylosucrase obeyed the classical Michaelis-Menten kinetics in the reactions of sucrose hydrolysis and transglycosylation. As a result, the complete metabolic network for sucrose biosynthesis and re-utilization in the non-phototrophic organism was reconstructed for the first time. Comparative genomic studies revealed analogous gene clusters in various Proteobacteria, thus indicating that the ability to produce and metabolize sucrose is widespread among prokaryotes. PMID:25577257

  1. CLONTECHInnovative Yeast Protocols Handbook

    E-print Network

    Erickson, F. Les

    CLONTECHInnovative Tools to Accelerate Discovery Yeast Protocols Handbook PT3024-1 (PR13103 FOR RESEARCH USE ONLY #12;Yeast Protocols Handbook CLONTECH Laboratories, Inc. www.clontech.com Protocol # PT3024-1 2 Version # PR13103 I. Introduction 4 II. Introduction to Yeast Promoters 5 III. Culturing

  2. Production of d-Mannitol and Glycerol by Yeasts

    PubMed Central

    Onishi, Hiroshi; Suzuki, Toshiyuki

    1968-01-01

    D-Mannitol has not so far been known as a major product of sugar metabolism by yeasts. Three yeast strains, a newly isolated yeast from soy-sauce mash, Torulopsis versatilis, and T. anomala, were found to be good mannitol producers. Under optimal conditions, the isolate produced mannitol at good yield of 30% of the sugar consumed. Glucose, fructose, mannose, galactose, maltose, glycerol, and xylitol were suitable substrates for mannitol formation. High concentrations of yeast extract, Casamino Acids, NaCl, and KCl in media affected significantly the mannitol yield, whereas high levels of inorganic phosphate did not show any detrimental effect. PMID:5749751

  3. Effects of sucrose and urea on soy hull pectic polysaccharide gel induced by D-glucono-1,5-lactone.

    PubMed

    Liu, He; Li, Qinghua; Zhu, Danshi; Li, Jun; Liu, Junshan; Geng, Ping; He, Yutang

    2013-10-15

    Gelation properties of pectic polysaccharide extracted with ammonium oxalate from soybean hulls assisted by microwave were seldom studied. Water mobility in soy hull pectic polysaccharide (SHPP) was firstly studied by low field NMR. D-Glucono-1,5-lactone (GDL) and sucrose both could decrease spin-spin relaxation times (T2) of SHPP solutions which indicated the SHPP network formed. Rheological analysis conformed that SHPP gel was formed induced by GDL and enhanced by sucrose. Urea can increase T2 and collapse the network of SHPP. TGA was used to draw the profiles of water desorption from SHPP solutions or gels, during heating at a controlled rate. It was found that sucrose increased the bound water content and urea acted a conversely role. Hydrogen bond is the main force to maintain SHPP gel network. PMID:23987379

  4. Media for preservative resistant yeasts: a collaborative study.

    PubMed

    Hocking, A D

    1996-04-01

    An international collaborative study was carried out to determine the most effective medium for selective isolation and enumeration of preservative resistant yeasts. Such a medium should prevent the growth of other yeasts such as Saccharomyces cerevisiae that are tolerant to lower levels of commonly used food preservatives, and sensitive yeasts such as Rhodotorula species. The study compared two non-selective media that are in common use for cultivation of yeasts from foods, Malt Extract agar (MEA) and Tryptone Glucose Yeast extract agar (TGY) with media made selective for preservative resistant yeasts by addition of 0.5% acetic acid to these two basal media (MEAA and TGYA). A fifth medium, Zygosaccharomyces bailii medium (ZBM) was also included in the study. These media were compared for their efficacy in selective isolation and enumeration of the preservative resistant yeasts Zygosaccharomyces bailii, Schizosaccharomyces pombe and Pichia membranaefaciens. MEA and TGY without acetic acid were used as control, non-selective media, and Rhodotorula glutinis was the preservative sensitive control culture. Seven laboratories in six countries took part in the study. Of the non-selective media, TGY generally gave the highest counts, and TGY amended with 0.5% acetic acid (TGYA) was the best medium for recovery of all three preservative-resistant yeasts. ZBM was found to be selective for Z. bailii, but counts of this yeast on ZBM were significantly lower than on TGYA. R. glutinis did not grow on any of the selective media. PMID:8796419

  5. Use of glutaraldehyde and benzalkonium chloride for minimizing post-harvest physio-chemical and microbial changes responsible for sucrose losses in sugar cane.

    PubMed

    Singh, Pushpa; Arya, Namita; Tiwari, Priyanka; Suman, Archna; Rai, R K; Shrivastava, A K; Solomon, S

    2008-08-27

    Sugar cane is sensitive to enormous sucrose losses induced by physio-chemical and microbial changes, the severity being increased during the time lag between harvest and crushing in the mills. Minimization of the sucrose losses in the field is essential for better sugar recovery and prevention of sucrose losses. An experiment was conducted to evaluate the efficacy of glutaraldehyde and benzalkonium chloride for their effects on the microbial counts and physio-chemical changes responsible for sucrose losses. Glutaraldehyde and benzalkonium chloride (1000 + 250 ppm) reduced the losses in sucrose content to 7.1% as compared to the 30.8% loss in the control, thus improving the performance by 76.9%. The application of chemicals reduced the acid invertase activity (by 60%), lowered weight loss, titrable acidity, reducing sugars content, dextran, ethanol, and ethylene production and respiration rates. The application led to the reduction in the total bacterial, fungal, Leuconostoc, and yeast counts by 67.92, 51.3%, 26.08, and 51.2%, respectively. PMID:18662009

  6. Isolation and characterization of ethanol tolerant yeast strains

    PubMed Central

    Tikka, Chiranjeevi; Osuru, Hari Prasad; Atluri, Navya; Raghavulu, Praveen Chakravarthi Veera; yellapu, Nanda Kumar; Mannur, Ismail Shaik; Prasad, Uppu Venkateswara; Aluru, Sudheer; K, Narasimha Varma; Bhaskar, Matcha

    2013-01-01

    Yeast strains are commonly associated with sugar rich environments. Various fruit samples were selected as source for isolating yeast cells. The isolated cultures were identified at Genus level by colony morphology, biochemical characteristics and cell morphological characters. An attempt has been made to check the viability of yeast cells under different concentrations of ethanol. Ethanol tolerance of each strain was studied by allowing the yeast to grow in liquid YEPD (Yeast Extract Peptone Dextrose) medium having different concentrations of ethanol. A total of fifteen yeast strains isolated from different samples were used for the study. Seven strains of Saccharomyces cerevisiae obtained from different fruit sources were screened for ethanol tolerance. The results obtained in this study show a range of tolerance levels between 7%-12% in all the stains. Further, the cluster analysis based on 22 RAPD (Random Amplified polymorphic DNA) bands revealed polymorphisms in these seven Saccharomyces strains. PMID:23750092

  7. Functionality of Inulin as a Sucrose Replacer in Cookie Baking

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Inulin was evaluated as a sucrose replacer for healthy cookie production with benefits of low glycemic impact and prebiotic soluble fiber. Sucrose (as a reference) and three inulin products of different concentrations (as soluble fibers) were used to explore the effects of sugar-replacer type on so...

  8. Sucrose Metabolism in Netted Muskmelon Fruit during Development

    PubMed Central

    Lingle, Sarah E.; Dunlap, James R.

    1987-01-01

    Sugar content and composition are major criteria used in judging the quality of netted muskmelon (Cucumis melo L. var reticulatus) fruit. Sugar composition and four enzymes of sucrose metabolism were determined in `Magnum 45' muskmelon fruit at 10-day intervals beginning 10 days after pollination (DAP) until full-slip (35 DAP). Sugar content increased in both outer (green) mesocarp and inner (orange) mesocarp between 20 and 30 DAP. The major proportion of total increase in sugar was attributed to sucrose accumulation. The large increase in sucrose relative to glucose and fructose was accompanied by a dramatic decrease in acid invertase activity, which was highest in both tissues at 10 and 20 DAP, and increases in sucrose phosphate synthase (SPS) and sucrose synthase activities. The green tissue had a lower proportion of total sugar as sucrose, greater invertase activity, and less SPS activity than the orange tissue. Changes in relative sucrose content were highly correlated with changes in enzyme activity. The results strongly suggest that increases in the proportion of sucrose found in melon fruit were associated with a decline in acid invertase activity and an increase in SPS activity approximately 10 days before full-slip. Therefore, these enzymes apparently play a key role in determining sugar composition and the quality of muskmelon fruit. PMID:16665448

  9. CHARACTERIZATION OF TWO SUCROSE SYNTHASE ISOFORMS IN SUGARBEET ROOT.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two sucrose synthase isoforms (ED 2.4.1.13) have been identified in developing sugarbeet (Beta vulgaris L.) roots. To aid in understanding the physiological significance of these multiple sucrose synthase isoforms, the two isoforms were partially purified and some of their physical and kinetic prop...

  10. Comparative Sucrose Responsiveness in Apis mellifera and A. cerana Foragers

    PubMed Central

    Yang, Wenchao; Kuang, Haiou; Wang, Shanshan; Wang, Jie; Liu, Wei; Wu, Zhenhong; Tian, Yuanyuan; Huang, Zachary Y.; Miao, Xiaoqing

    2013-01-01

    In the European honey bee, Apis mellifera, pollen foragers have a higher sucrose responsiveness than nectar foragers when tested using a proboscis extension response (PER) assay. In addition, Africanized honey bees have a higher sucrose responsiveness than European honey bees. Based on the biology of the Eastern honey bee, A. cerana, we hypothesized that A. cerana should also have a higher responsiveness to sucrose than A. mellifera. To test this hypothesis, we compared the sucrose thresholds of pollen foragers and nectar foragers in both A. cerana and A. mellifera in Fujian Province, China. Pollen foragers were more responsive to sucrose than nectar foragers in both species, consistent with previous studies. However, contrary to our hypothesis, A. mellifera was more responsive than A. cerana. We also demonstrated that this higher sucrose responsiveness in A. mellifera was not due to differences in the colony environment by co-fostering two species of bees in the same mixed-species colonies. Because A. mellifera foragers were more responsive to sucrose, we predicted that their nectar foragers should bring in less concentrated nectar compared to that of A. cerana. However, we found no differences between the two species. We conclude that A. cerana shows a different pattern in sucrose responsiveness from that of Africanized bees. There may be other mechanisms that enable A. cerana to perform well in areas with sparse nectar resources. PMID:24194958

  11. A high-performance liquid chromatography-based radiometric assay for sucrose-phosphate synthase and other UDP-glucose requiring enzymes

    SciTech Connect

    Salvucci, M.E.; Crafts-Brandner, S.J. (University of Kentucky, Lexington (USA))

    1991-05-01

    A method for product analysis that eliminates a problematic step in the radiometric sucrose-phosphate synthase assay is described. The method uses chromatography on a boronate-derivatized high-performance liquid chromatography column to separate the labeled product, (14C)sucrose phosphate, from unreacted uridine 5{prime}-diphosphate-(14C)glucose (UDP-Glc). Direct separation of these compounds eliminates the need for treatment of the reaction mixtures with alkaline phosphatase, thereby avoiding the problem of high background caused by contaminating phosphodiesterase activity in alkaline phosphatase preparations. The method presented in this paper can be applied to many UDP-Glc requiring enzymes; here the authors show its use for determining the activities of sucrose-phosphate synthase, sucrose synthase, and uridine diphosphate-glucose pyrophosphorylase in plant extracts.

  12. 77 FR 18827 - Draft Guidance for Industry on Bioequivalence Recommendations for Iron Sucrose Injection...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-28

    ...Industry on Bioequivalence Recommendations for Iron Sucrose Injection; Availability AGENCY...Bioequivalence Recommendations for Iron Sucrose.'' The recommendations provide...abbreviated new drug applications (ANDAs) for iron sucrose injection. DATES: Although...

  13. Nicotine increases sucrose self-administration and seeking in rats

    PubMed Central

    Grimm, Jeffrey W.; Ratliff, Christine; North, Kindsey; Barnes, Jesse; Collins, Stefan

    2012-01-01

    Associations between nicotine in cigarettes and food consumption may alter the incentive value of food such that food cue-reactivity is exaggerated during abstinence from smoking. This effect may contribute to the weight gain associated with cessation of smoking. We examined the effects of nicotine (0.4 mg/kg base SC) paired (NPD) or unpaired (NUP) with 10 % sucrose self-administration (0.2 ml/delivery, 1h/day for 10 days) on self-administration response rate and intake as well as sucrose cue-reactivity following either 1 or 30 days of forced abstinence. Rats were administered the training dose of nicotine prior to a second, consecutive cue-reactivity session. NPD rats responded at over 3 times the rate for sucrose, and earned nearly twice the number of sucrose deliveries, as NUP rats or saline controls. Sucrose cue-reactivity was greater after 30 days, vs. 1 day of forced abstinence for all groups. History of nicotine exposure had no effect on sucrose cue-reactivity. However, the subsequent injection of nicotine increased sucrose cue-reactivity only in the NPD groups. There were no abstinent-dependent effects of nicotine challenge on sucrose cue-reactivity. A study conducted in parallel with water as the reinforcer revealed a less dramatic effect of nicotine on intake. There was no history or abstinence-dependent effects of nicotine on water cue-reactivity. Nicotine increases the reinforcing effects of sucrose and sucrose-paired cues when nicotine is present. An implication of these findings is that relapse to nicotine (cigarettes) could substantially elevate food cue-reactivity. PMID:22340200

  14. Electrical stimulation of the energy metabolism in yeast cells using a planar Ti-Au-electrode interface.

    PubMed

    Reiher, A; Warnke, C; Radoch, S; Witte, H; Krtschil, A; Mair, T; Müller, S C; Krost, A

    2006-04-01

    We report on the influence of dielectric pulse injection on the energy metabolism of yeast cells with a planar interdigitated electrode interface. The energy metabolism was measured via NADH fluorescence. The application of dielectric pulses results in a distinct decrease of the fluorescence, indicating a response of the energy metabolism of the yeast cells. The reduction of the NADH signal significantly depends on the pulse parameters, i.e., amplitude and width. Furthermore, the interface is used to detect electrical changes in the cell-electrolyte system, arising from glucose-induced oscillations in yeast cells and yeast extract, by dielectric spectroscopy at 10 kHz. These dielectric investigations revealed a beta(1)-dispersion for the system electrolyte/yeast cells as well as for the system electrolyte/yeast extract. In agreement with control measurements we obtained a glycolytic period of 45 s for yeast cells and of 11 min for yeast extract. PMID:17031550

  15. Studies on sucrose-phosphate synthase from rice leaves.

    PubMed

    Salerno, G L; Pagnussat, G C; Pontis, H G

    1998-05-01

    Sucrose-phosphate synthase (SPS, EC 2.4.1.14) biochemical properties and peptide composition have been analyzed in rice leaf seedlings. SPS was purified using DEAE-Sephacel chromatography, gel filtration on Sepharose 6B and anion exchange chromatography on Mono Q. At this stage two enzyme forms (SPS-I and -II) were separated. SPS-II was purified 90-fold; however, SPS-I presented a lower specific activity regarding the previous purification step and an unstable activity. Both enzyme forms had similar apparent Km values for Fru-6P but the SPS-I Km for UDP-Glc was ca. 10-fold higher than the SPS-II one. In addition, they differentiate in the capacity of being modulated by Glc-6-P and Pi: while SPS-II activity was inhibited by Pi and activated by Glc-6-P, SPS-I was not affected by either effectors. A native molecular mass of ca. 420 kDa was found by gel filtration. In SPS expression analysis using leaf rice and wheat germ SPS antibodies, a 116 kDa polypeptide was revealed in rice leaf extracts and no polypeptide was immunoactive in rice roots. PMID:9620436

  16. Aspen SUCROSE TRANSPORTER3 allocates carbon into wood fibers.

    PubMed

    Mahboubi, Amir; Ratke, Christine; Gorzsás, András; Kumar, Manoj; Mellerowicz, Ewa J; Niittylä, Totte

    2013-12-01

    Wood formation in trees requires carbon import from the photosynthetic tissues. In several tree species, including Populus species, the majority of this carbon is derived from sucrose (Suc) transported in the phloem. The mechanism of radial Suc transport from phloem to developing wood is not well understood. We investigated the role of active Suc transport during secondary cell wall formation in hybrid aspen (Populus tremula × Populus tremuloides). We show that RNA interference-mediated reduction of PttSUT3 (for Suc/H(+) symporter) during secondary cell wall formation in developing wood caused thinner wood fiber walls accompanied by a reduction in cellulose and an increase in lignin. Suc content in the phloem and developing wood was not significantly changed. However, after (13)CO2 assimilation, the SUT3RNAi lines contained more (13)C than the wild type in the Suc-containing extract of developing wood. Hence, Suc was transported into developing wood, but the Suc-derived carbon was not efficiently incorporated to wood fiber walls. A yellow fluorescent protein:PttSUT3 fusion localized to plasma membrane, suggesting that reduced Suc import into developing wood fibers was the cause of the observed cell wall phenotype. The results show the importance of active Suc transport for wood formation in a symplasmically phloem-loading tree species and identify PttSUT3 as a principal transporter for carbon delivery into secondary cell wall-forming wood fibers. PMID:24170204

  17. The sucrose–trehalose 6-phosphate (Tre6P) nexus: specificity and mechanisms of sucrose signalling by Tre6P

    PubMed Central

    Yadav, Umesh Prasad; Ivakov, Alexander; Feil, Regina; Lunn, John Edward

    2014-01-01

    Trehalose 6-phosphate (Tre6P), the intermediate of trehalose biosynthesis, has a profound influence on plant metabolism, growth, and development. It has been proposed that Tre6P acts as a signal of sugar availability and is possibly specific for sucrose status. Short-term sugar-feeding experiments were carried out with carbon-starved Arabidopsis thaliana seedlings grown in axenic shaking liquid cultures. Tre6P increased when seedlings were exogenously supplied with sucrose, or with hexoses that can be metabolized to sucrose, such as glucose and fructose. Conditional correlation analysis and inhibitor experiments indicated that the hexose-induced increase in Tre6P was an indirect response dependent on conversion of the hexose sugars to sucrose. Tre6P content was affected by changes in nitrogen status, but this response was also attributable to parallel changes in sucrose. The sucrose-induced rise in Tre6P was unaffected by cordycepin but almost completely blocked by cycloheximide, indicating that de novo protein synthesis is necessary for the response. There was a strong correlation between Tre6P and sucrose even in lines that constitutively express heterologous trehalose-phosphate synthase or trehalose-phosphate phosphatase, although the Tre6P:sucrose ratio was shifted higher or lower, respectively. It is proposed that the Tre6P:sucrose ratio is a critical parameter for the plant and forms part of a homeostatic mechanism to maintain sucrose levels within a range that is appropriate for the cell type and developmental stage of the plant. PMID:24420566

  18. Formulation with ascorbic acid and sucrose modulates catechin bioavailability from green tea

    PubMed Central

    Peters, Catrina M.; Green, Rodney J.; Janle, Elsa M.; Ferruzzi, Mario G.

    2009-01-01

    In order to investigate the impact of common food ingredients on catechin absorption, green tea (GT) extract (50 mg) was formulated plain, with sucrose (GT+S), with ascorbic acid (GT+AA) and with sucrose and ascorbic acid (GT+S+AA). Bioavailability and bioaccessibility were assessed in Sprague Dawley rats and an in vitro digestion/Caco-2 cell model respectively. Absorption of epigallocatechin (EGC) and epigallocatechin gallate (EGCG) was significantly (P<0.05) enhanced in GT+S+AA formulations (AUC0-6h= 3237.0 and 181.8 pmol*h/L plasma respectively) relative to GT control (AUC0-6h = 1304.1 and 61.0 pmol*h/L plasma respectively). In vitro digestive recovery was higher for EGC and epicatechin (EC) (?51-53%) relative to EGCG and epicatechin gallate (ECG) (< 20%) and was modestly enhanced in GT+S and GT+S+AA formulations. Accumulation of EGC, EGCG and ECG by Caco-2 cells was significantly (P<0.05) higher from GT+S+AA compared to other formulations while retention of catechins was enhanced in presence of ascorbic acid. These data suggest that formulation with sucrose and ascorbic acid may improve catechin bioavailability by enhancing bioaccessibility and intestinal uptake from tea. PMID:20161530

  19. Sucrose esters from Physalis peruviana calyces with anti-inflammatory activity.

    PubMed

    Franco, Luis A; Ocampo, Yanet C; Gómez, Harold A; De la Puerta, Rocío; Espartero, José L; Ospina, Luis F

    2014-11-01

    Physalis peruviana is a native plant from the South American Andes and is widely used in traditional Colombian medicine of as an anti-inflammatory medicinal plant, specifically the leaves, calyces, and small stems in poultice form. Previous studies performed by our group on P. peruviana calyces showed potent anti-inflammatory activity in an enriched fraction obtained from an ether total extract. The objective of the present study was to obtain and elucidate the active compounds from this fraction and evaluate their anti-inflammatory activity in vivo and in vitro. The enriched fraction of P. peruviana was purified by several chromatographic methods to obtain an inseparable mixture of two new sucrose esters named peruviose A (1) and peruviose B (2). Structures of the new compounds were elucidated using spectroscopic methods and chemical transformations. The anti-inflammatory activity of the peruvioses mixture was evaluated using ?-carrageenan-induced paw edema in rats and lipopolysaccharide-activated peritoneal macrophages. Results showed that the peruvioses did not produce side effects on the liver and kidneys and significantly attenuated the inflammation induced by ?-carrageenan in a dosage-dependent manner, probably due to an inhibition of nitric oxide and prostaglandin E2, which was demonstrated in vitro. To our knowledge, this is the first report of the presence of sucrose esters in P. peruviana that showed a potent anti-inflammatory effect. These results suggest the potential of sucrose esters from the Physalis genus as a novel natural alternative to treat inflammatory diseases. PMID:25338213

  20. Viscous properties of microparticulated dairy proteins and sucrose.

    PubMed

    Onwulata, C I; Konstance, R P; Tomasula, P M

    2002-07-01

    Slurries of whey protein concentrate (WPC) or sodium caseinate (Na-CN) mixed with sucrose (36% T.S.) were subjected to microparticulation by a high shear homogenizer operated at 27,000 rpm for 2, 4, and 6 min to facilitate gel formation. After microparticulation treatment, the milk protein and sucrose slurries were evaporated at 85 degrees C for 60 min under a partial vacuum (20 to 45 mm of Hg) to form composite gels. Particle sizes and viscoelastic properties were determined before microparticulation treatment. Microparticulation reduced the particle size of WPC-sucrose slurries from an average size of 330 to 188 nm after 4 min and NaCN-sucrose slurries from 270 to 35 nm after 2 min. The WPC-sucrose composites were gel-like, but NaCN-sucrose composites did not gel. Viscoelastic properties of heated WPC-sucrose composites were liquid-like, exhibiting significant reduction in storage modulus and complex viscosity. Microparticulation reduced particle sizes, which resulted in softer gels as time of shearing increased. PMID:12201517

  1. Transformation of Yeast

    Microsoft Academic Search

    Albert Hinnen; James B. Hicks; Gerald R. Fink

    1978-01-01

    A stable leu2- yeast strain has been transformed to LEU2+ by using a chimeric ColE1 plasmid carrying the yeast leu2 gene. We have used recently developed hybridization and restriction endonuclease mapping techniques to demonstrate directly the presence of the transforming DNA in the yeast genome and also to determine the arrangement of the sequences that were introduced. These studies show

  2. Vaginal Yeast Infections (For Parents)

    MedlinePLUS

    ... treatment is simple and painless. What Is a Yeast Infection? A yeast infection, also known as candidiasis ( ... you can be treated appropriately. Do Guys Get Yeast Infections? Guys can get an infection of the ...

  3. Red Yeast Rice: An Introduction

    MedlinePLUS

    ... links Read our disclaimer about external links Menu Red Yeast Rice: An Introduction On this page: Key ... will help ensure coordinated and safe care. About Red Yeast Rice Red yeast rice is made by ...

  4. Studies on methanol - oxidizing yeast. III. Enzyme.

    PubMed

    Volfová, O

    1975-01-01

    Oxidation of methanol, formaldehyde and formic acid was studied in cells and cell-free extract of the yeast Candida boidinii No. 11Bh. Methanol oxidase, an enzyme oxidizing methanol to formaldehyde, was formed inducibly after the addition of methanol to yeast cells. The oxidation of methanol by cell-free extract was dependent on the presence of oxygen and independent of any addition of nicotine-amide nucleotides. Temperature optimum for the oxidation of methanol to formaldehyde was 35 degrees C, pH optimum was 8.5. The Km for methanol was 0.8mM. The cell-free extract exhibited a broad substrate specificity towards primary alcohols (C1--C6). The activity of methanol oxidase was not inhibited by 1mM KCN, EDTA or monoiodoacetic acid. The strongest inhibitory action was exerted by p-chloromercuribenzoate. Both the cells and the cell-free extract contained catalase which participated in the oxidation of methanol to formaldehyde; the enzyme was constitutively formed by the yeast. The pH optimum for the degradation of H2O2 was in the same range as the optimum for methanol oxidation, viz. at 8.5. Catalase was more resistant to high pH than methanol oxidase. The cell-free extract contained also GSH-dependent NAD-formaldehyde dehydrogenase with Km = 0.29mM and NAD-formate dehydrogenase with Km = 55mM. PMID:240764

  5. Structural determinants of product specificity of sucrose isomerases.

    PubMed

    Ravaud, Stéphanie; Robert, Xavier; Watzlawick, Hildegard; Haser, Richard; Mattes, Ralf; Aghajari, Nushin

    2009-06-18

    The healthy sweetener isomaltulose is industrially produced from the conversion of sucrose by the sucrose isomerase SmuA from Protaminobacter rubrum. Crystal structures of SmuA in native and deoxynojirimycin complexed forms completed with modeling studies unravel the characteristics of the isomaltulose synthases catalytic pocket and their substrate binding mode. Comparison with the trehalulose synthase MutB highlights the role of Arg(298) and Arg(306) active site residues and surface charges in controlling product specificity of sucrose isomerases (isomaltulose versus trehalulose). The results provide a rationale for the specific design of optimized enzymes. PMID:19427862

  6. Regulation of Key Enzymes of Sucrose Biosynthesis in Soybean Leaves 1

    PubMed Central

    Cheikh, Nordine; Brenner, Mark L.

    1992-01-01

    An important part in the understanding of the regulation of carbon partitioning within the leaf is to investigate the endogenous variations of parameters related to carbon metabolism. This study of diurnal changes in the activities of sucrose-synthesizing enzymes and levels of nonstructural carbohydrates in intact leaves of field-grown soybean plants (Glycine max [L.]) showed pronounced diurnal fluctuations in sucrose phosphate synthase (SPS) activity. However, there was no distinct diurnal change in the activity of fructose-1,6-bisphosphatase (F1,6BPase). SPS activity in leaves from plants grown in controlled environments presented two peaks during the light period. In contrast to field-grown plants, F1,6BPase activity in leaves from growth chamber-grown plants manifested one peak during the first half of the light period. In plants grown under both conditions, sucrose and starch accumulation rates were highest during early hours of the light period. By the end of the dark period, most of the starch was depleted. A pattern of diurnal fluctuations of abscisic acid (ABA) levels in leaves was also observed under all growing conditions. Either imposition of water stress or exogenous applications of ABA inhibited F1,6BPase activity. However, SPS-extractable activity increased following water deficit but did not change in response to ABA treatment. Gibberellin application to intact soybean leaves increased levels of both starch and sucrose. Both gibberellic acid (10?6m) and gibberellins 4 and 7 (10?5m) increased the activity of SPS but had an inconsistent effect on F1,6BPase. Correlation studies between the activities of SPS and F1,6BPase suggest that these two enzymes are coordinated in their function, but the factors that regulate them may be distinct because they respond differently to certain environmental and physiological changes. PMID:16653110

  7. Cryptococcus friedmannii, a new species of yeast from the Antarctic

    NASA Technical Reports Server (NTRS)

    Vishniac, H. S.

    1985-01-01

    Cryptococcus friedmannii Vishniac sp. nov. from an Antarctic cryptoendolithic community is a psychrophilic basidioblastomycete characterized by cream-colored colonies of cells with smooth, layered walls, budding monopolarly, producing amylose and extracellular proteinase, utilizing nitrate and D-alanine (inter alia) as nitrogen sources and L-arabinose, arbutin, cellobiose, D-glucuronate, maltose, melezitose, salicin, soluble starch, trehalose, and D-xylose as carbon sources. This species differs from all other basidiomycetous yeasts in possessing the following combination of characters: amylose production (positive), assimilation of cellobiose (positive), D-galactose (negative), myo-inositol (negative), D-mannitol (negative), and sucrose (negative).

  8. A reassessment of the role of sucrose synthase in the hypoxic sucrose-ethanol transition in Arabidopsis.

    PubMed

    Santaniello, Antonietta; Loreti, Elena; Gonzali, Silvia; Novi, Giacomo; Perata, Pierdomenico

    2014-10-01

    Plants under low-oxygen availability adapt their metabolism to compensate for the lower ATP production that arises from the limited respiratory activity in mitochondria. Anaerobic glycolysis requires continuous fuelling of carbon units, also provided from sucrose. The anaerobic catabolism of sucrose is thought to require the activity of sucrose synthase, being this enzymatic reaction more energetically favourable than that of invertase. The role of sucrose synthases (SUS) for aerobic sucrose catabolism in Arabidopsis has been recently questioned since SUS mutants fail to show altered phenotype or metabolic profile. In the present paper, we analysed the role of SUS1 and SUS4, both induced by low oxygen, in plant survival and ethanol production. The results showed that mutants lacking both SUS were as tolerant to low oxygen as the wild type in most of the experimental conditions tested. Only under conditions of limiting sugar availability the requirement of SUS1 and SUS4 for ethanol production was evident, although partly compensated by invertase activities, as revealed by the use of a double mutant lacking the two major cytosolic invertases. We conclude that, contrary to general belief, the sucrose synthase pathway is not the preferential route for sucrose metabolism under hypoxia. PMID:24810896

  9. Abstinence-dependent transfer of lithium chloride-induced sucrose aversion to a sucrose-paired cue in rats

    PubMed Central

    Harkness, John H.; Webb, Sierra

    2010-01-01

    Rationale Responding for a drug- or sucrose-paired cue increases over forced abstinence (incubation of craving). If the incentive value of a cue depends on the incentive value of the primary reward, devaluing the primary reward should reduce cue reactivity. Objectives We investigated whether conditioned taste aversion (CTA) to sucrose would transfer to a sucrose-paired cue after 1 or 30 days of forced abstinence and whether CTA after 1 day of forced abstinence would affect incubation of craving. Materials and methods Rats self-administered 10% sucrose paired with a tone + light cue for 10 days. After 1 (Exp.1) or 30 (Exp.2) days of forced abstinence, rats received two home-cage pairings of sucrose with either LiCl (65 mg/kg, IP) to produce CTA or saline as a control. Two days later, rats responded for the cue alone. The following day, sucrose consumption was assessed in the same operant conditioning chamber. Exp.1 rats were tested again 1 month later to determine if CTA would affect incubation of craving. Results Exp.1: CTA after 1 day of forced abstinence did not attenuate cue reactivity when tested immediately after CTA, nor did the treatment affect incubation of craving or incubation of sucrose consumption. Exp.2: CTA after 1 month of forced abstinence resulted in a significant reduction in cue reactivity. Conclusion The incentive values of sucrose and the conditioned representation of sucrose increase over an extended period of forced abstinence. This incubation appears to facilitate the transfer of an aversion to the primary reward to the conditioned cue. PMID:20039021

  10. An Ontology-Empowered Model for Annotating Protein-Protein Interaction Data: a Case Study for Budding Yeast

    E-print Network

    Haarslev, Volker

    for Budding Yeast Arash Shaban-Nejad and Volker Haarslev Dept. Computer Science and Software Eng to support and improve data mining tasks of yeast protein interactions for knowledge discovery on our experience in extracting knowledge from current data and information sources of the yeast protein

  11. Production of extracellular and total invertase by Candida utilis, Saccharomyces cerevisiae, and other yeasts.

    PubMed

    DWORSCHACK, R G; WICKERHAM, L J

    1961-07-01

    Some strains of Candida utilis produce exceptionally large amounts of extracellular and total invertase. Strain Y-900 of C. utilis produces high yields whether the carbon source is sucrose, glucose, maltose, or xylose and still higher yields with lactic acid, glycerol, and ethyl alcohol. Approximately 20 to 30% of the total invertase of C. utilis is extracellular. Strains of Saccharomyces cerevisiae and Saccharomyces carlsbergensis are generally inferior to C. utilis in production of extracellular and total invertase, the difference being accentuated in shaken cultures. The industrial yeasts are generally superior in invertase production to the other yeasts included in the survey. PMID:13725351

  12. Pityrosporum yeasts--what's new?

    PubMed

    Faergemann, J

    1997-01-01

    The lipophilic yeast Pityrosporum ovale is a member of the normal human cutaneous flora in adults but also associated with several skin diseases. In pityriasis versicolor, under the influence of predisposing factors, P. ovale changes from the round blastospore form to the mycelial form. A great problem in pityriasis versicolor is the high rate of recurrence and to avoid this a prophylactic treatment is mandatory. Pityrosporum folliculitis is a chronic disease characterized by pruritic follicular papules and pustules located primarily on the upper trunk, neck and upper arms. In direct microscopy clusters of round budding yeast cells are found. The disease responds rapidly to antimycotic therapy. There are now many studies indicating that P. ovale plays an important role in seborrhoeic dermatitis. Many of these are treatment studies showing a good effect of antimycotics paralleled by a reduction in number of organisms. Severe seborrhoeic dermatitis often difficult to treat is associated with AIDS. In peripheral blood from a high number of patients with seborrhoeic dermatitis we found an increase in number of natural killer T-cells and decreased PHA and Con-A stimulation. Secondary we found low serum IgG antibody titres in patients compared to controls. Other studies have found a reduced lymphocyte stimulation reaction when lymphocytes from patients with seborrhoeic dermatitis were stimulated with a P. ovale extract. Additionally, IL-2 and IFN gamma production by lymphocytes from patients was markedly depressed and IL-10 synthesis were increased after stimulation with P. ovale extract. The majority of adult patients with atopic dermatitis localized to the head, neck and scalp are prick-test positive to a protein P. ovale extract. One study showed that p. ovale extracts increased IL-4, IL-10 and IgE synthesis in patients with atopic dermatitis. There are also treatment studies indicating that antifungal treatment may be beneficial in these patients. PMID:9370147

  13. Sucrose substitutes and their role in caries prevention.

    PubMed

    Matsukubo, Takashi; Takazoe, Ichiro

    2006-06-01

    Many non- or low-cariogenic sucrose substitutes are currently available and are found as ingredients of a variety of candy, chewing gum, and drinks. Recently the role of sugar alcohols in promoting remineralisation of enamel has attracted much attention. Thus, the dental profession needs to understand the general characteristics and features of sugar substitutes to provide advice on oral health to patients as well as the general public. There are two critical requirements for sucrose substitutes, namely, being nutritionally appropriate and not being detrimental to the overall general health of the individual. The use of a greater variety of confectionary containing sucrose substitutes and the development of new substitutes with high nutritional value are essential in the battle against caries. In this paper we review in detail the characteristics of sucrose substitutes currently in use, their role in caries prevention and promotion of oral health. PMID:16826877

  14. New sucrose esters from the fruits of Physalis solanaceus.

    PubMed

    Pérez-Castorena, Ana-Lidia; Luna, Minerva; Martínez, Mahinda; Maldonado, Emma

    2012-05-01

    Three new sucrose esters (1-3) along with several known compounds were isolated from the fruits of Physalis solanaceus. The structural elucidation of the isolates was based on their spectroscopic characteristics mainly those of MS and NMR. PMID:22402100

  15. Improved synthesis of sucrose fatty acid monoesters under ultrasonic irradiation.

    PubMed

    Huang, Dan; Jiang, Xue; Zhu, Hao; Fu, Xiaorong; Zhong, Kangrong; Gao, Weidong

    2010-02-01

    Sucrose fatty acid esters were synthesized by the transesterification of sucrose with aliphatic esters under ultrasound irradiation in good yield (73%). The optimum reaction conditions for the transesterification reaction include a molar ratio of sucrose to fatty acid ethyl ester of 2:1 and the use of a 13%mol anhydrous K(2)CO(3) catalyst. The optimum reaction temperature was set at 70 degrees C, the optimum reaction time was 2h, and the optimum reaction pressure was 11kPa. The reaction had excellent monoester selectivity. The proportion of monoester (6-monoester+6'-monoester) in the purified products was up to 92-95% via flash column chromatography over silica gel, the ratios of 6-monoester/6'-monoester are 2.1-2.7, and the sucrose monoesters were identified by HPLC-MS, NMR and IR. PMID:19819179

  16. Mitochondrial assembly in yeast

    Microsoft Academic Search

    Les A Grivell; Marta Artal-Sanz; Gertjan Hakkaart; Liesbeth de Jong; Leo G. J Nijtmans; Katinka van Oosterum; Michel Siep; Hans van der Spek

    1999-01-01

    The yeast Saccharomyces cerevisiae is likely to be the first organism for which a complete inventory of mitochondrial proteins and their functions can be drawn up. A survey of the 340 or so proteins currently known to be localised in yeast mitochondria reveals the considerable investment required to maintain the organelle’s own genetic system, which itself contributes seven key components

  17. Alcoholic Fermentation in Yeast

    NSDL National Science Digital Library

    Ingrid Waldron

    Students learn about the basics of aerobic cellular respiration and alcoholic fermentation and design and carry out experiments to test how variables such as sugar concentration influence the rate of alcoholic fermentation in yeast. In an optional extension activity students can use their yeast mixture to make a small roll of bread.

  18. Yeasts: Neglected Pathogens

    Microsoft Academic Search

    Daniel Poulain; Boualem Sendid; Annie Standaert-Vitse; Chantal Fradin; Thierry Jouault; Samir Jawhara; Jean-Frederic Colombel

    2009-01-01

    Background: Current research on Crohn’s disease (CD) concerns molecular events related to loss of tolerance to microbes that could trigger or maintain inflammation in genetically susceptible individuals. CD is also associated with antimicrobial antibodies, including the antibodies we described against yeast oligomannosides (ASCA). This prompted us to investigate a role for another yeast, Candida albicans, a very common commensal of

  19. Parabrachial coding of sapid sucrose: Relevance to reward and obesity

    PubMed Central

    Hajnal, Andras; Norgren, Ralph; Kovacs, Peter

    2013-01-01

    Cumulative evidence in rats suggests that the pontine parabrachial nucleus (PBN) is necessary for assigning hedonic value to taste stimuli. In a series of studies, our laboratory has investigated the parabrachial coding of sapid sucrose in normal and obese rats. First, using chronic microdialysis, we demonstrated that sucrose intake increases dopamine release in the nucleus accumbens, an effect that is dependent on oral stimulation and on concentration. The dopamine response was independent of the thalamocortical gustatory system, but was blunted substantially by lesions of the PBN. Similar lesions of the PBN but not the thalamic taste relay diminished cFos activation by sucrose ingestion in the nucleus accumbens. Recent single neuron recording studies demonstrated that processing of sucrose-evoked activity in the PBN is altered in the Otsuka Long Evans Tokushima Fatty (OLETF) rats that develop obesity due to chronic overeating and express increased avidity to sweet. Compared with lean controls, taste neurons in OLETF rats had reduced overall sensitivity to sucrose and altered concentration responses: decreased responses to lower and augmented responses to higher concentrations. The decreased sensitivity to sucrose was specific to NaCl-best neurons that also responded to sucrose, but the concentration effects were carried by the sucrose-specific neurons. Collectively, these findings support the hypothesis that the PBN enables taste stimuli to engage the reward system and, in doing so, influences food intake and body weight regulation. Obesity, in turn, may further alter the gustatory code via forebrain connections to the taste relays or hormonal changes consequent to weight gain. PMID:19686159

  20. Effect of starch on the molecular mobility of amorphous sucrose.

    PubMed

    You, Yumin; Ludescher, Richard D

    2011-04-13

    Molecular mobility in amorphous solid biomaterials is modulated by the composition and environment (primarily temperature). Phosphorescence of the triplet probe erythrosin B was used to generate a mobility map within amorphous sucrose films doped with starch ranging from 0.001 to 0.1 g starch/g sucrose. Data on the emission energy and lifetime of erythrosin B in sucrose and sucrose-starch films over the temperature range from 5 to 100 °C indicates that starch influences the molecular mobility as well as dynamic site heterogeneity of amorphous sucrose in a dose-dependent manner. At a starch/sucrose weight (wt) ratio below 0.005, both emission energy and lifetime decreased, and both the dipolar relaxation rate and nonradiative quenching rate k(TS0) increased, indicating that starch increased the matrix molecular mobility. At a ratio above 0.005, both emission energy and lifetime increased, and the dipolar relaxation rate and nonradiative quenching rate decreased, indicating that starch decreased the matrix mobility both in the glass and in the melt. The mobility showed a minimum value at a ratio of 0.01. The interactions existing in the sucrose-starch matrix are considered as the determining factor to influence the molecular mobility of sucrose-starch mixtures. Changes in the distribution of emission energies (emission bandwidth) and lifetimes indicated that starch increased the spectral heterogeneity at high contents while showing insignificant change or a slight decrease in the heterogeneity at low starch contents. These data illustrate the complex effects of a polymer with mainly linear structure and flexible conformation on the mobility of an amorphous, hydrogen bonded sugar matrix. PMID:21381746

  1. Microbial sucrose isomerases: producing organisms, genes and enzymes.

    PubMed

    Goulter, Ken C; Hashimi, Saeed M; Birch, Robert G

    2012-01-01

    Sucrose isomerase (SI) activity is used industrially for the conversion of sucrose into isomers, particularly isomaltulose or trehalulose, which have properties advantageous over sucrose for some food uses. All of the known microbial SIs are TIM barrel proteins that convert sucrose without need for any cofactors, with varying kinetics and product specificities. The current analysis was undertaken to bridge key gaps between the information in patents and scientific publications about the microbes and enzymes useful for sucrose isomer production. This analysis shows that microbial SIs can be considered in 5 structural classes with corresponding functional distinctions that broadly align with the taxonomic differences between producing organisms. The most widely used bacterial strain for industrial production of isomaltulose, widely referred to as "Protaminobacter rubrum" CBS 574.77, is identified as Serratia plymuthica. The strain producing the most structurally divergent SI, with a high product specificity for trehalulose, widely referred to as "Pseudomonas mesoacidophila" MX-45, is identified as Rhizobium sp. Each tested SI-producer is shown to have a single SI gene and enzyme, so the properties reported previously for the isolated proteins can reasonably be associated with the products of the genes subsequently cloned from the same isolates and SI classes. Some natural isolates with potent SI activity do not catabolize the isomer under usual production conditions. The results indicate that their industrial potential may be further enhanced by selection for variants that do not catabolize the sucrose substrate. PMID:22133441

  2. Recurrent selection for sucrose has altered assimilate partitioning between growth and storage in sugarcane internodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sucrose yield in sugarcane is a function of sucrose content of the cane and cane yield. Selection for sucrose content is a high priority in sugarcane breeding programs. Louisiana sugarcane breeding programs have used a modified recurrent selection program whereby genotypes with high sucrose content ...

  3. A novel ultra performance liquid chromatography-tandem mass spectrometry method for the determination of sucrose octasulfate in dog plasma.

    PubMed

    Ke, Yuyong; Li, Steve Lianghong; Chang, Linda Dongxia; Kapanadze, Theo

    2015-01-26

    A novel, specific and sensitive bioanalytical method has been developed for the determination of sucrose octasulfate (SOS) in dog plasma and urine using ion-pair reversed-phase ultraperformance liquid chromatography coupled with electrospray triple quadruple mass spectrometry (IPRP-UPLC ESI MS/MS). (13)C-labeled sucrose octasulfate-(13)C12 sodium salt is used as the internal standard. 200 ?L of plasma or serum sample is extracted using weak anion exchange solid phase cartridge. In this method, a polar amide column is employed for the liquid chromatograph (LC) separation while the diethylamine and formic acid buffer is used as the ion-pairing reagent. The low limitation of quantitation of sucrose octasulfate is 0.20 ng on the column with a signal to noise ratio larger than 50. Parameters such as linearity, accuracy and precision have been validated in full compliance with the FDA guidelines for the bioanalytical method development and validation. A linear regression model fit the calibration curve very well with R>0.99. The bias and coefficient of variation of all levels of QCs are within the range of 15%. The selectivity, matrix effect and stabilities of analytes in solution and matrix have also been evaluated and the results met the acceptance criteria according to the guidelines. Based on these results, the method has qualified to analyze sucrose octasulfate in dog plasma for clinic research. This method has been applied to 1000 preclinical samples. PMID:25553387

  4. Yeast transcription factors Kevin Struhl

    E-print Network

    Yeast transcription factors Kevin Struhl Harvard Medical School, Boston, USA Studies of yeast Transcriptional regulatory mechanisms are fundamentally similar in eukaryotic organisms from yeasts to humans (for reviews of yeast transcription, see [1,2]). Compo- nents of the chromatin template and the basic RNA

  5. Yeast Biomass Production in Brewery's Spent Grains Hemicellulosic Hydrolyzate

    NASA Astrophysics Data System (ADS)

    Duarte, Luís C.; Carvalheiro, Florbela; Lopes, Sónia; Neves, Ines; Gírio, Francisco M.

    Yeast single-cell protein and yeast extract, in particular, are two products which have many feed, food, pharmaceutical, and biotechnological applications. However, many of these applications are limited by their market price. Specifically, the yeast extract requirements for culture media are one of the major technical hurdles to be overcome for the development of low-cost fermentation routes for several top value chemicals in a biorefinery framework. A potential biotechnical solution is the production of yeast biomass from the hemicellulosic fraction stream. The growth of three pentose-assimilating yeast cell factories, Debaryomyces hansenii, Kluyveromyces marxianus, and Pichia stipitis was compared using non-detoxified brewery's spent grains hemicellulosic hydrolyzate supplemented with mineral nutrients. The yeasts exhibited different specific growth rates, biomass productivities, and yields being D. hansenii as the yeast species that presented the best performance, assimilating all sugars and noteworthy consuming most of the hydrolyzate inhibitors. Under optimized conditions, D. hansenii displayed a maximum specific growth rate, biomass yield, and productivity of 0.34 h-1, 0.61 g g-1, and 0.56 g 1-1 h-1, respectively. The nutritional profile of D. hansenii was thoroughly evaluated, and it compares favorably to others reported in literature. It contains considerable amounts of some essential amino acids and a high ratio of unsaturated over saturated fatty acids.

  6. Biotransformation of vegetable and fruit processing wastes into yeast biomass enriched with selenium

    Microsoft Academic Search

    Olena Stabnikova; Jing-Yuan Wang; Hong Bo Ding; Joo-HwaTay

    2005-01-01

    Water extracts of cabbage, watermelon, a mixture of residual biomass of green salads and tropical fruits were used for yeast cultivation. These extracts contained from 1420 to 8900 mg\\/l of dissolved organic matter, and from 600 to 1800 mg\\/l of nitrogen. pH of the extracts was in the range from 4.1 to 6.4. Biomass concentration of yeast, Saccharomyces cerevisiae CEE

  7. Astaxanthinogenesis in the yeast Phaffia rhodozyma - optimization of low-cost culture media and yeast cell-wall lysis

    SciTech Connect

    Fontana, J.D.; Baron, M.; Guimaraes, M.F. [LQBB-Biomass Chemo Biotechnology Lab., Curitiba (Brazil)] [and others

    1997-12-31

    Astaxanthin is a diketo-dihydroxy-carotenoid produced by Phaffia rhodozyma, a basidiomicetous yeast. A low-cost fermentation medium consisting of raw sugarcane juice and urea was developed to exploit the active sucrolytic/urelolytic enzyme apparatus inherent to the yeast. As compared to the beneficial effect of 0.1 g% urea, a ready nitrogen source, mild phosphoric pre inversion of juice sucrose to glucose and fructose, promptly fermentable carbon sources, resulted in smaller benefits. Corn steep liquor (CSL) was found to be a valuable supplement for both yeast biomass yield (9.2 g dry cells/L) and astaxanthin production (1.3 mg/g cells). Distillery effluent (vinace), despite only a slightly positive effect on yeast growth, allowed for the highest pigment productivity (1.9 mg/g cells). Trace amounts of Ni{sup 2} (1 mg/L, as a cofactor for urease) resulted in controversial effects, namely, biomass decrease and astaxanthin increase, with no effect on the release (and uptake) of ammonium ion from urea. 13 refs., 6 figs.

  8. The Mode of Sucrose Degradation in Potato Tubers Determines the Fate of Assimilate Utilization

    PubMed Central

    Ferreira, Stephanus J.; Sonnewald, Uwe

    2012-01-01

    Cytosolic (U-IN-2) or apoplasmic (U-IN-1) targeting of yeast invertase in potato tubers leads to a reduction in sucrose and an increase in glucose content, but specific phenotypical changes are dependent on the subcellular targeting of the enzyme. Cytosolic expression leads to a more severe phenotype with the most striking aspects being reduced starch content and increased respiration. Despite extensive research, the regulatory mechanisms leading to these changes remain obscure. Recent technological advancements regarding potato transcriptional and genomic research presented us with the opportunity to revisit these lines and perform detailed gene expression analysis, in combination with extensive metabolic profiling, to identify regulatory networks underlying the observed changes. Our results indicate that in both genotypes reduced UDP-glucose production is associated with a reduced expression of cell wall biosynthetic genes. In addition, U-IN-1 tubers are characterized by elevated expression of senescence-associated genes, coupled to reduced expression of genes related to photosynthesis and the cytoskeleton. We provide evidence that increased respiration, observed specifically in U-IN-2 tubers, might be due to sugar signaling via released trehalose-6-phosphate inhibition of the SnRK1 complex. In both genotypes, expression of the plastidic glucose-6-phosphate transporter (GPT) is significantly down-regulated. This leads to a shift in the cytosolic to plastidic glucose-6-phosphate ratio and hence might limit starch synthesis but also the oxidative pentose phosphate pathway. This might explain the observed changes in several additional plastid localized pathways, most notably reduced expression of fatty acid biosynthetic genes and an accumulation of shikimate. Interestingly, a strict negative correlation between invertase and GPT expression could be observed in a wide range of potato tubers. This reciprocal regulation may be part of a more general switch controlling energy versus storage metabolism, suggesting that the fate of assimilate utilization is coordinated at the level of sucrose degradation. PMID:22639642

  9. Effect of sucrose on the metabolic disposition of aspartame.

    PubMed

    Stegink, L D; Brummel, M C; Persoon, T J; Filer, L J; Bell, E F; Ziegler, E E

    1990-08-01

    Twelve normal adult subjects ingested a beverage providing 0.136 mmol aspartame/kg body wt on 2 different days. On 1 study day the beverage provided only aspartame, on the other the beverage provided both aspartame and 3.51 mmol sucrose/kg body wt. The high mean plasma phenylalanine concentrations were similar after administration of aspartame alone (158 +/- 28.9 mumol/L, mean +/- SD) and administration of aspartame plus sucrose (134 +/- 44.1 mumol/L). Evaluation of the area under the plasma concentration-time curve (AUC) for phenylalanine also showed no significant difference between groups (197 +/- 49.1 vs 182 +/- 28.3 mumol.L-1.h for aspartame alone and aspartame plus sucrose, respectively). Similarly, the high mean ratio of phenylalanine to large neutral amino acids (Phe:LNAA) in plasma did not differ significantly (0.265 +/- 0.046 for aspartame alone, 0.275 +/- 0.107 for aspartame plus sucrose). However, there was a small but significant difference between groups for the 4-h AUC values for plasma Phe:LNAA. The simultaneous ingestion of sucrose with aspartame had only minor effects on aspartame's metabolic disposition. PMID:2197852

  10. Yeast expression platforms

    Microsoft Academic Search

    Erik Böer; Gerhard Steinborn; Gotthard Kunze; Gerd Gellissen

    2007-01-01

    Yeasts provide attractive expression platforms. They combine ease of genetic manipulations and the option for a simple fermentation\\u000a design of a microbial organism with the capabilities of an eukaryotic organism to secrete and to modify a protein according\\u000a to a general eukaryotic scheme. For platform applications, a range of yeast species has been developed during the last decades.\\u000a We present

  11. Nitrile Metabolizing Yeasts

    NASA Astrophysics Data System (ADS)

    Bhalla, Tek Chand; Sharma, Monica; Sharma, Nitya Nand

    Nitriles and amides are widely distributed in the biotic and abiotic components of our ecosystem. Nitrile form an important group of organic compounds which find their applications in the synthesis of a large number of compounds used as/in pharmaceutical, cosmetics, plastics, dyes, etc>. Nitriles are mainly hydro-lyzed to corresponding amide/acid in organic chemistry. Industrial and agricultural activities have also lead to release of nitriles and amides into the environment and some of them pose threat to human health. Biocatalysis and biotransformations are increasingly replacing chemical routes of synthesis in organic chemistry as a part of ‘green chemistry’. Nitrile metabolizing organisms or enzymes thus has assumed greater significance in all these years to convert nitriles to amides/ acids. The nitrile metabolizing enzymes are widely present in bacteria, fungi and yeasts. Yeasts metabolize nitriles through nitrilase and/or nitrile hydratase and amidase enzymes. Only few yeasts have been reported to possess aldoxime dehydratase. More than sixty nitrile metabolizing yeast strains have been hither to isolated from cyanide treatment bioreactor, fermented foods and soil. Most of the yeasts contain nitrile hydratase-amidase system for metabolizing nitriles. Transformations of nitriles to amides/acids have been carried out with free and immobilized yeast cells. The nitrilases of Torulopsis candida>and Exophiala oligosperma>R1 are enantioselec-tive and regiospecific respectively. Geotrichum>sp. JR1 grows in the presence of 2M acetonitrile and may have potential for application in bioremediation of nitrile contaminated soil/water. The nitrilase of E. oligosperma>R1 being active at low pH (3-6) has shown promise for the hydroxy acids. Immobilized yeast cells hydrolyze some additional nitriles in comparison to free cells. It is expected that more focus in future will be on purification, characterization, cloning, expression and immobilization of nitrile metabolizing enzymes of yeasts.

  12. Biochemical Comparison of Commercial Selenium Yeast Preparations.

    PubMed

    Fagan, Sheena; Owens, Rebecca; Ward, Patrick; Connolly, Cathal; Doyle, Sean; Murphy, Richard

    2015-08-01

    The trace mineral selenium (Se) is an essential element for human and animal nutrition. The addition of Se to the diet through dietary supplements or fortified food/feed is increasingly common owing to the often sub-optimal content of standard diets of many countries. Se supplements commercially available include the inorganic mineral salts such as sodium selenite or selenate, and organic forms such as Se-enriched yeast. Today, Se yeast is produced by several manufacturers and has become the most widely used source of Se for human supplementation and is also widely employed in animal nutrition where approval in all species has been granted by regulatory bodies such as the European Food Safety Authority (EFSA). Characterisation and comparison of Se-enriched yeast products has traditionally been made by quantifying total selenomethionine (SeMet) content. A disadvantage of this approach, however, is that it does not consider the effects of Se deposition on subsequent digestive availability. In this study, an assessment was made of the water-soluble extracts of commercially available Se-enriched yeast samples for free, peptide-bound and total water-soluble SeMet. Using LC-MS/MS, a total of 62 Se-containing proteins were identified across four Se yeast products, displaying quantitative/qualitative changes in abundance relative to the certified reference material, SELM-1 (P value <0.05; fold change ?2). Overall, the study indicates that significant differences exist between Se yeast products in terms of SeMet content, Se-containing protein abundance and associated metabolic pathways. PMID:25855372

  13. Forces in yeast flocculation

    NASA Astrophysics Data System (ADS)

    El-Kirat-Chatel, Sofiane; Beaussart, Audrey; Vincent, Stéphane P.; Abellán Flos, Marta; Hols, Pascal; Lipke, Peter N.; Dufrêne, Yves F.

    2015-01-01

    In the baker's yeast Saccharomyces cerevisiae, cell-cell adhesion (``flocculation'') is conferred by a family of lectin-like proteins known as the flocculin (Flo) proteins. Knowledge of the adhesive and mechanical properties of flocculins is important for understanding the mechanisms of yeast adhesion, and may help controlling yeast behaviour in biotechnology. We use single-molecule and single-cell atomic force microscopy (AFM) to explore the nanoscale forces engaged in yeast flocculation, focusing on the role of Flo1 as a prototype of flocculins. Using AFM tips labelled with mannose, we detect single flocculins on Flo1-expressing cells, showing they are widely exposed on the cell surface. When subjected to force, individual Flo1 proteins display two distinct force responses, i.e. weak lectin binding forces and strong unfolding forces reflecting the force-induced extension of hydrophobic tandem repeats. We demonstrate that cell-cell adhesion bonds also involve multiple weak lectin interactions together with strong unfolding forces, both associated with Flo1 molecules. Single-molecule and single-cell data correlate with microscale cell adhesion behaviour, suggesting strongly that Flo1 mechanics is critical for yeast flocculation. These results favour a model in which not only weak lectin-sugar interactions are involved in yeast flocculation but also strong hydrophobic interactions resulting from protein unfolding.

  14. Enzymic Components of Sucrose Accumulation in the Wild Tomato Species Lycopersicon peruvianum

    PubMed Central

    Stommel, John R.

    1992-01-01

    Sugar and soluble solids content and invertase (EC 3.2.1.26), sucrose synthase (EC 2.4.1.13), and sucrose phosphate synthase (EC 2.4.1.14) enzyme activities were measured throughout fruit development in tomato (Lycopersicon esculentum Mill.) and the green fruited species Lycopersicon peruvianum. Fruit of L. peruvianum accumulated predominantly sucrose, in contrast with hexose accumulation, which is characteristic of L. esculentum. The percentage of soluble solids in ripe L. peruvianum fruit was more than twice that present in L. esculentum and attributed primarily to the high level of sucrose accumulated in L. peruvianum. Low levels of invertase and sucrose synthase activity were associated with the period of significant sucrose accumulation and storage in L. peruvianum. Increased sucrose phosphate synthase activity was observed during the latter stages of fruit development in sucrose-accumulating fruit but was not coincident with maximum rates of sucrose accumulation. PMID:16668869

  15. Avocado Oil Supplementation Modifies Cardiovascular Risk Profile Markers in a Rat Model of Sucrose-Induced Metabolic Changes

    PubMed Central

    Carvajal-Zarrabal, Octavio; Nolasco-Hipolito, Cirilo; Aguilar-Uscanga, M. Guadalupe; Melo-Santiesteban, Guadalupe; Hayward-Jones, Patricia M.; Barradas-Dermitz, Dulce M.

    2014-01-01

    The purpose of this study was to evaluate the effects of avocado oil administration on biochemical markers of cardiovascular risk profile in rats with metabolic changes induced by sucrose ingestion. Twenty-five rats were divided into five groups: a control group (CG; basic diet), a sick group (MC; basic diet plus 30% sucrose solution), and three other groups (MCao, MCac, and MCas; basic diet plus 30% sucrose solution plus olive oil and avocado oil extracted by centrifugation or using solvent, resp.). Glucose, total cholesterol, triglycerides, phospholipids, low- and high-density lipoproteins (LDL, HDL), very low-density lipoprotein (VLDL), lactic dehydrogenase, creatine kinase, and high sensitivity C-reactive protein concentration were analyzed. Avocado oil reduces TG, VLDL, and LDL levels, in the LDL case significantly so, without affecting HDL levels. An effect was exhibited by avocado oil similar to olive oil, with no significant difference between avocado oil extracted either by centrifugation or solvent in myocardial injury biochemical indicators. Avocado oil decreased hs-CRP levels, indicating that inflammatory processes were partially reversed. These findings suggested that avocado oil supplementation has a positive health outcome because it reduces inflammatory events and produces positive changes in the biochemical indicators studied, related to the development of metabolic syndrome. PMID:24719499

  16. Fatal anaphylactic reaction to iron sucrose in pregnancy.

    PubMed

    Mishra, Ajay; Dave, Nikhil; Viradiya, Kishor

    2013-01-01

    Iron-deficiency anemia in pregnancy can have serious deleterious effects for both mother and fetus. Parenteral iron therapy in iron-deficiency anemia is recommended in patients where oral iron therapy is ineffective due to malabsorption states and non-compliance. Compared to oral iron therapy, intravenous iron results in much more rapid resolution of iron-deficiency anemia with minimal adverse reactions. Iron sucrose has a favorable safety profile and is an alternative to other forms of parenteral iron therapy in correction of iron stores depletion. Immune mechanisms and iron agent releasing bioactive, partially unbound iron into the circulation, resulting in oxidative stress appears to cause severe adverse reactions. Although iron sucrose has a favorable safety profile in comparison to other parenteral iron preparations, this report highlights a fatal anaphylactic shock to iron sucrose in a pregnant woman with severe iron deficiency non-compliant to oral iron therapy. PMID:23543624

  17. Fatal anaphylactic reaction to iron sucrose in pregnancy

    PubMed Central

    Mishra, Ajay; Dave, Nikhil; Viradiya, Kishor

    2013-01-01

    Iron-deficiency anemia in pregnancy can have serious deleterious effects for both mother and fetus. Parenteral iron therapy in iron-deficiency anemia is recommended in patients where oral iron therapy is ineffective due to malabsorption states and non-compliance. Compared to oral iron therapy, intravenous iron results in much more rapid resolution of iron-deficiency anemia with minimal adverse reactions. Iron sucrose has a favorable safety profile and is an alternative to other forms of parenteral iron therapy in correction of iron stores depletion. Immune mechanisms and iron agent releasing bioactive, partially unbound iron into the circulation, resulting in oxidative stress appears to cause severe adverse reactions. Although iron sucrose has a favorable safety profile in comparison to other parenteral iron preparations, this report highlights a fatal anaphylactic shock to iron sucrose in a pregnant woman with severe iron deficiency non-compliant to oral iron therapy. PMID:23543624

  18. Difructosan anhydrides III preparation from sucrose by coupled enzyme reaction.

    PubMed

    Hang, Hua; Miao, Ming; Li, Yungao; Jiang, Bo; Mu, Wanmeng; Zhang, Tao

    2013-02-15

    Difructosan anhydrides III (DFA III) preparation was usually obtained by inulin hydrolysis with inulin fructotransferase (IFTase). The fructofuranosidic linkages of inulin were the same as fructooligosaccharides (FOS), which was synthesized by sucrose with fructosyltransferase (FTase). FOS was mainly composed of 1-kestose (GF(2)), nystose (GF(3)) and fructofuranosylnystose (GF(4)), and nystose was observed to be the smallest substrate for IFTase to synthesize DFA III. So sucrose, much cheaper than inulin, was considered to produce DFA III by coupled FTase and IFTase reaction. DFA III yield was obtained about 100mg/g (DFA III weight/sucrose weight) through this method. The results demonstrated the high potential of the coupled enzyme reaction as a novel DFA III producing method. PMID:23399196

  19. Electrogenic Sucrose Transport in Developing Soybean Cotyledons 12

    PubMed Central

    Lichtner, Francis T.; Spanswick, Roger M.

    1981-01-01

    Addition of sucrose to a solution bathing an excised developing soybean cotyledon causes a transient depolarization of the membrane potential, as measured using standard electrophysiological techniques. The magnitude of the depolarization is dependent on the concentration of both sucrose and protons in a manner which suggests carrier mediation; this process has an apparent Km for sucrose of about 10 millimolar. Agents interfering with the generation or maintenance of a proton electrochemical gradient eliminate these depolarizations. Electrogenic sugar transport is sensitive to sulfhydryl-modifying reagents; their effect appears to be through a direct interaction with the carrier protein and/or with the process establishing the proton electrochemical gradient across the plasma membrane. p-Chloromercuribenzene sulfonate appears to be a selective inhibitor of the carrier-mediated process itself. PMID:16661771

  20. New rat models of iron sucrose-induced iron overload.

    PubMed

    Vu'o'ng Lê, Bá; Khorsi-Cauet, Hafida; Villegier, Anne-Sophie; Bach, Véronique; Gay-Quéheillard, Jérôme

    2011-07-01

    The majority of murine models of iron sucrose-induced iron overload were carried out in adult subjects. This cannot reflect the high risk of iron overload in children who have an increased need for iron. In this study, we developed four experimental iron overload models in young rats using iron sucrose and evaluated different markers of iron overload, tissue oxidative stress and inflammation as its consequences. Iron overload was observed in all iron-treated rats, as evidenced by significant increases in serum iron indices, expression of liver hepcidin gene and total tissue iron content compared with control rats. We also showed that total tissue iron content was mainly associated with the dose of iron whereas serum iron indices depended essentially on the duration of iron administration. However, no differences in tissue inflammatory and antioxidant parameters from controls were observed. Furthermore, only rats exposed to daily iron injection at a dose of 75 mg/kg body weight for one week revealed a significant increase in lipid peroxidation in iron-treated rats compared with their controls. The present results suggest a correlation between iron overload levels and the dose of iron, as well as the duration and frequency of iron injection and confirm that iron sucrose may not play a crucial role in inflammation and oxidative stress. This study provides important information about iron sucrose-induced iron overload in rats and may be useful for iron sucrose therapy for iron deficiency anemia as well as for the prevention and diagnosis of iron sucrose-induced iron overload in pediatric patients. PMID:21685238

  1. Identification of actively filling sucrose sinks. [Solanum tuberosum; Phaseolus lunatus; Manihot esculenta; Liquidambar styraciflua L. ; Carya illinoinensis

    Microsoft Academic Search

    Shijean S. Sung; Dianpeng Xu; Black C. C

    1989-01-01

    Certain actively filling plant sucrose sinks such as a seed, a tuber, or a root can be identified by measuring the uridine diphosphate and pyrophosphate-dependent metabolism of sucrose. Sucrolysis in both active and quiescent sucrose sinks was tested and sucrose synthase was found to be the predominant sucrose breakdown activity. Sucrolysis via invertases was low and secondary in both types

  2. Microbiological characteristics and physiological functionality of new records of yeasts from wild flowers in yokjido, Korea.

    PubMed

    Hyun, Se-Hee; Lee, Jong-Soo

    2014-06-01

    Two new yeast records, Cryptococcus adeliensis YJ19-2 and Cryptococcus uzbekistanensis YJ10-4 were screened from 60 yeasts strains that were isolated and identified from wild flowers in Yokjido, Gyeongsangnam-do, Korea. The morphological and cultural characteristics of the newly recorded yeasts and the physiological functionalities of the supernatants and cell-free extracts obtained from their cultures were investigated. The two newly recorded yeasts did not form ascospores and pseudomycelia. They also grew well in yeast extract-peptone-dextrose broth. C. uzbekistanensis YJ10-4 grew in a vitamin-free medium and was also tolerant to sugar and salt. Antihypertensive angiotensin I-converting enzyme inhibitory activity of the supernatant from C. adeliensis YJ19-2 was high (71.8%) and its cell-free extract also showed very high (81.2%) antidiabetic á-glucosidase inhibitory activity. PMID:25071392

  3. Microbiological Characteristics and Physiological Functionality of New Records of Yeasts from Wild Flowers in Yokjido, Korea

    PubMed Central

    Hyun, Se-Hee

    2014-01-01

    Two new yeast records, Cryptococcus adeliensis YJ19-2 and Cryptococcus uzbekistanensis YJ10-4 were screened from 60 yeasts strains that were isolated and identified from wild flowers in Yokjido, Gyeongsangnam-do, Korea. The morphological and cultural characteristics of the newly recorded yeasts and the physiological functionalities of the supernatants and cell-free extracts obtained from their cultures were investigated. The two newly recorded yeasts did not form ascospores and pseudomycelia. They also grew well in yeast extract-peptone-dextrose broth. C. uzbekistanensis YJ10-4 grew in a vitamin-free medium and was also tolerant to sugar and salt. Antihypertensive angiotensin I-converting enzyme inhibitory activity of the supernatant from C. adeliensis YJ19-2 was high (71.8%) and its cell-free extract also showed very high (81.2%) antidiabetic á-glucosidase inhibitory activity. PMID:25071392

  4. Method for converting sucrose to .beta.-D-glucose

    DOEpatents

    Simmons, Blake A. (San Francisco, CA); Volponi, Joanne V. (Livermore, CA); Ingersoll, David (Albuquerque, NM); Walker, Andrew (Woodinville, WA)

    2009-07-07

    Disclosed is an apparatus and method for continuously converting sucrose to .beta.-D-glucose. The method comprises a three-stage enzymatic reactor in which an aqueous solution of sucrose is first converted into a solution of fructose and .alpha.-D-glucose by passing it through a porous, packed column containing an inert media on which invertase is immobilized. This solution is then sent through a second packed column containing glucose isomerase and finally a third packed column containing mutarotase. Solution temperature and pH are adjusted to maximize glucose output.

  5. Sucrose: A prospering and sustainable organic raw material.

    PubMed

    Peters, Siegfried; Rose, Thomas; Moser, Matthias

    2010-01-01

    Sucrose (alpha-D-glucopyranosyl-(1-->2)-beta-D-fructofuranoside) is an inexpensive chemical produced by sugar cane and sugar beet cultivation. Chemical and/or biochemical transformations convert it into highly valuable synthetic intermediates such as 5-hydroxymethylfurfural (HMF), bioethylene, 1,2-propylene glycol and levulinic acid. Sucrose can also be converted into biodegradable polymers such as polyesters and polyurethanes, as well as into novel carbohydrates such as isomaltulose, trehalulose, inulin, levan, Neo-amylose, and dextran, highly valuable additives for food and cosmetics and materials for separation and purification technologies. PMID:21626746

  6. Development and Validation of an In-House Database for Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry-Based Yeast Identification Using a Fast Protein Extraction Procedure

    PubMed Central

    De Carolis, Elena; Vella, Antonietta; Vaccaro, Luisa; Torelli, Riccardo; Posteraro, Patrizia; Ricciardi, Walter; Posteraro, Brunella

    2014-01-01

    In recent studies evaluating the usefulness of the matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS)-based identification of yeasts for the routine diagnosis of fungal infections, preanalytical sample processing has emerged as a critical step for reliable MALDI-TOF MS outcomes, especially when the Bruker Daltonics Biotyper software was used. In addition, inadequate results often occurred due to discrepancies between the methods used for clinical testing and database construction. Therefore, we created an in-house MALDI-TOF MS library using the spectra from 156 reference and clinical yeast isolates (48 species in 11 genera), which were generated with a fast sample preparation procedure. After a retrospective validation study, our database was evaluated on 4,232 yeasts routinely isolated during a 6-month period and fast prepared for MALDI-TOF MS analysis. Thus, 4,209 (99.5%) of the isolates were successfully identified to the species level (with scores of ?2.0), with 1,676 (39.6%) having scores of >2.3. For the remaining 23 (0.5%) isolates, no reliable identification (with scores of <1.7) was obtained. Interestingly, these isolates were almost always from species uniquely represented or not included in the database. As the MALDI-TOF MS results were, except for 23 isolates, validated without additional phenotypic or molecular tests, our proposed strategy can enhance the rapidity and accuracy of MALDI-TOF MS in identifying medically important yeast species. However, while continuous updating of our database will be necessary to enrich it with more strains/species of new and emerging yeasts, the present in-house MALDI-TOF MS library can be made publicly available for future multicenter studies. PMID:24554755

  7. Fructanase and fructosyltransferase activity of non-Saccharomyces yeasts isolated from fermenting musts of Mezcal.

    PubMed

    Arrizon, Javier; Morel, Sandrine; Gschaedler, Anne; Monsan, Pierre

    2012-04-01

    Fructanase and fructosyltransferase are interesting for the tequila process and prebiotics production (functional food industry). In this study, one hundred thirty non-Saccharomyces yeasts isolated from "Mezcal de Oaxaca" were screened for fructanase and fructosyltransferase activity. On solid medium, fifty isolates grew on Agave tequilana fructans (ATF), inulin or levan. In liquid media, inulin and ATF induced fructanase activities of between 0.02 and 0.27U/ml depending of yeast isolate. High fructanase activity on sucrose was observed for Kluyveromyces marxianus and Torulaspora delbrueckii, while the highest fructanase activity on inulin and ATF was observed for Issatchenkia orientalis, Cryptococcus albidus, and Candida apicola. Zygosaccharomyces bisporus and Candida boidinii had a high hydrolytic activity on levan. Sixteen yeasts belonging to K. marxianus, T. delbrueckii and C. apicola species were positive for fructosyltransferase activity. Mezcal microbiota proved to showed to be a source for new fructanase and fructosyltransferases with potential application in the tequila and food industry. PMID:22336744

  8. Rapid isolation of yeast genomic DNA: Bust n' Grab

    PubMed Central

    Harju, Susanna; Fedosyuk, Halyna; Peterson, Kenneth R

    2004-01-01

    Background Mutagenesis of yeast artificial chromosomes (YACs) often requires analysis of large numbers of yeast clones to obtain correctly targeted mutants. Conventional ways to isolate yeast genomic DNA utilize either glass beads or enzymatic digestion to disrupt yeast cell wall. Using small glass beads is messy, whereas enzymatic digestion of the cells is expensive when many samples need to be analyzed. We sought to develop an easier and faster protocol than the existing methods for obtaining yeast genomic DNA from liquid cultures or colonies on plates. Results Repeated freeze-thawing of cells in a lysis buffer was used to disrupt the cells and release genomic DNA. Cell lysis was followed by extraction with chloroform and ethanol precipitation of DNA. Two hundred ng – 3 ?g of genomic DNA could be isolated from a 1.5 ml overnight liquid culture or from a large colony. Samples were either resuspended directly in a restriction enzyme/RNase coctail mixture for Southern blot hybridization or used for several PCR reactions. We demonstrated the utility of this method by showing an analysis of yeast clones containing a mutagenized human ?-globin locus YAC. Conclusion An efficient, inexpensive method for obtaining yeast genomic DNA from liquid cultures or directly from colonies was developed. This protocol circumvents the use of enzymes or glass beads, and therefore is cheaper and easier to perform when processing large numbers of samples. PMID:15102338

  9. Expression and activity analysis of sucrose:sucrose 1-fructosyltransferase from onion.

    PubMed

    Han, Yawei; Chen, Liping; Mao, Duobin; Tang, Lijun; Guan, Lihong

    2010-09-30

    This study was designed to express the onion fructosyltransferase by Escherichia coli DH5alpha, and obtain the optimal conditions of FST-1 activity. Thereby, fructosyltransferase gene was obtained by RT-PCR from onion in this experiment, and named FST-1. The expressed proteins were analyzed by SDS-PAGE. FST-1 activity was identified by the high performance liquid chromatography (HPLC). The optimal conditions of FST-1 were analyzed by the dinonylnaphthalene sulfonic acid (DNS) and orthogonal test. Results revealed that FST-1 was identified to 98% similarity with fructosyltransferase mRNA of onion (accession number: AJ006066). FST-1 was successfully expressed in E. coli DH5alpha. HPLC results indicated that the expressed protein from FST-1 had a good transferring activity for fructose. The optimal conditions of FST-1 in catalyzing reaction were the pH 5.0, 45 degrees C and 60% sucrose substrate. The results in this experiment would lay the foundation for the large-scale of kestose by bio-catalysis method. PMID:20188876

  10. Evolutionary history of Ascomyceteous Yeasts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yeasts are important for many industrial and biotechnological processes and show remarkable diversity despite morphological similarities. We have sequenced the genomes of 20 ascomyceteous yeasts of taxonomic and industrial importance including members of Saccharomycotina and Taphrinomycotina. A comp...

  11. Sucrose Responsiveness, Learning Success, and Task Specialization in Ants

    ERIC Educational Resources Information Center

    Perez, Margot; Rolland, Uther; Giurfa,, Martin; d'Ettorre, Patrizia

    2013-01-01

    Social insects possess remarkable learning capabilities, which are crucial for their ecological success. They also exhibit interindividual differences in responsiveness to environmental stimuli, which underlie task specialization and division of labor. Here we investigated for the first time the relationships between sucrose responsiveness,…

  12. Optimal design and operation of SMB bioreactor for sucrose inversion

    Microsoft Academic Search

    Anjushri S. Kurup; Hariprasad J. Subramani; K. Hidajat; Ajay K. Ray

    2005-01-01

    A comprehensive optimization study was carried out to evaluate the performance of a simulated moving bed reactor (SMBR) system for an industrially important biochemical reaction-separation problem, the inversion of Sucrose and the in situ separation of the products, glucose and fructose. Two modifications of SMBR are studied, one in which non-synchronous switching is used to vary the number of columns

  13. A complete characterization of the vibrational spectra of sucrose.

    PubMed

    Brizuela, Alicia Beatriz; Bichara, Laura Cecilia; Romano, Elida; Yurquina, Alisia; Locatelli, Silvano; Brandán, Silvia Antonia

    2012-11-01

    We combined experimental vibrational spectroscopy (FTIR-Raman) and ab-initio calculations based on density functional theory (DFT) to predict the structural and vibrational properties of sucrose in solid phase. The structural properties of sucrose, such as the bond order, possible charge-transfer, and the topological properties of the glucopyran and glucofuran rings were studied by means of the Natural Bond Orbital (NBO) and Atoms in Molecules theory (AIM) investigation. For a complete assignment of the infrared and Raman spectra, the density functional theory (DFT) calculations were combined with Pulay's Scaled Quantum Mechanics Force Field (SQMFF) methodology in order to fit the theoretical frequency values to the experimental ones. An agreement between theoretical and available experimental results was found. A complete assignment of the 129 normal vibration modes for sucrose was performed. Five very intense characteristic bands in the infrared spectrum of sucrose at 3391, 3339, 1069, 1053, and 991 cm(-1) were assigned, the first two to the OH stretching modes while the other ones to C-O stretching modes. PMID:22878022

  14. Sugarcane bagasse hydrolysis using yeast cellulolytic enzymes.

    PubMed

    Souza, Angelica Cristina de; Carvalho, Fernanda Paula; Silva e Batista, Cristina Ferreira; Schwan, Rosane Freitas; Dias, Disney Ribeiro

    2013-10-28

    Ethanol fuel production from lignocellulosic biomass is emerging as one of the most important technologies for sustainable development. To use this biomass, it is necessary to circumvent the physical and chemical barriers presented by the cohesive combination of the main biomass components, which hinders the hydrolysis of cellulose and hemicellulose into fermentable sugars. This study evaluated the hydrolytic capacity of enzymes produced by yeasts, isolated from the soils of the Brazilian Cerrado biome (savannah) and the Amazon region, on sugarcane bagasse pre-treated with H2SO4. Among the 103 and 214 yeast isolates from the Minas Gerais Cerrado and the Amazon regions, 18 (17.47%) and 11 (5.14%) isolates, respectively, were cellulase-producing. Cryptococcus laurentii was prevalent and produced significant ?- glucosidase levels, which were higher than the endo- and exoglucanase activities. In natura sugarcane bagasse was pre-treated with 2% H2SO4 for 30 min at 150oC. Subsequently, the obtained fibrous residue was subjected to hydrolysis using the Cryptococcus laurentii yeast enzyme extract for 72 h. This enzyme extract promoted the conversion of approximately 32% of the cellulose, of which 2.4% was glucose, after the enzymatic hydrolysis reaction, suggesting that C. laurentii is a good ?-glucosidase producer. The results presented in this study highlight the importance of isolating microbial strains that produce enzymes of biotechnological interest, given their extensive application in biofuel production. PMID:23851270

  15. Virtual Yeast Cell

    NSDL National Science Digital Library

    Learning about the various parts of a cell can be tricky business, but this virtual yeast cell offered by The University of Nottingham will come in handy for biology students and science instructors. This learning resource was created to help students in the brewing science program learn about yeast cytology, though just about anyone with an interest in cells will learn something from visiting the site. After entering the interactive cell, visitors can click on different parts of the cell (such as the cytoplasm or the nucleus) in order to learn more about the importance of each one. Visitors should remember that they can also download the virtual yeast cell and use it in the classroom or just with a group of friends.

  16. Yeast killer systems.

    PubMed Central

    Magliani, W; Conti, S; Gerloni, M; Bertolotti, D; Polonelli, L

    1997-01-01

    The killer phenomenon in yeasts has been revealed to be a multicentric model for molecular biologists, virologists, phytopathologists, epidemiologists, industrial and medical microbiologists, mycologists, and pharmacologists. The surprisingly widespread occurrence of the killer phenomenon among taxonomically unrelated microorganisms, including prokaryotic and eukaryotic pathogens, has engendered a new interest in its biological significance as well as its theoretical and practical applications. The search for therapeutic opportunities by using yeast killer systems has conceptually opened new avenues for the prevention and control of life-threatening fungal diseases through the idiotypic network that is apparently exploited by the immune system in the course of natural infections. In this review, the biology, ecology, epidemiology, therapeutics, serology, and idiotypy of yeast killer systems are discussed. PMID:9227858

  17. Passivation Polymer Bulking Versus Sucrose Impregnation: A Cross-Methodological Approach to the Conservation of Leather

    E-print Network

    White, Laura Gail

    2008-08-19

    of polymer bulking and sucrose impregnation confirmed the superiority of samples treated with Passivation Polymer technology in terms of retaining diagnostic characteristics. However, it also proved that sucrose impregnation may serve as a quick, cheap...

  18. Yeast Metabolism Lab Mrs. Zimmerman

    E-print Network

    Rose, Michael R.

    Yeast Metabolism Lab Mrs. Zimmerman 10/22/10 #12;Photosynthesis 6 CO2 + 6 H2O C6H12O6 + 6 O2 Oxygen Glucose Carbon Dioxide Water Energy #12;Yeast · Unicellular · Eukaryotic (like us) · Kingdom Fungi" Saccharomyces cerevisiae #12;Alcoholic Fermentation · Some organisms, including yeast, can create energy without

  19. Sucrose substitutes affect the cariogenic potential of Streptococcus mutans biofilms.

    PubMed

    Durso, S C; Vieira, L M; Cruz, J N S; Azevedo, C S; Rodrigues, P H; Simionato, M R L

    2014-01-01

    Streptococcus mutans is considered the primary etiologic agent of dental caries and contributes significantly to the virulence of dental plaque, especially in the presence of sucrose. To avoid the role of sucrose on the virulence factors of S. mutans, sugar substitutes are commonly consumed because they lead to lower or no production of acids and interfere with biofilm formation. This study aimed to investigate the contribution of sugar substitutes in the cariogenic potential of S. mutans biofilms. Thus, in the presence of sucrose, glucose, sucralose and sorbitol, the biofilm mass was quantified up to 96 h, the pH of the spent culture media was measured, the expression of biofilm-related genes was determined, and demineralization challenge experiments were conduct in enamel fragments. The presence of sugars or sugar substitutes profoundly affected the expression of spaP, gtfB, gtfC, gbpB, ftf, vicR and vicX in either biofilm or planktonic cells. The substitution of sucrose induced a down-regulation of most genes involved in sucrose-dependent colonization in biofilm cells. When the ratio between the expression of biofilm and planktonic cells was considered, most of those genes were down-regulated in biofilm cells in the presence of sugars and up-regulated in the presence of sugar substitutes. However, sucralose but not sorbitol fulfilled the purpose of reducing the cariogenic potential of the diet since it induced the biofilm formation with the lowest biomass, did not change the pH of the medium and led to the lowest lesion depth in the cariogenic challenge. PMID:24481032

  20. Genetics of Yeasts

    NASA Astrophysics Data System (ADS)

    Querol, Amparo; Fernández-Espinar, M. Teresa; Belloch, Carmela

    The use of yeasts in biotechnology processes dates back to ancient days. Before 7000 BC, beer was produced in Sumeria. Wine was made in Assyria in 3500 BC, and ancient Rome had over 250 bakeries, which were making leavened bread by 100 BC. And milk has been made into Kefyr and Koumiss in Asia for many centuries (Demain, Phaff, & Kurtzman, 1999). However, the importance of yeast in the food and beverage industries was only realized about 1860, when their role in food manufacturing became evident.

  1. Effect of Dietary Intake of Avocado Oil and Olive Oil on Biochemical Markers of Liver Function in Sucrose-Fed Rats

    PubMed Central

    Carvajal-Zarrabal, Octavio; Nolasco-Hipolito, Cirilo; Aguilar-Uscanga, Ma. Guadalupe; Melo Santiesteban, Guadalupe; Hayward-Jones, Patricia M.; Barradas-Dermitz, Dulce Ma.

    2014-01-01

    Metabolic changes, along with cardiovascular and hepatic factors, are associated with the development of diseases such as diabetes, dyslipidemia, and obesity. We evaluated the effect of avocado oil supplementation (centrifuged and solvent extracted), compared with olive oil, upon the hepatic function in sucrose-fed rats. Twenty-five rats were divided into five groups: control (basal diet), a sucrose-fed group (basal diet plus 30% sucrose solution), and three other groups (S-OO, S-AOC, and S-AOS, indicating basal diet plus 30% sucrose solution plus olive oil OO, avocado oil extracted by centrifugation AOC or using solvent AOS, resp.). Glucose, total cholesterol, triglycerides, total protein, albumin, globulin, direct bilirubin, glutamic pyruvic transaminase, glutamic oxaloacetic transaminase, alkaline phosphatase, cholinesterase, and ?-amylase concentrations were determined and avocado oil effect on them was studied. In some cases the induced metabolic alteration significantly affected total protein and bilirubin levels and also had a highly significant effect on ?-amylase levels. AOC and AOS exhibited effects similar to those of olive oil, according to the nonsignificant difference in fatty acid profile observed by other authors. Avocado oil consumption could be beneficial in the control of altered metabolic profile illnesses as it presents effects on hepatic function biochemical markers similar to olive oil. PMID:24860825

  2. Antimicrobial activity of Epilobium spp. extracts.

    PubMed

    Battinelli, L; Tita, B; Evandri, M G; Mazzanti, G

    2001-01-01

    The antimicrobial activity of the Epilobium angustifolium, E. hirsutum, E. palustre, E. tetragonum and E. rosmarinifolium ethanolic extracts was studied in vitro on Gram-positive and Gram-negative bacteria, yeasts and fungi. The cytotoxicity of the extracts was also evaluated using the Artemia salina test. All the extracts showed antimicrobial activity in a range of concentrations between 10 and 650 microgml of dry extract. E. angustifolium and E. rosmarinifolium had the most broad spectrum of action inhibiting bacteria, yeasts and fungi. The extracts were devoid of toxicity on Artemia salina within the range of antimicrobial concentrations, suggesting that the action is selective on microorganisms. PMID:11482755

  3. Companion-Cell Specific Localization of Sucrose Synthase in Zones of Phloem Loading and Unloading

    Microsoft Academic Search

    Kurt D. Nolte; Karen E. Koch

    An immunohistochemical approach was used in maize (Zea mays) and citrus (Cifrus paradisi) to address the previously noted association between sucrose synthase and vascular bundles and to determine the localization of the low but detectable levels of sucrose synthase that remain in leaves after the import-export transition. Sucrose synthase protein was immunolocalized at the light microscope leve1 using paraffin sections

  4. SUGARBEET ROOT SUCROSE SYNTHASE ISOFORMS DIFFER IN DEVELOPMENTAL EXPRESSION, SUBUNIT COMPOSITION AND RESPONSE TO PH.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two sucrose synthase isoforms have been identified by activity stained isoelectric focused polyacrylamide electrophoresis in developing sugarbeet (Beta vulgaris L.) root. Sucrose synthase isoform I (SuSyI) was present from the early stages of development to maturity. Sucrose synthase isoform II (S...

  5. Aspects of sucrose transport in stem parenchyma of sweet sorghum. [Sorghum bicolor

    SciTech Connect

    Lingle, S.E.

    1987-08-01

    Sweet sorghum (Sorghum bicolor (L.) Moench) is a sucrose-storing crop with a storage tissue anatomically similar to that of sugarcane (Saccharum spp.). However, recent evidence suggests that sweet sorghum may be biochemically different from sugarcane. /sup 14/C-sucrose uptake was studied in excised tissue discs from fully-elongated internodes of Rio sweet sorghum. Washout studies gave results consistent with a 3 compartment system. After 3 hours of uptake, most of the /sup 14/C was found in the vacuole compartment, and was determined by HPLC to be sucrose. Total sucrose uptake consisted of a PCMBS-sensitive (active) and a PCMBS-insensitive (passive) component. Active sucrose uptake had a pH optimum of 4.5. Total sucrose uptake was negatively correlated with the internal sucrose content of the tissue. Fructosyl-labelled /sup 14/C-sucrose was not randomized during uptake, suggesting that sucrose cleavage is not a requirement for sucrose uptake in sweet sorghum. This data suggests that in sweet sorghum, sucrose is transported intact by a specific carrier, as opposed to the sucrose-cleavage-and-resynthesis transport system that apparently operates in sugarcane.

  6. Fructo-oligosaccharides production by the Gluconacetobacter diazotrophicus levansucrase expressed in the methylotrophic yeast Pichia pastoris.

    PubMed

    Trujillo, L E.; Arrieta, J G.; Dafhnis, F; García, J; Valdés, J; Tambara, Y; Pérez, M; Hernández, L

    2001-02-01

    Levansucrase (LsdA) (EC 2.4.1.10) from Gluconacetobacter diazotrophicus (formerly Acetobacter diazotrophicus) yields high levels of fructo-oligosaccharides (FOS) from sucrose. A DNA fragment encoding the precursor LsdA lacking the first 57 amino acids was fused to the pho1 signal sequence under the control of the Pichia pastoris-alcohol oxidase 1 (AOX1) promoter. Methanol induction of a P. pastoris strain harboring a single copy of the lsdA expression cassette integrated in the genome resulted in the production of active levansucrase. After fermentation of the recombinant yeast, LsdA activity was detected in the periplasmic fraction (81%) and in the culture supernatant (18%) with an overall yield of 1% of total protein. The recombinant LsdA was glycosylated and displayed optimal pH and temperature for enzyme activity similar to those of the native enzyme, but thermal stability was increased. Neither fructosylpolymerase activity nor FOS production was affected. Incubation of recombinant LsdA in sucrose (500 g l(-1)) yielded 43% (w/w) of total sugar as 1-kestose, with a conversion efficiency about 70%. Intact recombinant yeast cells also converted sucrose to FOS although for a 30% efficiency. PMID:11166804

  7. The genetics of a putative social trait in natural populations of yeast.

    PubMed

    Bozdag, G O; Greig, D

    2014-10-01

    The sharing of secreted invertase by yeast cells is a well-established laboratory model for cooperation, but the only evidence that such cooperation occurs in nature is that the SUC loci, which encode invertase, vary in number and functionality. Genotypes that do not produce invertase can act as 'cheats' in laboratory experiments, growing on the glucose that is released when invertase producers, or 'cooperators', digest sucrose. However, genetic variation for invertase production might instead be explained by adaptation of different populations to different local availabilities of sucrose, the substrate for invertase. Here we find that 110 wild yeast strains isolated from natural habitats, and all contained a single SUC locus and produced invertase; none were 'cheats'. The only genetic variants we found were three strains isolated instead from sucrose-rich nectar, which produced higher levels of invertase from three additional SUC loci at their subtelomeres. We argue that the pattern of SUC gene variation is better explained by local adaptation than by social conflict. PMID:25169714

  8. The genetics of a putative social trait in natural populations of yeast

    PubMed Central

    Bozdag, G O; Greig, D

    2014-01-01

    The sharing of secreted invertase by yeast cells is a well-established laboratory model for cooperation, but the only evidence that such cooperation occurs in nature is that the SUC loci, which encode invertase, vary in number and functionality. Genotypes that do not produce invertase can act as ‘cheats’ in laboratory experiments, growing on the glucose that is released when invertase producers, or ‘cooperators’, digest sucrose. However, genetic variation for invertase production might instead be explained by adaptation of different populations to different local availabilities of sucrose, the substrate for invertase. Here we find that 110 wild yeast strains isolated from natural habitats, and all contained a single SUC locus and produced invertase; none were ‘cheats’. The only genetic variants we found were three strains isolated instead from sucrose-rich nectar, which produced higher levels of invertase from three additional SUC loci at their subtelomeres. We argue that the pattern of SUC gene variation is better explained by local adaptation than by social conflict. PMID:25169714

  9. Cystationine synthesis in yeast: an alternative pathway for homocysteine biosynthesis.

    PubMed

    Savin, M A; Flavin, M

    1972-10-01

    Cystathionine synthesis from O-acetylhomoserine and cysteine has been demonstrated in yeast extracts for the first time. The activity is less than that of O-acetylhomoserine sulfhydrylase, but it is higher than that reported for homoserine O-transacetylase and therefore should not be growth limiting. Cystathionine synthase seems to share the regulatory properties of the sulfhydrylase, and both activities are missing from the methionine auxotroph Saccharomyces cerevisiae EY9, suggesting that both reactions are catalyzed by the same enzyme. However, cystathionine synthase activity was lost during purification of the sulfhydrylase, suggesting that the two reactions may be catalyzed by separate enzymes. Since previous studies have shown that yeast extracts can catalyze the cleavage of cystathionine to homocysteine, our results show the existence of two complete alternate pathways for homocysteine biosynthesis in yeast. Which of these is the major physiological pathway remains to be determined. PMID:4263404

  10. Antioxidant activities and anticancer effects of red yeast rice grown in the medium containing garlic

    Microsoft Academic Search

    Hye-Jin Park; In-Sook Kim

    2011-01-01

    The effects of culture time on antioxidant and anticancer activities of red yeast rice-garlic (RYRG) ethanol extracts were\\u000a investigated. RYRG is a product of red yeast rice (Monascus pilosus) grown in medium containing garlic for 0, 2, 4, 6, and 8 weeks. The total phenolic and total flavonoid contents of RYRG extracts\\u000a were increasing with the length of culture periods.

  11. New phenylpropanoid esters of sucrose from Polygonum hydropiper and their antioxidant activity.

    PubMed

    Kiem, Phan Van; Nhiem, Nguyen Xuan; Cuong, Nguyen Xuan; Hoa, Tran Quynh; Huong, Hoang Thanh; Huong, Le Mai; Minh, Chau Van; Kim, Young Ho

    2008-11-01

    By various chromatographic methods, two new phenylpropanoid esters of sucrose named hidropiperosides A (1) and B (2), and three known compounds as vanicosides A (3), B (4), and E (5) were isolated from the methanolic extract of the whole plant of Polygonum hydropiper L. (Polygonaceae). Their structures were elucidated by extensive spectroscopic methods including 1D-and 2D-NMR experiments, as well as ESI-MS analysis. All the isolated compounds were tested for their antioxidant activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay system. Among them, compounds 2 and 3 showed significant antioxidant activity with their SC(50) values of 23.4 and 26.7 microg/mL, respectively. PMID:19023545

  12. Genome evolution in yeasts

    Microsoft Academic Search

    Bernard Dujon; David Sherman; Gilles Fischer; Pascal Durrens; Serge Casaregola; Ingrid Lafontaine; Jacky de Montigny; Christian Marck; Cécile Neuvéglise; Emmanuel Talla; Nicolas Goffard; Lionel Frangeul; Michel Aigle; Véronique Anthouard; Anna Babour; Valérie Barbe; Stéphanie Barnay; Sylvie Blanchin; Jean-Marie Beckerich; Emmanuelle Beyne; Claudine Bleykasten; Anita Boisramé; Jeanne Boyer; Laurence Cattolico; Fabrice Confanioleri; Antoine de Daruvar; Laurence Despons; Emmanuelle Fabre; Cécile Fairhead; Hélène Ferry-Dumazet; Alexis Groppi; Florence Hantraye; Christophe Hennequin; Nicolas Jauniaux; Philippe Joyet; Rym Kachouri; Alix Kerrest; Romain Koszul; Marc Lemaire; Isabelle Lesur; Laurence Ma; Héloïse Muller; Jean-Marc Nicaud; Macha Nikolski; Sophie Oztas; Odile Ozier-Kalogeropoulos; Stefan Pellenz; Serge Potier; Guy-Franck Richard; Marie-Laure Straub; Audrey Suleau; Dominique Swennen; Fredj Tekaia; Micheline Wésolowski-Louvel; Eric Westhof; Bénédicte Wirth; Maria Zeniou-Meyer; Ivan Zivanovic; Monique Bolotin-Fukuhara; Agnès Thierry; Christiane Bouchier; Bernard Caudron; Claude Scarpelli; Claude Gaillardin; Jean Weissenbach; Patrick Wincker; Jean-Luc Souciet

    2004-01-01

    Identifying the mechanisms of eukaryotic genome evolution by comparative genomics is often complicated by the multiplicity of events that have taken place throughout the history of individual lineages, leaving only distorted and superimposed traces in the genome of each living organism. The hemiascomycete yeasts, with their compact genomes, similar lifestyle and distinct sexual and physiological properties, provide a unique opportunity

  13. METHODS TO IDENTIFY YEAST

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yeasts are commonly identified from either phenotype or, more recently, from diagnostic gene sequences. Methods based on phenotype include fermentation reactions on a select set of sugars and growth responses on various carbon and nitrogen sources or on other diagnostic compounds. Isolates are fur...

  14. Opportunistic Pathogenic Yeasts

    NASA Astrophysics Data System (ADS)

    Banerjee, Uma

    Advances in medical research, made during the last few decades, have improved the prophylactic, diagnostic and therapeutic capabilities for variety of infections/diseases. However, many of the prophylactic and therapeutic procedures have been seen in many instances to exact a price of host-vulnerability to an expanding group of opportunistic pathogens and yeasts are one of the important members in it. Fortunately amongst the vast majority of yeasts present in nature only few are considered to have the capability to cause infections when certain opportunities predisposes and these are termed as ‘opportunistic pathogenic yeasts.’ However, the term ‘pathogenic’ is quite tricky, as it depends of various factors of the host, the ‘bug’ and the environment to manifest the clinical infection. The borderline is expanding. In the present century with unprecedented increase in number of immune-compromised host in various disciplines of health care settings, where any yeast, which has the capability to grow at 37 ° C (normal body temperature of human), can be pathogenic and cause infection in particular situation

  15. Stimulatory effects of 2,4-dichlorophenoxyacetic acid and of 1-naphthylacetic acid on sucrose level, invertase activity and sucrose utilization in the latex of Hevea brasiliensis

    Microsoft Academic Search

    Jaroslav Tupý

    1969-01-01

    Summary Treatment of the bark ofHevea brasiliensis with 2,4-dichlorophenoxyacetic acid (2,4-D) or l-naphthylacetic acid (NAA) greatly increases sucrose level, invertase activity and sucrose utilization in the latex; the efficacy of 2,4-D is considerably greater than that of NAA. The greater sucrose utilization is the consequence of increased invertase activity. The changes occur as soon as the first tapping following bark

  16. Flavour-active wine yeasts.

    PubMed

    Cordente, Antonio G; Curtin, Christopher D; Varela, Cristian; Pretorius, Isak S

    2012-11-01

    The flavour of fermented beverages such as beer, cider, saké and wine owe much to the primary fermentation yeast used in their production, Saccharomyces cerevisiae. Where once the role of yeast in fermented beverage flavour was thought to be limited to a small number of volatile esters and higher alcohols, the discovery that wine yeast release highly potent sulfur compounds from non-volatile precursors found in grapes has driven researchers to look more closely at how choice of yeast can influence wine style. This review explores recent progress towards understanding the range of 'flavour phenotypes' that wine yeast exhibit, and how this knowledge has been used to develop novel flavour-active yeasts. In addition, emerging opportunities to augment these phenotypes by engineering yeast to produce so-called grape varietal compounds, such as monoterpenoids, will be discussed. PMID:22940803

  17. The Regulation of Filamentous Growth in Yeast

    PubMed Central

    Cullen, Paul J.; Sprague, George F.

    2012-01-01

    Filamentous growth is a nutrient-regulated growth response that occurs in many fungal species. In pathogens, filamentous growth is critical for host–cell attachment, invasion into tissues, and virulence. The budding yeast Saccharomyces cerevisiae undergoes filamentous growth, which provides a genetically tractable system to study the molecular basis of the response. Filamentous growth is regulated by evolutionarily conserved signaling pathways. One of these pathways is a mitogen activated protein kinase (MAPK) pathway. A remarkable feature of the filamentous growth MAPK pathway is that it is composed of factors that also function in other pathways. An intriguing challenge therefore has been to understand how pathways that share components establish and maintain their identity. Other canonical signaling pathways—rat sarcoma/protein kinase A (RAS/PKA), sucrose nonfermentable (SNF), and target of rapamycin (TOR)—also regulate filamentous growth, which raises the question of how signals from multiple pathways become integrated into a coordinated response. Together, these pathways regulate cell differentiation to the filamentous type, which is characterized by changes in cell adhesion, cell polarity, and cell shape. How these changes are accomplished is also discussed. High-throughput genomics approaches have recently uncovered new connections to filamentous growth regulation. These connections suggest that filamentous growth is a more complex and globally regulated behavior than is currently appreciated, which may help to pave the way for future investigations into this eukaryotic cell differentiation behavior. PMID:22219507

  18. Yeasts associated with Manteca.

    PubMed

    Suzzi, Giovanna; Schirone, Maria; Martuscelli, Maria; Gatti, Monica; Fornasari, Maria Emanuela; Neviani, Erasmo

    2003-04-01

    Manteca is a traditional milk product of southern Italy produced from whey deriving from Caciocavallo Podolico cheese-making. This study was undertaken to obtain more information about the microbiological properties of this product and particularly about the presence, metabolic activities, and technological significance of the different yeast species naturally occurring in Manteca. High numbers of yeasts were counted after 7 days ripening (10(4)-10(5) cfu g(-1)) and then decreased to 10(2) at the end. A total of 179 isolates were identified and studied for their phenotypic and genotypic characteristics. The most frequently encountered species were Trichosporon asahii (45), Candida parapsilosis (33), Rhodotorula mucilaginosa (32), Candida inconspicua (29). Some of these yeasts showed lipolytic activity (32 strains) and proteolytic activity (29 strains), NaCl resistance up to 10% and growth up to 45 degrees C (42 strains). Biogenic amines were formed by proteolytic strains, in particular phenylethylamine, putrescine and spermidine. Spermidine was produced by all the yeasts tested in this work, but only Trichosporon produced a great quantity of this compound. Histamine was not detectable. Caseinolytic activity was common to almost all strains, corresponding to the ability to efficiently split off amino-terminal amino acids. The highest and most constant activity expressed by all species was X-prolyl-dipeptidyl aminopeptidase. The findings suggest that the presence of yeasts may play a significant role in justifying interactions with lactic acid bacteria, and consequently with their metabolic activity in the definition of the peculiar characteristics of Manteca cheese. PMID:12702448

  19. Calcium-mediated conversion of sucrose to starch in relation to the activities of amylases and sucrose-metabolizing enzymes in sorghum grains raised through liquid culture.

    PubMed

    Bhatia, S; Singh, R

    2000-04-01

    Detached ears of sorghum (Sorghum vulgare) were cultured in complete liquid medium containing Ca2+(0, 3, 10 and 30 mM) and effect of this ion on the conversion of sucrose to starch with respect to the activities of amylases, sucrose synthase, sucrose phosphate synthase and soluble invertases were studied in developing grains. Presence of 3 mM Ca2+ in culture medium enhanced both accumulation of starch and activity of alpha-amylase in grain but without having any influence on the activity of beta-amylase. However, with 10 and 30 mM Ca2+, the accumulation of starch and activities of both amylases decreased and with advancement in culturing period, starch accumulation was further decreased. Irrespective of its concentration, Ca2+ enhanced the activities of sucrose synthase (synthesis), sucrose-phosphate synthase, soluble acid invertase and soluble-neutral invertase. Increase in the concentration of Ca2+ in culture medium was concomitant with an elevation in relative proportion of sucrose in the grain reflecting a net balance in per cent increase with Ca2+ in the activities of sucrose-synthesizing enzymes over sucrose-hydrolysing ones. Based on the results, it is suggested that assimilation of Ca2+ by grain is essential for maintaining high activity of alpha-amylase to generate starch primers required for the conversion of sucrose to starch during grain filling in sorghum. PMID:10983425

  20. Oxidation Reduction Potential of Complex Iron Compounds in Yeast

    Microsoft Academic Search

    Thomas B. Coolidge

    1931-01-01

    WHEN an alkaline extract of yeast is saturated with ammonium sulphate there is precipitated, with the protein, cytochrome `C' and a complex iron compound giving no visible spectrum. The latter can be separated from the proteins slowly by ultra-filtration. It remains in solution when the protein, with the cytochrome `C', is precipitated by trichloracetic acid.

  1. Immunoprecipitation and Characterization of Membrane Protein Complexes from Yeast

    ERIC Educational Resources Information Center

    Parra-Belky, Karlett; McCulloch, Kathryn; Wick, Nicole; Shircliff, Rebecca; Croft, Nicolas; Margalef, Katrina; Brown, Jamie; Crabill, Todd; Jankord, Ryan; Waldo, Eric

    2005-01-01

    In this undergraduate biochemistry laboratory experiment, the vacuolar ATPase protein complex is purified from yeast cell extracts by doing immunoprecipitations under nondenaturing conditions. Immunoprecipitations are performed using monoclonal antibodies to facilitate data interpretation, and subunits are separated on the basis of their molecular…

  2. Global expression studies in baker's yeast reveal target genes for the improvement of industrially-relevant traits: the cases of CAF16 and ORC2

    PubMed Central

    2010-01-01

    Background Recent years have seen a huge growth in the market of industrial yeasts with the need for strains affording better performance or to be used in new applications. Stress tolerance of commercial Saccharomyces cerevisiae yeasts is, without doubt, a trait that needs improving. Such trait is, however, complex, and therefore only in-depth knowledge of their biochemical, physiological and genetic principles can help us to define improvement strategies and to identify the key factors for strain selection. Results We have determined the transcriptional response of commercial baker's yeast cells to both high-sucrose and lean dough by using DNA macroarrays and liquid dough (LD) model system. Cells from compressed yeast blocks display a reciprocal transcription program to that commonly reported for laboratory strains exposed to osmotic stress. This discrepancy likely reflects differences in strain background and/or experimental design. Quite remarkably, we also found that the transcriptional response of starved baker's yeast cells was qualitatively similar in the presence or absence of sucrose in the LD. Nevertheless, there was a set of differentially regulated genes, which might be relevant for cells to adapt to high osmolarity. Consistent with this, overexpression of CAF16 or ORC2, two transcriptional factor-encoding genes included in this group, had positive effects on leavening activity of baker's yeast. Moreover, these effects were more pronounced during freezing and frozen storage of high-sucrose LD. Conclusions Engineering of differentially regulated genes opens the possibility to improve the physiological behavior of baker's yeast cells under stress conditions like those encountered in downstream applications. PMID:20626860

  3. A new colorimetric method for determining the isomerization activity of sucrose isomerase.

    PubMed

    Park, Sang-Eun; Cho, Mee-Hyun; Lim, Jin Kyu; Kim, Jong-Sang; Kim, Jeong Hwan; Kwon, Dae Young; Park, Cheon-Seok

    2007-02-01

    A new colorimetric method for determining the isomerization activity of sucrose isomerase was developed. This colorimetric method is based on the enzymatic reactions of invertase and glucose oxidase-peroxidase (GOD-POD). The main scheme for assaying sucrose isomerase activity is to degrade sucrose in the reaction mixture to glucose and fructose by invertase and to detect the concentration of glucose generated using GOD-POD. The concentrations of trehalulose and isomaltulose, reaction products of sucrose isomerase, are calculated from the concentration of glucose. This method allows rapid and accurate determination of the isomerization activity of sucrose isomerase without inhibition by hydrolysis activity. PMID:17284828

  4. Sucrose monoester micelles size determined by Fluorescence Correlation Spectroscopy (FCS).

    PubMed

    Sanchez, Susana A; Gratton, Enrico; Zanocco, Antonio L; Lemp, Else; Gunther, German

    2011-01-01

    One of the several uses of sucrose detergents, as well as other micelle forming detergents, is the solubilization of different membrane proteins. Accurate knowledge of the micelle properties, including size and shape, are needed to optimize the surfactant conditions for protein purification and membrane characterization. We synthesized sucrose esters having different numbers of methylene subunits on the substituent to correlate the number of methylene groups with the size of the corresponding micelles. We used Fluorescence Correlation Spectroscopy (FCS) and two photon excitation to determine the translational D of the micelles and calculate their corresponding hydrodynamic radius, R(h). As a fluorescent probe we used LAURDAN (6-dodecanoyl-2-dimethylaminonaphthalene), a dye highly fluorescent when integrated in the micelle and non-fluorescent in aqueous media. We found a linear correlation between the size of the tail and the hydrodynamic radius of the micelle for the series of detergents measured. PMID:22216230

  5. Effect of dietary copper and sucrose on catecholamine concentrations in the adrenal medulla

    SciTech Connect

    Koo, S.I.; Peterson, D.F.; Mason, P.A. (Kansas State Univ., Manhattan (United States) KCOM, Kirksville, MO (United States) Air Force/SAM/RZP, Brooks AFB, TX (United States))

    1991-03-11

    The severity of copper (Cu) deficiency in the rat is enhanced by dietary sucrose. Possible interactive effects of Cu status and sucrose on catecholamine concentrations in the adrenal medulla were investigated in Cu deficient rats fed a diet were investigated in Cu deficient rats fed a diet containing either glucose or sucrose, as compared with respective Cu-adequate controls. Catecholamines were analyzed by an HPLC method using 3,4-dihydroxybenxylamine as the internal standard. Cu deficiency caused pronounced decreases in norepinephrine and epinephrine, with no significant effect on dopamine, as expressed in nmoles/mg tissue. Dietary sucrose showed no appreciable effect on catecholamines in the adrenal medulla. The adrenal glands were markedly enlarged in Cu-deficient rats, whether fed glucose or sucrose. Adrenal weights were not affected by dietary sucrose. Data indicate that the increased severity of copper deficiency due to sucrose feeding is not associated with changes in adrenal catecholamine output.

  6. Steroid hormone excretion is enhanced by sucrose feeding to rats

    SciTech Connect

    Kruger, T.C.; Hsu, H.; Saunders, J.P.; Kim, S.S.; Given-Proctor, J.; Ahrens, R.A.

    1986-03-01

    The hypothesis tested was that feeding rats sucrose rather than invert sugar (50:50 mixture of glucose and fructose) or cornstarch would result in a more rapid excretion of intravenously injected 1,2-/sup 3/H aldosterone or 1,2,6,7-/sup 3/H cortisol. The three carbohydrate sources provided 45% of dietary energy when fed, respectively, to one of three groups of 10 male, Sprague Dawley rats. After 4 or 8 weeks of ad lib feeding of the three diets 5 ..mu..CI of /sup 3/H-labeled hormones were injected intravenously and % recovery in urine and feces was measured for 4 days by liquid scintillation counting. Nearly 90% of the /sup 3/H injected as 1,2-/sup 3/H aldosterone was recovered over 4 days in the excreta of the sucrose fed rats. This recovery of /sup 3/H from aldosterone was significantly greater (P < 0.01) than when invert sugar (65%) or cornstarch (60%) were fed. The recovery of /sup 3/H from intravenously injected 1,2,6,7-/sup 3/H cortisol followed a similar pattern. The authors anticipate that the excretion of all metabolic end products and xenobiotics excreted as glucuronides would be enhanced by sucrose feeding. Oxocarbonium ions from the glucose portion of sucrose digestion in the mammalian small intestine are thought to compete with oxocarbonium ions from the glucuronic acid portion of glucuronide hydrolysis. Such competition may slow glucuronide hydrolysis and promote glucuronide excretion, including the glucuronides derived from aldosterone and cortisol.

  7. Glass Transition and Crystallization of Amorphous Trehalose-sucrose Mixtures

    Microsoft Academic Search

    K. D. Roe; T. P. Labuza

    2005-01-01

    Our objective was to investigate the glass transition and crystallization of trehalose-sucrose mixtures at various moisture contents. Samples were freeze-dried, rehumidified, and scanned with Differential scanning calorimetry (DSC) to obtain Tg values for all mixtures and pure sugars. Amorphous cotton candy samples for crystallization studies were prepared, humidified, and monitored for crystallinity as a function of time using powder X-ray

  8. Effect of sucrose on the metabolic disposition of aspartame13

    Microsoft Academic Search

    Lewis D Stegink; Marvin C Brummel; Thomas J Persoon; Lloyd J Filer; Edward F Bell Jr; Ekhard E Ziegler

    Twelve normal adult subjects ingested a bev- erage providing 0. 136 mmol aspartame\\/kg body wt on 2 different days. On 1 study day the beverage provided only aspartame, on the other the beverage provided both aspartame and 3.5 1 mmol sucrose\\/kg body wt. The high mean plasma phenylabanine concentrations were similar after administra- tion of aspartame alone (158 ± 28.9

  9. Central Melanocortins Regulate the Motivation for Sucrose Reward

    PubMed Central

    Pandit, Rahul; van der Zwaal, Esther M.; Luijendijk, Mieneke C. M.; Brans, Maike A. D.; van Rozen, Andrea J.; Oude Ophuis, Ralph J. A.; Vanderschuren, Louk J. M. J.

    2015-01-01

    The role of the melanocortin (MC) system in feeding behavior is well established. Food intake is potently suppressed by central infusion of the MC 3/4 receptor agonist ?-melanocyte stimulating hormone (?-MSH), whereas the MC 3/4 receptor inverse-agonist Agouti Related Peptide (AGRP) has the opposite effect. MC receptors are widely expressed in both hypothalamic and extra-hypothalamic brain regions, including nuclei involved in food reward and motivation, such as the nucleus accumbens (NAc) and the ventral tegmental area. This suggests that MCs modulate motivational aspects of food intake. To test this hypothesis, rats were injected intracerebroventricularly with ?-MSH or AGRP and their motivation for sucrose was tested under a progressive ratio schedule of reinforcement. Food motivated behavior was dose-dependently decreased by ?-MSH. Conversely, AGRP increased responding for sucrose, an effect that was blocked by pretreatment with the dopamine receptor antagonist ?-flupenthixol. In contrast to progressive ratio responding, free intake of sucrose remained unaltered upon ?-MSH or AGRP infusion. In addition, we investigated whether the effects of ?-MSH and AGRP on food motivation were mediated by the NAc shell. In situ hybridization of MC3 and MC4 receptor expression confirmed that the MC4 receptor was expressed throughout the NAc, and injection of ?-MSH and AGRP into the NAc shell caused a decrease and an increase in motivation for sucrose, respectively. These data show that the motivation for palatable food is modulated by MC4 receptors in the NAc shell, and demonstrate cross-talk between the MC and dopamine system in the modulation of food motivation. PMID:25811380

  10. Yeast and Mammalian Metallothioneins Functionally Substitute for Yeast Copper-Zinc Superoxide Dismutase

    NASA Astrophysics Data System (ADS)

    Tamai, Katherine T.; Gralla, Edith B.; Ellerby, Lisa M.; Valentine, Joan S.; Thiele, Dennis J.

    1993-09-01

    Copper-zinc superoxide dismutase catalyzes the disproportionation of superoxide anion to hydrogen peroxide and dioxygen and is thought to play an important role in protecting cells from oxygen toxicity. Saccharomyces cerevisiae strains lacking copper-zinc superoxide dismutase, which is encoded by the SOD1 gene, are sensitive to oxidative stress and exhibit a variety of growth defects including hypersensitivity to dioxygen and to superoxide-generating drugs such as paraquat. We have found that in addition to these known phenotypes, SOD1-deletion strains fail to grow on agar containing the respiratory carbon source lactate. We demonstrate here that expression of the yeast or monkey metallothionein proteins in the presence of copper suppresses the lactate growth defect and some other phenotypes associated with SOD1-deletion strains, indicating that copper metallothioneins substitute for copper-zinc superoxide dismutase in vivo to protect cells from oxygen toxicity. Consistent with these results, we show that yeast metallothionein mRNA levels are dramatically elevated under conditions of oxidative stress. Furthermore, in vitro assays demonstrate that yeast metallothionein, purified or from whole-cell extracts, exhibits copper-dependent antioxidant activity. Taken together, these data suggest that both yeast and mammalian metallothioneins may play a direct role in the cellular defense against oxidative stress by functioning as antioxidants.

  11. Accumulation of Phosphate, Sulfate and Sucrose by Excised Phloem Tissues

    PubMed Central

    Bieleski, R. L.

    1966-01-01

    Excised petiolar vascular bundles and excised phloem tissues have been shown to take up phosphate, sulfate and sucrose by a true accumulation process and against high concentration ratios. Phosphate was accumulated principally as inorganic phosphate, and sucrose principally as sucrose. The rates of accumulation of the 3 solutes into the phloem-containing tissues were from 4 to 35 times higher than into comparable parenchyma tissue. It is suggested that this active accumulation mechanism plays an important role in the phenomenon of phloem transport. The excised vascular, phloem and parenchyma tissues show an aging phenomenon: aerating the excised tissues for 18 hours prior to their use causes marked changes in the accumulatory behavior of the tissue. The data suggest that 1 phosphate accumulation system of low affinity but high capacity exists in fresh tissue, and that aging allows the development of a second, additional phosphate accumulation mechanism of high affinity and low capacity. A possible role in the control of phosphate movement is suggested. PMID:16656275

  12. Extracellular Polysaccharides Produced by Yeasts and Yeast-Like Fungi

    NASA Astrophysics Data System (ADS)

    van Bogaert, Inge N. A.; de Maeseneire, Sofie L.; Vandamme, Erick J.

    Several yeasts and yeast-like fungi are known to produce extracellular polysaccharides. Most of these contain D-mannose, either alone or in combination with other sugars or phosphate. A large chemical and structural variability is found between yeast species and even among different strains. The types of polymers that are synthesized can be chemically characterized as mannans, glucans, phosphoman-nans, galactomannans, glucomannans and glucuronoxylomannans. Despite these differences, almost all of the yeast exopolysaccharides display some sort of biological activity. Some of them have already applications in chemistry, pharmacy, cosmetics or as probiotic. Furthermore, some yeast exopolysaccharides, such as pullulan, exhibit specific physico-chemical and rheological properties, making them useful in a wide range of technical applications. A survey is given here of the production, the characteristics and the application potential of currently well studied yeast extracellular polysaccharides.

  13. Persisting adiposity following chronic consumption of 10% sucrose solution: strain differences and behavioural effects.

    PubMed

    Kendig, Michael D; Rooney, Kieron B; Corbit, Laura H; Boakes, Robert A

    2014-05-10

    The metabolic consequences of providing rats with extended access to sugar solutions have varied across studies. The two experiments in this study examined the effects of 8 weeks of 24-h access to 10% sucrose solution on adult Wistar rats. This was followed by 6 weeks of food restriction with no access to sucrose during which the behavioural effects of prior sucrose consumption on reward-oriented behaviour (Experiment 1) and reversal learning (Experiment 2) were assessed. In a comparison between rat strains, Experiment 1 found that sucrose accelerated weight gain in Albino but not Hooded Wistar rats, while sucrose-fed rats of both strains exhibited elevated fasting blood glucose and resistance to insulin. Importantly, at cull retroperitoneal fat deposits were elevated in sucrose-fed rats, at which point glucose and insulin had resolved to control levels and liver triglyceride content did not differ between groups. Experiment 2 also found that retroperitoneal fat content was higher in sucrose-fed rats at cull, after 6 weeks of behavioural testing without sucrose and with restricted access to food, and found a similar effect for epididymal fat. Behavioural testing in Experiment 1 found that sucrose exposure had no effect on habit formation assessed using an outcome devaluation paradigm. However, instrumental responding by sucrose-fed Albino rats was the least affected by pre-feeding, indicating a relationship between sucrose-induced obesity and food-seeking behaviour. In Experiment 2, sucrose-fed and control rats did not differ on a discrimination reversal task. In conclusion, this study demonstrates that the behavioural and metabolic effects of sucrose consumption vary with strain. Further, results indicate that sucrose consumption can lead to lasting increases in adipose tissue stores, a finding which has significant implications for human diets. PMID:24662698

  14. ''Is Yeast Alive?''

    NSDL National Science Digital Library

    Ms. Katrenia Hosea-Flanigan (Frank Cody High School)

    2006-04-01

    In this inquiry activity students explore the characteristics of living organisms to determine whether yeast meets the criteria of a living thing. This inquiry activity was developed by a K-12 science teacher in the American Physiological SocietyÂ?s 2006 Frontiers in Physiology Program. The NSES Standards addressed by this activity are current as of the year of development. For more information on the Frontiers in Physiology Program, please visit www.frontiersinphys.org.

  15. Transforming a fructan:fructan 6G-fructosyltransferase from perennial ryegrass into a sucrose:sucrose 1-fructosyltransferase.

    PubMed

    Lasseur, Bertrand; Schroeven, Lindsey; Lammens, Willem; Le Roy, Katrien; Spangenberg, German; Manduzio, Hélène; Vergauwen, Rudy; Lothier, Jérémy; Prud'homme, Marie-Pascale; Van den Ende, Wim

    2009-01-01

    Fructosyltransferases (FTs) synthesize fructans, fructose polymers accumulating in economically important cool-season grasses and cereals. FTs might be crucial for plant survival under stress conditions in species in which fructans represent the major form of reserve carbohydrate, such as perennial ryegrass (Lolium perenne). Two FT types can be distinguished: those using sucrose (S-type enzymes: sucrose:sucrose 1-fructosyltransferase [1-SST], sucrose:fructan 6-fructosyltransferase) and those using fructans (F-type enzymes: fructan:fructan 1-fructosyltransferase [1-FFT], fructan:fructan 6G-fructosyltransferase [6G-FFT]) as preferential donor substrate. Here, we report, to our knowledge for the first time, the transformation of an F-type enzyme (6G-FFT/1-FFT) into an S-type enzyme (1-SST) using perennial ryegrass 6G-FFT/1-FFT (Lp6G-FFT/1-FFT) and 1-SST (Lp1-SST) as model enzymes. This transformation was accomplished by mutating three amino acids (N340D, W343R, and S415N) in the vicinity of the active site of Lp6G-FFT/1-FFT. In addition, effects of each amino acid mutation alone or in combination have been studied. Our results strongly suggest that the amino acid at position 343 (tryptophan or arginine) can greatly determine the donor substrate characteristics by influencing the position of the amino acid at position 340. Moreover, the presence of arginine-343 negatively affects the formation of neofructan-type linkages. The results are compared with recent findings on donor substrate selectivity within the group of plant cell wall invertases and fructan exohydrolases. Taken together, these insights contribute to our knowledge of structure/function relationships within plant family 32 glycosyl hydrolases and open the way to the production of tailor-made fructans on a larger scale. PMID:18952861

  16. Sucrose is metabolised by sucrose synthase and glycolysis within the phloem complex of Ricinus communis L. seedlings

    Microsoft Academic Search

    Peter Geigenberger; Silke Langenberger; Ingo Wilke; Dieter Heineke; Hans W. Heldt; Mark Stitt

    1993-01-01

    Metabolites and enzyme activities were measured in the phloem sap exuding from a cut hypocotyl of germinating castor-bean (Ricinus communis L.) seedlings. The sap contained considerable quantities of adenine nucleotides, uridine nucleotides, uridine diphosphoglucose (UDPGlc), all the major phosphorylated metabolites required for glycolysis, fructose-2,6-bisphosphate and pyrophosphate. Supplying 200 mM glucose instead of sucrose to the cotyledons resulted in high concentrations

  17. Antisense Inhibition of Tomato Fruit Sucrose Synthase Decreases Fruit Setting and the Sucrose Unloading Capacity of Young Fruit

    Microsoft Academic Search

    Marc-André D'Aoust; Serge Yelle; Binh Nguyen-Quoc

    1999-01-01

    The role of sucrose synthase (SuSy) in tomato fruit was studied in transgenic tomato ( Lycopersicon esculentum ) plants expressing an antisense fragment of fruit-specific SuSy RNA ( TOMSSF ) under the control of the cauliflower mosaic vi- rus 35S promoter. Constitutive expression of the antisense RNA markedly inhibited SuSy activity in flowers and fruit pericarp tissues. However, inhibition was

  18. Emerging opportunistic yeast infections.

    PubMed

    Miceli, Marisa H; Díaz, José A; Lee, Samuel A

    2011-02-01

    A growing population of immunosuppressed patients has resulted in increasingly frequent diagnoses of invasive fungal infections, including those caused by unusual yeasts. The incidence of non-albicans species of Candida is increasing compared with that of Candida albicans, and several species, such as Candida glabrata and Candida krusei, may be resistant to azole antifungal therapy. Trichosporon species are the second most common cause of fungaemia in patients with haematological malignant disease and are characterised by resistance to amphotericin and echinocandins and poor prognosis. Rhodotorula species belong to the family Cryptococcaceae, and are a cause of catheter-related fungaemia, sepsis, and invasive disease in severely immunosuppressed patients. An increasing number of sporadic cases of invasive fungal infections by non-neoformans cryptococci have been reported in immunocompromised hosts, especially for patients with advanced HIV infection or cancer who are undergoing transplant. Other uncommon yeasts that can cause invasive disease in severely immunosuppressed patients include Geotrichum, Hansenula, Malassezia, and Saccharomyces. Host immune status is a crucial determinant of the type of invasive fungal infection a patient is at risk for. Diagnosis can be challenging and relies heavily on traditional cultures of blood and other sterile sites, although serum (1,3)-?-D-glucan testing might have an adjunctive role. Although rare yeasts are emerging as opportunistic human pathogens, diagnosis remains challenging and treatment suboptimal. PMID:21272794

  19. Yeast interactions and wine flavour.

    PubMed

    Fleet, Graham H

    2003-09-01

    Wine is the product of complex interactions between fungi, yeasts and bacteria that commence in the vineyard and continue throughout the fermentation process until packaging. Although grape cultivar and cultivation provide the foundations of wine flavour, microorganisms, especially yeasts, impact on the subtlety and individuality of the flavour response. Consequently, it is important to identify and understand the ecological interactions that occur between the different microbial groups, species and strains. These interactions encompass yeast-yeast, yeast-filamentous fungi and yeast-bacteria responses. The surface of healthy grapes has a predominance of Aureobasidium pullulans, Metschnikowia, Hanseniaspora (Kloeckera), Cryptococcus and Rhodotorula species depending on stage of maturity. This microflora moderates the growth of spoilage and mycotoxigenic fungi on grapes, the species and strains of yeasts that contribute to alcoholic fermentation, and the bacteria that contribute to malolactic fermentation. Damaged grapes have increased populations of lactic and acetic acid bacteria that impact on yeasts during alcoholic fermentation. Alcoholic fermentation is characterised by the successional growth of various yeast species and strains, where yeast-yeast interactions determine the ecology. Through yeast-bacterial interactions, this ecology can determine progression of the malolactic fermentation, and potential growth of spoilage bacteria in the final product. The mechanisms by which one species/strain impacts on another in grape-wine ecosystems include: production of lytic enzymes, ethanol, sulphur dioxide and killer toxin/bacteriocin like peptides; nutrient depletion including removal of oxygen, and production of carbon dioxide; and release of cell autolytic components. Cell-cell communication through quorum sensing molecules needs investigation. PMID:12892919

  20. Conservation of yeasts by dehydration

    Microsoft Academic Search

    Martin Beker; Alexander Rapoport

    The presented material concerns the theoretical basis for obtaining high-quality active dry biopreparations. It deals with the present understanding of anabiosis, contains data on yeast resistance against dehydration and the limits for preserving the viability of microorganisms in anabiosis. The process of water transport in yeast biomass during dehydration is discussed.\\u000a The changes and transformations in yeast cells occuring after

  1. Sucrose-Induced Analgesia is related to Sweet Preferences in Children but not Adults

    PubMed Central

    Pepino, M. Yanina; Mennella, Julie A.

    2006-01-01

    The present study tested the hypothesis that the efficacy of sucrose in reducing pain during the Cold Pressor Test (CPT) was related to its hedonic value. To this aim, we determined the most preferred level of sucrose and the analgesic properties of 24% w/v sucrose during the CPT in 242, 5- to 10-year-old children and their mothers. Outcome measures included pain thresholds (the time at which discomfort was first indicated) and pain tolerance (the length of time the hand was kept in the cold water bath). Although children, as a group, preferred significantly higher sucrose concentrations than adults, there were individual differences that allowed us to group them on the basis of those who preferred sucrose concentrations below that used in the CPT (24% w/v) and those who preferred levels ? 24% w/v sucrose. Regardless of such groupings, sucrose was not an effective analgesic in adult women. Unlike adults, the more children liked sucrose, the better its efficacy as an analgesic. That is, children who preferred ?24%w/v sucrose exhibited an increased latency to report pain and tolerated pain for significantly longer periods of time when sucrose was held in their mouths relative to water. This effect was more pronounced among normal weight when compared to overweight/at risk for overweight children. The role that dietary habits and individual differences contribute to the preferences for sweet taste and its physiological consequences in children is an important area for future research. PMID:16298489

  2. 21 CFR 172.896 - Dried yeasts.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 2013-04-01 2013-04-01 false Dried yeasts. 172.896 Section 172.896 Food and Drugs...CONSUMPTION Multipurpose Additives § 172.896 Dried yeasts. Dried yeast (Saccharomyces cerevisiae and Saccharomyces...

  3. 21 CFR 172.896 - Dried yeasts.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 2011-04-01 2011-04-01 false Dried yeasts. 172.896 Section 172.896 Food and Drugs...CONSUMPTION Multipurpose Additives § 172.896 Dried yeasts. Dried yeast (Saccharomyces cerevisiae and Saccharomyces...

  4. 21 CFR 172.896 - Dried yeasts.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 2012-04-01 2012-04-01 false Dried yeasts. 172.896 Section 172.896 Food and Drugs...CONSUMPTION Multipurpose Additives § 172.896 Dried yeasts. Dried yeast (Saccharomyces cerevisiae and Saccharomyces...

  5. 21 CFR 172.896 - Dried yeasts.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 2014-04-01 2014-04-01 false Dried yeasts. 172.896 Section 172.896 Food and Drugs...CONSUMPTION Multipurpose Additives § 172.896 Dried yeasts. Dried yeast (Saccharomyces cerevisiae and Saccharomyces...

  6. 21 CFR 172.896 - Dried yeasts.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...3 2010-04-01 2009-04-01 true Dried yeasts. 172.896 Section 172.896 Food and Drugs...CONSUMPTION Multipurpose Additives § 172.896 Dried yeasts. Dried yeast (Saccharomyces cerevisiae and Saccharomyces...

  7. Alterations of sucrose preference after Roux-en-Y gastric bypass.

    PubMed

    Bueter, M; Miras, A D; Chichger, H; Fenske, W; Ghatei, M A; Bloom, S R; Unwin, R J; Lutz, T A; Spector, A C; le Roux, C W

    2011-10-24

    Roux-en-Y gastric bypass (gastric bypass) patients reportedly have changes in perception and consumption of sweet-tasting foods. This study aimed to further investigate alterations in sweet food intake in rats and sucrose detection in humans after gastric bypass. Wistar rats were randomized to gastric bypass or sham-operations and preference for sucrose (sweet), sodium chloride (salty), citric acid (sour) and quinine hydrochloride (bitter) was assessed with standard two-bottle intake tests (vs. water). Intestinal T1R2 and T1R3 expression and plasma levels of glucagon-like-peptide 1 (GLP-1) and peptide YY (PYY) were measured. Furthermore, obese patients and normal weight controls were tested for sucrose taste detection thresholds pre- and postoperatively. Visual analogue scales measuring hedonic perception were used to determine the sucrose concentration considered by patients and controls as "just about right" pre- and postoperatively. Gastric bypass reduced the sucrose intake relative to water in rats (p<0.001). Preoperative sucrose exposure reduced this effect. Preference or aversion for compounds representative of other taste qualities in naïve rats remained unaffected. Intestinal T1R2 and T1R3 expression was significantly decreased in the alimentary limb while plasma levels of GLP-1 and PYY were elevated after bypass in rats (p=0.01). Bypass patients showed increased taste sensitivity to low sucrose concentrations compared with controls (p<0.05), but both groups considered the same sucrose concentration as "just about right" postoperatively. In conclusion, gastric bypass reduces sucrose intake relative to water in sucrose-naïve rats, but preoperative sucrose experience attenuates this effect. Changes in sucrose taste detection do not predict hedonic taste ratings of sucrose in bypass patients which remain unchanged. Thus, factors other than the unconditional affective value of the taste may also play a role in determining food preferences after gastric bypass. PMID:21827777

  8. Effect of elevated CO[sub 2] and temperature on sucrose phosphate synthase activity and carbohydrate metabolism in rice

    SciTech Connect

    Hussain, M.W.

    1992-01-01

    The kinetics of sucrose phosphate synthase (SPS) activity were studied in leaf extracts of rice (Oryza sativa L. cv. IR-3-). The SPS activity showed hyperbolic and sigmoidal response, respectively, as a function of concentration for its two substrates, UDPG and F6P. The K[sub m] (UDPG) and S[sub 0.5] (F6P) were 2.7 and 2 mM, respectively. The enzyme was activated in an allosteric manner by G6P at low F6P concentrations, while P[sub i] inhibited it. Diel profiles indicated SPS was light activated and the activation was greatest under limiting assay conditions. Leaves were pretreated either with mannose to sequester endogenous P[sub i] or with exogenous P[sub i]. Mannose pretreatment made the enzyme relatively insensitive to p[sub i] inhibition, whereas P[sub i] pretreatment enhanced the inhibitory effect. These data suggest that the rice SPS enzyme exists in two states, a light-active, P[sub i]-insensitive form, and a dark form that is more P[sub i]-sensitive. Based on these kinetic analysis, leaf SPS activity was examined as a function of CO[sub 2]-enrichment and growth temperature for rice plants grown under natural irradiance at 330 and 660 [mu]L CO[sub 2] L[sup [minus]1] and growth temperatures ranging from 25 to 37[degrees]C. CO[sub 2]-enrichment at 28[degrees]C caused a season-long increase (18%) in SPS activity measured under limiting or saturating assay conditions. It is also increased the leaf starch and sucrose content, but lowered the total nitrogen. Sucrose content was higher than starch, suggesting rice is a sucrose and starch storer. In CO[sub 2]-enriched plants, SPS activity increased with growth temperature up to 34[degrees]C, but declined at 38[degrees]C. The increasing temperature caused a significant linear decrease in starch content, whereas sucrose was only slightly decreased, while fructose was increased. The data suggest that up-regulation of SPS activity is an acclimation response of rice to elevated CO[sub 2] and temperature.

  9. Automated motion estimation of root responses to sucrose in two Arabidopsis thaliana genotypes using confocal microscopy.

    PubMed

    Wuyts, Nathalie; Bengough, A Glyn; Roberts, Timothy J; Du, Chengjin; Bransby, M Fraser; McKenna, Stephen J; Valentine, Tracy A

    2011-10-01

    Root growth is a highly dynamic process influenced by genetic background and environment. This paper reports the development of R scripts that enable root growth kinematic analysis that complements a new motion analysis tool: PlantVis. Root growth of Arabidopsis thaliana expressing a plasma membrane targeted GFP (C24 and Columbia 35S:LTI6b-EGFP) was imaged using time-lapse confocal laser scanning microscopy. Displacement of individual pixels in the time-lapse sequences was estimated automatically by PlantVis, producing dense motion vector fields. R scripts were developed to extract kinematic growth parameters and report displacement to ± 0.1 pixel. In contrast to other currently available tools, Plantvis-R delivered root velocity profiles without interpolation or averaging across the root surface and also estimated the uncertainty associated with tracking each pixel. The PlantVis-R analysis tool has a range of potential applications in root physiology and gene expression studies, including linking motion to specific cell boundaries and analysis of curvature. The potential for quantifying genotype × environment interactions was examined by applying PlantVis-R in a kinematic analysis of root growth of C24 and Columbia, under contrasting carbon supply. Large genotype-dependent effects of sucrose were recorded. C24 exhibited negligible differences in elongation zone length and elongation rate but doubled the density of lateral roots in the presence of sucrose. Columbia, in contrast, increased its elongation zone length and doubled its elongation rate and the density of lateral roots. PMID:21630041

  10. Cytosolic cycles regulate the turnover of sucrose in heterotrophic cell-suspension cultures of Chenopodium rubrum L.

    PubMed

    Dancer, J; Hatzfeld, W D; Stitt, M

    1990-09-01

    We have investigated whether sucrose accumulation in heterotrophic cell-suspension cultures of Chenopodium rubrum L. is regulated by a cycle in which sucrose is simultaneously synthesised and degraded. Net sucrose accumulation was measured by monitoring the sucrose content, unidirectional synthesis was monitored by supplying pulses of [(14)C] glucose, and unidirectional degradation was estimated from the difference between unidirectional synthesis and net accumulation. When 50 mM glucose was supplied to carbohydrate-depleted cells there was a rapid net accumulation of sucrose, which stopped after 24 h. The incorporation of (14)C into sucrose was similar to the initial rate of net sucrose accumulation, but rapid (14)C incorporation continued after the cells had stopped accumulating sucrose. A method was developed to rapidly separate sucrose-phosphate synthase (SPS) from uridine-diphosphate-hydrolysing activities which interfered with the assay. The cells contained enough SPS activity to catalyse the observed rate of sucrose synthesis. SPS activity increased in cells which had stopped accumulating sucrose, and the enzyme became less sensitive to inhibition by inorganic phosphate. Sucrose synthase and alkaline invertase activity were four- and twofold higher than SPS activity, and both degradative enzymes increased in cells which had stopped accumulating sucrose. Sucrose synthase is strongly modulated by the concentration of sucrose and by competitive feedback regulation by fructose in these cells. It is concluded that sucrose accumulation ceases in these cells because the rate of degradation of sucrose increases until it matches the rate of synthesis. It is discussed how this cycle is regulated, and how it may interact with the substrate cycle between triose-phosphates and hexose-phosphates (Hatzfeld and Stitt, 1990, Planta 180, 198-204). These cycles allow sucrose turnover to respond in a highly sensitive manner to small changes in the balance between the supply of sucrose and the demand for carbon for respiration and biosynthesis in the cell. PMID:24197100

  11. Sucrose Biotransformation to Fructooligosaccharides by Aspergillus sp. N74 Free Cells

    Microsoft Academic Search

    Oscar Fernando Sánchez; Ana M. Rodriguez; Edelberto Silva; Luis A. Caicedo

    2010-01-01

    Fructooligosaccharide production with the fructosyltransferase from free cells of the native strain Aspergillus sp. N74 at laboratory level was evaluated. The biomass of the native strain Aspergillus sp. N74 was produced in a sucrose fermentation medium and was employed in the enzymatic reaction in solutions of sucrose\\u000a and phosphate buffer, where pH, temperature, and initial sucrose concentration effect were evaluated.

  12. Biological Sensor for Sucrose Availability: Relative Sensitivities of Various Reporter Genes

    Microsoft Academic Search

    WILLIAM G. MILLER; MARIA T. BRANDL; BEATRIZ QUINONES; STEVEN E. LINDOW

    2001-01-01

    A set of three sucrose-regulated transcriptional fusions was constructed. Fusions p61RYTIR, p61RYlac, and p61RYice contain the scrR sucrose repressor gene and the promoterless gfp, lacZ, and inaZ reporter genes, respectively, fused to the scrY promoter from Salmonella enterica serovar Typhimurium. Cells of Erwinia her- bicola containing these fusions are induced only in media amended with sucrose, fructose, or sorbose. While

  13. An assessment of after harvest sucrose losses from sugarcane field to factory

    Microsoft Academic Search

    J. E. Larrahondo; C. O. Briceño; M. Rojas; M. Palma

    2006-01-01

    Sucrose losses between harvesting and milling begin soon after cutting, increasing with the time the cane remains in the field\\u000a or in the mill yards. The deterioration rate depends upon the environmental conditions, the cane variety and the management\\u000a of the harvesting system. In addition, it has been established that leaves and trash also contribute to increase sucrose losses.\\u000a Sucrose

  14. Modeling sucrose hydrolysis in dilute sulfuric acid solutions at pretreatment conditions for lignocellulosic biomass

    Microsoft Academic Search

    Shane Bower; Ranil Wickramasinghe; Nicholas J. Nagle; Daniel J. Schell

    2008-01-01

    Agricultural and herbaceous feedstocks may contain appreciable levels of sucrose. The goal of this study was to evaluate the survivability of sucrose and its hydrolysis products, fructose and glucose, during dilute sulfuric acid processing at conditions typically used to pretreat lignocellulose biomass. Solutions containing 25g\\/l sucrose with 0.1–2.0% (w\\/w) sulfuric acid concentrations were treated at temperatures of 160–200°C for 3–12min.

  15. Interactions of ancymidol with sucrose and ?-naphthaleneacetic acid in promoting asparagus (Asparagus officinalis L.) somatic embryogenesis

    Microsoft Academic Search

    B. Li; D. J. Wolyn

    1997-01-01

    Interactions of varying ancymidol concentrations with those of ?-naphthaleneacetic acid (NAA) or sucrose in embryo induction medium were related to the production and development of asparagus\\u000a (Asparagus officinalis L.) somatic embryos, and to the ability of these embryos to germinate. A significant sucrose×ancymidol interaction was observed\\u000a only for the production of bipolar embryos; 4% sucrose with 0.75 mg l–1 ancymidol

  16. Production of Food Grade Yeasts

    Microsoft Academic Search

    Argyro Bekatorou; Costas Psarianos; Athanasios A. Koutinas

    2006-01-01

    Summary Yeasts have been known to humans for thousands of years as they have been used in traditional fermentation processes like wine, beer and bread making. Today, yeasts are also used as alternative sources of high nutritional value proteins, enzymes and vitamins, and have numerous applications in the health food industry as food additives, conditioners and flavouring agents, for the

  17. Yeast Infections in Immunocompromised Hosts

    Microsoft Academic Search

    Emmanuel Rollides; Thomas J. Walsh

    A number of yeast fungi are pathogenic, but the two genera that contain the most important animal and human pathogens are\\u000a Candida and Cryptococcus. In addition, there are a number of other yeasts that have been, more rarely, implicated in disease.

  18. Yeast interactions and wine flavour

    Microsoft Academic Search

    Graham H. Fleet

    2003-01-01

    Wine is the product of complex interactions between fungi, yeasts and bacteria that commence in the vineyard and continue throughout the fermentation process until packaging. Although grape cultivar and cultivation provide the foundations of wine flavour, microorganisms, especially yeasts, impact on the subtlety and individuality of the flavour response. Consequently, it is important to identify and understand the ecological interactions

  19. Preservation of manipulated yeast diet

    Microsoft Academic Search

    Joong Kyun Kim; Hae-Yoon Chung

    2002-01-01

    Manipulated yeast diet can be usedfor seed production of aquacultural organisms.Various methods for preserving the yeast dietduring the periods of circulation in marketwere tested, and the preservation of the yeastdiet by freeze-drying was the best. With thispreservation method, the manipulated yeastswere maintained fairly well (up to 71%) whenstored for three weeks under refrigeratedcondition (4 °C), while more than 80% ofthe

  20. Ultrasonic velocity assay of extracellular invertase in living yeasts.

    PubMed

    Resa, Pablo; Elvira, Luis; Sierra, Carlos; Espinosa, Francisco Montero de

    2009-01-01

    The use of a low-intensity ultrasonic technique (noninvasive, nondestructive, on-line, and able to assess opaque samples) to monitor the kinetics of invertase hydrolysis is presented. Adiabatic compressibility has been shown to be sensitive to sugar species: ultrasonic velocity increasing as saccharose is transformed into glucose and fructose. The influence of initial sucrose mass concentration (2-60%), temperature (25-55 degrees C), pH (3.5-6.5), and number of microorganisms (10(5)-10(9) yeasts/ml) on the reaction rate, catalyzed by the extracellular invertases of intact Saccharomyces cerevisiae cells, has been measured. The results were proven to be in strict agreement with the optimal kinetic parameters of the enzyme. Ultrasonic velocity variations are explained in terms of changes of the solute concentrations in the mixture water-saccharose-glucose/fructose and calculated from the velocity of ultrasound in the corresponding pure sugar solutions. A linear relationship between the initial rate of ultrasonic velocity and the number of yeasts (enzymes) is pointed out. PMID:18835377

  1. Mechanistic investigation of domain specific unfolding of human serum albumin and the effect of sucrose

    PubMed Central

    Yadav, Rajeev; Sen, Pratik

    2013-01-01

    This study is devoted to understand the unfolding mechanism of a multidomain protein, human serum albumin (HSA), in absence and presence of the sucrose by steady-state and time-resolved fluorescence spectroscopy with domain specific marker molecules and is further being substantiated by molecular dynamics (MD) simulation. In water, the domain III of HSA found to unfold first followed by domains I and II as the concentration of GnHCl is increased in the medium. The sequential unfolding behavior of different domains of HSA remains same in presence of sucrose; however, a higher GnHCl concentration is required for unfolding, suggesting stabilizing effect of sucrose on HSA. Domain I is found to be most stabilized by sucrose. The stabilization of domain II is somewhat similar to domain I, but the effect of sucrose on domain III is found to be very small. MD simulation also predicted a similar behavior of sucrose on HSA. The stabilizing effect of sucrose is explained in terms of the entrapment of water molecules in between HSA surface and sucrose layer as well as direct interaction between HSA and sucrose. PMID:24038622

  2. Combined compared to dissociated oral and intestinal sucrose stimuli induce different brain hedonic processes.

    PubMed

    Clouard, Caroline; Meunier-Salaün, Marie-Christine; Meurice, Paul; Malbert, Charles-Henri; Val-Laillet, David

    2014-01-01

    The characterization of brain networks contributing to the processing of oral and/or intestinal sugar signals in a relevant animal model might help to understand the neural mechanisms related to the control of food intake in humans and suggest potential causes for impaired eating behaviors. This study aimed at comparing the brain responses triggered by oral and/or intestinal sucrose sensing in pigs. Seven animals underwent brain single photon emission computed tomography ((99m)Tc-HMPAO) further to oral stimulation with neutral or sucrose artificial saliva paired with saline or sucrose infusion in the duodenum, the proximal part of the intestine. Oral and/or duodenal sucrose sensing induced differential cerebral blood flow changes in brain regions known to be involved in memory, reward processes and hedonic (i.e., pleasure) evaluation of sensory stimuli, including the dorsal striatum, prefrontal cortex, cingulate cortex, insular cortex, hippocampus, and parahippocampal cortex. Sucrose duodenal infusion only and combined sucrose stimulation induced similar activity patterns in the putamen, ventral anterior cingulate cortex and hippocampus. Some brain deactivations in the prefrontal and insular cortices were only detected in the presence of oral sucrose stimulation. Finally, activation of the right insular cortex was only induced by combined oral and duodenal sucrose stimulation, while specific activity patterns were detected in the hippocampus and parahippocampal cortex with oral sucrose dissociated from caloric load. This study sheds new light on the brain hedonic responses to sugar and has potential implications to unravel the neuropsychological mechanisms underlying food pleasure and motivation. PMID:25147536

  3. Water Restriction and Fluid Temperature Alter Preference for Water and Sucrose Solutions

    PubMed Central

    Bales, Michelle B.; Breza, Joseph M.; Houpt, Thomas A.; Smith, James C.; Contreras, Robert J.

    2012-01-01

    The role of diet temperature in ingestive behavior is poorly understood. We examined the importance of stimulus temperature and water-restriction state on the preference for and intake of water and sucrose. Using custom-designed equipment that allows us to monitor and maintain solution temperatures during testing (±0.1 °C), we conducted a series of 2-bottle preference tests (10 °C water vs. sucrose 10–40 °C) and brief access tests (10–40 °C water and sucrose). Water-restricted rats preferred cold water over any sucrose concentration (0.0–1.0 M) if the sucrose was 30 or 40 °C, whereas the same rats preferred sucrose at all concentrations and temperatures when unrestricted suggesting that the water-restriction state interacts with temperature preference. In a series of brief-access tests using a Davis Rig (MS-180), rats reduced licking to cold sucrose compared with 20 °C sucrose, suggesting that unlike water, cold temperature reduced the palatability of sucrose. PMID:22109629

  4. Combined compared to dissociated oral and intestinal sucrose stimuli induce different brain hedonic processes

    PubMed Central

    Clouard, Caroline; Meunier-Salaün, Marie-Christine; Meurice, Paul; Malbert, Charles-Henri; Val-Laillet, David

    2014-01-01

    The characterization of brain networks contributing to the processing of oral and/or intestinal sugar signals in a relevant animal model might help to understand the neural mechanisms related to the control of food intake in humans and suggest potential causes for impaired eating behaviors. This study aimed at comparing the brain responses triggered by oral and/or intestinal sucrose sensing in pigs. Seven animals underwent brain single photon emission computed tomography (99mTc-HMPAO) further to oral stimulation with neutral or sucrose artificial saliva paired with saline or sucrose infusion in the duodenum, the proximal part of the intestine. Oral and/or duodenal sucrose sensing induced differential cerebral blood flow changes in brain regions known to be involved in memory, reward processes and hedonic (i.e., pleasure) evaluation of sensory stimuli, including the dorsal striatum, prefrontal cortex, cingulate cortex, insular cortex, hippocampus, and parahippocampal cortex. Sucrose duodenal infusion only and combined sucrose stimulation induced similar activity patterns in the putamen, ventral anterior cingulate cortex and hippocampus. Some brain deactivations in the prefrontal and insular cortices were only detected in the presence of oral sucrose stimulation. Finally, activation of the right insular cortex was only induced by combined oral and duodenal sucrose stimulation, while specific activity patterns were detected in the hippocampus and parahippocampal cortex with oral sucrose dissociated from caloric load. This study sheds new light on the brain hedonic responses to sugar and has potential implications to unravel the neuropsychological mechanisms underlying food pleasure and motivation. PMID:25147536

  5. ATP-induced sucrose efflux from red-beet tonoplast vesicles.

    PubMed

    Echeverría, E; Gonzalez, P C

    2000-06-01

    Sucrose efflux from the vacuole of mobilizing red-beet (Beta vulgaris L.) hypocotyl cells was investigated using purified tonoplast vesicles. Tonoplast vesicle purity was assured by the immunoreactivity to antibodies raised against the vacuolar ATPase and by the strong inhibition exhibited by the H+-ATPase to bafilomycin-A and NO3-. Inhibition of the H+-ATPase by vanadate and azide was negligible. Sucrose was loaded into tonoplast vesicles by using the pH-jump method of energization. Addition of ATP to sucrose-loaded vesicles in the presence of bafilomycin-A resulted in efflux of a significant amount of sucrose. During ATP-induced sucrose efflux, bafilomycin-insensitive ATPase activity increased significantly with no increase in H+-translocating activity. The additional bafilomycin-A insensitive ATPase activity observed in sucrose-loaded vesicles was completely inhibited by vanadate as was the efflux of sucrose. Similar to vanadate, thapsigargin was also inhibitory to sucrose efflux and to the bafilomycin-A insensitive ATPase activity. The data indicate that vacuolar sucrose can be actively mobilized by a specific ATP-dependent efflux mechanism. PMID:10923706

  6. Effect of low temperature stress on the expression of sucrose synthetase in spring and winter wheat plants. Development of a monoclonal antibody against wheat germ sucrose synthetase.

    PubMed

    Newsted, W J; Chibbar, R N; Georges, F

    1991-01-01

    A monoclonal antibody against wheat germ sucrose synthetase is developed and characterized. Its use in studying the effect of cold acclimation on the expression of sucrose synthetase in winter and spring wheat plants is described. The antibody shows cross-reactivity with sucrose synthetase from maize and pea plants, as well as carrot cells. A gradual accumulation of the enzyme as a function of time spent at 2 degrees C is observed in both wheat varieties. In contrast, an initial sharp rise in the mRNA level is observed, which agrees with the previously reported response of maize plants subjected to anaerobic stress. PMID:1828354

  7. Agriculturally important yeasts: Biological control of field and postharvest diseases using yeast antagonists, and yeasts as pathogens of plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two important agricultural aspects of yeasts, control of plant diseases through application of yeasts as the control agent, and yeasts that are plant pathogens are reviewed. Yeasts as biocontrol organisms are presented first, followed by a discussion of some of the more common plant pathogenic yeas...

  8. Minimal nutritional requirements for immobilized yeast.

    PubMed

    Chen, C; Dale, M C; Okos, M R

    1990-12-01

    The effect of reduced nutritional levels (particularly nitrogen source) for immobilized K. fragilis type yeast were studied using a trickle flow, "differential" plug flow type reactor with cells immobilized by adsorption onto an absorbant packing matrix. Minimizing nutrient levels in a feed stream to an immobilized cell reactor (ICR) might have the benefits of reducing cell growth and clogging problems in the ICR, reducing feed preparation costs, as well as reducing effluent disposal costs. In this study step changes in test feed medium nutrient compositions were introduced to the ICR, followed by a return to a basal medium. Gas evolution rates were monitored and logged on a continuous basis, and effluent cell density was used as an indicator of cell growth rate of the immobilized cell mass. Startup of the reactor using a YEP medium showed a rapid buildup of cells in the reactor during the initial 110 h operation. The population density then stabilized at 1.6 x 10(11) cells/g sponge. A defined medium containing a complex mix of essential nutrients with an inorganic nitrogen source (ammonium sulfate) was able to maintain 90% of the productivity in the ICR as compared to the YEP medium, but proved unable to promote growth of the immobilized cell mass during startup. Experiments on reduced ammonium sulfate in the defined medium, and reduced yeast extract and peptone in YEP medium indicated that stable productivity could be maintained for extended periods (80 h) in the complete absence of any nutrients besides a few salts (potassium phosphate and magnesium sulfate). It was found that productivity rates dropped by 35-65% from maximal values as nitrogenous nutrients were eliminated from the test mediums, while growth rates (as determined by shed cell density from the reactor) dropped by 75-95%. Thus, nutritional deficiencies largely decoupled growth and productivity of the immobilized yeast which suggests productivity is both growth- and non-growth-associated for the immobilized cells. A yeast extract concentration of 0.375 g/L with or without 1 g/L ammonium sulfate was determined to be the minimum level which gave a sustained increase in productivity rates as compared to the nutritionally deficient salt medium. This represents a 94% reduction in complex nitrogenous nutrient levels compared to standard YEP batch medium (3 g/L YE and 3.5 g/L peptone). PMID:18595037

  9. Efficient Procedure for Extracting Tylenchulus semipenetrans from Citrus Roots

    PubMed Central

    Greco, N.; D'Addabbo, T.

    1990-01-01

    Investigations were undertaken to determine the suitability of sucrose and magnesium sulphate solutions and a silica colloidal suspension with centrifugation for extracting Tylenchulus semipenetrans from citrus roots. The efficiency of incubation, sodium hypochlorite, centrifugation, and maceration methods was also compared. Numbers of females recovered by centrifugation with colloidal silica were greater than those from sucrose or magnesium sulphate. Incubation, sodium hypochlorite, and centrifugation methods were satisfactory for extracting eggs, second-stage juveniles, and males, whereas the maceration-sieving method was less efficient. Combining the sodium hypochlorite method with a 15-second maceration followed by centrifugation in colloidal silica reduced the recovery of T. semipenetrans females from citrus roots. PMID:19287763

  10. Sugarcane molasses and yeast powder used in the Fructooligosaccharides production by Aspergillus japonicus-FCL 119T and Aspergillus niger ATCC 20611.

    PubMed

    Dorta, Claudia; Cruz, Rubens; de Oliva-Neto, Pedro; Moura, Danilo José Camargo

    2006-12-01

    Different concentrations of sucrose (3-25% w/v) and peptone (2-5% w/v) were studied in the formulation of media during the cultivation of Aspergillus japonicus-FCL 119T and Aspergillus niger ATCC 20611. Moreover, cane molasses (3.5-17.5% w/v total sugar) and yeast powder (1.5-5% w/v) were used as alternative nutrients for both strains' cultivation. These media were formulated for analysis of cellular growth, beta-Fructosyltransferase and Fructooligosaccharides (FOS) production. Transfructosylating activity (U ( t )) and FOS production were analyzed by HPLC. The highest enzyme production by both the strains was 3% (w/v) sucrose and 3% (w/v) peptone, or 3.5% (w/v) total sugars present in cane molasses and 1.5% (w/v) yeast powder. Cane molasses and yeast powder were as good as sucrose and peptone in the enzyme and FOS (around 60% w/w) production by studied strains. PMID:16835781

  11. Sucrose induces expression of the sorbitol-6-phosphate dehydrogenase gene in source leaves of loquat.

    PubMed

    Suzuki, Yasuo; Dandekar, Abhaya M

    2014-03-01

    Rosaceae fruit trees use sorbitol and sucrose as translocating sugars and the sorbitol-to-sucrose ratio in source leaves determines apple fruit quality. Here, we investigate the effects of sugars on the expression of genes encoding key photosynthetic enzymes, including sorbitol-6-phosphate dehydrogenase (S6PDH, EC 1.1.1.200), sucrose phosphate synthase (SPS, EC 2.4.1.14), and ADP-glucose pyrophosphorylase (ADPGPPase, EC 2.7.7.27) to understand the sugar-signaling mechanism in Rosaceae fruit trees. Mature leaf-petiole cuttings of loquat (Eriobotrya japonica Lindl. cv. Mogi) were supplied with a water, sorbitol or sucrose solution for 2?days at 20°C. The relative levels of the transcripts were analyzed by real-time polymerase chain reaction (PCR). S6PDH transcription was decreased by sorbitol but drastically increased by sucrose. SPS and ADPGPPase large subunit transcription were decreased by sucrose and sorbitol. The simultaneous application of sorbitol and sucrose revealed that S6PDH transcription increased in a dose-dependent manner with sucrose. These results show that both sorbitol and sucrose work as signaling molecules in source organs of Rosaceae fruit trees. These trees have mechanisms to positively keep sorbitol as the dominant translocating sugar, suggesting that sorbitol plays an important role in their survival strategy. Effects of various sugars on S6PDH expression were investigated. Palatinose, a sucrose analog, increased S6PDH transcription much more drastically than sucrose. Mannose and 3-O-methylglucose, glucose analogs, also increased S6PDH transcription; however, glucose did not. Models of sugar signaling in source organs of Rosaceae fruit trees are discussed. PMID:24102486

  12. Vacuoles of Candida yeast as a specialized niche for Helicobacter pylori.

    PubMed

    Siavoshi, Farideh; Saniee, Parastoo

    2014-05-14

    Helicobacter pylori (H. pylori) are resistant to hostile gastric environments and antibiotic therapy, reflecting the possibility that they are protected by an ecological niche, such as inside the vacuoles of human epithelial and immune cells. Candida yeast may also provide such an alternative niche, as fluorescently labeled H. pylori were observed as fast-moving and viable bacterium-like bodies inside the vacuoles of gastric, oral, vaginal and foodborne Candida yeasts. In addition, H. pylori-specific genes and proteins were detected in samples extracted from these yeasts. The H. pylori present within these yeasts produce peroxiredoxin and thiol peroxidase, providing the ability to detoxify oxygen metabolites formed in immune cells. Furthermore, these bacteria produce urease and VacA, two virulence determinants of H. pylori that influence phago-lysosome fusion and bacterial survival in macrophages. Microscopic observations of H. pylori cells in new generations of yeasts along with amplification of H. pylori-specific genes from consecutive generations indicate that new yeasts can inherit the intracellular H. pylori as part of their vacuolar content. Accordingly, it is proposed that yeast vacuoles serve as a sophisticated niche that protects H. pylori against the environmental stresses and provides essential nutrients, including ergosterol, for its growth and multiplication. This intracellular establishment inside the yeast vacuole likely occurred long ago, leading to the adaptation of H. pylori to persist in phagocytic cells. The presence of these bacteria within yeasts, including foodborne yeasts, along with the vertical transmission of yeasts from mother to neonate, provide explanations for the persistence and propagation of H. pylori in the human population. This Topic Highlight reviews and discusses recent evidence regarding the evolutionary adaptation of H. pylori to thrive in host cell vacuoles. PMID:24833856

  13. Yeasts: From genetics to biotechnology

    SciTech Connect

    Russo, S.; Poli, G. [Univ. of Milan (Italy); Siman-Tov, R.B. [Univ. of Jerusalem, Rehovot (Israel)

    1995-12-31

    Yeasts have been known and used in food and alcoholic fermentations ever since the Neolithic Age. In more recent times, on the basis of their peculiar features and history, yeasts have become very important experimental models in both microbiological and genetic research, as well as the main characters in many fermentative production processes. In the last 40 years, advances in molecular biology and genetic engineering have made possible not only the genetic selection of organisms, but also the genetic modification of some of them, especially the simplest of them, such as bacteria and yeasts. These discoveries have led to the availability of new yeast strains fit to fulfill requests of industrial production and fermentation. Moreover, genetically modified and transformed yeasts have been constructed that are able to produce large amounts of biologically active proteins and enzymes. Thus, recombinant yeasts make it easier to produce drugs, biologically active products, diagnostics, and vaccines, by inexpensive and relatively simple techniques. Yeasts are going to become more and more important in the {open_quotes}biotechnological revolution{close_quotes} by virtue of both their features and their very long and safe use in human nutrition and industry. 175 refs., 4 figs., 6 tabs.

  14. Efficient microwave assisted synthesis of novel 1,2,3-triazole-sucrose derivatives by cycloaddition reaction of sucrose azides and terminal alkynes.

    PubMed

    Potewar, Taterao M; Petrova, Krasimira T; Barros, M Teresa

    2013-09-20

    Novel 1-(1',2,3,3',4,4',6-hepta-O-acetyl-6'-deoxy-sucros-6'-yl)-4-substituted-1,2,3-triazoles were synthesized by microwave assisted copper catalyzed 1,3-dipolar cycloaddition of sucrose derived azides with terminal alkynes in excellent yields and in short reaction times. The compound 1',2,3,3',4,4',6-hepta-O-acetyl-6'-azido-6'-deoxy-sucrose was regioselectively synthesized from sucrose by improved procedure and used for the cycloadditions. By combining carbohydrate and 1,2,3-triazole structural motifs, a library of 1,2,3-triazole-sucrose conjugates have been obtained. PMID:23872329

  15. Yeast Breads: Made at Home. 

    E-print Network

    Cox, Maeona; Harris, Jimmie Nell; Reasonover, Frances; Mason, Lousie

    1957-01-01

    tablespoons sugar ll/z teaspoons salt cup shortening 1/4 CUP lukewarm water 2 packages yeast or 2 yeast cakes 39'4 CUPS flour Apple Coffee Cake. Scald milk and stir in sugar, salt and shorten~r , Cool to lukewarm. Sprinkle or crumble yeast tnto nit1.... Honey twist. Streusel coffee cake. Butterscotch pecan rolls. STREUSEL COFFEE CAKE 2 tablespoons butter or margarine 2 tablespoons sugar cup flour CUP fine bread crumbs 1/2 teaspoon cinnamon Cream fat and sugar. Add flour, bread crumbs...

  16. Effect of Sucrose Concentration on Sucrose-Dependent Adhesion and Glucosyltransferase Expression of S. mutans in Children with Severe Early-Childhood Caries (S-ECC)

    PubMed Central

    Zhao, Wei; Li, Wenqing; Lin, Jiacheng; Chen, Zhuoyu; Yu, Dongsheng

    2014-01-01

    Sucrose, extracellular polysaccharide, and glucosyltransferases (GTFs) are key factors in sucrose-dependent adhesion and play important roles in the process of severe early-childhood caries (S-ECC). However, whether sucrose concentration regulates gtf expression, extracellular polysaccharide synthesis, and sucrose-dependent adhesion is related to the different genotypes of S. mutans isolated from ECC in children and still needs to be investigated. In this study, 52 strains of S. mutans were isolated from children with S-ECC and caries-free (CF) children. Water-insoluble glucan (WIG) synthesis was detected by the anthrone method, adhesion capacity by the turbidimetric method, and expression of gtf by RT-PCR in an in vitro model containing 1%–20% sucrose. The genotypes of S. mutans were analyzed by AP-PCR. The results showed that WIG synthesis, adhesion capacity, and gtf expression increased significantly when the sucrose concentration was from 1% to 10%. WIG synthesis and gtfB as well as gtfC expression of the 1% and 5% groups were significantly lower than those of the 10% and 20% groups (p < 0.05). There were no significant differences between the 10% and 20% groups. The fingerprints of S. mutans detected from individuals in the S-ECC group exhibited a significant difference in diversity compared with those from CF individuals (p < 0.05). Further, the expression of gtfB and gtfC in the S-ECC group was significantly different among the 1- to 5-genotype groups (p < 0.05). It can be concluded that sucrose-dependent adhesion might be related to the diversity of genotypes of S. mutans, and the 10% sucrose level can be seen as a “turning point” and essential factor for the prevention of S-ECC. PMID:25207825

  17. Transgenic cotton over-producing spinach sucrose phosphate synthase showed enhanced leaf sucrose synthesis and improved fiber quality under controlled environmental conditions

    Microsoft Academic Search

    Candace H. Haigler; Bir Singh; Deshui Zhang; Sangjoon Hwang; Chunfa Wu; Wendy X. Cai; Mohamed Hozain; Wonhee Kang; Brett Kiedaisch; Richard E. Strauss; Eric F. Hequet; Bobby G. Wyatt; Gay M. Jividen; A. Scott Holaday

    2007-01-01

    Prior data indicated that enhanced availability of sucrose, a major product of photosynthesis in source leaves and the carbon\\u000a source for secondary wall cellulose synthesis in fiber sinks, might improve fiber quality under abiotic stress conditions.\\u000a To test this hypothesis, a family of transgenic cotton plants (Gossypium\\u000a hirsutum cv. Coker 312 elite) was produced that over-expressed spinach sucrose-phosphate synthase (SPS)

  18. Cloning, Developmental, and Tissue-Specific Expression of Sucrose:Sucrose 1-Fructosyl Transferase from Taraxacum officinale. Fructan Localization in Roots1

    Microsoft Academic Search

    Wim Van den Ende; An Michiels; Dominik Van Wonterghem; Rudy Vergauwen; AndreVan Laere

    Sucrose:sucrose 1-fructosyl transferase (1-SST) is the key enzyme initiating fructan synthesis in Asteraceae. Using reverse transcriptase-PCR, we isolated the cDNA for 1-SST from Taraxacum officinale. The cDNA-derived amino acid sequence showed very high homology to other Asteracean 1-SSTs (Cichorium intybus 86%, Cynara scolymus 82%, Helianthus tuberosus 80%), but homology to 1-SST from Allium cepa (46%) and Aspergillus foetidus (18%) was

  19. Polyglutamine misfolding in yeast

    PubMed Central

    2011-01-01

    Protein misfolding is associated with many human diseases, including neurodegenerative diseases, such as Alzheimer disease, Parkinson disease and Huntington disease. Protein misfolding often results in the formation of intracellular or extracellular inclusions or aggregates. Even though deciphering the role of these aggregates has been the object of intense research activity, their role in protein misfolding diseases is unclear. Here, I discuss the implications of studies on polyglutamine aggregation and toxicity in yeast and other model organisms. These studies provide an excellent experimental and conceptual paradigm that contributes to understanding the differences between toxic and protective trajectories of protein misfolding. Future studies like the ones discussed here have the potential to transform basic concepts of protein misfolding in human diseases and may thus help to identify new therapeutic strategies for their treatment. PMID:22052348

  20. Shallow-burial dolomite cement: a major component of many ancient sucrosic dolomites

    Microsoft Academic Search

    Philip W. Choquette; Eric E. Hiatt

    2008-01-01

    Dolomite cement is a significant and widespread component of Phanerozoic sucrosic dolomites. Cements in dolomites that were never deeply buried are limpid, have planar faces (non-saddle forms), often distinct zonation in cathodoluminescence and form syntaxial overgrowths on crystals facing pores. Five samples of sucrosic dolomites, interpreted as having had mostly lime- mudstone or wackestone precursors in four carbonate aquifers, provide

  1. X-ray fluorescence and multivariate analysis for sucrose quantification in sugarcane

    NASA Astrophysics Data System (ADS)

    Melquiades, Fábio L.; Bortoleto, Gisele G.; Neme, Fernanda F.; Ton, Ariel; Bueno, Maria I. M. S.

    2013-05-01

    Currently the methods used for determining the sucrose content in sugarcane are made in the clarified juice. In this study portable energy dispersive X-ray fluorescence (EDXRF) together with chemometric tools was used to quantify sucrose through the stem, lief and juice. The best results were obtained for the stem, with means relative deviation of around 6%.

  2. Changes in Juice Quality and Sugarcane Yield with Recurrent Selection for Sucrose

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugarcane (Saccharum spp. hybrids) breeding programs in Louisiana have made improving sucrose content a top priority. The cultivars with the highest sucrose content are crossed, and a new generation of cultivars is selected from the progeny. This study was designed to test the hypothesis that six c...

  3. MITOCHONDRIAL LOCALIZATION AND A PUTATIVE SIGNALING FUNCTION OF SUCROSE SYNTHASE IN MAIZE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In many organisms, an increasing number of proteins seem to play two or more unrelated roles. Here, we report that maize sucrose synthase (SUS) is distributed in organelles and may have additional roles besides sucrose catabolism. Bioinformatics analysis predicts that among the three maize SUS isofo...

  4. Effects of sucrose on photosynthesis and phosphoenolpyruvate carboxylase activity of in vitro cultured strawberry plantlets

    Microsoft Academic Search

    Chafik Hdider; Yves Desjardins

    1994-01-01

    Photosynthesis and phosphoenolpyruvate carboxylase activity were investigated in 5, 10 and 28 day-old micropropagated strawberry plantlets (Fragaria x ananassa Duch. cv Kent) rooted in vitro with different levels of sucrose (0, 1, 3 and 5%) on cellulose plugs (Sorbarods). The photosynthetic capability was influenced by the level of sucrose in the culture medium with the largest rates of photosynthesis corresponding

  5. Sucrose regulation of ADP-glucose pyrophosphorylase subunit genes transcript levels in leaves and fruits

    NASA Technical Reports Server (NTRS)

    Li, Xiangyang; Xing, Jinpeng; Gianfagna, Thomas J.; Janes, Harry W.

    2002-01-01

    ADP-glucose pyrophosphorylase (AGPase, EC2.7.7.27) is a key regulatory enzyme in starch biosynthesis. The enzyme is a heterotetramer with two S and two B subunits. In tomato, there are three multiple forms of the S subunit gene. Agp S1, S2 and B are highly expressed in fruit from 10 to 25 days after anthesis. Agp S3 is only weakly expressed in fruit. Sucrose significantly elevates expression of Agp S1, S2 and B in both leaves and fruits. Agp S1 exhibits the highest degree of regulation by sucrose. In fact, sucrose may be required for Agp S1 expression. For excised leaves incubated in water, no transcripts for Agp S1 could be detected in the absence of sucrose, whereas it took up to 16 h in water before transcripts were no longer detectable for Agp S2 and B. Neither Agp S3 nor the tubulin gene is affected by sucrose, demonstrating that this response is specifically regulated by a carbohydrate metabolic signal, and is not due to a general increase in metabolism caused by sucrose treatment. Truncated versions of the promoter for Agp S1 indicate that a specific region 1.3-3.0 kb upstream from the transcription site is responsible for sucrose sensitivity. This region of the S1 promoter contains several cis-acting elements present in the promoters of other genes that are also regulated by sucrose. c2002 Elsevier Science Ireland Ltd. All rights reserved.

  6. Functional characterization of the sucrose isomerase responsible for trehalulose production in plant-associated Pectobacterium species.

    PubMed

    Nam, Cheon-Hyeon; Seo, Dong-Ho; Jung, Jong-Hyun; Koh, Young-Jin; Jung, Jae-Sung; Heu, Sunggi; Oh, Chang-Sik; Park, Cheon-Seok

    2014-02-01

    Fifty-three plant-associated microorganisms were investigated for their ability to convert sucrose to its isomers. These microorganisms included one Dickeya zeae isolate and 7 Enterobacter, 3 Pantoea, and 43 Pectobacterium species. Eleven out of the 53 strains (21%) showed the ability to transform sucrose to isomaltulose and trehalulose. Among those, Pectobacterium carotovorum KKH 3-1 showed the highest bioconversion yield (97.4%) from sucrose to its isomers. In this strain, the addition of up to 14% sucrose in the medium enhanced sucrose isomerase (SIase) production. The SIase activity at 14% sucrose (47.6 U/mg dcw) was about 3.6-fold higher than that of the negative control (13.3 U/mg dcw at 0% sucrose). The gene encoding SIase, which is comprised a 1776 bp open reading frame (ORF) encoding 591 amino acids, was cloned from P. carotovorum KKH 3-1 and expressed in Escherichia coli. The recombinant SIase (PCSI) was shown to have optimum activity at pH 6.0 and 40 °C. The reaction temperature significantly affected the ratio of sucrose isomers produced by PCSI. The amount of trehalulose increased from 47.5% to 79.1% as temperature was lowered from 50 °C to 30 °C, implying that SIase activity can be controlled by reaction temperature. PMID:24411451

  7. Diminished Reactivity of Postmature Human Infants to Sucrose Compared with Term Infants.

    ERIC Educational Resources Information Center

    Smith, Barbara A.; And Others

    1992-01-01

    This study of healthy 39-week-old infants, so-called term infants, and chronically stressed 42-week-old infants, so-called postmature infants, showed that sucrose was extremely effective in calming term infants but less effective in calming postmature infants. Results supported the hypothesis that sucrose engages an opioid system in infants. (BG)

  8. Transesterification of Sucrose in Organic Medium: Study of Acyl Group Migrations

    Microsoft Academic Search

    Valérie Molinier; Krzysztof Wisniewski; Alain Bouchu; Juliette Fitremann; Yves Queneau

    2003-01-01

    The tendency of the acyl groups located on the glucose part of sucrose fatty acid esters to undergo intramolecular migrations in organic medium and the regioselectivity of some transesterifications of sucrose were investigated by HPLC, in situ NMR spectroscopy and preparative methods. Extensive acylation on secondary positions of the glucose moiety followed by migrations is general for base catalysed transesterification.

  9. Determination of structural requirements and probable regulatory effectors for membrane association of maize sucrose synthase 1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sucrose synthase (SUS) cleaves sucrose to form UDP-glucose and fructose, and exists in soluble (s-SUS) and membrane-associated (m-SUS) forms, with the latter proposed to channel UDP-glucose to the cellulose synthase complex on the plasma membrane of plant cells during synthesis of cellulose. However...

  10. Poly(sucrose) micro particles preparation and their use as biomaterials.

    PubMed

    Sahiner, Nurettin; Sagbas, Selin; Turk, Mustafa

    2014-05-01

    Crosslinked p(sucrose) micro particles were synthesized for the first time from sucrose in water-in-oil microemulsion. Using divinyl sulfone (DVS) as crosslinker via reverse micelles of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) p(sucrose) micro particles formed in a single step with very high yield (>90%). The particles have wide size distributions, and negative zeta potential, -27.30 mV, and can be made magnetic field responsive. P(sucrose) particles were shown to be degradable at pHs of 2.5 and 11. Dopamine and gallic acid were used as model drugs for absorption/release studies from p(sucrose) particles. Interestingly, it was shown that p(sucrose) microparticles can be a nutrient for Escherichia coli, and maybe used as a growth medium for other cells, bacteria and organisms. Additionally, the cytotoxic effect of p(sucrose) particles were determined as 26 and 32.5% dead cells against MDA MB-231 cancerous cells and L929 fibroblast cells at 100 ug/ml concentration, respectively. P(sucrose) particles can be safely used for in vivo applications. PMID:24583047

  11. Determination of physiological age of potato tubers with using sucrose, citric and malic acid as indicators

    Microsoft Academic Search

    W. Reust; J. Aerny

    1985-01-01

    The use of endogenous compounds as indicators of physiological age was studied in seed tubers of cv. Bintje produced at two locations. Dormancy and the incubation period of seed tubers were measured and sucrose, citric and malic acid analysed. Sucrose content in tubers was lowest at the beginning of sprouting, 0.1 to 0.2% of fresh weight (FW), and increased with

  12. NMR, Molecular Modeling, and Crystallographic Studies of Lentil Lectin-Sucrose Interaction*

    E-print Network

    Hamelryck, Thomas

    NMR, Molecular Modeling, and Crystallographic Studies of Lentil Lectin-Sucrose Interaction- ing site of lentil lectin have been characterized through elucidation of a crystalline complex at 1, and molecular modeling. In the crys- tal, the lentil lectin dimer binds one sucrose molecule per monomer

  13. Pursuing the Pavlovian Contributions to Induction in Rats Responding for 1% Sucrose Reinforcement

    ERIC Educational Resources Information Center

    Weatherly, Jeffrey N.; Huls, Amber; Kulland, Ashley

    2007-01-01

    The present study investigated whether Pavlovian conditioning contributes, in the form of the response operandum serving as a conditioned stimulus, to the increase in the rate of response for 1% liquid-sucrose reinforcement when food-pellet reinforcement is upcoming. Rats were exposed to conditions in which sign tracking for 1% sucrose was…

  14. Randomised trial of analgesic effects of sucrose, glucose, and pacifiers in term neonates

    PubMed Central

    Carbajal, R; Chauvet, X; Couderc, S; Olivier-Martin, M

    1999-01-01

    Objectives To assess and compare the analgesic effects of orally administered glucose and sucrose and pacifiers. To determine the synergistic analgesic effect of sucrose and pacifiers. Design Randomised prospective study with validated behavioural acute pain rating scale. Setting Maternity ward. Participants 150 term newborns undergoing venepuncture randomly assigned to one of six treatment groups: no treatment; placebo (2 ml sterile water); 2 ml 30% glucose; 2 ml 30% sucrose; a pacifier; and 2 ml 30% sucrose followed by a pacifier. Results Median (interquartile) pain scores during venepuncture were 7 (5-10) for no treatment; 7 (6-10) for placebo (sterile water); 5 (3-7) for 30% glucose; 5 (2-8) for 30% sucrose; 2 (1-4) for pacifier; and 1 (1-2) for 30% sucrose plus pacifier. Mann-Whitney U test P values for comparisons of 30% glucose, 30% sucrose, pacifier, and 30% sucrose plus pacifier versus placebo (sterile water) were 0.005, 0.01, <0.0001, and <0.0001, respectively. Differences between group median pain scores for these comparisons were 2 (95% confidence interval 1 to 4), 2 (0 to 4), 5 (4 to 7), and 6 (5 to 8), respectively. P values for comparisons of 30% glucose, 30% sucrose, and 30% sucrose plus pacifier versus pacifier were 0.0001, 0.001, and 0.06, respectively. Differences between group medians for these comparisons were 3 (2 to 5), 3 (1 to 5), and 1 (0 to 2), respectively. Conclusion The analgesic effects of concentrated sucrose and glucose and pacifiers are clinically apparent in newborns, pacifiers being more effective than sweet solutions. The association of sucrose and pacifier showed a trend towards lower scores compared with pacifiers alone. These simple and safe interventions should be widely used for minor procedures in neonates. Key messagesThe analgesic effects on newborn infants of sucrose, glucose, and pacifiers can be clearly detected by a behavioural pain rating scalePacifiers had a better analgesic effect than sweet solutionsA synergistic effect was found with a combination of sucrose and pacifiersSweet solutions and pacifiers constitute simple and safe interventions that can be used to provide analgesia in newborns during minor procedures PMID:10574854

  15. Sucrose octaacetate tasting in a heterogeneous population of CFW mice.

    PubMed

    Gannon, K S; Whitney, G

    1989-05-01

    Three experiments investigated the genetic underpinnings of the sucrose octaacetate (SOA) avoidance-indifference dimorphism that exists among outbred CFW mice. In the first experiment, results from 687 subjects across three generations of segregation were consistent with predictions from a single-autosomal, two-allele model, with dominance for the avoidance (Taster) phenotype. In the second experiment, heterogeneous CFW Tasters and Nontasters were mated with SWR/J (Taster) and C57BL/6J (Nontaster) inbred mice. The SWR and CFW mice are both derived from Swiss mice, and the results were consistent with the possibility that the Taster animals share an allele which is identical by descent. The second and third experiments also investigated sensitivity to SOA across an extended range of concentrations. Nontaster CFWs avoided SOA at the near-saturation 10(-3) M concentration but did not avoid any weaker concentrations. Taster CFWs avoided all concentrations down to approximately 10(-6) M SOA. PMID:2757593

  16. Study on the synthesis of sucrose-6-acetate catalyzed by fructosyltransferase from Aspergillus oryzae.

    PubMed

    Han, Yawei; Liu, Guoming; Huang, Dongye; Qiao, Baojian; Chen, Liping; Guan, Lihong; Mao, Duobin

    2011-01-31

    The study had mainly investigated the synthesis of sucrose-6-acetate (s-6-a) in fructosyltransferase action. The synthesis reaction of s-6-a was performed between sucrose and glucose-6-acetate (g-6-a), and identified by high performance liquid chromatography (HPLC). According to the reaction of s-6-a catalyzed by fructosyltransferase from Aspergillus oryzae, the effect factors of reaction, such as the ratio of g-6-a to sucrose, temperature, time, pH, substrate and enzyme concentration in the reaction, were investigated. All results indicated that the fructosyltransferase could catalyze the s-6-a synthesis, and the optimal conditions of fructosyltransferase in reaction were 50°C, pH 6.2, 48h reaction time, 60% sucrose, 1:3 ratio of g-6-a to sucrose and 4.0mg/L concentration of enzyme. This study plays the important role in sucralose synthesis, because it is very cumbersome in the reported methods. PMID:20643232

  17. Influence of sugars and hormones on the genes involved in sucrose metabolism in maize endosperms.

    PubMed

    Ren, X D; Liu, H M; Liu, Y H; Hu, Y F; Zhang, J J; Huang, Y B

    2015-01-01

    Starch is the major storage product in the endosperm of cereals. Its synthesis is closely related to sucrose metabolism. In our previous study, we found that the expression of most of the genes involved in starch synthesis might be regulated by sugars and hormones in the maize endosperm. However, little is known regarding the transcriptional regulation of genes involved in sucrose metabolism. Thus, in this study, maize endosperms were treated with different sugars and hormones and the expression of genes involved in sucrose metabolism (including synthesis, degradation, and transport) were evaluated using real-time quantitative reverse transcription-polymerase chain reaction. We found that genes affected by different sugars and hormones were primarily regulated by abscisic acid. Sucrose and abscisic acid showed an additive effect on the expression of some genes. Differences in the transcriptional regulation of genes involved in sucrose metabolism and starch biosynthesis were observed. PMID:25867309

  18. A Requirement for Sucrose in Xylem Sap Flow from Dormant Maple Trees 1

    PubMed Central

    Johnson, Robert W.; Tyree, Melvin T.; Dixon, Michael A.

    1987-01-01

    The response of excised stem segments of several tree species to freezing and thawing cycles was studied. All species studied (Thuja occidentalis, Fagus grandifolia, and Betula papyrifera) except maple (Acer spp.) exuded sap while freezing and absorbed on thawing. Maple stems absorbed sap while freezing and exuded sap during the thaw only when sucrose was present in the vessel solution. Increased concentration of sucrose in the vessel sap led to increased exudation. In the absence of sucrose, maple stems absorbed sap on thawing. The presence of sucrose enhanced sap absorption during freezing cycles in maples. In general, large sugars, disaccharides and larger, could substitute for sucrose in the maple exudation response while sugar hexoses could not. The results are discussed in relation to the O'Malley-Milburn model (1983 Can J Bot 61: 3100-3106) of sap flow in maples. Images Fig. 2 PMID:16665468

  19. A requirement for sucrose in xylem sap flow from dormant maple trees.

    PubMed

    Johnson, R W; Tyree, M T; Dixon, M A

    1987-06-01

    The response of excised stem segments of several tree species to freezing and thawing cycles was studied. All species studied (Thuja occidentalis, Fagus grandifolia, and Betula papyrifera) except maple (Acer spp.) exuded sap while freezing and absorbed on thawing. Maple stems absorbed sap while freezing and exuded sap during the thaw only when sucrose was present in the vessel solution. Increased concentration of sucrose in the vessel sap led to increased exudation. In the absence of sucrose, maple stems absorbed sap on thawing. The presence of sucrose enhanced sap absorption during freezing cycles in maples. In general, large sugars, disaccharides and larger, could substitute for sucrose in the maple exudation response while sugar hexoses could not. The results are discussed in relation to the O'Malley-Milburn model (1983 Can J Bot 61: 3100-3106) of sap flow in maples. PMID:16665468

  20. Red Yeast Rice: An Introduction

    MedlinePLUS

    ... drugs, and some may contain a potentially harmful contaminant. This fact sheet provides basic information about red ... supplements. Some red yeast rice products contain a contaminant called citrinin, which can cause kidney failure. Tell ...

  1. Interaction of metabolic stress with chronic mild stress in altering brain cytokines and sucrose preference.

    PubMed

    Remus, Jennifer L; Stewart, Luke T; Camp, Robert M; Novak, Colleen M; Johnson, John D

    2015-06-01

    There is growing evidence that metabolic stressors increase an organism's risk of depression. Chronic mild stress is a popular animal model of depression and several serendipitous findings have suggested that food deprivation prior to sucrose testing in this model is necessary to observe anhedonic behaviors. Here, we directly tested this hypothesis by exposing animals to chronic mild stress and used an overnight 2-bottle sucrose test (food ad libitum) on Day 5 and 10, then food and water deprive animals overnight and tested their sucrose consumption and preference in a 1-hr sucrose test the following morning. Approximately 65% of stressed animals consumed sucrose and showed a sucrose preference similar to nonstressed controls in an overnight sucrose test, and 35% showed a decrease in sucrose intake and preference. Following overnight food and water deprivation the previously "resilient" animals showed a significant decrease in sucrose preference and greatly reduced sucrose intake. In addition, we evaluated whether the onset of anhedonia following food and water deprivation corresponds to alterations in corticosterone, epinephrine, circulating glucose, or interleukin-1 beta (IL-1?) expression in limbic brain areas. Although all stressed animals showed adrenal hypertrophy and elevated circulating epinephrine, only stressed animals that were food deprived were hypoglycemic compared with food-deprived controls. Additionally, food and water deprivation significantly increased hippocampus IL-1? while food and water deprivation only increased hypothalamus IL-1? in stress-susceptible animals. These data demonstrate that metabolic stress of food and water deprivation interacts with chronic stressor exposure to induce physiological and anhedonic responses. (PsycINFO Database Record PMID:25914924

  2. Sucrose importation into laticifers of Hevea brasiliensis, in relation to ethylene stimulation of latex production

    PubMed Central

    Dusotoit-Coucaud, Anaïs; Brunel, Nicole; Kongsawadworakul, Panida; Viboonjun, Unchera; Lacointe, André; Julien, Jean-Louis; Chrestin, Hervé; Sakr, Soulaïman

    2009-01-01

    Background and Aims The major economic product of Hevea brasiliensis is a rubber-containing cytoplasm (latex), which flows out of laticifers (latex cells) when the bark is tapped. The latex yield is stimulated by ethylene. Sucrose, the unique precursor of rubber synthesis, must cross the plasma membrane through specific sucrose transporters before being metabolized in the laticifers. The relative importance of sucrose transporters in determining latex yield is unknown. Here, the effects of ethylene (by application of Ethrel®) on sucrose transporter gene expression in the inner bark tissues and latex cells of H. brasiliensis are described. Methods Experiments, including cloning sucrose transporters, real time RT-PCR and in situ hybridization, were carried out on virgin (untapped) trees, treated or untreated with the latex yield stimulant Ethrel. Key Results Seven putative full-length cDNAs of sucrose transporters were cloned from a latex-specific cDNA library. These transporters belong to all SUT (sucrose transporter) groups and differ by their basal gene expression in latex and inner soft bark, with a predominance of HbSUT1A and HbSUT1B. Of these sucrose transporters, only HbSUT1A and HbSUT2A were distinctly increased by ethylene. Moreover, this increase was shown to be specific to laticifers and to ethylene application. Conclusion The data and all previous information on sucrose transport show that HbSUT1A and HbSUT2A are related to the increase in sucrose import into laticifers, required for the stimulation of latex yield by ethylene in virgin trees. PMID:19567416

  3. Mössbauer studies on yeast metallothionein

    Microsoft Academic Search

    X.-Q. Ding; E. Bill; A. X. Trautwein; H. J. Hartmann; U. Weser

    1994-01-01

    Iron-substituted yeast metallothionein, Fe(II)-yeast-MT, has been studied by Mössbauer spectroscopy. The iron in the protein is in the high-spin ferrous state. As maximum metal content, 4 Fe(II)\\/molecule has been determined, with the 4 metal ions forming a diamagnetic cluster due to the antiferromagnetic exchange interaction between the Fe(II) ions via bridging thiolates. In case the iron titration is less than

  4. Sociobiology of the budding yeast.

    PubMed

    Wloch-Salamon, Dominika M

    2014-04-01

    Social theory has provided a useful framework for research with microorganisms. Here I describe the advantages and possible risks of using a well-known model organism, the unicellular yeast Saccharomyces cerevisiae, for sociobiological research. I discuss the problems connected with clear classification of yeast behaviour based on the fitnessbased Hamilton paradigm. Relevant traits include different types of communities, production of flocculins, invertase and toxins, and the presence of apoptosis. PMID:24736156

  5. Identification of actively filling sucrose sinks. [Solanum tuberosum; Phaseolus lunatus; Manihot esculenta; Liquidambar styraciflua L. ; Carya illinoinensis

    SciTech Connect

    Sung, Shijean S.; Xu, Dianpeng; Black C.C. (Univ. of Georgia, Athens (USA))

    1989-04-01

    Certain actively filling plant sucrose sinks such as a seed, a tuber, or a root can be identified by measuring the uridine diphosphate and pyrophosphate-dependent metabolism of sucrose. Sucrolysis in both active and quiescent sucrose sinks was tested and sucrose synthase was found to be the predominant sucrose breakdown activity. Sucrolysis via invertases was low and secondary in both types of sinks. Sucrose synthase activity dropped markedly, greater than fivefold, in quiescent sinks. The test are consistent with the hypothesis that the sucrose filling activity, i.e. the sink strength, of these plant sinks can be measured by testing the uridine diphosphate and pyrophosphate-dependent breakdown of sucrose. Measuring the initial reactions of sucrolysis shows much promise for use in agriculture crop and tree improvement research as a biochemical test for sink strength.

  6. Biotechnological Applications of Dimorphic Yeasts

    NASA Astrophysics Data System (ADS)

    Doiphode, N.; Joshi, C.; Ghormade, V.; Deshpande, M. V.

    The dimorphic yeasts have the equilibrium between spherical growth (budding) and polarized (hyphal or pseudohyphal tip elongation) which can be triggered by change in the environmental conditions. The reversible growth phenomenon has made dimorphic yeasts as an useful model to understand fungal evolution and fungal differentiation, in general. In nature dimorphism is clearly evident in plant and animal fungal pathogens, which survive and most importantly proliferate in the respective hosts. However, number of organisms with no known pathogenic behaviour also show such a transition, which can be exploited for the technological applications due to their different biochemical make up under different morphologies. For instance, chitin and chitosan production using dimorphic Saccharomyces, Mucor, Rhizopus and Benjaminiella, oil degradation and biotransformation with yeast-form of Yarrowia species, bioremediation of organic pollutants, exopolysac-charide production by yeast-phase of Aureobasidium pullulans, to name a few. Myrothecium verrucaria can be used for seed dressing in its yeast form and it produces a mycolytic enzyme complex in its hyphal-form for the biocontrol of fungal pathogens, while Beauveria bassiana and other entomopathogens kill the insect pest by producing yeast- like cells in the insect body. The form-specific expression of protease, chitinase, lipase, ornithine decarboxylase, glutamate dehydrogenases, etc. make Benjaminiella poitrasii, Basidiobolus sp., and Mucor rouxii strains important in bioremediation, nanobiotechnology, fungal evolution and other areas.

  7. Study of amyloids using yeast

    PubMed Central

    Wickner, Reed B.; Kryndushkin, Dmitry; Shewmaker, Frank; McGlinchey, Ryan; Edskes, Herman K.

    2012-01-01

    Summary Saccharomyces cerevisiae has been a useful model organism in such fields as the cell cycle, regulation of transcription, protein trafficking and cell biology, primarily because of its ease of genetic manipulation. This is no less so in the area of amyloid studies. The endogenous yeast amyloids described to date include prions, infectious proteins (Table 1), and some cell wall proteins (1). and amyloids of humans and a fungal prion have also been studied using the yeast system. Accordingly, the emphasis of this chapter will be on genetic, biochemical, cell biological and physical methods particularly useful in the study of yeast prions and other amyloids studied in yeast. We limit our description of these methods to those aspects which have been most useful in studying yeast prions, citing more detailed expositions in the literature. Volumes on yeast genetics methods (2–4), and on amyloids and prions (5, 6) are useful, and Masison has edited a volume of Methods on “Identification, analysis and characterization of fungal prions” which covers some of this territory (7). We also outline some useful physical methods, pointing the reader to more extensive and authoratative descriptions. PMID:22528100

  8. Characterization of the Highly Efficient Sucrose Isomerase from Pantoea dispersa UQ68J and Cloning of the Sucrose Isomerase Gene

    PubMed Central

    Wu, Luguang; Birch, Robert G.

    2005-01-01

    Sucrose isomerase (SI) genes from Pantoea dispersa UQ68J, Klebsiella planticola UQ14S, and Erwinia rhapontici WAC2928 were cloned and expressed in Escherichia coli. The predicted products of the UQ14S and WAC2928 genes were similar to known SIs. The UQ68J SI differed substantially, and it showed the highest isomaltulose-producing efficiency in E. coli cells. The purified recombinant WAC2928 SI was unstable, whereas purified UQ68J and UQ14S SIs were very stable. UQ68J SI activity was optimal at pH 5 and 30 to 35°C, and it produced a high ratio of isomaltulose to trehalulose (>22:1) across its pH and temperature ranges for activity (pH 4 to 7 and 20 to 50°C). In contrast, UQ14S SI showed optimal activity at pH 6 and 35°C and produced a lower ratio of isomaltulose to trehalulose (<8:1) across its pH and temperature ranges for activity. UQ68J SI had much higher catalytic efficiency; the Km was 39.9 mM, the Vmax was 638 U mg?1, and the Kcat/Km was 1.79 × 104 M?1 s?1, compared to a Km of 76.0 mM, a Vmax of 423 U mg?1, and a Kcat/Km of 0.62 × 104 M?1 s?1 for UQ14S SI. UQ68J SI also showed no apparent reverse reaction producing glucose, fructose, or trehalulose from isomaltulose. These properties of the P. dispersa UQ68J enzyme are exceptional among purified SIs, and they indicate likely differences in the mechanism at the enzyme active site. They may favor the production of isomaltulose as an inhibitor of competing microbes in high-sucrose environments, and they are likely to be highly beneficial for industrial production of isomaltulose. PMID:15746363

  9. Expression analysis of genes associated with sucrose accumulation in sugarcane (Saccharum spp. hybrids) varieties differing in content and time of peak sucrose storage.

    PubMed

    Chandra, A; Verma, P K; Islam, M N; Grisham, M P; Jain, R; Sharma, A; Roopendra, K; Singh, K; Singh, P; Verma, I; Solomon, S

    2015-05-01

    Sucrose synthesis/accumulation in sugarcane is a complex process involving many genes and regulatory sequences that control biochemical events in source-sink tissues. Among these, sucrose synthase (SuSy), sucrose phosphate synthase (SPS), soluble acid (SAI) and cell wall (CWI) invertases are important. Expression of these enzymes was compared in an early (CoJ64) and late (BO91) maturing sugarcane variety using end-point and qRT-PCR. Quantitative RT-PCR at four crop stages revealed high CWI expression in upper internodes of CoJ64, which declined significantly in both top and bottom internodes with maturity. In BO91, CWI expression was high in top and bottom internodes and declined significantly only in top internodes as the crop matured. Overall, CWI expression was higher in CoJ64 than in BO91. During crop growth, there was no significant change in SPS expression in bottom internodes in CoJ64, whereas in BO91 it decreased significantly. Apart from a significant decrease in expression of SuSy in mature bottom internodes of BO91, there was no significant change. Similar SAI expression was observed with both end-point and RT-PCR, except for significantly increased expression in top internodes of CoJ64 with maturity. SAI, being a major sucrose hydrolysing enzyme, was also monitored with end-point PCR expression in internode tissues of CoJ64 and BO91, with higher expression of SAI in BO91 at early crop stages. Enzyme inhibitors, e.g. manganese chloride (Mn(++) ), significantly suppressed expression of SAI in both early- and late-maturing varieties. Present findings enhance understanding of critical sucrose metabolic gene expression in sugarcane varieties differing in content and time of peak sucrose storage. Thus, through employing these genes, improvement of sugarcane sucrose content is possible. PMID:25311688

  10. COMPARISON OF SCUROSE CATABOLISM IN ROOTS OF THREE BETA VULGAR L GENOTYPES WITH DIFFERENT YIELD AND SUCROSE ACCUMULATING CAPACITIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sucrose catabolism is a major determinant of sink strength in nearly all plants and affects sucrose partitioning to growing sinks as well as sink size and carbohydrate content. Three major enzyme families are responsible for sucrose catabolism in sugarbeet roots: acid invertase, alkaline invertase ...

  11. Relative effects of cultivar, heat-treatment and sucrose content on the sensory properties of blackcurrant juice

    Microsoft Academic Search

    Rex M. Brennan; E. Anthony Hunter; D. Donald Muir

    2003-01-01

    The effects of processing treatments (heat, sucrose addition) on the sensory quality of blackcurrant juices prepared from two genetically diverse cultivars (Ben Lomond and Ben Alder) were examined using sensory profiling. Sucrose level had the largest effect on the sensory profile, with heating and cultivar having smaller but still significant effects. Some interaction between sucrose level and heating of the

  12. Survie des gamtes de truite Arc-en-ciel aprs dilution dans des solutions salines ou de sucrose

    E-print Network

    Boyer, Edmond

    Survie des gamètes de truite Arc-en-ciel après dilution dans des solutions salines ou de sucrose R of rainbow trout gametes after dilution in mineral or sucrose solutions. Ova or spermatozoa of the rainbow trout, Salmo gairdneri, were exposed during increasing time lengths to sucrose solutions (200

  13. Antimicrobial activity of Epilobium spp. extracts

    Microsoft Academic Search

    Lucia Battinelli; Beatrice Tita; Maria Grazia Evandri; Gabriela Mazzanti

    2001-01-01

    The antimicrobial activity of the Epilobium angustifolium, E. hirsutum, E. palustre, E. tetragonum and E. rosmarinifolium ethanolic extracts was studied in vitro on Gram-positive and Gram-negative bacteria, yeasts and fungi. The cytotoxicity of the extracts was also evaluated using the Artemia salina test. All the extracts showed antimicrobial activity in a range of concentrations between 10 and 650 ?g\\/ml of

  14. Distinct sucrose isomerases catalyze trehalulose synthesis in whiteflies, Bemisia argentifolii, and Erwinia rhapontici.

    PubMed

    Salvucci, Michael E

    2003-06-01

    Isomaltulose [alpha-D-glucopyranosyl-(1,6)-D-fructofuranose] and trehalulose [alpha-D-glucopyranosyl-(1,1)-D-fructofuranose] are commercially valuable sucrose-substitutes that are produced in several microorganisms by the palI gene product, a sucrose isomerase. Trehalulose also occurs in the silverleaf whitefly, Bemisia argentifoli, as the major carbohydrate in the insect's honeydew. To determine if the enzyme that synthesizes trehalulose in whiteflies was similar to the well-characterized sucrose isomerase from microbial sources, the properties of the enzymes from whiteflies and the bacterium, Erwinia rhapontici, were compared. Partial purification of both enzymes showed that the enzyme from whiteflies was a 116 kD membrane-associated polypeptide, in contrast to the enzyme from E. rhapontici, which was soluble and 66 kD. The enzyme from E. rhapontici converted sucrose to isomaltulose and trehalulose in a 5:1 ratio, whereas the enzyme from whiteflies produced only trehalulose. Unlike the E. rhapontici enzyme, the whitefly enzyme did not convert isomaltulose to trehalulose, but both enzymes catalyzed the transfer of fructose to trehalulose using sucrose as the glucosyl donor. The results indicate that trehalulose synthase from whiteflies is structurally and functionally distinct from the sucrose isomerases described in bacteria. The whitefly enzyme is the first reported case of an enzyme that converts sucrose to exclusively trehalulose. PMID:12798947

  15. Role of maltase in the utilization of sucrose by Candida albicans.

    PubMed

    Williamson, P R; Huber, M A; Bennett, J E

    1993-05-01

    Two isoenzymes of maltase (EC 3.2.1.20) were purified to homogeneity from Candida albicans. Isoenzymes I and II were found to have apparent molecular masses of 63 and 66 kDa on SDS/PAGE with isoelectric points of 5.0 and 4.6 respectively. Both isoenzymes resembled each other in similar N-terminal sequence, specificity for the alpha(1-->4) glycosidic linkage and immune cross-reactivity on Western blots using a maltase II antigen-purified rabbit antibody. Maltase was induced by growth on sucrose whereas beta-fructofuranosidase activity could not be detected under similar conditions. Maltase I and II were shown to be unglycosylated enzymes by neutral sugar assay, and more than 90% of alpha-glucosidase activity was recoverable from spheroplasts. These data, in combination with other results from this laboratory [Geber, Williamson, Rex, Sweeney and Bennett (1992) J. Bacteriol. 174, 6992-6996] showing lack of a plausible leader sequence in genomic or mRNA transcripts, suggest an intracellular localization of the enzyme. To establish further the mechanism of sucrose assimilation by maltase, the existence of a sucrose-inducible H+/sucrose syn-transporter was demonstrated by (1) the kinetics of sucrose-induced [14C]sucrose uptake, (2) recovery of intact [14C]sucrose from ground cells by t.l.c. and (3) transport of 0.83 mol of H+/mol of [14C]sucrose. In total, the above is consistent with a mechanism whereby sucrose is transported into C. albicans to be hydrolysed by an intracellular maltase. PMID:8489504

  16. Ultra-slow water diffusion in aqueous sucrose glasses.

    PubMed

    Zobrist, Bernhard; Soonsin, Vacharaporn; Luo, Bei P; Krieger, Ulrich K; Marcolli, Claudia; Peter, Thomas; Koop, Thomas

    2011-02-28

    We present measurements of water uptake and release by single micrometre-sized aqueous sucrose particles. The experiments were performed in an electrodynamic balance where the particles can be stored contact-free in a temperature and humidity controlled chamber for several days. Aqueous sucrose particles react to a change in ambient humidity by absorbing/desorbing water from the gas phase. This water absorption (desorption) results in an increasing (decreasing) droplet size and a decreasing (increasing) solute concentration. Optical techniques were employed to follow minute changes of the droplet's size, with a sensitivity of 0.2 nm, as a result of changes in temperature or humidity. We exposed several particles either to humidity cycles (between ?2% and 90%) at 291 K or to constant relative humidity and temperature conditions over long periods of time (up to several days) at temperatures ranging from 203 to 291 K. In doing so, a retarded water uptake and release at low relative humidities and/or low temperatures was observed. Under the conditions studied here, the kinetics of this water absorption/desorption process is controlled entirely by liquid-phase diffusion of water molecules. Hence, it is possible to derive the translational diffusion coefficient of water molecules, D(H(2)O,) from these data by simulating the growth or shrinkage of a particle with a liquid-phase diffusion model. Values for D(H(2)O)-values as low as 10(-24) m(2) s(-1) are determined using data at temperatures down to 203 K deep in the glassy state. From the experiment and modelling we can infer strong concentration gradients within a single particle including a glassy skin in the outer shells of the particle. Such glassy skins practically isolate the liquid core of a particle from the surrounding gas phase, resulting in extremely long equilibration times for such particles, caused by the strongly non-linear relationship between concentration and D(H(2)O). We present a new parameterization of D(H(2)O) that facilitates describing the stability of aqueous food and pharmaceutical formulations in the glassy state, the processing of amorphous aerosol particles in spray-drying technology, and the suppression of heterogeneous chemical reactions in glassy atmospheric aerosol particles. PMID:21229162

  17. Drying enhances immunoactivity of spent brewer's yeast cell wall ?-d-glucans.

    PubMed

    Liepins, Janis; Kova?ova, Elena; Shvirksts, Karlis; Grube, Mara; Rapoport, Alexander; Kogan, Grigorij

    2015-07-20

    Due to immunological activity, microbial cell wall polysaccharides are defined as 'biological response modifiers' (BRM). Cell walls of spent brewer's yeast also have some BRM activity. However, up to date there is no consensus on the use of spent brewer's yeast d-glucan as specific BRM in humans or animals. The aim of this paper is to demonstrate the potential of spent brewer's yeast ?-d-glucans as BRM, and drying as an efficient pretreatment to increase ?-d-glucan's immunogenic activity. Our results revealed that drying does not change spent brewer's yeast biomass carbohydrate content as well as the chemical structure of purified ?-d-glucan. However, drying increased purified ?-d-glucan TNF-? induction activity in the murine macrophage model. We presume drying pretreatment enhances purity of extracted ?-d-glucan. This is corroborated with FT-IR analyses of the ?-d-glucan spectra. Based on our results, we suggest that dry spent brewer's yeast biomass can be used as a cheap source for high-quality ?-d-glucan extraction. Drying in combination with carboxylmethylation (CM), endows spent brewer's yeast ?-d-glucan with the immunoactivity similar or exceeding that of a well-characterized fungal BRM pleuran. PMID:25858155

  18. Coherent regulation in yeast’s cell-cycle network

    NASA Astrophysics Data System (ADS)

    Aral, Ne?e; Kabakç?o?lu, Alkan

    2015-05-01

    We define a measure of coherent activity for gene regulatory networks, a property that reflects the unity of purpose between the regulatory agents with a common target. We propose that such harmonious regulatory action is desirable under a demand for energy efficiency and may be selected for under evolutionary pressures. We consider two recent models of the cell-cycle regulatory network of the yeast, Saccharomyces cerevisiae as a case study and calculate their degree of coherence. A comparison with random networks of similar size and composition reveals that the yeast’s cell-cycle regulation is wired to yield an exceptionally high level of coherent regulatory activity. We also investigate the mean degree of coherence as a function of the network size, connectivity and the fraction of repressory/activatory interactions.

  19. Modeling of sucrose crystallization kinetics: The influence of glucose and fructose

    NASA Astrophysics Data System (ADS)

    Ouiazzane, S.; Messnaoui, B.; Abderafi, S.; Wouters, J.; Bounahmidi, T.

    2008-07-01

    The dynamic model developed in previous work [Ouiazzane et al., J. Crystal Growth 310 (2008) 798] for a batch crystallizer, was extended for studying the influence of glucose and of fructose on the crystallization kinetics of sucrose. Experimental data were obtained for each studied system by using a linear cooling profile. A nonlinear optimization method was employed to fit the kinetic parameters. The predicted results related to the mass of sucrose crystal were in agreement with the measured data. The influence of glucose and fructose on the crystallization of sucrose in a batch crystallizer is discussed herein.

  20. Nuclear Transport of Yeast Proteasomes

    PubMed Central

    Enenkel, Cordula

    2014-01-01

    Proteasomes are conserved protease complexes enriched in the nuclei of dividing yeast cells, a major site for protein degradation. If yeast cells do not proliferate and transit to quiescence, metabolic changes result in the dissociation of proteasomes into proteolytic core and regulatory complexes and their sequestration into motile cytosolic proteasome storage granuli. These granuli rapidly clear with the resumption of growth, releasing the stored proteasomes, which relocalize back to the nucleus to promote cell cycle progression. Here, I report on three models of how proteasomes are transported from the cytoplasm into the nucleus of yeast cells. The first model applies for dividing yeast and is based on the canonical pathway using classical nuclear localization sequences of proteasomal subcomplexes and the classical import receptor importin/karyopherin ??. The second model applies for quiescent yeast cells, which resume growth and use Blm10, a HEAT-like repeat protein structurally related to karyopherin ?, for nuclear import of proteasome core particles. In the third model, the fully-assembled proteasome is imported into the nucleus. Our still marginal knowledge about proteasome dynamics will inspire the discussion on how protein degradation by proteasomes may be regulated in different cellular compartments of dividing and quiescent eukaryotic cells. PMID:25333764

  1. 280 EXPRESSION IN YEAST [23] [23] Manipulating Yeast Genome Using Plasmid Vectors

    E-print Network

    Botstein, David

    280 EXPRESSION IN YEAST [23] [23] Manipulating Yeast Genome Using Plasmid Vectors By TIM STEARNS, HONG MA, and DAVID BOTSTEIN The yeast Saccharomyces cerevisiae has proved to be a popular high status of yeast as an experimental system is in large part due to the work of the many geneticists

  2. Pre-Absorbing Antibody with Yeast Cells Preparation of Fixed Yeast

    E-print Network

    Aris, John P.

    106 Pre-Absorbing Antibody with Yeast Cells Preparation of Fixed Yeast 1. Plan to do steps 1-10 in the yeast immunofluorescence method. But, start with 100 mls of cells at OD600=0.2. Then, do all steps in quadruplicate. Do pretreatment, and digest cells for 10 minutes. 2. Pool all yeast in SPC + Pics in one

  3. Yeast through the ages: A statistical analysis of genetic changes in aging yeast

    E-print Network

    Hardin, Jo

    Yeast through the ages: A statistical analysis of genetic changes in aging yeast A. Wise J. Hardin focuses on the analysis of data from a yeast DNA microarray experiment. The biological question that motivates our research is "What genetic changes in yeast happen over time?" In order to explore the research

  4. APPENDIX 4LGrowth and Manipulation of Yeast PREPARATION OF SELECTED YEAST MEDIA

    E-print Network

    Winston, Fred

    containers in which 2.5 kg of dextrose is packaged. Throughout this chapter, YNB -AA/AS refers to yeastAPPENDIX 4LGrowth and Manipulation of Yeast PREPARATION OF SELECTED YEAST MEDIA Like Escherichia coli, yeast can be grown in either liquid media or on the surface of (or embedded in) solid agar plates

  5. Interplay between sucrose and folate modulates auxin signaling in Arabidopsis.

    PubMed

    Stokes, Michael E; Chattopadhyay, Abhishek; Wilkins, Olivia; Nambara, Eiji; Campbell, Malcolm M

    2013-07-01

    As sessile organisms growing in an ever-changing environment, plants must integrate multiple regulatory inputs to promote the appropriate developmental responses. One such nutritional signal is cellular sugar levels, which rise and fall throughout the day and affect a variety of developmental processes. To uncover signaling pathways that modulate sugar perception, compounds from the Library of Active Compounds in Arabidopsis were screened for the ability to perturb developmental responses to sucrose (Suc) in Arabidopsis (Arabidopsis thaliana) seedlings. This screen found that sulfonamides, which inhibit folate biosynthesis in plants, restrict hypocotyl elongation in a sugar-dependent fashion. Transcriptome analysis identified a small set of transcripts that respond to the interaction between sulfonamide and Suc, including a number of transcripts encoding Auxin/Indole-3-Acetic Acids, negative regulators of auxin signal transduction. Chemical inhibition of auxin transport or genetic disruption of auxin signaling relieved this interaction, suggesting that responses to these two nutritional stimuli are mediated by auxin. Reporter systems used to track auxin signaling and distribution showed enhanced activity in the vascular region of the hypocotyl in response to cotreatment of Suc and sulfonamide, yet no change in auxin abundance was observed. Taken together, these findings suggest that the interplay between Suc and folates acts to fine-tune auxin sensitivity and influences auxin distribution during seedling development. PMID:23690535

  6. Sucrose polyester and plasma carotenoid concentrations in healthy subjects.

    PubMed

    Weststrate, J A; van het Hof, K H

    1995-09-01

    A double-blind, placebo-controlled crossover study of the effects of the nonabsorbable fat analogue sucrose polyester (SPE; 12.4 g/d) on plasma concentrations of five different carotenoids and vitamin E in 21 volunteers, and a double-blind, placebo-controlled parallel comparison study in 53 subjects of the effect of 3 g SPE/d on plasma concentrations of two different carotenoids were undertaken. SPE-containing margarine added to the main meal was used. SPE (12.4 g/d) reduced plasma of beta-carotene concentrations by 0.13 mumol/L (34%, P = 0.0001) and concentrations of lycopene by 0.14 mumol/L (52%, P = 0.0001). Smaller but significant reductions were found for plasma concentrations of beta-cryptoxanthin, lutein, zeaxanthin, and vitamin E. SPE (3 g/d) reduced plasma concentrations of beta-carotene by 0.094 mumol/L (20% P = 0.0001) and concentrations of lycopene by 0.12 mumol/L (38%, P = 0.0001). Even at low doses, SPE strongly reduces plasma carotenoid concentrations. This finding merits careful consideration in assessing the long-term health effects of SPE-containing consumer foods. PMID:7661121

  7. Voltage Clamp of Cardiac Muscle in a Double Sucrose Gap

    PubMed Central

    Harrington, Lesley; Johnson, Edward A.

    1973-01-01

    A method of stabilizing the membrane potential of a small area of cardiac muscle membrane and the limitations of this method are described. Tiny bundles or strands, approximately 80 ?m in diameter, of electrically interconnected fibers from the ventricles of rabbit hearts were used in a double sucrose gap. Current records associated with step changes in voltage were complicated by two capacitive surges of current of nodal and nonnodal origin and large “leakage” currents of nonnodal origin resulting mainly from the multifibered nature of the preparation and emphasized by the method. The transient, inward membrane currents in response to moderate depolarizing steps in command potential had the same duration as the upstroke of the action potential. In good runs, currents were smooth and free from notches. These initial currents behaved qualitatively like the initial sodium currents in squid axon and in other excitable membranes. A fraction of the initial sodium current persisted at least as long as 300 ms. The relationship between peak initial current and voltage was graded and linear in the positive direction. In the negative region the relationship was often very steep, indicating insufficient voltage control of all the membranes despite the squareness of the voltage record. Other indications of inadequacy of control could occur and thus even with this optimum preparation of cardiac muscle it was not feasible to analyze quantitatively either the initial or the prolonged sodium currents. PMID:4715582

  8. Bacteria, Yeast and Chemicals on Human Skin

    MedlinePLUS

    ... gov/medlineplus/videos/news/Microbes_040115-1.html Bacteria, Yeast and Chemicals on Human Skin HealthDay News ... on this page, please enable JavaScript. Play video: Bacteria, Yeast and Chemicals on Human Skin For closed ...

  9. Yeast Can Affect Behavior and Learning.

    ERIC Educational Resources Information Center

    Crook, William G.

    1984-01-01

    A pediatrician recounts his experiences in diagnosing and treating allergies to common yeast germs that may result in behavior and learning problems. He lists characteristics that may predispose children to yeast-connected health problems. (CL)

  10. On the use of sodium hexametaphosphate to extract spores of arbuscular mycorrhizal fungi from soil

    Microsoft Academic Search

    Pierre-Luc Chagnon; Robert L. Bradley

    2011-01-01

    Extraction of arbuscular mycorrhizal fungal (AMF) spores from soil is widely used to assess AMF community structure and abundance. The most widely used protocol relies on a water-sucrose gradient flotation technique. Na-hexametaphosphate has also been used to deflocculate soil aggregates prior to spore extraction in order to optimize recovery, but its effect on spore viability remains unknown. Here, we report

  11. Characterization of the highly efficient sucrose isomerase from Pantoea dispersa UQ68J and cloning of the sucrose isomerase gene.

    PubMed

    Wu, Luguang; Birch, Robert G

    2005-03-01

    Sucrose isomerase (SI) genes from Pantoea dispersa UQ68J, Klebsiella planticola UQ14S, and Erwinia rhapontici WAC2928 were cloned and expressed in Escherichia coli. The predicted products of the UQ14S and WAC2928 genes were similar to known SIs. The UQ68J SI differed substantially, and it showed the highest isomaltulose-producing efficiency in E. coli cells. The purified recombinant WAC2928 SI was unstable, whereas purified UQ68J and UQ14S SIs were very stable. UQ68J SI activity was optimal at pH 5 and 30 to 35 degrees C, and it produced a high ratio of isomaltulose to trehalulose (>22:1) across its pH and temperature ranges for activity (pH 4 to 7 and 20 to 50 degrees C). In contrast, UQ14S SI showed optimal activity at pH 6 and 35 degrees C and produced a lower ratio of isomaltulose to trehalulose (<8:1) across its pH and temperature ranges for activity. UQ68J SI had much higher catalytic efficiency; the Km was 39.9 mM, the Vmax was 638 U mg(-1), and the Kcat/Km was 1.79 x 10(4) M(-1) s(-1), compared to a Km of 76.0 mM, a Vmax of 423 U mg(-1), and a Kcat/Km of 0.62 x 10(4) M(-1) s(-1) for UQ14S SI. UQ68J SI also showed no apparent reverse reaction producing glucose, fructose, or trehalulose from isomaltulose. These properties of the P. dispersa UQ68J enzyme are exceptional among purified SIs, and they indicate likely differences in the mechanism at the enzyme active site. They may favor the production of isomaltulose as an inhibitor of competing microbes in high-sucrose environments, and they are likely to be highly beneficial for industrial production of isomaltulose. PMID:15746363

  12. Cytosolic Hsp60 can modulate proteasome activity in yeast.

    PubMed

    Kalderon, Bella; Kogan, Gleb; Bubis, Ettel; Pines, Ophry

    2015-02-01

    Hsp60, an essential oligomeric molecular mitochondrial chaperone, has been subject to rigorous basic and clinical research. With yeast as a model system, we provide evidence for the ability of cytosolic yHsp60 to inhibit the yeast proteasome. (i) Following biological turnover of murine Bax (a proteasome substrate), we show that co-expression of cytosolic yHsp60 stabilizes Bax, enhances its association with mitochondria, and enhances its killing capacity. (ii) Expression of yHsp60 in the yeast cytosol (yHsp60c) inhibits degradation of a cytosolic protein ?MTS-Aco1 tagged with the degron SL17 (a ubiquitin-proteasome substrate). (iii) Conditions under which Hsp60 accumulates in the cytosol (elevated Hsp60c or growth at 37 °C) correlate with reduced 20 S peptidase activity in proteasomes purified from cell extracts. (iv) Elevated yHsp60 in the cytosol correlate with accumulation of polyubiquitinated proteins. (v) According to 20 S proteasome pulldown experiments, Hsp60 is physically associated with proteasomes in extracts of cells expressing Hsp60c or grown at 37 °C. Even mutant Hsp60 proteins, lacking chaperone activity, were still capable of proteasome inhibition. The results support the hypothesis that localization of Hsp60 to the cytosol may modulate proteasome activity according to cell need. PMID:25525272

  13. Cdc42 Oscillations in Yeasts

    NSDL National Science Digital Library

    Felipe O. Bendezu (Switzerland; University of Lausanne REV)

    2012-12-04

    A fundamental problem in cell biology is how cells define one or several discrete sites of polarity. Through mechanisms involving positive and negative feedback, the small Rho-family guanosine triphosphatase Cdc42 breaks symmetry in round budding yeast cells to define a single site of polarized cell growth. However, it is not clear how cells can define multiple sites of polarization concurrently. We discuss a study in which rod-shaped fission yeast cells, which naturally polarize growth at their two cell ends, exhibited oscillations of Cdc42 activity between these sites. We compare these findings with similar oscillatory behavior of Cdc42 detected in budding yeast cells and discuss the possible mechanism and functional outputs of these oscillations.

  14. Yeast proteome map (update 2006).

    PubMed

    Perrot, Michel; Guieysse-Peugeot, Anne-Laure; Massoni, Aurélie; Espagne, Christelle; Claverol, Stéphane; Silva, Raquel Monteiro; Jenö, Paul; Santos, Manuel; Bonneu, Marc; Boucherie, Hélian

    2007-04-01

    To improve the potential of two-dimensional gel electrophoresis for proteomic investigations in yeast we have undertaken the systematic identification of Saccharomyces cerevisiae proteins separated on 2-D gels. We report here the identification of 187 novel protein spots. They were identified by two methods, mass spectrometry and gene inactivation. These identifications extend the number of protein spots identified on our yeast 2-D proteome map to 602, i.e. nearly half the detectable spots of the proteome map. These spots correspond to 417 different proteins. The reference map and the list of identified proteins can be accessed on the Yeast Protein Map server (www.ibgc.u-bordeaux2.fr/YPM). PMID:17351888

  15. Antimicrobial activity of Wedelia trilobata crude extracts.

    PubMed

    Taddei, A; Rosas-Romero, A J

    1999-05-01

    A biological screening of activity against Gram-positive and Gram-negative bacteria, yeasts, and fungi of crude extracts from Wedelia trilobata is reported. The n-hexane extract showed antibacterial activity against Bacillus subtilis, Mycobacterium smegmatis, Staphylococcus aureus, and Staphylococcus epidermidis (Gram-positive bacteria); along with Proteus vulgaris, Pseudomonas aeruginosa, Salmonella group C, Salmonella paratyphi, and Shigella sonnei (Gram-negative bacteria). The ethyl acetate extract was active only against Salmonella group C; and the aqueous extract was inactive against the tested bacteria. None of the tested extracts showed biological activity against the yeasts (Candida albicans, Candida tropicalis, Rhodotorula rubra) or the fungi (Aspergillus flavus, Aspergillus niger, Mucor sp., Trichophyton rubrum). PMID:10374253

  16. Sporulation of the yeast Saccharomyces cerevisiae is accompanied by synthesis of adenosine 5'-tetraphosphate and adenosine 5'-pentaphosphate.

    PubMed Central

    Jakubowski, H

    1986-01-01

    Two-dimensional TLC analysis of 32P-labeled nucleotides extracted from the yeast Saccharomyces cerevisiae reveals that two highly phosphorylated nucleotides are synthesized during sporulation. These nucleotides have been identified as adenosine 5'-tetraphosphate (ppppA) and adenosine 5'-pentaphosphate (pppppA). The synthesis of ppppA and pppppA commences late in sporulation and follows formation of ascospores. The maximum concentration of ppppA and pppppA in sporulating yeast cultures was 2% and 1.5%, respectively, that of ATP. Adenosine 5'-tetraphosphate and 5'-pentaphosphate are unique to this stage of yeast development and are absent in vegetative yeast cells. Since these nucleotides are also absent in asporogenous a/a and alpha/alpha cells, it is reasonable to propose that they are signal nucleotides marking one of the stages of yeast development--i.e., ascospore formation. Images PMID:3517867

  17. Microplate assay for rapid determination of sucrose, glucose, fructose and raffinose

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current methods for the quantification of carbohydrates in sugarbeet roots have limitations. Polarimetry and refractometry measure only sucrose content and are inaccurate with deteriorated roots. High performance liquid chromatography (HPLC) and gas chromatography (GC) quantify all simple carbohy...

  18. The interaction of temperature and sucrose concentration on foraging preferences in bumblebees

    NASA Astrophysics Data System (ADS)

    Whitney, Heather M.; Dyer, Adrian; Chittka, Lars; Rands, Sean A.; Glover, Beverley J.

    2008-09-01

    Several authors have found that flowers that are warmer than their surrounding environment have an advantage in attracting pollinators. Bumblebees will forage preferentially on warmer flowers, even if equal nutritional reward is available in cooler flowers. This raises the question of whether warmth and sucrose concentration are processed independently by bees, or whether sweetness detectors respond to higher sugar concentration as well as higher temperature. We find that bumblebees can use lower temperature as a cue to higher sucrose reward, showing that bees appear to process the two parameters strictly independently. Moreover, we demonstrate that sucrose concentration takes precedence over warmth, so that when there is a difference in sucrose concentration, bees will typically choose the sweeter feeder, even if the less sweet feeder is several degrees warmer.

  19. Mutations inducing an active-site aperture in Rhizobium sp. sucrose isomerase confer hydrolytic activity.

    PubMed

    Lipski, Alexandra; Watzlawick, Hildegard; Ravaud, Stéphanie; Robert, Xavier; Rhimi, Moez; Haser, Richard; Mattes, Ralf; Aghajari, Nushin

    2013-02-01

    Sucrose isomerase is an enzyme that catalyzes the production of sucrose isomers of high biotechnological and pharmaceutical interest. Owing to the complexity of the chemical synthesis of these isomers, isomaltulose and trehalulose, enzymatic conversion remains the preferred method for obtaining these products. Depending on the microbial source, the ratio of the sucrose-isomer products varies significantly. In studies aimed at understanding and explaining the underlying molecular mechanisms of these reactions, mutations obtained using a random-mutagenesis approach displayed a major hydrolytic activity. Two of these variants, R284C and F164L, of sucrose isomerase from Rhizobium sp. were therefore crystallized and their crystal structures were determined. The three-dimensional structures of these mutants allowed the identification of the molecular determinants that favour hydrolytic activity compared with transferase activity. Substantial conformational changes resulting in an active-site opening were observed, as were changes in the pattern of water molecules bordering the active-site region. PMID:23385465

  20. Sucrose (table sugar) permeability as a diagnostic test for equine gastric ulcers

    E-print Network

    O'Conor, Michael

    2002-01-01

    The prevalence of gastric ulceration in horses is high, often reaching 90% depending on population and level of training. Endoscopic examination is the only means of definitive diagnosis. The hypothesis of this study was that urinary sucrose...

  1. Red yeast rice: a new hypolipidemic drug

    Microsoft Academic Search

    Mélanie Journoud; Peter J. H Jones

    2004-01-01

    Red yeast rice is a source of fermented pigment with possible bioactive effect. Evidence shows that fermented red yeast rice lowers cholesterol levels moderately compared to other statin drugs, but with the added advantage of causing less adverse effects. A review of the body of evidence surrounding the properties of red yeast rice underscores its potential as a new alternative

  2. Enological functions of parietal yeast mannoproteins

    Microsoft Academic Search

    Andrea Caridi

    2006-01-01

    Parietal yeast mannoproteins play a very important role in the overall vinification process. Their production and release, both during winemaking and aging on lees, depends on the specific yeast strain and the nutritional conditions. The following enological functions of parietal yeast mannoproteins have been described: (a) adsorption of ochratoxin A; (b) combination with phenolic compounds; (c) increased growth of malolactic

  3. YEASTBOOK PERSPECTIVES Yeast: An Experimental Organism

    E-print Network

    Botstein, David

    YEASTBOOK PERSPECTIVES Yeast: An Experimental Organism for 21st Century Biology David Botstein*,1, Cambridge, Massachusetts 02139 ABSTRACT In this essay, we revisit the status of yeast as a model system for biology. We first summarize important contributions of yeast to eukaryotic biology that we anticipated

  4. Yeast: A Research Organism for Teaching Genetics.

    ERIC Educational Resources Information Center

    Manney, Thomas R.; Manney, Monta L.

    1992-01-01

    Explains why laboratory strains of bakers yeast, Saccharomyces cerevisiae, are particularly suited for classroom science activities. Describes the sexual life cycle of yeast and the genetic system with visible mutations. Presents an overview of activities that can be done with yeast and gives a source for teachers to obtain more information. (PR)

  5. Mössbauer studies on yeast metallothionein

    NASA Astrophysics Data System (ADS)

    Ding, X.-Q.; Bill, E.; Trautwein, A. X.; Hartmann, H. J.; Weser, U.

    1994-12-01

    Iron-substituted yeast metallothionein, Fe(II)-yeast-MT, has been studied by Mössbauer spectroscopy. The iron in the protein is in the high-spin ferrous state. As maximum metal content, 4 Fe(II)/molecule has been determined, with the 4 metal ions forming a diamagnetic cluster due to the antiferromagnetic exchange interaction between the Fe(II) ions via bridging thiolates. In case the iron titration is less than 4 Fe(II)/apoprotein, the ions are magnetically noninteracting, with each individual Fe(II) behaving similar to Fe(II) in reduced rubredoxin.

  6. Combined nuclear measurements of yeast

    NASA Astrophysics Data System (ADS)

    Saleh, N. S.; Al-Saleh, K. A.; Arafah, D.-E.; Halim, N. A.

    1987-05-01

    Combined Rutherford backscattering (RBS), X-ray fluorescence (XRF) and proton induced X-ray emission (PIXE) techniques were used to determine the elemental composition of yeast. Results reveal no toxic elements (e.g. Ag, Pb, etc) in yeast. Yet results display some similarities in concentrations of some elements (e.g. Ti, Mn, Ni, Cu and Sr), large differences are observed for others (e.g. S, Cl, K, Ca, Fe and Zn). Variations are accounted due to different growing media or contamination during processing.

  7. Beer brewing using a fusant between a sake yeast and a brewer's yeast

    Microsoft Academic Search

    Nobuhiko Mukai; Chiharu Nishimori; Ikuko Wilson Fujishige; Akihiro Mizuno; Toshiro Takahashi; Kazuo Sato

    2001-01-01

    Beer brewing using a fusant between a sake yeast (a lysine auxotrophic mutant of sake yeast K-14) and a brewer's yeast (a respiratory-deficient mutant of the top fermentation yeast NCYC1333) was performed to take advantage of the beneficial characteristics of sake yeasts, i.e., the high productivity of esters, high tolerance to ethanol, and high osmotolerance. The fusant (F-32) obtained was

  8. Toxicity and repellency of borate-sucrose water baits to Argentine ants (Hymenoptera: Formicidae).

    PubMed

    Klotz, J H; Greenberg, L; Amrhein, C; Rust, M K

    2000-08-01

    The oral toxicity of boron compounds to the Argentine ant, Linepithema humile (Mayr), was evaluated in laboratory tests. The ants were provided 25% sucrose water containing 0.5 and 1% boric acid, disodium octaborate tetrahydrate, and borax. Lethal times of these solutions were a function of the concentration of boron. In field tests, the ants showed no discrimination between disodium octaborate tetrahydrate and boric acid. There was a significant reduction in consumption of sucrose water with > 1% boric acid. PMID:10985039

  9. Effect of temperature and sucrose concentration on hydroquinone toxicity in leafy spurge suspension culture cells.

    PubMed

    Hogan, M E; Manners, G D

    1992-09-01

    Euphorbia esula (leafy spurge) suspension culture cell bioassays were used to determine whether sucrose accumulation enhanced the glucosylation (detoxification) of hydroquinone in this noxious weed. The bioassay results indicate that cold temperatures and exogenous hydroquinone represent a dual stress to spurge cell growth that can be partially ameliorated by hydrolysis of sucrose. The persistent susceptibility of leafy spurge suggests that hydroquinone-producing forage plants (which are not toxic to animals) might be used as natural competitors. PMID:24254285

  10. EQUILIBRIUM CONCENTRATION AND WATER AND SUCROSE DIFFUSIVITY IN OSMOTIC DEHYDRATION OF PINEAPPLE SLABS

    Microsoft Academic Search

    K. N. Waliszewski; J. L. Delgado; M. A. García

    2002-01-01

    The weight and water loss of 6 mm thick pineapple slabs (one of a six part of slice) were analyzed during osmotic dehydration in sucrose solution at different temperatures (50, 60 and 70°C), sucrose concentrations (50, 60 and 70°Bx) and pH's (6, 7 and 8), in 3 experimental design. These results were fitted to a modified Azuara equation to obtain water

  11. Sucrose-induced vacuolation results in increased expression of cholesterol biosynthesis and lysosomal genes

    Microsoft Academic Search

    Amanda Helip-Wooley; Jess G Thoene

    2004-01-01

    Mammalian cells cultured in the presence of high concentrations of sucrose demonstrate large, phase-lucent, osmotically swollen vacuoles. Three normal human fibroblast cell lines exposed to 100 mM of sucrose for 24 h demonstrated increased expression of lysosomal, intracellular vesicle trafficking, cholesterol biosynthesis, and fatty acid metabolism genes. Most steps of the cholesterol biosynthesis pathway were upregulated including HMG CoA reductase,

  12. Synthesis and luminescence of europium doped yttria nanophosphors via a sucrose-templated combustion method

    Microsoft Academic Search

    Lingling Xu; Bo Wei; Zhiguo Zhang; Zhe Lü; Hong Gao; Yungang Zhang

    2006-01-01

    Nanocrystalline Y2O3:Eu phosphors have been successfully synthesized by a novel combustion method using sucrose as a chelating agent and fuel. The sucrose hydrolysation and complexing mechanisms are discussed. X-ray diffraction analysis showed that the cubic phase can be formed at a low temperature of 400 °C, and transmission electron microscopy observations revealed that the phosphor particles were 30-50 nm annealed

  13. Sucrose exposure in early life alters adult motivation and weight gain.

    PubMed

    Frazier, Cristianne R M; Mason, Peggy; Zhuang, Xiaoxi; Beeler, Jeff A

    2008-01-01

    The cause of the current increase in obesity in westernized nations is poorly understood but is frequently attributed to a 'thrifty genotype,' an evolutionary predisposition to store calories in times of plenty to protect against future scarcity. In modern, industrialized environments that provide a ready, uninterrupted supply of energy-rich foods at low cost, this genetic predisposition is hypothesized to lead to obesity. Children are also exposed to this 'obesogenic' environment; however, whether such early dietary experience has developmental effects and contributes to adult vulnerability to obesity is unknown. Using mice, we tested the hypothesis that dietary experience during childhood and adolescence affects adult obesity risk. We gave mice unlimited or no access to sucrose for a short period post-weaning and measured sucrose-seeking, food consumption, and weight gain in adulthood. Unlimited access to sucrose early in life reduced sucrose-seeking when work was required to obtain it. When high-sugar/high-fat dietary options were made freely-available, however, the sucrose-exposed mice gained more weight than mice without early sucrose exposure. These results suggest that early, unlimited exposure to sucrose reduces motivation to acquire sucrose but promotes weight gain in adulthood when the cost of acquiring palatable, energy dense foods is low. This study demonstrates that early post-weaning experience can modify the expression of a 'thrifty genotype' and alter an adult animal's response to its environment, a finding consistent with evidence of pre- and peri-natal programming of adult obesity risk by maternal nutritional status. Our findings suggest the window for developmental effects of diet may extend into childhood, an observation with potentially important implications for both research and public policy in addressing the rising incidence of obesity. PMID:18797507

  14. ROLE OF INITIAL SUCROSE AND PH LEVELS ON NATURAL, HYDROGEN-PRODUCING, ANAEROBE GERMINATION

    Microsoft Academic Search

    Steven Van Ginkel; ShihWu Sung; Ling Li

    2001-01-01

    Anaerobic batch cultures were established to assess natural anaerobic sporulation, germination, and hydrogen production. Heat-shocked soil inocula obtained from a potato field was cultured using sucrose as the substrate. Eleven batch experimental results suggested that baking was an excellent heat-shock treatment to select for spore forming hydrogen-producing bacteria i.e. clostridia from the soil. Sucrose could induce clostridial spore germination and

  15. Large-scale analysis of membrane transport in yeast using invertase reporters.

    PubMed

    Dalton, Lauren; Davey, Michael; Conibear, Elizabeth

    2015-01-01

    Transport of membrane proteins between cellular organelles requires the concerted action of many regulatory factors, which aid in cargo recognition and vesicle formation, targeting, and fusion. The yeast Saccharomyces cerevisiae is a useful model system for studying such regulators, due to the availability of genome-wide mutant collections and reporter proteins that provide sensitive biochemical readouts of individual transport pathways. Here, we describe an enzymatic invertase assay for evaluating endocytic recycling using a chimeric GFP-Snc1-Suc2 reporter. Cell surface levels of this reporter can be measured by a colorimetric assay that monitors sucrose hydrolysis at the plasma membrane, using two different methods. The first is a semiquantitative agar overlay assay followed by image densitometry that is suitable for high-throughput screening of arrayed yeast colonies. In the second, more quantitative assay, an enzymatic solution is added to yeast cultures in a multi-well plate and the absorbance is assessed by a plate reader. Furthermore, the modular nature of the chimeric reporter allows alternate transport signals to be introduced, thereby expanding the range of transport pathways that can be evaluated by this method. Together these techniques can be used to explore the function of genes involved in a variety of cellular trafficking pathways. PMID:25702131

  16. Saccharomyces Genome Database: the genomics resource of budding yeast

    PubMed Central

    Cherry, J. Michael; Hong, Eurie L.; Amundsen, Craig; Balakrishnan, Rama; Binkley, Gail; Chan, Esther T.; Christie, Karen R.; Costanzo, Maria C.; Dwight, Selina S.; Engel, Stacia R.; Fisk, Dianna G.; Hirschman, Jodi E.; Hitz, Benjamin C.; Karra, Kalpana; Krieger, Cynthia J.; Miyasato, Stuart R.; Nash, Rob S.; Park, Julie; Skrzypek, Marek S.; Simison, Matt; Weng, Shuai; Wong, Edith D.

    2012-01-01

    The Saccharomyces Genome Database (SGD, http://www.yeastgenome.org) is the community resource for the budding yeast Saccharomyces cerevisiae. The SGD project provides the highest-quality manually curated information from peer-reviewed literature. The experimental results reported in the literature are extracted and integrated within a well-developed database. These data are combined with quality high-throughput results and provided through Locus Summary pages, a powerful query engine and rich genome browser. The acquisition, integration and retrieval of these data allow SGD to facilitate experimental design and analysis by providing an encyclopedia of the yeast genome, its chromosomal features, their functions and interactions. Public access to these data is provided to researchers and educators via web pages designed for optimal ease of use. PMID:22110037

  17. Sucrose-induced Receptor Kinase SIRK1 Regulates a Plasma Membrane Aquaporin in Arabidopsis*

    PubMed Central

    Wu, Xu Na; Sanchez Rodriguez, Clara; Pertl-Obermeyer, Heidi; Obermeyer, Gerhard; Schulze, Waltraud X.

    2013-01-01

    The transmembrane receptor kinase family is the largest protein kinase family in Arabidopsis, and it contains the highest fraction of proteins with yet uncharacterized functions. Here, we present functions of SIRK1, a receptor kinase that was previously identified with rapid transient phosphorylation after sucrose resupply to sucrose-starved seedlings. SIRK1 was found to be an active kinase with increasing activity in the presence of an external sucrose supply. In sirk1 T-DNA insertional mutants, the sucrose-induced phosphorylation patterns of several membrane proteins were strongly reduced; in particular, pore-gating phosphorylation sites in aquaporins were affected. SIRK1-GFP fusions were found to directly interact with aquaporins in affinity pull-down experiments on microsomal membrane vesicles. Furthermore, protoplast swelling assays of sirk1 mutants and SIRK1-GFP expressing lines confirmed a direct functional interaction of receptor kinase SIRK1 and aquaporins as substrates for phosphorylation. A lack of SIRK1 expression resulted in the failure of mutant protoplasts to control water channel activity upon changes in external sucrose concentrations. We propose that SIRK1 is involved in the regulation of sucrose-specific osmotic responses through direct interaction with and activation of an aquaporin via phosphorylation and that the duration of this response is controlled by phosphorylation-dependent receptor internalization. PMID:23820729

  18. Sucrose and raffinose family oligosaccharides (RFOs) in soybean seeds as influenced by genotype and growing location.

    PubMed

    Kumar, Vineet; Rani, Anita; Goyal, Lokesh; Dixit, Amit Kumar; Manjaya, J G; Dev, Jai; Swamy, M

    2010-04-28

    Sucrose content in soybean seeds is desired to be high because as a sweetness-imparting component, it helps in wider acceptance of soy-derived food products. Conversely, galactosyl derivatives of sucrose, that is, raffinose and stachyose, which are flatulence-inducing components, need to be in low concentration in soybean seeds not only for augmenting utilization of the crop in food uses but also for delivering soy meal with improved metabolizable energy for monogastric animals. In the present study, analysis of 148 soybean genotypes for sucrose and total raffinose family oligosaccharides (RFOs) contents revealed a higher variation (4.80-fold) for sucrose than for RFOs content (2.63-fold). High-performance liquid chromatography analyses revealed ranges of 0.64-2.53 and 2.09-7.1 mmol/100 g for raffinose and stachyose contents, respectively. As information concerning the environmental effects on the sucrose and RFOs content in soybean seeds is not available, we also investigated a set of seven genotypes raised at widely different geographical locations for these quality traits. Sucrose content was found to be significantly higher at cooler location (Palampur); however, differences observed for raffinose and stachyose contents across the growing locations were genotype-dependent. The results suggest that soybean genotypes grown at cooler locations may be better suited for processing soy food products with improved taste and flavor. PMID:20353171

  19. Sucrose-diet feeding induces gene expression of heat shock protein in rat brain under stress.

    PubMed

    Kageyama, H; Suzuki, E; Kashiwa, T; Kanazawa, M; Osaka, T; Kimura, S; Namba, Y; Inoue, S

    2000-08-01

    Stress-induced hyperphagia is enhanced in the presence of sweets, particularly sucrose, which may act to attenuate stress. Recently, it was also reported that heat shock protein (HSP) may be involved in the defense against stress. To explore whether sucrose alters gene expression of HSP under stress, we determined the HSP mRNA levels in the hypothalamus, cerebellum, and cerebral cortex after restraint stress in sucrose-diet-fed rats. Competitive RT-PCR revealed that gene expressions of HSP27 in the cerebral cortex and cerebellum and of HSP70 in the cerebral cortex, hypothalamus, and cerebellum were induced by restraint stress under a sucrose-diet-fed condition. However, restraint stress by itself or sucrose diet alone did not induce expression of HSP27 or HSP70 mRNA in any of the three anatomical parts. It is suggested that sucrose facilitates the gene expression of HSP27 and HSP70 in brain after restraint stress, which may attenuate stress. PMID:10913343

  20. Transport of Stachyose and Sucrose by Vacuoles of Japanese Artichoke (Stachys sieboldii) Tubers 1

    PubMed Central

    Keller, Felix

    1992-01-01

    Vacuoles are the stores for large amounts of stachyose [?gal (1,6) ?gal (1,6) ?glc (1,2) ?fru] in tubers of Japanese artichoke (Stachys sieboldii). The uptake of stachyose by these vacuoles was examined and compared with that of sucrose. The uptake mechanisms of both sugars were quite similar. The kinetics showed a single saturable response to increasing external concentrations of 14C-sugars with similar apparent Km values of about 50 and 30 millimolar for stachyose and sucrose, respectively. The uptake rates, however, were always higher for stachyose than for sucrose. Stachyose and sucrose uptake was inhibited by fructose and raffinose, and, reciprocally, by sucrose and stachyose, but not by glucose or galactose. The main structural feature common to all sugars recognized by the uptake systems seems to be a terminal fructosyl residue. The uptake of both sugars was stimulated by Mg-ATP and inorganic pyrophosphate, suggesting a proton-sugar antiport system. The possibility that stachyose and sucrose might be transported by the same carrier is discussed. PMID:16668659

  1. Is there a specific role for sucrose in sports and exercise performance?

    PubMed

    Wallis, Gareth A; Wittekind, Anna

    2013-12-01

    The consumption of carbohydrate before, during, and after exercise is a central feature of the athlete's diet, particularly those competing in endurance sports. Sucrose is a carbohydrate present within the diets of athletes. Whether sucrose, by virtue of its component monosaccharides glucose and fructose, exerts a meaningful advantage for athletes over other carbohydrate types or blends is unclear. This narrative reviews the literature on the influence of sucrose, relative to other carbohydrate types, on exercise performance or the metabolic factors that may underpin exercise performance. Inference from the research to date suggests that sucrose appears to be as effective as other highly metabolizable carbohydrates (e.g., glucose, glucose polymers) in providing an exogenous fuel source during endurance exercise, stimulating the synthesis of liver and muscle glycogen during exercise recovery and improving endurance exercise performance. Nonetheless, gaps exist in our understanding of the metabolic and performance consequences of sucrose ingestion before, during, and after exercise relative to other carbohydrate types or blends, particularly when more aggressive carbohydrate intake strategies are adopted. While further research is recommended and discussed in this review, based on the currently available scientific literature it would seem that sucrose should continue to be regarded as one of a variety of options available to help athletes achieve their specific carbohydrate-intake goals. PMID:23630082

  2. Producing aglycons of ginsenosides in bakers' yeast

    PubMed Central

    Dai, Zhubo; Wang, Beibei; Liu, Yi; Shi, Mingyu; Wang, Dong; Zhang, Xianan; Liu, Tao; Huang, Luqi; Zhang, Xueli

    2014-01-01

    Ginsenosides are the primary bioactive components of ginseng, which is a popular medicinal plant that exhibits diverse pharmacological activities. Protopanaxadiol, protopanaxatriol and oleanolic acid are three basic aglycons of ginsenosides. Producing aglycons of ginsenosides in Saccharomyces cerevisiae was realized in this work and provides an alternative route compared to traditional extraction methods. Synthetic pathways of these three aglycons were constructed in S. cerevisiae by introducing ?-amyrin synthase, oleanolic acid synthase, dammarenediol-II synthase, protopanaxadiol synthase, protopanaxatriol synthase and NADPH-cytochrome P450 reductase from different plants. In addition, a truncated 3-hydroxy-3-methylglutaryl-CoA reductase, squalene synthase and 2,3-oxidosqualene synthase genes were overexpressed to increase the precursor supply for improving aglycon production. Strain GY-1 was obtained, which produced 17.2?mg/L protopanaxadiol, 15.9?mg/L protopanaxatriol and 21.4?mg/L oleanolic acid. The yeast strains engineered in this work can serve as the basis for creating an alternative way for producing ginsenosides in place of extractions from plant sources. PMID:24424342

  3. A Sucrose-derived Scaffold for Multimerization of Bioactive Peptides

    PubMed Central

    Rao, Venkataramanarao; Alleti, Ramesh; Xu, Liping; Tafreshi, Narges K.; Morse, David L.; Gillies, Robert J.; Mash, Eugene A.

    2011-01-01

    A spherical molecular scaffold bearing eight terminal alkyne groups was synthesized in one step from sucrose. One or more copies of a tetrapeptide azide, either N3(CH2)5(C=O)-His-dPhe-Arg-Trp-NH2 (MSH4) or N3(CH2)5(C=O)-Trp-Met-Asp-Phe-NH2 (CCK4), were attached to the scaffold via the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction. Competitive binding assays using Eu-labeled probes based on the superpotent ligands Ser-Tyr-Ser-Nle-Glu-His-dPhe-Arg-Trp-Gly-Lys-Pro-Val-NH2 (NDP-?-MSH) and Asp-Tyr-Met-Gly-Trp-Met-Asp-Phe-NH2 (CCK8) were used to study the interactions of monovalent and multivalent MSH4 and CCK4 constructs with Hek293 cells engineered to overexpress MC4R and CCK2R. All of the monovalent and multivalent MSH4 constructs exhibited binding comparable to that of the parental ligand, suggesting that either the ligand spacing was inappropriate for multivalent binding, or MSH4 is too weak a binder for a second “anchoring” binding event to occur before the monovalently-bound construct is released from the cell surface. In contrast with this behavior, monovalent CCK4 constructs were significantly less potent than the parental ligand, while multivalent CCK4 constructs were as or more potent than the parental ligand. These results are suggestive of multivalent binding, which may be due to increased residence times for monovalently bound CCK4 constructs on the cell surface relative to MSH4 constructs, the greater residence time being necessary for the establishment of multivalent binding. PMID:21940174

  4. Concentration-Dependent Effects of Rhodiola Rosea on Long-Term Survival and Stress Resistance of Yeast Saccharomyces Cerevisiae: The Involvement of YAP 1 and MSN2/4 Regulatory Proteins

    PubMed Central

    Bayliak, Maria M.; Burdyliuk, Nadia I.; Izers’ka, Lilia I.; Lushchak, Volodymyr I.

    2014-01-01

    Concentration-dependent effects of aqueous extract from R. rosea root on long-term survival and stress resistance of budding yeast Saccharomyces cerevisiae were studied. At low concentrations, R. rosea aqueous extract extended yeast chronological lifespan, enhanced oxidative stress resistance of stationary-phase cells and resistance to number stressors in exponentially growing cultures. At high concentrations, R. rosea extract sensitized yeast cells to stresses and shortened yeast lifespan. These biphasic concentration-responses describe a common hormetic phenomenon characterized by a low-dose stimulation and a high-dose inhibition. Yeast pretreatment with low doses of R. rosea extract enhanced yeast survival and prevented protein oxidation under H2O2-induced oxidative stress. Positive effect of R. rosea extract on yeast survival under heat shock exposure was not accompanied with changes in antioxidant enzyme activities and levels of oxidized proteins. The deficiency in transcriptional regulators, Msn2/Msn4 and Yap1, abolished the positive effect of low doses of R. rosea extract on yeast viability under stress challenges. Potential involvement of Msn2/Msn4 and Yap1 regulatory proteins in realization of R. rosea beneficial effects is discussed. PMID:24659935

  5. Yeast Cultures in Ruminant Nutrition

    Microsoft Academic Search

    S. A. DENEV; Tz. PEEVA; P. RADULOVA; N. STANCHEVA; G. STAYKOVA; G. BEEV; P. TODOROVA; S. TCHOBANOVA

    2007-01-01

    Abstract DENEV,, S. A., Tz. PEEVA, P. RADULOVA, P. STANCHEVA, G. STAYKOVA, G. BEEV, P. TODOROVA and S. TCHOBANOVA, 2007. Yeast cultures in ruminant nutrition. Bulg. J. Agric. Sci.13: 357-374 Interest in the use of fungal direct-fed microbials in ruminant nutrition is considerable.The

  6. Malassezia Baillon, emerging clinical yeasts

    Microsoft Academic Search

    Roma Batra; Teun Boekhout; Eveline Guého; F. Javier Cabañes; Thomas L. Dawson; Aditya K. Gupta

    2005-01-01

    The human and animal pathogenic yeast genus Malassezia has received considerable attention in recent years from dermatologists, other clinicians, veterinarians and mycologists. Some points highlighted in this review include recent advances in the technological developments related to detection, identification, and classification of Malassezia species. The clinical association of Malassezia species with a number of mammalian dermatological diseases including dandruff, seborrhoeic

  7. Endoplasmic reticulum involvement in yeast cell death

    PubMed Central

    Austriaco, O. P., Nicanor

    2012-01-01

    Yeast cells undergo programed cell death (PCD) with characteristic markers associated with apoptosis in mammalian cells including chromatin breakage, nuclear fragmentation, reactive oxygen species generation, and metacaspase activation. Though significant research has focused on mitochondrial involvement in this phenomenon, more recent work with both Saccharomyces cerevisiae and Schizosaccharomyces pombe has also implicated the endoplasmic reticulum (ER) in yeast PCD. This minireview provides an overview of ER stress-associated cell death (ER-SAD) in yeast. It begins with a description of ER structure and function in yeast before moving to a discussion of ER-SAD in both mammalian and yeast cells. Three examples of yeast cell death associated with the ER will be highlighted here including inositol starvation, lipid toxicity, and the inhibition of N-glycosylation. It closes by suggesting ways to further examine the involvement of the ER in yeast cell death. PMID:22876361

  8. Development of an integrated electrochemical biosensor for sucrose and its implementation in a continuous flow system for the simultaneous monitoring of sucrose, fructose and glucose.

    PubMed

    Vargas, E; Gamella, M; Campuzano, S; Guzmán-Vázquez de Prada, A; Ruiz, M A; Reviejo, A J; Pingarrón, J M

    2013-02-15

    An integrated amperometric sucrose biosensor involving a 3-mercaptopropionic acid (MPA) self-assembled monolayer (SAM)-modified gold disk electrode (AuE) and coimmobilization of the enzymes invertase (INV) and fructose dehydrogenase (FDH) as well as the redox mediator tetrathiafulvalene (TTF) by means of a dialysis membrane is reported. Amperometry in stirred solutions at a detection potential of +0.10 V provided a linear calibration plot for sucrose over the 1.2 × 10(-6)-3.0 × 10(-3) mol L(-1) concentration range, with a limit of detection of 3.6 × 10(-7) mol L(-1). The practical usefulness of the biosensor was demonstrated by determining sucrose in condensed milk and in an infant food reference material with good results. Additionally, the biosensor was implemented together with commercial fructose and glucose amperometric biosensors in a continuous flow system to perform the multiplexed quantification of sucrose, fructose and glucose in a single experiment. The operational characteristics of the biosensors in this novel flow system were evaluated and their applicability was demonstrated through the simultaneous determination of the three sugars in the above-mentioned reference material. PMID:23597994

  9. Embryo Staining Protocol. 1. Keep the flies for egg laying on agar sucrose plates (1.5% agar, 1.5% sucrose)

    E-print Network

    Embryo Staining Protocol. 1. Keep the flies for egg laying on agar sucrose plates (1.5% agar, 1. With a brush and distilled water transfer the embryos into an egg basket. (egg baskets can be made by cutting the embryos in distilled water. 5. Soak in 50% bleach for 2 minutes. This removes the chorion. Look under

  10. Sucrose Accumulation in the Sugarcane Stem 1s Regulated by the Difference between the Activities of Soluble Acid Invertase and Sucrose Phosphate Synthase

    Microsoft Academic Search

    Yun J. Zhu; Ewald Komor; Paul H. Moore

    To asses the relative importance of morphological and biochem- ical factors in the regulation of sucrose (Suc) accumulation in the sugarcane (Saccharum spp. hybrids) stem, we investigated morpho- logical and biochemical correlates of Suc accumulation among parents and progeny of a family segregating for differences. In contrast to the parents, no relationship was observed between morphology and the level of

  11. Expression Patterns, Activities and Carbohydrate-Metabolizing Regulation of Sucrose Phosphate Synthase, Sucrose Synthase and Neutral Invertase in Pineapple Fruit during Development and Ripening

    PubMed Central

    Zhang, Xiu-Mei; Wang, Wei; Du, Li-Qing; Xie, Jiang-Hui; Yao, Yan-Li; Sun, Guang-Ming

    2012-01-01

    Differences in carbohydrate contents and metabolizing-enzyme activities were monitored in apical, medial, basal and core sections of pineapple (Ananas comosus cv. Comte de paris) during fruit development and ripening. Fructose and glucose of various sections in nearly equal amounts were the predominant sugars in the fruitlets, and had obvious differences until the fruit matured. The large rise of sucrose/hexose was accompanied by dramatic changes in sucrose phosphate synthase (SPS) and sucrose synthase (SuSy) activities. By contrast, neutral invertase (NI) activity may provide a mechanism to increase fruit sink strength by increasing hexose concentrations. Furthermore, two cDNAs of Ac-sps (accession no. GQ996582) and Ac-ni (accession no. GQ996581) were first isolated from pineapple fruits utilizing conserved amino-acid sequences. Homology alignment reveals that the amino acid sequences contain some conserved function domains. Transcription expression analysis of Ac-sps, Ac-susy and Ac-ni also indicated distinct patterns related to sugar accumulation and composition of pineapple fruits. It suggests that differential expressions of multiple gene families are necessary for sugar metabolism in various parts and developmental stages of pineapple fruit. A cycle of sucrose breakdown in the cytosol of sink tissues could be mediated through both Ac-SuSy and Ac-NI, and Ac-NI could be involved in regulating crucial steps by generating sugar signals to the cells in a temporally and spatially restricted fashion. PMID:22949808

  12. Clinical inquiry: is red-yeast rice a safe and effective alternative to statins?

    PubMed

    Chen, Hsiang-Hwa Shawn; Neher, Jon; Safranek, Sarah

    2015-02-01

    In patients with known coronary artery disease and dyslipidemia (secondary prevention), therapy with red-yeast rice extract containing naturally-occurring lovastatin is associated with a 30% reduction in coronary heart disease (CHD) mortality and a 60% reduction in myocardial infarction (MI), similar to the effect of statin medications. PMID:25671533

  13. Effects of Solid-State Yeast Treatment on the Antioxidant Properties and Protein and Fiber

    E-print Network

    Liu, Jian-Guo

    Effects of Solid-State Yeast Treatment on the Antioxidant Properties and Protein and Fiber, including extractable antioxidant properties, protein contents, and soluble and insoluble fiber compositions treatments were able to significantly increase releasable antioxidant properties ranging from 28 to 65, from

  14. Overexpression of a small medicinal peptide from ginseng in the yeast Pichia pastoris

    Microsoft Academic Search

    Yajun Yan; Jingchun Chen; Jun Li

    2003-01-01

    A medicinal peptide, Gsp, which was initially extracted from the traditional medicinal herb ginseng, has potential use as a drug against diabetes. Gsp is a low molecular weight protein that we have secreted in a recombinant form from the yeast Pichia pastoris. A DNA fragment encoding four copies of the Gsp protein each separated by a basic amino acid was

  15. Loss of the two major leaf isoforms of sucrose-phosphate synthase in Arabidopsis thaliana limits sucrose synthesis and nocturnal starch degradation but does not alter carbon partitioning during photosynthesis.

    PubMed

    Volkert, Kathrin; Debast, Stefan; Voll, Lars M; Voll, Hildegard; Schießl, Ingrid; Hofmann, Jörg; Schneider, Sabine; Börnke, Frederik

    2014-10-01

    Sucrose (Suc)-phosphate synthase (SPS) catalyses one of the rate-limiting steps in the synthesis of Suc in plants. The Arabidopsis genome contains four annotated SPS genes which can be grouped into three different families (SPSA1, SPSA2, SPSB, and SPSC). However, the functional significance of this multiplicity of SPS genes is as yet only poorly understood. All four SPS isoforms show enzymatic activity when expressed in yeast although there is variation in sensitivity towards allosteric effectors. Promoter-reporter gene analyses and quantitative real-time reverse transcription-PCR studies indicate that no two SPS genes have the same expression pattern and that AtSPSA1 and AtSPSC represent the major isoforms expressed in leaves. An spsa1 knock-out mutant showed a 44% decrease in leaf SPS activity and a slight increase in leaf starch content at the end of the light period as well as at the end of the dark period. The spsc null mutant displayed reduced Suc contents towards the end of the photoperiod and a concomitant 25% reduction in SPS activity. In contrast, an spsa1/spsc double mutant was strongly impaired in growth and accumulated high levels of starch. This increase in starch was probably not due to an increased partitioning of carbon into starch, but was rather caused by an impaired starch mobilization during the night. Suc export from excised petioles harvested from spsa1/spsc double mutant plants was significantly reduced under illumination as well as during the dark period. It is concluded that loss of the two major SPS isoforms in leaves limits Suc synthesis without grossly changing carbon partitioning in favour of starch during the light period but limits starch degradation during the dark period. PMID:24994761

  16. Object extraction Object extraction

    E-print Network

    Giger, Christine

    (is a grass-roof a vegetation area?) · object ontologies are hierarchical (tree / forrest / vegetation · buildings · vegetation · roads #12;Interactive object extraction #12;Interactive object extraction angles in man-made structures · measurement accuracy of human operator is lower than that of automatic

  17. A zinc finger protein from Candida albicans is involved in sucrose utilization.

    PubMed

    Kelly, R; Kwon-Chung, K J

    1992-01-01

    A sucrose-inducible alpha-glucosidase activity that hydrolyzes sucrose in Candida albicans has been demonstrated previously. The enzyme is assayable in whole cells and was inhibited by both sucrose and maltose. A C. albicans gene (CASUC1) that affects sucrose utilization and alpha-glucosidase activity was cloned by expression in a Saccharomyces cerevisiae suc2 mutant (2102) devoid of invertase genes. CASUC1 enabled the S. cerevisiae mutant to utilize both sucrose and maltose. DNA sequence analysis revealed that CASUC1 encodes a putative zinc finger-containing protein with 28% identity to a maltose-regulatory gene (MAL63) of S. cerevisiae. The gene products of CASUC1 and MAL63 are approximately the same size (501 and 470 amino acids, respectively), and each contains a single zinc finger located at the N terminus. The zinc fingers of CASUC1 and MAL63 comprise six conserved cysteines (C6 zinc finger) and are of the general form Cys-Xaa2-Cys-Xaa6-Cys-Xaavariable-Cys-Xaa2-Cys-+ ++Xaa6-Cys (where Xaan indicates a stretch of the indicated number of any amino acids). Both contain five amino acids in the variable region. CASUC1 also complemented the maltose utilization defect of an S. cerevisiae mutant (TCY-137) containing a defined mutation in a maltose-regulatory gene. The sucrose utilization defect of type II Candida stellatoidea, a sucrase-negative mutant of C. albicans, was corrected by CASUC1. Determinations of alpha-glucosidase activity in whole cells revealed that activity was restored in transformants cultivated on either sucrose or maltose. To our knowledge, this is the first zinc finger-encoding gene, as well as the first putative regulatory gene, to be identified in C. albicans. PMID:1729210

  18. Hexosamine biosynthetic pathway activity in leptin resistant sucrose-drinking rats.

    PubMed

    Harris, Ruth B S; Apolzan, John W

    2015-01-01

    Rats offered 30% sucrose solution in addition to chow and water become leptin resistant therefore we investigated the effect of sucrose solution consumption on leptin signaling. In Experiment 1 rats were resistant to 3rd ventricle injections of1.5 ?g leptin after 36 days of sucrose and western blot indicated that resistance was associated with increased basal levels of signal transducer and activator of transcription 3 phosphorylation (pSTAT3). In Experiment 2 rats were resistant to a peripheral injection of 2mg leptin/kg after 26 days of sucrose. Immunohistochemistry indicated that increased basal pSTAT3 was limited to the medial and lateral arcuate nucleus of the hypothalamus. Increased availability of glucose and fructose can stimulate the hexosamine biosynthetic pathway (HBP) which O-GlcNAc-modifies proteins. This has the potential to change protein bioactivity. We tested whether this pathway could account for the leptin resistance. There was no increase in the expression of HBP enzymes in tissues from sucrose rats in Experiment 1, however, direct activation of the HBP with a 3h intravenous infusion of 30 ?mol/kg/min glucosamine significantly increased hypothalamic pSTAT3. Although sucrose consumption and activation of the HBP both increase hypothalamic pSTAT3 experiments described here did not provide evidence of a direct link between sucrose consumption, HBP activity and leptin resistance. Unexpectedly, we found that the HBP enzyme glutamine fructose-6-phosphate amidotransferase (GFAT) in liver and O-GlcNAcase in hypothalamus were increased 30min after leptin injection in leptin responsive animals, implying a complex interaction between activity of the HBP and leptin responsiveness. PMID:25446204

  19. Comparison and validation of two analytical methods for measurement of urinary sucrose and fructose excretion

    PubMed Central

    Song, Xiaoling; Navarro, Sandi L.; Diep, Pho; Thomas, Wendy K.; Razmpoosh, Elena C.; Schwarz, Yvonne; Wang, Ching-Yun; Kratz, Mario; Neuhouser, Marian L.; Lampe, Johanna W.

    2013-01-01

    Urinary sugars excretion has been proposed as a potential biomarker for intake of sugars. In this study we compared two analytical methods [gas chromatography (GC) and enzymatic reactions – UV absorption] for quantifying urinary fructose and sucrose using 24-hour urine samples from a randomized cross-over controlled feeding study. All samples were successfully quantified by the GC method; however 21% and 1.9% of samples were below the detection limit of the enzymatic method for sucrose and fructose, respectively. While the correlation between the two methods was good for fructose (Pearson correlation 0.71), the correlation was weak for sucrose (Pearson correlation 0.27). We favor the GC method due to its better sensitivity, simplicity, and the ability to quantify fructose and sucrose directly in the same run. Of the 106 samples from 53 participants with complete urine collection after two study diets, 24-hour urinary fructose excretion was significantly associated with fructose intake. The sum of 24-hour urinary fructose and sucrose was significantly associated with total sugars consumption. However, variation in intakes of sugars explained only a modest amount of variation in urinary sugars excretion. In the unadjusted models, fructose intake explained 24.3% of urinary fructose excretion; and intake of total sugars 16.3% of the sum of urinary fructose and sucrose. The adjusted models explained 44.3% of urinary fructose excretion and 41.7% of the sum of urinary fructose and sucrose. Therefore, we caution using these biomarkers to predict sugars consumption before other factors that determine urinary sugars excretion are understood. PMID:24034568

  20. Differences in bingeing behavior and cocaine reward following intermittent access to sucrose, glucose or fructose solutions.

    PubMed

    Rorabaugh, J M; Stratford, J M; Zahniser, N R

    2015-08-20

    Daily intermittent access to sugar solutions results in intense bouts of sugar intake (i.e. bingeing) in rats. Bingeing on sucrose, a disaccharide of glucose and fructose, has been associated with a "primed" mesolimbic dopamine (DA) pathway. Recent studies suggest glucose and fructose engage brain reward and energy-sensing mechanisms in opposing ways and may drive sucrose intake through unique neuronal circuits. Here, we examined in male Sprague-Dawley rats whether or not (1) intermittent access to isocaloric solutions of sucrose, glucose or fructose results in distinctive sugar-bingeing profiles and (2) previous sugar bingeing alters cocaine locomotor activation and/or reward, as determined by conditioned place preference (CPP). To encourage bingeing, rats were given 24-h access to water and 12-h-intermittent access to chow plus an intermittent bottle that contained water (control) or 8% solutions of sucrose, glucose or fructose for 9days, followed by ad libitum chow diet and a 10-day cocaine (15mg/kg; i.p.) CPP paradigm. By day 4 of the sugar-bingeing diet, sugar bingeing in the fructose group surpassed the glucose group, with the sucrose group being intermediate. All three sugar groups had similar chow and water intake throughout the diet. In contrast, controls exhibited chow bingeing by day 5 without altering water intake. Similar magnitudes of cocaine CPP were observed in rats with a history of sucrose, fructose or chow (control) bingeing. Notably, the glucose-bingeing rats did not demonstrate a significant cocaine CPP despite showing similar cocaine-induced locomotor activity as the other diet groups. Overall, these results show that fructose and glucose, the monosaccharide components of sucrose, produce divergent degrees of bingeing and cocaine reward. PMID:26079112

  1. Production of flavour-active methionol from methionine metabolism by yeasts in coconut cream.

    PubMed

    Seow, Yi-Xin; Ong, Peter K C; Liu, Shao-Quan

    2010-10-15

    Yeasts Candida kefyr NCYC143, Candida utilis CUM, Kluyveromyces lactis KL71, Saccharomyces bayanus SB1, Saccharomyces cerevisiae EC1118, Saccharomyces chevalieri CCICC1028, Candida famata (previously Torulopsis candida) CCICC1041 and Williopsis saturnus var. saturnus CBS254 were screened for their ability to produce flavour-active methionol (3-methylthio-1-propanol) in coconut cream supplemented with l-methionine. The yeasts varied with their ability to produce methionol from methionine with Saccharomyces cerevisiae EC1118 producing the most, followed by Kluyveromyces lactis KL71. Little methionol was produced by the other yeasts. Methionol production by Kluyveromyces lactis KL71 was subjected to further studies under different conditions of initial pH (4.0-6.3), temperature (20-33 °C), l-methionine concentration (0.05-0.25%) and yeast extract concentration (0-0.50%); optimal conditions were established at pH 5.0, 33.0 °C, 0.15% l-methionine and 0.05% yeast extract. CharmAnalysis™ using SPME-GC-MS was conducted on the coconut cream ferment; methional (3-methylthio-1-propanal), methionol and 2-phenylethyl acetate were found to be the most potent aroma-active compounds. The product of coconut cream fermentation by Kluyveromyces lactis KL71 may be considered as a novel, plant-based, natural and complex flavoring bioingredient in food applications. PMID:20805008

  2. Acylated sucroses and acylated quinic acids analogs from the flower buds of Prunus mume and their inhibitory effect on melanogenesis.

    PubMed

    Nakamura, Seikou; Fujimoto, Katsuyoshi; Matsumoto, Takahiro; Nakashima, Souichi; Ohta, Tomoe; Ogawa, Keiko; Matsuda, Hisashi; Yoshikawa, Masayuki

    2013-08-01

    The methanolic extract from the flower buds of Prunus mume, cultivated in Zhejiang Province, China, showed an inhibitory effect on melanogenesis in theophylline-stimulated B16 melanoma 4A5 cells. From the methanolic extract, five acylated sucroses, mumeoses A-E, and three acylated quinic acid analogs, 5-O-(E)-p-coumaroylquinic acid ethyl ester, and mumeic acid-A and its methyl ester, were isolated together with 13 known compounds. The chemical structures of the compounds were elucidated on the basis of chemical and physicochemical evidence. Inhibitory effects of the isolated compounds on melanogenesis in theophylline-stimulated B16 melanoma 4A5 cells were also investigated. Acylated quinic acid analogs substantially inhibited melanogenesis. In particular, 5-O-(E)-feruloylquinic acid methyl ester exhibited a potent inhibitory effect [inhibition (%): 21.5±1.0 (P<0.01) at 0.1 ?M]. Moreover, its biological effect was much stronger than that of the reference compound, arbutin [inhibition (%): 10.6±0.6 (P<0.01) at 10 ?M]. Interestingly, the obtained acylated quinic acid analogs displaying melanogenesis inhibitory activity showed no cytotoxicity [cell viability >97% at 10 ?M]. It is concluded that acylated quinic acid analogs are promising therapeutic agents for the treatment of skin disorders. PMID:23693120

  3. Mycotoxins - prevention and decontamination by yeasts.

    PubMed

    Pfliegler, Walter P; Pusztahelyi, Tünde; Pócsi, István

    2015-07-01

    The application of yeasts has great potential in reducing the economic damage caused by toxigenic fungi in the agriculture. Some yeasts may act as biocontrol agents inhibiting the growth of filamentous fungi. These species may also gain importance in the preservation of agricultural products and in the reduction of their mycotoxin contamination, yet the extent of mycotoxin production in the presence of biocontrol agents is relatively less understood. The application of yeasts in various technological processes may have a direct inhibitory effect on the toxin production of certain molds, which is independent of their growth suppressing effect. Furthermore, several yeast species are capable of accumulating mycotoxins from agricultural products, thereby effectively decontaminating them. Probiotic yeasts or products containing yeast cell wall are also applied to counteract mycotoxicosis in livestock. Several yeast strains are also able to degrade toxins to less-toxic or even non-toxic substances. This intensively researched field would greatly benefit from a deeper knowledge on the genetic and molecular basis of toxin degradation. Moreover, yeasts and their biotechnologically important enzymes may exhibit sensitivity to certain mycotoxins, thereby mounting a considerable problem for the biotechnological industry. It is noted that yeasts are generally regarded as safe; however, there are reports of toxin degrading species that may cause human fungal infections. The aspects of yeast-mycotoxin relations with a brief consideration of strain improvement strategies and genetic modification for improved detoxifying properties and/or mycotoxin resistance are reviewed here. PMID:25682759

  4. Medicinal flowers. XXXVIII. structures of acylated sucroses and inhibitory effects of constituents on aldose reducatase from the flower buds of Prunus mume.

    PubMed

    Fujimoto, Katsuyoshi; Nakamura, Seikou; Matsumoto, Takahiro; Ohta, Tomoe; Ogawa, Keiko; Tamura, Haruka; Matsuda, Hisashi; Yoshikawa, Masayuki

    2013-01-01

    The methanolic extract from the flower buds of Prunus mume, cultivated in Zhejiang province, China, showed an inhibitory effect on aldose reductase. From the methanolic extract, five new acylated sucroses, mumeoses F-J, were isolated together with 29 known compounds. The chemical structures of the new compounds were elucidated on the basis of chemical and physicochemical evidence. The inhibitory effects of the isolated compounds on aldose reductase were also investigated. Acylated quinic acid analogs, which are one of the major compounds of the flower buds of P. mume, were shown to substantially inhibit aldose reductase. In particular, mumeic acid-A was found to exhibit a potent inhibitory effect [IC50=0.4?µm]. PMID:23546004

  5. Protective effect of sucrose on the membrane properties of Lactobacillus casei Zhang subjected to freeze-drying.

    PubMed

    Li, Haiping; Lu, Meijun; Guo, Hongfang; Li, Wei; Zhang, Heping

    2010-04-01

    The purpose of this research was to investigate the influence of sucrose at 2.0, 4.0, and 8.0% as a protectant during freeze-drying on the viability and membrane properties of Lactobacillus casei Zhang. Membrane properties were determined using zeta potential, hydrophobicity, fluidity, and integrity before and after freeze-drying. Exposing L. casei Zhang to sucrose protected it from drastic changes in cell surface electrophoretic mobility and hydrophobicity in contrast with the untreated condition, and the effect was dose related. Sucrose caused an increase in membrane fluidity compared with the control sample. Moreover, 2.0% sucrose decreased the general polarization values less than 4.0 or 8.0% sucrose, while 4.0% sucrose and 8.0% sucrose had no significant difference in decreasing general polarization values (P < 0.05). L. casei Zhang freeze-dried in the presence of 2.0% sucrose retained up to 23.7% membrane integrity, whereas cells freeze-dried with 4.0 and 8.0% sucrose had 32.4 and 37.6% membrane integrity compared with that of L. casei Zhang before freeze-drying. Correspondingly, the number of survivors of L. casei Zhang, determined by the plate count method, decreased from 8.02 to 0.63 log CFU/ml after freeze-drying in the absence of sucrose. However, in the presence of 2.0, 4.0, and 8.0% sucrose, the numbers of survivors were 2.01, 2.87, and 3.20 log CFU/ml after freeze-drying, respectively. The present work suggested that sucrose was an effective membrane protectant at 2.0, 4.0, or 8.0% on the surface zeta potential, hydrophobicity, fluidity, and integrity of L. casei Zhang. PMID:20377961

  6. Yeast Metabolism Lab Purpose: To determine the effects of different

    E-print Network

    Rose, Michael R.

    1 Yeast Metabolism Lab Purpose: To determine the effects of different carbohydrates on the metabolism of live yeast. Background: Some organisms are capable of photosynthesis- using energy captured treatment (yeast+water, yeast+glucose, or yeast+sweetener) will produce the most carbon dioxide (CO2) from

  7. Morphology of a human-derived YAC in yeast meiosis

    Microsoft Academic Search

    Josef Loidl; Harry Scherthan; Johan T. Den Dunnen; Franz Klein

    1995-01-01

    In meiosis of human males DNA is packaged along pachytene chromosomes about 20 time more compactly than in meiosis of yeast. Nevertheless, a human-derived yeast artificial chromosome (YAC) shows the same degree of compaction of DNA as endogenous chromosomes in meiotic prophase nuclei of yeast. This suggests that in yeast meiosis, human and yeast DNA adopt a similar organization of

  8. Morphology of a human-derived YAC in yeast meiosis

    Microsoft Academic Search

    Josef Loidl; Harry Scherthan; Johan T. Den Dunnen; Franz Klein

    1995-01-01

    In meiosis of human males DNA is packaged along pachytene chromosomes about 20 times more compactly than in meiosis of yeast. Nevertheless, a human-derived yeast artificial chromosome (YAC) shows the same degree of compaction of DNA as endogenous chromosomes in meiotic prophase nuclei of yeast. This suggests that in yeast meiosis, human and yeast DNA adopt a similar organization of

  9. Carbohydrate profiling in seeds and seedlings of transgenic triticale modified in the expression of sucrose:sucrose-1-fructosyltransferase (1-SST) and sucrose:fructan-6-fructosyltransferase (6-SFT).

    PubMed

    Diedhiou, Calliste; Gaudet, Denis; Liang, Yehong; Sun, Jinyue; Lu, Zhen-Xing; Eudes, François; Laroche, André

    2012-10-01

    Constructs with sucrose-sucrose 1-fructosyltransferase (1-SST) from rye and or sucrose-fructan 6-fructosyltransferase (6-SFT) from wheat were placed under the control of wheat aleurone-specific promoter and expressed in triticale using biolistic and microspore transformation. Transgenic lines expressing one or both the 1-SST and the 6-SFT accumulated 50% less starch and 10-20 times more fructan, particularly 6-kestose, in the dry seed compared to the untransformed wild-type (WT) triticale; other fructans ranged in size from DP 4 to DP 15. During germination from 1 to 4 days after imbibition (dai), fructans were rapidly metabolized and only in transgenic lines expressing both 1-SST and 6-SFT were fructan contents significantly higher than in the untransformed controls after 4 days. In situ hybridization confirmed expression of 6-SFT in the aleurone layer in imbibed seeds of transformed plants. When transgenic lines were subjected to a cold stress of 4°C for 2 days, synthesis of fructan increased compared to untransformed controls during low-temperature germination. The increase of fructan in dry seed and germinating seedling was generally associated with transcript expression levels in transformed plants but total gene expression was not necessarily correlated with the time course accumulation of fructan during germination. This is the first report of transgenic modification of cereals to achieve production of fructans in cereal seeds and during seed germination. PMID:22698728

  10. The proteolytic system of the fission yeast Schizosaccharomyces pombe.

    PubMed

    Suárez-Rendueles, P; Villa, L; Arbesú, M J; Escudero, B

    1991-06-15

    Proteinase and peptidase activities of the fission yeast Schizosaccharomyces pombe were investigated. Several intracellular proteolytic enzymes were found: two endoproteinases, one carboxypeptidase, one aminopeptidase and one dipeptidyl-aminopeptidase. In addition, proteinase inhibitors were detected. In fresh crude extracts an activation procedure is needed to measure maximal activities of endoproteinases and carboxypeptidase, whose level is markedly dependent on growth medium composition and on growth phase, while aminopeptidase and dipeptidyl-aminopeptidase activities are very little, if at all, regulated by the carbon source. PMID:1884996

  11. Purification and characterization of an invertase from Candida utilis: comparison with natural and recombinant yeast invertases.

    PubMed

    Chávez, F P; Rodriguez, L; Díaz, J; Delgado, J M; Cremata, J A

    1997-02-28

    A periplasmic invertase from the yeast Candida utilis was purified to homogeneity from cells fully derepressed for invertase synthesis. The enzyme was purified by successive Sephacryl S-300, and affinity chromatography and shown to be a dimeric glycoprotein composed of two identical monomer subunits with an apparent molecular mass of 150 kDa. After EndoH treatment, the deglycosylated protein showed an apparent molecular weight of 60 kDa. The apparent K(m) values for sucrose and raffinose were 11 and 150 mM, respectively, similar to those reported in Saccharomyces cerevisiae. The range of optimum temperature was 60-75 degrees C. The optimum pH was 5.5 and the enzyme was stable over pH range 3-6. PMID:9165761

  12. Expanding xylose metabolism in yeast for plant cell wall conversion to biofuels.

    PubMed

    Li, Xin; Yu, Vivian Yaci; Lin, Yuping; Chomvong, Kulika; Estrela, Raíssa; Park, Annsea; Liang, Julie M; Znameroski, Elizabeth A; Feehan, Joanna; Kim, Soo Rin; Jin, Yong-Su; Glass, N Louise; Cate, Jamie H D

    2015-01-01

    Sustainable biofuel production from renewable biomass will require the efficient and complete use of all abundant sugars in the plant cell wall. Using the cellulolytic fungus Neurospora crassa as a model, we identified a xylodextrin transport and consumption pathway required for its growth on hemicellulose. Reconstitution of this xylodextrin utilization pathway in Saccharomyces cerevisiae revealed that fungal xylose reductases act as xylodextrin reductases, producing xylosyl-xylitol oligomers as metabolic intermediates. These xylosyl-xylitol intermediates are generated by diverse fungi and bacteria, indicating that xylodextrin reduction is widespread in nature. Xylodextrins and xylosyl-xylitol oligomers are then hydrolyzed by two hydrolases to generate intracellular xylose and xylitol. Xylodextrin consumption using a xylodextrin transporter, xylodextrin reductases and tandem intracellular hydrolases in cofermentations with sucrose and glucose greatly expands the capacity of yeast to use plant cell wall-derived sugars and has the potential to increase the efficiency of both first-generation and next-generation biofuel production. PMID:25647728

  13. Kazachstania ichnusensis sp. nov., a diploid homothallic ascomycetous yeast from Sardinian lentisk rhizosphere.

    PubMed

    Cardinali, Gianluigi; Antonielli, Livio; Corte, Laura; Roscini, Luca; Bagnetti, Ambra; Pelliccia, Cristina; Puddu, Gianfranco

    2012-03-01

    During an investigation of yeast biota in the rhizosphere of lentisk in Sardinian semi-arid areas, a strain was isolated that could not be assigned to any known species. The sequence of the D1/D2 domain of the large subunit rDNA gene revealed that the strain belonged to the genus Kazachstania and was phylogenetically related to a clade including Kazachstania aerobia, Kazachstania servazzii, Kazachstania solicola and Kazachstania unispora. The novel isolate differed from members of this clade in its ability to assimilate D-glucono-1,5-lactone and its very weak fermentation of glucose and sucrose; its assimilation profile was unique within the genus Kazachstania. Monosporal colonies were able to sporulate, indicating that the species is homothallic. It is proposed that the isolate represents a novel species, Kazachstania ichnusensis sp. nov., with LCF 1675(T) (=CBS 11859(T)) as type strain. PMID:21498662

  14. Improving energetics of triacylglyceride extraction from wet oleaginous microbes.

    PubMed

    Willis, Robert M; McCurdy, Alex T; Ogborn, Mariah K; Wahlen, Bradley D; Quinn, Jason C; Pease, Leonard F; Seefeldt, Lance C

    2014-09-01

    Oleaginous microbes can upgrade carbon to lipids, which can be used as a feedstock to produce renewable replacements for petroleum-based compounds. Efficient extraction of lipids from oleaginous microbes typically involves dewatering and drying of the biomass. Problematically, drying often requires an amount of energy approaching that available from the cells. Here, we report an approach for the high efficiency extraction of triacylglycerides (TAG) from wet oleaginous microbes, bypassing the drying process. Solvent candidates for extraction of wet oleaginous biomass were identified using ASPEN's databases to determine an activity based selectivity coefficient. Optimal extraction conditions were determined which resulted in >91% extraction of TAG from yeast, bacteria, and microalgae. Experimental data was integrated into system models to evaluate the energetics of the processes compared to traditional extraction methods. The net energy ratio (NER) of a traditional dry solvent extraction is 0.84, whereas the approach presented here has a NER of 0.34 for yeast. PMID:25000397

  15. Iron sucrose accelerates early atherogenesis by increasing superoxide production and upregulating adhesion molecules in CKD.

    PubMed

    Kuo, Ko-Lin; Hung, Szu-Chun; Lee, Tzong-Shyuan; Tarng, Der-Cherng

    2014-11-01

    High-dose intravenous iron supplementation is associated with adverse cardiovascular outcomes in patients with CKD, but the underlying mechanism is unknown. Our study investigated the causative role of iron sucrose in leukocyte-endothelium interactions, an index of early atherogenesis, and subsequent atherosclerosis in the mouse remnant kidney model. We found that expression levels of intracellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) and adhesion of U937 cells increased in iron-treated human aortic endothelial cells through upregulated NADPH oxidase (NOx) and NF-?B signaling. We then measured mononuclear-endothelial adhesion and atherosclerotic lesions of the proximal aorta in male C57BL/6 mice with subtotal nephrectomy, male apolipoprotein E-deficient (ApoE(-/-)) mice with uninephrectomy, and sham-operated mice subjected to saline or parenteral iron loading. Iron sucrose significantly increased tissue superoxide production, expression of tissue cell adhesion molecules, and endothelial adhesiveness in mice with subtotal nephrectomy. Moreover, iron sucrose exacerbated atherosclerosis in the aorta of ApoE(-/-) mice with uninephrectomy. In patients with CKD, intravenous iron sucrose increased circulating mononuclear superoxide production, expression of soluble adhesion molecules, and mononuclear-endothelial adhesion compared with healthy subjects or untreated patients. In summary, iron sucrose aggravated endothelial dysfunction through NOx/NF-?B/CAM signaling, increased mononuclear-endothelial adhesion, and exacerbated atherosclerosis in mice with remnant kidneys. These results suggest a novel causative role for therapeutic iron in cardiovascular complications in patients with CKD. PMID:24722448

  16. Heavy-ion-induced sucrose radicals investigated using EPR and UV spectroscopy

    PubMed Central

    Nakagawa, Kouichi; Karakirova, Yordanka; Yordanov, Nicola D.

    2015-01-01

    The potential use of a sucrose dosimeter for estimating both linear energy transfer (LET) and the absorbed dose of heavy ion and X-ray radiation was investigated. The stable free radicals were produced when sucrose was irradiated with heavy ions, such as helium, carbon, silicon and neon ions, and when the X-ray radiation was similar to the obtained electron paramagnetic resonance (EPR) spectra, which were ?7 mT wide and composed of several hyperfine structures. In addition, the total spin concentration resulting from heavy-ion irradiation increased linearly as the absorbed dose increased, and decreased logarithmically as the LET increased. These empirical relations imply that the LET at a certain dose can be determined from the spin concentration. For sucrose and alanine, both cross-sections following C-ion irradiation with a 50 Gy dose were ?1.3 × 10?12 [?m2], taking into account the molecular size of the samples. The values of these cross-sections imply that multiple ionizing particles were involved in the production of stable radicals. Furthermore, UV absorbance at 267 nm of an aqueous solution of irradiated sucrose was found to linearly increase with increasing absorbed dose. Therefore, the EPR and UV results suggest that sucrose can be a useful dosimeter for heavy-ion irradiation. PMID:25480828

  17. Synthesis of fructooligosaccharides in banana 'prata' and its relation to invertase activity and sucrose accumulation.

    PubMed

    Der Agopian, Roberta Ghedini; Purgatto, Eduardo; Cordenunsi, Beatriz Rosana; Lajolo, Franco Maria

    2009-11-25

    Levels of sucrose and total fructooligosaccharides (FOS) were quantified in different phases of banana 'Prata' ripening during storage at ambient (approximately 19 degrees C) and low (approximately 10 degrees C) temperature. Total FOS levels were detected in the first days after harvest, whereas 1-kestose remained undetectable until the sucrose levels reached approximately 200 mg/g (dry weight) in both groups. Sucrose levels increased slowly but constantly at low temperature, but they elevated rapidly when the temperature was raised to 19 degrees C. Total FOS and sucrose levels were higher in bananas stored at low temperature than in the control group. In both samples, total FOS levels were higher than those of 1-kestose. The carbohydrate profiles obtained by HPLC and TLC suggest the presence of neokestose, 6-kestose, and bifurcose. The enzymes putatively involved in banana fructosyltransferase activity were also evaluated. Results obtained indicate that the banana enzyme responsible for the synthesis of FOS by transfructosylation is an invertase rather than a sucrose-sucrosyl transferase-like enzyme. PMID:19860446

  18. Electrospun gelatin nanofibers: a facile cross-linking approach using oxidized sucrose.

    PubMed

    Jalaja, K; James, Nirmala R

    2015-02-01

    Gelatin nanofibers were fabricated via electrospinning with minimal toxicity from solvents and cross-linking agents. Electrospinning was carried out using a solvent system based on water and acetic acid (8:2, v/v). Acetic acid concentration was kept as minimum as possible to reduce the toxic effects. Electrospun gelatin nanofibers were cross-linked with oxidized sucrose. Sucrose was oxidized by periodate oxidation to introduce aldehyde functionality. Cross-linking with oxidized sucrose could be achieved without compromising the nanofibrous architecture. Cross-linked gelatin nanofibers maintained the fibrous morphology even after keeping in contact with aqueous medium. The morphology of the cross-linked nanofibrous mats was examined by scanning electron microscopy (SEM). Oxidized sucrose cross-linked gelatin nanofibers exhibited improved thermal and mechanical properties. The nanofibrous mats were evaluated for cytotoxicity and cell viability using L-929 fibroblast cells. The results confirmed that oxidized sucrose cross-linked gelatin nanofibers were non-cytotoxic towards L-929 cells with good cell viability. PMID:25478965

  19. Antisense repression of sucrose phosphate synthase in transgenic muskmelon alters plant growth and fruit development

    SciTech Connect

    Tian, Hongmei; Ma, Leyuan; Zhao, Cong; Hao, Hui; Gong, Biao [College of Horticulture Science and Engineering, State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong 271018 (China)] [College of Horticulture Science and Engineering, State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong 271018 (China); Yu, Xiyan, E-mail: yuxiyan@sdau.edu.cn [College of Horticulture Science and Engineering, State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong 271018 (China)] [College of Horticulture Science and Engineering, State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong 271018 (China); Wang, Xiufeng, E-mail: xfwang@sdau.edu.cn [College of Horticulture Science and Engineering, State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong 271018 (China)] [College of Horticulture Science and Engineering, State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong 271018 (China)

    2010-03-12

    To unravel the roles of sucrose phosphate synthase (SPS) in muskmelon (Cucumis melo L.), we reduced its activity in transgenic muskmelon plants by an antisense approach. For this purpose, an 830 bp cDNA fragment of muskmelon sucrose phosphate synthase was expressed in antisense orientation behind the 35S promoter of the cauliflower mosaic virus. The phenotype of the antisense plants clearly differed from that of control plants. The transgenic plant leaves were markedly smaller, and the plant height and stem diameter were obviously shorter and thinner. Transmission electron microscope observation revealed that the membrane degradation of chloroplast happened in transgenic leaves and the numbers of grana and grana lamella in the chloroplast were significantly less, suggesting that the slow growth and weaker phenotype of transgenic plants may be due to the damage of the chloroplast ultrastructure, which in turn results in the decrease of the net photosynthetic rate. The sucrose concentration and levels of sucrose phosphate synthase decreased in transgenic mature fruit, and the fruit size was smaller than the control fruit. Together, our results suggest that sucrose phosphate synthase may play an important role in regulating the muskmelon plant growth and fruit development.

  20. Continuous acidogenesis of sucrose, raffinose and vinasse using mineral kissiris as promoter.

    PubMed

    Lappa, Katerina; Kandylis, Panagiotis; Bekatorou, Argyro; Bastas, Nikolaos; Klaoudatos, Stavros; Athanasopoulos, Nikolaos; Kanellaki, Maria; Koutinas, Athanasios A

    2015-07-01

    The use of kissiris as promoter (culture immobilization carrier) in anaerobic acidogenesis of sucrose, raffinose and vinasse is reported. Initially, the effect of pH (4-8) and fermentation temperature (18-52°C) on the accumulation of low molecular weight organic acids (OAs) during sucrose acidogenesis, was evaluated. The promoting effect of kissiris was confirmed compared to free cells, resulting in 80% increased OAs production. The optimum conditions (pH 8; 37°C) were used during acidogenesis of sucrose/raffinose mixtures. A continuous system was also operated for more than 2months. When sucrose and sucrose/raffinose mixtures were used, lactic acid type fermentation prevailed, while when vinasse was used, butyric acid type fermentation occurred. Total OAs concentrations were more than 14g/L and ethanol concentrations were 0.5-1mL/L. Culture adaptation in vinasse was necessary to avoid poor results. The proposed process is promising for new generation ester-based biofuel production from industrial wastes. PMID:25748017

  1. Heavy-ion-induced sucrose radicals investigated using EPR and UV spectroscopy.

    PubMed

    Nakagawa, Kouichi; Karakirova, Yordanka; Yordanov, Nicola D

    2015-05-01

    The potential use of a sucrose dosimeter for estimating both linear energy transfer (LET) and the absorbed dose of heavy ion and X-ray radiation was investigated. The stable free radicals were produced when sucrose was irradiated with heavy ions, such as helium, carbon, silicon and neon ions, and when the X-ray radiation was similar to the obtained electron paramagnetic resonance (EPR) spectra, which were ?7 mT wide and composed of several hyperfine structures. In addition, the total spin concentration resulting from heavy-ion irradiation increased linearly as the absorbed dose increased, and decreased logarithmically as the LET increased. These empirical relations imply that the LET at a certain dose can be determined from the spin concentration. For sucrose and alanine, both cross-sections following C-ion irradiation with a 50 Gy dose were ?1.3 × 10(-12) [?m(2)], taking into account the molecular size of the samples. The values of these cross-sections imply that multiple ionizing particles were involved in the production of stable radicals. Furthermore, UV absorbance at 267 nm of an aqueous solution of irradiated sucrose was found to linearly increase with increasing absorbed dose. Therefore, the EPR and UV results suggest that sucrose can be a useful dosimeter for heavy-ion irradiation. PMID:25480828

  2. Biochemical comparison of plaque fluid on tooth and acrylic surfaces during a sucrose challenge.

    PubMed

    Rankine, C A; Smith, S L; Schneider, P E; Gardiner, D M

    1996-07-01

    Previous studies have investigated variations in dental plaque fluid composition within a single mouth after a sucrose exposure. The purpose of this study was to determine a potential source of calcium and phosphorus in plaque by comparing the pH, calcium and phosphorus concentrations in plaque fluid obtained from an acrylic appliance with samples taken from supragingival tooth surfaces within the same individual after a sucrose challenge. Separate plaque samples from 14 individuals were collected from an acrylic appliance or tooth surfaces within same individual before and 15 min after a 20% sucrose rinse. Each plaque sample was centrifuged and nanolitre samples of plaque fluid were analysed for pH with a pH microelectrode, for total calcium concentration by atomic absorption in a graphite furnace, and for phosphorus concentration by spectrophotometry. There was an increase in the calcium and phosphorus concentration in the plaque after the sucrose challenge and a significant increase in calcium and phosphorus concentrations in the plaque taken from the teeth compared to the acrylic surfaces. The results indicate that the increased total calcium and phosphorus in plaque during a sucrose challenge is probably derived from the demineralization of enamel or extracellular demineralized components. PMID:9015571

  3. Comparative effects of various naturally occurring cannabinoids on food, sucrose and water consumption by rats.

    PubMed

    Sofia, R D; Knobloch, L C

    1976-05-01

    The effects of intraperitoneally injected detla9-tetrahydrocannabinol (THC), cannabinol (CBN) and cannabidiol (CBD) were compared to d-amphetamine sulfate (d-AMP) on food and water consumption and intake of two different concentrations of sucrose solutions. Three groups of rats were given the following dietary regimens within a 6-hr feed period day: 1 - water and dry food; 2 - water, dry food and five percent sucrose solution; 3 - water, dry food and 20% sucrose solution. Food and water consumption were dramatically reduced by each test drug at feeding periods immediately following and in some instances up to 4 days after dosing in all 3 groups. However, sucrose consumption was much less affected by each cannabinoid, inidcating a preference for sweet calories, whereas d-AMP had an equal anorexic action on both food and sucrose consumption. These data suggest for the first time in rats that a preference for sweet calories occurs during an overall anorexic effect of THC, CBN and CBD. PMID:951436

  4. Effects of sucrose and sorbitol on cement-based stabilization/solidification of toxic metal waste.

    PubMed

    Zhang, Linghong; Catalan, Lionel J J; Larsen, Andrew C; Kinrade, Stephen D

    2008-03-01

    The effects of sucrose or sorbitol addition on the hydration, unconfined compressive strength and leachability of Portland cement pastes containing 1% Pb and 1% Zn were studied as a function of time. Whereas Pb and Zn were found to shorten the time to achieve maximum hydration of Portland cement, the combination of these metals with 0.15 wt% sucrose or 0.40 wt% sorbitol retarded the setting of cement by at least 7 and 28 days, respectively, without affecting the strength at 56 days. The leachability of Pb and Zn evaluated by the TCLP 1311 protocol at 56 and 71 days was slightly reduced or unchanged by the addition of sucrose or sorbitol. SEM-EDS and XRD analyses revealed that ettringite precipitation was favored whereas the formation of CSH gel, which accounts for most of the strength of hydrated cement, was delayed in cement pastes containing both metals and sucrose or sorbitol. These results indicate that controlled additions of sucrose or sorbitol can add flexibility to the handling of cement-treated metal waste, particularly when it needs to be transported by truck or pipeline between the treatment plant and the disposal site, without affecting its long-term performance. PMID:17629400

  5. Production of malt extract and beer from Nigerian sorghum varieties

    Microsoft Academic Search

    F. J. C Odibo; L. N Nwankwo; R. C Agu

    2002-01-01

    Two sorghum varieties were studied with a view to producing wort and evaporated wort (extract), in the form that the extract could keep for a longer period and used for brewing when required. When mashed using commercial brewing enzymes, the sorghum samples produced sufficient sugars and amino acids required for yeast growth and alcohol production during fermentation. Fermentation studies showed

  6. Green tea, black tea, and oolong tea polyphenols reduce visceral fat and inflammation in mice fed high-fat, high-sucrose obesogenic diets.

    PubMed

    Heber, David; Zhang, Yanjun; Yang, Jieping; Ma, Janice E; Henning, Susanne M; Li, Zhaoping

    2014-09-01

    Green tea (GT) and caffeine in combination were shown to increase energy expenditure and fat oxidation, but less is known about the effects of black tea (BT) and oolong tea (OT). This study investigated whether decaffeinated polyphenol extracts from GT, BT, and OT decrease body fat and inflammation in male C57BL/6J mice fed high-fat/high-sucrose [HF/HS (32% energy from fat, 25% energy from sucrose)] diets. Mice were fed either an HF/HS diet with 0.25% of polyphenol from GT, OT, or BT or a low-fat/high-sucrose [LF/HS (10.6% energy from fat, 25% energy from sucrose)] diet for 20 wk. Monomeric tea polyphenols were found in the liver and adipose tissue of mice fed the HF/HS diet with GT polyphenols (GTPs) and OT polyphenols (OTPs) but not BT polyphenols (BTPs). Treatment with GTPs, OTPs, BTPs, and an LF/HS diet led to significantly lower body weight, total visceral fat volume by MRI, and liver lipid weight compared with mice in the HF/HS control group. Only GTPs reduced food intake significantly by ?10%. GTP, BTP, and LF/HS-diet treatments significantly reduced serum monocyte chemotactic protein-1 (MCP-1) compared with HF/HS controls. In mesenteric fat, monocyte chemotactic protein-1 (Mcp1) gene expression was significantly decreased by treatment with GTPs, BTPs, OTPs, and an LF/HS diet and in liver tissue by GTP and BTP treatments. Mcp1 gene expression in epididymal fat was significantly decreased by the BTP and LF/HS diet interventions. In epididymal fat, consistent with an anti-inflammatory effect, adiponectin gene expression was significantly increased by GTPs and OTPs. Angiogenesis during adipose tissue expansion is anti-inflammatory by maintaining adipocyte perfusion. We observed significantly increased gene expression of vascular endothelial growth factor A by GTPs and vascular endothelial growth factor receptor 2 by BTPs and the LF/HS diet and a decrease in pigment epithelium-derived factor gene expression by OTPs and BTPs. In summary, all 3 tea polyphenol extracts induced weight loss and anti-inflammatory and angiogenic effects, although the tissue content of polyphenols differed significantly. PMID:25031332

  7. Yeast ?-Glucosidase Inhibitory Phenolic Compounds Isolated from Gynura medica Leaf

    PubMed Central

    Tan, Chao; Wang, Qunxing; Luo, Chunhua; Chen, Sai; Li, Qianyuan; Li, Peng

    2013-01-01

    Gynura medica leaf extract contains significant amounts of flavonols and phenolic acids and exhibits powerful hypoglycemic activity against diabetic rats in vivo. However, the hypoglycemic active constituents that exist in the plant have not been fully elaborated. The purpose of this study is to isolate and elaborate the hypoglycemic activity compounds against inhibition the yeast ?-glucosidase in vitro. Seven phenolic compounds including five flavonols and two phenolic acids were isolated from the leaf of G. medica. Their structures were identified by the extensive NMR and mass spectral analyses as: kaempferol (1), quercetin (2), kaempferol-3-O-?-D-glucopyranoside (3), kaempferol-3-O-rutinoside (4), rutin (5), chlorogenic acid (6) and 3,5-dicaffeoylquinic acid methyl ester (7). All of the compounds except 1 and 3 were isolated for the first time from G. medica. Compounds 1–7 were also assayed for their hypoglycemic activity against yeast ?-glucosidase in vitro. All of the compounds except 1 and 6 showed good yeast ?-glucosidase inhibitory activity with the IC50 values of 1.67 mg/mL, 1.46 mg/mL, 0.38 mg/mL, 0.10 mg/mL and 0.53 mg/mL, respectively. PMID:23358246

  8. Architecture of a yeast U6 RNA gene promoter.

    PubMed Central

    Eschenlauer, J B; Kaiser, M W; Gerlach, V L; Brow, D A

    1993-01-01

    The promoters of vertebrate and yeast U6 small nuclear RNA genes are structurally dissimilar, although both are recognized by RNA polymerase III. Vertebrate U6 RNA genes have exclusively upstream promoters, while the U6 RNA gene from the yeast Saccharomyces cerevisiae (SNR6) has internal and downstream promoter elements that match the tRNA gene intragenic A- and B-block elements, respectively. Substitution of the SNR6 A or B block greatly diminished U6 RNA accumulation in vivo, and a subcellular extract competent for RNA polymerase III transcription generated nearly identical DNase I protection patterns over the SNR6 downstream B block and a tRNA gene intragenic B block. We conclude that the SNR6 promoter is functionally similar to tRNA gene promoters, although the effects of extragenic deletion mutations suggest that the downstream location of the SNR6 B block imposes unique positional constraints on its function. Both vertebrate and yeast U6 RNA genes have an upstream TATA box element not normally found in tRNA genes. Substitution of the SNR6 TATA box altered the site of transcription initiation in vivo, while substitution of sequences further upstream had no effect on SNR6 transcription. We present a model for the SNR6 transcription complex that explains these results in terms of their effects on the binding of transcription initiation factor TFIIIB. Images PMID:8474459

  9. Propylene Glycol and Ethoxylated Surfactant Effects on the Phase Behavior of Water\\/Sucrose Stearate\\/Oil System

    Microsoft Academic Search

    Monzer Fanun

    2007-01-01

    In this work, we studied the phase behavior as function of temperature of water\\/sucrose stearate\\/propylene glycol\\/oil and water\\/sucrose stearate\\/ethoxylated mono?di?glyceride\\/oil systems. The oils were R (+)?limonene, isopropylmyristate, and caprylic?capric triglyceride. It was found that adding propylene glycol and ethoxylated mono?di?glyceride to the water\\/sucrose stearate\\/R (+)?limonene and water\\/sucrose stearate\\/isopropylmyristate systems decreases the temperature and surfactants concentration needed for the formation of

  10. A complete assignment of the vibrational spectra of sucrose in aqueous medium based on the SQM methodology and SCRF calculations.

    PubMed

    Brizuela, Alicia Beatriz; Castillo, María Victoria; Raschi, Ana Beatriz; Davies, Lilian; Romano, Elida; Brandán, Silvia Antonia

    2014-03-31

    In the present study, a complete assignment of the vibrational spectra of sucrose in aqueous medium was performed combining Pulay's Scaled Quantum Mechanics Force Field (SQMFF) methodology with self-consistent reaction field (SCRF) calculations. Aqueous saturated solutions of sucrose and solutions at different molar concentrations of sucrose in water were completely characterized by infrared, HATR, and Raman spectroscopies. In accordance with reported data of the literature for sucrose, the theoretical structures of sucrose penta and sucrose dihydrate were also optimized in gas and aqueous solution phases by using the density functional theory (DFT) calculations. The solvent effects for the three studied species were analyzed using the solvation PCM/SMD model and, then, their corresponding solvation energies were predicted. The presence of pure water, sucrose penta-hydrate, and sucrose dihydrate was confirmed by using theoretical calculations based on the hybrid B3LYP/6-31G(?) method and the experimental vibrational spectra. The existence of both sucrose hydrate complexes in aqueous solution is evidenced in the IR and HATR spectra by means of the characteristic bands at 3388, 3337, 3132, 1648, 1375, 1241, 1163, 1141, 1001, 870, 851, 732, and 668cm(-1) while in the Raman spectrum, the groups of bands in the regions 3159-3053cm(-1), 2980, 2954, and 1749-1496cm(-1) characterize the vibration modes of those complexes. The inter and intra-molecular H bond formations in aqueous solution were studied by Natural Bond Orbital (NBO) and Atoms in Molecules theory (AIM) investigation. PMID:24632216

  11. Characterization of the Yeast Transcriptome

    Microsoft Academic Search

    Victor E. Velculescu; Lin Zhang; Wei Zhou; Jacob Vogelstein; Munira A. Basrai; Douglas E Bassett; Phil Hieter; Bert Vogelstein; Kenneth W. Kinzler

    1997-01-01

    We have analyzed the set of genes expressed from the yeast genome, herein called the transcriptome, using serial analysis of gene expression. Analysis of 60,633 transcripts revealed 4,665 genes, with expression levels ranging from 0.3 to over 200 transcripts per cell. Of these genes, 1981 had known functions, while 2684 were previously uncharacterized. The integration of positional information with gene

  12. Malassezia Baillon, emerging clinical yeasts.

    PubMed

    Batra, Roma; Boekhout, Teun; Guého, Eveline; Cabañes, F Javier; Dawson, Thomas L; Gupta, Aditya K

    2005-12-01

    The human and animal pathogenic yeast genus Malassezia has received considerable attention in recent years from dermatologists, other clinicians, veterinarians and mycologists. Some points highlighted in this review include recent advances in the technological developments related to detection, identification, and classification of Malassezia species. The clinical association of Malassezia species with a number of mammalian dermatological diseases including dandruff, seborrhoeic dermatitis, pityriasis versicolor, psoriasis, folliculitis and otitis is also discussed. PMID:16084129

  13. An RT-qPCR approach to study the expression of genes responsible for sugar assimilation during rehydration of active dry yeast.

    PubMed

    Vaudano, Enrico; Costantini, Antonella; Noti, Olta; Garcia-Moruno, Emilia

    2010-09-01

    A short reactivation period in aqueous media is required for active dry yeast (ADY) to be utilised in winemaking. Rehydration restores the active metabolic conditions necessary for good fermentative and competitive abilities. We used a reverse transcription-quantitative PCR (RT-qPCR) method with relative quantification to investigate the expression of seven hexose transporter genes (HXT1-7) and one invertase-encoding gene (SUC2) during ADY rehydration in water with or without sucrose. For this, seven candidate reference genes were evaluated, and the three most stably expressed genes were selected and used for mRNA normalisation. The results show that, during the rehydration in the presence of sucrose, yeast cells are able to immediately hydrolyse this sugar into glucose and fructose as soon as they are introduced in the medium. Subsequently, differential glucose/fructose uptake occurs, which is mediated by hexose transporters. At the transcriptomic level, there is a strong induction of the high-affinity transporters, HXT2 and HXT4, and the low-affinity transporters, HXT3 and HXT1, when ADY is rehydrated with sucrose, while HXT5 and HXT6/7 are expressed at high levels with a moderate tendency to decrease. In water, the HXT2 gene was the only one of the transporter genes studied that showed significant variations. These results suggest that during rehydration, expression is not simply regulated by the affinity to hexose but is also controlled by other mechanisms that allow the cell to bypass glucose control. Moreover, the expression of SUC2 showed little variation in media with sucrose, suggesting that other invertases and/or posttranscriptional controls exist. PMID:20630323

  14. Yeast diversity in hypersaline habitats.

    PubMed

    Butinar, L; Santos, S; Spencer-Martins, I; Oren, A; Gunde-Cimerman, N

    2005-03-15

    Thus far it has been considered that hypersaline natural brines which are subjected to extreme solar heating, do not contain non-melanized yeast populations. Nevertheless we have isolated yeasts in eight different salterns worldwide, as well as from the Dead Sea, Enriquillo Lake (Dominican Republic) and the Great Salt Lake (Utah). Among the isolates obtained from hypersaline waters, Pichia guilliermondii, Debaryomyces hansenii, Yarrowia lipolytica and Candida parapsilosis are known contaminants of low water activity food, whereas Rhodosporidium sphaerocarpum, R. babjevae, Rhodotorula laryngis, Trichosporon mucoides, and a new species resembling C. glabrata were not known for their halotolerance and were identified for the first time in hypersaline habitats. Moreover, the ascomycetous yeast Metschnikowia bicuspidata, known to be a parasite of the brine shrimp, was isolated as a free-living form from the Great Salt Lake brine. In water rich in magnesium chloride (bitterns) from the La Trinitat salterns (Spain), two new species provisionally named C. atmosphaerica - like and P. philogaea - like were discovered. PMID:15766773

  15. Yeasts Diversity in Fermented Foods and Beverages

    NASA Astrophysics Data System (ADS)

    Tamang, Jyoti Prakash; Fleet, Graham H.

    People across the world have learnt to culture and use the essential microorganisms for production of fermented foods and alcoholic beverages. A fermented food is produced either spontaneously or by adding mixed/pure starter culture(s). Yeasts are among the essential functional microorganisms encountered in many fermented foods, and are commercially used in production of baker's yeast, breads, wine, beer, cheese, etc. In Asia, moulds are predominant followed by amylolytic and alcohol-producing yeasts in the fermentation processes, whereas in Africa, Europe, Australia and America, fermented products are prepared exclusively using bacteria or bacteria-yeasts mixed cultures. This chapter would focus on the varieties of fermented foods and alcoholic beverages produced by yeasts, their microbiology and role in food fermentation, widely used commercial starters (pilot production, molecular aspects), production technology of some common commercial fermented foods and alcoholic beverages, toxicity and food safety using yeasts cultures and socio-economy

  16. Characterization of the AINV gene and the encoded invertase from the dimorphic yeast Arxula adeninivorans.

    PubMed

    Böer, Erik; Wartmann, Thomas; Luther, Bianka; Manteuffel, Renate; Bode, Rüdiger; Gellissen, Gerd; Kunze, Gotthard

    2004-08-01

    The invertase-encoding of AINV gene Arxula adeninivorans was isolated and characterized. The gene includes a coding sequence of 2700 bp encoding a putative 899 amino acid protein of 101.7 kDa. The identity of the gene was confirmed by a high degree of homology of the derived amino acid sequence to that of alpha-glucosidases from different sources. The gene activity is regulated by carbon source. In media supplemented with sucrose induction of the AINV gene and accumulation of the encoded invertase in the medium was observed. In addition the extracellular enzyme level is influenced by the morphological status of the organism, with mycelia secreting the enzyme in titres higher than those observed in budding yeasts. The enzyme characteristics were analysed from isolates of native strains as well as from those of recombinant strains expressing the AINV gene under control of the strong A. adeninivorans -derived TEF1 promoter. For both proteins a molecular mass of 600 kDa was determined, a pH optimum at pH 4.5 and a temperature optimum at 55 degrees C. The preferred substrates for the enzyme included the ss-D-fructofuranosides sucrose, inulin and raffinose. Only a weak enzyme activity was observed for the alpha-D-glucopyranosides maltotriose, maltose and isomaltose. Thus the invertase primarily is a ss-fructosidase and not an alpha-glucosidase as suggested by the homology to such enzymes. PMID:15280646

  17. Use of waste Chinese cabbage as a substrate for yeast biomass production.

    PubMed

    Choi, Min Ho; Ji, Geun Eog; Koh, Kyung Hee; Ryu, Yeon Woo; Jo, Do Hyun; Park, Yun Hee

    2002-07-01

    The possibility of using waste Chinese cabbage (Brassica campestris) as a substrate for microbial biomass production was investigated. The juice from waste Chinese cabbage contains relatively high amounts of reducing sugars suitable for yeast culture. The cell mass and protein content of four species of yeast, Candida utilis, Pichia stipitis, Kluyveromyces marxianus, and Saccharomyces cerevisiae, were determined when cultured in juice extracted from cabbage waste. Compared to YM broth containing the same level of sugar, all the strains except C. utilis showed higher total protein production in cabbage juice medium (CJM). PMID:12094802

  18. Assembly of eukaryotic algal chromosomes in yeast

    PubMed Central

    2013-01-01

    Background Synthetic genomic approaches offer unique opportunities to use powerful yeast and Escherichia coli genetic systems to assemble and modify chromosome-sized molecules before returning the modified DNA to the target host. For example, the entire 1 Mb Mycoplasma mycoides chromosome can be stably maintained and manipulated in yeast before being transplanted back into recipient cells. We have previously demonstrated that cloning in yeast of large (>?~?150 kb), high G?+?C (55%) prokaryotic DNA fragments was improved by addition of yeast replication origins every ~100 kb. Conversely, low G?+?C DNA is stable (up to at least 1.8 Mb) without adding supplemental yeast origins. It has not been previously tested whether addition of yeast replication origins similarly improves the yeast-based cloning of large (>150 kb) eukaryotic DNA with moderate G?+?C content. The model diatom Phaeodactylum tricornutum has an average G?+?C content of 48% and a 27.4 Mb genome sequence that has been assembled into chromosome-sized scaffolds making it an ideal test case for assembly and maintenance of eukaryotic chromosomes in yeast. Results We present a modified chromosome assembly technique in which eukaryotic chromosomes as large as ~500 kb can be assembled from cloned ~100 kb fragments. We used this technique to clone fragments spanning P. tricornutum chromosomes 25 and 26 and to assemble these fragments into single, chromosome-sized molecules. We found that addition of yeast replication origins improved the cloning, assembly, and maintenance of the large chromosomes in yeast. Furthermore, purification of the fragments to be assembled by electroelution greatly increased assembly efficiency. Conclusions Entire eukaryotic chromosomes can be successfully cloned, maintained, and manipulated in yeast. These results highlight the improvement in assembly and maintenance afforded by including yeast replication origins in eukaryotic DNA with moderate G?+?C content (48%). They also highlight the increased efficiency of assembly that can be achieved by purifying fragments before assembly. PMID:24325901

  19. Yeasts in floral nectar: a quantitative survey

    PubMed Central

    Herrera, Carlos M.; de Vega, Clara; Canto, Azucena; Pozo, María I.

    2009-01-01

    Background and Aims One peculiarity of floral nectar that remains relatively unexplored from an ecological perspective is its role as a natural habitat for micro-organisms. This study assesses the frequency of occurrence and abundance of yeast cells in floral nectar of insect-pollinated plants from three contrasting plant communities on two continents. Possible correlations between interspecific differences in yeast incidence and pollinator composition are also explored. Methods The study was conducted at three widely separated areas, two in the Iberian Peninsula (Spain) and one in the Yucatán Peninsula (Mexico). Floral nectar samples from 130 species (37–63 species per region) in 44 families were examined microscopically for the presence of yeast cells. For one of the Spanish sites, the relationship across species between incidence of yeasts in nectar and the proportion of flowers visited by each of five major pollinator categories was also investigated. Key Results Yeasts occurred regularly in the floral nectar of many species, where they sometimes reached extraordinary densities (up to 4 × 105 cells mm?3). Depending on the region, between 32 and 44 % of all nectar samples contained yeasts. Yeast cell densities in the order of 104 cells mm?3 were commonplace, and densities >105 cells mm?3 were not rare. About one-fifth of species at each site had mean yeast cell densities >104 cells mm?3. Across species, yeast frequency and abundance were directly correlated with the proportion of floral visits by bumble-bees, and inversely with the proportion of visits by solitary bees. Conclusions Incorporating nectar yeasts into the scenario of plant–pollinator interactions opens up a number of intriguing avenues for research. In addition, with yeasts being as ubiquitous and abundant in floral nectars as revealed by this study, and given their astounding metabolic versatility, studies focusing on nectar chemical features should carefully control for the presence of yeasts in nectar samples. PMID:19208669

  20. Production of lactosucrose from sucrose and lactose by a levansucrase from Zymomonas mobilis.

    PubMed

    Han, Woo-Cheul; Byun, Sun-Ho; Kim, Mi-Hyun; Sohn, Eun Hwa; Lim, Jung Dae; Um, Byung Hun; Kim, Chul Ho; Kang, Soon Ah; Jang, Ki-Hyo

    2009-10-01

    Lactosucrose (4(G)-beta-D-galactosylsucrose) is an oligosaccharide consisting of galactose, glucose, and fructose. In this study, we prepared lactosucrose from lactose and sucrose using a levansucrase derived from Zymomonas mobilis. Optimum conditions for lactosucrose formation were 23 degrees C, pH 7.0, 18.0% (w/v) lactose monohydrate, and 18% (w/v) sucrose as substrates, and 1 unit of enzyme/ml of reaction mixture. Under these conditions, the lactosucrose conversion efficiency was 28.5%. The product was purified and confirmed to be O-beta-D-galactopyranosyl-(1-->4)-O-beta-D-glucopyranosyl- (1-->2)-beta-D-fructofuranoside, or lactosucrose. A mixed-enzyme system containing a levansucrase and a glucose oxidase was applied in order to increase the efficiency of lactose and sucrose conversion to lactosucrose, which rose to 43.2% as s result. PMID:19884774

  1. Sucrose and invertases, a part of the plant defense response to the biotic stresses.

    PubMed

    Tauzin, Alexandra S; Giardina, Thierry

    2014-01-01

    Sucrose is the main form of assimilated carbon which is produced during photosynthesis and then transported from source to sink tissues via the phloem. This disaccharide is known to have important roles as signaling molecule and it is involved in many metabolic processes in plants. Essential for plant growth and development, sucrose is engaged in plant defense by activating plant immune responses against pathogens. During infection, pathogens reallocate the plant sugars for their own needs forcing the plants to modify their sugar content and triggering their defense responses. Among enzymes that hydrolyze sucrose and alter carbohydrate partitioning, invertases have been reported to be affected during plant-pathogen interactions. Recent highlights on the role of invertases in the establishment of plant defense responses suggest a more complex regulation of sugar signaling in plant-pathogen interaction. PMID:25002866

  2. Evaluation of Automated Yeast Identification System

    NASA Technical Reports Server (NTRS)

    McGinnis, M. R.

    1996-01-01

    One hundred and nine teleomorphic and anamorphic yeast isolates representing approximately 30 taxa were used to evaluate the accuracy of the Biolog yeast identification system. Isolates derived from nomenclatural types, environmental, and clinica isolates of known identity were tested in the Biolog system. Of the isolates tested, 81 were in the Biolog database. The system correctly identified 40, incorrectly identified 29, and was unable to identify 12. Of the 28 isolates not in the database, 18 were given names, whereas 10 were not. The Biolog yeast identification system is inadequate for the identification of yeasts originating from the environment during space program activities.

  3. Iron Sucrose Promotes Endothelial Injury and Dysfunction and Monocyte Adhesion/Infiltration

    PubMed Central

    Kamanna, Vaijinath S.; Ganji, Shobha H.; Shelkovnikov, Stanislav; Norris, Keith; Vaziri, Nosratola D.

    2012-01-01

    Background/Aims Intravenous (IV) iron preparations are widely used in the management of anemia in ESRD populations. Recent changes in reimbursement policy have dramatically increased the use of IV iron to lower the use of costly erythropoiesis-stimulating agents. These preparations are frequently administered with insufficient attention to the total body iron stores or presence of inflammation which is aggravated by excess iron. Endothelial injury and dysfunction are critical steps in atherosclerosis, thrombosis and cardiovascular disease. IV iron preparations raise plasma non-transferrin-bound iron which can promote oxidative stress, endothelial damage and dysfunction. We explored the effect of an IV iron preparation on endothelial cells, monocytes and isolated arteries. Methods Primary cultures of human aortic endothelial cells (HAEC) were treated with pharmacologically relevant concentrations of iron sucrose (10–100 ?g/ml) for 4–24 h. Endothelial cell morphology, viability, and monocyte adhesion were tested. Endothelial function was assessed by measuring the vasorelaxation response to acetylcholine in normal rat thoracic aorta rings preincubated with iron sucrose (200 ?g/ml). Results In contrast to the control HAEC which showed normal cobblestone appearance, cells treated with iron sucrose (50–100 ?g/ml) for 4 h showed loss of normal morphological characteristics, cellular fragmentation, shrinkage, detachment, monolayer disruption and nuclear condensation/fragmentation features signifying apoptosis. HAEC exposure to iron sucrose (10–100 ?g/ml) increased monocyte adhesion 5- to 25-fold. Incubation in media containing 200 ?g/ml iron sucrose for 3 h caused marked reduction in the acetylcholine-mediated relaxation in phenylephrine-precontracted rat aorta. Conclusion Pharmacologically relevant concentration of iron sucrose results in endothelial injury and dysfunction and marked increase in monocyte adhesion. PMID:22212390

  4. Single amino acids in sucrose rewards modulate feeding and associative learning in the honeybee.

    PubMed

    Simcock, Nicola K; Gray, Helen E; Wright, Geraldine A

    2014-10-01

    Obtaining the correct balance of nutrients requires that the brain integrates information about the body's nutritional state with sensory information from food to guide feeding behaviour. Learning is a mechanism that allows animals to identify cues associated with nutrients so that they can be located quickly when required. Feedback about nutritional state is essential for nutrient balancing and could influence learning. How specific this feedback is to individual nutrients has not often been examined. Here, we tested how the honeybee's nutritional state influenced the likelihood it would feed on and learn sucrose solutions containing single amino acids. Nutritional state was manipulated by pre-feeding bees with either 1M sucrose or 1M sucrose containing 100mM of isoleucine, proline, phenylalanine, or methionine 24h prior to olfactory conditioning of the proboscis extension response. We found that bees pre-fed sucrose solution consumed less of solutions containing amino acids and were also less likely to learn to associate amino acid solutions with odours. Unexpectedly, bees pre-fed solutions containing an amino acid were also less likely to learn to associate odours with sucrose the next day. Furthermore, they consumed more of and were more likely to learn when rewarded with an amino acid solution if they were pre-fed isoleucine and proline. Our data indicate that single amino acids at relatively high concentrations inhibit feeding on sucrose solutions containing them, and they can act as appetitive reinforcers during learning. Our data also suggest that select amino acids interact with mechanisms that signal nutritional sufficiency to reduce hunger. Based on these experiments, we predict that nutrient balancing for essential amino acids during learning requires integration of information about several amino acids experienced simultaneously. PMID:24819203

  5. Invertase-nanogold clusters decorated plant membranes for fluorescence-based sucrose sensor.

    PubMed

    Bagal-Kestwal, Dipali; Kestwal, Rakesh Mohan; Chiang, Been-Huang

    2015-01-01

    In the present study, invertase-mediated nanogold clusters were synthesized on onion membranes, and their application for sucrose biosensor fabrication was investigated. Transmission electron microscopy revealed free nanoparticles of various sizes (diameter ~5 to 50 nm) along with clusters of nanogold (~95 to 200 nm) on the surface of inner epidermal membranes of onions (Allium cepa L.). Most of the polydispersed nanoparticles were spherical, although some were square shaped, triangular, hexagonal or rod-shaped. Ultraviolet-visible spectrophotometric observations showed the characteristic peak for nanoparticles decorated invertase-onion membrane at approximately 301 nm. When excited at 320 nm in the presence of sucrose, the membranes exhibited a photoemission peak at 348 nm. The fluorescence lifetime of this nanogold modified onion membrane was 6.20 ns, compared to 2.47 ns for invertase-onion membrane without nanogold. Therefore, a sucrose detection scheme comprised of an invertase/nanogold decorated onion membrane was successfully developed. This fluorescent nanogold-embedded onion membrane drop-test sensor exhibited wide acidic to neutral working pH range (4.0-7.0) with a response time 30 seconds (<1 min). The fabricated quenching-based probe had a low detection limit (2x10(-9) M) with a linear dynamic range of 2.25x10(-9) to 4.25x10(-8) M for sensing sucrose. A microplate designed with an enzyme-nanomaterial-based sensor platform exhibited a high compliance, with acceptable percentage error for the detection of sucrose in green tea samples in comparison to a traditional method. With some further, modifications, this fabricated enzyme-nanogold onion membrane sensor probe could be used to estimate glucose concentrations for a variety of analytical samples. Graphical abstract Synthesis and characterization of invertase assisted nanogold clusters on onion membranes and their application for fluorescence-based sucrose sensor. PMID:25886379

  6. Trehalulose synthase native and carbohydrate complexed structures provide insights into sucrose isomerization.

    PubMed

    Ravaud, Stéphanie; Robert, Xavier; Watzlawick, Hildegard; Haser, Richard; Mattes, Ralf; Aghajari, Nushin

    2007-09-21

    Various diseases related to the overconsumption of sugar make a growing need for sugar substitutes. Because sucrose is an inexpensive and readily available d-glucose donor, the industrial potential for enzymatic synthesis of the sucrose isomers trehalulose and/or isomaltulose from sucrose is large. The product specificity of sucrose isomerases that catalyze this reaction depends essentially on the possibility for tautomerization of sucrose, which is required for trehalulose formation. For optimal use of the enzyme, targeting controlled synthesis of these functional isomers, it is necessary to minimize the side reactions. This requires an extensive analysis of substrate binding modes and of the specificity-determining sites in the structure. The 1.6-2.2-A resolution three-dimensional structures of native and mutant complexes of a trehalulose synthase from Pseudomonas mesoacidophila MX-45 mimic successive states of the enzyme reaction. Combined with mutagenesis studies they give for the first time thorough insights into substrate recognition and processing and reaction specificities of these enzymes. Among the important outcomes of this study is the revelation of an aromatic clamp defined by Phe(256) and Phe(280) playing an essential role in substrate recognition and in controlling the reaction specificity, which is further supported by mutagenesis studies. Furthermore, this study highlights essential residues for binding the glucosyl and fructosyl moieties. The introduction of subtle changes informed by comparative three-dimensional structural data observed within our study can lead to fundamental modifications in the mode of action of sucrose isomerases and hence provide a template for industrial catalysts. PMID:17597061

  7. Single amino acids in sucrose rewards modulate feeding and associative learning in the honeybee

    PubMed Central

    Simcock, Nicola K.; Gray, Helen E.; Wright, Geraldine A.

    2014-01-01

    Obtaining the correct balance of nutrients requires that the brain integrates information about the body’s nutritional state with sensory information from food to guide feeding behaviour. Learning is a mechanism that allows animals to identify cues associated with nutrients so that they can be located quickly when required. Feedback about nutritional state is essential for nutrient balancing and could influence learning. How specific this feedback is to individual nutrients has not often been examined. Here, we tested how the honeybee’s nutritional state influenced the likelihood it would feed on and learn sucrose solutions containing single amino acids. Nutritional state was manipulated by pre-feeding bees with either 1 M sucrose or 1 M sucrose containing 100 mM of isoleucine, proline, phenylalanine, or methionine 24 h prior to olfactory conditioning of the proboscis extension response. We found that bees pre-fed sucrose solution consumed less of solutions containing amino acids and were also less likely to learn to associate amino acid solutions with odours. Unexpectedly, bees pre-fed solutions containing an amino acid were also less likely to learn to associate odours with sucrose the next day. Furthermore, they consumed more of and were more likely to learn when rewarded with an amino acid solution if they were pre-fed isoleucine and proline. Our data indicate that single amino acids at relatively high concentrations inhibit feeding on sucrose solutions containing them, and they can act as appetitive reinforcers during learning. Our data also suggest that select amino acids interact with mechanisms that signal nutritional sufficiency to reduce hunger. Based on these experiments, we predict that nutrient balancing for essential amino acids during learning requires integration of information about several amino acids experienced simultaneously. PMID:24819203

  8. Analysis of sucrose accumulation in the sugar cane culm on the basis of in vitro kinetic data.

    PubMed

    Rohwer, J M; Botha, F C

    2001-09-01

    Sucrose accumulation in developing sugar cane (Saccharum officinarum) is accompanied by a continuous synthesis and cleavage of sucrose in the storage tissues. Despite numerous studies, the factors affecting sucrose accumulation are still poorly understood, and no consistent pattern has emerged which pinpoints certain enzyme activities as important controlling steps. Here, we develop an approach based on pathway analysis and kinetic modelling to assess the biochemical control of sucrose accumulation and futile cycling in sugar cane. By using the concept of elementary flux modes, all possible routes of futile cycling of sucrose were enumerated in the metabolic system. The available kinetic data for the pathway enzymes were then collected and assembled in a kinetic model of sucrose accumulation in sugar cane culm tissue. Although no data were fitted, the model agreed well with independent experimental results: in no case was the difference between calculated and measured fluxes and concentrations greater than 2-fold. The model thus validated was then used to assess different enhancement strategies for increasing sucrose accumulation. First, the control coefficient of each enzyme in the system on futile cycling of sucrose was calculated. Secondly, the activities of those enzymes with the numerically largest control coefficients were varied over a 5-fold range to determine the effect on the degree of futile cycling, the conversion efficiency from hexoses into sucrose, and the net sucrose accumulation rate. In view of the modelling results, overexpression of the fructose or glucose transporter or the vacuolar sucrose import protein, as well as reduction of cytosolic neutral invertase levels, appear to be the most promising targets for genetic manipulation. This offers a more directed improvement strategy than cumbersome gene-by-gene manipulation. The kinetic model can be viewed and interrogated on the World Wide Web at http://jjj.biochem.sun.ac.za. PMID:11513743

  9. In vivo survival of (14C)sucrose-loaded porcine carrier erythrocytes

    SciTech Connect

    DeLoach, J.R.

    1983-06-01

    Porcine carrier erythrocyte survival was measured in adult pigs. (14C)Sucrose-loaded erythrocytes had a biphasic survival curve, with as much as 50% of the cells removed from circulation in the first 24 hours. The remaining cells had a 35-day half-life. Encapsulation values were measured for porcine erythrocytes and entrapment of (14C)sucrose was greater than 45%. Addition of inosine and glucose to the dialyzed cells and to the final wash buffer before reinjection of autologous cells did not improve their survival.

  10. In vitro and in vivo effects of standardized extract and fractions of Phaleria macrocarpa fruits pericarp on lead carbohydrate digesting enzymes

    PubMed Central

    2013-01-01

    Background One vital therapeutic approach for the treatment of type 2 diabetes mellitus is the use of agents that can decrease postprandial hyperglycaemia by inhibiting carbohydrate digesting enzymes. The present study investigated the effects of bioassay-guided extract and fractions of the dried fruit pericarp of Phaleria macrocarpa, a traditional anti-diabetic plant, on ?-glucosidase and ?-amylase, in a bid to understand their anti-diabetic mechanism, as well as their possible attenuation action on postprandial glucose increase. Methods Methanol extract (ME), obtained by successive solvent extraction, its most effective liquid-liquid n-butanol fraction (NBF) and the flash column chromatographic sub-fraction (SFI), were evaluated for in vitro ?-glucosidase (yeast) and ?-amylase (porcine) activity inhibition. Furthermore, confirmatory in vivo tests were carried out in streptozotocin-induced diabetic rats (SDRs) using oral glucose, sucrose and starch tolerance tests. Results At the highest concentration employed (100 ?g/ml), NBF showed highest inhibition against ?-glucosidase (75%) and ?-amylase (87%) in vitro (IC50?=?2.40?±?0.23 ?g/ml and 58.50?±?0.13 ?g/ml, respectively) in a dose-dependent fashion; an effect found to be about 20% higher than acarbose (55%), a standard ?-glucosidase inhibitor (IC50?=?3.45?±?0.19 ?g/ml). The ME and SFI also inhibited ?-glucosidase (IC50?=?7.50?±?0.15 ?g/ml and 11.45?±?0.28 ?g/ml) and ?-amylase (IC50?=?43.90?±?0.19 ?g/ml and 69.80?±?0.25 ?g/ml), but to a lesser extent. In in vivo studies with diabetic rats, NBF and SFI effectively reduced peak blood glucose (PBG) by 15.08% and 6.46%, and the area under the tolerance curve (AUC) by 14.23% and 12.46%, respectively, after an oral sucrose challenge (P?

  11. Drosophila Regulate Yeast Density and Increase Yeast Community Similarity in a Natural Substrate

    PubMed Central

    Stamps, Judy A.; Yang, Louie H.; Morales, Vanessa M.; Boundy-Mills, Kyria L.

    2012-01-01

    Drosophila melanogaster adults and larvae, but especially larvae, had profound effects on the densities and community structure of yeasts that developed in banana fruits. Pieces of fruit exposed to adult female flies previously fed fly-conditioned bananas developed higher yeast densities than pieces of the same fruits that were not exposed to flies, supporting previous suggestions that adult Drosophila vector yeasts to new substrates. However, larvae alone had dramatic effects on yeast density and species composition. When yeast densities were compared in pieces of the same fruits assigned to different treatments, fruits that developed low yeast densities in the absence of flies developed significantly higher yeast densities when exposed to larvae. Across all of the fruits, larvae regulated yeast densities within narrow limits, as compared to a much wider range of yeast densities that developed in pieces of the same fruits not exposed to flies. Larvae also affected yeast species composition, dramatically reducing species diversity across fruits, reducing variation in yeast communities from one fruit to the next (beta diversity), and encouraging the consistent development of a yeast community composed of three species of yeast (Candida californica, C. zemplinina, and Pichia kluvyeri), all of which were palatable to larvae. Larvae excreted viable cells of these three yeast species in their fecal pools, and discouraged the growth of filamentous fungi, processes which may have contributed to their effects on the yeast communities in banana fruits. These and other findings suggest that D. melanogaster adults and their larval offspring together engage in ‘niche construction’, facilitating a predictable microbial environment in the fruit substrates in which the larvae live and develop. PMID:22860093

  12. Silver Sucrose Octasulfate (IASOS™) as a Valid Active Ingredient into a Novel Vaginal Gel against Human Vaginal Pathogens: In Vitro Antimicrobial Activity Assessment

    PubMed Central

    Marianelli, Cinzia; Petrucci, Paola; Comelli, Maria Cristina; Calderini, Gabriella

    2014-01-01

    This in vitro study assessed the antimicrobial properties of a novel octasilver salt of Sucrose Octasulfate (IASOS) as well as of an innovative vaginal gel containing IASOS (SilSOS Femme), against bacterial and yeast pathogens isolated from human clinical cases of symptomatic vaginal infections. In BHI and LAPT culture media, different ionic silver concentrations and different pHs were tested. IASOS exerted a strong antimicrobial activity towards all the pathogens tested in both culture media. The results demonstrated that salts and organic compounds present in the culture media influenced IASOS efficacy only to a moderate extent. Whereas comparable MBCs (Minimal Bactericidal Concentrations) were observed for G. vaginalis (10 mg/L Ag+), E. coli and E. aerogenes (25 mg/L Ag+) in both media, higher MBCs were found for S. aureus and S. agalactiae in LAPT cultures (50 mg/L Ag+ versus 25 mg/L Ag+). No minimal concentration totally inhibiting the growth of C. albicans was found. Nevertheless, in both media at the highest ionic silver concentrations (50–200 mg/L Ag+), a significant 34–52% drop in Candida growth was observed. pH differently affected the antimicrobial properties of IASOS against bacteria or yeasts; however, a stronger antimicrobial activity at pH higher than the physiological pH was generally observed. It can be therefore concluded that IASOS exerts a bactericidal action against all the tested bacteria and a clear fungistatic action against C. albicans. The antimicrobial activity of the whole vaginal gel SilSOS Femme further confirmed the antimicrobial activity of IASOS. Overall, our findings support IASOS as a valid active ingredient into a vaginal gel. PMID:24897299

  13. Induction when Rats Respond for Liquid-Sucrose Reinforcement as a Function of Amount of Upcoming "Work"

    ERIC Educational Resources Information Center

    Weatherly, Jeffrey N.; Bauste, Grant A.; McDougall, Casey L.; Nurnberger, Jeri T.

    2006-01-01

    Previous research has shown that rats increase their rate of responding for 1% sucrose reinforcement in the first half of the session if food-pellet, rather than 1% sucrose, reinforcement will be available in the second half (i.e., positive induction). Four experiments investigated whether this induction effect would be changed by altering the…

  14. Deprivation of both sucrose and water reduces the mosquito heart contraction rate while increasing the expression of nitric oxide synthase.

    PubMed

    Ellison, Haley E; Estévez-Lao, Tania Y; Murphree, C Steven; Hillyer, Julián F

    2015-03-01

    Adult female mosquitoes rely on carbohydrate-rich plant nectars as their main source of energy. In the present study we tested whether the deprivation of a carbohydrate dietary source or the deprivation of both carbohydrate and water affects mosquito heart physiology. Intravital video imaging of Anopheles gambiae showed that, relative to sucrose fed mosquitoes, the deprivation of both sucrose and water for 24h, but not the deprivation of sucrose alone, reduces the heart contraction rate. Measurement of the protein, carbohydrate and lipid content of mosquitoes in the three treatment groups did not explain this cardiac phenotype. However, while the deprivation of sucrose reduced mosquito weight and abdominal width, the deprivation of both sucrose and water reduced mosquito weight even further without augmenting the change in abdominal width, indirectly suggesting that starvation and dehydration reduces hemolymph pressure. Analysis of the mRNA levels of crustacean cardioactive peptide (CCAP), FMRFamide, corazonin, neuropeptide F and short neuropeptide F then suggested that these neuropeptides do not regulate the cardiac phenotype observed. However, relative to sucrose fed and sucrose deprived mosquitoes, the mRNA level of nitric oxide synthase (NOS) was significantly elevated in mosquitoes that had been deprived of both sucrose and water. Given that nitric oxide suppresses the heart rate of vertebrates and invertebrates, these data suggest a role for this free radical in modulating mosquito heart physiology. PMID:25640058

  15. The rooting performance of shea (Vitellaria paradoxa gaertn) stem cuttings as influenced by wood type, sucrose and rooting hormone

    Microsoft Academic Search

    J. Yeboah; S. T. Lowor; F. M. Amoah

    2009-01-01

    Vegetative propagation of stem cuttings of different physiological woodtypes of Vitellaria paradoxa was studied in a polythene propagator. The treatments included combinations of wood type (soft, semi-hard and rejuvenated (coppiced) shoots), sucrose application at 0, 15 and 25%, and Seradix '3' powder hor- mone (active ingredient- indolebutyricacid) at 0 and 8000 ppm. Cuttings of rejuvenated shoots dipped in 15% sucrose

  16. Lesions of the medial prefrontal cortex enhance the early phase of psychogenic fever to unexpected sucrose concentration reductions, promote recovery from negative contrast and enhance spontaneous recovery of sucrose-entrained anticipatory activity.

    PubMed

    Pecoraro, N; de Jong, H; Ginsberg, A B; Dallman, M F

    2008-06-01

    Two groups of rats, one bearing bilateral excitotoxic lesions of the medial prefrontal cortex (mPFC) and one sham-lesioned group, were run in a successive negative contrast paradigm. Both groups had telemeters implanted to monitor core temperature and activity. After ad libitum baseline and food restriction to 85% body weights, rats received a sucrose solution once daily for 5 min and 30 s at 10:30 h. They received their preshift 32% sucrose solution for 14 days followed by a sucrose concentration reduction (downshift) to 4% sucrose for 12 days. Rats were then upshifted to 32% for six additional days before being downshifted to 4% for the next 6 days. There were no differences in intake of the 32% sucrose during the preshift. All rats showed profound suppression of intake upon the shift to 4% sucrose. On the first day of the unexpected 4% sucrose, lesioned rats showed an enhanced psychogenic fever compared with Shams, whereas on the second day of 4% sucrose they showed an impaired ability to blunt that fever compared with Shams. In addition, lesioned rats showed greater rates of recovery and asymptotic drinking of the subsequent 4% sucrose solution than Shams, indicating impairments in the encoding or retrieval of the shift. In addition, lesioned rats showed enhanced entrainment to the 32% sucrose meals, normal damping of anticipation, and enhanced spontaneous recovery of anticipatory thermal responses to the calorically impoverished 4% solutions. These failures to inhibit responding point to a failure in interference learning in rats bearing lesions of the mPFC. PMID:18455879

  17. In vitro antimicrobial activity of ethanol and water extracts of Cassia alata

    Microsoft Academic Search

    M. N Somchit; I Reezal; I. Elysha Nur; A. R Mutalib

    2003-01-01

    Crude ethanol and water extract of leaves and barks from Cassia alata were tested in vitro against fungi, (Aspergillus fumigatus and Microsporum canis), yeast (Candida albicans) and bacteria (Staphylococcus aereus and Escherichia coli). C. albicans showed concentration-dependent susceptibility towards both the ethanol and water extracts from the barks, but resistant towards the extracts of leaves. The degree of susceptibility varied,

  18. Prevention of Yeast Spoilage in Feed and Food by the Yeast Mycocin HMK

    PubMed Central

    Lowes, K. F.; Shearman, C. A.; Payne, J.; MacKenzie, D.; Archer, D. B.; Merry, R. J.; Gasson, M. J.

    2000-01-01

    The yeast Williopsis mrakii produces a mycocin or yeast killer toxin designated HMK; this toxin exhibits high thermal stability, high pH stability, and a broad spectrum of activity against other yeasts. We describe construction of a synthetic gene for mycocin HMK and heterologous expression of this toxin in Aspergillus niger. Mycocin HMK was fused to a glucoamylase protein carrier, which resulted in secretion of biologically active mycocin into the culture media. A partial purification protocol was developed, and a comparison with native W. mrakii mycocin showed that the heterologously expressed mycocin had similar physiological properties and an almost identical spectrum of biological activity against a number of yeasts isolated from silage and yoghurt. Two food and feed production systems prone to yeast spoilage were used as models to assess the ability of mycocin HMK to act as a biocontrol agent. The onset of aerobic spoilage in mature maize silage was delayed by application of A. niger mycocin HMK on opening because the toxin inhibited growth of the indigenous spoilage yeasts. This helped maintain both higher lactic acid levels and a lower pH. In yoghurt spiked with dairy spoilage yeasts, A. niger mycocin HMK was active at all of the storage temperatures tested at which yeast growth occurred, and there was no resurgence of resistant yeasts. The higher the yeast growth rate, the more effective the killing action of the mycocin. Thus, mycocin HMK has potential applications in controlling both silage spoilage and yoghurt spoilage caused by yeasts. PMID:10698773

  19. Anhydrobiosis in yeast: influence of calcium and magnesium ions on yeast resistance to dehydration-rehydration.

    PubMed

    Trofimova, Yuliya; Walker, Graeme; Rapoport, Alexander

    2010-07-01

    The influence of calcium and magnesium ions on resistance to dehydration in the yeast, Saccharomyces cerevisiae, was investigated. Magnesium ion availability directly influenced yeast cells' resistance to dehydration and, when additionally supplemented with calcium ions, this provided further significant increase of yeast resistance to dehydration. Gradual rehydration of dry yeast cells in water vapour indicated that both magnesium and calcium may be important for the stabilization of yeast cell membranes. In particular, calcium ions were shown for the first time to increase the resistance of yeast cells to dehydration in stress-sensitive cultures from exponential growth phases. It is concluded that magnesium and calcium ion supplementations in nutrient media may increase the dehydration stress tolerance of S. cerevisiae cells significantly, and this finding is important for the production of active dry yeast preparations for food and fermentation industries. PMID:20487021

  20. Yeast Breads: Made at Home. 

    E-print Network

    Reasonover, Frances

    1971-01-01

    and salt. Cool to lukewarm. Add softened yeast. Blend well. Gradually add flour to form a soft dough. Cover. Let rise in warm place until light and doubled in bulk from 1% to 2 hours. Roll out dough on well-floured surface or pastry cloth to a 15... Turn dough onto surface well dusted with . Knead until smooth, about 20 times. :sired, into crescents, rolls, etc. Place on jed baking sheet. Cover with damp cloth. warm place, free from draft, about 1 hour. F. 10 to 15 minutes, depending on size...