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Extraction of sucrose from molasses  

SciTech Connect

Sucrose is extracted from molasses by passing an aqueous molasses solution over an adsorbent, e.g., calcined Al/sub 2/O/sub 3/-supported pyrolyzed C/sub 6/H/sub 6/. Thus, 10 mL molasses (approximately 46% solids) was run through a column containing 70 cubic centimetres above adsorbent with sucrose retention volume 21.4 and selectivity for sucrose - betaine 23.8.

Landis, A.M.



Stimulation of lactobacilli during alcoholic fermentation: action of sucrose hydrolysis by yeast  

Microsoft Academic Search

Summary Behaviour of lactic acid bacteria especially their stimulation in mixed culture with yeast was studied. In alcoholic fermentation of molasses worts, bacterial growth was stimulated as the yeast inoculum size increase. The consumption of monosaccharides (glucose and fructose) liberated during hydrolysis of sucrose by yeast is proposed as a major factor accounting for this phenomenon.

J. J. Essia Ngang; E. Wolniewicz; F. Letourneau; P. Villa



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

E-print Network

of these sugars causes repression of gluconeogenesis, the glyoxylate cycle, respiration and the uptake of less the activation of cellular growth, the mobilization of storage compounds and the diminution of cellular stress in gluconeo- genesis and respiration. The repression of respiration by glucose and sucrose, which is known


Continuous alcoholic fermentation of sucrose using flocculating yeast. The limits of invertase activity  

Microsoft Academic Search

Summary At high flow rates, the continuous alcoholic fermentation of sucrose in a laboratory fermenter with internal cell recycle, using a strongly flocculating yeast can be limited by the substrate hydrolysis. This system is sensitive to glucose catabolic repression and to mineral deficiency. The release of invertase activity in the medium is negligible. From theoretical and experimental considerations, the hydrolysis

A. Fontana; C. Ghommidh; J. P. Guiraud; J. M. Navarro



Preparation of extracts from yeast.  


Because yeast is exceptionally well suited to genetic analysis, both classical and molecular, it is an attractive system for expressing recombinant animal proteins for purification purposes. Methods available for lysing yeast cells include autolysis, pressure cells (e.g., French press), abrasives (glass bead vortexing), and enzymatic lysis (e.g., zymolase). One of the simplest methods, discussed in this protocol, involves the abrasive action of well-agitated glass beads. This is a very effective method for both low volumes (e.g., <1 mL using a microcentrifuge tube) and many liters using a specialized DynoMill apparatus. Cell breakage is typically >95%, as assessed by phase-contrast microscopy. PMID:21205845

Simpson, Richard J



21 CFR 172.590 - Yeast-malt sprout extract.  

... 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...



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


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

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



The effect of pH, sodium chloride, sucrose, sorbate and benzoate on the growth of food spoilage yeasts  

Microsoft Academic Search

The effects of pH, concentration of NaCl, concentration of sucrose and concentrations of sorbic and benzoic acids on growth were examined for 30 strains of food spoilage yeasts, representingDebaryomyces hansenii, Yarrowia lipolytica, Kloeckera apiculata, Zygosaccharomyces bailii, Zygosaccharomyces rouxii, Kluyveromyces marxianus, Pichia membranaefaciens, Pichia anomalaandSaccharomyces cerevisiae.Zygosaccharomyces bailiidid not grow at pH 7.0 andZ. rouxii, Kl. apiculataandP. membranaefaciensdid not grow at pH

W Praphailong; G. H Fleet



In situ biphasic extractive fermentation for hexanoic acid production from sucrose by Megasphaera elsdenii NCIMB 702410.  


Hexanoic acid production by a bacterium using sucrose as an economic carbon source was studied under conditions in which hexanoic acid was continuously extracted by liquid-liquid extraction. Megasphaera elsdenii NCIMB 702410, selected from five M. elsdenii strains, produced 4.69 g l?¹ hexanoic acid in a basal medium containing sucrose. Production increased to 8.19 g l?¹ when the medium was supplemented by 5 g l?¹ sodium butyrate. A biphasic liquid-liquid extraction system with 10 % (v/v) alamine 336 in oleyl alcohol as a solvent was evaluated in a continuous stirred-tank reactor held at pH 6. Over 90 % (w/w) of the hexanoic acid in a 0.5 M aqueous solution was transferred to the extraction solvent within 10 h. Cell growth was not significantly inhibited by direct contact of the fermentation broth with the extraction solvent. The system produced 28.42 g l?¹ of hexanoic acid from 54.85 g l?¹ of sucrose during 144 h of culture, and 26.52 and 1.90 g l?¹ of hexanoic acid was accumulated in the extraction solvent and the aqueous fermentation broth, respectively. The productivity and yield of hexanoic acid were 0.20 g l?¹ h?¹ and 0.50 g g?¹ sucrose, respectively. PMID:23754557

Choi, Kieun; Jeon, Byoung Seung; Kim, Byung-Chun; Oh, Min-Kyu; Um, Youngsoon; Sang, Byoung-In



Charcoal-Yeast Extract Agar: Primary Isolation Mediumfor Legionella pneumophila  

Microsoft Academic Search

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




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


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

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



The influence of exogenous nutrients on the abundance of yeasts on the phylloplane of turfgrass.  


Four experiments were conducted to assess the effect of foliar applications of various nutrient solutions on the phylloplane yeast community of tall fescue (Festuca arundinacea Schreb.). In the first three experiments, increasing concentrations of sucrose (2-16%), yeast extract (0.5-2.5%), and sucrose plus yeast extract (2.5-18.5% total) were applied and the yeast colony forming units (cfu) enumerated 14 h later by dilution plating. Significant positive linear relationships were observed between the number of yeast cfu and applications of both yeast extract and sucrose plus yeast extract. Foliar applications of sucrose alone had no significant effect on yeast community abundance, indicating that phylloplane yeasts of turfgrass are not limited by the amount or availability of carbohydrates. In the fourth experiment, five different solutions were applied to tall fescue to investigate the response of the yeast community to organic and inorganic nitrogen sources. Tryptone or yeast extract, both with considerable amino acid composition, significantly increased the yeast population, while yeast nitrogen base (with or without amino acids) and ammonium sulfate had no affect on yeast abundance. These results suggest that organic nitrogen stimulate yeast community growth and development on the phylloplane of tall fescue, while carbohydrates, inorganic nitrogen, and non-nitrogenous nutrients have little positive effect. PMID:17487523

Nix-Stohr, Shannon; Burpee, Leon L; Buck, James W



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


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

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



A rapid and simple method for extracting yeast mitochondrial DNA  

Microsoft Academic Search

A rapid method for the extraction of yeast mitochondrial DNA (mtDNA) is described. In comparison with previous methods, it simplifies several steps, does not require either the isolation of mitochondria or phenol treatment and is less time consuming. This protocol gives a high yield of pure mtDNA (50–120 µg from a 100-ml culture), which can be directly used in various

Ali Gargouri; M. Curie



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

PubMed Central

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

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



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


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

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



Autolysis of the red yeast Phaffia rhodozyma: A potential tool to facilitate extraction of astaxanthin  

Microsoft Academic Search

Distilled water and 0.02 molar citrate buffer pH 7.0, are suitable autolysing systems for the red yeast P. rhodozyma. Autolysis renders astaxanthin extractable from the yeast. Of six strains of the yeast tested, 67–484 was most susceptible to autolysis.

R. N. Okagbue; M. J. Lewis



Occurrence and Growth of Yeasts in Yogurts  

PubMed Central

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

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



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


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

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



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

PubMed Central

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

Petelinc, Tanja; Polak, Tomaz; Demsar, Lea; Jamnik, Polona



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


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

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



Effect of yeast extract on Escherichia coli growth and acetic acid production  

Microsoft Academic Search

Fed batch cultures were performed to investigate the effect of yeast extract concentration on the kinetics of growth and acetic acid production of recombinant Escherichia coli BL21 in a synthetic medium. Three runs were performed with 40g\\/l total glucose concentration. The yeast extract\\/glucose ratio (YE\\/G; w\\/w), was 0.1, 0.05 and 0.025 in the feed. These decreasing YE\\/G values did not

D. C. Suárez; C. W. Liria; B. V. Kilikian



Molecular Structure of Sucrose  

NSDL National Science Digital Library

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.



Selection of yeasts for single cell protein production on media based on Jerusalem artichoke extracts.  


Several yeast strains can grow with good yield (0.16 to 0.19 mg protein/mg carbohydrate) on nitrogen supplemented Jerusalem artichoke extract. The most promising strain is Lipomyces starkeyi. Including by-products (pulps, proteins of extract), protein production can reach 2 metric tons/ha. PMID:6613165

Apaire, V; Guiraud, J P; Galzy, P



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

Microsoft Academic Search

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

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



Separation of astaxanthin from red yeast Phaffia rhodozyma by supercritical carbon dioxide extraction  

Microsoft Academic Search

The supercritical fluid extraction (SFE) behavior was investigated to extract astaxanthin from the red yeast Phaffia rhodozyma, which was disrupted and dried by bead mill and spray dryer, respectively. The effects of extraction pressure (102–500bar), temperature (40, 60 and 80°C), CO2 flow rate (superficial velocities of 0.27 and 0.54cm\\/min) and the use of ethyl alcohol as a modifier (1, 5,

Gio-Bin Lim; Sang-Yun Lee; Eun-Kyu Lee; Seung-Joo Haam; Woo-Sik Kim



Continuous ethanol production by immobilized yeast cells and ethanol recovery by liquid-liquid extraction  

SciTech Connect

Contributions on ethanol fermentation by immobilized yeast cells and ethanol-water separation by liquid-liquid extraction are presented. The characterization of a packed-bed fermentor with yeast immobilized in carrageenan gel beads as well as its main operational features are reported, giving special emphasis to cell growth inside the beads during continuous fermentation experiments. A new separation process for dilute ethanol-water mixtures based on a solvent extraction step is proposed. The process development and solvent selection have been carried out. Although the first results are promising, the energy costs of the process are still too high.

Sola, C.; Casas, C.; Godia, F.; Poch, M.; Serra, A.; Scott, C.D. (ed.)



The inhibitory effects of mushroom extracts on sucrose-dependent oral biofilm formation  

Microsoft Academic Search

Mushrooms contain large quantities of ?-glucans. Shiitake (Lentinula edodes), Japan’s most popular edible mushroom, has been reported to contain about 6% (weight\\/dried weight) of ?-(1,3)-glucan. This\\u000a glucan is one of the major components of oral biofilm formed by the cariogenic bacteria Streptococcus mutans and Streptococcus sobrinus. We found that extracts from shiitake and other edible mushrooms could reduce preformed biofilms

Akira Yano; Sayaka Kikuchi; Yoshihisa Yamashita; Yuichi Sakamoto; Yuko Nakagawa; Yasuo Yoshida



Biphenyl synthase from yeast-extract-treated cell cultures of Sorbus aucuparia  

Microsoft Academic Search

Biphenyls and dibenzofurans are the phytoalexins of the Maloideae, a subfamily of the economically important Rosaceae. The biphenyl aucuparin accumulated in Sorbus aucuparia L. cell cultures in response to yeast extract treatment. Incubation of cell-free extracts from challenged cell cultures with benzoyl-CoA and malonyl-CoA led to the formation of 3,5-dihydroxybiphenyl. This reaction was catalysed by a novel polyketide synthase, which

Benye Liu; Till Beuerle; Tim Klundt; Ludger Beerhues



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


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

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



Sequential extraction leading to improved proteomic analysis of the oleaginous yeast Lipomyces starkeyi.  


The oleaginous yeast Lipomyces starkeyi (L. starkeyi) is an excellent intracellular lipid producer. Thus, extraction of protein from lipid-rich L. starkeyi samples following conventional methods can be difficult, leading to poor data in terms of proteomic analysis. The presence of lipophilic components in those samples may also interfere with the extraction process and the downstream analysis. In this work, we developed a sequential extraction method for preparation and analysis of L. starkeyi proteome combining to an online multidimensional nano reversed-phase liquid chromatography-tandem mass spectrometry (microRPLC-MS/MS) strategy. Protein hits of high confidence reached 227 with false positive rate less than 0.1, twice of those identified from the one-buffer extraction preparation. Moreover, the protein hits related to primary metabolism was increased, which may be important to establish the molecular mechanism of lipid accumulation. The method should be valuable for protein extraction from oleaginous species. PMID:21847969

Liu, Hongwei; Zhao, Xin; Cheng, Kai; Zhao, Zongbao; Ye, Mingliang



Aniline blue-containing buffered charcoal-yeast extract medium for presumptive identification of Legionella species  

SciTech Connect

By utilizing buffered charcoal-yeast extract medium containing 0.01% aniline blue in conjunction with a long-wave UV light, the differentiation of five species of Legionella was facilitated. L. pneumophila, when grown on this medium, did not absorb the aniline blue dye; however, L. micdadei, L. dumoffii, L. bozemanii, and L. gormanii absorbed the dye in varying amounts and produced colonies of various shades of blue.

Holmes, R.L.



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

Microsoft Academic Search

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

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



Effects of yeast extract and glucose on xanthan production and cell growth in batch culture of Xanthomonas campestris  

Microsoft Academic Search

Although available kinetic data provide a useful insight into the effects of medium composition on xanthan production by\\u000a Xanthomonas campestris, they cannot account for the synergetic effects of carbon (glucose) and nitrogen (yeast extract) substrates on cell growth\\u000a and xanthan production. In this work, we studied the effects of the glucose\\/yeast-extract ratio (G\\/YE) in the medium on cell\\u000a growth and

Yang-Ming Lo; Shang-Tian Yang; David B. Min



Utilization capability of sucrose, raffinose and inulin and its less-sensitiveness to glucose repression in thermotolerant yeast Kluyveromyces marxianus DMKU 3-1042  

PubMed Central

Kluyveromyces marxianus possesses a useful potential to assimilate a wide variety of substrates at a high temperature, but the negative effect by coexisting glucose is critical for utilization of biomass containing various sugars. Such a negative effect on the activity of inulinase, which is the sole enzyme to hydrolyze sucrose, raffinose and inulin, has been demonstrated in K. marxianus without analysis at the gene level. To clarify the utilization capability of sucrose, raffinose and inulin and the glucose effect on inulinase in K. marxianus DMKU 3-1042, its growth and metabolite profiles on these sugars were examined with or without glucose under a static condition, in which glucose repression evidently occurs. Consumption of sucrose was not influenced by glucose or 2-deoxyglucose. On the other hand, raffinose and inulin consumption was hampered by glucose at 30°C but hardly hampered at 45°C. Unlike Saccharomyces cerevisiae, increase in glucose concentration had no effect on sucrose utilization. These sugar-specific glucose effects were consistent with the level of inulinase activity but not with that of the KmINU1 transcript, which was repressed in the presence of glucose via KmMig1p. This inconsistency may be due to sufficient activity of inulinase even when glucose is present. Our results encourage us to apply K. marxianus DMKU 3-1042 to high-temperature ethanol fermentation with biomass containing these sugars with glucose. PMID:21920047



Norovirus capsid protein expressed in yeast forms virus-like particles and stimulates systemic and mucosal immunity in mice following an oral administration of raw yeast extracts.  


Norovirus (NV) gastroenteritis is a widespread disease affecting people of all ages worldwide. A simple, safe, and easily deliverable vaccine may be the key for the control and prevention of NV gastroenteritis. In this study, we demonstrated that a NV recombinant capsid protein (strain VA387, genogroup II.4) expressed in yeast (Pichia pastoris) spontaneously formed virus-like particles (VLPs) like those expressed in other in vitro systems. Oral administration of raw material from the yeast cell lysates containing 0.1 mg of VLPs without an adjuvant resulted in systemic and mucosal immune responses in mice. Significantly higher and earlier responses were observed in mice receiving a higher dose (1 mg per dose) of the antigen. Both the serum and fecal antibodies blocked VA387 VLP binding to its histo-blood group antigen receptors. The animals did not reveal any side effect following the administration of the yeast lysates. Our results indicated that yeast is a simple, effective alternative for NV VLP production. The mice immunization study also indicated that the oral administration of raw yeast extracts without an adjuvant is a safe and simple way which is worth to be studied for vaccine delivery in humans. PMID:17133551

Xia, Ming; Farkas, Tibor; Jiang, Xi



Biphenyl synthase from yeast-extract-treated cell cultures of Sorbus aucuparia.  


Biphenyls and dibenzofurans are the phytoalexins of the Maloideae, a subfamily of the economically important Rosaceae. The biphenyl aucuparin accumulated in Sorbus aucuparia L. cell cultures in response to yeast extract treatment. Incubation of cell-free extracts from challenged cell cultures with benzoyl-CoA and malonyl-CoA led to the formation of 3,5-dihydroxybiphenyl. This reaction was catalysed by a novel polyketide synthase, which will be named biphenyl synthase. The most efficient starter substrate for the enzyme was benzoyl-CoA. Relatively high activity was also observed with 2-hydroxybenzoyl-CoA but, instead of the corresponding biphenyl, the derailment product 2-hydroxybenzoyltriacetic acid lactone was formed. PMID:14595561

Liu, Benye; Beuerle, Till; Klundt, Tim; Beerhues, Ludger



Recovery of spores of Clostridium botulinum in yeast extract agar and pork infusion agar after heat treatment.  

PubMed Central

Yeast extract agar, pork infusion agar, and modifications of these media were used to recover heated Clostridium botulinum spores. The D- and z-values were determined. Two type A strains and one type B strain of C. botulinum were studied. In all cases the D-values were largest when the spores were recovered in yeast extract agar, compared to the D-values for spores recovered in pork infusion agar. The z-values for strains 62A and A16037 were largest when the spores were recovered in pork infusion agar. The addition of sodium bicarbonate and sodium thioglycolate to pork infusion agar resulted in D-values for C. botulinum 62A spores similar to those for the same spores recovered in yeast extract agar. The results suggest that sodium bicarbonate and sodium thioglycolate should be added to recovery media for heated C. botulinum spores to obtain maximum plate counts. PMID:335970

Odlaug, T E; Pflug, I J



Isomaltulose production from sucrose by Protaminobacter rubrum immobilized in calcium alginate.  


Different culture conditions for Protaminobacter rubrum and enzymatic reaction parameters were evaluated with the goal of improving isomaltulose production. P. rubrum was grown in a medium with 1% (w/v) cane molasses and 0.5% yeast extract and achieved a maximum cell yield Y(x/s) of 0.295 g of cells/g sucrose and a specific growth rate (mu) of 0.192 h(-1). The immobilization of P. rubrum cells was carried out with calcium alginate, glutaraldehyde and polyethyleneimine. Stabile immobilized cell pellets were obtained and used 24 times in batch processes. Enzymatic conversion was carried out at different sucrose concentrations and in pH 6 medium with 70% (w/v) sucrose at 30 degrees C an isomaltulose yield of 89-94% (w/v) was obtained. The specific activity of the P. rubrum immobilized pellets in calcium alginate at 30 degrees C ranged from 1.6 to 4.0 g isomaltulose g(-1) pellet h(-1), respectively with 70% and 65% sucrose solution, while in lower sucrose concentration had higher specific activities presumably due to substrate inhibition of the isomaltulose synthase in higher sucrose concentrations. PMID:19410450

de Oliva-Neto, P; Menão, Paula T P



Chemistry and genotoxicity of caramelized sucrose.  


Caramelization of a 1% sucrose solution at 180 degrees C accompanied characteristic changes in pH, Mr, UV-absorbance, and fluorescence values as well as increased reducing power activity after 40-60 min. Similar changes occurred to sucrose heated at 150 degrees C, after 150-240 min. Bioactivity of caramelized sucrose samples was tested for mutagenic activity, using Salmonella typhimurium strains TA-98 and TA-100, respectively, as well as the Saccharomyces D7 yeast strain for mitotic recombination and Chinese hamster ovary cells (CHO) to assess clastogenicity. Caramelized sucrose expressed no mutagenicity in the TA-98 strain, but gave positive (p < 0.05) results with the TA-100, base-pair substitution strain. Similarly, mitotic recombination in the Saccharomyces D7 yeast strain and clastogenic activity in CHO cells were induced when exposed to caramelized sucrose. In the all cases, preincubation with S-9 reduced (p < 0.05) the mutagenic activities of caramelized sucrose. Fractionation of the caramelized sucrose into volatile and nonvolatile compounds was performed and tested for clastogenicity using CHO cells. Volatile components contributed approximately 10% to total clastogenicity, which was enhanced by the presence of S-9. Nonvolatile components recovered, consisting of relatively lower Mr, gave highest (p < 0.05) clastogenic activity, denoting that higher Mr caramel colors are relatively free of this property. PMID:17103379

Kitts, David D; Wu, C H; Kopec, A; Nagasawa, T



The effect of yeast extract supplementation on the production of lactic acid from whey permeate by Lactobacillus helueticus  

Microsoft Academic Search

Batch and continuous two-stage cultures have been conducted in order to determine the effect of yeast extract (YE) on the homolactic fermentation of whey permeate byLactobacillus helveticus. Supplementation with YE had a significant effet on lactic acid concentration, volumetric productivity, and substrate conversion, but not on lactic acid yield. Volumetric productivity in the first stage increased from 2 to 9

A. Aeschlimann; U. von Stockar



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

PubMed Central

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

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



Extraction of nucleic acids from yeast cells and plant tissues using ethanol as medium for sample preservation and cell disruption.  


Here we report that dehydrated ethanol is an excellent medium for both in situ preservation of nucleic acids and cell disruption of plant and yeast cells. Cell disruption was strongly facilitated by prior dehydration of the ethanol using dehydrated zeolite. Following removal of ethanol, nucleic acids were extracted from the homogenate pellet using denaturing buffers. The method provided DNA and RNA of high yield and integrity. Whereas cell wall disruption was essential for extraction of DNA and large RNA molecules, smaller molecules such as tRNAs could be selectively extracted from undisrupted, ethanol-treated yeast cells. Our results demonstrate the utility of absolute ethanol for sample fixation, cell membrane and cell wall disruption, as well as preservation of nucleic acids during sample storage. PMID:20854267

Linke, Bettina; Schröder, Kersten; Arter, Juliane; Gasperazzo, Tatiana; Woehlecke, Holger; Ehwald, Rudolf



Coupled RNA polymerase II transcription and 3? end formation with yeast whole-cell extracts  

PubMed Central

RNA polymerase II (RNAP II) transcription and pre-mRNA 3? end formation are linked through physical and functional interactions. We describe here a highly efficient yeast in vitro system that reproduces both transcription and 3? end formation in a single reaction. The system is based on simple whole-cell extracts that were supplemented with a hybrid Gal4-VP16 transcriptional activator and supercoiled plasmid DNA templates encoding G-less cassette reporters. We found that the coupling of transcription and processing in vitro enhanced pre-mRNA 3? end formation and reproduced requirements for poly(A) signals and polyadenylation factors. Unexpectedly, however, we show that in vitro transcripts lacked m7G-caps. Reconstitution experiments with CF IA factor assembled entirely from heterologous components suggested that the CTD interaction domain of the Pcf11 subunit was required for proper RNAP II termination but not 3? end formation. Moreover, we observed reduced termination activity associated with extracts prepared from cells carrying a mutation in the 5?-3? exonuclease Rat1 or following chemical inhibition of exonuclease activity. Thus, in vitro transcription coupled to pre-mRNA processing recapitulates hallmarks of poly(A)-dependent RNAP II termination. The in vitro transcription/processing system presented here should provide a useful tool to further define the role of factors involved in coupling. PMID:20810619

Mariconti, Luisa; Loll, Bernhard; Schlinkmann, Karola; Wengi, Agnieszka; Meinhart, Anton; Dichtl, Bernhard



Coupled RNA polymerase II transcription and 3' end formation with yeast whole-cell extracts.  


RNA polymerase II (RNAP II) transcription and pre-mRNA 3' end formation are linked through physical and functional interactions. We describe here a highly efficient yeast in vitro system that reproduces both transcription and 3' end formation in a single reaction. The system is based on simple whole-cell extracts that were supplemented with a hybrid Gal4-VP16 transcriptional activator and supercoiled plasmid DNA templates encoding G-less cassette reporters. We found that the coupling of transcription and processing in vitro enhanced pre-mRNA 3' end formation and reproduced requirements for poly(A) signals and polyadenylation factors. Unexpectedly, however, we show that in vitro transcripts lacked m?G-caps. Reconstitution experiments with CF IA factor assembled entirely from heterologous components suggested that the CTD interaction domain of the Pcf11 subunit was required for proper RNAP II termination but not 3' end formation. Moreover, we observed reduced termination activity associated with extracts prepared from cells carrying a mutation in the 5'-3' exonuclease Rat1 or following chemical inhibition of exonuclease activity. Thus, in vitro transcription coupled to pre-mRNA processing recapitulates hallmarks of poly(A)-dependent RNAP II termination. The in vitro transcription/processing system presented here should provide a useful tool to further define the role of factors involved in coupling. PMID:20810619

Mariconti, Luisa; Loll, Bernhard; Schlinkmann, Karola; Wengi, Agnieszka; Meinhart, Anton; Dichtl, Bernhard



[Mechanism exploration on synthesis of secondary metabolites in Sorbus aucuparia cell cultures treated with yeast extract].  


Suspension cultures cell of Sorbus aucuparia (SASC) was used as materials, the changes of physiological and biochemical indexes of SASC after treatment with yeast extract (YE) were detected, and the synthetic mechanism of secondary metabolites in SASC treated with YE was preliminarily explored. The results were as follows: under the assay conditions, SASC was induced to synthesize five biphenyl compounds, and these compounds content changed differently with induction time prolonging; YE treatment inhibited cell growth, the culture medium pH was gradually reduced after treatment; water-soluble protein content showed a trend of slow decline, which was significantly increased in YE treatment group (YE group) compared with the control group (CK group), the maximum relative content was 147.76% in contrast with CK group; both YE group and CK group were extracellular Ca2+ flow influx, but the YE group flow was significantly slow than CK group. The results indicate that YE induced the cells in a stress state, which was not conducive to the growth of cells and forced the cells to synthesize biphenyl compounds against external stress; water-soluble protein may serve as intracellular enzymes involved in the synthesis of compounds regulation; Ca2+ may as signal molecule mediate cell signal transduction respond to YE stress. PMID:25272834

Huang, Lei; Xiao, Wen-Juan; Yang, Guang; Mo, Ge; Lin, Shu-Fang; Wu, Zhi-Gang; Guo, Lan-Ping



Antiatherosclerotic efficacy of policosanol, red yeast rice extract and astaxanthin in the rabbit.  


The effects of policosanol (P), of extract of red yeast rice (rice fermented with Monascus purpureus) (RYE) and of astaxanthin (A) (constituents of Armolipid) were investigated in a model of experimental atherosclerosis provoked in the rabbit by atherogenic cholesterol-enriched feed (ACEF). P and RYE and their combination were able to lower the increase of serum total cholesterol and of LDL cholesterol elicited by 3-month feeding with ACEF. They also were able to reduce the increase of blood malondialdehyde (MDA), a tracer of lipid peroxidation by the free radicals released by ACEF. When combined, the substances developed either additive or potentiated effects, supporting the rationale of their combination. Remarkable was the protective effect on lipid infiltration in the aortic wall provoked by ACEF, which was reduced by P and by RYE and almost completely prevented by the addition of A to the P-RYE combination. The results support the rationale of a combination of P, RYE and A as a useful food supplement in hyperlipemic patients. PMID:16032970

Setnikar, Ivo; Senin, Paolo; Rovati, Lucio C



Evaluation of the yeast-extract signaling pathway leading to silymarin biosynthesis in milk thistle hairy root culture  

Microsoft Academic Search

The biosynthesis of silymarin, a potent antihepatotoxic compound, from the dried fruits of Silybum marianum L. Gaertn in hairy root cultures can be stimulated by a yeast extract elicitor. These results correlated with culture time,\\u000a and the biosynthesis reached a maximum of 0.47 mg g?1 DW by 72 h after culture (2-fold higher than the control). Lipoxygenase activity and linoleic acid content were

Tahereh Hasanloo; Roshanak Sepehrifar; Hassan Rahnama; Mohammad Reza Shams



Cell-recycle continuous fermentation of Enterococcus faecalis RKY1 for economical production of lactic acid by reduction of yeast extract supplementation.  


Both lactic acid productivity and cell growth were linearly correlated with yeast extract supplementation in batch fermentation. During conventional continuous operation, although fresh feed was introduced into the bioreactor with a significantly low dilution rate (0.04 h(-1)), the amount of yeast extract employed was not enough to maintain the growth of microorganism. However, when the fresh feed contained 100 g/l glucose and 2 g/l yeast extract during cell-recycle continuous operation at a dilution rate of 0.04 h(-1), more than 90 g/l lactic acid was continuously produced, with the average productivity of 3.72 g/l·h. In this experiment, 82 g of yeast extract (77% of reduction yield) could be reduced for the production of 1 kg of lactic acid compared with batch fermentation of a similar volumetric productivity. PMID:24561722

Lee, Ryun-Kyung; Ryu, Hwa-Won; Oh, Hurok; Kim, Mina; Wee, Young-Jung



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


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

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



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

PubMed Central

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

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



Succinic acid production from sucrose by Actinobacillus succinogenes NJ113.  


In this study, sucrose, a reproducible disaccharide extracted from plants, was used as the carbon source for the production of succinic acid by Actinobacillus succinogenes NJ113. During serum bottle fermentation, the succinic acid concentration reached 57.1g/L with a yield of 71.5%. Further analysis of the sucrose utilization pathways revealed that sucrose was transported and utilized via a sucrose phosphotransferase system, sucrose-6-phosphate hydrolase, and a fructose PTS. Compared to glucose utilization in single pathway, more pathways of A. succinogenes NJ113 are dependent on sucrose utilization. By changing the control strategy in a fed-batch culture to alleviate sucrose inhibition, 60.5g/L of succinic acid was accumulated with a yield of 82.9%, and the productivity increased by 35.2%, reaching 2.16g/L/h. Thus utilization of sucrose has considerable potential economics and environmental meaning. PMID:24393713

Jiang, Min; Dai, Wenyu; Xi, Yonglan; Wu, Mingke; Kong, Xiangping; Ma, Jiangfeng; Zhang, Min; Chen, Kequan; Wei, Ping



A Novel Sucrose Synthase Pathway for Sucrose Degradation in Cultured Sycamore Cells 1  

PubMed Central

Enzymes of sucrose degradation and glycolysis in cultured sycamore (Acer pseudoplatanus L.) cells were assayed and characterized in crude extracts and after partial purification, in an attempt to identify pathways for sucrose catabolism. Desalted cell extracts contained similar activities (20-40 nanomoles per milligram protein per minute) of sucrose synthase, neutral invertase, glucokinase, fructokinase, phosphofructokinase, and UDPglucose pyrophosphorylase (assayed with 2 micromolar pyrophosphate (PPi). PPi-linked phosphofructokinase activity was virtually dependent upon fructose 2,6-bisphosphate, and the maximum activity exceeded that of ATP-linked phosphofructokinase. Hexokinase activity, with glucose as substrate, was highly specific for ATP, whereas fructokinase activity was relatively nonspecific. At 1 millimolar nucleoside triphosphate, fructokinase activity decreased in the order: UTP > ATP > CTP > GTP. We propose two pathways for sucrose degradation. One involves invertase action, followed by classical glycolysis of hexose sugars, and the other is a novel pathway initiated by sucrose synthase. The Km for sucrose of sucrose synthase was severalfold lower than that of neutral invertase (15 versus 65 millimolar), which may determine carbon partitioning between the two pathways. The sucrose synthase pathway proposed involves cycling of uridylates and PPi. UDPglucose pyrophosphorylase, which is shown to be an effective `PPi-scavenger,' would consume PPi and form UTP. The UTP could be then utilized in the UTP-linked fructokinase reaction, thereby forming UDP for sucrose synthase. The source of PPi is postulated to arise from the back reaction of PPi-linked phosphofructokinase. Sycamore cells contained a substantial endogenous pool of PPi (about 3 nanomoles per gram fresh weight, roughly 1/10 the amount of ATP in these cells), and sufficient fructose 2,6-bisphosphate (0.09 nanomole per gram fresh weight) to activate the PPi-linked phosphofructokinase. Possible regulation and energetic differences between the sucrose synthase and invertase pathways are discussed. PMID:16664934

Huber, Steven C.; Akazawa, Takashi



The use of ion mobility mass spectrometry for isomer composition determination extracted from se-rich yeast.  


The isomer ratio determination of a selenium-containing metabolite produced by Se-rich yeast was performed. Electrospray ionization and ion mobility mass spectrometry (IM-MS) were unsuccessfully used in order to resolve the isomers according to their collisional cross section (CCS) difference. The isomer ratio determination of 2,3-dihydroxypropionylselenocystathionine was performed after multidimensional liquid chromatography preconcentration from a water extract of Se-rich yeast using preparative size exclusion, anion exchange, and capillary reverse phase columns coupled to IM-MS. 4'-nitrobenzo-15-crown-5 ether, a selective shift reagent (SSR), was added after the last chromatographic dimension in order to specifically increase the CCS of one of the isomers by the formation of a stable host-guest system with the crown ether. Both isomers were consequently fully resolved by IM-MS, and the relative ratio of the isomers was determined to be 11-13% and 87-89%. The present data compared favorably with the literature to support the analytical strategy despite the lack of an authentic standard for method validation. In addition, computational chemistry methods were successfully applied to design the SSR and to support the experimental data. PMID:25295845

Far, Johann; Delvaux, Cédric; Kune, Christopher; Eppe, Gauthier; de Pauw, Edwin



Yeast ecology of Kombucha fermentation  

Microsoft Academic Search

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

Ai Leng Teoh; Gillian Heard; Julian Cox



The sequential exposure to jasmonate, salicylic acid and yeast extract promotes sanguinarine accumulation in Argemone mexicana cell cultures.  


The effects of the sequential application of methyl jasmonate (MeJa), salicylic acid (SA) and yeast extract (YE) to Argemone mexicana cell cultures were compared to either the sole application of each elicitor, or to the three-partite mixture. The highest sanguinarine accumulation occurred using the sequential treatment (ninefold over unexposed control cultures), followed by the single application of YE (fivefold). The elicitor mixture produced less sanguinarine than sole exposure to YE but higher than MeJa alone. SA did not produce any effect. Transcripts corresponding to tyrosine decarboxylase and berberine bridge enzyme accumulated in treated cells, but did not correlate with alkaloid accumulation. Discrete epifluorescence foci, surrounding the nucleus and scattered throughout the cytoplasm of elicited cells, suggested the presence of alkaloid-accumulating vesicles which could participate in a mechanism to avoid sanguinarine toxicity. PMID:22009570

Trujillo-Villanueva, Karen; Rubio-Piña, Jorge; Monforte-González, Miriam; Ramírez-Benítez, Efraín; Vázquez-Flota, Felipe



Budding yeast protein extraction and purification for the study of function, interactions, and post-translational modifications.  


Homogenization by bead beating is a fast and efficient way to release DNA, RNA, proteins, and metabolites from budding yeast cells, which are notoriously hard to disrupt. Here we describe the use of a bead mill homogenizer for the extraction of proteins into buffers optimized to maintain the functions, interactions and post-translational modifications of proteins. Logarithmically growing cells expressing the protein of interest are grown in a liquid growth media of choice. The growth media may be supplemented with reagents to induce protein expression from inducible promoters (e.g. galactose), synchronize cell cycle stage (e.g. nocodazole), or inhibit proteasome function (e.g. MG132). Cells are then pelleted and resuspended in a suitable buffer containing protease and/or phosphatase inhibitors and are either processed immediately or frozen in liquid nitrogen for later use. Homogenization is accomplished by six cycles of 20 sec bead-beating (5.5 m/sec), each followed by one minute incubation on ice. The resulting homogenate is cleared by centrifugation and small particulates can be removed by filtration. The resulting cleared whole cell extract (WCE) is precipitated using 20% TCA for direct analysis of total proteins by SDS-PAGE followed by Western blotting. Extracts are also suitable for affinity purification of specific proteins, the detection of post-translational modifications, or the analysis of co-purifying proteins. As is the case for most protein purification protocols, some enzymes and proteins may require unique conditions or buffer compositions for their purification and others may be unstable or insoluble under the conditions stated. In the latter case, the protocol presented may provide a useful starting point to empirically determine the best bead-beating strategy for protein extraction and purification. We show the extraction and purification of an epitope-tagged SUMO E3 ligase, Siz1, a cell cycle regulated protein that becomes both sumoylated and phosphorylated, as well as a SUMO-targeted ubiquitin ligase subunit, Slx5. PMID:24300101

Szymanski, Eva Paige; Kerscher, Oliver



Yeast RNA Extraction Using Hot Phenol See Khrer and Domdey, 1991, Methods Enzymol., 194:398-405. Note: Prepare dry ice  

E-print Network

73 Yeast RNA Extraction Using Hot Phenol · See Köhrer and Domdey, 1991, Methods Enzymol., 194:398-405. Note: Prepare dry ice powder in bucket. Preheat phenol/AE to 65°C. Heated phenol should not be re. Immediately add 500 µl hot phenol/AE (see below). Vortex for 15 seconds. Incubate at 65°C for 5 minutes

Aris, John P.


Influence of Hen Age on the Response of Turkey Poults to Cold Stress, Escherichia coli Challenge, and Treatment with a Yeast Extract Antibiotic Alternative1  

Microsoft Academic Search

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

G. R. Huff; W. E. Huff; N. C. Rath; F. Solis; M. B. Farnell; A. M. Donoghue


Potato sucrose transporter expression in minor veins indicates a role in phloem loading.  

PubMed Central

The major transport form of assimilates in most plants is sucrose. Translocation from the mesophyll into the phloem for long-distance transport is assumed to be carrier mediated in many species. A sucrose transporter cDNA was isolated from potato by complementation of a yeast strain that is unable to grow on sucrose because of the absence of an endogenous sucrose uptake system and the lack of a secreted invertase. The deduced amino acid sequence of the potato sucrose transporter gene StSUT1 is highly hydrophobic and is 68% identical to the spinach sucrose transporter SoSUT1 (pS21). In yeast, the sensitivity of sucrose transport to protonophores and to an increase in pH is consistent with an active proton cotransport mechanism. Substrate specificity and inhibition by protein modifiers are similar to results obtained for sucrose transport into protoplasts and plasma membrane vesicles and for the spinach transporter, with the exception of a reduction in maltose affinity. RNA gel blot analysis shows that the StSUT1 gene is highly expressed in mature leaves, whereas stem and sink tissues, such as developing leaves, show only low expression. RNA in situ hybridization studies show that the transporter gene is expressed specifically in the phloem. Both the properties and the expression pattern are consistent with a function of the sucrose transporter protein in phloem loading. PMID:8312741

Riesmeier, J W; Hirner, B; Frommer, W B



Oligosaccharides Derived from Sucrose  

NASA Astrophysics Data System (ADS)

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.

Monsan, Pierre F.; Ouarné, Francois


Enhancing isomaltulose production by recombinant Escherichia coli producing sucrose isomerase: culture medium optimization containing agricultural wastes and cell immobilization.  


Isomaltulose is a structural isomer of sucrose commercially used in food industries. In this work, recombinant Escherichia coli producing sucrose isomerase (SIase) was used to convert sucrose into isomaltulose. To develop an economical industrial medium, untreated cane molasses (10.63 g l?¹), yeast extract (25.93 g l?¹), and corn steep liquor (10.45 g l?¹) were used as main culture compositions for SIase production. The relatively high SIase activity (14.50 ± 0.11 U mg DCW?¹) was obtained by the recombinant cells. To the best of our knowledge, this is the first investigation on SIase production by engineered E. coli using untreated cane molasses. The recombinant E. coli cells expressing the SIase gene were immobilized in calcium alginate gel in order to improve the efficiency of recycling. The immobilization was most effective with 2 % (w/v) sodium alginate and 3 % (w/v) calcium chloride. The optimal initial biomass for immobilization was 20 % (w/v, wet wt.), with a hardening time of 8 h for cell immobilization. The immobilized E. coli cells exhibited good stability for 30 batches with the productivity of 0.45 g isomaltulose g pellet?¹ h?¹. A continuous isomaltulose formation process using a column reactor remained stable for 40 days with 83 ± 2 % isomaltulose yield, which would be beneficial for economical production of isomaltulose. PMID:23300051

Li, Sha; Xu, Hong; Yu, Jianguang; Wang, Yanyuan; Feng, Xiaohai; Ouyang, Pingkai



Short-term temporal dynamics of yeast abundance on the tall fescue phylloplane.  


Six replicate trials were conducted to determine the short-term temporal dynamics and the effects of foliar applications of nutrients on the phylloplane yeast community of tall fescue (Festuca arundinacea Schreb.). In each trial, 2% sucrose + 0.5% yeast extract solution or sterile deionized water (control) was applied to the experiment plots. Twelve hours post-treatment (at 0600 hours), leaf samples were collected and yeast colony-forming units (cfu) were enumerated by dilution plating. This process was repeated at 1200, 1800, and 2400 hours in each trial. Significant differences were observed between the number of yeast cfu and the time at which the samples were collected. On average, the number of yeast cfu recovered was significantly less at 1800 hours and significantly greatest at 2400 hours when compared with all other sampling times. Averaged over all time intervals, we observed a trend of increased yeast abundance in turf treated with the nutrient solution compared with control treatments. In a separate investigation, atmospheric yeast abundance above the canopy of tall fescue was assessed in the morning (0900) and in the afternoon (1500) using a Thermo Andersen single stage viable particle sampler. In 5 of the 6 trials of this experiment, atmospheric yeast abundance was significantly greater in the morning than in the afternoon. Results suggest the following colonization model: phylloplane yeasts on tall fescue reproduce during the late evening and early morning, stabilize during the late morning and early afternoon through exchange of immigrants and emigrants, and decline during the late afternoon and (or) early evening. PMID:18389002

Nix, Shannon S; Burpee, Leon L; Jackson, Kimberly L; Buck, James W



A Four-Hour Yeast Bioassay for the Direct Measure of Estrogenic Activity in Wastewater without Sample Extraction, Concentration, or Sterilization  

PubMed Central

The assay described here represents an improved yeast bioassay that provides a rapid yet sensitive screening method for EDCs with very little hands-on time and without the need for sample preparation. Traditional receptor-mediated reporter assays in yeast were performed twelve to twenty four hours after ligand addition, used colorimetric substrates, and, in many cases, required high, non-physiological concentrations of ligand. With the advent of new chemiluminescent substrates a ligand-induced signal can be detected within thirty minutes using high picomolar to low nanomolar concentrations of estrogen. As a result of the sensitivity (EC50 for estradiol is ~ 0.7 nM) and the very short assay time (2-4 hours) environmental water samples can typically be assayed directly without sterilization, extraction, and concentration. Thus, these assays represent rapid and sensitive approaches for determining the presence of contaminants in environmental samples. As proof of principle, we directly assayed wastewater influent and effluent taken from a wastewater treatment plant in the El Paso, TX area for the presence of estrogenic activity. The data obtained in the four-hour yeast bioassay directly correlated with GC-mass spectrometry analysis of these same water samples. PMID:20074779

Balsiger, Heather A.; de la Torre, Roberto; Lee, Wen-Yee; Cox, Marc B.



The isolation of an unidentified factor from yeast extract for the formate-pyruvate exchange reaction in streptococcus faecalis  

E-print Network

added to the reaction mimture containing- yeast emtraot only a 2N riduotion of activity. was TAMIL 1, Bigratii-n ni' tho factor on loper in s pyridinc butcnol-i. ztsr solvent system. . Band Boo Color of bands hy u+ve Activity Fold apmspmols... added to the reaction mimture containing- yeast emtraot only a 2N riduotion of activity. was TAMIL 1, Bigratii-n ni' tho factor on loper in s pyridinc butcnol-i. ztsr solvent system. . Band Boo Color of bands hy u+ve Activity Fold apmspmols...

Chen, Chi-sin



Transcriptional activation of a geranylgeranyl diphosphate synthase gene, GGPPS2, isolated from Scoparia dulcis by treatment with methyl jasmonate and yeast extract.  


A cDNA clone, designated SdGGPPS2, was isolated from young seedlings of Scoparia dulcis. The putative amino acid sequence of the translate of the gene showed high homology with geranylgeranyl diphosphate synthase (GGPPS) from various plant sources, and the N-terminal residues exhibited the characteristics of chloroplast targeting sequence. An appreciable increase in the transcriptional level of SdGGPPS2 was observed by exposure of the leaf tissues of S. dulcis to methyl jasmonate, yeast extract or Ca(2+) ionophore A23187. In contrast, SdGGPPS1, a homologous GGPPS gene of the plant, showed no or only negligible change in the expression level upon treatment with these stimuli. The truncated protein heterologously expressed in Escherichia coli in which the putative targeting domain was deleted catalyzed the condensation of farnesyl diphosphate and isopentenyl diphosphate to liberate geranylgeranyl diphosphate. These results suggested that SdGGPPS2 plays physiological roles in methyl jasmonate and yeast extract-induced metabolism in the chloroplast of S. dulcis cells. PMID:25027024

Yamamura, Y; Mizuguchi, Y; Taura, F; Kurosaki, F



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


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

Hrazdina, Geza; Borejsza-Wysocki, W



Evolution of Plant Sucrose Uptake Transporters  

PubMed Central

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

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



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


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. and 6-SFT (6-sucrose:fructan fructosyltransferase, E.C., 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

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



Sucrose metabolism in lima bean seeds  

Microsoft Academic Search

Developing and germinating lima bean (Phaseolus lunatus var Cangreen) seeds were used for testing the sucrose synthase pathway, to examine the competition for uridine diphosphate (UDP) and pyrophosphate (PPi), and to identify adaptive and maintenance-type enzymes in glycolysis and gluconeogenesis. In developing seeds, sucrose breakdown was dominated by the sucrose synthase pathway; but in the seedling embryos, both the sucrose

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



Sugarcane genes associated with sucrose content  

Microsoft Academic Search

BACKGROUND -: Sucrose content is a highly desirable trait in sugarcane as the worldwide demand for cost-effective biofuels surges. Sugarcane cultivars differ in their capacity to accumulate sucrose and breeding programs routinely perform crosses to identify genotypes able to produce more sucrose. Sucrose content in the mature internodes reach around 20% of the culms dry weight. Genotypes in the populations

Flávia S Papini-Terzi; Flávia R Rocha; Ricardo ZN Vêncio; Juliana M Felix; Diana S Branco; Alessandro J Waclawovsky; Luiz EV Del Bem; Carolina G Lembke; Maximiller DL Costa; Milton Y Nishiyama; Renato Vicentini; Michel GA Vincentz; Eugênio C Ulian; Marcelo Menossi; Glaucia M Souza



Transcapillary Exchange and Retention of Fluoride, Strontium, EDTA, Sucrose, and Antipyrine in Bone  

PubMed Central

Summary The extractions of 85Sr2+, 18F?, sucrose-14C, EDTA-51Cr, and antipyrine-14C in bone were determined by the multiple indicator-dilution method. Fluoride and strontium extractions were 18 to 70% during a single transcapillary passage, and those of EDTA and sucrose were from 11 to 59%, whereas extraction of antipyrine was 87%. Injections of 85Sr2+ and 18F? made when perfusion was done alternately with blood and plasma resulted in similar fractional extractions. When flow and extraction were measured simultaneously, extraction was related inversely to flow. PMID:6770980

Lemon, Gerard J.; Davies, David R.; Hughes, Sean P.F.; Bassingthwaighte, James B.; Kelly, Patrick J.



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


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

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



Autophagic response of higher plant cells to a prolonged period of sucrose deprivation  

E-print Network

, Grenoble Cedex, France Introduction One of the most original properties of higher plant metabolism lies acid (PCA) extraction (Roby et aL, 1987), sucrose and starch determi- nations (Journet et al., 1986

Paris-Sud XI, Université de


Evaluation of red chicory extract as a natural antioxidant by pure lipid oxidation and yeast oxidative stress response as model systems.  


The search for renewable and abundant sources of antioxidants has recently focused on agricultural byproducts, especially promising due to their natural origins and low costs. In particular, plant raw materials are sources of important compounds such as dietary fiber, carotenoids, tocopherols, and polyphenolics, which are mostly discarded during harvesting and processing. Among these vegetal crops, red chicory is attractive because of the large quantity of its byproducts (residues as leaves and stems); moreover, there is no information on its role as a food and feed ingredient. In this study, red chicory leaf residue was evaluated as a natural substitute for synthetic antioxidants for the food and feed industry. After lyophilization, a red chicory extract (RC) was characterized for its phenolic profile and its oxidative stability as compared to BHT. RC was shown to reduce lipid peroxidation of different oils in the Rancimat test. In addition, the antioxidant property of RC was studied in a model system by evaluating the Saccharomyces cerevisiae response to oxidative stress by means of gene expression. In this analysis, the RC extract, added to the yeast culture prior to oxidative stress induction, exhibited a pleiotropic protective effect on stress responsive genes. PMID:21488640

Lante, Anna; Nardi, Tiziana; Zocca, Federico; Giacomini, Alessio; Corich, Viviana



Endogenous hydrogen peroxide is a key factor in the yeast extract-induced activation of biphenyl biosynthesis in cell cultures of Sorbus aucuparia.  


Biphenyls are unique phytoalexins produced by plants belonging to Pyrinae, a subtribe of the economically important Rosaceae family. The formation of aucuparin, a well-known biphenyl, is induced by yeast extract (YE) in cell cultures of Sorbus aucuparia. However, the molecular mechanism underlying YE-induced activation of biphenyl biosynthesis remains unknown. Here we demonstrate that the addition of YE to the cell cultures results in a burst of reactive oxygen species (ROS; H(2)O(2) and O(2) (-)), followed by transcriptional activation of the biphenyl synthase 1 gene (BIS1) encoding the key enzyme of the biphenyl biosynthetic pathway and aucuparin accumulation. Pretreatment of the cell cultures with ROS scavenger dihydrolipoic acid and NADPH oxidase-specific inhibitor diphenylene iodonium abolished all of the above YE-induced biological events. However, when the cell cultures was pretreated with superoxide dismutase specific inhibitor N,N-diethyldithiocarbamic acid, although O(2) (-) continued to be generated, the H(2)O(2) accumulation, BIS1 expression and aucuparin production were blocked. Interestingly, exogenous supply of H(2)O(2) in the range of 0.05-10 mM failed to induce aucuparin accumulation. These results indicate that endogenous generation of H(2)O(2) rather than that of O(2) (-) is a key factor in YE-induced accumulation of biphenyl phytoalexins in cell cultures of S. aucuparia. PMID:22086110

Qiu, Xiaofang; Lei, Caiyan; Huang, Lili; Li, Xing; Hao, He; Du, Zhigao; Wang, Hong; Ye, Hechun; Beerhues, Ludger; Liu, Benye



Xuezhikang, extract of red yeast rice, inhibited tissue factor and hypercoagulable state through suppressing nicotinamide adenine dinucleotide phosphate oxidase and extracellular signal-regulated kinase activation.  


Xuezhikang, extract of red yeast rice, is a traditional Chinese medicine with multiple cardioprotective effect. It contains a family of naturally occurring statins, such as lovastatin. Tissue factor (TF) is overexpressed in macrophages of lipid core plaques, which display high procoagulant activity and seem to be a potentially target for anti-atherothrombosis. Therefore, the purpose of this study was to explore the effect and possible molecular mechanisms of xuezhikang on inhibiting TF expression and hypercoagulable state and the differences compared with lovastatin. Our results showed that xuezhikang significantly suppressed oxidized low-density lipoprotein-induced TF expression in macrophages in a concentration-dependent manner. Xuezhikang reduced nicotinamide adenine dinucleotide phosphate oxidase activity by decreasing membrane translocation of p47 through inhibition of extracellular signal-regulated kinase 1/2 activation. Nicotinamide adenine dinucleotide phosphate inhibitor (diphenyleneiodonium) also inhibited the oxidized low-density lipoprotein-induced TF expression, similar to the effects of xuezhikang. Furthermore, consistent with the severity of aortic atherosclerosis, xuezhikang (300 mg·kg·d) significantly reduced blood coagulation activation and TF expression in high-cholesterol diet-induced atherosclerotic rats. In addition, xuezhikang was more potent than lovastatin on inhibiting the expression of TF and nicotinamide adenine dinucleotide phosphate oxidase activation. These observations provide evidences that inhibition of xuezhikang on hypercoagulation and TF expression may partly account for its cardioprotective benefits. PMID:21697731

Li, Pei; Yang, Yabing; Liu, Meilin



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

PubMed Central

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

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



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

Microsoft Academic Search

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

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



Characterization of Sucrolysis via the Uridine Diphosphate and Pyrophosphate-Dependent Sucrose Synthase Pathway 1  

PubMed Central

The breakdown of sucrose to feed both hexoses into glycolytic carbon flow can occur by the sucrose synthase pathway. This uridine diphosphate (UDP) and pyrophosphate (PPi)-dependent pathway was biochemically characterized using soluble extracts from several plants. The sucrolysis process required the simultaneous presence of sucrose, UDP, and PPi with their respective Km values being about 40 millimolar, 23 micromolar, and 29 micromolar. UDP was the only active nucleotide diphosphate. Slightly alkaline pH optima were observed for sucrose breakdown either to glucose 1-phosphate or to triose phosphate. Sucrolysis incrased with increasing temperature to near 50°C and then a sharp drop occurred between 55 and 60°C. The breakdown of sucrose to triose-P was activated by fructose 2,6-P2 which had a Km value near 0.2 micromolar. The cytoplasmic phosphofructokinase and fructokinase in plants were fairly nonselective for nucleotide triphosphates (NTP) but glucokinase definitely favored ATP. A predicted stoichiometric relationship of unity for UDP and PPi was measured when one also measured competing UDPase and pyrophosphatase activity. The cycling of uridylates, UDP to UTP to UDP, was demonstrated both with phosphofructokinase and with fructokinase. Enzyme activity measurements indicated that the sucrose synthase pathway has a major role in plant sucrose sink tissues. In the cytoplasmic sucrose synthase breakdown pathway, a role for the PPi-phosphofructokinase was to produce PPi while a role for the NTP-phosphofructokinase and for the fructokinase was to produce UDP. PMID:16666820

Xu, Dian-Peng; Sung, Shi-Jean S.; Loboda, Tadeusz; Kormanik, Paul P.; Black, Clanton C.



Inhibition by Natural Dietary Substances of Gastrointestinal Absorption of Starch and Sucrose in Rats 2. Subchronic Studies  

Microsoft Academic Search

Acute oral consumption of various natural inhibitors of amylase (bean and hibiscus extracts) and sucrase (L-arabinose) reduce absorption of starch and sucrose respectively in rats and pigs measured by lessened appearance of circulating glucose levels. The present subchronic study was designed to determine whether these selected inhibitors of gastrointestinal starch and sucrose absorption (so-called \\

Harry G. Preuss; Bobby Echard; Debasis Bagchi; Sidney Stohs


Sucrose-mediated translational control  

PubMed Central

Background Environmental factors greatly impact plant gene expression and concentrations of cellular metabolites such as sugars and amino acids. The changed metabolite concentrations affect the expression of many genes both transcriptionally and post-transcriptionally. Recent Progress Sucrose acts as a signalling molecule in the control of translation of the S1 class basic leucine zipper transcription factor (bZIP) genes. In these genes the main bZIP open reading frames (ORFs) are preceded by upstream open reading frames (uORFs). The presence of uORFs generally inhibits translation of the following ORF but can also be instrumental in specific translational control. bZIP11, a member of the S1 class bZIP genes, harbours four uORFs of which uORF2 is required for translational control in response to sucrose concentrations. This uORF encodes the Sucrose Control peptide (SC-peptide), which is evolutionarily conserved among all S1 class bZIP genes in different plant species. Arabidopsis thaliana bZIP11 and related bZIP genes seem to be important regulators of metabolism. These proteins are targets of the Snf1-related protein kinase 1 (SnRK1) KIN10 and KIN11, which are responsive to energy deprivation as well as to various stresses. In response to energy deprivation, ribosomal biogenesis is repressed to preserve cellular function and maintenance. Other key regulators of ribosomal biogenesis such as the protein kinase Target of Rapamycin (TOR) are tightly regulated in response to stress. Conclusions Plants use translational control of gene expression to optimize growth and development in response to stress as well as to energy deprivation. This Botanical Briefing discusses the role of sucrose signalling in the translational control of bZIP11 and the regulation of ribosomal biogenesis in response to metabolic changes and stress conditions. PMID:19376782

Hummel, Maureen; Rahmani, Fatima; Smeekens, Sjef; Hanson, Johannes



Yeast Infections  


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, ...


Mixed culture fermentation for the production of clinical quality dextran with starch and sucrose  

Microsoft Academic Search

Mixed culture fermentations containing a dextranase-producing yeast, Lipomyces starkeyi, and a dextransucrase-producing bacterium, Leuconostoc mesenteroides, produced dextrans of selected size using sucrose and starch. Dextran and starch hydrolyzates, produced by a Lipomyces starkeyi dextranase and amylase, were incorporated into the dextran and formed small size dextran (Mr = 40kDa). The yields of total and clinical dextran in mixed culture fermentation

Doman Kim; Deok-Young Jhon; Kwan-Hwa Park; Donal F. Day



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

PubMed Central

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

Sabri, Suriana; Nielsen, Lars K.



Mixed culture of Bacillus circulans WL12 and Phaffia Rhodozyma on different carbon sources: Yeast-wall lytic enzyme production and extractability of astaxanthin  

Microsoft Academic Search

Summary Lytic enzyme production byBacillus circulans WL-12 and modification of the red yeastPhaffia rhodozyma in mixed culture, is feasible on some simple sugars other than glucose. Advantages of the mixed culture are discussed.

R. N. Okagbue; M. J. Lewis



Model of the structure of sucrose solutions  

Microsoft Academic Search

1.The observed properties of the sucrose-water system over the entire range of concentrations investigated can be explained with the aid of the continual model of an aqueous solution of sucrose without calling upon the concept of a microscopic separation of phases.2.The model developed predicts a continual transition from the structure of a solution with a low concentration of sucrose to

I. S. Gulyi; V. M. Klimovich



Sucrose synthesis in gamma irradiated sweet potato  

SciTech Connect

Effect of ..cap alpha..-irradiation carbohydrate metabolism was examined to elucidate mechanism of sucrose accumulation in sweet potato (SP). Enzymes examined were: ..beta..-amylase, phosphorylase, phosphoglucomutase, phosphoglucose isomerase, sucrose phosphate synthetase and sucrose synthetase. Irradiated SP (Red Jewell) sucrose was synthesized to yield 10.7% after 4 d PI. Activities of sugar synthesizing enzymes in irradiated SP were enhanced to different degrees using 100-200 Krad and 3 d PI at 24/sup 0/C. Phosphorylase and phosphoglucomutases specific activities reached 2.4 and 1.8 folds, respectively compared to control SP. ..beta..-amylase, phosphoglucose isomerase, sucrose synthetase and sucrose phosphate synthetase were also affected to yield 1.2, 1.3, 1.3 and 1.2 folds, respectively compared to controls. It is believed that amylase hydrolyzed starch to glucose which is converted to fructose by phosphoglucose isomerase. Sucrose is then formed by sucrose phosphate synthetase and/or sucrose synthetase leading to its accumulation. The irradiated SP was used for alcohol fermentation leading to 500 gal. of 200 proof ethanol/acre (from 500-600 bushels tuber/acre).

Ailouni, S.; Hamdy, M.K.; Toledo, R.T.



Yeast ecology of Kombucha fermentation.  


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

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



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

E-print Network

Environmental stress Á Sucrose, starch, and cellulose metabolism Á Transgenic cotton C. H. Haigler (&) Á B-type and transgenic null controls. Leaves of transgenic SPS over-expressing lines showed higher sucrose:starch ra- tio and partitioning of 14 C to sucrose in preference to starch. In two growth chamber experiments with cool nights

Strauss, Richard E.


Transport of sucrose, not hexose, in the phloem  

PubMed Central

Several lines of evidence indicate that glucose and fructose are essentially absent in mobile phloem sap. However, this paradigm has been called into question, especially but not entirely, with respect to species in the Ranunculaceae and Papaveraceae. In the experiments in question, phloem sap was obtained by detaching leaves and placing the cut ends of the petioles in an EDTA solution. More hexose than sucrose was detected. In the present study, these results were confirmed for four species. However, almost identical results were obtained when the leaf blades were removed and only petiole stubs were immersed. This suggests that the sugars in the EDTA solution represent compounds extracted from the petioles, rather than sugars in transit in the phloem. In further experiments, the leaf blades were exposed to 14CO2 and, following a chase period, radiolabelled sugars in the petioles and EDTA exudate were identified. Almost all the radiolabel was in the form of [14C]sucrose, with little radiolabelled hexose. The data support the long-held contention that sucrose is a ubiquitous transport sugar, but hexoses are essentially absent in the phloem stream. PMID:22553289

Liu, David D.; Chao, Wesley M.; Turgeon, Robert



Functional Analysis of Arabidopsis Sucrose Transporters  

SciTech Connect

Sucrose is the main photosynthetic product that is transported in the vasculature of plants. The long-distance transport of carbohydrates is required to support the growth and development of net-importing (sink) tissues such as fruit, seeds and roots. This project is focused on understanding the transport mechanism sucrose transporters (SUTs). These are proton-coupled sucrose uptake transporters (membrane proteins) that are required for transport of sucrose in the vasculature and uptake into sink tissues. The accomplishments of this project included: 1) the first analysis of substrate specificity for any SUT. This was accomplished using electrophysiology to analyze AtSUC2, a sucrose transporter from companion cells in Arabidopsis. 2) the first analysis of the transport activity for a monocot SUT. The transport kinetics and substrate specificity of HvSUT1 from barley were studied. 3) the first analysis of a sucrose transporter from sugarcane. and 4) the first analysis of transport activity of a sugar alcohol transporter homolog from plants, AtPLT5. During this period four primary research papers, funded directly by the project, were published in refereed journals. The characterization of several sucrose transporters was essential for the current effort in the analysis of structure/function for this gene family. In particular, the demonstration of strong differences in substrate specificity between type I and II SUTs was important to identify targets for site-directed mutagenesis.

John M. Ward



Sucrose-Utilizing Transglucosidases for Biocatalysis  

NASA Astrophysics Data System (ADS)

Sucrose-utilizing transglucosidases are valued tools in chemistry to generate glycodiversification. Not only do these enzymes use as substrate an abundant agroresource, sucrose, but they also share a remarkable versatility regarding the acceptor substrate, allowing the structurally-controlled synthesis of diverse glucosylated products. Latest research has demonstrated the potential of enzyme engineering to tailor novel sucrose-utilizing transglucosidases that give access to original carbohydrate-based structures. This chapter gives an overview of the recent achievements in biocatalysis using these enzymes.

André, Isabelle; Potocki-Véronèse, Gabrielle; Morel, Sandrine; Monsan, Pierre; Remaud-Siméon, Magali


Production and characterization of a novel yeast extracellular invertase activity towards improved dibenzothiophene biodesulfurization.  


The main goal of this work was the production and characterization of a novel invertase activity from Zygosaccharomyces bailii strain Talf1 for further application to biodesulfurization (BDS) in order to expand the exploitable alternative carbon sources to renewable sucrose-rich feedstock. The maximum invertase activity (163 U ml(-1)) was achieved after 7 days of Z. bailii strain Talf1 cultivation at pH 5.5-6.0, 25 °C, and 150 rpm in Yeast Malt Broth with 25 % Jerusalem artichoke pulp as inducer substrate. The optimum pH and temperature for the crude enzyme activity were 5.5 and 50 °C, respectively, and moreover, high stability was observed at 30 °C for pH 5.5-6.5. The application of Talf1 crude invertase extract (1 %) to a BDS process by Gordonia alkanivorans strain 1B at 30 °C and pH 7.5 was carried out through a simultaneous saccharification and fermentation (SSF) approach in which 10 g l(-1) sucrose and 250 ?M dibenzothiophene were used as sole carbon and sulfur sources, respectively. Growth and desulfurization profiles were evaluated and compared with those of BDS without invertase addition. Despite its lower stability at pH 7.5 (loss of activity within 24 h), Talf1 invertase was able to catalyze the full hydrolysis of 10 g l(-1) sucrose in culture medium into invert sugar, contributing to a faster uptake of the monosaccharides by strain 1B during BDS. In SSF approach, the desulfurizing bacterium increased its ?max from 0.035 to 0.070 h(-1) and attained a 2-hydroxybiphenyl productivity of 5.80 ?M/h in about 3 days instead of 7 days, corresponding to an improvement of 2.6-fold in relation to the productivity obtained in BDS process without invertase addition. PMID:25163885

Arez, Bruno F; Alves, Luís; Paixão, Susana M



Yeast 14, 14531469 (1998) Expanding Yeast Knowledge Online  

E-print Network

YEAST Yeast 14, 1453­1469 (1998) Expanding Yeast Knowledge Online KARA DOLINSKI1 , CATHERINE A in the amount of new yeast genetics and molecular biology data. Efficient organization, presentation Sequences; Yeast Protein Database CONTENTS Introduction

Botstein, David


Intracellular sucrose communicates metabolic demand to sucrose transporters in developing pea cotyledons  

PubMed Central

Mechanistic inter-relationships in sinks between sucrose compartmentation/metabolism and phloem unloading/translocation are poorly understood. Developing grain legume seeds provide tractable experimental systems to explore this question. Metabolic demand by cotyledons is communicated to phloem unloading and ultimately import by sucrose withdrawal from the seed apoplasmic space via a turgor-homeostat mechanism. What is unknown is how metabolic demand is communicated to cotyledon sucrose transporters responsible for withdrawing sucrose from the apoplasmic space. This question was explored here using a pea rugosus mutant (rrRbRb) compromised in starch biosynthesis compared with its wild-type counterpart (RRRbRb). Sucrose influx into cotyledons was found to account for 90% of developmental variations in their absolute growth and hence starch biosynthetic rates. Furthermore, rr and RR cotyledons shared identical response surfaces, indicating that control of transporter activity was likely to be similar for both lines. In this context, sucrose influx was correlated positively with expression of a sucrose/H+ symporter (PsSUT1) and negatively with two sucrose facilitators (PsSUF1 and PsSUF4). Sucrose influx exhibited a negative curvilinear relationship with cotyledon concentrations of sucrose and hexoses. In contrast, the impact of intracellular sugars on transporter expression was transporter dependent, with expression of PsSUT1 inhibited, PsSUF1 unaffected, and PsSUF4 enhanced by sugars. Sugar supply to, and sugar concentrations of, RR cotyledons were manipulated using in vitro pod and cotyledon culture. Collectively the results obtained showed that intracellular sucrose was the physiologically active sugar signal that communicated metabolic demand to sucrose influx and this transport function was primarily determined by PsSUT1 regulated at the transcriptional level. PMID:18931350

Zhou, Yuchan; Chan, Katie; Wang, Trevor L.; Hedley, Cliff L.; Offler, Christina E.; Patrick, John W.



Time-dependent changes in suspensions of sucrose powder in saturated sucrose solution  

Microsoft Academic Search

Viscous and pseudoplastic fluids were prepared at 1:2.1, 1:2.3 and 1:2.5 proportions of saturated aqueous sucrose solution to sucrose powder. These specimens gradually became more solid-like upon storage for two weeks in closed containers. Scanning electron microscopy revealed time-dependent changes in microstructure accompanying the redistribution of sucrose molecules in these specimens. These changes included: (1) an increased particle size from

Marek Sikora; Christopher H. Schilling; Piotr Tomasik; Marek Sady



Bacterial sucrose isomerases: properties and structural studies  

Microsoft Academic Search

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

Moez Rhimi; Richard Haser; Nushin Aghajari



Wear of metals in sucrose solutions  

Microsoft Academic Search

The authors studied the wear of steel St. 5 rubbing against cast iron SCh 15–32, bronzes BrOTsS 5-5-5 and Br. AZh 9-4, and babbitt BN in aqueous solutions containing up to 80% sucrose. It was established that at sucrose concentrations of up to 60% the maximum resistance to wear is displayed by the St. 5\\/Br. OTsS 5-5-5 combination and the

N. A. Sologub



The quest for a thermostable sucrose phosphorylase reveals sucrose 6'-phosphate phosphorylase as a novel specificity.  


Sucrose phosphorylase is a promising biocatalyst for the glycosylation of a wide range of compounds, but its industrial application has been hampered by the low thermostability of known representatives. Hence, in this study, the putative sucrose phosphorylase from the thermophile Thermoanaerobacterium thermosaccharolyticum was recombinantly expressed and fully characterised. The enzyme showed significant activity on sucrose (optimum at 55 °C), and with a melting temperature of 79 °C and a half-life of 60 h at the industrially relevant temperature of 60 °C, it is far more stable than known sucrose phosphorylases. Substrate screening and detailed kinetic characterisation revealed however a preference for sucrose 6'-phosphate over sucrose. The enzyme can thus be considered as a sucrose 6'-phosphate phosphorylase, a specificity not yet reported to date. Homology modelling and mutagenesis pointed out particular residues (Arg134 and His344) accounting for the difference in specificity. Moreover, phylogenetic and sequence analysis suggest that glycoside hydrolase 13 subfamily 18 might harbour even more specificities. In addition, the second gene residing in the same operon as sucrose 6'-phosphate phosphorylase was identified as well, and found to be a phosphofructokinase. The concerted action of both these enzymes implies a new pathway for the breakdown of sucrose, in which the reaction products end up at different stages of the glycolysis. PMID:24599311

Verhaeghe, Tom; Aerts, Dirk; Diricks, Margo; Soetaert, Wim; Desmet, Tom



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.  


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 250W, HAc% of 7.7%, RYR amount of 0.2g (solvent-to-solid ratio 40mL/g), extraction time of 50.7min, 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

Zhou, Guisheng; Fu, Lei; Li, Xiaobo



High power density yeast catalyzed microbial fuel cells  

NASA Astrophysics Data System (ADS)

Microbial fuel cells leverage whole cell biocatalysis to convert the energy stored in energy-rich renewable biomolecules such as sugar, directly to electrical energy at high efficiencies. Advantages of the process include ambient temperature operation, operation in natural streams such as wastewater without the need to clean electrodes, minimal balance-of-plant requirements compared to conventional fuel cells, and environmentally friendly operation. These make the technology very attractive as portable power sources and waste-to-energy converters. The principal problem facing the technology is the low power densities compared to other conventional portable power sources such as batteries and traditional fuel cells. In this work we examined the yeast catalyzed microbial fuel cell and developed methods to increase the power density from such fuel cells. A combination of cyclic voltammetry and optical absorption measurements were used to establish significant adsorption of electron mediators by the microbes. Mediator adsorption was demonstrated to be an important limitation in achieving high power densities in yeast-catalyzed microbial fuel cells. Specifically, the power densities are low for the length of time mediator adsorption continues to occur. Once the mediator adsorption stops, the power densities increase. Rotating disk chronoamperometry was used to extract reaction rate information, and a simple kinetic expression was developed for the current observed in the anodic half-cell. Since the rate expression showed that the current was directly related to microbe concentration close to the electrode, methods to increase cell mass attached to the anode was investigated. Electrically biased electrodes were demonstrated to develop biofilm-like layers of the Baker's yeast with a high concentration of cells directly connected to the electrode. The increased cell mass did increase the power density 2 times compared to a non biofilm fuel cell, but the power density increase was shown to quickly saturate with cell mass attached on the electrode. Based on recent modelling data that suggested that the electrode currents might be limited by the poor electrical conductivity of the anode, the power density versus electrical conductivity of a yeast-immobilized anode was investigated. Introduction of high aspect ratio carbon fiber filaments to the immobilization matrix increased the electrical conductivity of the anode. Although a higher electrical conductivity clearly led to an increase in power densities, it was shown that the principal limitation to power density increase was coming from proton transfer limitations in the immobilized anode. Partial overcoming of the gradients lead a power density of ca. 250 microW cm-2, which is the highest reported for yeast powered MFCs. A yeast-catalyzed microbial fuel cell was investigated as a power source for low power sensors using raw tree sap. It was shown that yeast can efficiently utilize the sucrose present in the raw tree sap to produce electricity when excess salt is added to the medium. Therefore the salinity of a potential energy source is an important consideration when MFCs are being considered for energy harvesting from natural sources.

Ganguli, Rahul


Effect of operating conditions on water transport during the concentration of sucrose solutions by osmotic distillation  

Microsoft Academic Search

A recent membrane technique, osmotic distillation (OD), is used to concentrate binary water–sucrose solutions at ambient temperature under atmospheric pressure. The principle is based on the extraction of water vapour from a dilute aqueous solution, which is put in contact with a hypertonic salt solution by means of a macroporous hydrophobic membrane. The concentration difference between both solutions translates into

Mathilde Courel; Manuel Dornier; Jean-Marie Herry; Gilbert Marcel Rios; Max Reynes



Sucrose-Phosphate Synthase, Sucrose Synthase, and Invertase in Sugar Beet Leaves  

Microsoft Academic Search

The activity of sucrose-phosphate synthase (SPS) in sugar beet (Beta vulgaris L.) leaves was shown to exceed considerably the synthesizing activity of sucrose synthase (SS). The rise in SPS activity was related to the daylight period; i.e., it was associated with the rate of photosynthesis. The highest SPS activity was characteristic of fully expanded source leaves. In young developing leaves

O. A. Pavlinova; E. N. Balakhontsev; M. F. Prasolova; M. V. Turkina



Effects of sucrose on the extracellular matrix of plaque-like biofilm formed in vivo, studied by proteomic analysis.  


Previous studies have shown that sucrose promotes changes in the composition of the extracellular matrix (ECM) of plaque-like biofilm (PLB), but its effect on protein expression has not been studied in vivo. Therefore, the protein compositions of ECM of PLB formed with and without sucrose exposure were analyzed by two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). For this purpose, a crossover study was conducted during two phases of 14 days each, during which a volunteer wore a palatal appliance containing eight enamel blocks for PLB accumulation. In each phase, a 20% sucrose solution or distilled and deionized water (control) were extraorally dripped onto the blocks 8x/day. On the 14th day, the PLB were collected, the ECM proteins were extracted, separated by two-dimensional gel electrophoresis, digested by in-gel trypsin and MALDI-TOF MS analyzed. In the ECM of PLB formed under sucrose exposure, the following changes compared with the control PLB were observed: (1) the presence of upregulated proteins that may be involved in bacterial response to environmental changes induced by sucrose and (2) the absence of calcium-binding proteins that may partly explain the low inorganic concentration found in ECM of PLB formed under sucrose exposure. The findings showing that sucrose affected the ECM protein composition of PLB in vivo provide further insight into the unique cariogenic properties of this dietary carbohydrate. PMID:18832830

Paes Leme, A F; Bellato, C M; Bedi, G; Cury, A A Del Bel; Koo, H; Cury, J A



Sucrose transporter plays a role in phloem loading in CMV-infected melon plants that are defined as symplastic loaders.  


Based on the high density of plasmodesmata interconnecting the intermediary cells and their neighboring phloem parenchyma or bundle-sheath cells, and based on the insensitivity to the sucrose transport inhibitor p-chloromercuribenzenesulfonic acid (PCMBS), cucurbits have been concluded to be symplastic loaders. In the present study, we identified and characterized the full-length sequence of sucrose transporter gene (CmSUT1) from melon (Cucumis melo L. cv. Hale's best jumbo). In vitro experiments confirmed that the identified gene product has sucrose transporter activity in baker's yeast. Healthy and cucumber mosaic virus (CMV)-infected melon plants were employed to examine sucrose transporter activity in planta. Pretreatment with PCMBS inhibited loading of newly fixed ¹?CO? into minor veins of CMV-infected plants. Moreover, CMV infection caused significant increase in CmSUT1 transcripts expression, mainly in vascular bundles of minor veins, which was associated with elevated sucrose content in phloem sap collected from source-leaf petioles. We propose that cucurbit plants contain the machinery for apoplastic phloem loading and that CMV infection causes a quantitative shift in the mode by which photoassimilates are loaded into the sieve tube. PMID:21241389

Gil, Lidor; Yaron, Imry; Shalitin, Dror; Sauer, Norbert; Turgeon, Robert; Wolf, Shmuel



The conservation of waterlogged wood using sucrose  

E-print Network

was treated with aqueous solutions of sucrose and with type "A" sugar. The results of the two treatments were examined for parity. 2. The cell structure of various samples was examined by the use of light microscopy as well as transmission and scanning... was treated with aqueous solutions of sucrose and with type "A" sugar. The results of the two treatments were examined for parity. 2. The cell structure of various samples was examined by the use of light microscopy as well as transmission and scanning...

Parrent, James Michael



A novel sucrose phosphorylase from the metagenomes of sucrose-rich environment: isolation and characterization.  


Sucrose phosphorylase, an important enzyme mainly involved in the generic starch and sucrose pathways, has now caught the attention of researchers due to its transglycosylation activity. A novel sucrose phosphorylase, unspase, has been isolated, and its transglycosylation properties were characterized. Compared with Bisp, the sucrose phosphorylase from Bifidobacterium adolescentis, unspase had two deleted regions in its C: -terminal. These deleted regions were probably equivalent to the important five-stranded anti-parallel ?-sheet domain in sucrose phosphorylase. Unspase has a k(m) of 21.12 mM, a V(max) of 69.24 ?mol min(-1) mg(-1) and a k(cat) of 31.19 s(-1) with sucrose as substrate. In 3-(N-morpholino) propanesulfonic acid (MOPS) buffer, unspase transferred the glycosyl moiety to L-arabinose, D-fructose and L-sorbose. Much to our surprise, unspase can catalyze the transglycosylation in which a glycosyl moiety was transferred to L-arabinose in the presence of phosphate, which is an interesting exception to the generally accepted fact that transglycosylation can only occur under the condition of phosphate absence. The final yield of the transglycosylation product (37.9 %) in phosphate buffer was even higher than that (5.8 %) in MOPS buffer. This is a novel phenomenon that a sucrose phosphorylase can catalyze a transglycosylation reaction in the presence of phosphate. PMID:22806728

Du, Liqin; Yang, Hui; Huo, Yunlong; Wei, Hang; Xu, Yuanjin; Wei, Yutuo; Huang, Ribo



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


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

Kouassi, K; Roos, Y H



Components of the yeast spindle and spindle pole body  

Microsoft Academic Search

Yeast spindle pole bodies (SPBs) with at- tached nuclear microtubules were enriched ,x,600-fold from yeast cell extracts. 14 mAbs prepared against this enriched SPB fraction define at least three components of the SPB and spindle. Immunofluorescent staining of yeast cells showed that throughout the cell cycle two of the components (110 and 90 kD) were localized ex- clusively to the

Michael P. Rout; John V. Kilmartin



Dental caries: Possible sugar substitutes for sucrose  

Microsoft Academic Search

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

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



Comparison of melibiose utilizing baker's yeast strains produced by genetic engineering and classical breeding.  


Yeast strains currently used in the baking industry cannot fully utilize the trisaccharide raffinose found in beet molasses due to the absence of melibiase (alpha-galactosidase) activity. To overcome this deficiency, the MEL1 gene encoding melibiase enzyme was introduced into baker's yeast by both classical breeding and recombinant DNA technology. Both types of yeast strains were capable of vigorous fermentation in the presence of high levels of sucrose, making them suitable for the rapidly developing Asian markets where high levels of sugar are used in bread manufacture. Melibiase expression appeared to be dosage-dependent, with relatively low expression sufficient for complete melibiose utilization in a model fermentation system. PMID:10063644

Vincent, S F; Bell, P J; Bissinger, P; Nevalainen, K M



Sucrose phosphorylases catalyze transglycosylation reactions on carboxylic acid compounds  

Microsoft Academic Search

Two sucrose phosphorylases were employed for glycosylation of carboxylic acid compounds. Streptococcus mutans sucrose phosphorylase showed remarkable transglycosylating activity, especially under acidic conditions. Leuconostoc mesenteroides sucrose phosphorylase exhibited very weak transglycosylating activity. Three main products were detected from the reaction\\u000a mixture using benzoic acid and sucrose as an acceptor and a donor molecule, respectively. These compounds were identified\\u000a as 1-O-benzoyl

Kazuhisa Sugimoto; Koji Nomura; Hiromi Nishiura; Kohji Ohdan; Takahisa Nishimura; Hideo Hayashi; Takashi Kuriki



Vitrification of emulsified dilute aqueous sucrose solutions at high pressures  

NASA Astrophysics Data System (ADS)

The supercooling and glass-forming behavior of aqueous sucrose solution was investigated using emulsified sucrose solutions at high pressures. It is shown that emulsified aqueous sucrose solution with the sucrose concentration being as low as 1 m (m: molality) is glass-forming at high pressures above 190 MPa. This finding may form the basis of a useful vitrification method for cryo-preservation of living cells and tissues at high pressures.

Kanno, H.; Miyata, K.; Hayakawa, S.; Kajiwara, K.



Vitrification of emulsified dilute aqueous sucrose solutions at high pressures  

Microsoft Academic Search

The supercooling and glass-forming behavior of aqueous sucrose solution was investigated using emulsified sucrose solutions at high pressures. It is shown that emulsified aqueous sucrose solution with the sucrose concentration being as low as 1m (m: molality) is glass-forming at high pressures above 190MPa. This finding may form the basis of a useful vitrification method for cryo-preservation of living cells

H. Kanno; K. Miyata; S. Hayakawa; K. Kajiwara



Naloxone attenuates incubated sucrose craving in rats  

PubMed Central

Rationale Cue-induced craving precedes drug relapse and contributes to eating disorders. Opiate antagonists have been demonstrated to be effective at reducing cravings for drugs and food. Craving, as defined as responding for a stimulus previously associated with a reward, increases, or incubates, over forced abstinence in an animal model of relapse. Objectives This paper aims to determine anticraving effects of the opiate antagonist, naloxone, on the incubation of sucrose craving. Methods 106 male Long-Evans rats lever pressed for 10% sucrose solution 2 h/day for 10 days. On either day 1 or 30 of forced abstinence, rats responded in extinction for 6 h and then were injected (ip) with either saline or naloxone (0.001, 0.01, 0.1, 1, or 10 mg/kg). The rats then responded for 1 h for presentation of a tone+light cue previously presented with every sucrose delivery during self-administration training. Results The rats responded more in extinction and following saline on day 30 vs day 1 (an incubation of craving). Except for a trend for a decrease in responding following 10 mg/kg on day 1, naloxone was primarily effective on day 30. On day 30, naloxone significantly reduced responding at all doses except for 0.1 mg/kg. Conclusions The time-dependent increase in sensitivity to an opiate antagonist is consistent with time-dependent changes in the opiate system following forced abstinence from sucrose. These changes may partly underlie the incubation of sucrose craving. In addition, these findings could be used to support the use of naloxone as an anticraving medication in protracted abstinence. PMID:17628789

Manaois, Meghan; Osincup, Dan; Wells, Barbara; Buse, Carl



Fermentation Studies on Extracts of Beet.  

National Technical Information Service (NTIS)

Fodder beet juice and sugar beet juice were found to be good substrates for the production of ethanol. Two strains of flocculent yeast were selected to ferment fodder beet juice and sugar beet juice. Strain CFCC 8 fermented 10% w/v sucrose-equivalent fodd...

J. M. Smith



Sugar, water and free volume networks in concentrated sucrose solutions  

E-print Network

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

Goddard III, William A.


Energy characteristics of structures in aqueous solutions of sucrose  

Microsoft Academic Search

Structures arising in sucrose solutions of various concentrations are modeled. A computer simulation by the molecular mechanics\\u000a method proves the existence of three aqueous sucrose structures, which depends on the ratio between water and sucrose molecules.\\u000a The calculated data are in good agreement with the experimental results obtained by different methods.

L. D. Bobrovnik; A. M. Grekhov; I. S. Gulyi



Concentration of sucrose solutions via vacuum membrane distillation  

Microsoft Academic Search

The potential use of vacuum membrane distillation (VMD) process for the concentration of sucrose solution was examined. The effect of several parameters, including feed temperature, flow rate, and initial sucrose concentration on the flux quality and quantity was studied. VMD process was found effective in concentrating aqueous sucrose solutions as the permeate was absolutely pure water. The feed temperature significantly

S. Al-Asheh; F. Banat; M. Qtaishat; M. Al-Khateeb



Yeast Based Sensors  

NASA Astrophysics Data System (ADS)

Since the first microbial cell sensor was studied by Karube et al. in 1977, many types of yeast based sensors have been developed as analytical tools. Yeasts are known as facultative anaerobes. Facultative anaerobes can survive in both aerobic and anaerobic conditions. The yeast based sensor consisted of a DO electrode and an immobilized omnivorous yeast. In yeast based sensor development, many kinds of yeast have been employed by applying their characteristics to adapt to the analyte. For example, Trichosporon cutaneum was used to estimate organic pollution in industrial wastewater. Yeast based sensors are suitable for online control of biochemical processes and for environmental monitoring. In this review, principles and applications of yeast based sensors are summarized.

Shimomura-Shimizu, Mifumi; Karube, Isao


Protein expression-yeast.  


Yeast is an excellent system for the expression of recombinant eukaryotic proteins. Both endogenous and heterologous proteins can be overexpressed in yeast (Phan et al., 2001; Ton and Rao, 2004). Because yeast is easy to manipulate genetically, a strain can be optimized for the expression of a specific protein. Many eukaryotic proteins contain posttranslational modifications that can be performed in yeast but not in bacterial expression systems. In comparison with mammalian cell culture expression systems, growing yeast is both faster and less expensive, and large-scale cultures can be performed using fermentation. While several different yeast expression systems exist, this chapter focuses on the budding yeast Saccharomyces cerevisiae and will briefly describe some options to consider when selecting vectors and tags to be used for protein expression. Throughout this chapter, the expression and purification of yeast eIF3 is shown as an example alongside a general scheme outline. PMID:24423273

Nielsen, Klaus H



Dopaminergic and opiate agonists and antagonists differentially decrease multiple schedule responding maintained by sucrose\\/ethanol and sucrose  

Microsoft Academic Search

Similar neurobiological mechanisms are hypothesized to influence ethanol- and food-related reinforcement processes. This study examined the ability of compounds with dopaminergic or opiate activity to selectively alter responding maintained by a sucrose\\/ethanol solution in comparison to a sucrose solution. Long-Evans rats were trained to press a lever using 5% sucrose\\/10% ethanol and 5% sucrose as the reinforcers on a multiple

Craig J. Slawecki; Clyde W. Hodge; Herman H. Samson



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


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

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




E-print Network

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 rate of growth, with a generation time of only ninety minutes under optimal conditions. Genetic methods

Winston, Fred


[Yeasts contaminating salmon roe].  


Quantitative and species compositions of yeast contaminating eggs, fry and fingerlings of Salmo gairdneri Rich under artificial breeding have been studied. Prevalence of species of genera Candida, Rhodotorula, Cryptococcus and Debaryomyces is noted. Yeast isolated from perished eggs and sick fry do not possess pathogenic properties. Certain strains of yeast make stimulating effect on the studied microorganisms. PMID:8983527

Nagornaia, S S; Ignatova, E A; Isaeva, N M; Davydov, O N; Podgorski?, V S



CLONTECHInnovative Yeast Protocols Handbook  

E-print Network

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

Erickson, F. Les


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

PubMed Central

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

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



Biosynthesis of levan, a bacterial extracellular polysaccharide, in the yeast Saccharomyces cerevisiae.  


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

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



Biochemical and genomic analysis of sucrose metabolism during coffee (Coffea arabica) fruit development  

Microsoft Academic Search

Sucrose metabolism and the role of sucrose synthase were investigated in the fruit tissues (pericarp, peri- sperm, and endosperm) of Coffea arabica during development. Acid invertase, sucrose phosphate synthase, and sucrose synthase activities were moni- tored and compared with the levels of sucrose and reducing sugars. Among these enzymes, sucrose synthase showed the highest activities during the last stage of

Clara Geromel; Lucia Pires Ferreira; Sandra Maria Carmelo Guerreiro; Aline Andreia Cavalari; David Pot; Luiz Filipe; Protasio Pereira; Thierry Leroy; Luiz Gonzaga Esteves Vieira; Paulo Mazzafera; Pierre Marraccini



Crystallization inhibition of an amorphous sucrose system using raffinose*  

PubMed Central

The shelf life of pure amorphous sucrose systems, such as cotton candy, can be very short. Previous studies have shown that amorphous sucrose systems held above the glass transition temperature will collapse and crystallize. One study, however, showed that adding a small percent of another type of sugar, such as trehalose, to sucrose can extend the shelf life of the amorphous system by slowing crystallization. This study explores the hypothesis that raffinose increases the stability of an amorphous sucrose system. Cotton candy at 5 wt% raffinose and 95 wt% sucrose was made and stored at room temperature and three different relative humidities (%RH) 11%RH, 33%RH, and 43%RH. XRD patterns, and glass transition temperatures were obtained to determine the stability as a function of %RH. The data collected showed that raffinose slows sucrose crystallization in a low moisture amorphous state above the glass transition temperature and therefore improves the stability of amorphous sucrose systems. PMID:16421962

Leinen, K.M.; Labuza, T.P.



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

Microsoft Academic Search

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

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



Isolation and characterization of ethanol tolerant yeast strains.  


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

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



Transcription factors, sucrose, and sucrose metabolic genes interact to regulate potato phenylpropanoid metabolism  

PubMed Central

Much remains unknown about how transcription factors and sugars regulate phenylpropanoid metabolism in tuber crops like potato (Solanum tuberosum). Based on phylogeny and protein similarity to known regulators of phenylpropanoid metabolism, 15 transcription factors were selected and their expression was compared in white, yellow, red, and purple genotypes with contrasting phenolic and anthocyanin profiles. Red and purple genotypes had increased phenylalanine ammonia lyase (PAL) enzyme activity, markedly higher levels of phenylpropanoids, and elevated expression of most phenylpropanoid structural genes, including a novel anthocyanin O-methyltransferase. The transcription factors Anthocyanin1 (StAN1), basic Helix Loop Helix1 (StbHLH1), and StWD40 were more strongly expressed in red and purple potatoes. Expression of 12 other transcription factors was not associated with phenylpropanoid content, except for StMYB12B, which showed a negative relationship. Increased expression of AN1, bHLH1, and WD40 was also associated with environmentally mediated increases in tuber phenylpropanoids. Treatment of potato plantlets with sucrose induced hydroxycinnamic acids, flavonols, anthocyanins, structural genes, AN1, bHLH1, WD40, and genes encoding the sucrose-hydrolysing enzymes SUSY1, SUSY4, and INV2. Transient expression of StAN1 in tobacco leaves induced bHLH1, structural genes, SUSY1, SUSY4, and INV1, and increased phenylpropanoid amounts. StAN1 infiltration into tobacco leaves decreased sucrose and glucose concentrations. In silico promoter analysis revealed the presence of MYB and bHLH regulatory elements on sucrolytic gene promoters and sucrose-responsive elements on the AN1 promoter. These findings reveal an interesting dynamic between AN1, sucrose, and sucrose metabolic genes in modulating potato phenylpropanoids. PMID:24098049

Payyavula, Raja S.; Navarre, Duroy A.



Transport and Sorting of the Solanum tuberosum Sucrose Transporter SUT1 Is Affected by Posttranslational Modification[W  

PubMed Central

The plant sucrose transporter SUT1 from Solanum tuberosum revealed a dramatic redox-dependent increase in sucrose transport activity when heterologously expressed in Saccharomyces cerevisiae. Plant plasma membrane vesicles do not show any change in proton flux across the plasma membrane in the presence of redox reagents, indicating a SUT1-specific effect of redox reagents. Redox-dependent sucrose transport activity was confirmed electrophysiologically in Xenopus laevis oocytes with SUT1 from maize (Zea mays). Localization studies of green fluorescent protein fusion constructs showed that an oxidative environment increased the targeting of SUT1 to the plasma membrane where the protein concentrates in 200- to 300-nm raft-like microdomains. Using plant plasma membranes, St SUT1 can be detected in the detergent-resistant membrane fraction. Importantly, in yeast and in plants, oxidative reagents induced a shift in the monomer to dimer equilibrium of the St SUT1 protein and increased the fraction of dimer. Biochemical methods confirmed the capacity of SUT1 to form a dimer in plants and yeast cells in a redox-dependent manner. Blue native PAGE, chemical cross-linking, and immunoprecipitation, as well as the analysis of transgenic plants with reduced expression of St SUT1, confirmed the dimerization of St SUT1 and Sl SUT1 (from Solanum lycopersicum) in planta. The ability to form homodimers in plant cells was analyzed by the split yellow fluorescent protein technique in transiently transformed tobacco (Nicotiana tabacum) leaves and protoplasts. Oligomerization seems to be cell type specific since under native-like conditions, a phloem-specific reduction of the dimeric form of the St SUT1 protein was detectable in SUT1 antisense plants, whereas constitutively inhibited antisense plants showed reduction only of the monomeric form. The role of redox control of sucrose transport in plants is discussed. PMID:18790827

Krügel, Undine; Veenhoff, Liesbeth M.; Langbein, Jennifer; Wiederhold, Elena; Liesche, Johannes; Friedrich, Thomas; Grimm, Bernhard; Martinoia, Enrico; Poolman, Bert; Kühn, Christina



Comprehensive Mutational Analysis of Sucrose-Metabolizing Pathways in Streptococcus mutans Reveals Novel Roles for the Sucrose Phosphotransferase System Permease  

PubMed Central

Sucrose is perhaps the most efficient carbohydrate for the promotion of dental caries in humans, and the primary caries pathogen Streptococcus mutans encodes multiple enzymes involved in the metabolism of this disaccharide. Here, we engineered a series of mutants lacking individual or combinations of sucrolytic pathways to understand the control of sucrose catabolism and to determine whether as-yet-undisclosed pathways for sucrose utilization were present in S. mutans. Growth phenotypes indicated that gtfBCD (encoding glucan exopolysaccharide synthases), ftf (encoding the fructan exopolysaccharide synthase), and the scrAB pathway (sugar-phosphotransferase system [PTS] permease and sucrose-6-PO4 hydrolase) constitute the majority of the sucrose-catabolizing activity; however, mutations in any one of these genes alone did not affect planktonic growth on sucrose. The multiple-sugar metabolism pathway (msm) contributed minimally to growth on sucrose. Notably, a mutant lacking gtfBC, which cannot produce water-insoluble glucan, displayed improved planktonic growth on sucrose. Meanwhile, loss of scrA led to growth stimulation on fructooligosaccharides, due in large part to increased expression of the fruAB (fructanase) operon. Using the LevQRST four-component signal transduction system as a model for carbohydrate-dependent gene expression in strains lacking extracellular sucrases, a PlevD-cat (EIIALev) reporter was activated by pulsing with sucrose. Interestingly, ScrA was required for activation of levD expression by sucrose through components of the LevQRST complex, but not for activation by the cognate LevQRST sugars fructose or mannose. Sucrose-dependent catabolite repression was also evident in strains containing an intact sucrose PTS. Collectively, these results reveal a novel regulatory circuitry for the control of sucrose catabolism, with a central role for ScrA. PMID:23222725

Zeng, Lin



CO 2 exchange and structural organization of chloroplasts under hypothermia in potato plants transformed with a gene for yeast invertase  

Microsoft Academic Search

Growth, CO2 exchange, and the ultrastructure of chloroplasts were investigated in the leaves of potato plants (Solanum tuberosum L., cv. Désirée) of wild type and transformed with a gene for yeast invertase under the control of patatin class I B33 promoter (for apoplastic enzyme) grown in vitro on the Murashige and Skoog medium supplemented with 2% sucrose. At a temperature

A. N. Deryabin; M. S. Sin’kevich; S. V. Klimov; N. V. Astakhova; T. I. Trunova



Effect of salt on the response of birds to sucrose  

USGS Publications Warehouse

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.

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



A solvent-free synthesis of sucrose polyesters  

Microsoft Academic Search

A solvent-free reaction system is described for making sucrose polyesters (SPE) by interesterification of sucrose and long\\u000a chain fatty acid methyl esters. The process avoids the usual toxic solvents by using a novel two-stage reaction sequence.\\u000a In the first stage a 3:1 mole ratio of methyl esters to sucrose is reacted in the presence of potassium soaps to form a

George P. Rizzi; Harry M. Taylor



Use of sucrose as a treatment for infant colic  

PubMed Central

Accepted 5 November 1996? AIMS—To examine if sucrose has an analgesic effect on infant colic.?METHODS—Nineteen infants with typical infant colic were given 2 ml of 12% sucrose or distilled water when crying, in a double blind double crossover study. The effect was measured by parents' score.?RESULTS—Twelve improved specifically on sucrose and one on placebo (p < 0.01). Five showed a non-specific improvement. ?CONCLUSIONS—Sucrose has a significant ameliorating effect on infant colic.?? PMID:9166032

Markestad, T.; BELL, R



Calcium binding to S. mutans grown in the presence or absence of sucrose.  


Sucrose is the most cariogenic dietary carbohydrate because it is a substrate for insoluble extracellular polysaccharide (IEPS) production in dental biofilms, which can proportionally decrease bacterial density and, consequently, the number of biofilm calcium (Ca) binding sites. Ca bound to bacterial cell walls can be released into the biofilm fluid during a cariogenic challenge, reducing the driving force for mineral dissolution provoked by the pH drop. Thus, we investigated the effect of an IEPS-rich extracellular matrix on bacterial Ca binding after treatment with Ca solutions. Streptococcus mutans Ingbritt 1600 was cultivated in culture broths supplemented with 1.0% sucrose or 0.5% glucose + 0.5% fructose. The IEPS concentration in bacterial pellets was determined after alkaline extraction. Bacterial pellets were treated with 1 mM or 10 mM Ca++ solutions at 37ºC for 10 to 60 min. Ca binding to bacterial pellets, determined after acid extraction using the Arsenazo III reagent, was fast and concentration dependent. Although the IEPS concentration was approximately ten times higher in bacterial pellets cultivated in sucrose as compared to its monossaccharides, bound Ca concentration after Ca treatment was similar in both conditions. These results suggest that IEPS may not influence the amount of Ca bound to reservoirs of dental biofilms. PMID:22473343

Leitão, Tarcísio Jorge; Tenuta, Livia Maria Andaló; Ishi, Guilherme; Cury, Jaime Aparecido



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


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

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



Drought induces fructan synthesis and 1SST (sucrose: sucrose fructosyltransferase) in roots and leaves of chicory seedlings ( Cichorium intybus L.)  

Microsoft Academic Search

.  ?Seeds of Cichorium intybus L. var. foliosum cv. Flash were sown in acid-washed vermiculite and grown in a controlled-environment growth chamber. After 1 month of growth,\\u000a plantlets did not contain sucrose:sucrose 1-fructosyltransferase (1-SST), the key enzyme in fructan biosynthesis. No fructan\\u000a could be observed. Some of the plants were submitted to drought for 2 weeks. Glucose, fructose and sucrose concentrations

Joke De Roover; Kathleen Vandenbranden; André Van Laere; Wim Van den Ende



A 62-kD sucrose binding protein is expressed and localized in tissues actively engaged in sucrose transport.  

PubMed Central

Sucrose transport from the apoplasm, across the plasma membrane, and into the symplast is critical for growth and development in most plant species. Phloem loading, the process of transporting sucrose against a concentration gradient into the phloem, is an essential first step in long-distance transport of sucrose and carbon partitioning. We report here that a soybean 62-kD sucrose binding protein is associated with the plasma membrane of several cell types engaged in sucrose transport, including the mesophyll cells of young sink leaves, the companion cells of mature phloem, and the cells of the developing cotyledons. Furthermore, the temporal expression of the gene and the accumulation pattern of the protein closely parallel the rate of sucrose uptake in the cotyledon. Molecular cloning and sequence analysis of a full-length cDNA for this 62-kD sucrose binding protein indicated that the protein is not an invertase, contains a 29-amino acid leader peptide that is absent from the mature protein, and is not an integral membrane protein. We conclude that the 62-kD sucrose binding protein is involved in sucrose transport, but is not performing this function independently. PMID:1467654

Grimes, H D; Overvoorde, P J; Ripp, K; Franceschi, V R; Hitz, W D



Compartmentation of sucrose during radial transfer in mature sorghum culm  

PubMed Central

Background The sucrose that accumulates in the culm of sorghum (Sorghum bicolor (L.) Moench) and other large tropical andropogonoid grasses can be of commercial value, and can buffer assimilate supply during development. Previous study conducted with intact plants showed that sucrose can be radially transferred to the intracellular compartment of mature ripening sorghum internode without being hydrolysed. In this study, culm-infused radiolabelled sucrose was traced between cellular compartments and among related metabolites to determine if the compartmental path of sucrose during radial transfer in culm tissue was symplasmic or included an apoplasmic step. This transfer path was evaluated for elongating and ripening culm tissue of intact plants of two semidwarf grain sorghums. The metabolic path in elongating internode tissue was also evaluated. Results On the day after culm infusion of the tracer sucrose, the specific radioactivity of sucrose recovered from the intracellular compartment of growing axillary-branch tissue was greater (nearly twice) than that in the free space, indicating that sucrose was preferentially transferred through symplasmic routes. In contrast, the sucrose specific radioactivity in the intracellular compartment of the mature (ripening) culm tissue was probably less (about 3/4's) than that in free space indicating that sucrose was preferentially transferred through routes that included an apoplasmic step. In growing internodes of the axillary branch of sorghum, the tritium label initially provided in the fructose moiety of sucrose molecules was largely (81%) recovered in the fructose moiety, indicating that a large portion of sucrose molecules is not hydrolysed and resynthesized during radial transfer. Conclusion During radial transfer of sucrose in ripening internodes of intact sorghum plants, much of the sucrose is transferred intact (without hydrolysis and resynthesis) and primarily through a path that includes an apoplasmic step. In contrast, much of the sucrose is transferred through a symplasmic path in growing internode (axillary branch) tissue. These results contrast with the probable symplasmic path in mature culm of the closely related species, sugarcane. Phylogenetic variability exists in the compartmental path of radial transfer of sucrose in culms of the andropogonoid grasses. PMID:17584916

Tarpley, Lee; Vietor, Donald M



Yeasts: Neglected Pathogens  

Microsoft Academic Search

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

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



Mitochondrial assembly in yeast  

Microsoft Academic Search

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

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



Mitochondrial metabolism and stress response of yeast: Applications in fermentation technologies.  


Mitochondria are sites of oxidative respiration. During sake brewing, sake yeasts are exposed to long periods of hypoxia; the structure, role, and metabolism of mitochondria of sake yeasts have not been studied in detail. It was first elucidated that the mitochondrial structure of sake yeast transforms from filamentous to dotted structure during sake brewing, which affects malate metabolism. Based on the information of yeast mitochondria during sake brewing, practical technologies have been developed; (i) breeding pyruvate-underproducing sake yeast by the isolation of a mutant resistant to an inhibitor of mitochondrial pyruvate transport; and (ii) modifying malate and succinate production by manipulating mitochondrial activity. During the bread-making process, baker's yeast cells are exposed to a variety of baking-associated stresses, such as freeze-thaw, air-drying, and high sucrose concentrations. These treatments induce oxidative stress generating reactive oxygen species due to mitochondrial damage. A novel metabolism of proline and arginine catalyzed by N-acetyltransferase Mpr1 in the mitochondria eventually leads to synthesis of nitric oxide, which confers oxidative stress tolerance on yeast cells. The enhancement of proline and arginine metabolism could be promising for breeding novel baker's yeast strains that are tolerant to multiple baking-associated stresses. These new and practical methods provide approaches to improve the processes in the field of industrial fermentation technologies. PMID:24210052

Kitagaki, Hiroshi; Takagi, Hiroshi



Prions in Yeast  

PubMed Central

The concept of a prion as an infectious self-propagating protein isoform was initially proposed to explain certain mammalian diseases. It is now clear that yeast also has heritable elements transmitted via protein. Indeed, the “protein only” model of prion transmission was first proven using a yeast prion. Typically, known prions are ordered cross-? aggregates (amyloids). Recently, there has been an explosion in the number of recognized prions in yeast. Yeast continues to lead the way in understanding cellular control of prion propagation, prion structure, mechanisms of de novo prion formation, specificity of prion transmission, and the biological roles of prions. This review summarizes what has been learned from yeast prions. PMID:22879407

Liebman, Susan W.; Chernoff, Yury O.



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

E-print Network

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

Haarslev, Volker


Origin of Axon Membrane Hyperpolarization under Sucrose-Gap  

PubMed Central

One of the disadvantages of the sucrose-gap method for measuring membrane potentials with extracellular electrodes is a membrane hyperpolarization of the order of 30 to 60 mv, as compared with the resting potential obtained with intracellular microelectrodes in the absence of a sucrose-gap. In the present study the contribution of the sucrose-sea water junction potential to this hyperpolarization effect has been evaluated by comparing the effects on the resting potential of several anion and cation substitutions in the sea water bathing the lobster giant axon under sucrose-gap. Measurements with microelectrodes demonstrate a significant liquid junction potential between sucrose and standard artificial sea water. The value of this liquid junction potential as well as the measured resting membrane potential varies as a function of the anions and cations substituted in the sea water. Both the liquid junction potential and the sucrose-gap-induced hyperpolarization can be eliminated by using a low mobility anion to replace most of the chloride in sea water while the normal cation content remains unchanged. These data provide evidence that loop currents at the sucrose-sea water-axon junctions are at least partly responsible for membrane hyperpolarization under a sucrose gap. PMID:19210970

Blaustein, M. P.; Goldman, D. E.



Differential scanning calorimetric investigations of naturally dehydrated aqueous sucrose solutions  

Microsoft Academic Search

Differential scanning calorimetric investigations have been conducted on sucrose solutions for temperatures Tsucrose concentration range 74 < c < 97. A novel method is adopted for sample preparation. For c > 92, the room temperature phase is amorphous, as indicated by its x-ray diffraction pattern. A melting transition is reported for the first time for these

A. S. Paranjpe



Temperature dependence of water activity in aqueous solutions of sucrose  

Microsoft Academic Search

A comprehensive experimental data analysis was performed to evaluate the effect of temperature on the water activity coefficient and selected excess thermodynamic functions for aqueous solutions of sucrose. A four-suffix Margules equation with temperature-dependent parameters was used to fit thermodynamic data such as the vapor pressure, boiling point, osmotic coefficient, freezing point, sucrose solubility, heat of dilution and specific heat

Maciej Starzak; Mohamed Mathlouthi



Sucrose transporter1 functions in phloem loading in maize leaves  

PubMed Central

In most plants, sucrose is exported from source leaves to carbon-importing sink tissues to sustain their growth and metabolism. Apoplastic phloem-loading species require sucrose transporters (SUTs) to transport sucrose into the phloem. In many dicot plants, genetic and biochemical evidence has established that SUT1-type proteins function in phloem loading. However, the role of SUT1 in phloem loading in monocot plants is not clear since the rice (Oryza sativa) and sugarcane (Saccharum hybrid) SUT1 orthologues do not appear to function in phloem loading of sucrose. A SUT1 gene was previously cloned from maize (Zea mays) and shown to have expression and biochemical activity consistent with a hypothesized role in phloem loading. To determine the biological function of SUT1 in maize, a sut1 mutant was isolated and characterized. sut1 mutant plants hyperaccumulate carbohydrates in mature leaves and display leaf chlorosis with premature senescence. In addition, sut1 mutants have greatly reduced stature, altered biomass partitioning, delayed flowering, and stunted tassel development. Cold-girdling wild-type leaves to block phloem transport phenocopied the sut1 mutants, supporting a role for maize SUT1 in sucrose export. Furthermore, application of 14C-sucrose to abraded sut1 mutant and wild-type leaves showed that sucrose export was greatly diminished in sut1 mutants compared with wild type. Collectively, these data demonstrate that SUT1 is crucial for efficient phloem loading of sucrose in maize leaves. PMID:19181865

Slewinski, Thomas L.; Meeley, Robert; Braun, David M.



Sucrose Cushion Tucson Marine Phage Lab Page 1 of 4  

E-print Network

Sucrose Cushion B. Poulos Tucson Marine Phage Lab Page 1 of 4 Purifying Viruses Using Sucrose., & Sullivan, M. B. (2012). Evaluation of methods to concentrate and purify ocean virus communities through tubes with SM buffer or sterile water. The SW 40 tubes hold 12 ml total

Sullivan, Matthew B.


Comparative Sucrose Responsiveness in Apis mellifera and A. cerana Foragers  

PubMed Central

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

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



A study of ethanol tolerance in yeast.  


The ethanol tolerance of yeast and other microorganisms has remained a controversial area despite the many years of study. The complex inhibition mechanism of ethanol and the lack of a universally accepted definition and method to measure ethanol tolerance have been prime reasons for the controversy. A number of factors such as plasma membrane composition, media composition, mode of substrate feeding, osmotic pressure, temperature, intracellular ethanol accumulation, and byproduct formation have been shown to influence the ethanol tolerance of yeast. Media composition was found to have a profound effect upon the ability of a yeast strain to ferment concentrated substrates (high osmotic pressure) and to ferment at higher temperatures. Supplementation with peptone-yeast extract, magnesium, or potassium salts has a significant and positive effect upon overall fermentation rates. An intracellular accumulation of ethanol was observed during the early stages of fermentation. As fermentation proceeds, the intracellular and extracellular ethanol concentrations become similar. In addition, increases in osmotic pressure are associated with increased intracellular accumulation of ethanol. However, it was observed that nutrient limitation, not increased intracellular accumulation of ethanol, is responsible to some extent for the decreases in growth and fermentation activity of yeast cells at higher osmotic pressure and temperature. PMID:2178780

D'Amore, T; Panchal, C J; Russell, I; Stewart, G G



Production of Extracellular and Total Invertase by Candida utilis, Saccharomyces cerevisiae, and Other Yeasts  

PubMed Central

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

Dworschack, Robert G.; Wickerham, Lynferd J.



Turgor regulation of sucrose transport in sugar beet taproot tissue.  


Sink tissues that store osmotically active compounds must osmoregulate to prevent excessively high turgor. The ability to regulate turgor may be related to membrane transport of solutes and thus sink strength. To study this possibility, the kinetics of sugar uptake were determined in sugar beet (Beta vulgaris L.) taproot tissue discs over a range of cell turgors. Sucrose uptake followed biphasic kinetics with a high affinity saturating component below 20 millimolar and a low affinity linear component at higher concentrations. Glucose uptake exhibited only simple saturation type kinetics. The high affinity saturating component of sucrose and glucose uptake was inhibited by increasing cell turgor (decreasing external mannitol concentrations). The inhibition was evident as a decrease in V(max) but no effect on K(m). Sucrose uptake by tissue equilibrated in dilute buffer exhibited no saturating component. Ethylene glycol, a permeant osmoticum, had no effect on uptake kinetics, suggesting that the effect was due to changes in cell turgor and not due to decreased water potential per se. p-(Chloromercuri)benzene sulfonic acid (PCMBS) inhibited sucrose uptake at low but not high cell turgor. High cell turgor caused the tissue to become generally leaky to potassium, sucrose, amino acids, and reducing sugars. PCMBS had no effect on sucrose leakage, an indication that the turgor-induced leakage of sucrose was not via back flow through the carrier. The ability of the tissue to acidify the external media was turgor dependent with an optimum at 300 kilopascals. Acidification was sharply reduced at cell turgors above or below the optimum. The results suggest that the secondary transport of sucrose is reduced at high turgor as a result of inhibition of the plasma membrane ATPase. This inhibition of ATPase activity would explain the reduced V(max) and leakiness to low molecular weight solutes. Cell turgor is an important regulator of sucrose uptake in this tissue and thus may be an important determinant of sink strength in tissues that store sucrose. PMID:16664841

Wyse, R E; Zamski, E; Tomos, A D



Multisite phosphorylation of spinach leaf sucrose-phosphate synthase  

SciTech Connect

Spinach leaf sucrose-phosphate synthase is phosphorylated both in vivo and in vitro on serine residues. Phosphorylation of SPS in vivo yields twelve major phosphopeptides after a tryptic digest and two dimensional mapping. The in vivo labeling of three of these SPS P-peptides is reduced in illuminated leaves where the extracted enzyme is activated relative to that of dark leaves. Two of these inhibitory sites are phosphorylated as well when SPS is inactivated in vitro using ({sup 32}P)ATP. In vivo phosphorylation of two other sites is enhanced during mannose feeding of the leaves (in light or dark) which produces the highest activation state of SPS. Overall, the results confirm that light-dark regulation of SPS activity occurs as a result of regulatory seryl-phosphorylation and involves a balance between phosphorylation of sites which inhibit or stimulate activity. Regulation of the SPS protein kinase that inhibits activity is relatively unaffected by phosphate but inhibited by G1c 6-P (IC{sub 50}{approx}5 mM), which may explain the control of SPS activation state by light-dark signals.

Huber, J.L.; Huber, S.C. (North Carolina State Univ., Raleigh (USA))



Yeast Proteome Analysis  

NASA Astrophysics Data System (ADS)

Yeast organisms, and specifically Saccharomyces cerevisiae, have become model systems for many aspects in fundamental and applied research. Consistently, many papers have been published applying proteome techniques to study these organisms. The review will give an overview on the proteome research performed on yeast systems so far; however, due to the large number of publications, only selected reports can be cited neglecting many more interesting ones in the interest of space. The review will focus on research involving mass spectrom-etry as a basic proteome technique, although many more approaches are relevant for the functional characterization of proteins in the cell, e.g. the yeast two-hybrid system. We will provide an overview on yeasts as models in the context of pro-teome analysis, and explain the basic techniques currently applied in proteome approaches. The main part of the review will deal with a survey on the current status of proteomic studies in yeasts. In a first part of this chapter, we will deal with the currently available proteome maps of yeasts, and in the following part we will discuss studies dealing with fundamental aspects, but also mention proteome studies related to applied microbiology. Finally, we will envisage future perspectives of the proteome technology for studying yeasts, and draw major conclusion on the current status reached in this field of functional genomics.

Matros, Andrea; Mock, Hans-Peter


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


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


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

Yadav, Umesh Prasad; Ivakov, Alexander; Feil, Regina; Duan, Guang You; Walther, Dirk; Giavalisco, Patrick; Piques, Maria; Carillo, Petronia; Hubberten, Hans-Michael; Stitt, Mark; Lunn, John Edward



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

PubMed Central

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

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



[Penicillium-inhibiting yeasts].  


The objective of this work was to establish the in vitro and in vivo inhibition of post-harvest pathogenic moulds by yeasts in order to make a biocontrol product. Post-harvest pathogenic moulds Penicillium digitatum, P. italicum, P. ulaiense, Phyllosticta sp., Galactomyces geotrichum and yeasts belonging to genera Brettanomyces, Candida, Cryptococcus, Kloeckera, Pichia, Rhodotorula were isolated from citrus fruits. Some yeasts strains were also isolated from other sources. The yeasts were identified by their macro and micro-morphology and physiological tests. The in vitro and in vivo activities against P. digitatum or P. ulaiense were different. Candida cantarellii and one strain of Pichia subpelliculosa produced a significant reduction of the lesion area caused by the pathogenic moulds P. digitatum and P. ulaiense, and could be used in a biocontrol product formulation. PMID:15786872

Benítez Ahrendts, M R; Carrillo, L



RNAi in budding yeast.  


RNA interference (RNAi), a gene-silencing pathway triggered by double-stranded RNA, is conserved in diverse eukaryotic species but has been lost in the model budding yeast Saccharomyces cerevisiae. Here, we show that RNAi is present in other budding yeast species, including Saccharomyces castellii and Candida albicans. These species use noncanonical Dicer proteins to generate small interfering RNAs, which mostly correspond to transposable elements and Y' subtelomeric repeats. In S. castellii, RNAi mutants are viable but have excess Y' messenger RNA levels. In S. cerevisiae, introducing Dicer and Argonaute of S. castellii restores RNAi, and the reconstituted pathway silences endogenous retrotransposons. These results identify a previously unknown class of Dicer proteins, bring the tool of RNAi to the study of budding yeasts, and bring the tools of budding yeast to the study of RNAi. PMID:19745116

Drinnenberg, Ines A; Weinberg, David E; Xie, Kathleen T; Mower, Jeffrey P; Wolfe, Kenneth H; Fink, Gerald R; Bartel, David P



RNAi in Budding Yeast  

E-print Network

RNA interference (RNAi), a gene-silencing pathway triggered by double-stranded RNA, is conserved in diverse eukaryotic species but has been lost in the model budding yeast Saccharomyces cerevisiae. Here, we show that RNAi ...

Drinnenberg, Ines A.


Nitrile Metabolizing Yeasts  

NASA Astrophysics Data System (ADS)

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.

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


Structural determinants of product specificity of sucrose isomerases.  


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

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



Identification and characterization of the three homeologues of a new sucrose transporter in hexaploid wheat (Triticum aestivum L.)  

PubMed Central

Background Sucrose transporters (SUTs) play important roles in regulating the translocation of assimilates from source to sink tissues. Identification and characterization of new SUTs in economically important crops such as wheat provide insights into their role in determining seed yield. To date, however, only one SUT of wheat has been reported and functionally characterized. The present study reports the isolation and characterization of a new SUT, designated as TaSUT2, and its homeologues (TaSUT2A, TaSUT2B and TaSUT2D) in hexaploid wheat (Triticum aestivum L.). Results TaSUT2A and TaSUT2B genes each encode a protein with 506 amino acids, whereas TaSUT2D encodes a protein of 508 amino acids. The molecular mass of these proteins is predicted to be?~?54 kDA. Topological analysis of the amino acid sequences of the three homeologues revealed that they contain 12 transmembrane spanning helices, which are described as distinct characteristic features of glycoside-pentoside-hexuronide cation symporter family that includes all known plant SUTs, and a histidine residue that appears to be localized at and associated conformationally with the sucrose binding site. Yeast SUSY7/ura3 strain cells transformed with TaSUT2A, TaSUT2B and TaSUT2D were able to uptake sucrose and grow on a medium containing sucrose as a sole source of carbon; however, our subcellular localization study with plant cells revealed that TaSUT2 is localized to the tonoplast. The expression of TaSUT2 was detected in the source, including flag leaf blade, flag leaf sheath, peduncle, glumes, palea and lemma, and sink (seed) tissues. The relative contributions of the three genomes of wheat to the total expression of TaSUT2 appear to differ with tissues and developmental stages. At the cellular level, TaSUT2 is expressed mainly in the vein of developing seeds and subepidermal mesophyll cells of the leaf blade. Conclusion This study demonstrated that TaSUT2 is a new wheat SUT protein. Given that TaSUT2 is localized to the tonoplast and sucrose is temporarily stored in the vacuoles of both source and sink tissues, our data imply that TaSUT2 is involved in the intracellular partitioning of sucrose, particularly between the vacuole and cytoplasm. PMID:24237613



Medium optimization for glucoamylase production by a yeast, Pichia subpelliculosa ABWF-64, in submerged cultivation  

Microsoft Academic Search

An amylolytic yeast strain Pichia subpelliculosawas shown to produce glucoamylase in submerged cultivation. The yeast strain produced the enzyme optimally at 30 °C and pH 5.6 in shake flasks agitated at 200 rev min-1 in the optimized glucoamylase production medium containing 1% starch, 0.2% yeast extract, 0.4% K2HPO4, 0.035% NaCl and 0.1% MgCl2. Maximum enzyme production was attained during early

Sanjeev Kumar; T. Satyanarayana



Effect of CO2 concentration on photorespiration, sucrose synthesis, and carbon transport in C3 and C4 plants  

Microsoft Academic Search

The synthesis of sucrose from the glycolate pathway was investigated in relation to the carbon transportation at different CO2 concentrations in the air. Tomato and maize plants were fed with CO2 in the light in an assimilation chamber containing 90, 220, 840, and 2,290 ppm of CO2. The distribution of C in the leaf extract with 80% ethanol, the leaf

Minoru Yamauchi; Yoshio Yamada



Determination of Volumetric Coefficients of Thermal Expansion in Alcoholic Beverages and Aqueous Ethanol–Sucrose Mixtures by Differential Volume Measurements  

Microsoft Academic Search

The volumetric coefficient of thermal expansion (CTE) of diverse alcoholic beverages and aqueous ethanol–sucrose mixtures\\u000a was calculated by a simple experiment in the temperature range of 5–30°C at atmospheric pressure. The temperature and volume\\u000a corresponding changes were measured using a basic device as a dilatometer type. Alcohol degree, titratable acidity, volumetric\\u000a mass, total dry extract, reducing sugars, total polyphenol index,

Francisco Espejo; Sandra Armada


The effect of milk and sucrose consumption on caries in 6-to-11-year-old Italian schoolchildren  

Microsoft Academic Search

The effect of milk on dental caries was studied on a sample of 6-to-11-year-old Italian schoolchildren. The daily amount of milk consumed and the frequency of consumption of sucrose-containing foods were obtained by a 24-hour dietary diary. In the subsequent oral examination, the level of visible plaque and the number of decayed, extracted and filled teeth (both primary and permanent)

Stefano Petti; Roberto Simonetti; Adele Simonetti D'Arca



Fast simultaneous analysis of caffeine, trigonelline, nicotinic acid and sucrose in coffee by liquid chromatography–mass spectrometry  

Microsoft Academic Search

A rapid liquid chromatography–mass spectrometry method for the simultaneous quantification of caffeine, trigonelline, nicotinic acid and sucrose in coffee was developed and validated. The method involved extraction with hot water, clarification with basic lead acetate and membrane filtration, followed by chromatographic separation using a Spherisorb® S5 ODS2, 5?m chromatographic column and gradient elution with 0.3% aqueous formic acid\\/methanol at a

Daniel Perrone; Carmen Marino Donangelo; Adriana Farah



Amide-linked N-methacryloyl sucrose containing polymers.  


1',2,3,3',4,4',6-Hepta-O-benzyl-6'-N-methacryloyl-6'-deoxysucrose 1, 6'-deoxy-6'-N-methacryloyloxyethylureido sucrose 2 and 6,6'-dideoxy-6,6'-N-dimethacryloyloxyethylureido sucrose 3 have been homo-polymerized and copolymerized with styrene by a free radical process, yielding polymer materials with pendant sucrose moieties, attached to the polymer backbone via amide linkages. The results demonstrated that varying the structural features of the monomers, greatly affected the thermal and rheological properties of the polymers. The polymer materials obtained have been characterized by NMR, MALDI-TOF, DSC, AFM and EWC (equilibrium water content). The efficient synthesis of the three novel, regioisomerically pure, N-methacryloylamide sucrose-containing monomers (1, 2 and 3) have been described. PMID:24906726

Petrova, Krasimira T; Potewar, Taterao M; Ascenso, Osvaldo S; Barros, M Teresa



Sucrose responsiveness, learning success, and task specialization in ants.  


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, behavioral specialization, and appetitive olfactory learning in ants, including reproductive castes. We show that castes of the ant Camponotus aethiops differ in their responsiveness to sucrose and in their learning success in olfactory conditioning experiments in which sucrose is used as reward. Olfactory learning was better in foragers than in nurses, in agreement with their higher sucrose responsiveness. Interindividual variation in stimulus responsiveness and in learning may be, therefore, a crucial factor for division of labor in social insects. PMID:23860601

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



Magnetic birefringence of iron oxyhydroxide nanoparticles stabilised by sucrose  

Microsoft Academic Search

Magnetically induced optical birefringence is used to investigate pharmaceutically important iron–sucrose aqueous suspensions. XRD and TEM measurements of the system of oxyhydroxide particles stabilised by sucrose have shown that this system contains iron oxyhydroxide in the form of 2–5nm particles. The mineral form of the iron-core is suggested to be akaganeite. Anisotropy of the optical polarizability and magnetic susceptibility of

M. Koralewski; M. Pochylski; J. Gierszewski



Low frequency Raman scattering from aqueous sucrose solution  

Microsoft Academic Search

Low frequency Raman spectra of aqueous sucrose solution with percent sucrose concentration c=85 have been recorded as a function of temperature in the range 200–353 K. The line shape of the spectrum has been analysed using a model by Gochiyaev, Malinovski, Novikov and Sokolov (GMNS). Boson peak frequency ?m is found to decrease with increasing temperature from ?46cm?1 at 200

A. S. Paranjpe; S. K. Deb



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.  


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

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



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

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

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



Evidence for the Presence of a Sucrose Carrier in Immature Sugar Beet Tap Roots 1  

PubMed Central

The objectives of this work were to determine the path of phloem unloading and if a sucrose carrier was present in young sugar beet (Beta vulgaris L.) taproots. The approach was to exploit the characteristics of the sucrose analog, 1'-fluorosucrose (F-sucrose) which is a poor substrate for acid invertase but is a substrate for sucrose synthase. Ten millimolar each of [3H]sucrose and [14C]F-sucrose were applied in a 1:1 ratio to an abraded region of an attached leaf for 6 hours. [14C]F-sucrose was translocated and accumulated in the roots at a higher rate than [3H]sucrose. This was due to [3H]sucrose hydrolysis along the translocation path. Presence of [3H]hexose and [14C]F-sucrose in the root apoplast suggested apoplastic sucrose unloading with its subsequent hydrolysis. Labeled F-sucrose uptake by root tissue discs exhibited biphasic kinetics and was inhibited by unlabeled sucrose, indicating that immature roots have the ability for carrier-mediated sucrose transport from the apoplast. Collectively, in vivo and in vitro data indicate that despite sucrose hydrolysis by the wall-bound invertase, sucrose hydrolysis is not entirely essential for sugar accumulation in this tissue. PMID:16665948

Lemoine, Remi; Daie, Jaleh; Wyse, Roger



Microbial sucrose isomerases: producing organisms, genes and enzymes.  


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

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



Oxygen requirements of yeasts.  

PubMed Central

Type species of 75 yeast genera were examined for their ability to grow anaerobically in complex and mineral media. To define anaerobic conditions, we added a redox indicator, resazurin, to the media to determine low redox potentials. All strains tested were capable of fermenting glucose to ethanol in oxygen-limited shake-flask cultures, even those of species generally regarded as nonfermentative. However, only 23% of the yeast species tested grew under anaerobic conditions. A comparative study with a number of selected strains revealed that Saccharomyces cerevisiae stands out as a yeast capable of rapid growth at low redox potentials. Other yeasts, such as Torulaspora delbrueckii and Candida tropicalis, grew poorly mu max, 0.03 and 0.05 h-1, respectively) under anaerobic conditions in mineral medium supplemented with Tween 80 and ergosterol. The latter organisms grew rapidly under oxygen limitation and then displayed a high rate of alcoholic fermentation. It can be concluded that these yeasts have hitherto-unidentified oxygen requirements for growth. Images PMID:2082825

Visser, W; Scheffers, W A; Batenburg-van der Vegte, W H; van Dijken, J P



Mapping Yeast Transcriptional Networks  

PubMed Central

The term “transcriptional network” refers to the mechanism(s) that underlies coordinated expression of genes, typically involving transcription factors (TFs) binding to the promoters of multiple genes, and individual genes controlled by multiple TFs. A multitude of studies in the last two decades have aimed to map and characterize transcriptional networks in the yeast Saccharomyces cerevisiae. We review the methodologies and accomplishments of these studies, as well as challenges we now face. For most yeast TFs, data have been collected on their sequence preferences, in vivo promoter occupancy, and gene expression profiles in deletion mutants. These systematic studies have led to the identification of new regulators of numerous cellular functions and shed light on the overall organization of yeast gene regulation. However, many yeast TFs appear to be inactive under standard laboratory growth conditions, and many of the available data were collected using techniques that have since been improved. Perhaps as a consequence, comprehensive and accurate mapping among TF sequence preferences, promoter binding, and gene expression remains an open challenge. We propose that the time is ripe for renewed systematic efforts toward a complete mapping of yeast transcriptional regulatory mechanisms. PMID:24018767

Hughes, Timothy R.; de Boer, Carl G.



Yeast killer systems.  

PubMed Central

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

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



Body weight manipulation, reinforcement value and choice between sucrose and wheel running: A behavioral economic analysis  

Microsoft Academic Search

Twelve female Long-Evans rats were exposed to concurrent variable (VR) ratio schedules of sucrose and wheel-running reinforcement (Sucrose VR 10 Wheel VR 10; Sucrose VR 5 Wheel VR 20; Sucrose VR 20 Wheel VR 5) with predetermined budgets (number of responses). The allocation of lever pressing to the sucrose and wheel-running alternatives was assessed at high and low body weights.

Terry W. Belke; W. David Pierce



L-arabinose fermenting yeast  


An L-arabinose utilizing yeast strain is provided for the production of ethanol by introducing and expressing bacterial araA, araB and araD genes. L-arabinose transporters are also introduced into the yeast to enhance the uptake of arabinose. The yeast carries additional genomic mutations enabling it to consume L-arabinose, even as the only carbon source, and to produce ethanol. Methods of producing ethanol include utilizing these modified yeast strains. ##STR00001##

Zhang, Min (Lakewood, CO); Singh, Arjun (Lakewood, CO); Knoshaug, Eric (Golden, CO); Franden, Mary Ann (Centennial, CO); Jarvis, Eric (Boulder, CO); Suominen, Pirkko (Maple Grove, MN)



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


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

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



Mitochondrial assembly in yeast.  


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 of the electron transport chain. Translation and respiratory complex assembly are particularly expensive processes, together requiring around 150 of the proteins so far known. Recent developments in both areas are reviewed and approaches to the identification of novel mitochondrial proteins are discussed. PMID:10376678

Grivell, L A; Artal-Sanz, M; Hakkaart, G; de Jong, L; Nijtmans, L G; van Oosterum, K; Siep, M; van der Spek, H



Oxytocin action in the ventral tegmental area affects sucrose intake  

PubMed Central

Brain oxytocin is known to play a role in the control of food intake, and recent studies suggest that stimulation of central oxytocin receptors selectively suppresses carbohydrate intake. The specific oxytocin projection sites and receptor populations involved in this response are as yet unidentified. We hypothesized that oxytocin receptors in the ventral tegmental area (VTA) may play a role in limiting sucrose intake, because the VTA is known to influence palatable food intake. We first performed a dose response study in which we observed that intra-VTA oxytocin injection significantly suppressed intake of a 10% sucrose solution during a 30-min test session by 13.35% - 20.5% relative to vehicle treatment. Doses of intra-VTA oxytocin that suppressed sucrose intake had no effect on water intake. Next we examined the effects of two oxytocin receptor antagonists, (d(CH2)51,Tyr(Me)2,Orn8)-Oxytocin (OVT) and L-368,899. Each of these antagonists significantly increased 10% sucrose intake by 17% - 20.5% relative to vehicle when delivered directly into the VTA, at doses subthreshold for effect if injected into the cerebral ventricles. Finally, we observed that the effect of intra-VTA oxytocin to suppress 10% sucrose intake was significantly attenuated by pretreatment with L-368,899, supporting the suggestion that the VTA oxytocin treatment suppresses intake through action at oxytocin receptors. These findings support the suggestion that endogenous oxytocin action within the VTA suppresses sucrose intake. We conclude that oxytocin receptors in the VTA play a physiologic role in the control of sucrose ingestion. PMID:23548602

Mullis, Kiersten; Kay, Kristen; Williams, Diana L.



Yeast diversity of Ghanaian cocoa bean heap fermentations.  


The fermentation of the Theobroma cacao beans, involving yeasts, lactic acid bacteria, and acetic acid bacteria, has a major influence on the quality of the resulting cocoa. An assessment of the microbial community of cocoa bean heap fermentations in Ghana resulted in 91 yeast isolates. These were grouped by PCR-fingerprinting with the primer M13. Representative isolates were identified using the D1/D2 region of the large subunit rRNA gene, internal transcribed spacer sequences and partial actin gene sequences leading to the detection of 15 species. Properties of importance for cocoa bean fermentation, namely sucrose, glucose, and citrate assimilation capacity, pH-, ethanol-, and heat-tolerance, were examined for selected isolates. Pichia kudriavzevii (Issatchenkia orientalis), Saccharomyces cerevisiae, and Hanseniaspora opuntiae formed the major components of the yeast community. Hanseniaspora opuntiae was identified conclusively for the first time from cocoa fermentations. Among the less frequently encountered species, Candida carpophila, Candida orthopsilosis, Kodamaea ohmeri, Meyerozyma (Pichia) caribbica, Pichia manshurica, Saccharomycodes ludwigii, and Yamadazyma (Pichia) mexicana were not yet documented from this substrate. Hanseniaspora opuntiae was preferably growing during the earlier phase of fermentation, reflecting its tolerance to low pH and its citrate-negative phenotype, while no specific temporal distribution was recognized for P. kudriavzevii and S. cerevisiae. PMID:19473277

Daniel, Heide-Marie; Vrancken, Gino; Takrama, Jemmy F; Camu, Nicholas; De Vos, Paul; De Vuyst, Luc



Avocado oil supplementation modifies cardiovascular risk profile markers in a rat model of sucrose-induced metabolic changes.  


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

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



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

PubMed Central

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

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



Electrogenic Sucrose Transport in Developing Soybean Cotyledons 12  

PubMed Central

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

Lichtner, Francis T.; Spanswick, Roger M.



Deregulation of Sucrose-Controlled Translation of a bZIP-Type Transcription Factor Results in Sucrose Accumulation in Leaves  

PubMed Central

Sucrose is known to repress the translation of Arabidopsis thaliana AtbZIP11 transcript which encodes a protein belonging to the group of S (S - stands for small) basic region-leucine zipper (bZIP)-type transcription factor. This repression is called sucrose-induced repression of translation (SIRT). It is mediated through the sucrose-controlled upstream open reading frame (SC-uORF) found in the AtbZIP11 transcript. The SIRT is reported for 4 other genes belonging to the group of S bZIP in Arabidopsis. Tobacco tbz17 is phylogenetically closely related to AtbZIP11 and carries a putative SC-uORF in its 5?-leader region. Here we demonstrate that tbz17 exhibits SIRT mediated by its SC-uORF in a manner similar to genes belonging to the S bZIP group of the Arabidopsis genus. Furthermore, constitutive transgenic expression of tbz17 lacking its 5?-leader region containing the SC-uORF leads to production of tobacco plants with thicker leaves composed of enlarged cells with 3–4 times higher sucrose content compared to wild type plants. Our finding provides a novel strategy to generate plants with high sucrose content. PMID:22457737

Lee, Sung Shin; Yang, Seung Hwan; Zhu, XuJun; Imai, Ryozo; Takahashi, Yoshihiro; Kusano, Tomonobu



Interactions between yeast lees and wine polyphenols during simulation of wine aging. II. Analysis of desorbed polyphenol compounds from yeast lees.  


In the first part of this work, the analysis of the polyphenolic compounds remaining in the wine after different contact times with yeast lees during simulation of red wine aging was undertaken. To achieve a more precise view of the wine polyphenols adsorbed on lees during red wine aging and to establish a clear balance between adsorbed and remnant polyphenol compounds, the specific analysis of the chemical composition of the adsorbed polyphenolic compounds (condensed tannins and anthocyanins) after their partial desorbtion from yeast lees by denaturation treatments was realized in the second part of the study. The total recovery of polyphenol compounds from yeast lees was not complete, since a rather important part of the initial wine colored polyphenols, especially those with a dominant blue color component, remained strongly adsorbed on yeast lees, as monitored by color tristimulus and reflectance spectra measurements. All anthocyanins were recovered at a rather high percentage (about 62%), and it was demonstrated that they were not adsorbed in relation with their sole polarity. Very few monomeric phenolic compounds were extracted from yeast lees. With the use of drastic denaturing treatments, the total recovery of condensed tannins reached 83%. Such tannins extracted from yeast lees exhibited very high polymeric size and a rather high percentage of galloylated residues by comparison with initial wine tannins, indicating that nonpolar tannins were preferentially desorbed from yeast lees by the extraction treatments. PMID:16719509

Mazauric, Jean-Paul; Salmon, Jean-Michel



Antimicrobial activity of extractives of Solidago microglossa  

Microsoft Academic Search

The antimicrobial activity of the methanol extract from Solidago microglossa roots, essential oil from its aerial part and some isolated compounds was investigated. The oil exhibited concentration-dependent activity against all the tested bacteria and yeasts.

A. F. Morel; G. O. Dias; C. Porto; E. Simionatto; C. Z. Stuker; I. I. Dalcol



Vitrification solution without sucrose for cryopreservation in mouse blastocysts  

PubMed Central

Objective This study was designed to investigate the survival rate of vitrified mouse blastocysts depending on the presence or absence of sucrose in vitrification solution. Methods Mouse two-cell embryos were collected and cultured to blastocysts. Two vitrification solutions were prepared. The control solution was composed of 25% glycerol, 25% ethylene glycol, and 0.5 M sucrose (G25E250.5S) containing 2.5 mL glycerol, 2.5 mL ethylene glycol, 2 mL SSS, and 0.855 g sucrose in 5 mL PB1. The experimental solution was composed of 25% glycerol and 25% ethylene glycol (G25E25) and contained 2.5 mL glycerol and 2.5 mL ethylene glycol in 5 mL PB1. Artificial shrinkage was conducted by aspirating the blastocoelic fluid using an ICSI pipette. To examine the effect of sucrose in the vitrification solution on the survival rate of mouse blastocysts, the shrunken-equilibrated blastocysts were rehydrated or vitrified after being exposed to one of the two vitrification solutions. After exposure and the vitrification-thawing process, the re-expansion rate and hatching rate were evaluated after 6 hours of in vitro culture. Results The re-expansion rate of mouse blastocysts exposed to vitrification solution with and without sucrose were not different in the experimental solution (without sucrose) (98%) and the control solution (with sucrose) (92%) (p>0.05). The hatching rate was higher in the experimental solution (95%) than in the control solution (88%), but did not differ across two treatments (p>0.05). The re-expansion rate of mouse blastocysts vitrified in the control solution was 92% and 94%, respectively (p>0.05), and the hatching rate was higher in the experimental solution (90%) than in the control solution (74%) (p<0.05). Conclusion Sucrose need not be added in vitrification solution for freezing of artificially shrunken mouse blastocysts. PMID:25309855

Joo, Jong Kil; Lee, Young Ju; Jeong, Ju Eun; Kim, Seung Chul; Ko, Gyoung Rae



Sucrose: A prospering and sustainable organic raw material.  


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

Peters, Siegfried; Rose, Thomas; Moser, Matthias



Production of alcohol from Jerusalem artichokes by yeasts  

SciTech Connect

Various yeasts such as several strains of Saccharomyces diastaticus, S. cerevisiae, and Kluyveromyces fragilis were investigated for their ability to ferment the carbohydrates from Jerusalem artichokes to alcohol. Juice extracted from the artichokes was used as the fermentation substrate with and without prior hydrolysis of the carbohydrates. Fermentation was also carried out with raw artichokes without prior juice extraction. Results indicate that this raw material has good potential for fuel alcohol production by fermentation. (Refs. 15).

Duvnjak, Z.; Kosaric, N.; Kliza, S.; Hayes, D.



Extracellular Polysaccharides Produced by Yeasts and Yeast-Like Fungi  

NASA Astrophysics Data System (ADS)

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.

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


[Protein utilization of mixed feed rations in lactating pigs with reference to the essential amino acid content of the feed proteins. 2. Report. Utilization of the feed proteins in the use of soy bean extraction residue, waste liquor yeast, horse bean meal fish meal and maize gluten for a basic ration].  


Nitrogen trials were performed on lactating pigs to investigate the utilization of protein from some feeding rations. The basal ration fed to the sows consisted of ground barley+oats+flaked potatoes or ground barley+sugar beet chips. The basal ration was supplemented with a protein source. The protein feeds used were extracted soya bean meal, horse bean meal, fish meal, maize gluten and waste liquor yeast. Data for the average biological value of the dietary proteins were as follows (in the given order of protein feeds): 61%, 59%, 54%, 58% and 37%. PPV data were: 44%, 43%, 39%, 44% and 28%. The proteins of nearly all rations were deficient in lysine when compared with the range of amino acids present in the proteins of sow milk. PMID:1035091

Kracht, W; Hennig, A; Gruhn, K



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

NASA Astrophysics Data System (ADS)

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.

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



Yeast artificial chromosome cloning  

Microsoft Academic Search

Yeast artificial chromosome (YAC) cloning systems enable the cloning of DNA stretches of 50 to well over 2000 kb. This makes\\u000a it possible to study large intact regions of DNA in detail, by restriction mapping the YAC to produce a physical map and by\\u000a examining the YAC for coding sequences or genes. YACs are important for their ability to clone

Michele Ramsay



Kinetic studies on the yeast Phaffia rhodozyma.  


The yeast Phaffia rhodozyma, a promising microbial producer of the carotenoid astaxanthin, was cultivated in batch and continuous processes in an agitated and aerated fermenter using an acid peat extract based culture medium. For the accelerated growth phase, the mean specific growth rate and doubling time were found to be 0.038 h-1, and 18.24 hours, respectively. The production of astaxanthin was found to be basically growth associated, the maximum concentrations of the pigment produced in batch culture and continuous cultivation being similar. PMID:7608862

Acheampong, E A; Martin, A M



Wood impregnation of yeast lees for winemaking.  


This study develops a new method to produce more complex wines by means of an indirect diffusion of wood aromas from yeast cell-walls. An exogenous lyophilized biomass was macerated with an ethanol wood extract solution and subsequently dried. Different times were used for the adsorption of polyphenols and volatile compounds to the yeast cell-walls. The analysis of polyphenols and volatile compounds (by HPLC/DAD and GC-MS, respectively) demonstrate that the adsorption/diffusion of these compounds from the wood to the yeast takes place. Red wines were also aged with Saccharomyces cerevisiae lees that had been impregnated with wood aromas and subsequently dried. Four different types of wood were used: chestnut, cherry, acacia and oak. Large differences were observed between the woods studied with regards to their volatile and polyphenolic profiles. Sensory evaluations confirmed large differences even with short-term contact between the wines and the lees, showing that the method could be of interest for red wine making. In addition, the results demonstrate the potential of using woods other than oak in cooperage. PMID:25308662

Palomero, Felipe; Bertani, Paolo; Fernández de Simón, Brígida; Cadahía, Estrella; Benito, Santiago; Morata, Antonio; Suárez-Lepe, José A



Optimal design and operation of SMB bioreactor for sucrose inversion  

Microsoft Academic Search

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

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



[Importance of sucrose in cognitive functions: knowledge and behavior].  


Sucrose is not present in the internal milieu as such, so it is physically impossible that it may have a direct influence on cognitive functions, behaviour and knowledge. However, during the digestive process, disaccharides are released into monosaccharides, in the case of sucrose into glucose and fructose, which reach the liver via the portal vein. Finally, they go into bloodstream in the form of glucose and in some cases as very low-density lipoproteins (VLDL). Brain needs almost exclusively a constant supply of glucose from the bloodstream. Adult brain requires about 140 g of glucose per day, which represents up to a 50% of total carbohydrates consumed daily in the diet. The consumption of a food or beverage enriched with sucrose has been associated with improved mental alertness, memory, reaction time, attention and ability to solve mathematical problems, as well as a reduction in the feeling of fatigue, both in healthy individuals and patients with Alzheimer disease. An adequate nutrition of brain contributes to structural and functional integrity of neurons. It has been shown that in major mental illnesses such as schizophrenia, depression and Alzheimer's disease, nutritional deficiencies at cellular level are implicated. At present, several studies highlight the need to improve understanding of the processes involved in the deterioration of cognitive functions and mechanisms through which, the nutritive components of the diet, particularly the sucrose, may modulate such functions. PMID:23834099

Zamora Navarro, Salvador; Pérez Llamas, Francisca



Air gap membrane distillation of sucrose aqueous solutions  

Microsoft Academic Search

In this paper results obtained with air gap membrane distillation (AGMD) using sucrose aqueous solutions are shown. The role of the relevant process parameters has been investigated experimentally (the flow rate through the cell, the feed initial concentration, the type of membrane, the air gap thickness, etc.). Equations have been proposed to estimate the intermediate temperatures for the air gap

M. A. Izquierdo-Gil; M. C. Garc??a-Payo; C. Fernández-Pineda



The Trehalose Phosphotransferase System (PTS) in E. coli W Can Transport Low Levels of Sucrose that Are Sufficient to Facilitate Induction of the csc Sucrose Catabolism Operon  

PubMed Central

Plasticity in substrate acceptance is a well-characterised phenomenon for disaccharide transporters. Sucrose, a non-reducing disaccharide, is usually metabolised via either the permease-mediated chromosomally-encoded sucrose catabolism (csc) regulon or the sucrose phosphotransferase system (PTS). E. coli W is a fast-growing strain which efficiently utilises sucrose at concentrations above 1% via the csc regulon. To examine if sucrose could be metabolised via other routes, a library of transposon mutants was generated and screened on 0.2% sucrose. One mutant identified from this library had an insertion in the repressor for the regulon controlling catabolism of the disaccharide trehalose (treR). A series of mutants was constructed to elucidate the mechanism of sucrose utilization in the treR insertion strain. Analysis of these mutants provided evidence that deletion of TreR enables uptake of sucrose via TreB, an enzyme II protein required for PTS-mediated uptake of trehalose. Once inside the cell, this sucrose is not processed by the TreC hydrolase, nor is it sufficient for growth of the strain. QRT-PCR analysis showed that levels of cscA (invertase) transcript increased in the W?treR mutant relative to the wild-type strain when grown under low sucrose conditions. This result suggests that the intracellular sucrose provided by TreB can facilitate de-repression of the csc regulon, leading to increased gene expression, sucrose uptake and sucrose utilization in the treR mutant. PMID:24586369

Steen, Jennifer A.; Bohlke, Nina; Vickers, Claudia E.; Nielsen, Lars K.



Production, Characterization, and Properties of Sophorolipids from the Yeast Candida bombicola using a Low-cost Fermentative Medium  

Microsoft Academic Search

The yeast Candida bombicola produces biosurfactant with properties akin to those of sophorolipid (SL) group of compounds. In the present work, the yeast\\u000a was shown to produce 63.7 g l?1 SL when grown on a cheap fermentative medium containing sugarcane molasses, yeast extract, urea, and soybean oil. The partially\\u000a purified SL was characterized and confirmed by Fourier-transform infrared (FT-IR) spectroscopy, 1H

Achlesh Daverey; Kannan Pakshirajan



Effect of dietary intake of avocado oil and olive oil on biochemical markers of liver function in sucrose-fed rats.  


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

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



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

PubMed Central

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

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



Production of microbial levan from sucrose, sugarcane juice and beet molasses  

Microsoft Academic Search

Summary Bacillus polymyxa (NRRL-18475) produced a levan-type fructan (B, 2?6 fructofuranoside) when grown on sucrose, sugarcane juice, and sugarbeet molasses. The organism converted about 46% of the fructose moiety of sucrose to levan when grown on sucrose medium, however, the yields of levan from sugarcane juice and beet molasses were much less than sucrose solution. Such sugarcane juice and beet

Y. W. Han; M. A. Watson



Effect of activated charcoal, autoclaving and culture media on sucrose hydrolysis  

Microsoft Academic Search

The effect of activated charcoal, autoclaving and culture media on sucrose hydrolysis in tissue culture media was investigated. Activated charcoal acidified an aqueous sucrose (5%) solution and culture media by about 1 to 2 units after autoclaving. Sucrose hydrolysis in tissue culture media and\\/or aqueous sucrose (5%) solutions containing activated charcoal (buffered to pH 5.8) was dependent on both the

M. J. Pan; J. van Staden



Sucrose substitutes affect the cariogenic potential of Streptococcus mutans biofilms.  


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

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



Crystal structure of sucrose phosphorylase from Bifidobacterium adolescentis.  


Around 80 enzymes are implicated in the generic starch and sucrose pathways. One of these enzymes is sucrose phosphorylase, which reversibly catalyzes the conversion of sucrose and orthophosphate to d-Fructose and alpha-d-glucose 1-phosphate. Here, we present the crystal structure of sucrose phosphorylase from Bifidobacterium adolescentis (BiSP) refined at 1.77 A resolution. It represents the first 3D structure of a sucrose phosphorylase and is the first structure of a phosphate-dependent enzyme from the glycoside hydrolase family 13. The structure of BiSP is composed of the four domains A, B, B', and C. Domain A comprises the (beta/alpha)(8)-barrel common to family 13. The catalytic active-site residues (Asp192 and Glu232) are located at the tips of beta-sheets 4 and 5 in the (beta/alpha)(8)-barrel, as required for family 13 members. The topology of the B' domain disfavors oligosaccharide binding and reduces the size of the substrate access channel compared to other family 13 members, underlining the role of this domain in modulating the function of these enzymes. It is remarkable that the fold of the C domain is not observed in any other known hydrolases of family 13. BiSP was found as a homodimer in the crystal, and a dimer contact surface area of 960 A(2) per monomer was calculated. The majority of the interactions are confined to the two B domains, but interactions between the loop 8 regions of the two barrels are also observed. This results in a large cavity in the dimer, including the entrance to the two active sites. PMID:14756551

Sprogøe, Desiree; van den Broek, Lambertus A M; Mirza, Osman; Kastrup, Jette S; Voragen, Alphons G J; Gajhede, Michael; Skov, Lars K



21 CFR 172.896 - Dried yeasts.  

...FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.896 Dried yeasts. Dried yeast (Saccharomyces cerevisiae and Saccharomyces fragilis ) and dried torula yeast (Candida utilis ) may be safely used in food provided the...



Production of food yeast from starchy substrates  

Microsoft Academic Search

Fifteen yeast strains were selected for the production of food yeast from starchy substrates. From comparison with the amylolytic yeasts, a strain of Schwanniomyces castellii was selected and its characteristics are described.

A. Touzi; J. P. Prebois; G. Moulin; F. Deschamps; P. Galzy



Plant RNA processing: soybean pre-mRNA in a pea cell-free extract  

SciTech Connect

Using a pea cell-free extract they have demonstrated the splicing of an SP6 fusion transcript containing an intron derived from the soybean seed storage protein ..beta..-subunit gene. Intron 115 from the conglycinin gene was cloned into a SP6 vector and transcribed using standard recombinant DNA techniques. Incubation of radioactively labeled fusion transcripts in the cell-free system produced a number of products which were identified by primer extension and S1 nuclease analysis. All the products are linear RNA molecules. Lariat intermediates, similar to those found in the yeast and HeLa cell RNA processing systems, have not been detected. The linear RNA products detected in their plant in vitro processing system have various portions of the intron removed which suggests that alternative splice sites are used in processing of this plant intron due to activation of cryptic splice sites or creation of splice sites in the fusion construction. The kinetics of the reactions and parameters of the extract are similar to those determined for the HeLa cell system. Sucrose gradient analysis has demonstrated that the plant RNA products sedimented in a 30S particle, similar in size to that found for the spliceosome of the HeLa cell system.

Schuler, M.A.; Hanley, B.A.



Effect of ? 9-tetrahydrocannabinol on sucrose palatability as measured by the taste reactivity test  

Microsoft Academic Search

The taste reactivity test was employed to determine the effect of pre-treatment with ?9-Tetrahyrdrocannabinol THC on sucrose palatability. In Experiment 1, on each of 9 trials, rats were injected with THC or Vehicle prior to receiving a 5 min intraoral infusion of sucrose solution. The concentration of sucrose (2%, 10% or 32%) and the interval between the injection and the

Maegan M. Jarrett; Cheryl L. Limebeer; Linda A. Parker



Primary partitioning and storage of photosynthate in sucrose and starch in leaves of C 4 plants  

Microsoft Academic Search

A procedure involving pulse labelling of leaves with 14CO2 was developed to measure the primary (initial) partitioning of photosynthate between sucrose and starch. Partitioning of photosynthate into sucrose and starch was determined in leaves of C4 plants and compared with the patterns of storage of carbon in these products during the light period. The ratio of primary partitioning into sucrose

John E. Lunn; Marshall D. Hatch



Sweeping gas membrane distillation of sucrose aqueous solutions: Response surface modeling and optimization  

Microsoft Academic Search

Response surface methodology and desirability function approach have been applied for modeling and multi-response optimization of sweeping gas membrane distillation process used for concentration of sucrose aqueous solutions. Response surface models have been developed to predict the permeate flux and the sucrose concentration rate. The models have been statistically validated by ANOVA. The sucrose rejection factor was found to be

C. Cojocaru; M. Khayet



Reinforcement Value and Substitutability of Sucrose and Wheel Running: Implications for Activity Anorexia  

ERIC Educational Resources Information Center

Choice between sucrose and wheel-running reinforcement was assessed in two experiments. In the first experiment, ten male Wistar rats were exposed to concurrent VI 30 s VI 30 s schedules of wheel-running and sucrose reinforcement. Sucrose concentration varied across concentrations of 2.5, 7.5, and 12.5%. As concentration increased, more behavior…

Belke, Terry W.; Duncan, Ian D.; Pierce, W. David



Rats' preferences for high fructose corn syrup vs. sucrose and sugar mixtures  

Microsoft Academic Search

High fructose corn syrup (HFCS) has replaced sucrose in many food products, which has prompted research comparing these two sweeteners in rodents. The present study examined the relative palatability of HFCS and sucrose for rats, offering 11% carbohydrate solutions to match the content of common beverages for human consumption. The animals initially preferred HFCS to sucrose but after separate experience

Karen Ackroff; Anthony Sclafani



Lower glycemic response to sucrose in the diets of children with type 1 diabetes  

Microsoft Academic Search

Objective: To compare glycemic responses of isocaloric mixed meals containing 2% and 17% sucrose in children with type 1 diabetes who had fasting euglycemia.Study design: Nine children (11 to 16 years) with type 1 diabetes were randomized in a crossover design to receive 2 isocaloric diets (2% or 17% sucrose) in the Clinical Research Center. In the 2% sucrose diet,

Karyl A. Rickard; Emily S. Loghmani; Jennifer L. Cleveland; Naomi S. Fineberg; Gary R. Freidenberg



Study on the Selectivity of Benzoylation of Metal Chelates of Sucrose  

Microsoft Academic Search

A study of the selectivity of metal chelate-directed benzoylation of sucrose dianion, relative to unchelated sucrose anion, was conducted as part of a study on new synthetic approaches to the high-potency sweetener sucralose. Ionic complexes of sucrose with various metal ions were prepared in DMF and the resulting complexes reacted at low temperature with benzoic anhydride. Cobalt and manganese salts

Juan L. Navia; Richard A. Roberts; Robert E. Wingard Jr



Protein phosphorylation as a mechanism for regulation of spinach leaf sucrose-phosphate synthase activity  

SciTech Connect

Protein phosphorylation has been identified as a mechanism for the light-dark regulation of spinach sucrose-phosphate synthase (SPS) activity, previously shown to involve some type of covalent modification of the enzyme. The 120 kD subunit of SPS in extracts of light-treated leaves was labeled with {sup 32}P in the presence of ({gamma}-{sup 32}P) ATP. In this in vitro system, {sup 32}P incorporation into light-activated SPS was dependent upon ATP and magnesium concentrations as well as time, and was closely paralleled by inactivation of the enzyme. The soluble protein kinase involved in the interconversion of SPS between activated and deactivated forms may be specific for SPS as it co-purifies with SPS during partial purification of the enzyme. The kinase appears not to be calcium activated and no evidence has been obtained for metabolite control of SPS phosphorylation/inactivation.

Huber, J.L.A.; Huber, S.C. (North Carolina State Univ., Raleigh (USA))



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


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

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



Simple improvement in freeze-tolerance of bakers' yeast with poly-gamma-glutamate.  


We examined the effect of poly-gamma-glutamate (PGA) on the freeze-tolerance of four types of commercial bakers' yeast (freeze-tolerant, osmotic-tolerant, low-temperature-sensitive, and ordinary bakers' yeasts). The survival ratio of ordinary bakers' yeast cells frozen at -30 degrees C for 3 d in a medium (0.5% yeast extract, 0.5% peptone, and 2% glucose: YPD medium) was improved by adding more than 1% PGA to the medium; the survival ratio increased from about 10% to more than 70%. All PGA preparations, which differed in average molecular mass (50, 2,000, 4,000, 6,000, 8,000, and 10,000 kDa), showed a similar cryoprotecive effect on the cells. Similar results were also obtained with other types of bakers' yeast, sake yeast and beer yeast. When the four types of bakers' yeast cell were frozen at -30 degrees C for 3 d in dough supplemented with more than 1% PGA, the cells (after freezing and thawing) showed higher leavening ability than those frozen in dough without PGA, irrespective of the molecular mass of PGA. Thus, PGA appears to protect bakers' yeast from lethal freeze injury, leading to a high leavening ability after freezing and thawing. PGA did not decrease the original leavening ability of the bakers' yeast, and was not decomposed by the yeast cells. PGA suppressed the decrease in leavening ability during a prolonged fermentation time, probably because PGA adsorbed inhibitory metabolites accumulated in the dough. PGA could prove useful for improving the freeze-tolerance of bakers' yeast by its addition to dough. PMID:17046536

Yokoigawa, Kumio; Sato, Machiko; Soda, Kenji



New and emerging yeast pathogens.  

PubMed Central

The most common yeast species that act as agents of human disease are Candida albicans, Candida tropicalis, Candida glabrata, Candida parapsilosis, and Cryptococcus neoformans. The incidence of infections by other yeasts has increased during the past decade. The most evident emerging pathogens are Malassezia furfur, Trichosporon beigelii, Rhodotorula species, Hansenula anomala, Candida lusitaniae, and Candida krusei. Organisms once considered environmental contaminants or only industrially important, such as Candida utilis and Candida lipolytica, have now been implicated as agents of fungemia, onychomycosis, and systemic disease. The unusual yeasts primarily infect immunocompromised patients, newborns, and the elderly. The role of central venous catheter removal and antifungal therapy in patient management is controversial. The antibiograms of the unusual yeasts range from resistant to the most recent azoles and amphotericin B to highly susceptible to all antifungal agents. Current routine methods for yeast identification may be insufficient to identify the unusual yeasts within 2 days after isolation. The recognition of unusual yeasts as agents of sometimes life-threatening infection and their unpredictable antifungal susceptibilities increase the burden on the clinical mycology laboratory to pursue complete species identification and MIC determinations. Given the current and evolving medical practices for management of seriously ill patients, further evaluations of the clinically important data about these yeasts are needed. PMID:8665465

Hazen, K C



Object extraction Object extraction  

E-print Network

Object extraction #12;Object extraction · Extracting topographic objects from images · the main goal of aerial photogrammetry · object extraction consists of two steps · image interpretation extraction · Extracting topographic objects from images · identify all objects of a certain class · measure

Giger, Christine


Interaction of Ddc1 and RPA with single-stranded/double-stranded DNA junctions in yeast whole cell extracts: Proteolytic degradation of the large subunit of replication protein A in ddc1? strains.  


To characterize proteins that interact with single-stranded/double-stranded (ss/ds) DNA junctions in whole cell free extracts of Saccharomyces cerevisiae, we used [(32)P]-labeled photoreactive partial DNA duplexes containing a 3'-ss/ds-junction (3'-junction) or a 5'-ss/ds-junction (5'-junction). Identification of labeled proteins was achieved by MALDI-TOF mass spectrometry peptide mass fingerprinting and genetic analysis. In wild-type extract, one of the components of the Ddc1-Rad17-Mec3 complex, Ddc1, was found to be preferentially photocrosslinked at a 3'-junction. On the other hand, RPAp70, the large subunit of the replication protein A (RPA), was the predominant crosslinking product at a 5'-junction. Interestingly, ddc1? extracts did not display photocrosslinking of RPAp70 at a 5'-junction. The results show that RPAp70 crosslinked to DNA with a 5'-junction is subject to limited proteolysis in ddc1? extracts, whereas it is stable in WT, rad17?, mec3? and mec1? extracts. The degradation of the RPAp70-DNA adduct in ddc1? extract is strongly reduced in the presence of the proteasome inhibitor MG 132. We also addressed the question of the stability of free RPA, using anti-RPA antibodies. The results show that RPAp70 is also subject to proteolysis without photocrosslinking to DNA upon incubation in ddc1? extract. The data point to a novel property of Ddc1, modulating the turnover of DNA binding proteins such as RPAp70 by the proteasome. PMID:25089887

Sukhanova, Maria V; D'Herin, Claudine; Boiteux, Serge; Lavrik, Olga I



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


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

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



Measuring dendritic growth in undercooled sucrose solution droplets  

NASA Astrophysics Data System (ADS)

A simple apparatus for observing the dendritic growth in transparent solutions at high undercoolings is described. This method involves the suspension of a droplet on the junction of a thermocouple. With this method it is possible to measure the ice dendrite growth velocity and tip radius to the limit of stable dendritic growth in sucrose solutions. Good agreement was observed with previous growth velocity data. Analysis with the Lipton, Kurtz and Trivedi (LKT) dendritic growth model showed that at high undercoolings the dendritic growth in sucrose solutions becomes predominately thermally and kinetically controlled, whereas the kinetic growth becomes increasingly diffusion and viscosity limited with increasing undercooling and melt solute concentration. The results supported previously proposed changes to the LKT model to accommodate high undercoolings and changing melt diffusivity and viscosity.

Hindmarsh, J. P.; Russell, A. B.; Chen, X. D.



Roughness effect on the overall growth rate of sucrose crystals  

NASA Astrophysics Data System (ADS)

The roughness effect on crystal growth rate was investigated at 35C in a fluidized bed crystallizer and in a batch crystallizer. The crystallization of sucrose in pure aqueous solutions was the study subject. The results show that the sucrose crystals exhibit time-dependent growth rate. The overall growth rate decreased continually with time until a constant value was reached, that corresponds to a decrease of 40% considering the experiments of 13 and 63 min duration in the fluidized bed crystallizer. The decrease of the growth rates with the contact time between crystals and supersaturated solution was interpreted in terms of the increase of surfaces' roughness. According to SEM micrographs, the surface roughness increases significantly with residence time and supersaturation. The roughness appears to be the result of faulty integration of growth clusters in the crystal surface. The batch experiments show that the surface roughness acts like a strong impurity. The results were interpreted according to the Kubota-Mullin model.

Ferreira, A.; Faria, N.; Rocha, F.



Sugar signaling of fructan metabolism: New insights on protein phosphatases in sucrose-fed wheat leaves.  


Protein phosphatase type 2A (PP2A) activity is required for the sucrose induction of fructan metabolism in wheat leaves, as shown in experiments with the addition of the specific inhibitor okadaic acid (OA) together with sucrose. However, a decrease in total PP2A activity has been found along sucrose treatment. Here we analyze the effect of sucrose feeding to wheat leaves on PP2A activity profiles after Deae-Sephacel and Superose separation, in comparison with those of control leaves. The results show no evidence of changes in PP2A activity profiles as a consequence of sucrose feeding. In all, our data suggest that constitutive levels of PP2A activity may be sufficient for the sucrose-mediated induction of fructan metabolism and that general decrease of PP2A activity produced by long-term treatment with sucrose may be due to a negative feedback regulation. PMID:20220311

Martinez-Noël, Giselle A; Tognetti, Jorge A; Salerno, Graciela L; Pontis, Horacio G



Optical trapping and surgery of living yeast cells using a single laser.  


We present optical trapping and surgery of living yeast cells using two operational modes of a single laser. We used a focused laser beam operating in continuous-wave mode for noninvasive optical trapping and manipulation of single yeast cell. We verified that such operational mode of the laser does not cause any destructive effect on yeast cell wall. By changing the operation of the laser to femtosecond-pulsed mode, we show that a tightly focused beam dissects the yeast cell walls via nonlinear absorption. Lastly, using the combined technique of optical microsurgery and trapping, we demonstrate intracellular organelle extraction and manipulation from a yeast cell. The technique established here will be useful as an efficient method for both surgery and manipulation of living cells using a single laser beam. PMID:19044717

Ando, Jun; Bautista, Godofredo; Smith, Nicholas; Fujita, Katsumasa; Daria, Vincent Ricardo



Immobilized yeast bioreactor systems for continuous beer fermentation  


Two different types of immobilized yeast bioreactors were examined for continuous fermentation of high-gravity worts. One of these is a fluidized bed reactor (FBR) that employs porous glass beads for yeast immobilization. The second system is a loop reactor containing a porous silicon carbide cartridge (SCCR) for immobilizing the yeast cells. Although there was some residual fermentable sugar in the SCCR system product, nearly complete attenuation of the wort sugars was achieved in either of the systems when operated as a two-stage process. Fermentation could be completed in these systems in only half the time required for a conventional batch process. Both the systems showed similar kinetics of extract consumption, and therefore similar volumetric productivity. As compared to the batch fermentation, total fusel alcohols were lower; total esters, while variable, were generally higher. The yeast biomass production was similar to that in a conventional fermentation process. As would be expected in an accelerated fermentation system, the levels of vicinal diketones (VDKs) were higher. To remove the VDKs, the young beer was heat-treated to convert the VDK precursors and processed through a packed bed immobilized yeast bioreactor for VDK assimilation. The finished product from the FBR system was found to be quite acceptable from a flavor perspective, albeit different from the product from a conventional batch process. Significantly shortened fermentation times demonstrate the feasibility of this technology for beer production. PMID:9933520

Tata; Bower; Bromberg; Duncombe; Fehring; Lau; Ryder; Stassi



Inactivation of highly activated spinach leaf sucrose-phosphate synthase by dephosphorylation. [Spinacia oleracea  

SciTech Connect

Spinach (Spinacia oleracea L.) leaf sucrose-phosphate synthase (SPS) can be phosphorylated and inactivated in vitro with ({gamma}-{sup 32}P)ATP. Thus, it was surprising to find that SPS, extracted from leaves fed mannose in the light to highly activate the enzyme, could be inactivated in an ATP-independent manner when desalted crude extracts were preincubated at 25{degrees}C before assay. The spontaneous inactivation involved a loss in activity measured with limiting substrate concentrations in the presence of the inhibitor, Pi, without affecting maximum catalytic activity. The spontaneous inactivation was unaffected by exogenous carrier proteins and protease inhibitors, but was inhibited by inorganic phosphate, fluoride, and molybdate, suggesting that a phosphatase may be involved. Okadaic acid, a potent inhibitor of mammalian type 1 and 2A protein phosphatases, had no effect up to 5 micromolar. Inactivation was stimulated about twofold by exogenous Mg{sup 2+} and was relatively insensitive to Ca{sup 2+} and to pH over the range pH 6.5 to 8.5. Radioactive phosphate incorporated into SPS during labeling of excised leaves with ({sup 32}P)Pi (initially in the dark and then in the light with mannose) was lost with time when desalted crude extracts were incubated at 25 C, and the loss in radiolabel was substantially reduced by fluoride. These results provide direct evidence for action of an endogenous phosphatase(s) using SPS as substrate.

Huber, J.L. (North Carolina State Univ., Raleigh (United States)); Huber, S.C. (Dept. of Agriculture, Raleigh, NC (United States) North Carolina State Univ., Raleigh (United States)); Hite, D.R.C.; Outlaw, W.H. Jr. (Florida State Univ., Tallahassee (United States))



Brewer's yeast and sugarcane yeast as protein sources for dogs.  


Brewer's yeast (BY), autolysed sugarcane yeast (ASCY) and integral sugar cane yeast (ISCY) were studied in two experiments as ingredients for dog diets. In the first experiment, 28 dogs were randomly assigned to four diets; one reference diet and three test diets containing 15% of BY, ASCY or ISCY and 85% of the reference diet (as-fed basis). The digestibilities of the yeasts were calculated by the substitution method. In the second experiment, 35 dogs were randomized to five diets with similar chemical composition but different levels of sugarcane yeast inclusion (0%, 7.5% ASCY, 15% ASCY, 7.5% ISCY and 15% ISCY). In both experiments, the coefficient of total tract apparent digestibility (CTTAD) of nutrients was determined through total collection of faeces. During experiment, two additional analyses of food palatability, nitrogen balance and urea postprandial responses were performed. The data were submitted to analysis of variance, and the means were compared by orthogonal or polynomial contrasts or Tukey's test (p < 0.05). In experiment 1, CTTAD of protein was lower for both sugarcane yeasts than for BY (p = 0.012), as was metabolizable energy content (p = 0.025). In experiment 2, a linear reduction in energy digestibility with ASCY inclusion (p = 0.05) was verified. Furthermore, faecal score and DM content were reduced with ISCY inclusion (p < 0.003). No effect of yeast inclusion on nitrogen balance or postprandial urea response was found. Also, the inclusion of 7.5% of ASCY or ISCY increased diet palatability (p < 0.01). Yeasts present adequate digestibility by dogs, but its effect on faecal formation needs to be considered. No clear advantage for the use of ASCY over ISCY was found. In conclusion, we find that sugarcane yeast is suitable for inclusion in dog food and can enhance the overall palatability of the diet. PMID:24304448

Martins, M S; Sakomura, N K; Souza, D F; Filho, F O R; Gomes, M O S; Vasconcellos, R S; Carciofi, A C



Steroid hormone excretion is enhanced by sucrose feeding to rats  

SciTech Connect

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 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.

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



Transitions in Aqueous Solutions of Sucrose at Subzero Temperatures  

Microsoft Academic Search

Classical and temperature?modulated DSC methods were employed to study aqueous solutions of sucrose in the whole concentration range and the temperature interval of ?120°C to 30°C. New interpretation of experimental data based on the state diagram has shown that transitions observed at temperatures below the melting temperature of ice are glass transitions of two amorphous phases in the system—the maximally

A. Sikora; V. O. Dupanov; J. Kratochvíl; J. Záme?ník



Diffusion of Trehalose and Sucrose in Aqueous Solution  

Microsoft Academic Search

Trehalose is emerging as superior substitute for sucrose in solution as a cryoprotectant, e. g., to preserve organs destined for transplantation. We have used the proton NMR pulsed-gradient spin-echo method between T = 30 and 85 deg. C to study the self-diffusion of solvent and solute in aqueous solutions of these molecules as function of their concentration, c. We find

E. Feick; E. von Meerwall; N. Ekdawi; J. de Pablo



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


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

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



Diffusion of sucrose and dextran through agar gel membranes.  


Mass transfer limitations severely impede the performance of bioreactions involving large molecules by gel-entrapped microorganisms. This paper describes a quantitative investigation of such diffusional limitations in agar gel membranes. Sucrose and commercial dextran fractions with (weight-average) molecular weights ranging from 10,000 to 2,000,000 Da were used as standard diffusants. For all tested solutes but sucrose, the values of the agar/water partition coefficients highlighted steric hindrance at the entrance of the membrane pores. The effective diffusivity of sucrose in agar was similar to that in water. All dextran fractions, however, displayed restricted diffusion in the agar membranes. Their effective diffusivities were a decreasing function of the agar content of the gel membrane (0.5, 1.0, or 1.5% w/v). The effective diffusivity in a given membrane decreased as the molecular weight of the diffusing molecule increased. T500 (Mw = 470,000 Da) and T2000 (Mw = 1,950,000 Da) fractions were unable to diffuse through 1.0 or 1.5% agar membranes. The diffusion data did not agree with the classical (Renkin) model for a hard sphere diffusing through a cylindrical pore. These results are discussed in terms of gel and diffusant characteristics. PMID:7505595

Lebrun, L; Junter, G A



The effect of sucrose on infants during a painful procedure  

PubMed Central

Purpose The purpose of this study was to test the efficacy of treating the pain among newborn infants associated with a medical procedure with sucrose with regard to overall physiological and behavioral stability. Methods 103 newborn infants were enrolled in this study. The control group (n=63) did not receive any treatment. The experimental group (n=40) received 2 mL of 24% sucrose solution two minutes before a routine heel stick. The pain was assessed by measurements of physiological changes [e.g. pulse rate, oxygen saturation, salivary cortisol (hydrocortisone)] and behavioral changes [e.g. crying time, and the neonatal infant pain scale (NIPS) for neonates]. Results There were no differences among the groups with respect to physiological changes associated with the pain from the procedure. However, there were significant group differences in behavioral changes to the pain. In the control group, the median crying time was 13 seconds, while in the experimental group, the median crying time was 3.5 seconds (P=.000). In the control group the median NIPS score was 4, while in the experimental group the median NIPS score was 2 (P=.000). Conclusions These findings suggest that sucrose can be an effective method for the management of stress responses in infants with regard to behavior. However, this treatment had no significant physiological effects. PMID:21189976

Joung, Kyoung Hwa



Sucrose self-administration and CNS activation in the rat.  


We have previously reported that administration of insulin into the arcuate nucleus of the hypothalamus decreases motivation for sucrose, assessed by a self-administration task, in rats. Because the pattern of central nervous system (CNS) activation in association with sucrose self-administration has not been evaluated, in the present study, we measured expression of c-Fos as an index of neuronal activation. We trained rats to bar-press for sucrose, according to a fixed-ratio (FR) or progressive-ratio (PR) schedule and mapped expression of c-Fos immunoreactivity in the CNS, compared with c-Fos expression in handled controls. We observed a unique expression of c-Fos in the medial hypothalamus (the arcuate, paraventricular, retrochiasmatic, dorsomedial, and ventromedial nuclei) in association with the onset of PR performance, and expression of c-Fos in the lateral hypothalamus and the bed nucleus of stria terminalis in association with the onset of FR performance. c-Fos expression was increased in the nucleus accumbens of both FR and PR rats. Our study emphasizes the importance of both hypothalamic energy homeostasis circuitry and limbic circuitry in the performance of a food reward task. Given the role of the medial hypothalamus in regulation of energy balance, our study suggests that this circuitry may contribute to reward regulation within the larger context of energy homeostasis. PMID:21307361

Figlewicz, Dianne P; Bennett-Jay, Jennifer L; Kittleson, Sepideh; Sipols, Alfred J; Zavosh, Aryana



Susceptibility of adult mosquitoes to insecticides in aqueous sucrose baits.  


Mosquitoes characteristically feed on plant-derived carbohydrates and honeydew just after emergence and intermittently during their lives. Development of toxic baits focusing on this carbohydrate-seeking behavior may potentially contribute to localized control. In the present study, ten insecticides were fed to female Culex quinquefasciatus, Anopheles quadrimaculatus, and Aedes taeniorhynchus in a 10% sucrose solution. Active ingredients representative of five classes of insecticides (pyrethroids, phenylpyroles, pyrroles, neonicotinoids, and macrocyclic lactones) were selected for comparison with commercial formulations used to facilitate incorporation of active ingredients into aqueous sucrose solutions. Sucrose as a phagostimulant significantly enhanced mortality to toxicants. In general, the most effective active ingredients were fipronil, deltamethrin and imidacloprid, followed by spinosad, thiamethoxam, bifenthrin, permethrin, and cyfluthrin. The least effective ingredients were chlorfenapyr and ivermectin. For some of the ingredients tested, Cx. quinquefasciatus was the least susceptible species. One-day-old male Cx. quinquefasciatus were more susceptible than females; however, no differences existed between one- and seven-day-old mosquitoes. There were no differences in susceptibility between unfed and gravid ten-day-old female Cx. quinquefasciatus to bifenthrin. In conclusion, several pesticides from different classes of compounds have potential for use in development of toxic baits for mosquitoes. PMID:21635642

Allan, Sandra A




Microsoft Academic Search

The coefficient of mutual diffusion and the two coefficients of self-; diffusion of aqueous solutions of sucrose from 0 to 2.5 M were measured at 25 deg ; C. The results indicate that the self-diffusion is caused, in part, by the water -; water and sucrose - sucrose exchange, and also to the water- sucrose exchange ; which contributes, at

A. W. Adamson; R. Irani



Cool temperature hinders flux from glucose to sucrose during cellulose synthesis in secondary wall stage cotton fibers  

Microsoft Academic Search

Current knowledge about the integration of cellulose synthesis into cellular carbon metabolism and the cool temperature sensitivity of cellulose synthesis is reviewed briefly. Roles for sucrose synthase (to channel UDP-glucose to the cellulose synthase) and sucrose phosphate synthase (to recycle the fructose released by sucrose synthase to more sucrose) in secondary wall cellulose synthesis are described. Data are presented that

L. Kirt Martin; Candace H. Haigler



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

Microsoft Academic Search

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

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



RoleofSucrose Phosphate Synthase inSucrose Biosynthesis inRipening BananasandIts Relationship totheRespiratory Climacteric  

Microsoft Academic Search

During ripening ofbananas(Musa spp.(AAAgroup, Cavendish subgroup)), there isamassive conversion ofstarch tosucrose. Alsoduring ripening there isa rise inrespiration knownasthe respiratory climacteric. Inthisstudychanges incarbohydrate content, activities ofstarch andsucrosemetabolizing enzymes, andrespiration weremeasured toassesstheir potential interre- lationships. Sucrose phosphate synthase activity increased dra- matically during thefirst 4daysafter initiation ofripening by ethylene treatment. Starch concentration decreased andsucrose concentration increased during this timeperiod. Developmental changes insucrosephosphate

Natalie L. Hubbard; D. MasonPharr; C. Huber


Water, ice and sucrose behavior in frozen sucrose–protein solutions as studied by 1H NMR  

Microsoft Academic Search

This work aimed at characterizing both the spin–spin (T2) and spin–lattice (T1) relaxations of water in frozen samples. Pure water and aqueous solutions (sucrose and\\/or casein) were studied, temperatures ranging from ?13 to 20 °C. Three relaxation components could be distinguished after signal fitting. For example, the shorter spin–spin relaxation time was only observed at the frozen state and attributed to

Tiphaine Lucas; François Mariette; Sandra Dominiawsyk; Dominique Le Ray



Characteristics of Sucrose Transport and Sucrose-Induced H+ Transport on the Tonoplast of Red Beet (Beta vulgaris L.) Storage Tissue.  

PubMed Central

Sucrose-induced changes of the energization state of the red beet root (Beta vulgaris L. ssp. conditiva) vacuolar membrane were observed with the fluorescent dyes 6-chloro-9-{[4-(diethylamino)- 1-methylbutyl]-amino}-2-methoxyacridine dihydrochloride, as a pH monitor, and 9-amino-6-chloro-2-methoxyacridine (ACMA). Consequently, transient acidification of the surrounding suspension medium could be measured with a pH electrode. This signal was specific for Suc and was not seen for sorbitol, mannitol, or maltose. Sucrose-induced medium acidification was sensitive to the same inhibitors that were efficient in inhibiting sucrose transport, including the monoclonal antibodies TNP56-12 and C50-5-3. It was seen with vacuoles and vesicles energized with MgATP before sucrose was added but also with vacuoles not artificially energized previously. Using bafilomycin A1 for the inhibition of the vacuolar ATPase of vacuoles previously energized by MgATP, apparent Km values for H+ export from the vacuoles to the medium could be calculated taking into account the passive proton leak. Apparent Km values for H+ export determined from data obtained with pH measurements in the medium and with ACMA corresponded to those obtained previously for sucrose uptake. Comparing sucrose uptake rates with corresponding H+ export rates at the respective sucrose concentrations and at Km, a stoichiometry of approximately one proton per transported sucrose was estimated. PMID:12228372

Getz, H. P.; Klein, M.



Yeast Lipids Can Phase-separate into Micrometer-scale Membrane Domains*  

PubMed Central

The lipid raft concept proposes that biological membranes have the potential to form functional domains based on a selective interaction between sphingolipids and sterols. These domains seem to be involved in signal transduction and vesicular sorting of proteins and lipids. Although there is biochemical evidence for lipid raft-dependent protein and lipid sorting in the yeast Saccharomyces cerevisiae, direct evidence for an interaction between yeast sphingolipids and the yeast sterol ergosterol, resulting in membrane domain formation, is lacking. Here we show that model membranes formed from yeast total lipid extracts possess an inherent self-organization potential resulting in liquid-disordered-liquid-ordered phase coexistence at physiologically relevant temperature. Analyses of lipid extracts from mutants defective in sphingolipid metabolism as well as reconstitution of purified yeast lipids in model membranes of defined composition suggest that membrane domain formation depends on specific interactions between yeast sphingolipids and ergosterol. Taken together, these results provide a mechanistic explanation for lipid raft-dependent lipid and protein sorting in yeast. PMID:20647309

Klose, Christian; Ejsing, Christer S.; García-Sáez, Ana J.; Kaiser, Hermann-Josef; Sampaio, Julio L.; Surma, Michal A.; Shevchenko, Andrej; Schwille, Petra; Simons, Kai



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


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

Siavoshi, Farideh; Saniee, Parastoo



Production of malic and succinic acids by sugar-tolerant yeast Zygosaccharomyces rouxii  

Microsoft Academic Search

Zygosaccharomyces rouxii V19 was grown in YPG medium (yeast extract, 0.5%, peptone, 1.0%, glucose, 10%). Fermented broth was purified through a series of ion-exchange columns and ODS column and the purified sample was TMS-esterified. Malic and succinic acids were identified with GC-MS analysis. The yeast was cultivated under various cultural conditions and quantitative determination of the organic acids was carried

Ok Taing; Kazuya Taing



Properties of a pentulose-5-phosphate phosphoketolase from yeasts grown on xylose  

Microsoft Academic Search

Phosphoketolase activity from nine yeasts grown on xylose occurred with both xylulose 5-phosphate (Xu5P) and ribulose 5-phosphate (Ru5P) as substrates. With extracts from five yeasts (Candida curvata, C. famata, Lipomyces starkeyi, Rhodotorula glutinis and Pachysolen tannophilus) activity was approximately the same with either substrate; with C. boidinii, Pichia media and Yarrowia lipolytica Ru5P was the preferred substrate; and with Rhodosporidium

Colin Ratledge; Jane E. Holdsworth



Pontine and Thalamic Influences on Fluid Rewards: I. Operant Responding for Sucrose and Corn Oil  

PubMed Central

The reward strength of orosensory sucrose and corn oil was measured using fixed and progressive ratio operant schedules. Because the orosensory effects of the stimuli were of interest, Experiment 1 compared operant responses for sucrose in sham and real feeding rats. The results demonstrated that rats would work for sucrose solutions without the accompanying postingestive effects. Furthermore, the break points for high concentrations of sucrose (1.0 M or 2.0 M) were significantly higher in sham feeding rats than in real feeding controls. Experiment 2 investigated the role of the parabrachial nucleus (PBN) and of the thalamic orosensory area (TOA) in sucrose and corn oil reward. During free access, rats with PBN lesions (PBNx) licked significantly less sucrose solution than their controls, but both groups ingested a similar volume of corn oil emulsion. When an operant was imposed, these same PBNx rats failed to respond for sucrose and continued only modestly for corn oil. In contrast, the TOA lesioned rats (TOAx) showed no impairment in responding for sucrose or corn oil during either the free access or operant sessions. Furthermore, rats with TOA lesions demonstrated significantly higher break points for sucrose than did their controls. Together, the data imply that the PBN but not the TOA is critical for the perception of, or responding to the reward value of sucrose and corn oil. PMID:21703290

Liang, Nu-Chu; Freet, Christopher S.; Grigson, Patricia S; Norgren, Ralph



Scanning Electron Microscopic study of Piper betle L. leaves extract effect against Streptococcus mutans ATCC 25175  

PubMed Central

Introduction Previous studies have shown that Piper betle L. leaves extract inhibits the adherence of Streptococcus mutans to glass surface, suggesting its potential role in controlling dental plaque development. Objectives: In this study, the effect of the Piper betle L. extract towards S. mutans (with/without sucrose) using scanning electron microscopy (SEM) and on partially purified cell-associated glucosyltransferase activity were determined. Material and Methods S. mutans were allowed to adhere to glass beads suspended in 6 different Brain Heart Infusion broths [without sucrose; with sucrose; without sucrose containing the extract (2 mg mL-1 and 4 mg mL-1); with sucrose containing the extract (2 mg mL-1 and 4 mg mL-1)]. Positive control was 0.12% chlorhexidine. The glass beads were later processed for SEM viewing. Cell surface area and appearance and, cell population of S. mutans adhering to the glass beads were determined upon viewing using the SEM. The glucosyltransferase activity (with/without extract) was also determined. One- and two-way ANOVA were used accordingly. Results It was found that sucrose increased adherence and cell surface area of S. mutans (p<0.001). S. mutans adhering to 100 µm2 glass surfaces (with/without sucrose) exhibited reduced cell surface area, fluffy extracellular appearance and cell population in the presence of the Piper betle L. leaves extract. It was also found that the extract inhibited glucosyltransferase activity and its inhibition at 2.5 mg mL-1 corresponded to that of 0.12% chlorhexidine. At 4 mg mL-1 of the extract, the glucosyltransferase activity was undetectable and despite that, bacterial cells still demonstrated adherence capacity. Conclusion The SEM analysis confirmed the inhibitory effects of the Piper betle L. leaves extract towards cell adherence, cell growth and extracellular polysaccharide formation of S. mutans visually. In bacterial cell adherence, other factors besides glucosyltransferase are involved. PMID:21552715

RAHIM, Zubaidah Haji Abdul; THURAIRAJAH, Nalina



Influence of antioxidant structure on local molecular mobility in amorphous sucrose.  


The effect of the antioxidants gallic acid and methyl, propyl, and octyl gallate on the molecular mobility and hydrogen bond network in amorphous sucrose was studied. Solid amorphous sucrose films with and without the addition of antioxidants at a mole ratio of 1:5 (antioxidant/sucrose) were cast from solution onto quartz slides. Local molecular mobility from 0 to 70°C was measured using tryptophan amino acid as a luminescent probe dispersed in the films. Phosphorescence from the tryptophan probe provides spectroscopic characteristics-emission spectrum and lifetime-that are sensitive to changes in molecular mobility induced by the addition of antioxidants. Local molecular mobility detected by tryptophan increased in the following order: sucrose-octyl gallate<sucrose-propyl gallate?sucrose-methyl gallate?sucrose-gallic acid. The antioxidants also modulated the activation energy for matrix motions that quench the tryptophan phosphorescence in a structure-dependent manner. IR measurements as a function of temperature indicated that hydrogen bond strength in these amorphous films followed a rank order (sucrose-methyl gallate>sucrose-gallic acid>sucrose-propyl gallate>sucrose>sucrose-octyl gallate) that was nearly the reverse of that seen in matrix mobility. Analysis of the differential effects of the antioxidants suggests that the presence of the hydroxyl benzoyl head group increased matrix molecular mobility and hydrogen bond strength while the saturated carbon chain decreased mobility and bond strength. The influence of the carboxyl group on matrix properties was comparable to that of the formyloxy group. These results indicate that the addition of specific functional ingredients such as antioxidants may significantly affect the physical properties and consequently functional properties of amorphous edible films in ways that might condition their use. The observed changes are closely related to the chemical structure of the added species. PMID:24239605

Liang, Jun; Corradini, Maria G; Ludescher, Richard D



Expression profiling of sucrose metabolizing genes in Saccharum, Sorghum and their hybrids.  


Sucrose phosphate synthase (SPS; EC, sucrose synthase (SuSy; EC and soluble acid invertase (SAI; EC are key enzymes that regulate sucrose fluxes in sink tissues for sucrose accumulation in sugarcane and sorghum. In this study, the expression profiling of sucrose-related genes, i.e. SPS, SuSy and SAI in two sets of hybrids viz., one from a Sorghum?×?Saccharum cross and the other from a Saccharum?×?Sorghum cross, high- and low-sucrose varieties, sweet and grain sorghum lines was carried out using semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) at monthly intervals. The results indicated differential expression of the three genes in high- and low-sucrose forms. Expression of SPS and SuSy genes was high in high-sucrose varieties, Saccharum?×?Sorghum hybrids and sweet sorghum and lower in low-sucrose varieties, Sorghum?×?Saccharum hybrids and grain sorghum. SAI showed a lower expression in high-sucrose varieties, Saccharum?×?Sorghum hybrids and sweet sorghum and higher expression in low-sucrose varieties, Sorghum?×?Saccharum hybrids and the grain sorghum. This study describes the positive association of SPS and SuSy and negative association of SAI on sucrose accumulation. This is the first report of differential expression profiling of SPS, SuSy and SAI in intergeneric hybrids involving sugarcane and sorghum, which opens the possibility for production of novel hybrids with improved sucrose content and with early maturity. PMID:25119544

Ramalashmi, K; Prathima, P T; Mohanraj, K; Nair, N V



Effects of aspirin and Helicobacter pylori on the gastroduodenal mucosal permeability to sucrose.  

PubMed Central

BACKGROUND: A non-invasive marker is needed to identify patients with significant gastrointestinal injury due to non-steroidal anti-inflammatory drugs. Gastrointestinal permeability to sucrose has been suggested as such a test. AIMS: To assess the utility of sucrose permeability as a marker of gastroduodenal mucosal injury after single and multiple doses of aspirin, to identify the site of increased sucrose permeability, to explore the relation between sucrose permeability and endoscopic findings, and to evaluate whether Helicobacter pylori infection influenced gastroduodenal sucrose permeability. METHODS: After a fasting urine was obtained, 500 ml of a solution containing 100 g of sucrose was ingested. Urine was collected for five hours and assayed for sucrose by high performance liquid chromatography. Sucrose permeability was also assessed 20 minutes after ingestion of 650 mg of aspirin and eight to 12 hours after a 72 hour course of 650 mg aspirin four times a day. The site of increased permeability was identified after pyloric occlusion with a double balloon tube. RESULTS: Thirty seven healthy volunteers participated. Sucrose permeability (mean (SEM)) increased after both single (195.2 (27) mg and multiple (196.4 (31) mg) doses of aspirin compared with baseline (53.7 (10) mg; p < 0.0005). Balloon pyloric occlusion confirmed that the site of increased sucrose permeability was the stomach. The effect of aspirin on sucrose permeability was similar in those with and without H pylori infection. CONCLUSION: These results confirm the use of sucrose permeability as a marker of aspirin induced gastroduodenal mucosal injury and identify the stomach as the major site of increased permeability. H pylori infection does not seem to change gastric mucosal sucrose permeability either at baseline or after ingestion of aspirin. PMID:8977334

Rabassa, A A; Goodgame, R; Sutton, F M; Ou, C N; Rognerud, C; Graham, D Y



Yeast Metabolism Lab Mrs. Zimmerman  

E-print Network

Energy from sunlight #12;Respiration #12;Cellular Respiration C6H12O6 + 6 O2 6 CO2 + 6 H2O + energyYeast 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

Rose, Michael R.


Yeast models for amyloid disease.  


Saccharomyces cerevisiae (baker's yeast) is a well-established eukaryotic model organism, which has significantly contributed to our understanding of mechanisms that drive numerous core cellular processes in higher eukaryotes. Moreover, this has led to a greater understanding of the underlying pathobiology associated with disease in humans. This tractable model offers an abundance of analytical capabilities, including a vast array of global genetics and molecular resources that allow genome-wide screening to be carried out relatively simply and cheaply. A prime example of the versatility and potential for applying yeast technologies to explore a mammalian disease is in the development of yeast models for amyloid diseases such as Alzheimer's, Parkinson's and Huntington's. The present chapter provides a broad overview of high profile human neurodegenerative diseases that have been modelled in yeast. We focus on some of the most recent findings that have been developed through genetic and drug screening studies using yeast genomic resources. Although this relatively simple unicellular eukaryote seems far removed from relatively complex multicellular organisms such as mammals, the conserved mechanisms for how amyloid exhibits toxicity clearly underscore the value of carrying out such studies in yeast. PMID:25131588

Panaretou, Barry; Jones, Gary W



Yeasts preservation: alternatives for lyophilisation.  


The aim of the study was to compare the effect of two low-cost, low technology traditional methods for drying starter cultures with standard lyophilisation. Lyophilised yeast cultures and yeast cultures preserved in dry rice cakes and dry plant fibre strands were examined for viable cell counts during 6 months storage at 4 and 25 °C. None of the yeast cultures showed a significant loss in viable cell count during 6 months of storage at 4 °C upon lyophilisation and preservation in dry rice cakes. During storage at 25 °C in the dark, yeast cultures preserved in dry rice cakes, and lyophilised cultures of Saccharomyces cerevisiae and Issatchenkia orientalis showed no significant loss of viable cells up to 4 months of storage. Yeast cultures preserved in dry plant fibre strands had the greatest loss of viable count during the 6 months of storage at 25 °C. Preservation of yeasts cultures in dry rice cakes provided better survival during storage at 4 °C than lyophilisation. The current study demonstrated that traditional methods can be useful and effective for starter culture preservation in small-scale, low-tech applications. PMID:22806747

Nyanga, Loveness K; Nout, Martinus J R; Smid, Eddy J; Boekhout, Teun; Zwietering, Marcel H



Study of amyloids using yeast  

PubMed Central

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

Wickner, Reed B.; Kryndushkin, Dmitry; Shewmaker, Frank; McGlinchey, Ryan; Edskes, Herman K.



Speciation of chromium in chromium yeast.  


High-performance liquid chromatography was used to separate Cr(III) and Cr(VI) in samples with detection by inductively coupled plasma mass spectrometry(ICP-MS). The separation was achieved on a weak anion exchange column. The mobile phase was pH 7.0 ammonium nitrate solution. The redox reaction between Cr(III) and Cr(VI) was avoided during separation and determination. This separation method could be used to separate the samples with large concentration differences between Cr(III) and Cr(VI). The alkaline digestion was used to extract chromium in solid sample, which had no effect on the retention time and the peak area of the Cr(VI). However, the conversion of Cr(VI) from Cr(III) was observed during alkaline digestion, which displayed positive relation with the ratio of Cr(III) and Cr(VI) in samples. Both Cr(III) and Cr(VI) contents of chromium yeasts cultured in media with different chromium additions were determined. The spike recoveries of Cr(VI) for chromium yeasts were in the range of 95-108 %. PMID:25269546

Guo, Xuena; Liu, Wei; Bai, Xuejing; He, Xiuping; Zhang, Borun



Effect of Sucrose Feeding on the Intestinal Transport of Sugars in Two Strains of Rats  

Microsoft Academic Search

The rates of intestinal transport of dietary monosaccharides and disaccharides were determined in Wistar rats and the carbohydrate-sensitive BHE rats fed either a stock diet or a 65% sucrose diet. Sucrose-fed rats of both strains generally showed large and significant increases in the rates of glucose, a-methylglucose, fructose, and sucrose transport. The transport of galactose, maltose, and lactose did not




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

Microsoft Academic Search

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

B. Li; D. J. Wolyn



Sucrose-phosphate synthase steady-state mRNA increases in ripening kiwifruit  

Microsoft Academic Search

Early during fruit ripening in kiwifruit (Actinidia deliciosa var. deliciosa [A. Chev.], C.F. Liang and A.R. Ferguson cv. Hayward), starch is broken down to sucrose and hexose sugars. Concomitantly, sucrose-phosphate synthase (SPS, EC activity measured with saturating substrate increased, suggesting that SPS is induced in response to a higher requirement for sucrose synthesis [29]. A 2584 bp long partial

Georg Langenkämper; Ronnie McHale; Richard C. Gardner; Elspeth MacRae



The sucrose synthase gene family in Populus : structure, expression, and evolution  

Microsoft Academic Search

Sucrose synthase is a key enzyme in sucrose metabolism in plant cells, and it is involved in the synthesis of cell wall cellulose.\\u000a Although the sucrose synthase gene (SUS) family in the model plants Arabidopsis thaliana has been characterized, little is known about this gene family in trees. This study reports the identification of two novel\\u000a SUS genes in the

Deqiang Zhang; Baohua Xu; Xiaohui Yang; Zhiyi Zhang; Bailian Li



Preparation of polymeric microspheres by the solvent evaporation method using sucrose stearate as a droplet stabilizer.  


Polymeric microspheres containing nicardipine hydrochloride (HCl) as a reference drug were prepared with the acrylic polymers Eudragit RS and L by the solvent evaporation method. Different concentrations of sucrose stearate as a droplet stabilizer were used. Sucrose stearate affected the diffusion rate of the solvent from the preliminary emulsion droplets to the outer phase for the formation of microspheres. Increasing concentrations of sucrose stearate in the formulations caused increasing porosity on the surface of the microspheres. However, a correlation between the concentrations of sucrose stearate and diameters of microspheres could not be assessed. From this point of view, during processing, applied stirring rate was important. PMID:9394253

Yüksel, N; Baykara, T



Expression and regulation of a Bacteroides fragilis sucrose utilization system cloned in Escherichia coli.  

PubMed Central

A Bacteroides fragilis strain isolated from human feces was the source of chromosomal DNA in the construction of plasmid pBS100. The cloned 6-kilobase insert of plasmid pBS100 conferred a sucrose positivity phenotype on transformed cells of Escherichia coli JA221. E. coli JA221(pBS100) cells were able to utilize sucrose as the sole source of carbon because of the presence of sucrase enzyme and sucrose uptake activities. Sucrase activity was inducible in B. fragilis but constitutive in E. coli JA221(pBS100) cells. In sucrose-minimal medium, both B. fragilis and E. coli JA221(pBS100) produced intracellular and extracellular sucrase activities throughout the growth cycle. Osmotic shock experiments performed on E. coli JA221(pBS100) indicated that up to 55% of the sucrase activity was localized in the periplasmic space, 30% was in the cytoplasm, and the remaining 15% was in the cell-free extracellular supernatant fluid. B. fragilis and E. coli JA221(pBS100) actively transported sucrose. Sucrose uptake was induced by sucrose in B. fragilis, whereas the uptake activity in E. coli JA221(pBS100) was constitutive. E. coli JA221(pBS100) appeared to transport sucrose by a phosphotransferase-independent system. B. fragilis transported sucrose only under strictly anaerobic conditions. No uptake activity was detected under aerobic conditions with or without addition of catalase. Images PMID:2166474

Scholle, R R; Steffen, H E; Goodman, H J; Woods, D R



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

PubMed Central

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

Yadav, Rajeev; Sen, Pratik



An inter-laboratory evaluation of selective media for the detection and enumeration of yeasts from blue-veined cheese.  


Five countries representative of laboratories 1-5 evaluated 11 different selective media, designed to suppress mould and bacterial growth and support yeasts growth, for the recovery of yeast populations from blue veined cheeses. In addition, qualitative results were also incorporated. The yeast enumeration values were subjected to statistical analysis using analysis of variance (ANOVA) and the Tukey-Kramer multiple comparison test. With the exception of Laboratory 3, none of the other laboratories was successful in recovering yeasts on all the media. Six of the media proved inadequate for the enumeration of yeasts in the mould invested environment and were therefore omitted from statistical analysis. No significant differences in quantitative data obtained on Rose-Bengal Chloramphenicol Agar (RBCA), Dichloran Rose-Bengal Chloramphenicol Agar (DRBC), Dichloran 18% Glycerol Agar (DG18), and Malt extract agar supplemented with NaCl and oxytetracycline (MES) were detected by four of the collaborating laboratories whereas one laboratory found RBCA to be superior for yeast enumeration. DG18 and Malt Extract Agar with Biphenyl (MEB), however, were ranked superior based on qualitative results compared to the other media, attributed to distinctive individual yeast colonies and mould inhibition. RBCA, DRBC, DG18, and MES on the other hand, all proved to be adequate in supporting yeast colony development for quantitative analysis in samples obtained from blue veined cheeses. PMID:15172480

Viljoen, B C; Knox, A; Beuchat, L R; Deak, T; Malfeito-Ferreira, M; Hansen, T K; Hugo, A; Jakobsen, M; Loureiro, V; Lourens-Hattingh, A; Vasdinnyei, R



Specificity in lipases: A computational study of transesterification of sucrose  

PubMed Central

Computational conformational searches of putative transition states of the reaction of sucrose with vinyl laurate catalyzed by lipases from Candida antarctica B and Thermomyces lanuginosus have been carried out. The dielectric of the media have been varied to understand the role of protein plasticity in modulating the observed regioselective transesterification. The binding pocket of lipase from Candida adapts to the conformational variability of the various substates of the substrates by small, local adjustments within the binding pocket. In contrast, the more constrained pocket of the lipase from Thermomyces adapts by adjusting through concerted global motions between subdomains. This leads to the identification of one large pocket in Candida that accommodates both the sucrose and the lauroyl moieties of the transition state, whereas in Thermomyces the binding pocket is smaller, leading to the localization of the two moieties in two distinct pockets; this partly rationalizes the broader specificity of the former relative to the latter. Mutations have been suggested to exploit the differences towards changing the observed selectivities. PMID:15557256

Fuentes, Gloria; Ballesteros, Anthonio; Verma, Chandra S.



Enhanced translational diffusion of rubrene in sucrose benzoate  

NASA Astrophysics Data System (ADS)

The translational diffusion of rubrene in the fragile molecular glass former, sucrose benzoate (SB) (fragility index m~94), has been studied from Tg+6 K to Tg+71 K(Tg=337 K) by using the technique of holographic fluorescence recovery after photobleaching. In the temperature range of the measurements, the translational relaxation functions were observed to decay exponentially, indicating that Fick's law of diffusion governs the translational motion of rubrene in sucrose benzoate. The value of the translational diffusion coefficient DT obtained from the 1/e time of the translational relaxation function varied from 5.3×10-15 cm2 s-1 at 343 K to 5.0×10-9 cm2 s-1 at 408 K. The temperature dependence of DT for diffusion of rubrene in SB is compared with that of the viscosity and the dielectric relaxation time ?D of SB. The temperature dependence of DT is weaker than that of T/? for T<1.2Tg but tracks the reciprocal of the dielectric relaxation time 1/?D for 1.05Tg

Rajesh Rajian, Justin; Huang, Wei; Richert, Ranko; Quitevis, Edward L.



Nuclear transport of yeast proteasomes.  


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

Enenkel, Cordula



T1R3 taste receptor is critical for sucrose but not Polycose taste  

PubMed Central

In addition to their well-known preference for sugars, mice and rats avidly consume starch-derived glucose polymers (e.g., Polycose). T1R3 is a component of the mammalian sweet taste receptor that mediates the preference for sugars and artificial sweeteners in mammals. We examined the role of the T1R3 receptor in the ingestive response of mice to Polycose and sucrose. In 60-s two-bottle tests, knockout (KO) mice preferred Polycose solutions (4–32%) to water, although their overall preference was lower than WT mice (82% vs. 94%). KO mice also preferred Polycose (0.5–32%) in 24-h two-bottle tests, although less so than WT mice at dilute concentrations (0.5–4%). In contrast, KO mice failed to prefer sucrose to water in 60-s tests. In 24-h tests, KO mice were indifferent to 0.5–8% sucrose, but preferred 16–32% sucrose; this latter result may reflect the post-oral effects of sucrose. Overall sucrose preference and intake were substantially less in KO mice than WT mice. However, when retested with 0.5–32% sucrose solutions, the KO mice preferred all sucrose concentrations, although they drank less sugar than WT mice. The experience-induced sucrose preference is attributed to a post-oral conditioned preference for the T1R3-independent orosensory features of the sugar solutions (odor, texture, T1R2-mediated taste). Chorda tympani nerve recordings revealed virtually no response to sucrose in KO mice, but a near-normal response to Polycose. These results indicate that the T1R3 receptor plays a critical role in the taste-mediated response to sucrose but not Polycose. PMID:19091911

Zukerman, Steven; Glendinning, John I.; Margolskee, Robert F.; Sclafani, Anthony



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


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, sucrose phosphate synthase (SPS, EC, and ADP-glucose pyrophosphorylase (ADPGPPase, EC 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

Suzuki, Yasuo; Dandekar, Abhaya M



280 EXPRESSION IN YEAST [23] [23] Manipulating Yeast Genome Using Plasmid Vectors  

E-print Network

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

Botstein, David



E-print Network

APPENDIX 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. Yeast cells grow well on a minimal medium containing dextrose (glucose) as a carbon source and salts

Winston, Fred


Pre-Absorbing Antibody with Yeast Cells Preparation of Fixed Yeast  

E-print Network

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

Aris, John P.


A New Approach to the Isolation of Genomic DNA from Yeast and Fungi: Preparation of DNA-containing Cell Envelopes and Their Use in PCR  

Microsoft Academic Search

A simple and rapid procedure for the preparation of yeast and fungal DNA samples useful in PCR amplification was developed. The DNA was purified from proteins, lipids, polysaccharides, and other impurities by high-temperature extraction (in a boiling water bath) with buffer solutions containing chaotropic salts. Under these conditions, yeast and fungal cell envelopes remain unbroken and retain the original DNA

V. N. Danilevich; E. V. Grishin



The yeasts of cheese brines.  


A total of 365 yeasts were isolated from the brines of soft, semihard and hard cheeses from different manufacturers. Identification was based on 131 characteristics, primarily employing a method with microtitration plates. Most brines exhibited a characteristic yeast flora. The predominant strains proved to be mainly Debaryomyces hansenii and Candida versatilis. In a few brines Trichosporon beigelii, C. rugosa, C. intermedia, Kluyveromyces marxianus, Saccharomyces sp. and C. tenuis/polymorpha were predominant. Also of importance were C. tropicalis, C. parapsilosis, C. zeylanoides, Issatchenkia orientalis and Geotrichum klebahnii. Not all strains could be clearly identified. Lists of characters are provided for subdividing D. hansenii and T. beigelii. The specificity of the yeast flora of brines is assumed to contribute to the sensory variety of cheeses. PMID:2282287

Seiler, H; Busse, M



Cdc42 Oscillations in Yeasts  

NSDL National Science Digital Library

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.

Felipe O. Bendezu (Switzerland;University of Lausanne REV); Sophie G. Martin (Switzerland;University of Lausanne REV)



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

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

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



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

Microsoft Academic Search

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)

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



Effect of sucrose concentration on sucrose-dependent adhesion and glucosyltransferase expression of S. mutans in children with severe early-childhood caries (S-ECC).  


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

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



Yeast effects on Pinot noir wine phenolics, color, and tannin composition.  


Extraction and stabilization of wine phenolics can be challenging for wine makers. This study examined how yeast choice affected phenolic outcomes in Pinot noir wine. Five yeast treatments were applied in replicated microvinification, and wines were analyzed by UV-visible spectrophotometry. At bottling, yeast treatment Saccharomyces cerevisiae RC212 wine had significantly higher concentrations of total pigment, free anthocyanin, nonbleachable pigment, and total tannin and showed high color density. Some phenolic effects were retained at 6 months' bottle age, and RC212 and S. cerevisae EC1118 wines showed increased mean nonbleachable pigment concentrations. Wine tannin composition analysis showed three treatments were associated with a higher percentage of trihydroxylated subunits (skin tannin indicator). A high degree of tannin polymerization was observed in wines made with RC212 and Torulaspora delbruekii , whereas tannin size by gel permeation chromatography was higher only in the RC212 wines. The results emphasize the importance of yeast strain choice for optimizing Pinot noir wine phenolics. PMID:24011384

Carew, Anna L; Smith, Paul; Close, Dugald C; Curtin, Chris; Dambergs, Robert G



Enzymatic process for the fractionation of baker's yeast cell wall (Saccharomyces cerevisiae).  


?-Glucans, homopolymers of glucose, are widespread in many microorganisms, mushrooms and plants. They have attracted attention because of their bioactive and medicinal functions. One important source of ?-glucans is the cell wall of yeasts, especially that of baker's yeast Saccharomyces cerevisiae. Several processes for the isolation of ?-glucans, using alkali, acid or a combination of both, result in degradation of the polymeric chains. In this paper, we have an enzymatic process for the isolation of glucans from yeast cell walls. As a result, ?-glucans were obtained in a yield of 18.0% of the original ratio in the yeast cell walls. Therefore, this isolation process gave a better yield and higher ?-glucan content than did traditional isolation methods. Furthermore, results showed that each extraction step of ?-glucan had a significant effects on its chemical properties. PMID:24912704

Borchani, Chema; Fonteyn, Fabienne; Jamin, Guilhem; Paquot, Michel; Blecker, Christophe; Thonart, Philippe



Production and chemical characterization of an exopolysaccharide synthesized by psychrophilic yeast strain Sporobolomyces salmonicolor AL? isolated from Livingston Island, Antarctica.  


The exopolysaccharide (EPS) production by psychrophilic Antarctic yeast Sporobolomyces salmonicolor AL? reached the maximum yield in medium containing sucrose (50 g/L) and diammonium sulfate (2.5 g/L) after a 5-d fermentation (5.64 g/L) at 22 °C, the dynamic viscosity of the culture broth reaching (after 5 d) 15.4 mPa s. EPS showed a mannan-like structure and high molar mass, and did not affect cellular viability and proliferation of murine macrophages. It exhibited also a protective effect against the toxic activity of Avarol. PMID:21253901

Poli, A; Anzelmo, G; Tommonaro, G; Pavlova, K; Casaburi, A; Nicolaus, B



The Yeast Nuclear Pore Complex  

PubMed Central

An understanding of how the nuclear pore complex (NPC) mediates nucleocytoplasmic exchange requires a comprehensive inventory of the molecular components of the NPC and a knowledge of how each component contributes to the overall structure of this large molecular translocation machine. Therefore, we have taken a comprehensive approach to classify all components of the yeast NPC (nucleoporins). This involved identifying all the proteins present in a highly enriched NPC fraction, determining which of these proteins were nucleoporins, and localizing each nucleoporin within the NPC. Using these data, we present a map of the molecular architecture of the yeast NPC and provide evidence for a Brownian affinity gating mechanism for nucleocytoplasmic transport. PMID:10684247

Rout, Michael P.; Aitchison, John D.; Suprapto, Adisetyantari; Hjertaas, Kelly; Zhao, Yingming; Chait, Brian T.



Chromatin and Transcription in Yeast  

PubMed Central

Understanding the mechanisms by which chromatin structure controls eukaryotic transcription has been an intense area of investigation for the past 25 years. Many of the key discoveries that created the foundation for this field came from studies of Saccharomyces cerevisiae, including the discovery of the role of chromatin in transcriptional silencing, as well as the discovery of chromatin-remodeling factors and histone modification activities. Since that time, studies in yeast have continued to contribute in leading ways. This review article summarizes the large body of yeast studies in this field. PMID:22345607

Rando, Oliver J.; Winston, Fred



Feature extraction Feature extraction  

E-print Network

(hyperspectral sensors) Meteosat thermal IR channel hyperspectral "image cube" #12;Raw intensities · ProsFeature extraction #12;Feature extraction · Image interpretation: extract information from images · but the desired information may not be explicit in the raw observed pixel intensities · Transform image to make

Giger, Christine


Feature extraction Feature extraction  

E-print Network

(hyperspectral sensors) Meteosat thermal IR channel hyperspectral "image cube" #12;Raw intensities ! � ProsFeature extraction #12;Feature extraction ! � Image interpretation: extract information from images � but the desired information may not be explicit in the raw observed pixel intensities � Transform image to make

Giger, Christine


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

Microsoft Academic Search

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

Chafik Hdider; Yves Desjardins



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

NASA Astrophysics Data System (ADS)

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%.

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



Sucrose-Diet Feeding Induces Gene Expression of Heat Shock Protein in Rat Brain under Stress  

Microsoft Academic Search

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

Haruaki Kageyama; Eiji Suzuki; Takayuki Kashiwa; Masao Kanazawa; Toshimasa Osaka; Shuichi Kimura; Yoshio Namba; Shuji Inoue



Repeated Cocaine Experience Facilitates Sucrose-Reinforced Operant Responding in Enriched and Isolated Rats  

ERIC Educational Resources Information Center

The purpose of the present experiment was to determine whether repeated cocaine exposure differentially affects sucrose-reinforced operant responding in rats raised in an enriched condition (EC) or an isolated condition (IC). Specifically, the performance of EC and IC rats pressing a lever for sucrose under a high fixed-ratio schedule (FR 30)…

Klein, Emily D.; Gehrke, Brenda J.; Green, Thomas A.; Zentall, Thomas R.; Bardo, Michael T.



Evaluation of Traditional Production Process of Rock Candy and Optimization of Sucrose Crystallization (Part 1)  

Microsoft Academic Search

The rock candy is the grown sucrose crystal which its thickness fluctuating from 3 to 30 mm. In this process, the large sucrose crystals have been produced by cooling the supersaturated solution. The mentioned method has not changed up to now and in these years many efforts were done to optimize the production process. The production of rock Candy through

A. Gholamhosseinpour; M. J. Varidi; M. Elahi; F. Shahidi


How homogeneous are the trehalose, maltose and sucrose water solutions ? An Insight from Molecular Dynamics simulations  

Microsoft Academic Search

The structural properties resulting from the reciprocal influence between water and three well-known homologous disaccharides, namely trehalose, maltose and sucrose, in aqueous solutions have been investigated in the 4-66 wt % concentration range by means of molecular dynamics computer simulations. Hydration numbers clearly show that trehalose binds to a larger number of water molecules than do maltose or sucrose, thus

A. Lerbret; P. Bordat; F. Affouard; M. Descamps; F. Migliardo



Potential of mean force between two ions in a sucrose rich aqueous solution  

Microsoft Academic Search

Molecular dynamics and potential of mean force (PMF) calculations are performed on an aqueous sucrose solution of an ion pair to investigate how ionic interactions are modified by the presence of the sugar. The presence of sucrose is shown to deepen the PMF minimum for Na–Cl ion pair, with an overall behavior compatible with continuum electrostatics. The comparison of PMF

Vincenzo Martorana; L. La Fata; D. Bulone; P. L. San Biagio



Growth velocities of ice in supercooled water and aqueous sucrose solutions  

Microsoft Academic Search

Measurements have been made of the component velocities parallel to and normal to the basal plane of ice growing in supercooled water and aqueous sucrose solutions at supercoolings up to 10°C. It has been found that there are discontinuities in the velocity curves for the sucrose solutions. It is inferred that these are due to a growth mechanism change.

W. C. Macklin; B. F. Ryan



Effects of Salts on the Initial Thermal Degradation of Concentrated Aqueous Solutions of Sucrose  

Microsoft Academic Search

The effects of salts and other solutes on the degradation of highly pure sucrose in concentrated aqueous solutions (?65°Brix or % dissolved solids) at 100°C were investigated. Polarimetry and ion chromatography with pulsed amperometric detection (ICIPAD) were used to quantify sucrose degradation. Pseudo-first order kinetic constants of initial degradation rates were calculated. Salt and solute effects were first considered with

G. Eggleston; J. R. Vercellotti; L. A. Edy; M. A. Clarke



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

NASA Technical Reports Server (NTRS)

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.

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



Impact of Weighting Agents and Sucrose on Gravitational Separation of Beverage Emulsions  

Microsoft Academic Search

The influence of weighting agents and sucrose on gravitational separation in 1 wt % oil-in-water emulsions was studied by measuring changes in the intensity of backscattered light from the emulsions with height. Emulsions with different droplet densities were prepared by mixing weighting agents (brominated vegetable oil (BVO), ester gum (EG), damar gum (DG), or sucrose acetate isobutyrate (SAIB)) with soybean

Ratjika Chanamai; D. Julian McClements



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


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

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



New sucrose cocoate based vesicles: Preparation characterization and skin permeation studies  

Microsoft Academic Search

A commercial sucrose cocoate surfactant was used to obtain a new vesicular system for transdermal drug delivery. The preparation, the dimensional and morphological characterizations and the skin permeation profile of these new niosomes were evaluated. Moreover we studied the possible employment of mixture of sucrose cocoate and cholesterol at different weigh ratios for the vesicles preparation and we analyzed the

Lorena Tavano; Rita Muzzalupo; Roberta Cassano; Sonia Trombino; Teresa Ferrarelli; Nevio Picci



Mineral balances in humans as affected by fructose, high fructose corn syrup and sucrose  

Microsoft Academic Search

The utilization of selected minerals when sugars were supplemented to basal diets was investigated in two separate, laboratory-controlled human feeding studies. Fructose-fed subjects had higher fecal excretions of iron and magnesium than did subjects fed sucrose. Apparent iron, magnesium, calcium, and zinc balances tended to be less positive during the fructose feeding period as compared to balances during the sucrose

Rao Ivaturi; Constance Kies



Yeast community survey in the Tagus estuary  

Microsoft Academic Search

The yeast community in the waters of the Tagus estuary, Portugal, was followed for over a year in order to assess its dynamics. Yeast occurrence and incidence were measured and this information was related to relevant environmental data. Yeast occurrence did not seem to depend upon tides, but river discharge had a dramatic impact both on the density and diversity

João M. G. C. F. de Almeida



Red yeast rice: a new hypolipidemic drug  

Microsoft Academic Search

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

Mélanie Journoud; Peter J. H Jones



Yeast communities associated with stingless bees  

Microsoft Academic Search

The yeast communities associated with the stingless bees Tetragonisca angustula, Melipona quadrifasciata and Frieseomelitta varia were studied. The bees T. angustula and F. varia showed a strong association with the yeast Starmerella meliponinorum. M. quadrifasciata more frequently carried a species related to Candida apicola, but also vectored low numbers of S. meliponinorum. Some of the yeasts isolated from adult bees

Carlos A Rosa; Marc-André Lachance; Jana??na O. C Silva; Ana Carolina P Teixeira; Marjorie M Marini; Yasmine Antonini; Rogerio P Martins



Modelling the Yeast Interactome Vuk Janjic1  

E-print Network

Modelling the Yeast Interactome Vuk Janjic´1 , Roded Sharan2 & Natasa Przulj1 1 Department of any empirical observation regarding those networks. Here, we perform a comprehensive analysis of yeast complexity (human and yeast); (3) clear topological difference is present between PPI networks

Shamir, Ron


The effects of isolation-rearing on sucrose consumption in rats.  


Three experiments examined the hypothesis that social isolation of weanling rats potentiates hedonic processes by examining the consumption of sucrose solutions. In the first experiment no differences in consumption were found between socially reared rats and isolation-reared rats allowed to consume sucrose in a familiar test apparatus. In a second experiment socially-reared rats and isolation-reared rats were food and water deprived. Again, no differences in consumption were found. In a third experiment socially reared and isolation-reared rats were allowed to consume sucrose presented in either an ascending or descending order of concentration. When given sucrose in an ascending order of presentation isolation-reared rats consumed significantly more sucrose than socially reared rats. This suggests that isolation-rearing increased the effects of positive contrast, and is consistent with other observations of increased incentive motivation in isolates. PMID:9251970

Hall, F S; Humby, T; Wilkinson, L S; Robbins, T W




PubMed Central

A study of the permeability of calf thymus nuclei isolated in sucrose was carried out with sucrose-14C, glycerol-14C, and carboxydextran-14C (molecular weight, 60,000–90,000). The results indicate that the nuclei are very permeable to both sucrose and glycerol but they exclude the carboxydextran. Results obtained with other low molecular weight non-electrolytes (malonamide-14C, erythritol-14C, D-arabinose-14C, and D-mannitol-14C) are in agreement with the view that the nuclei are freely permeable to these molecular species. A sucrose-impermeable space is also present in these preparations and it has been attributed to the presence of intact cells. The high permeability of nuclei to sucrose was confirmed with Ficoll-separated preparations. The possibility of the presence of a substantial particulate space that allows the penetration of dextran cannot be excluded by these experiments, and this space may correspond to damaged nuclei. PMID:11905205

Kodama, Robert M.; Tedeschi, Henry



Studies on the permeability of calf thymus nuclei isolated in sucrose.  


A study of the permeability of calf thymus nuclei isolated in sucrose was carried out with sucrose-14C, glycerol-14C, and carboxydextran-14C (molecular weight, 60,000-90,000). The results indicate that the nuclei are very permeable to both sucrose and glycerol but they exclude the carboxydextran. Results obtained with other low molecular weight non-electrolytes (malonamide-14C, erythritol-14C, D-arabinose-14C, and D-mannitol-14C) are in agreement with the view that the nuclei are freely permeable to these molecular species. A sucrose-impermeable space is also present in these preparations and it has been attributed to the presence of intact cells. The high permeability of nuclei to sucrose was confirmed with Ficoll-separated preparations. The possibility of the presence of a substantial particulate space that allows the penetration of dextran cannot be excluded by these experiments, and this space may correspond to damaged nuclei. PMID:11905205

Kodama, R M; Tedeschi, H



Identification of sucrose synthase as an actin-binding protein  

NASA Technical Reports Server (NTRS)

Several lines of evidence indicate that sucrose synthase (SuSy) binds both G- and F-actin: (i) presence of SuSy in the Triton X-100-insoluble fraction of microsomal membranes (i.e. crude cytoskeleton fraction); (ii) co-immunoprecipitation of actin with anti-SuSy monoclonal antibodies; (iii) association of SuSy with in situ phalloidin-stabilized F-actin filaments; and (iv) direct binding to F-actin, polymerized in vitro. Aldolase, well known to interact with F-actin, interfered with binding of SuSy, suggesting that a common or overlapping binding site may be involved. We postulate that some of the soluble SuSy in the cytosol may be associated with the actin cytoskeleton in vivo.

Winter, H.; Huber, J. L.; Huber, S. C.; Davies, E. (Principal Investigator)



Storage of Brewing Yeasts by Liquid Nitrogen Refrigeration  

PubMed Central

Many yeast strains are difficult to maintain in culture in a stable state, and long-term preservation by lyophilization, which has proved useful for other fungi, has given poor results with brewing yeasts. As an alternative to continuous subculture, which maximizes strain variability, various methods of cryogenic storage were investigated. Yeast strains were frozen with or without cryoprotectants (such as glycerol or inositol) and stored at -196 C. Recovery after warming was estimated from plate counts, and survivors were screened to detect changes in the frequency of morphological types, respiratory-deficient mutants, and glycerol-sensitive mutants. Strains varied in their sensitivity to freezing, and survival was modified by the growth medium, the freezing munstrua, and the freezing conditions. Suspension of cells in 10% (vol/vol) glycerol, cooled at 1 C/min, warmed rapidly and plated on malt-yeast extract-glucose-peptone agar produced the highest percentage of viable colonies with a minimal change in metabolic characteristics. In two of the strains tested, no significant increase in mutation rate was detected under any of the treatments; the strains were maintained in a stable state and were metabolically comparable to unfrozen strains. In one strain of Saccharomyces uvarum after some freezing treatments, the percentage of respiratory-deficient mutants increased markedly, the fermentation rate declined, and a loss of flocculation occurred. The freezing parameters which increased the level of respiratory-deficient cells should be avoided in maintaining this strain. Maintenance of cultures of brewing yeasts by cryogenic storage has several advantages over other preservation techniques: the method is simple and reproducible, the cultures have remained stable over a 3-year test period, and the viability is high. PMID:16349973

Wellman, A. M.; Stewart, G. G.



Sucrose importation into laticifers of Hevea brasiliensis, in relation to ethylene stimulation of latex production  

PubMed Central

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

Dusotoit-Coucaud, Anais; Brunel, Nicole; Kongsawadworakul, Panida; Viboonjun, Unchera; Lacointe, Andre; Julien, Jean-Louis; Chrestin, Herve; Sakr, Soulaiman



Escherichia coli W shows fast, highly oxidative sucrose metabolism and low acetate formation.  


Sugarcane is the most efficient large-scale crop capable of supplying sufficient carbon substrate, in the form of sucrose, needed during fermentative feedstock production. However, sucrose metabolism in Escherichia coli is not well understood because the two most common strains, E. coli K-12 and B, do not grow on sucrose. Here, using a sucrose utilizing strain, E. coli W, we undertake an in-depth comparison of sucrose and glucose metabolism including growth kinetics, metabolite profiling, microarray-based transcriptome analysis, labelling-based proteomic analysis and (13)C-fluxomics. While E. coli W grew comparably well on sucrose and glucose integration of the omics, datasets showed that during growth on each carbon source, metabolism was distinct. The metabolism was generally derepressed on sucrose, and significant flux rearrangements were observed in central carbon metabolism. These included a reduction in the flux of the oxidative pentose phosphate pathway branch, an increase in the tricarboxylic acid cycle flux and a reduction in the glyoxylate shunt flux due to the dephosphorylation of isocitrate dehydrogenase. But unlike growth on other sugars that induce cAMP-dependent Crp regulation, the phosphoenol-pyruvate-glyoxylate cycle was not active on sucrose. Lower acetate accumulation was also observed in sucrose compared to glucose cultures. This was linked to induction of the acetate catabolic genes actP and acs and independent of the glyoxylic shunt. Overall, the cells stayed highly oxidative. In summary, sucrose metabolism was fast, efficient and led to low acetate accumulation making it an ideal carbon source for industrial fermentation with E. coli W. PMID:25125039

Arifin, Yalun; Archer, Colin; Lim, SooA; Quek, Lake-Ee; Sugiarto, Haryadi; Marcellin, Esteban; Vickers, Claudia E; Krömer, Jens O; Nielsen, Lars K



Saccharomyces Genome Database: the genomics resource of budding yeast.  


The Saccharomyces Genome Database (SGD, 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

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



Saccharomyces Genome Database: the genomics resource of budding yeast  

PubMed Central

The Saccharomyces Genome Database (SGD, 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

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.



Fermentation of levoglucosan with oleaginous yeasts for lipid production.  


This paper reports the production of lipids from non-hydrolyzed levoglucosan (LG) by oleaginous yeasts Rhodosporidium toruloides and Rhodotorula glutinis. Enzyme activity tests of LG kinases from both yeasts indicated that the phosphorylation pathway of LG to glucose-6-phosphate existed. The highest enzyme activity obtained for R. glutinis was 0.22 U/mg of protein. The highest cell mass and lipid production by R. glutinis were 6.8 and 2.7 g/L, respectively from pure LG, and 3.3 and 0.78 g/L from a pyrolytic LG aqueous phase detoxified by ethyl acetate extraction, rotary evaporation and activated carbon. This corresponded to a lipid yield of 13.5 wt.% for pure LG and only 3.9 wt.% for LG in pyrolysis oil. PMID:23425586

Lian, Jieni; Garcia-Perez, Manuel; Chen, Shulin



Antimicrobial activity of Wedelia trilobata crude extracts.  


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

Taddei, A; Rosas-Romero, A J



High biobased content epoxy-anhydride thermosets from epoxidized sucrose esters of Fatty acids.  


Novel highly functional biobased epoxy compounds, epoxidized sucrose esters of fatty acids (ESEFAs), were cross-linked with a liquid cycloaliphatic anhydride to prepare polyester thermosets. The degree of cure or conversion was studied using differential scanning calorimetry (DSC), and the sol content of the thermosets was determined using solvent extraction. The mechanical properties were studied using tensile testing to determine Young's modulus, tensile stress, and elongation at break. Dynamic mechanical analysis (DMA) was used to determine glass-transition temperature, storage modulus, and cross-link density. The nanomechanical properties of the surfaces were studied using nanoindentation to determine reduced modulus and indentation hardness. The properties of coatings on steel substrates were studied to determine coating hardness, adhesion, solvent resistance, and mechanical durability. Compared with the control, epoxidized soybean oil, the anhydride-cured ESEFAs have high modulus and are hard and ductile, high-performance thermoset materials while maintaining a high biobased content (71-77% in theory). The exceptional performance of the ESEFAs is attributed to the unique structure of these macromolecules: well-defined compact structures with high epoxide functionality. These biobased thermosets have potential uses in applications such as composites, adhesives, and coatings. PMID:21561167

Pan, Xiao; Sengupta, Partha; Webster, Dean C



Producing aglycons of ginsenosides in bakers' yeast  

PubMed Central

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

Dai, Zhubo; Wang, Beibei; Liu, Yi; Shi, Mingyu; Wang, Dong; Zhang, Xianan; Liu, Tao; Huang, Luqi; Zhang, Xueli



Evaluation of Composition and Antimicrobial Activity of Supercritical Fluid Extract of Leaves of Vitex negundo  

PubMed Central

Supercritical fluid extract of leaves of Vitex negundo was tested for its antimicrobial potential and was compared with that of ethanol extract, ether extract and hydrodistilled oil of leaves. The chemical constituents of extracts were studied by chromatographic techniques. Extracts were evaluated for antimicrobial potential against bacterial strains like Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and yeast Candida albicans. Extracts showed prominent antibacterial activity against Bacillus subtilis and Staphylococcus aureus. Supercritical fluid extract exhibited good antibacterial potential. PMID:21695000

Nagarsekar, K. S.; Nagarsenker, M. S.; Kulkarni, S. R.



Histological Intestinal Recovery in Chickens Refed Dietary Sugar Cane Extract  

Microsoft Academic Search

Sugar cane extract (SCE), the residue after removing glucose, fructose, and sucrose from sugar cane juice, has growth-promoting, antistress, and immunosti- mulation effects. The objective of this study was to investi- gate the effects of refeeding dietary SCE on recovery of BW and intestinal histology after withdrawing feed from chickens. Forty-eight male Sanuki Cochin chickens were assigned randomly to 6

K. Yamauchi; K. Koge; T. Ebashi


Observations on the Yeast Lipomyces  

Microsoft Academic Search

IN 1946, Starkey1 isolated and described a soil yeast characterized by a peculiar method of spore formation after a relatively long period of growth on solid medium. Large, round vegetative cells containing fat globules gave rise to irregularly shaped protuberances in which were afterwards formed 4-16 or more lightly pigmented spores. Lodder and Kregervan Rij2 considered these spores to be

Catherine Roberts



Genetically modified industrial yeast ready for application.  


Tremendous progress in the genetic engineering of yeast had been achieved at the end of 20th century, including the complete genome sequence, genome-wide gene expression profiling, and whole gene disruption strains. Nevertheless, genetically modified (GM) baking, brewing, wine, and sake yeasts have not, as yet, been used commercially, although numerous industrial recombinant yeasts have been constructed. The recent progress of genetic engineering for the construction of GM yeast is reviewed and possible requirements for their application are discussed. 'Self-cloning' yeast will be the most likely candidate for the first commercial application of GM microorganisms in food and beverage industries. PMID:16233347

Akada, Rinji



Gibberellins, jasmonate and abscisic acid modulate the sucrose-induced expression of anthocyanin biosynthetic genes in Arabidopsis  

Microsoft Academic Search

Summary • Anthocyanins are secondary metabolites, which play an important role in the physiology of plants. Both sucrose and hormones regulate anthocyanin synthesis. Here, the interplay between sucrose and plant hormones was investigated in the expression of sucrose-regulated genes coding for anthocyanin biosynthetic enzymes in Arabidopsis seedlings.  The expression pattern of 14 genes involved in the anthocyanin biosynthetic pathway,

Elena Loreti; Giovanni Povero; Giacomo Novi; Cinzia Solfanelli; Amedeo Alpi; Pierdomenico Perata




Microsoft Academic Search

Various studies have indicated that table sugar (sucrose) was a potent cariogenic factor in the purified diets that have been used to induce caries in the Norway rat (Sognnaes, '48; Haldi and Wynn, '52). The present study was undertaken to determine whether sucrose in the solid form is more or less cariogenic than sucrose in solution. This was possible through



Contraction and Action Potentials of Frog Heart Muscles Soaked in Sucrose Solution  

PubMed Central

Isolated auricles or ventricles from the frog continue to contract, either spontaneously or when stimulated, for from 2 to 4 hours after they are placed in isotonic sucrose solution. After the muscles stop contracting in sucrose solution, contractility is partially restored when the muscles are placed in chloride Ringer's. However, contractility is usually not restored if the muscles are placed in sulfate Ringer's. Ventricles soaked in sucrose solution at 4–7°C continue to contract for 12 to 24 hours and during the first few hours in sucrose solution the contractions often are enhanced. Several types of experiment indicate that the sucrose solution does replace the Ringer's in the extracellular space. Auricles and ventricles also continue to conduct action potentials, with an overshoot, for from 30 to 360 minutes after being placed in sucrose solution. Muscles soaked in sucrose until they are inexcitable rapidly recover in chloride Ringer's but often fail to recover in sulfate Ringer's. The results are discussed in relation to theories about the generation of the action potential in cardiac muscle, and the role of the extracellular fluid in contraction. PMID:13924542

Van der Kloot, William G.; Rubin, Nira S.



Promotion of Flowering in Brassica campestris L. cv Ceres by Sucrose  

PubMed Central

Flower initiation of the quantitative long-day plant Brassica campestris cv Ceres was earlier and at a lower final leaf number when sucrose was added to the medium in which plants were grown in sterile culture. The optimal concentration of sucrose was 40 to 80 millimolar. This flower-promoting effect of sucrose was not osmotic, as mannitol, sodium chloride, and polyethylene glycol were not effective at equal osmotic potentials. Seedlings grown heterotrophically after treatment with 4-chloro-5-(dimethylamino)-2-phenyl-3-(2H)-pyridazinone to prevent chlorophyll accumulation were also induced to form flower primordia earlier as the sucrose concentration in the medium was increased up to 80 millimolar. Inclusion of 4 millimolar sodium nitrate in the culture medium of green plants did not reduce the flower-promoting effects of sucrose but delayed initiation in plants grown without added sucrose. Removal of CO2 during a single main or supplementary light period, or both, greatly reduced flower initiation. It is concluded that sucrose may be an important controlling factor determining floral initiation in Brassica. PMID:16663739

Friend, Douglas J. C.; Bodson, Monique; Bernier, Georges



Sucrose Synthase Localization during Initiation of Seed Development and Trichome Differentiation in Cotton Ovules.  

PubMed Central

Sucrose synthase in cotton (Gossypium hirsutum L.) ovules was immunolocalized to clarify the relationship between this enzyme and (a) sucrose import/utilization during initiation of seed development, (b) trichome differentiation, and (c) cell-wall biosynthesis in these rapidly elongating "fibers." Analyses focused on the period immediately before and after trichome initiation (at pollination). Internal tissues most heavily immunolabeled were the developing nucellus, adjacent integument (inner surface), and the vascular region. Little sucrose synthase was associated with the outermost epidermis on the day preceding pollination. However, 1 d later, immunolabel appeared specifically in those epidermal cells at the earliest visible phase of trichome differentiation. The day following pollination, these cells had elongated 3- to 5-fold and showed a further enhancement of sucrose synthase immunolabel. Levels of sucrose synthase mRNA also increased during this period, regardless of whether pollination per se had occurred. Timing of onset for the cell-specific localization of sucrose synthase in young seeds and trichome initials indicates a close association between this enzyme and sucrose import at a cellular level, as well as a potentially integral role in cell-wall biosynthesis. PMID:12228669

Nolte, K. D.; Hendrix, D. L.; Radin, J. W.; Koch, K. E.



Effect of repeated doses of sucrose during heel stick procedure in preterm neonates.  


The purpose of this randomized clinical trial was to test the efficacy of repeated versus single dose sucrose to decrease pain from routine heel stick procedures in preterm neonates. Infants (n = 48) in the first week of life with a mean gestational age of 31 weeks received 0.05 ml of 24% sucrose solution or sterile water by mouth (1) 2 min prior to actual lancing of the heel; (2) just prior to lancing, and (3) 2 min after lancing. The single-dose group received sucrose for the first dose and water for the second and third dose; the repeated-dose group received sucrose three times, and the placebo group received only water. The Premature Infant Pain Profile (PIPP) scores were obtained for five 30-second blocks from lancing. Both sucrose groups had lower PIPP scores (single sucrose pain scores, 6.8-8.2, p = 0.07; repeated sucrose pain scores, 5.3-6. 2, p < 0.01) than water (pain scores 7.9-9.1), and in the last block, the repeated dose had lower scores than the single dose (6.2 vs. 8. 2, p < 0.05). PMID:9925903

Johnston, C C; Stremler, R; Horton, L; Friedman, A



Sucrose fermentation by Fusobacterium mortiferum ATCC 25557: transport, catabolism, and products.  

PubMed Central

Studies of sucrose utilization by Fusobacterium mortiferum ATCC 25557 have provided the first definitive evidence for phosphoenolpyruvate-dependent sugar:phosphotransferase activity in the family Bacteroidaceae. The phosphoenolpyruvate-dependent sucrose:phosphotransferase system and the two enzymes required for the dissimilation of sucrose 6-phosphate are induced specifically by growth of F. mortiferum on the disaccharide. Monomeric sucrose 6-phosphate hydrolase (M(r), 52,000) and a dimeric ATP-dependent fructokinase (subunit M(r), 32,000) have been purified to electrophoretic homogeneity. The physicochemical and catalytic properties of these enzymes have been examined, and the N-terminal amino acid sequences for both proteins are reported. The characteristics of sucrose 6-phosphate hydrolase and fructokinase from F. mortiferum are compared with the same enzymes from both gram-positive and gram-negative species. Butyric, acetic, and D-lactic acids are the end products of sucrose fermentation by F. mortiferum. A pathway is proposed for the translocation, phosphorylation, and metabolism of sucrose by this anaerobic pathogen. Images PMID:1533618

Thompson, J; Nguyen, N Y; Robrish, S A



A small-scale method for quantitation of carotenoids in bacteria and yeasts.  


Microbial carotenoids are difficult to extract because of their embedding into a compact matrix and prominent sensitivity to degradation. Especially for carotenoid analysis of bacteria and yeasts, there is lack of information about capability, precision and recovery of the method used. Accordingly, we investigated feasibility, throughput and validity of a new small-scale method using Micrococcus luteus and Rhodotorula glutinis for testing purposes. For disintegration and extraction, we combined primarily mild techniques: enzymatically we used combinations of lysozyme and lipase for bacteria as well as lyticase and lipase for yeasts. Additional mechanical treatment included sonication and freeze-thawing cycles. Chemical treatment with dimethylsulfoxide was applied for yeasts only. For extraction we used a methanol-chloroform mixture stabilized efficiently with butylated hydroxytoluene and alpha-tocopherol. Separation of compounds was achieved with HPLC, applying a binary methanol/tert-butyl methyl ether gradient on a polymer reversed C30 phase. Substances of interest were detected and identified applying a photodiode-array (PDA) and carotenoids quantitated as all-trans-beta-carotene equivalents. For evaluation of recovery and reproducibility of the extraction method, we used beta-8'-apo-carotenal as internal standard. The method provides a sensitive tool for the determination of carotenoids from bacteria and yeasts and also for small changes in carotenoid spectrum of a single species. Corequisite large experiments are facilitated by the high throughput of the method. PMID:17509707

Kaiser, Philipp; Surmann, Peter; Vallentin, Gerald; Fuhrmann, Herbert



Screening of yeasts for cell-free production of ( R )-phenylacetylcarbinol  

Microsoft Academic Search

105 yeast strains from 10 genera and 40 species were evaluated for cell-free production of (R)-phenylacetylcarbinol (PAC), the chiral precursor in the manufacture of the pharmaceuticals ephedrine and pseudoephedrine. Carboligase activity of pyruvate decarboxylase (PDC), forming PAC from benzaldehyde and pyruvate, was found in extracts of 98 strains. PAC was not formed from benzaldehyde and acetaldehyde, an activity of bacterial

Bettina Rosche; Michael Breuer; Bernhard Hauer; Peter L. Rogers



Effects of Solid-State Yeast Treatment on the Antioxidant Properties and Protein and Fiber  

E-print Network

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

Liu, Jian-Guo


Validation of a Flour-Free Model Dough System for Throughput Studies of Baker's Yeast  

Microsoft Academic Search

Evaluation of gene expression in baker's yeast requires the extraction and collection of pure samples of RNA. However, in bread dough this task is difficult due to the complex composition of the system. We found that a liquid model system can be used to analyze the transcriptional response of industrial strains in dough with a high sugar content. The production

Joaquin Panadero; Francisca Randez-Gil; Jose Antonio Prieto



Differential effects of sucrose and fructose on dietary obesity in four mouse strains  

PubMed Central

We examined sugar-induced obesity in mouse strains polymorphic for Tas1r3, a gene that codes for the T1R3 sugar taste receptor. The T1R3 receptor in the FVB and B6 strains has a higher affinity for sugars than that in the AKR and 129P3 strains. In Experiment 1, mice had 40 days of access to lab chow plus water, sucrose (10 or 34%), or fructose (10 or 34%) solutions. The strains consumed more of the sucrose than isocaloric fructose solutions. The pattern of strain differences in caloric intake from the 10% sugar solutions was FVB > 129P3 = B6 > AKR; and that from the 34% sugar solutions was FVB > 129P3 > B6 ? AKR. Despite consuming more sugar calories, the FVB mice resisted obesity altogether. The AKR and 129P3 mice became obese exclusively on the 34% sucrose diet, while the B6 mice did so on the 34% sucrose and 34% fructose diets. In Experiment 2, we compared total caloric intake from diets containing chow versus chow plus 34% sucrose. All strains consumed 15-29% more calories from the sucrose-supplemented diet. In Experiment 3, we compared the oral acceptability of the sucrose and fructose solutions, using lick tests. All strains licked more avidly for the 10% sucrose solutions. The results indicate that in mice (a) Tas1r3 genotype does not predict sugar-induced hyperphagia or obesity; (b) sucrose solutions stimulate higher daily intakes than isocaloric fructose solutions; and (c) susceptibility to sugar-induced obesity varies with strain, sugar concentration and sugar type. PMID:20600198

Glendinnning, John I.; Breinager, Lindsey; Kyrillou, Emily; Lacuna, Kristine; Rocha, Rotsen; Sclafani, Anthony



Considerations for Using Sucrose to Reduce Procedural Pain in Preterm Infants  

PubMed Central

Preterm and critically ill newborns admitted to a NICU undergo repeated skin-breaking procedures that are necessary for their survival. Sucrose is rapidly becoming the accepted clinical standard nonpharmacologic intervention for managing acute procedural pain for these infants. Although shown to be safe in single doses, only 4 studies have evaluated the effects of repeated doses of sucrose over relatively short periods of time. None has examined the use of sucrose throughout the NICU stay, and only 1 study evaluated the neurodevelopmental outcomes after repeated doses of sucrose. In that study, infants born at <31 weeks’ gestational age and exposed to >10 doses per day in the first week of life were more likely to show poorer attention and motor development in the early months after discharge from the NICU. Results of studies in animal models have suggested that the mechanism of action of sucrose is through opioid pathways; however, in human infants, little has been done to examine the physiologic mechanisms involved, and the findings reported thus far have been ambiguous. Drawing from the growing animal literature of research that has examined the effects of chronic sugar exposure, we describe alternative amine and hormone pathways that are common to the processing of sucrose, attention, and motor development. In addition, are view of the latest research to examine the effects of repeated sucrose on pain processing is presented. These 2 literatures each can inform the other and can provide an impetus to initiate research to examine not only the mechanisms involved in the calming mechanisms of sucrose but also in the long-term neurodevelopmental effects of repeated sucrose in those infants born extremely preterm or critically ill. PMID:20403938

Holsti, Liisa; Grunau, Ruth E.



Synthesis of a sucrose dimer with enone tether; a study on its functionalization.  


The reaction of appropriately functionalized sucrose phosphonate with sucrose aldehyde afforded a dimer composed of two sucrose units connected via their C6-positions ('the glucose ends'). The carbonyl group in this product (enone) was stereoselectively reduced with zinc borohydride and the double bond (after protection of the allylic alcohol formed after reduction) was oxidized with osmium tetroxide to a diol. Absolute configurations of the allylic alcohol as well as the diol were determined by circular dichroism (CD) spectroscopy using the in situ dimolybdenum methodology. PMID:24991275

Pakulski, Zbigniew; Gajda, Norbert; Jawiczuk, Magdalena; Frelek, Jadwiga; Cmoch, Piotr; Jarosz, S?awomir



Glass transition and water effects on sucrose inversion in noncrystalline carbohydrate food systems  

Microsoft Academic Search

The effects of water and glass transition on the hydrolysis of sucrose by invertase in noncrystalline carbohydrate systems were investigated. Maltodextrin\\/sucrose (2:1) and maltodextrin\\/lactose\\/sucrose (1:1:1) were dissolved in distilled water. Invertase (10 mg\\/17.2 g) was added. Amorphous samples were produced by freeze-drying the solutions. Sorption isotherms were determined gravimetrically at 24 °C over the 0.113–0.763 aw, and over 0.239–0.764 aw, the

Kouame Kouassi; Yrjö H Roos



Modeling of sucrose crystallization kinetics: The influence of glucose and fructose  

NASA Astrophysics Data System (ADS)

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.

Ouiazzane, S.; Messnaoui, B.; Abderafi, S.; Wouters, J.; Bounahmidi, T.



Ethanol production by a new pentose-fermenting yeast strain, Scheffersomyces stipitis UFMG-IMH 43.2, isolated from the Brazilian forest.  


The ability of a recently isolated Scheffersomyces stipitis strain (UFMG-IMH 43.2) to produce ethanol from xylose was evaluated. For the assays, a hemicellulosic hydrolysate produced by dilute acid hydrolysis of sugarcane bagasse was used as the fermentation medium. Initially, the necessity of adding nutrients (MgSO(4)·7H(2)O, yeast extract and/or urea) to this medium was verified, and the yeast extract supplementation favoured ethanol production by the yeast. Then, in a second stage, assays under different initial xylose and cell concentrations, supplemented or not with yeast extract, were performed. All these three variables showed significant (p < 0.05) influence on ethanol production. The best results (ethanol yield and productivity of 0.19 g/g and 0.13 g/l/h, respectively) were obtained using the hydrolysate containing an initial xylose concentration of 30 g/l, supplemented with 5.0 g/l yeast extract and inoculated with an initial cell concentration of 2.0 g/l. S. stipitis UFMG-IMH 43.2 was demonstrated to be a yeast strain with potential for use in xylose conversion to ethanol. The establishment of the best fermentation conditions was also proved to be of great importance to increasing the product formation by this yeast strain. These findings open up new perspectives for the establishment of a feasible technology for ethanol production from hemicellulosic hydrolysates. PMID:21626536

Ferreira, Adriana D; Mussatto, Solange I; Cadete, Raquel M; Rosa, Carlos A; Silva, Silvio S



Isolation and Screening of Yeasts That Ferment d-Xylose Directly to Ethanol  

PubMed Central

Natural habitats of yeasts were examined for the presence of strains able to produce ethanol from d-xylose. Black knots, insect frass, and tree exudates were screened by enrichment in liquid d-xylose-yeast extract medium. These and each d-xylose-assimilating yeast in a collection from cactus fruits and Drosophila spp. were tested for alcohol production from this sugar. Among the 412 isolates examined, 36 produced more than 1 g of ethanol liter?1 from 20 g of d-xylose liter?1, all under aerated conditions. Closer examination of the strains indicated that their time courses of d-xylose fermentation followed different patterns. Some strains produced more biomass than ethanol, and among these, ethanol may or may not be assimilated rapidly after depletion of d-xylose. Others produced more ethanol than biomass, but all catabolized ethanol after carbohydrate exhaustion. Ethanol production appeared best at low pH values and under mild aeration. Possible correlations between the nutritional profiles of the yeasts and their ability to produce ethanol from d-xylose were explored by multivariate analysis. d-Xylose appeared slightly better utilized by yeasts which rate poorly in terms of fermentation. The fermentation of d-glucose had no bearing on d-xylose fermentation. No specific nutritional trait could discriminate well between better d-xylose fermentors and other yeasts. PMID:16346947

Nigam, J. N.; Ireland, R. S.; Margaritis, A.; Lachance, M. A.



Antimicrobial effect of various combinations of plant extracts  

Microsoft Academic Search

The combined extracts of corni fructus, cinnamon and Chinese chive were used to evaluate its antimicrobial activity on common foodborne micro-organisms, including bacteria, yeasts and moulds. The combined extract (8:1:1, v\\/v\\/v) showed an entire antimicrobial spectrum and outstanding inhibitory effect. The combined extract was very stable under heat treatment. The inhibitory effect of the combined extract was greater with more

Pao-Chuan Hsieh; Jeng-Leun Mau; Shu-Hui Huang



Production of flavour-active methionol from methionine metabolism by yeasts in coconut cream.  


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

Seow, Yi-Xin; Ong, Peter K C; Liu, Shao-Quan



Oxidative stress responses in yeast  

Microsoft Academic Search

Yeast, and especially S. cerevisiae, is a unique eukaryotic model organism for studying oxidative stress and its cellular responses. S. cerevisiae has become a very powerful tool to decipher the complexity of these biologically important responses, because it offers the\\u000a relative simplicity of a single celled eukaryotic organism that enables the combination and integration of genetic, biochemical,\\u000a physico-chemical, cell biological,

Michel B. Toledano; Agnes Delaunay; Benoit Biteau; Daniel Spector; Dulce Azevedo


Yeast adaptation on softwood prehydrolysate  

Microsoft Academic Search

Several strains and genera of yeast, includingSaccharomyces cerevisiae D5A,Pachysolen tannophilus, S. cerevisiae K-l,Brettanomyces custersii, Candida shehatae, andCandida acidothermophilum, are screened for growth on dilute acid-pretreated softwood prehydrolysate. Selected softwood species found in forest underbrush\\u000a of the western United States, which contain predominantly hexosan hemicellulose, were studied. This phase of the work emphasized\\u000a debarked Douglas fir. The two best initial isolates

Fcred A. Keller; Delicia Bates; Ray Ruiz; Quang Nguyen



Carbon Partitioning during Sucrose Accumulation in Sugarcane Internodal Tissue.  

PubMed Central

The temporal relationship between sucrose (Suc) accumulation and carbon partitioning was investigated in developing sugarcane internodes. Radiolabeling studies on tissue slices, which contained Suc concentrations ranging from 14 to 42% of the dry mass, indicated that maturation coincided with a redirection of carbon from water-insoluble matter, respiration, amino acids, organic acids, and phosphorylated intermediates into Suc. It is evident that a cycle of Suc synthesis and degradation exists in all of the internodes. The decreased allocation of carbon to respiration coincides with a decreased flux from the hexose pool. Both the glucose and fructose (Fru) concentrations significantly decrease during maturation. The phosphoenolpyruvate, Fru-6-phosphate (Fru-6-P), and Fru-2,6-bisphosphate (Fru-2, 6-P2) concentrations decrease between the young and older internodal tissue, whereas the inorganic phosphate concentration increases. The calculated mass-action ratios indicate that the ATP-dependent phosphofructokinase, pyruvate kinase, and Fru-1,6-bisphosphatase reactions are tightly regulated in all of the internodes, and no evidence was found that major changes in the regulation of any of these enzymes occur. The pyrophosphate-dependent phosphofructokinase reaction is in apparent equilibrium in all the internodes. Substrate availability might be one of the prime factors contributing to the observed decrease in respiration. PMID:12223886

Whittaker, A.; Botha, F. C.



The Effect of Sucrose on the Differentiation of Excised Fern Leaf Tissue into Either Gametophytes of Sporophytes 1  

PubMed Central

Excised juvenile leaves of Microgramma vacciniifolia (Polypodiaceae) develop sporophytic regenerants when grown on mineral agar with sucrose. The ratio of sporophytes to gametophytes produced from the leaf tissue increases with higher percentages of sucrose such that at 4% sucrose, the induction of aposporous gametophytes is a rare occurrence. Experiments varying the osmotic potential with sorbitol and those holding the osmotic potential of the culture medium constant while varying the sucrose level indicate that the effect of sucrose on the differentiation of fern leaf tissue into either gametophyte or sporophyte is nutritional rather than osmotic. A significant effect of sucrose in altering the differentiation of fern leaf tissue is the increased rate of senescence promoted by high sucrose concentrations. Images PMID:16659310

Hirsch, Ann M.



An indirect assay for volatile compound production in yeast strains  

PubMed Central

Traditional flavor analysis relies on gas chromatography coupled to mass spectrometry (GC-MS) methods. Here we describe an indirect method coupling volatile compound formation to an ARO9-promoter-LacZ reporter gene. The resulting ?-galactosidase activity correlated well with headspace solid phase micro extraction (HS/SPME) GC-MS data, particularly with respect to the formation of rose flavor. This tool enables large-scale screening of yeast strains and their progeny to identify the most flavor active strains. PMID:24424137

Ravasio, Davide; Walther, Andrea; Trost, Kajetan; Vrhovsek, Urska; Wendland, Jurgen



Biodegradation of Oil Pollutants by Yeasts and Yeast-Like Fungi.  

National Technical Information Service (NTIS)

In exploring the feasibility of the use of microbial systems for the facilitated biodegradation of waste oils, yeasts and yeast-like fungi from marine, freshwater and terrestrial sources were screened for their ability to utilize hydrocarbons. Mixed cultu...

D. G. Ahearn, N. H. Berner



The Effects of Fruiting Positions on Cellulose Synthesis and Sucrose Metabolism during Cotton (Gossypium hirsutum L.) Fiber Development  

PubMed Central

Cotton (Gossypium hirsutum L.) boll positions on a fruiting branch vary in their contribution to yield and fiber quality. Fiber properties are dependent on deposition of cellulose in the fiber cell wall, but information about the enzymatic differences in sucrose metabolism between these fruiting positions is lacking. Therefore, two cotton cultivars with different sensitivities to low temperature were tested in 2010 and 2011 to quantify the effect of fruit positions (FPs) on fiber quality in relation to sucrose content, enzymatic activities and sucrose metabolism. The indices including sucrose content, sucrose transformation rate, cellulose content, and the activities of the key enzymes, sucrose phosphate synthase (SPS), acid invertase (AI) and sucrose synthase (SuSy) which inhibit cellulose synthesis and eventually affect fiber quality traits in cotton fiber, were determined. Results showed that as compared with those of FP1, cellulose content, sucrose content, and sucrose transformation rate of FP3 were all decreased, and the variations of cellulose content and sucrose transformation rate caused by FPs in Sumian 15 were larger than those in Kemian 1. Under FP effect, activities of SPS and AI in sucrose regulation were decreased, while SuSy activity in sucrose degradation was increased. The changes in activities of SuSy and SPS in response to FP effect displayed different and large change ranges between the two cultivars. These results indicate that restrained cellulose synthesis and sucrose metabolism in distal FPs are mainly attributed to the changes in the activities of these enzymes. The difference in fiber quality, cellulose synthesis and sucrose metabolism in response to FPs in fiber cells for the two cotton cultivars was mainly determined by the activities of both SuSy and SPS. PMID:24586807

Ma, Yina; Wang, Youhua; Liu, Jingran; Lv, Fengjuan; Chen, Ji; Zhou, Zhiguo



Conversion of a putative Agrobacterium sugar-binding protein into a FRET sensor with high selectivity for sucrose.  


Glucose is the main sugar transport form in animals, whereas plants use sucrose to supply non-photosynthetic organs with carbon skeletons and energy. Many aspects of sucrose transport, metabolism, and signaling are not well understood, including the route of sucrose efflux from leaf mesophyll cells and transport across vacuolar membranes. Tools that can detect sucrose with high spatial and temporal resolution in intact organs may help elucidate the players involved. Here, FRET sensors were generated by fusing putative sucrose-binding proteins to green fluorescent protein variants. Plant-associated bacteria such as Rhizobium and Agrobacterium can use sucrose as a nutrient source; sugar-binding proteins were, thus, used as scaffolds for developing sucrose nanosensors. Among a set of putative sucrose-binding protein genes cloned in between eCFP and eYFP and tested for sugar-dependent FRET changes, an Agrobacterium sugar-binding protein bound sucrose with 4 mum affinity. This FLIPsuc-4mu protein also recognized other sugars including maltose, trehalose, and turanose and, with lower efficiency, glucose and palatinose. Homology modeling enabled the prediction of binding pocket mutations to modulate the relative affinity of FLIPsuc-4mu for sucrose, maltose, and glucose. Mutant nanosensors showed up to 50- and 11-fold increases in specificity for sucrose over maltose and glucose, respectively, and the sucrose binding affinity was simultaneously decreased to allow detection in the physiological range. In addition, the signal-to-noise ratio of the sucrose nanosensor was improved by linker engineering. This novel reagent complements FLIPs for glucose, maltose, ribose, glutamate, and phosphate and will be used for analysis of sucrose-derived carbon flux in bacterial, fungal, plant, and animal cells. PMID:16912038

Lager, Ida; Looger, Loren L; Hilpert, Melanie; Lalonde, Sylvie; Frommer, Wolf B



Does an Insect's Unconditioned Response to Sucrose Reveal Expectations of Reward?  

E-print Network

to Sucrose Reveal Expectations of Reward?. PLoS ONE 3(7): e2810. doi:10.1371/journal.pone.0002810 Editor of reward. Further experiments will aim to elucidate the neural substrates underlying reward anticipation

Menzel, Randolf - Institut für Biologie


The interaction of temperature and sucrose concentration on foraging preferences in bumblebees  

NASA Astrophysics Data System (ADS)

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.

Whitney, Heather M.; Dyer, Adrian; Chittka, Lars; Rands, Sean A.; Glover, Beverley J.



Modeling Sucrose Hydrolysis in Dilute Sulfuric Acid Solutions at Pretreatment Conditions for Lignocellulosic Biomass  

SciTech Connect

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 25 g/l sucrose with 0.1-2.0% (w/w) sulfuric acid concentrations were treated at temperatures of 160-200 C for 3-12 min. Sucrose was observed to completely hydrolyze at all treatment conditions. However, appreciable concentrations of fructose and glucose were detected and glucose was found to be significantly more stable than fructose. Different mathematical approaches were used to fit the kinetic parameters for acid-catalyzed thermal degradation of these sugars. Since both sugars may survive dilute acid pretreatment, they could provide an additional carbon source for production of ethanol and other bio-based products.

Bower, S.; Wickramasinghe, R.; Nagle, N. J.; Schell, D. J.



Mutations inducing an active-site aperture in Rhizobium sp. sucrose isomerase confer hydrolytic activity.  


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

Lipski, Alexandra; Watzlawick, Hildegard; Ravaud, Stéphanie; Robert, Xavier; Rhimi, Moez; Haser, Richard; Mattes, Ralf; Aghajari, Nushin



Long term effects of high fat and sucrose diets on obesity and lymphocyte proliferation in mice  

Microsoft Academic Search

Objective  To clarify the effect of prolonged feeding of a high-fat and sucrose, and to clarify the effect of sucrose instead of other\\u000a carbohydrate on obesity and immunity in C57BL\\/6J mice.\\u000a \\u000a \\u000a \\u000a Methods  We investigated the development of obesity and immune cell function in four groups of mice fed high-fat, high-fat plus high-sucrose,\\u000a high-sucrose, and control diet for 7 months.\\u000a \\u000a \\u000a \\u000a Results  Mice fed high-fat

Natsuko Sato-Mito; M. Suzui; H. Yoshino; T. Kaburagi; K. Sato



Sucrose (table sugar) permeability as a diagnostic test for equine gastric ulcers  

E-print Network

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...

O'Conor, Michael



Plasmid-Determined Ability of a 'Salmonella Tennessee' Strain to Ferment Lactose and Sucrose.  

National Technical Information Service (NTIS)

The ability of a Salmonella Tennessee strain to ferment both lactose and sucrose was attributed to a conjugally transmissible plasmid, deoxyribonucleic acid molecular weight 164 megadaltons, bearing the genetic determinants of both fermentation characters...

E. M. Johnson, J. A. Wohlhieter, B. P. Placek, R. B. Sleet, L. S. Baron



21 CFR 184.1983 - Bakers yeast extract.  

... (b) The ingredient meets the...the finished ingredient as a concentrate...pathogen or any harmful microbial toxin. (d) The ingredient is used as a...adjuvant as defined in § 170.3...5 percent in food. (e)...



Assembly of eukaryotic algal chromosomes in yeast  

PubMed Central

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



Yeasts in floral nectar: a quantitative survey  

PubMed Central

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

Herrera, Carlos M.; de Vega, Clara; Canto, Azucena; Pozo, Maria I.



Safety of Iron Sucrose in Hemodialysis Patients Intolerant to Other Parenteral Iron Products  

Microsoft Academic Search

Background\\/Aims: This report summarizes the data gathered in four prospective studies of intravenous iron sucrose therapy administered to iron-deficient hemodialysis patients with a history of intolerance to other parenteral iron preparations. Methods: A total of 130 iron dextran- and\\/or sodium ferric gluconate-sensitive patients received intravenous iron sucrose therapy to correct iron deficiency, and\\/or maintain body iron stores. A history of

Chaim Charytan; Michael H. Schwenk; Mourhege M. Al-Saloum; Bruce S. Spinowitz



Enzymatic synthesis of carbohydrate esters of fatty acid (I) esterification of sucrose, glucose, fructose and sorbitol  

Microsoft Academic Search

The authors attempted to synthesize carbohydrate esters of fatty acids enzymatically in order to overcome the problems associated\\u000a with the chemical processes for the synthesis of commercial sucrose esters. The enzymes used were lipases from microorganisms\\u000a belonging toRhyzopus, Enterbacterium, Aspergillus, Pseudomonas, Chromobacterium, Candida, Mucor andPenicillium. Fatty acids (stearic, oleic and linoleic) and carbohydrates (sucrose, glucose, fructose and sorbitol) used for

Hajime Seino; Tsuyoshi Uchibori; Toshiyuki Nishitani; Sachiko Inamasu



Denitrification in surface soils of a riparian forest: Effects of water, nitrate and sucrose additions  

Microsoft Academic Search

We studied the effects of adding water, nitrate and sucrose on denitrification in a riparian forest that receives nitrate in drainage from cornfields. We used large (3–6m2) flow-through chambers to sample N2O emissions from surface soils. N2 emissions were estimated by comparing N2O efflux in chambers with or without acetylene addition. Water and solutions of nitrate or sucrose were sprinkled

Thomas E. Jordan; Donald E. Weller; David L. Correll



Alteration of starch- sucrose transition in germinating wheat seed under sodium chloride salinity  

Microsoft Academic Search

Alterations in starch-sucrose transition during germination were studied in wheat seeds under saline conditions. NaCI significantly\\u000a reduced the speed of germination and resultant seedling growth, but delayed the degradation of seed storage components. The\\u000a endogenous level of ABA increased while osmotic potential decreased. NaCI also inhibited the expression of ?-amylase. Increasing\\u000a the concentration of NaCI induced the expression of sucrose

Mohammad Abul Kashem; Nilufa Sultana; Takeshi Ikeda; Hidetaka Hori; Tadeusz Loboda; Toshiaki Mitsui



Effect of temperature and sucrose concentration on hydroquinone toxicity in leafy spurge suspension culture cells.  


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

Hogan, M E; Manners, G D



Rheological characterisation of salad-dressing-type emulsions stabilised by egg yolk\\/sucrose distearate blends  

Microsoft Academic Search

The overall objective of this work was to fully characterise the rheological behaviour of oil\\/water emulsions stabilised by egg yolk and a sucrose ester of intermediate hydrophilic-lipophilic balance. The influence of the egg yolk\\/sucrose ester weight ratio in the emulsifier blend was studied by keeping the total amount of emulsifier constant. With this aim, steady state and transient flow tests,

Maria Angustias Riscardo; José E. Moros; José M. Franco; Críspulo Gallegos



Role of orexin/hypocretin in conditioned sucrose-seeking in female rats.  


The orexin/hypocretin system has recently been implicated in reward-seeking, especially for highly salient food and drug rewards. Given that eating disorders affect women more than men, we reasoned that the orexin system may be strongly engaged in female rats, and during periods of food restriction as we recently reported in male rats. Therefore, the present study examined the involvement of the orexin system in operant responding for sucrose, and in cue-induced reinstatement of extinguished sucrose-seeking, in ad libitum fed vs. food-restricted female subjects. Female Sprague Dawley rats were trained to self-administer sucrose pellets, and we determined the effects of pretreatment with the OxR1 receptor antagonist SB 334867 (SB; 10-30 mg/kg) on fixed ratio (FR) sucrose self-administration, and on cue-induced reinstatement of extinguished sucrose-seeking. SB decreased sucrose self-administration in food-restricted but not in ad libitum-fed females. SB did not alter active lever responding during cue-induced reinstatement of sucrose-seeking in either feeding group. These results confirm our previous results in male rats that signaling at the OxR1 receptor is involved in the sucrose reinforcement and self-administration in food-restricted subjects. However, the finding that SB is ineffective at attenuating cue-induced reinstatement in females, but was effective in food-restricted males, leads us to conclude that food seeking induced by conditioned stimuli engages the orexin system differentially in males and females. PMID:25036612

Cason, Angie M; Aston-Jones, Gary



Diffusion of sucrose and aspartame in kappa-carrageenan and gellan gum gels  

Microsoft Academic Search

In the process of sweetness release from the food to the human papillae, diffusion of the sweetener through the food is one of the steps. Information on diffusion behaviour of small molecules like sucrose has been studied mainly in connection with blanching or osmotic processes. In this paper, diffusion constants (D) of both sucrose (100 and 150g\\/l) and aspartame (0.8

S Bayarri; I Rivas; E Costell; L Durán



Design of a simulated moving bed unit for sucrose-betaine separations.  


The results of a series of pulse experiments carried out in a fixed bed column packed with a strongly acid ion-exchange resin and with reference to the separation of an aqueous sucrose-betaine mixture are presented. These data were used to evaluate equilibrium and diffusion parameters for both key components in the frame of linear chromatography theory. The estimated values were used to design a simulated moving bed plant aimed to separate betaine from sucrose in beet molasses. PMID:10749484

Giacobello, S; Storti, G; Tola, G



Osmotic dehydration of sugar beet in combined aqueous solutions of sucrose and sodium chloride  

Microsoft Academic Search

Response surface methodology was used for quantitative investigation of water and solids transfer during osmotic dehydration of sugar beet cossettes in combined aqueous solutions of sucrose and sodium chloride. Effects of immersion time (30–240min), sucrose concentration (30–70%, w\\/w), sodium chloride concentration (0–8%, w\\/w), and temperature of the osmotic solution (30–50°C) were estimated. Quadratic regression equations describing the effects of these

Aleksandar Joki?; Julianna Gyura; Ljubinko Levi?; Zoltan Zavargó



An empirical model to predict the headspace concentration of volatile compounds above solutions containing sucrose  

Microsoft Academic Search

An empirical model was developed to describe and predict the change in gas–liquid partition behaviour of a wide range of volatile compounds in aqueous sucrose solutions. The static equilibrium headspace concentrations of 40 volatiles (from different chemical classes e.g. pyrazines, alcohols, esters and ketones and with different physical properties e.g. volatility and solubility), were measured above aqueous sucrose solutions [0–65%

Ellen N. Friel; Rob. S. T. Linforth; Andrew J. Taylor



Visualization of pressure-shift freezing and thawing of concentrated aqueous sucrose solutions  

Microsoft Academic Search

A visualization of pressure-shift freezing of 0.7 w\\/w sucrose solutions was carried out at three temperatures 268, 253 and 235 K by release of pressure from 200 MPa to atmospheric value. Furthermore, pressure-shift freezing at 268 K and additionally pressure-shift thawing was carried out for a solution of 0.2 sucrose mass fraction. The solid phase observed at 268 K in the case of solution with

L. Kulisiewicz; W. Kowalczyk; A. Baars; A. Delgado



Sucrose content of tubers and discoloration of chips from early summer potatoes  

Microsoft Academic Search

Summary  Potatoes from July 18 and August 1 harvest dates from Gilcrest, Colorado, were placed into 50, 70 and 90 F storage. Non-reducing\\u000a sugar (sucrose), reducing sugar, and chip color index were determined on the harvest date and at three-day intervals through\\u000a a 21-day storage period.\\u000a \\u000a High sucrose content of immature early harvested potatoes may be indirectly involved in after harvest

M. D. Clegg; H. W. Chapman



Hormone and sugar effects on rice sucrose transporter OsSUT1 expression in germinating embryos  

Microsoft Academic Search

The rice (Oryza sativa L.) OsSUT1 gene encodes a sucrose transporter protein. OsSUT1 was suggested to contribute to phloem loading of sucrose. OsSUT1 expression is highly induced in embryos after seeds were imbibed in water and peaked at 2 days after imbibition, but mRNA\\u000a levels decline gradually afterwards. In this study, we demonstrated that phytohormones and sugars regulate OsSUT1 expression. Antagonism

Jia-Yi Chen; Shiang-Lin Liu; Wei Siao; Shu-Jen Wang




Microsoft Academic Search

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

Steven Van Ginkel; ShihWu Sung; Ling Li



Construction of an efficient amylolytic industrial yeast strain containing DNA exclusively derived from yeast  

Microsoft Academic Search

An amylolytic industrial yeast strain of Saccharomyces cerevisiae containing the Schwanniomyces occidentalis SWA2 amylase gene was generated. The new strain contains DNA derived exclusively from yeast and expresses a high starch hydrolyzing activity. Yeast transformation was carried out by an integrative process targeted to a dispensable upstream region of the ILV2 locus, which determines sulfometuron resistance. The SWA2 enzyme was

D Mar??n; A Jiménez; M Fernández Lobato



Extraction and quantitation of astaxanthin from Phaffia rhodozyma  

Microsoft Academic Search

The rapid, quantitative release of astaxanthin and other carotenoids from the yeast Phaffiarhodozyma is described. Hashed cells are ruptured with dimethylsulfoxide (DMSO) and carotenoids extracted into an organic solvent. Extraction and spectrophotometric quantitation of total carotenoids is rapid, reproducible and only small volumes (0.1–2 ml) of culture are required. HPLC analysis in normal phase silica gel column indicates that astaxanthin

J. James Sedmak; Deepthi K. Weerasinghe; Setsuko O. Jolly



Intravenous Iron Sucrose for Children with Iron Deficiency Failing to Respond to Oral Iron Therapy  

PubMed Central

Background For decades parenteral iron has been used in patients with iron deficiency unresponsive to oral iron therapy and in hemodialysis-dependent patients receiving erythropoietin. Newer intravenous (IV) iron formulations such as iron sucrose have replaced high molecular weight iron dextran in dialysis patients; however, the use of parenteral iron in children without renal disease has not been well defined. Procedure Pharmacy records were reviewed on children (? 18 yrs of age) who received IV iron sucrose at Children's Medical Center Dallas between January 1, 2004 and June 30, 2009. Patients who received iron sucrose for chronic renal disease were excluded from analysis. Results Thirty-eight children received iron sucrose for non-renal indications, 13 with iron deficiency refractory to oral iron therapy, 13 with iron malabsorption or dependence on parenteral nutrition, 7 for chronic gastrointestinal blood loss, and 5 for miscellaneous indications. Among these 38 children, who received a total of 510 doses of IV iron sucrose, there were only 6 adverse reactions. Patients in all categories had a good response to the iron sucrose, with a median hemoglobin rise of 1.9 – 3.1 g/dl depending on the indication. Conclusions Parenteral iron is a safe and effective means to treat iron deficiency in children who cannot receive or do not respond to oral iron due to intolerance, poor adherence or iron malabsorption. PMID:21298748

Crary, Shelley E.; Hall, Katherine; Buchanan, George R.



Post-translational regulation of sucrose transporters by direct protein-protein interactions  

PubMed Central

Sucrose transporters are essential membrane proteins for the allocation of carbon resources in higher plants and protein–protein interactions play a crucial role in the post-translational regulation of sucrose transporters affecting affinity, transport capacity, oligomerization, localization, and trafficking. Systematic screening for protein interactors using sucrose transporters as bait proteins helped identifying several proteins binding to sucrose transporters from apple, Arabidopsis, potato, or tomato using the split ubiquitin system. This mini-review summarizes known sucrose transporter-interacting proteins and their potential function in plants. Not all of the identified interaction partners are postulated to be located at the plasma membrane, but some are predicted to be endoplasmic reticulum-residing proteins such as a protein disulfide isomerase and members of the cytochrome b5 family. Many of the SUT1-interacting proteins are secretory proteins or involved in metabolism. Identification of actin and actin-related proteins as SUT1-interacting proteins confirmed the observation that movement of SUT1-containing intracellular vesicles can be blocked by inhibition of actin polymerization using specific inhibitors. Manipulation of expression of these interacting proteins represents one possible way to modify resource allocation by post-translational regulation of sucrose transporters. PMID:23847641

Krugel, Undine; Kuhn, Christina



Sucrose-induced Receptor Kinase SIRK1 Regulates a Plasma Membrane Aquaporin in Arabidopsis*  

PubMed Central

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

Wu, Xu Na; Sanchez Rodriguez, Clara; Pertl-Obermeyer, Heidi; Obermeyer, Gerhard; Schulze, Waltraud X.



Is there a specific role for sucrose in sports and exercise performance?  


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

Wallis, Gareth A; Wittekind, Anna



Doubled sugar content in sugarcane plants modified to produce a sucrose isomer.  


Sucrose is the feedstock for more than half of the world's fuel ethanol production and a major human food. It is harvested primarily from sugarcane and beet. Despite attempts through conventional and molecular breeding, the stored sugar concentration in elite sugarcane cultivars has not been increased for several decades. Recently, genes have been cloned for bacterial isomerase enzymes that convert sucrose into sugars which are not metabolized by plants, but which are digested by humans, with health benefits over sucrose. We hypothesized that an appropriate sucrose isomerase (SI) expression pattern might simultaneously provide a valuable source of beneficial sugars and overcome the sugar yield ceiling in plants. The introduction of an SI gene tailored for vacuolar compartmentation resulted in sugarcane lines with remarkable increases in total stored sugar levels. The high-value sugar isomaltulose was accumulated in storage tissues without any decrease in stored sucrose concentration, resulting in up to doubled total sugar concentrations in harvested juice. The lines with enhanced sugar accumulation also showed increased photosynthesis, sucrose transport and sink strength. This remarkable step above the former ceiling in stored sugar concentration provides a new perspective into plant source-sink relationships, and has substantial potential for enhanced food and biofuel production. PMID:17207261

Wu, Luguang; Birch, Robert G



A nicotinic acetylcholine receptor agonist affects honey bee sucrose responsiveness and decreases waggle dancing.  


A nicotinic acetylcholine receptor agonist, imidacloprid, impairs memory formation in honey bees and has general effects on foraging. However, little is known about how this agonist affects two specific aspects of foraging: sucrose responsiveness (SR) and waggle dancing (which recruits nestmates). Using lab and field experiments, we tested the effect of sublethal doses of imidacloprid on (1) bee SR with the proboscis extension response assay, and (2) free-flying foragers visiting and dancing for a sucrose feeder. Bees that ingested imidacloprid (0.21 or 2.16 ng bee(-1)) had higher sucrose response thresholds 1 h after treatment. Foragers that ingested imidacloprid also produced significantly fewer waggle dance circuits (10.5- and 4.5-fold fewer for 50% and 30% sucrose solutions, respectively) 24 h after treatment as compared with controls. However, there was no significant effect of imidacloprid on the sucrose concentrations that foragers collected at a feeder 24 h after treatment. Thus, imidacloprid temporarily increased the minimum sucrose concentration that foragers would accept (short time scale, 1 h after treatment) and reduced waggle dancing (longer time scale, 24 h after treatment). The effect of time suggests different neurological effects of imidacloprid resulting from the parent compound and its metabolites. Waggle dancing can significantly increase colony food intake, and thus a sublethal dose (0.21 ng bee(-1), 24 p.p.b.) of this commonly used pesticide may impair colony fitness. PMID:22623190

Eiri, Daren M; Nieh, James C



Modulation of receptors and adenylate cyclase activity during sucrose feeding, food deprivation, and cold exposure  

SciTech Connect

Thermogenesis in brown adipose tissue (BAT) serves as a regulator of body temperature and weight maintenance. Thermogenesis can be stimulated by catecholamine activation of adenylate cyclase through the {beta}-adrenergic receptor. To investigate the effects of sucrose feeding, food deprivation, and cold exposure on the {beta}-adrenergic pathway, adenylate cyclase activity and {beta}-adrenergic receptors were assessed in rat BAT after 2 wk of sucrose feeding, 2 days of food deprivation, or 2 days of cold exposure. {beta}-Adrenergic receptors were identified in BAT using ({sup 125}I)iodocyanopindolol. Binding sites had the characteristics of mixed {beta}{sub 1}- and {beta}{sub 2}-type adrenergic receptors at a ratio of 60/40. After sucrose feeding or cold exposure, there was the expected increase in BAT mitochondrial mass as measured by total cytochrome-c oxidase activity but a decrease in {beta}-adrenergic receptor density due to a loss of the {beta}{sub 1}-adrenergic subtype. This BAT {beta}-adrenergic receptor downregulation was tissue specific, since myocardial {beta}-adrenergic receptors were unchanged with either sucrose feeding or cold exposure. Forskolin-stimulated adenylate cyclase activity increased in BAT after sucrose feeding or cold exposure but not after food deprivation. These data suggest that in BAT, sucrose feeding or cold exposure result in downregulation of {beta}-adrenergic receptors and that isoproterenol-stimulated adenylate cyclase activity was limited by receptor availability.

Scarpace, P.J.; Baresi, L.A.; Morley, J.E. (Veterans Administration Medical Center, Los Angeles, CA (USA) Univ. of California, Los Angeles (USA))



Highly efficient synthesis of sucrose monolaurate by alkaline protease Protex 6L.  


An alkaline protease from Bacillus licheniformis, Protex 6L, was used for synthesis of sucrose monolaurate from sucrose and vinyl laurate in a tert-amyl alcohol/DMSO/water solvent mixture. Introducing sucrose as powder after mixing vinyl laurate with solvent mixture resulted in a higher reaction rate than when sucrose was added as a solution in DMSO. Response surface methodology (RSM) was applied to optimize the major reaction variables, water content, temperature and pH of the lyophilized enzyme. The optimal conditions derived from RSM (3.4% water content, 43 °C and pH of 10.1) provided a high initial reaction rate of 8.66 ± 0.3 mg/ml/h which agreed with the predicted value of 8.70 mg/ml/h. With 1.5 mg-enzyme/ml, 98.0% of the added sucrose was region-selectively converted to 1'-O-lauroylsucrose after 9h. Under the optimized conditions, Protex 6L exhibited a higher productivity for sucrose ester synthesis than Novozym 435 and three other commonly used enzymes. PMID:22305537

Wang, Xinran; Miao, Shida; Wang, Ping; Zhang, Songping



Networking proteins in yeast Tony R. Hazbun* and Stanley Fields  

E-print Network

of a reporter gene whose product is easily assayed, generally by growth of the yeast on a defined media. Ito et,000 predicted yeast proteins. They generated 62 pools of each type of yeast transformant, containing up to 96

Dunham, Maitreya


A Sucrose-derived Scaffold for Multimerization of Bioactive Peptides  

PubMed Central

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

Rao, Venkataramanarao; Alleti, Ramesh; Xu, Liping; Tafreshi, Narges K.; Morse, David L.; Gillies, Robert J.; Mash, Eugene A.



Sucrose Octasulfate Selectively Accelerates Thrombin Inactivation by Heparin Cofactor II*  

PubMed Central

Inactivation of thrombin (T) by the serpins heparin cofactor II (HCII) and antithrombin (AT) is accelerated by a heparin template between the serpin and thrombin exosite II. Unlike AT, HCII also uses an allosteric interaction of its NH2-terminal segment with exosite I. Sucrose octasulfate (SOS) accelerated thrombin inactivation by HCII but not AT by 2000-fold. SOS bound to two sites on thrombin, with dissociation constants (KD) of 10 ± 4 ?m and 400 ± 300 ?m that were not kinetically resolvable, as evidenced by single hyperbolic SOS concentration dependences of the inactivation rate (kobs). SOS bound HCII with KD 1.45 ± 0.30 mm, and this binding was tightened in the T·SOS·HCII complex, characterized by Kcomplex of ?0.20 ?m. Inactivation data were incompatible with a model solely depending on HCII·SOS but fit an equilibrium linkage model employing T·SOS binding in the pathway to higher order complex formation. Hirudin-(54–65)(SO3?) caused a hyperbolic decrease of the inactivation rates, suggesting partial competitive binding of hirudin-(54–65)(SO3?) and HCII to exosite I. Meizothrombin(des-fragment 1), binding SOS with KD = 1600 ± 300 ?m, and thrombin were inactivated at comparable rates, and an exosite II aptamer had no effect on the inactivation, suggesting limited exosite II involvement. SOS accelerated inactivation of meizothrombin 1000-fold, reflecting the contribution of direct exosite I interaction with HCII. Thrombin generation in plasma was suppressed by SOS, both in HCII-dependent and -independent processes. The ex vivo HCII-dependent process may utilize the proposed model and suggests a potential for oversulfated disaccharides in controlling HCII-regulated thrombin generation. PMID:20053992

Sarilla, Suryakala; Habib, Sally Y.; Kravtsov, Dmitri V.; Matafonov, Anton; Gailani, David; Verhamme, Ingrid M.



Drosophila Regulate Yeast Density and Increase Yeast Community Similarity in a Natural Substrate  

PubMed Central

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

Stamps, Judy A.; Yang, Louie H.; Morales, Vanessa M.; Boundy-Mills, Kyria L.



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.  


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

Volkert, Kathrin; Debast, Stefan; Voll, Lars M; Voll, Hildegard; Schießl, Ingrid; Hofmann, Jörg; Schneider, Sabine; Börnke, Frederik



Genome-wide interacting effects of sucrose and herbicide-mediated stress in Arabidopsis thaliana: novel insights into atrazine toxicity and sucrose-induced tolerance  

Microsoft Academic Search

BACKGROUND: Soluble sugars, which play a central role in plant structure and metabolism, are also involved in the responses to a number of stresses, and act as metabolite signalling molecules that activate specific or hormone-crosstalk transduction pathways. The different roles of exogenous sucrose in the tolerance of Arabidopsis thaliana plantlets to the herbicide atrazine and oxidative stress were studied by

Fanny Ramel; Cécile Sulmon; Francisco Cabello-Hurtado; Ludivine Taconnat; Marie-Laure Martin-Magniette; Jean-Pierre Renou; Abdelhak El Amrani; Ivan Couée; Gwenola Gouesbet



Yeast Breads: Made at Home.  

E-print Network

the bread. Sugar helps give a golden brown color to the crust. fat Some type of fat or oil is included in nearly all yeast bread. It conditions the gluten, making other ingredients Eggs give extra flavor and richness and s! to the food value.... They help produce a f~r delicate texture and a golden brown crust. Rn' and breads made with egg whites and \\\\a. usually have an open grain and a somewhat tila' crisp crust. For various kinds of fancy bre;l' and rolls, fruits, nuts, spices and other...

Reasonover, Frances



Yeast Breads: Made at Home.  

E-print Network

are developed by stirring and beating the batter I .-. combined and only enough flour is added to than by kneading. Batters are allowed tc make a thick batter. This batter is set in a warm either in the bowl or baking pan. Combining i ngre for bre rolls...- ing, since it is an accurate guide in keeping the correct temperature. Active dry yeast is dissolved in warm, not hot, water. The "feel" test may be used by experienced bread makers. Place a drop of liquid on the inside of the wrist. If the liquid...

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



The protein kinase SnRK2.6 mediates the regulation of sucrose metabolism and plant growth in Arabidopsis.  


In higher plants, three subfamilies of sucrose nonfermenting-1 (Snf1)-related protein kinases have evolved. While the Snf1-related protein kinase 1 (SnRK1) subfamily has been shown to share pivotal roles with the orthologous yeast Snf1 and mammalian AMP-activated protein kinase in modulating energy and metabolic homeostasis, the functional significance of the two plant-specific subfamilies SnRK2 and SnRK3 in these critical processes is poorly understood. We show here that SnRK2.6, previously identified as crucial in the control of stomatal aperture by abscisic acid (ABA), has a broad expression pattern and participates in the regulation of plant primary metabolism. Inactivation of this gene reduced oil synthesis in Arabidopsis (Arabidopsis thaliana) seeds, whereas its overexpression increased Suc synthesis and fatty acid desaturation in the leaves. Notably, the metabolic alterations in the SnRK2.6 overexpressors were accompanied by amelioration of those physiological processes that require high levels of carbon and energy input, such as plant growth and seed production. However, the mechanisms underlying these functionalities could not be solely attributed to the role of SnRK2.6 as a positive regulator of ABA signaling, although we demonstrate that this kinase confers ABA hypersensitivity during seedling growth. Collectively, our results suggest that SnRK2.6 mediates hormonal and metabolic regulation of plant growth and development and that, besides the SnRK1 kinases, SnRK2.6 is also implicated in the regulation of metabolic homeostasis in plants. PMID:20200070

Zheng, Zhifu; Xu, Xiaoping; Crosley, Rodney A; Greenwalt, Scott A; Sun, Yuejin; Blakeslee, Beth; Wang, Lizhen; Ni, Weiting; Sopko, Megan S; Yao, Chenglin; Yau, Kerrm; Burton, Stephanie; Zhuang, Meibao; McCaskill, David G; Gachotte, Daniel; Thompson, Mark; Greene, Thomas W



A rapid isotope dilution procedure for estimating the relative proportion of mitochondrial DNA in yeast.  


A method is described for estimating rapidly the relative proportion of total DNA that is of mitochondrial origin in small quantities of the yeast, Saccharomyces cerevisiae. This procedure involves the mechanical disruption of cells followed by the addition of small amounts of radioactively labeled yeast nuclear and mitochondrial DNA to the lysate. Both labeled and unlabeled DNAs are then co-extracted from the mixture and separated into nuclear and mitochondrial DNA components by poly(L-lysine) Kieselguhr column chromatography. The resulting specific radioactivities of each species of DNA, when compared to the amount of labeled DNA initially added, or related to the relative proportion of unlabeled nuclear and mitochondrial DNA in the original cell sample. The isotope dilution procedure reported here is shown to be both reproducible and to reflect the true relative concentration of each species of DNA in this yeast. PMID:7025913

Cottrell, S F



Can yeast transcriptomics help improve wine fermentation?  

Microsoft Academic Search

Wine fermentation is a dynamic and complex process in which the yeast cell is subjected to multiple stress conditions. A successful adaptation involves changes in gene expression profiles where a large number of genes are up- or down-regulated. Functional genomic approaches are com- monly used to obtain global gene expression profiles, providing a comprehensive view of yeast physiology. We used

C. Varela; J. Cárdenas; E. Agosin


Evolutionary constraints on yeast protein size  

Microsoft Academic Search

BACKGROUND: Despite a strong evolutionary pressure to reduce genome size, proteins vary in length over a surprisingly wide range also in very compact genomes. Here we investigated the evolutionary forces that act on protein size in the yeast Saccharomyces cerevisiae utilizing a system-wide bioinformatics approach. Data on yeast protein size was compared to global experimental data on protein expression, phenotypic

Jonas Warringer; Anders Blomberg



Fermentation studies using Saccharomyces diastaticus yeast strains  

SciTech Connect

The yeast species, Saccharomyces diastaticus, has the ability to ferment starch and dextrin, because of the extracellular enzyme, glucoamylase, which hydrolyzes the starch/dextrin to glucose. A number of nonallelic genes--DEX 1, DEX 2, and dextrinase B which is allelic to STA 3--have been isolated, which impart to the yeast the ability to ferment dextrin. Various diploid yeast strains were constructed, each being either heterozygous or homozygous for the individual dextrinase genes. Using 12 (sup 0) plato hopped wort (30% corn adjunct) under agitated conditions, the fermentation rates of the various diploid yeast strains were monitored. A gene-dosage effect was exhibited by yeast strains containing DEX 1 or DEX 2, however, not with yeast strains containing dextrinase B (STA 3). The fermentation and growth rates and extents were determined under static conditions at 14.4 C and 21 C. With all yeast strains containing the dextrinase genes, both fermentation and growth were increased at the higher incubation temperature. Using 30-liter fermentors, beer was produced with the various yeast strains containing the dextrinase genes and the physical and organoleptic characteristics of the products were determined. The concentration of glucose in the beer was found to increase during a 3-mo storage period at 21 C, indicating that the glucoamylase from Saccharomyces diastaticus is not inactivated by pasteurization. (Refs. 36).

Erratt, J.A.; Stewart, G.G.



Oily yeasts as oleaginous cell factories.  


Oily yeasts have been described to be able to accumulate lipids up to 20% of their cellular dry weight. These yeasts represent a minor proportion of the total yeast population, and only 5% of them have been reported as able to accumulate more than 25% of lipids. The oily yeast genera include Yarrowia, Candida, Rhodotorula, Rhodosporidium, Cryptococcus, Trichosporon, and Lipomyces. More specifically, examples of oleaginous yeasts include the species: Lipomyces starkeyi, Rhodosporidium toruloides, Rhodotorula glutinis, and Yarrowia lipolytica. Yeast do exhibit advantages for lipid production over other microbial sources, namely, their duplication times are usually lower than 1 h, are much less affected than plants by season or climate conditions, and their cultures are more easily scaled up than those of microalgae. Additionally, some oily yeasts have been reported to accumulate oil up to 80% of their dry weight and can indeed generate different lipids from different carbon sources or from lipids present in the culture media. Thus, they can vary their lipid composition by replacing the fatty acids present in their triglycerides. Due to the diversity of microorganisms and growth conditions, oily yeasts can be useful for the production of triglycerides, surfactants, or polyunsaturated fatty acids. PMID:21465305

Ageitos, Jose Manuel; Vallejo, Juan Andres; Veiga-Crespo, Patricia; Villa, Tomas G



Identification of yeasts isolated from poultry meat.  


In an assessment of the potential role of yeasts in the spoilage of poultry meat, the population and species diversity of yeasts were determined on 50 commercial raw and processed chicken and turkey product samples. Initial populations (log10 cfu/g) ranged from less than 0.1 to 2.9, and increased by the expiration date to 0.4 to 5.1, respectively. 145 of 152 isolates were identified as belonging to 12 species. Yarrowia lipolytica and Candida zeylanoides were predominant, accounting for 39% and 26% of the isolates, respectively. Six different species of basidiomycetous yeasts were determined representing 24% of the isolates. The ability of the predominant yeast species to grow at refrigeration temperatures and their proteolytic and lipolytic activies suggest that yeasts may play a more significant role than previously recognised in the spoilage of poultry products. PMID:11426853

Deák, T



Global nucleosome occupancy in yeast  

PubMed Central

Background Although eukaryotic genomes are generally thought to be entirely chromatin-associated, the activated PHO5 promoter in yeast is largely devoid of nucleosomes. We systematically evaluated nucleosome occupancy in yeast promoters by immunoprecipitating nucleosomal DNA and quantifying enrichment by microarrays. Results Nucleosome depletion is observed in promoters that regulate active genes and/or contain multiple evolutionarily conserved motifs that recruit transcription factors. The Rap1 consensus was the only binding motif identified in a completely unbiased search of nucleosome-depleted promoters. Nucleosome depletion in the vicinity of Rap1 consensus sites in ribosomal protein gene promoters was also observed by real-time PCR and micrococcal nuclease digestion. Nucleosome occupancy in these regions was increased by the small molecule rapamycin or, in the case of the RPS11B promoter, by removing the Rap1 consensus sites. Conclusions The presence of transcription factor-binding motifs is an important determinant of nucleosome depletion. Most motifs are associated with marked depletion only when they appear in combination, consistent with a model in which transcription factors act collaboratively to exclude nucleosomes and gain access to target sites in the DNA. In contrast, Rap1-binding sites cause marked depletion under steady-state conditions. We speculate that nucleosome depletion enables Rap1 to define chromatin domains and alter them in response to environmental cues. PMID:15345046

Bernstein, Bradley E; Liu, Chih Long; Humphrey, Emily L; Perlstein, Ethan O; Schreiber, Stuart L



Hydrothermal treatment of oleaginous yeast for the recovery of free fatty acids for use in advanced biofuel production.  


Microbial oils hold great potential as a suitable feedstock for the renewable production of biofuels. Specifically, the use of oleaginous yeasts offers several advantages related to cultivation and quality of lipid products. However, one of the major bottlenecks for large-scale production of yeast oils is found in the lipid extraction process. This work investigated the hydrothermal treatment of oleaginous yeast for hydrolysis and lipid extraction resulting in fatty acids used for biofuel production. The oleaginous yeast, Cryptococcus curvatus, was grown in 5L bioreactors and the biomass slurry with 53±4% lipid content (dry weight basis) was treated at 280°C for 1h with an initial pressure of 500psi in batch stainless steel reactors. The hydrolysis product was separated and each of the resulting streams was further characterized. The hexane soluble fraction contained fatty acids from the hydrolysis of yeast triacylglycerides, and was low in nitrogen and minerals and could be directly integrated as feedstock into pyrolysis processing to produce biofuels. The proposed hydrothermal treatment addresses some current technological bottlenecks associated with traditional methodologies such as dewatering, oil extraction and co-product utilization. It also enhances the feasibility of using microbial biomass for production of renewable fuels and chemicals. PMID:25034431

Espinosa-Gonzalez, Isabel; Parashar, Archana; Bressler, David C



In vitro and in vivo effects of standardized extract and fractions of Phaleria macrocarpa fruits pericarp on lead carbohydrate digesting enzymes  

PubMed Central

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?



The Structure of Sucrose Phosphate Synthase from Halothermothrix orenii Reveals Its Mechanism of Action and Binding Mode  

Microsoft Academic Search

Sucrose phosphate synthase (SPS) catalyzes the transfer of a glycosyl group from an activated donor sugar, such as uridine diphosphate glucose (UDP-Glc), to a saccharide acceptor D-fructose 6-phosphate (F6P), resulting in the formation of UDP and D-sucrose-6'-phosphate (S6P). This is a central regulatory process in the production of sucrose in plants, cyanobacteria, and proteobacteria. Here, we report the crystal structure

Teck Khiang Chua; Janusz M. Bujnicki; T.-C. Tan; F. Huynh; B. K. Patel; J. Sivaraman; Y. Ogimoto; K. Miyano; H. Sawa



Reexamination of the double sucrose gap technique for the study of lobster giant axons. Theory and experiments.  


The double sucrose gap technique for the study of lobster giant axons has been reexamined. The leakage behavior of the system cannot be successfully modeled by conventional sucrose gap theory, but is accounted for by the McGuigan-Tsien model that takes into account the cable properties of membrane under sucrose. The facts of high-leakage conductance and the ability to maintain large resting potentials in the face of low sucrose gap resistance lead to a hypothesis that membrane resistance under sucrose is very low because of a large negative surface potential. Computer simulations of the leakage behavior of the conventional gap model and the McGuigan-Tsien model were compared with experimental measurements on lobster axons using normal sucrose or sucrose doped with Na+, Ca2+ or La3+ ions. As the concentration of doping ion increased, the leakage rose, but the species of doping ion had more influence on leakage than gap resistance. At equal gap resistance, leakage decreased with an increase in valence of the doping species. Leakage was even lower in La-doped sucrose at 20 M omega gap resistance than in normal sucrose at 200 M omega gap resistance. Resting potentials decreased with decreasing gap resistance and increasing valence of the doping species. Resting potential behavior was successfully simulated with a hybrid model consisting of a point node flanked by infinite cables and a shunt between ground and the voltage-measuring pool. The data support the hypothesis that the membrane resistance under sucrose is low and that it can be raised by doping the sucrose with multivalent cations, with La3+ being particularly effective. Both the leak conductance and resting potential are influenced more by membrane under sucrose than membrane in the node. The experiments also demonstrate that doping with La3+ vastly improves the stability and longevity properties of the lobster axon preparation. PMID:6652217

Pooler, J P; Valenzeno, D P



Viscosity B-coefficients and activation parameters for viscous flow of a solution of heptanedioic acid in aqueous sucrose solution  

Microsoft Academic Search

Viscosity and density data for the system of heptanedioic acid dissolved in aqueous sucrose solution at temperature range from 288.15 to 313.15 K have been measured. The viscosity B-coefficients for heptanedioic acid in aqueous sucrose solution has been calculated. The effect of temperature and sucrose concentration on the B-coefficients is discussed. On the basis of the Feakins equation, the activation

Tong-Chun Bai; Guo-Bing Yan



Improved ethanol production from sucrose by a mutant of Zymomonas mobilis lacking sucrases in immobilized cell fermentation  

Microsoft Academic Search

Ethanol production from sucrose by Zymomonas mobilis LS1A, a mutant strain lacking levansucrase (SacB) and intracellular sucrase (SacA), was studied in an alginate-immobilized cell fermentation. Since this mutant strain does not produce levan from sucrose, the immobilized cells were stable in sucrose fermentations and therefore produced higher amounts of ethanol (73.5 g l?1) than that of its parent strain, B-806

T. R. Kannan; G. Sangiliyandi; P. Gunasekaran



The effects of co-lyophilized polymeric additives on the glass transition temperature and crystallization of amorphous sucrose  

Microsoft Academic Search

The purpose of this study was to measure the effect of co-lyophilized polymers on the crystallization of amorphous sucrose, and to test for a possible relationship between the ability of an additive to raise theTg of a sucrose-additive mixture, relative to theTg of pure sucrose, and its ability to inhibit crystallization. Differential scanning calorimetry was used to measure the glass

Sheri L. Shamblin; Eva Y. Huang; G. Zografi



Optimum production and characterization of an acid protease from marine yeast Metschnikowia reukaufii W6b  

NASA Astrophysics Data System (ADS)

The marine yeast strain W6b isolated from sediment of the South China Sea was found to produce a cell-bound acid protease. The crude acid protease produced by this marine yeast showed the highest activity at pH 3.5 and 40 °C. The optimal pH and temperature for the crude acid protease were in agreement with those for acid protease produced by the terrestrial yeasts. The optimal medium of the acid protease production was seawater containing 1.0% glucose, 1.5% casein, and 0.5% yeast extract, and the optimal cultivation conditions of the acid protease production were pH 4.0, a temperature of 25 °C and a shaking speed of 140 rmin-1. Under the optimal conditions, 72.5 UmL-1 of acid protease activity could be obtained in cell suspension within 48 h of fermentation at shake flask level. The acid protease production was induced by high-molecular-weight nitrogen sources and repressed by low-molecular-weight nitrogen sources. Skimmed-milk-clotting test showed that the crude acid protease from the cell suspension of the yeast W6b had high skimmed milk coagulability. The acid protease produced by M. reukaufii W6b may have highly potential applications in cheese, food and fermentation industries.

Li, Jing; Peng, Ying; Wang, Xianghong; Chi, Zhenming



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).  


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

Diedhiou, Calliste; Gaudet, Denis; Liang, Yehong; Sun, Jinyue; Lu, Zhen-Xing; Eudes, François; Laroche, André



Pharmaceutical characterization and thermodynamic stability assessment of a colloidal iron drug product: iron sucrose.  


The study objective was to evaluate the thermodynamic stability of iron sucrose complexes as determined by molecular weight (m.w.) changes. The first part of the study focused on the effect of thermal stress, pH, electrolyte or excipient dilution on the stability of a colloidal iron drug product. Part two focused on the physical and chemical evaluation of the colloidal nature of iron sucrose using a series of characterization experiments: ultracentrifugation, dialysis, particle size, zeta potential, and osmotic pressure analysis. A validated Taguchi-optimized high performance gel permeation chromatography method was used for m.w. determinations. Results indicate m.w. of the iron sucrose complex remained unchanged after excipient dilution, ultracentrifugation, dialysis, and electrolyte dilution. Electrolyte dilution studies indicated the lyophilic nature of the iron sucrose colloid with a particle size of 10nm and zeta potential of 0 mV. The complex deformed at low pH and reformed back at the formulation pH. The complex is stable under mild-to-moderate temperature <50°C but aggregates following prolonged exposure to high temperatures >70°C. In conclusion, the resistance of the complex to breakdown by electrolytic conditions, excipient dilution, ultracentrifugation and the reversible complexation after alteration of formulation pH suggest iron sucrose is a lyophilic colloid in nature and lyophilic colloidals are thermodynamically stable. PMID:24440404

Shah, Rakhi B; Yang, Yongsheng; Khan, Mansoor A; Raw, Andre; Yu, Lawrence X; Faustino, Patrick J



Postpartum depression in rats: differences in swim test immobility, sucrose preference and nurturing behaviors.  


Postpartum depression (PPD) is a common disorder affecting both mothers and their offspring. Studies of PPD in laboratory animals have typically assessed either immobility on forced swim testing or sucrose preference in ovariectomized rats following hormone supplementation and withdrawal or in stress models. To date, few studies have related these measures to maternal behaviors, a potential indicator of depressive-like activity postpartum. Because a single measure may be insufficient to characterize depression, the present study determined the distribution of depressive-like behaviors in Sprague-Dawley rats postpartum. Nurturing and non-nurturing behaviors exhibited by undisturbed dams were recorded during the first 12 days postpartum, and immobility in the forced swim test and sucrose preference were determined thereafter. A median-split analysis indicated that 19% of dams exhibited high sucrose preference and low immobility, 30% exhibited either only high immobility or only low sucrose preference, and 21% exhibited both high immobility and low preference. Dams exhibiting depressive-like activity on either or both tests displayed increased self-directed behaviors and decreased active nurturing during the dark phase of the diurnal cycle. This is the first study to characterize undisturbed nurturing and non-nurturing behaviors, and use both sucrose preference and immobility in the forced swim test, to classify PPD endophenotypes exhibited by rat dams following parturition. The present study underscores the idea that multiple tests should be used to characterize depressive-like behavior, which is highly heterogeneous in both the human and laboratory animal populations. PMID:24983658

Fernandez, Jamie Winderbaum; Grizzell, J Alex; Philpot, Rex M; Wecker, Lynn



Effects of selected polysorbate and sucrose ester emulsifiers on the physicochemical properties of astaxanthin nanodispersions.  


The effects of selected nonionic emulsifiers on the physicochemical characteristics of astaxanthin nanodispersions produced by an emulsification/evaporation technique were studied. The emulsifiers used were polysorbates (Polysorbate 20, Polysorbate 40, Polysorbate 60 and Polysorbate 80) and sucrose esters of fatty acids (sucrose laurate, palmitate, stearate and oleate). The mean particle diameters of the nanodispersions ranged from 70 nm to 150 nm, depending on the emulsifier used. In the prepared nanodispersions, the astaxanthin particle diameter decreased with increasing emulsifier hydrophilicity and decreasing carbon number of the fatty acid in the emulsifier structure. Astaxanthin nanodispersions with the smallest particle diameters were produced with Polysorbate 20 and sucrose laurate among the polysorbates and the sucrose esters, respectively. We also found that the Polysorbate 80- and sucrose oleate-stabilized nanodispersions had the highest astaxanthin losses (i.e., the lowest astaxanthin contents in the final products) among the nanodispersions. This work demonstrated the importance of emulsifier type in determining the physicochemical characteristics of astaxanthin nano-dispersions. PMID:23303336

Anarjan, Navideh; Tan, Chin Ping



Time-dependent dissociation of cocaine dose-response effects on sucrose craving and locomotion  

PubMed Central

In the present study, rats self-administered sucrose 6 h/day for 10 days. Separate groups of rats were then tested on day 1 or day 30 of forced abstinence. After they had responded to near extinction, rats were injected with either saline or cocaine (2.5, 5, 10, or 20 mg/kg intraperitoneal) and then allowed to respond to a sucrose-paired stimulus. Locomotor activity was assessed during testing. Rats pressed more during the extinction responding phase of testing on day 30 than on day 1 of forced abstinence, and this incubation of craving was accompanied by a time-dependent increase in locomotor activity. Compared with saline, cocaine increased responding for the sucrose-paired cue on day 1 of forced abstinence at the 5 mg/kg dose only. In contrast, responding on day 30 was increased at the 10 and 20 mg/kg doses. Locomotor activity increased dose-dependently at both forced-abstinence time points, suggesting a dissociation between cocaine-induced locomotion and cocaine-elevated responding for a sucrose-paired stimulus. These results also indicate that there are time-dependent changes in how cocaine affects sucrose craving. PMID:16495722

Grimm, Jeffrey W.; Buse, Carl; Manaois, Meghan; Osincup, Dan; Fyall, Amber; Wells, Barbara



Environmental enrichment attenuates cue-induced reinstatement of sucrose seeking in rats  

PubMed Central

This study examined the effect of environmental enrichment on sucrose seeking in rats made abstinent from sucrose for 1 month, as measured by response for a tone + light cue previously associated with 10% sucrose self-administration. Rats were either enriched throughout the study (experiment 1) or only after sucrose self-administration training (experiment 2). Enrichment consisted of either housing the rats in pairs or grouping four rats (ENR4) in a large environment, both with novel objects. Controls (CON) were singly housed without novel objects. In experiment 1, ENR4 rats responded less to the sucrose-paired cue versus CON rats, but this difference was not statistically significant. In contrast, the decrease in response of ENR4 rats versus CON rats in experiment 2 was dramatic and significant. These findings, along with findings from other laboratories, support a hypothesis that the enrichment may provide individuals with a greater ability to discriminate the availability of reward. This may impart a decreased vulnerability to relapse behavior. Therefore, these results are relevant to both eating disorder and drug addiction – disorders characterized by relapse. PMID:19020412

Grimm, Jeffery W.; Osincup, Daniel; Wells, Barbara; Manaois, Meghan; Fyall, Amber; Buse, Carl; Harkness, John H.



Effect of Diet on Preference and Intake of Sucrose in Obese Prone and Resistant Rats  

PubMed Central

Increased orosensory stimulation from palatable diets and decreased feedback from gut signals have been proposed as contributing factors to obesity development. Whether altered taste functions associated with obesity are common traits or acquired deficits to environmental factors, such as a high-energy (HE)-diet, however, is not clear. To address this, we examined preference and sensitivity of increasing concentrations of sucrose solutions in rats prone (OP) and resistant (OR) to obesity during chow and HE feeding and measured lingual gene expression of the sweet taste receptor T1R3. When chow-fed, OP rats exhibited reduced preference and acceptance of dilute sucrose solutions, sham-fed less sucrose compared to OR rats, and had reduced lingual T1R3 gene expression. HE-feeding abrogated differences in sucrose preference and intake and lingual T1R3 expression between phenotypes. Despite similar sucrose intakes however, OP rats consumed significantly more total calories during 48-h two-bottle testing compared to OR rats. The results demonstrate that OP rats have an innate deficit for sweet taste detection, as illustrated by a reduction in sensitivity to sweets and reduced T1R3 gene expression; however their hyperphagia and subsequent obesity during HE-feeding is most likely not due to altered consumption of sweets. PMID:25329959

Duca, Frank A.; Swartz, Timothy D.; Covasa, Mihai



Effect of diet on preference and intake of sucrose in obese prone and resistant rats.  


Increased orosensory stimulation from palatable diets and decreased feedback from gut signals have been proposed as contributing factors to obesity development. Whether altered taste functions associated with obesity are common traits or acquired deficits to environmental factors, such as a high-energy (HE)-diet, however, is not clear. To address this, we examined preference and sensitivity of increasing concentrations of sucrose solutions in rats prone (OP) and resistant (OR) to obesity during chow and HE feeding and measured lingual gene expression of the sweet taste receptor T1R3. When chow-fed, OP rats exhibited reduced preference and acceptance of dilute sucrose solutions, sham-fed less sucrose compared to OR rats, and had reduced lingual T1R3 gene expression. HE-feeding abrogated differences in sucrose preference and intake and lingual T1R3 expression between phenotypes. Despite similar sucrose intakes however, OP rats consumed significantly more total calories during 48-h two-bottle testing compared to OR rats. The results demonstrate that OP rats have an innate deficit for sweet taste detection, as illustrated by a reduction in sensitivity to sweets and reduced T1R3 gene expression; however their hyperphagia and subsequent obesity during HE-feeding is most likely not due to altered consumption of sweets. PMID:25329959

Duca, Frank A; Swartz, Timothy D; Covasa, Mihai



High Fat and High Sucrose (Western) Diet Induce Steatohepatitis that is Dependent on Fructokinase  

PubMed Central

Fructose intake from added sugars has been implicated as a cause of nonalcoholic fatty liver disease. Here we tested the hypothesis that fructose may interact with high fat diet to induce fatty liver, and to determine if this was dependent on a key enzyme in fructose metabolism, fructokinase. Wild type or fructokinase knockout mice were fed a low fat (11%), high fat (36%) or high fat (36%) and high sucrose (30%) diet for 15 weeks. Both wild type and fructokinase knockout mice developed obesity with mild hepatic steatosis and no evidence for hepatic inflammation on a high fat diet compared to a low fat diet. In contrast, wild type mice fed a high fat and high sucrose diet developed more severe hepatic steatosis with low grade inflammation and fibrosis, as noted by increased CD68, TNF-alpha, MCP-1, alpha-smooth muscle actin, and collagen I and TIMP1 expression. These changes were prevented in the fructokinase knockout mice. Conclusion An additive effect of high fat and high sucrose diet on the development of hepatic steatosis exists. Further, the combination of sucrose with high fat diet may induce steatohepatitis. The protection in fructokinase knockout mice suggests a key role for fructose (from sucrose) in this development of steatohepatitis. These studies emphasize the important role of fructose in the development of fatty liver and nonalcoholic steatohepatitis (NASH). PMID:23813872

Ishimoto, Takuji; Lanaspa, Miguel A.; Rivard, Christopher J.; Roncal-Jimenez, Carlos A.; Orlicky, David J.; Cicerchi, Christina; McMahan, Rachel H.; Abdelmalek, Manal F.; Rosen, Hugo R.; Jackman, Matthew R.; MacLean, Paul S.; Diggle, Christine P.; Asipu, Aruna; Inaba, Shinichiro; Kosugi, Tomoki; Sato, Waichi; Maruyama, Shoichi; Sanchez-Lozada, Laura G.; Sautin, Yuri Y.; Hill, James O.; Bonthron, David T.; Johnson, Richard J.



Impact of weighting agents and sucrose on gravitational separation of beverage emulsions.  


The influence of weighting agents and sucrose on gravitational separation in 1 wt % oil-in-water emulsions was studied by measuring changes in the intensity of backscattered light from the emulsions with height. Emulsions with different droplet densities were prepared by mixing weighting agents [brominated vegetable oil (BVO), ester gum (EG), damar gum (DG), or sucrose acetate isobutyrate (SAIB)] with soybean oil prior to homogenization. Sedimentation or creaming occurred when the droplet density was greater than or lower than the aqueous phase density, respectively. The weighting agent concentrations required to match the oil and aqueous phase densities were 25 wt % BVO, 55 wt % EG, 55 wt % DG, and 45 wt % SAIB. The efficiency of droplet reduction during homogenization also depended on weighting agent type (BVO > SAIB > DG, EG) due to differences in oil phase viscosity. The influence of sucrose (0-13 wt %) on the creaming stability of 1 wt % soybean oil-in-water emulsions was also examined. Sucrose increased the aqueous phase viscosity (retarding creaming) and increased the density contrast between droplets and aqueous phase (accelerating creaming). These two effects largely canceled one another so that the creaming stability was relatively insensitive to sucrose concentration. PMID:11087519

Chanamai, R; McClements, D J



Iron Sucrose Accelerates Early Atherogenesis by Increasing Superoxide Production and Upregulating Adhesion Molecules in CKD.  


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

Kuo, Ko-Lin; Hung, Szu-Chun; Lee, Tzong-Shyuan; Tarng, Der-Cherng



Presence and changes in populations of yeasts on raw and processed poultry products stored at refrigeration temperature.  


A study was undertaken to determine populations and profiles of yeast species on fresh and processed poultry products upon purchase from retail supermarkets and after storage at 5 degrees C until shelf life expiration, and to assess the potential role of these yeasts in product spoilage. Fifty samples representing 15 commercial raw, marinated, smoked, or roasted chicken and turkey products were analyzed. Yeast populations were determined by plating on dichloran rose bengal chloramphenicol (DRBC) agar and tryptone glucose yeast extract (TGY) agar. Proteolytic activity was determined using caseinate and gelatin agars and lipolytic activity was determined on plate count agar supplemented with tributyrin. Populations of aerobic microorganisms were also determined. Initial populations of yeasts (log10 cfu/g) ranged from less than 1 (detection limit) to 2.89, and increased by the expiration date to 0.37-5.06, indicating the presence of psychrotrophic species. Highest initial populations were detected in raw chicken breast, wings, and ground chicken, as well as in turkey necks and legs, whereas roasted chicken and turkey products contained less than 1 log10 cfu/g. During storage, yeast populations increased significantly (P < or = 0.05) in whole chicken, ground chicken, liver, heart and gizzard, and in ground turkey and turkey sausage. Isolates (152 strains) of yeasts from poultry products consisted of 12 species. Yarrowia lipolytica and Candida zeylanoides were predominant, making up 39 and 26% of the isolates, respectively. Six different species of basidiomycetous yeasts representing 24% of the isolates were identified. Most Y. lipolytica strains showed strong proteolytic and lipolytic activities, whereas C. zeylanoides was weakly lipolytic. Results suggest that yeasts, particularly Y. lipolytica, may play a more prominent role than previously recognized in the spoilage of fresh and processed poultry stored at 5 degrees C. PMID:11139011

Ismail, S A; Deak, T; El-Rahman, H A; Yassien, M A; Beuchat, L R



A complete assignment of the vibrational spectra of sucrose in aqueous medium based on the SQM methodology and SCRF calculations.  


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

Brizuela, Alicia Beatriz; Castillo, María Victoria; Raschi, Ana Beatriz; Davies, Lilian; Romano, Elida; Brandán, Silvia Antonia



Partitioning and transport of the translocates mannitol and sucrose in the light and dark in celery (Apium Graveolens L. )  

SciTech Connect

Sucrose and mannitol are major photosynthetic products and translocates in celery. Assimilate partitioning and transport were studied by pulse-labeling leaves with /sup 14/CO/sub 2/ followed by different length chases in ambient air. After a 2 h chase in the light there was more /sup 14/C in sucrose than mannitol in source leaves and their petioles. In contrast after a 2 h dark chase leaves contained more /sup 14/C in mannitol than sucrose but petioles had more /sup 14/C in sucrose than mannitol. After a 15 h chase (6 h light; 9 h dark) labeled sucrose was higher in source petiole vascular bundles than in adjacent parenchyma tissue but label in glucose and fructose was higher in the parenchyma tissue. After the 15 h chase most of the /sup 14/C remaining in developing sink leaves and their petioles was in mannitol. Although in the light mannitol:sucrose ratios are the same in leaf and petiole tissues, in the dark sucrose is initially the major translocate with mannitol becoming more important as leaf sucrose pools are depleted. When synthesized, sucrose is rapidly transported and then metabolized to hexose sugars whereas mannitol is used both for transport and storage.

Davis, J.M.; Loescher, W.H.




PubMed Central

Rats and humans avidly consume flavored foods that contain sucrose and fat, presumably due to their rewarding qualities. In this study, we hypothesized that the complex mixture of corn oil, sucrose, and flavor is more reinforcing than any of these components alone. We observed a concentration-dependent increase in reinforcers received of sucrose solutions (0, 3, 6.25, and 12.5%) in both fixed ratio and progressive ratio procedures, but with equicaloric corn oil solutions (0, 1.4, 2.8, and 5.6%) this finding was replicated only in the fixed ratio procedure. Likewise, addition of 1.4% oil to 3% or 12.5% sucrose increased fixed ratio, but not progressive ratio, reinforcers received relative to those of sucrose alone. Finally, addition of 3% vanilla flavoring did not change self-administration of 3% sucrose or 3% sucrose + 1.4% oil solutions. These data suggest that, calorie-for-calorie, sucrose is the dominant reinforcing component of novel foods that contain a mixture of fat, sucrose, and flavor. PMID:17707949

Naleid, Amy M.; Grimm, Jeffrey W.; Kessler, David A.; Sipols, Alfred J.; Aliakbari, Sepideh; Bennett, Jennifer L.; Wells, Jason; Figlewicz, Dianne P.



Antiestrogenic and antigenotoxic activity of bee pollen from Cystus incanus and Salix alba as evaluated by the yeast estrogen screen and the micronucleus assay in human lymphocytes  

Microsoft Academic Search

The estrogenic\\/antiestrogenic activity and the genotoxicity\\/antigenotoxicity of bee pollen from Salix alba L. and Cystus incanus L. and its derivative extracts in yeast and human cells was investigated. All samples showed a marked inhibitory effect on the activity of the natural estrogen 17 ?-estradiol (higher than 90% for extracts 2) and failed to cause estrogenic activity and chromosome damage. At

Barbara Pinto; Francesca Caciagli; Elisabetta Riccio; Daniela Reali; Ana Šari?; Tihomir Balog; Saša Liki?; Roberto Scarpato



Use of several waste substrates for carotenoid-rich yeast biomass production.  


Carotenoids are industrially significant pigments produced in many bacteria, fungi, and plants. Carotenoid biosynthesis in yeasts is involved in stress response mechanisms. Thus, controlled physiological and nutrition stress can be used for enhanced pigment production. Huge commercial demand for natural carotenoids has focused attention on developing of suitable biotechnological techniques including use of liquid waste substrates as carbon and/or nitrogen source. In this work several red yeast strains (Sporobolomyces roseus, Rhodotorula glutinis, Rhodotorula mucilaginosa) were enrolled into a comparative screening study. To increase the yield of these pigments at improved biomass production, several types of exogenous as well as nutrition stress were tested. Each strain was cultivated at optimal growth conditions and in medium with modified carbon and nitrogen sources. Synthetic media with addition of complex substrates (e.g. yeast extract) and vitamin mixtures as well as some waste materials (whey, potato extract) were used as nutrient sources. Peroxide and salt stress were applied too. The production of carotene enriched biomass was carried out in flasks as well as in laboratory fermentor. The best production of biomass was obtained in inorganic medium with yeast extract. In optimal conditions tested strains differ only slightly in biomass production. All strains were able to use most of waste substrates. Biomass and pigment production was more different according to substrate type. In laboratory fermentor better producers of enriched biomass were both Rhodotorula strains. The highest yields were obtained in R. glutinis CCY 20-2-26 cells cultivated on whey medium (cca 45 g per liter of biomass enriched by 46 mg/L of beta-carotene) and in R. mucilaginosa CCY 20-7-31 grown on potato medium and 5% salt (cca 30 g per liter of biomass enriched by 56 mg/L of beta-carotene). Such dried carotenoid-enriched red yeast biomass could be directly used in feed industry as nutrition supplement. PMID:21741756

Marova, I; Carnecka, M; Halienova, A; Certik, M; Dvorakova, T; Haronikova, A



Accelerating Yeast Prion Biology using Droplet Microfluidics  

NASA Astrophysics Data System (ADS)

Prions are infectious proteins in a misfolded form, that can induce normal proteins to take the misfolded state. Yeast prions are relevant, as a model of human prion diseases, and interesting from an evolutionary standpoint. Prions may also be a form of epigenetic inheritance, which allow yeast to adapt to stressful conditions at rates exceeding those of random mutations and propagate that adaptation to their offspring. Encapsulation of yeast in droplet microfluidic devices enables high-throughput measurements with single cell resolution, which would not be feasible using bulk methods. Millions of populations of yeast can be screened to obtain reliable measurements of prion induction and loss rates. The population dynamics of clonal yeast, when a fraction of the cells are prion expressing, can be elucidated. Furthermore, the mechanism by which certain strains of bacteria induce yeast to express prions in the wild can be deduced. Integrating the disparate fields of prion biology and droplet microfluidics reveals a more complete picture of how prions may be more than just diseases and play a functional role in yeast.

Ung, Lloyd; Rotem, Assaf; Jarosz, Daniel; Datta, Manoshi; Lindquist, Susan; Weitz, David



Computational Predictions of Structures of Multichromosomes of Budding Yeast  

E-print Network

Computational Predictions of Structures of Multichromosomes of Budding Yeast (Accepted, Conf Proc of budding yeast nucleus. We successfully generated a large number of model genomes of yeast with appropriate yeast genome realistically. The model developed here provides a general computational framework

Liang, Jie


Yeast (in press) Published online in Wiley InterScience  

E-print Network

Yeast Yeast (in press) Published online in Wiley InterScience ( DOI: 10.1002/yea.1502 Yeast Functional Analysis Report A suite of Gateway cloning vectors for high of overexpression plasmids containing the entire complement of yeast open reading frames (ORFs) have recently been

Lycan, Deborah E.


Original article Screening for the potential probiotic yeast strains  

E-print Network

Original article Screening for the potential probiotic yeast strains from raw milk to assimilate yeast strains, isolated from raw milk, were tested to obtain potential probiotic yeasts for assimilating cholesterol. During in vitro tests, 17 yeast strains were capable of growth in bile salt solutions, and most

Paris-Sud XI, Université de


Original article Effect of a viable yeast culture on digestibility  

E-print Network

cultures to improve productivity in livestock husbandry. In comparison with antimicrobial agents, yeast that the effect of yeast culture on ru- men fermentation may depend on the nature of.the diet. Living yeast cell culture offers a natural alternative to manipulate animal performance. Positive effects of a yeast culture

Boyer, Edmond