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1

Evidence for the Role of Calcineurin in Morphogenesis and Calcium Homeostasis during Mycelium-to-Yeast Dimorphism of Paracoccidioides brasiliensis  

Microsoft Academic Search

Paracoccidioides brasiliensis is a dimorphic fungus that causes paracoccidioidomycosis, the most prevalent human deep mycosis in Latin America. The dimorphic transition from mycelium to yeast (M-Y) is triggered by a temperature shift from 25°C to 37°C and is critical for pathogenicity. Intracellular Ca2 levels increased in hyphae immediately after temperature-induced dimorphism. The chelation of Ca2 with extracellular (EGTA) or intracellular

Claudia B. L. Campos; J. P. T. Di Benedette; F. V. Morais; R. Ovalle; M. P. Nobrega

2008-01-01

2

Differential PbP27 expression in the yeast and mycelial forms of the Paracoccidioides brasiliensis species complex.  

PubMed

p27 is an antigenic protein produced by Paracoccidioides brasiliensis, the etiologic agent of paracoccidioidomycosis (PCM). Despite its unknown function, it has been suggested as a putative virulence factor, proposed as a suitable target for the design of diagnostic tools and vaccines, and considered as an enhancer in antifungal treatment of PCM. We evaluated sequence polymorphisms of PbP27 gene sequence among isolates, finding some polymorphisms associated with the isolates' phylogenetic origin. In order to determine if there was a differential expression pattern between morphological states and among isolates, we also evaluated PbP27 expression, at transcriptional and translational levels, in mycelia and yeast cultures in 14 isolates belonging to the P. brasiliensis species complex (S1, PS2, PS3, and "Pb01-like", proposed to be named Paracoccidioides lutzii) by two techniques, real time RT-PCR (RT-qPCR) and protein dot blot. For the latter, four protein extracts from different cell localizations (SDS or ?-mercaptoethanol, cytoplasmic and extracellular proteins) were analyzed for each isolate. p27 was present in the four extracts evaluated, mainly in the SDS extract, corresponding to an extract containing proteins loosely attached to the cell wall. This information correlates with immunohistochemical analysis, where positive staining of the yeasts' cell wall was observed. We found that p27 was present in all isolates, mainly in the yeast form. This pattern was corroborated by RT-qPCR results, with higher expression levels found in the yeast form for most of the isolates. The results provide new insights into the expression patterns of this protein, and further characterize it in view of potential uses as a diagnostic and/or therapeutic tool. PMID:21945996

García Blanco, S; Muñoz, J F; Torres, I; Díez Posada, S; Gómez, B L; McEwen, J G; Restrepo, S; García, A M

2011-12-01

3

Evidence for the Role of Calcineurin in Morphogenesis and Calcium Homeostasis during Mycelium-to-Yeast Dimorphism of Paracoccidioides brasiliensis?  

PubMed Central

Paracoccidioides brasiliensis is a dimorphic fungus that causes paracoccidioidomycosis, the most prevalent human deep mycosis in Latin America. The dimorphic transition from mycelium to yeast (M-Y) is triggered by a temperature shift from 25°C to 37°C and is critical for pathogenicity. Intracellular Ca2+ levels increased in hyphae immediately after temperature-induced dimorphism. The chelation of Ca2+ with extracellular (EGTA) or intracellular (BAPTA) calcium chelators inhibited temperature-induced dimorphism, whereas the addition of extracellular Ca2+ accelerated dimorphism. The calcineurin inhibitor cyclosporine A (CsA), but not tacrolimus (FK506), effectively decreased cell growth, halted the M-Y transition that is associated with virulence, and caused aberrant growth morphologies for all forms of P. brasiliensis. The difference between CsA and FK506 was ascribed by the higher levels of cyclophilins contrasted to FKBPs, the intracellular drug targets required for calcineurin suppression. Chronic exposure to CsA abolished intracellular Ca2+ homeostasis and decreased mRNA transcription of the CCH1 gene for the plasma membrane Ca2+ channel in yeast-form cells. CsA had no detectable effect on multidrug resistance efflux pumps, while the effect of FK506 on rhodamine excretion was not correlated with the transition to yeast form. In this study, we present evidence that Ca2+/calmodulin-dependent phosphatase calcineurin controls hyphal and yeast morphology, M-Y dimorphism, growth, and Ca2+ homeostasis in P. brasiliensis and that CsA is an effective chemical block for thermodimorphism in this organism. The effects of calcineurin inhibitors on P. brasiliensis reinforce the therapeutic potential of these drugs in a combinatory approach with antifungal drugs to treat endemic paracoccidioidomycosis. PMID:18776037

Campos, Claudia B. L.; Di Benedette, Joao Paulo T.; Morais, Flavia V.; Ovalle, Rafael; Nobrega, Marina P.

2008-01-01

4

Cell organisation, sulphur metabolism and ion transport-related genes are differentially expressed in Paracoccidioides brasiliensis mycelium and yeast cells  

PubMed Central

Background Mycelium-to-yeast transition in the human host is essential for pathogenicity by the fungus Paracoccidioides brasiliensis and both cell types are therefore critical to the establishment of paracoccidioidomycosis (PCM), a systemic mycosis endemic to Latin America. The infected population is of about 10 million individuals, 2% of whom will eventually develop the disease. Previously, transcriptome analysis of mycelium and yeast cells resulted in the assembly of 6,022 sequence groups. Gene expression analysis, using both in silico EST subtraction and cDNA microarray, revealed genes that were differential to yeast or mycelium, and we discussed those involved in sugar metabolism. To advance our understanding of molecular mechanisms of dimorphic transition, we performed an extended analysis of gene expression profiles using the methods mentioned above. Results In this work, continuous data mining revealed 66 new differentially expressed sequences that were MIPS(Munich Information Center for Protein Sequences)-categorised according to the cellular process in which they are presumably involved. Two well represented classes were chosen for further analysis: (i) control of cell organisation – cell wall, membrane and cytoskeleton, whose representatives were hex (encoding for a hexagonal peroxisome protein), bgl (encoding for a 1,3-?-glucosidase) in mycelium cells; and ags (an ?-1,3-glucan synthase), cda (a chitin deacetylase) and vrp (a verprolin) in yeast cells; (ii) ion metabolism and transport – two genes putatively implicated in ion transport were confirmed to be highly expressed in mycelium cells – isc and ktp, respectively an iron-sulphur cluster-like protein and a cation transporter; and a putative P-type cation pump (pct) in yeast. Also, several enzymes from the cysteine de novo biosynthesis pathway were shown to be up regulated in the yeast form, including ATP sulphurylase, APS kinase and also PAPS reductase. Conclusion Taken together, these data show that several genes involved in cell organisation and ion metabolism/transport are expressed differentially along dimorphic transition. Hyper expression in yeast of the enzymes of sulphur metabolism reinforced that this metabolic pathway could be important for this process. Understanding these changes by functional analysis of such genes may lead to a better understanding of the infective process, thus providing new targets and strategies to control PCM. PMID:16907987

Andrade, Rosangela V; Paes, Hugo C; Nicola, Andre M; de Carvalho, Maria Jose A; Fachin, Ana Lucia; Cardoso, Renato S; Silva, Simoneide S; Fernandes, Larissa; Silva, Silvana P; Donadi, Eduardo A; Sakamoto-Hojo, Elza T; Passos, Geraldo AS; Soares, Celia MA; Brigido, Marcelo M; Felipe, Maria Sueli S

2006-01-01

5

Molecular detection and identification of Paracoccidioides brasiliensis.  

PubMed Central

Nearly 800 nucleotides from the 5' terminus of the 28S ribosomal gene of Paracoccidioides brasiliensis were sequenced, and a 14-base DNA probe specific for this species was identified. Hybridization results showed that the probe identified P. brasiliensis ribosomal DNA in a panel of ribosomal DNAs representing a total of 48 species of fungi. PMID:9196219

Sandhu, G S; Aleff, R A; Kline, B C; da Silva Lacaz, C

1997-01-01

6

Identification of Paracoccidioides brasiliensis by gold nanoprobes  

NASA Astrophysics Data System (ADS)

Paracoccidioides brasiliensis (P. brasiliensis) is a thermal dimorphic fungus and causal agent of paracoccidioidomycosis. Epidemiological data shows that it is mainly concentrated in Central and South America countries, with most registered cases in Colombia, Brazil, and Venezuela. The histopathological similarity with others fungal infection makes the diagnosis of P. brasiliensis more complicated. Therefore, the aim of this work was to find a positive and negative test for P. brasiliensis using gold nanoprobes as a new tool for P. brasiliensis detection. Gold nanoparticles were synthesized by reduction of gold chloride with sodium citrate. The results of this procedure is a wine-red solution with a maximum absorption in the range of ~520-530nm. A specific P. brasiliensis sequence of oligonucleotide was bonded to the nanoparticles, which maintained the wine-red color. The color changes from red to blue for negative diagnostic and is unchanged for a positive test. The H-bond interaction of DNA with the complementary DNA keeps strands together and forms double helical structure, maintaining the colloid stability. However, for non-complimentary DNA sequence the nanoprobes merge into a cluster, changing the light absorption.

Martins, Jaciara F. S.; Castilho, Maiara L.; Cardoso, Maria A. G.; Carreiro, Andrea P.; Martin, Airton A.; Raniero, Leandro

2012-01-01

7

Transcriptome overview of Paracoccidioides brasiliensis proteases.  

PubMed

Proteases perform a wide variety of functions inside and outside cells, regulating many biological processes. Infectious microorganisms use proteases, either secreted or attached to their cell surface to weaken and invade their hosts. Therefore, proteases are targets for drugs against a diverse set of diseases. Paracoccidioides brasiliensis is the most prevalent fungal pathogen causing systemic mycosis in Latin America. The development of paracoccidioidomycosis depends on interactions between fungal and host components and proteases have been described as important factors implicated in the mechanism of host colonization by fungi. The primary goal for this study is to present an overview of the transcriptome sequences--identified cDNAs that encode proteases. We obtained a total of 53 cDNAs encoding proteases; 15 were classified as ATP-independent, 12 as ATP-dependent, 22 as proteasome subunits, and 4 as deubiquitinating proteases. The mechanisms and biological activity of these proteases differ in substrate specificity and in catalytic mechanisms. PMID:16110451

Parente, Juliana Alves; Costa, Milce; Pereira, Maristela; Soares, Célia Maria de Almeida

2005-01-01

8

Hygromycin B-resistance phenotype acquired in Paracoccidioides brasiliensis via plasmid DNA integration.  

PubMed

Yeast cells of the human pathogenic fungus Paracoccidioides brasiliensis strain Pb01 were transformed to hygromycin B resistance using the plasmid pAN7.1. Transformation was achieved by electroporation, with intact or linearized plasmid DNA. The fungus was transformed using 200 mM manitol, 5 or 7 kV/cm field strength, 25 microF capacitance, 400 omega resistance, 5 microg plasmid DNA and 10(7) yeast cells in 400 microl, and selected in BHI medium overlaid with 30 microg/ml hygromycin B (hygB). Mitotic stability was assessed by growing transformants on non-selective BHI medium, followed by plating on hygromycin B (30 microg/ml). Transformants were analyzed by PCR and Southern blotting, confirming the hph gene integration into the transformants genome. A low level of stability of the integrated hph sequence in the transformant genomes was observed, probably because of the multinuclearity of P. brasiliensis yeast cells. PMID:16422302

Soares, Renata De B A; Velho, Tarcísio A F; De Moraes, Lidia M P; Azevedo, Maristela O; Soares, Célia M De A; Felipe, Maria Sueli S

2005-12-01

9

Gene expression modulation by paraquat-induced oxidative stress conditions in Paracoccidioides brasiliensis.  

PubMed

Paracoccidioides brasiliensis is a thermodimorphic fungus associated with paracoccidioidomycosis (PCM), the most common systemic mycosis in Latin America. The infection is initiated by inhalation of environmentally dispersed conidia produced by the saprophytic phase of the fungus. In the lungs, P. brasiliensis assumes the parasitic yeast form and must cope with the adverse conditions imposed by cells of the host immune system, which includes a harsh environment, highly concentrated in reactive oxygen species (ROS). In this work, we used the ROS-generating agent paraquat to experimentally simulate oxidative stress conditions in order to evaluate the stress-induced modulation of gene expression in cultured P. brasiliensis yeast cells, using a microarray hybridization approach. The large-scale evaluation inherent to microarray-based analyses identified 2070 genes differentially transcribed in response to paraquat exposure, allowing an integrated visualization of the major metabolic changes that constitute the systemic defense mechanism used by the fungus to overcome the deleterious effects of ROS. These include overexpression of detoxifying agents, as well as of molecular scavengers and genes involved in maintenance of the intracellular redox potential. Particularly noteworthy was to verify that the oxidative stress resistance mechanism of P. brasiliensis also involves coordinated overexpression of a series of genes responsible for chitin-biosynthesis, suggesting that this pathway may constitute a specific regulon. Further analyses aiming at confirming and understanding the mechanisms that control such regulon may provide interesting new targets for chemotherapeutic approaches against P. brasiliensis and other pathogenic fungi. PMID:23711636

de Oliveira, Marcus Vinícius; Oliveira, Ana Claudia de Freitas; Shida, Cláudio S; de Oliveira, Regina Costa; Nunes, Luiz R

2013-11-01

10

Morphological heterogeneity of Paracoccidioides brasiliensis: relevance of the Rho-like GTPase PbCDC42.  

PubMed

Paracoccidioides brasiliensis budding pattern and polymorphic growth were previously shown to be closely linked to the expression of PbCDC42 and to influence the pathogenesis of the fungus. In this work we conducted a detailed morphogenetic evaluation of the yeast-forms of 11 different clinical and environmental P. brasiliensis isolates comprising four phylogenetic lineages (S1, PS2, PS3 and Pb01-like), as well as a PbCDC42 knock-down strain. High variations in the shape and size of mother and bud cells of each isolate were observed but we did not find a characteristic morphologic profile for any of the phylogenetic groups. In all isolates studied, the bud size and shape were demonstrated to be highly dependent on the mother cell. Importantly, we found strong correlations between PbCDC42 expression and both the shape of mother and bud cells and the size of the buds in all isolates and the knock-down strain. Our results suggested that PbCDC42 expression can explain approximately 80% of mother and bud cell shape and 19% of bud cell size. This data support PbCDC42 expression level as being a relevant predictor of P. brasiliensis morphology. Altogether, these findings quantitatively describe the polymorphic nature of the P. brasiliensis yeast form and provide additional support for the key role of PbCDC42 expression on yeast cell morphology. PMID:22493946

Menino, João F; Osório, Nuno S; Sturme, Mark H J; Barros, Diana; Gomes-Alves, Ana G; Almeida, Agostinho J; Ludovico, Paula; Costa, Patricio; Goldman, Gustavo H; Rodrigues, Fernando

2012-10-01

11

A secreted serine protease of Paracoccidioides brasiliensis and its interactions with fungal proteins  

PubMed Central

Background Paracoccidioides brasiliensis is a thermodimorphic fungus, the causative agent of paracoccidioidomycosis (PCM). Serine proteases are widely distributed and this class of peptidase has been related to pathogenesis and nitrogen starvation in pathogenic fungi. Results A cDNA (Pbsp) encoding a secreted serine protease (PbSP), was isolated from a cDNA library constructed with RNAs of fungal yeast cells recovered from liver of infected mice. Recombinant PbSP was produced in Escherichia coli, and used to develop polyclonal antibodies that were able to detect a 66 kDa protein in the P. brasiliensis proteome. In vitro deglycosylation assays with endoglycosidase H demonstrated that PbSP is a N-glycosylated molecule. The Pbsp transcript and the protein were induced during nitrogen starvation. The Pbsp transcript was also induced in yeast cells infecting murine macrophages. Interactions of PbSP with P. brasiliensis proteins were evaluated by two-hybrid assay in the yeast Saccharomyces cerevisiae. PbSP interacts with a peptidyl prolyl cis-trans isomerase, calnexin, HSP70 and a cell wall protein PWP2. Conclusions A secreted subtilisin induced during nitrogen starvation was characterized indicating the possible role of this protein in the nitrogen acquisition. PbSP interactions with other P. brasiliensis proteins were reported. Proteins interacting with PbSP are related to folding process, protein trafficking and cytoskeleton reorganization. PMID:21080956

2010-01-01

12

Exploring Potential Virulence Regulators in Paracoccidioides brasiliensis Isolates of Varying Virulence through Quantitative Proteomics.  

PubMed

Few virulence factors have been identified for Paracoccidioides brasiliensis, the agent of paracoccidioidomycosis. In this study, we quantitatively evaluated the protein composition of P. brasiliensis in the yeast phase using minimal and rich media to obtain a better understanding of its virulence and to gain new insights into pathogen adaptation strategies. This analysis was performed on two isolates of the Pb18 strain showing distinct infection profiles in B10.A mice. Using liquid chromatography/tandem mass spectrometry (LC-MS/MS) analysis, we identified and quantified 316 proteins in minimal medium, 29 of which were overexpressed in virulent Pb18. In rich medium, 29 out of 295 proteins were overexpressed in the virulent fungus. Three proteins were found to be up-regulated in both media, suggesting the potential roles of these proteins in virulence regulation in P. brasiliensis. Moreover, genes up-regulated in virulent Pb18 showed an increase in its expression after the recovery of virulence of attenuated Pb18. Proteins up-regulated in both isolates were grouped according to their functional categories. Virulent Pb18 undergoes metabolic reorganization and increased expression of proteins involved in fermentative respiration. This approach allowed us to identify potential virulence regulators and provided a foundation for achieving a molecular understanding of how Paracoccidioides modulates the host-pathogen interaction to its advantage. PMID:25145636

Castilho, Daniele G; Chaves, Alison F A; Xander, Patricia; Zelanis, André; Kitano, Eduardo S; Serrano, Solange M T; Tashima, Alexandre K; Batista, Wagner L

2014-10-01

13

Proteomic Analysis Reveals That Iron Availability Alters the Metabolic Status of the Pathogenic Fungus Paracoccidioides brasiliensis  

PubMed Central

Paracoccidioides brasiliensis is a thermodimorphic fungus and the causative agent of paracoccidioidomycosis (PCM). The ability of P. brasiliensis to uptake nutrients is fundamental for growth, but a reduction in the availability of iron and other nutrients is a host defense mechanism many pathogenic fungi must overcome. Thus, fungal mechanisms that scavenge iron from host may contribute to P. brasiliensis virulence. In order to better understand how P. brasiliensis adapts to iron starvation in the host we compared the two-dimensional (2D) gel protein profile of yeast cells during iron starvation to that of iron rich condition. Protein spots were selected for comparative analysis based on the protein staining intensity as determined by image analysis. A total of 1752 protein spots were selected for comparison, and a total of 274 out of the 1752 protein spots were determined to have changed significantly in abundance due to iron depletion. Ninety six of the 274 proteins were grouped into the following functional categories; energy, metabolism, cell rescue, virulence, cell cycle, protein synthesis, protein fate, transcription, cellular communication, and cell fate. A correlation between protein and transcript levels was also discovered using quantitative RT-PCR analysis from RNA obtained from P. brasiliensis under iron restricting conditions and from yeast cells isolated from infected mouse spleens. In addition, western blot analysis and enzyme activity assays validated the differential regulation of proteins identified by 2-D gel analysis. We observed an increase in glycolytic pathway protein regulation while tricarboxylic acid cycle, glyoxylate and methylcitrate cycles, and electron transport chain proteins decreased in abundance under iron limiting conditions. These data suggest a remodeling of P. brasiliensis metabolism by prioritizing iron independent pathways. PMID:21829521

Parente, Ana F. A.; Bailao, Alexandre M.; Borges, Clayton L.; Parente, Juliana A.; Magalhaes, Adriana D.; Ricart, Carlos A. O.; Soares, Celia M. A.

2011-01-01

14

Cryptic species of Paracoccidioides brasiliensis: impact on paracoccidioidomycosis immunodiagnosis.  

PubMed

We aimed to evaluate whether the occurrence of cryptic species of Paracoccidioides brasiliensis, S1, PS2, PS3 and Paracoccidioides lutzii, has implications in the immunodiagnosis of paracoccidioidomycosis (PCM). Small quantities of the antigen gp43 were found in culture filtrates of P. lutzii strains and this molecule appeared to be more variable within P. lutzii because the synonymous-nonsynonymous mutation rate was lower, indicating an evolutionary process different from that of the remaining genotypes. The production of gp43 also varied between isolates belonging to the same species, indicating that speciation events are important, but not sufficient to fully explain the diversity in the production of this antigen. The culture filtrate antigen AgEpm83, which was obtained from a PS3 isolate, showed large quantities of gp43 and reactivity by immunodiffusion assays, similar to the standard antigen (AgB-339) from an S1 isolate. Furthermore, AgEpm83 was capable of serologically differentiating five serum samples from patients from the Botucatu and Jundiaí regions. These patients had confirmed PCM but, were non-reactive to the standard antigen, thus demonstrating an alternative for serological diagnosis in regions in which S1 and PS2 occur. We also emphasise that it is not advisable to use a single antigen preparation to diagnose PCM, a disease that is caused by highly diverse pathogens. PMID:23903981

Machado, Gabriel Capella; Moris, Daniela Vanessa; Arantes, Thales Domingos; Silva, Luciane Regina Franciscone; Theodoro, Raquel Cordeiro; Mendes, Rinaldo Pôncio; Vicentini, Adriana Pardini; Bagagli, Eduardo

2013-08-01

15

Detection of Melanin-Like Pigments in the Dimorphic Fungal Pathogen Paracoccidioides brasiliensis In Vitro and during Infection  

PubMed Central

Melanins are implicated in the pathogenesis of several human diseases, including some microbial infections. In this study, we analyzed whether the conidia and the yeasts of the thermally dimorphic fungal pathogen Paracoccidioides brasiliensis produce melanin or melanin-like compounds in vitro and during infection. Growth of P. brasiliensis mycelia on water agar alone produced pigmented conidia, and growth of yeasts in minimal medium with l-3,4-dihydroxyphenylalanine (l-DOPA) produced pigmented cells. Digestion of the pigmented conidia and yeasts with proteolytic enzymes, denaturant, and hot concentrated acid yielded dark particles that were the same size and shape as their propagules. Immunofluorescence analysis demonstrated reactivity of a melanin-binding monoclonal antibody (MAb) with the pigmented conidia, yeasts, and particles. Electron spin resonance spectroscopy identified the yeast-derived particles produced in vitro when P. brasiliensis was grown in l-DOPA medium as a melanin-like compound. Nonreducing polyacrylamide gel electrophoresis of cytoplasmic yeast extract revealed a protein that catalyzed melanin synthesis from l-DOPA. The melanin binding MAb reacted with yeast cells in tissue from mice infected with P. brasiliensis. Finally digestion of infected tissue liberated particles reactive to the melanin binding MAb that had the typical morphology of P. brasiliensis yeasts. These data strongly suggest that P. brasiliensis propagules, both conidia and yeast cells, can produce melanin or melanin-like compounds in vitro and in vivo. Based on what is known about the function of melanin in the virulence of other fungi, this pigment may play a role in the pathogenesis of paracoccidioidomycosis. PMID:11500453

Gomez, Beatriz L.; Nosanchuk, Joshua D.; Diez, Soraya; Youngchim, Sirida; Aisen, Philip; Cano, Luz E.; Restrepo, Angela; Casadevall, Arturo; Hamilton, Andrew J.

2001-01-01

16

DOSE RESPONSE EFFECT OF Paracoccidioides brasiliensis IN AN EXPERIMENTAL MODEL OF ARTHRITIS  

PubMed Central

Paracoccidioidomycosis (PCM) is caused by the dimorphic fungus Paracoccidioides brasiliensis (Pb) and corresponds to prevalent systemic mycosis in Latin America. The aim of the present work was to evaluate the dose response effect of the fungal yeast phase for the standardization of an experimental model of septic arthritis. The experiments were performed with groups of 14 rats that received doses of 103, 104 or 105 P. brasiliensis (Pb18) cells. The fungi were injected in 50 µL of phosphate-buffered saline (PBS) directly into the knee joints of the animals. The following parameters were analyzed in this work: the formation of swelling in knees infused with yeast cells and the radiological and anatomopathological alterations, besides antibody titer by ELISA. After 15 days of infection, signs of inflammation were evident. At 45 days, some features of damage and necrosis were observed in the articular cartilage. The systemic dissemination of the fungus was observed in 11% of the inoculated animals, and it was concluded that the experimental model is able to mimic articular PCM in humans and that the dose of 105 yeast cells can be used as standard in this model. PMID:24879005

Loth, Eduardo Alexandre; Biazim, Samia Khalil; dos Santos, Jose Henrique Fermino Ferreira; Puccia, Rosana; Brancalhao, Rosimeire Costa; Chasco, Lucineia de Fatima; Gandra, Rinaldo Ferreira; Simao, Rita de Cassia Garcia; de Franco, Marcello Fabiano

2014-01-01

17

Identification of human plasma proteins associated to the cell wall of the pathogenic fungus Paracoccidioides brasiliensis  

PubMed Central

Paracoccidioides brasiliensis and P. lutzii are thermodimorphic species that cause paracoccidioidomycosis. The cell wall is the outermost fungal organelle to form an interface with the host. A number of host effector compounds, including immunologically active molecules, circulate in the plasma. In the present work we extracted cell wall-associated proteins from the yeast pathogenic phase of P. brasiliensis, isolate Pb3, grown in the presence of human plasma, and analyzed bound plasma proteins by liquid chromatography-tandem mass spectrometry. Transport, complement activation/regulation and coagulation pathway were the most abundant functional groups identified. Proteins related to iron/copper acquisition, immunoglobulins, and protease inhibitors were also detected. Several human plasma proteins described here have not been previously reported as interacting with fungal components, specifically, clusterin, hemopexin, transthyretin, ceruloplasmin, alpha-1-antitrypsin, apolipoprotein A-I, and apolipoprotein B-100. Additionally, we observed increased phagocytosis by J774.16 macrophages of Pb3 grown in plasma, suggesting that plasma proteins interacting with P. brasiliensis cell wall might be interfering in the fungal relationship with the host. PMID:23398536

Longo, LVG; Nakayasu, ES; Matsuo, AL; Peres da Silva, R; Sobreira, TJP; Vallejo, MC; Ganiko, L; Almeida, IC; Puccia, R

2013-01-01

18

Oenothein B inhibits the expression of PbFKS1 transcript and induces morphological changes in Paracoccidioides brasiliensis.  

PubMed

The fungus Paracoccidioides brasiliensis is the causative agent of paracoccidioidomycosis (PCM), the most prevalent human systemic mycosis in Latin America. Drug toxicity and the appearance of resistant strains have created the need to search for new therapeutic approaches. Plants with reputed antimicrobial properties represent a rich screening source of potential antifungal compounds. In this work, the growth of P. brasiliensis yeast cells was evaluated in the presence of oenothein B extracted from Eugenia uniflora. The oenothein B dosage that most effectively inhibited the development (74%) of P. brasiliensis yeast cells in vitro was 500 microg/ml. To verify if oenothein B interferes with cell morphology, we observed oenothein B-treated yeast cells by electron microscopy. The micrographs showed characteristic cell changes noted with glucan synthesis inhibition, including squashing, rough surface, cell wall rupture and cell membrane recess. The expression of P. brasiliensis genes was evaluated in order to investigate the action of oenothein B. Here we report that oenothein B inhibits 1,3-beta-glucan synthase (PbFKS1) transcript accumulation. The results indicate that oenothein B interferes with the cell morphology of P. brasiliensis, probably by inhibiting the transcription of 1,3-beta-glucan synthase gene, which is involved in the cell wall synthesis. PMID:18033615

Santos, Glaciane D; Ferri, Pedro H; Santos, Suzana C; Bao, Sônia N; Soares, Célia M A; Pereira, Maristela

2007-11-01

19

Cloning and characterization of a LON gene homologue from the human pathogen Paracoccidioides brasiliensis.  

PubMed

A LON gene homologue from the human pathogen Paracoccidioides brasiliensis (PbLON) has been cloned, sequenced and characterized. It encodes a putative ATP-dependent proteinase Lon, which in Saccharomyces cerevisisae (PIM1) is a heat-inducible protein involved in the degradation of abnormal or short-lived proteins in the mitochondria. The PbLON ORF is within a 3369 bp fragment interrupted by two introns located in the 3'segment. The 5' and 3' regions flanking the ORF contain sequences which resemble known transcription elements. Several transcription binding factor motifs have also been found, including sites for heat shock/stress response and nitrogen control. The deduced protein consists of 1063 residues containing a mitochondrial import signal at the N-terminus and conserved ATP-binding (GPPGVGKT) and serine catalytic (KDGPSAG) sites. It shares high identity with Lon homologues from S. cerevisiae (73%), Homo sapiens (62%) and Escherichia coli (56%). In P. brasiliensis, an MDJ1 putative gene has also been partially sequenced adjacent to PbLON, possibly sharing divergently orientated promoter elements. This chromosomal organization is interesting, since Mdj1p is a heat shock chaperone essential for substrate degradation by PIM1 in yeast. PMID:11447604

Barros, T F; Puccia, R

2001-07-01

20

Cryptic Speciation and Recombination in the Fungus Paracoccidioides brasiliensis as Revealed by Gene Genealogies  

Microsoft Academic Search

Paracoccidioides brasiliensis is the etiologic agent of paracoccidioidomycosis, a disease confined to Latin America and of marked importance in the endemic areas due to its frequency and severity. This species is considered to be clonal according to mycological criteria and has been shown to vary in virulence. To characterize natural genetic variation and reproductive mode in this fungus, we analyzed

Daniel R. Matute; Juan G. McEwen; Rosana Puccia; Beatriz A. Montes; Gioconda San-Blas; Eduardo Bagagli; Jason T. Rauscher; Angela Restrepo; Favia Morais; Gustavo Nino-Vega; John W. Taylor

2005-01-01

21

Purification of Paracoccidioides brasiliensis catalase P: subsequent kinetic and stability studies.  

PubMed

Catalases are essential components of the cellular equipment to cope with oxidative stress. Here we have purified a highly abundant catalase P of Paracoccidioides brasiliensis (PbCatP) that is preferentially expressed in the parasitic yeast phase. This oxidative stress-induced protein was isolated from yeast cells grown in the presence of 15 mM of hydrogen peroxide (H(2)O(2)). We have used consecutive steps of protein precipitation and gel filtration chromatography to achieve the purified protein. Protein purification was validated using matrix-assisted laser desorption ionization time-of-flight mass spectrometry and bioinformatics analysis. The purified enzyme showed strong similarity to small-subunit catalases. Like most monofunctional catalases, PbCatP is a homotetramer, resistant to inactivation by acidic conditions, temperature and denaturants. Furthermore, the kinetic behaviour of catalase P was observed to be different at low compared to high H(2)O(2) concentrations. The results demonstrated that a purified PbCatP is a homotetrameric enzyme, classified as a small subunit catalase. PMID:19897569

Chagas, Ronney Fernandes; Bailão, Alexandre Melo; Fernandes, Kátia Flávia; Winters, Michael S; Pereira, Maristela; Soares, Célia Maria de Almeida

2010-03-01

22

Vesicle and Vesicle-Free Extracellular Proteome of Paracoccidioides brasiliensis: Comparative Analysis with other Pathogenic Fungi  

PubMed Central

Microorganisms release effector molecules that modulate the host machinery enabling survival, replication, and dissemination of a pathogen. Here we characterized the extracellular proteome of Paracoccidioides brasiliensis at its pathogenic yeast phase. Cell-free culture supernatants from the Pb18 isolate, cultivated in defined medium, were separated into vesicle and vesicle-free fractions, digested with trypsin and analyzed by liquid chromatography-tandem mass spectrometry. In vesicle and vesicle-free preparations we identified, respectively, 205 and 260 proteins with two or more peptides, including 120 overlapping identifications. Almost 70% of the sequences were predicted as secretory, mostly using non-conventional secretory pathways, and many have previously been localized to fungal cell walls. A total of 72 proteins were considered as commonly transported by extracellular vesicles, considering that orthologues have been reported in at least two other fungal species. These sequences were mostly related to translation, carbohydrate and protein metabolism, oxidation/reduction, transport, response to stress, and signaling. This unique proteomic analysis of extracellular vesicles and vesicle-free released proteins in a pathogenic fungus provides full comparison with other fungal extracellular vesicle proteomes and broadens the current view on fungal secretomes. PMID:22288420

Vallejo, Milene C.; Nakayasu, Ernesto S.; Matsuo, Alisson L.; Sobreira, Tiago J. P.; Longo, Larissa V. G.; Ganiko, Luciane; Almeida, Igor C.; Puccia, Rosana

2012-01-01

23

Characterization of PbPga1, an Antigenic GPI-Protein in the Pathogenic Fungus Paracoccidioides brasiliensis  

PubMed Central

Paracoccidioides brasiliensis is the etiologic agent of paracoccidioidomycosis (PCM), one of the most prevalent mycosis in Latin America. P. brasiliensis cell wall components interact with host cells and influence the pathogenesis of PCM. Cell wall components, such as glycosylphosphatidylinositol (GPI)-proteins play a critical role in cell adhesion and host tissue invasion. Although the importance of GPI-proteins in the pathogenesis of other medically important fungi is recognized, little is known about their function in P. brasiliensis cells and PCM pathogenesis. We cloned the PbPga1 gene that codifies for a predicted GPI-anchored glycoprotein from the dimorphic pathogenic fungus P. brasiliensis. PbPga1 is conserved in Eurotiomycetes fungi and encodes for a protein with potential glycosylation sites in a serine/threonine-rich region, a signal peptide and a putative glycosylphosphatidylinositol attachment signal sequence. Specific chicken anti-rPbPga1 antibody localized PbPga1 on the yeast cell surface at the septum between the mother cell and the bud with stronger staining of the bud. The exposure of murine peritoneal macrophages to rPbPga1 induces TNF-? release and nitric oxide (NO) production by macrophages. Furthermore, the presence of O-glycosylation sites was demonstrated by ?-elimination under ammonium hydroxide treatment of rPbPga1. Finally, sera from PCM patients recognized rPbPga1 by Western blotting indicating the presence of specific antibodies against rPbPga1. In conclusion, our findings suggest that the PbPga1gene codifies for a cell surface glycoprotein, probably attached to a GPI-anchor, which may play a role in P. brasiliensis cell wall morphogenesis and infection. The induction of inflammatory mediators released by rPbPga1 and the reactivity of PCM patient sera toward rPbPga1 imply that the protein favors the innate mechanisms of defense and induces humoral immunity during P. brasiliensis infection. PMID:23024763

Valim, Clarissa X. R.; Basso, Luiz Roberto; dos Reis Almeida, Fausto B.; Reis, Thaila Fernanda; Damasio, Andre Ricardo Lima; Arruda, Luisa Karla; Martinez, Roberto; Roque-Barreira, Maria Cristina; Oliver, Constance; Jamur, Maria Celia; Coelho, Paulo Sergio Rodrigues

2012-01-01

24

New Developments of RNAi in Paracoccidioides brasiliensis: Prospects for High-Throughput, Genome-Wide, Functional Genomics  

PubMed Central

Background The Fungal Genome Initiative of the Broad Institute, in partnership with the Paracoccidioides research community, has recently sequenced the genome of representative isolates of this human-pathogen dimorphic fungus: Pb18 (S1), Pb03 (PS2) and Pb01. The accomplishment of future high-throughput, genome-wide, functional genomics will rely upon appropriate molecular tools and straightforward techniques to streamline the generation of stable loss-of-function phenotypes. In the past decades, RNAi has emerged as the most robust genetic technique to modulate or to suppress gene expression in diverse eukaryotes, including fungi. These molecular tools and techniques, adapted for RNAi, were up until now unavailable for P. brasiliensis. Methodology/Principal Findings In this paper, we report Agrobacterium tumefaciens mediated transformation of yeast cells for high-throughput applications with which higher transformation frequencies of 150±24 yeast cell transformants per 1×106 viable yeast cells were obtained. Our approach is based on a bifunctional selective marker fusion protein consisted of the Streptoalloteichus hindustanus bleomycin-resistance gene (Shble) and the intrinsically fluorescent monomeric protein mCherry which was codon-optimized for heterologous expression in P. brasiliensis. We also report successful GP43 gene knock-down through the expression of intron-containing hairpin RNA (ihpRNA) from a Gateway-adapted cassette (cALf) which was purpose-built for gene silencing in a high-throughput manner. Gp43 transcript levels were reduced by 73.1±22.9% with this approach. Conclusions/Significance We have a firm conviction that the genetic transformation technique and the molecular tools herein described will have a relevant contribution in future Paracoccidioides spp. functional genomics research. PMID:25275433

Goes, Tercio; Bailao, Elisa Flavia L. C.; Correa, Cristiane R.; Bozzi, Adriana; Santos, Luara I.; Gomes, Dawidson A.; Soares, Celia M. A.; Goes, Alfredo M.

2014-01-01

25

Characterization of Paracoccidioides brasiliensis isolates by random amplified polymorphic DNA analysis.  

PubMed Central

We initially used 25 different random primers in order to test their ability to generate random amplified polymorphic DNA fragments from the dimorphic human pathogenic fungus Paracoccidioides brasiliensis. From the tested primers we chose five to distinguish between seven isolates of this microorganism. The DNA amplification patterns allowed clear differentiation of the seven isolates into two distinct groups with only 35% genomic identity. One of these groups contained two subgroups with 81% genetic similarity. The random amplified polymorphic DNA analysis method proved to be a good tool for analyzing and comparing different genomes of P. brasiliensis isolates. PMID:7714219

Soares, C M; Madlun, E E; da Silva, S P; Pereira, M; Felipe, M S

1995-01-01

26

On the unknown ecological niche of Paracoccidioides brasiliensis: our hypothesis of 1989: present status and perspectives.  

PubMed

In 1989, CONTI DIAZ & RILLA published a hypothesis concerning the as yet unknown ecological niche of Paracoccidioides brasiliensis. The hypothesis proposed a highly efficient paracoccidioidal ecological strategy based on an important natural reservoir of the parasite, probably in heterothermic animals from fresh water environments. Further, the hypothesis proposed, a transient and variable residence in the soil with a wide aleuriospore dispersion throughout the environment together with an elevated capability of infecting humans, and domestic and wild animals. This paper analyzes scientific publications from the IX International Meeting on Paracoccidioidomycosis held in Aguas de Lindoia, São Paulo, Brazil from 2-5 October 2005, providing a comparative study among this articles and with other recently published papers and the hypothesis' postulates. Since various findings and observations appear to agree with the postulates, the pursuit of novel, specific research projects in the supposed reservoirs is recommended partially or fully to confirm the hypothesis using classical laboratorial methods and modern molecular biology techniques. PMID:17505676

Conti Días, Ismael A

2007-01-01

27

Induction of antigen-specific T suppressor cells by soluble Paracoccidioides brasiliensis antigen.  

PubMed Central

In naturally acquired paracoccidioidomycosis, patients have depressed in vivo and in vitro cell-mediated immune (CMI) responses to Paracoccidioides brasiliensis antigen. In addition, it has been reported that these patients have significant levels of circulating paracoccidioidal antigen in their sera. The primary purpose of this investigation was to assess the effects of P. brasiliensis antigen on the CMI responses in a mouse model. On the basis of findings with other fungal agents, we predicted that circulating paracoccidioidal antigen may be inducing suppressor cells which modulate the CMI response. In this study, we show (i) that a soluble P. brasiliensis culture filtrate antigen (Pb.Ag) emulsified in complete Freund adjuvant and injected subcutaneously into mice induces reasonably high levels of delayed-type hypersensitivity (DTH) in CBA/J mice; (ii) that Pb.Ag elicits DTH reactions specific for P. brasiliensis when injected into footpads of immunized mice; and (iii) that an intravenous injection of Pb.Ag induces a population of lymph node and spleen cells which, upon adoptive transfer, suppress the afferent limb of the DTH response to paracoccidioidal antigen. The afferent suppressor cells can be detected in spleens as early as 5 days after Pb.Ag treatment, are present in significant numbers by 7 days in both spleens and lymph nodes, and are virtually absent by 14 days. In contrast, at 14 days after antigen injection, efferent suppressor cells were detected in spleens and lymph nodes. The Pb.Ag-induced afferent suppressor cells specifically inhibit the antiparacoccidioidal DTH response. They are nylon wool-nonadherent cells, and their activity is abrogated by anti-Thy-1 and complement treatment, indicating that they are T lymphocytes. The phenotype of these afferent suppressor T cells is L3T4+ Lyt-1+2- I-J+. The Pb.Ag-specific suppressor cells described in this paper are similar to the Ts1 cells in the azobenzenearsonate, 4-hydroxy-3-nitrophenyl acetyl, and cryptococcal models of suppression of the DTH response and to the afferent suppressor cells in the dinitrofluorobenzene contact sensitivity system. Images PMID:2964411

Jimenez-Finkel, B E; Murphy, J W

1988-01-01

28

Paracoccidioides brasiliensis and P. lutzii antigens elicit different serum IgG responses in chronic paracoccidioidomycosis.  

PubMed

Paracoccidioidomycosis (PCM) is a systemic mycosis caused by the fungus Paracoccidioides brasiliensis (S1, PS2, and PS3) and by the new species, P. lutzii. Considering that genetic differences in the Paracoccidioides genus could elicit distinct immune responses by the host, current research investigated serum IgG levels to antigens from P. brasiliensis B339 (S1), P. brasiliensis LDR3 (PS2), and atypical strain LDR2 (P. lutzii), in patients with chronic PCM from the northern and west regions of Paraná, Brazil (n = 35). Cell-free antigen (CFA) and high molecular mass fraction (hMM) were produced from each strain. Samples were analyzed by ELISA and immunodiffusion (ID). ELISA positivity using CFA: B339-100 %, LDR3-83 %, and LDR2-74 %. Response to CFA from B339 was more intense (p < 0.05), while there was no difference between LDR3-LDR2. IgG anti-hMM was higher for antigens from B339 or LDR3, when compared with LDR2 (p < 0.05). There was a positive correlation for each strain between CFA-hMM and for hMM between B339-LDR3 and LDR3-LDR2. ID positivity with CFA: B339-63 %, LDR3-66 %, and LDR2-60 %. We conclude that the intensity of reaction of the patients' sera varies with the strain used; hMM influences tests that use CFA, independently of strain; using ID, positive rates were very similar, but there was a large number of false negative results; ELISA tests using antigens from P. brasiliensis S1 were able to detect a larger number of patients than PS2 and P. lutzii (which had a considerable number of false negative results), and therefore, its use may be more appropriate in this region of Brazil. PMID:24005606

Lenhard-Vidal, A; Assolini, J P; Ono, M A; Bredt, C S O; Sano, A; Itano, E N

2013-12-01

29

Activation of the alternative complement pathway in canine normal serum by Paracoccidioides brasiliensis  

PubMed Central

The dimorphic fungus Paracoccidioides brasiliensis is the etiological agent of paracoccidioidomycosis, a human granulomatous disease. Recently the first case of natural disease in dogs was reported. The complement system is an important effector component of humoral immunity against infectious agents. Therefore, the aim of this study was to evaluate the activation of the dog alternative complement pathway by P. brasiliensis. Initially, the ability of erythrocytes of guinea pig, rabbit, sheep, chicken and swine to activate the dog alternative pathway was evaluated. The guinea pig erythrocytes showed the greatest capacity to activate dog alternative pathway. The alternative (AH50) hemolytic activity was evaluated in 27 serum samples from healthy dogs and the mean values were 87.2 AH50/ml. No significant differences were observed in relation to sex and age. The alternative pathway activation by P. brasiliensis was higher in serum samples from adult dogs when compared to puppies and aged dogs (p ? 0.05). This is the first report of dog alternative complement pathway activation by P. brasiliensis and suggests that it may play a protective role in canine paracoccidioidomycosis. PMID:24031350

Bianchini, A.A.C.; Petroni, T.F.; Fedatto, P.F.; Bianchini, R.R.; Venancio, E.J.; Itano, E.N.; Ono, M.A.

2009-01-01

30

Correlation between Histopathological and FT-Raman Spectroscopy Analysis of the Liver of Swiss Mice Infected with Paracoccidioides brasiliensis  

PubMed Central

Paracoccidioidomycosis is the most important systemic mycosis in Latin America. The main entrance of the fungus is the airway. It primarily occurs in the lung, but in its disseminated form may affect any organ. The liver is one of the organs afflicted by this disease and its homeostasis may be impaired. The aim of the present study was to evaluate the evolution of paracoccidioidomycosis in the liver of Swiss mice and correlate morphological factors with the expression of gp43 and with physicochemical analysis via FT-Raman of the infected organ. According to colony forming unit (CFU) and granuloma counting, the first and second weeks were the periods when infection was most severe. Tissue response was characterized by the development of organized granulomas and widespread infection, with yeasts located within the macrophages and isolated hepatocytes. The gp43 molecule was distributed throughout the hepatic parenchyma, and immunostaining was constant in all observed periods. The main physicochemical changes of the infected liver were observed in the spectral ranges between 1700–1530 cm?1 and 1370 – 1290 cm?1, a peak shifting center attributed to phenylalanine and area variation of -CH2 and -CH3 compounds associated to collagen, respectively. Over time, there was a direct proportional relationship between the number of CFUs, the number of granulomas and the physicochemical changes in the liver of mice infected with Paracoccidioides brasiliensis. The expression of gp43 was similar in all observed periods. PMID:25181524

Mansano, Elaine Sciuniti Benites; de Morais, Gutierrez Rodrigues; Moratto, Edilaine Martins; Sato, Francielle; Medina Neto, Antonio; Svidzinski, Terezinha Ines Estivalet; Baesso, Mauro Luciano; Hernandes, Luzmarina

2014-01-01

31

Recombinant Paracoccin Reproduces the Biological Properties of the Native Protein and Induces Protective Th1 Immunity against Paracoccidioides brasiliensis Infection  

PubMed Central

Background Paracoccin is a dual-function protein of the yeast Paracoccidioides brasiliensis that has lectin properties and N-acetylglucosaminidase activities. Proteomic analysis of a paracoccin preparation from P. brasiliensis revealed that the sequence matched that of the hypothetical protein encoded by PADG-3347 of isolate Pb-18, with a polypeptide sequence similar to the family 18 endochitinases. These endochitinases are multi-functional proteins, with distinct lectin and enzymatic domains. Methodology/principal findings The multi-exon assembly and the largest exon of the predicted ORF (PADG-3347), was cloned and expressed in Escherichia coli cells, and the features of the recombinant proteins were compared to those of the native paracoccin. The multi-exon protein was also used for protection assays in a mouse model of paracoccidioidomycosis. Conclusions/Significance Our results showed that the recombinant protein reproduced the biological properties described for the native protein—including binding to laminin in a manner that is dependent on carbohydrate recognition—showed N-acetylglucosaminidase activity, and stimulated murine peritoneal macrophages to produce high levels of TNF-? and nitric oxide. Considering the immunomodulatory potential of glycan-binding proteins, we also investigated whether prophylactic administration of recombinant paracoccin affected the course of experimental paracoccidioidomycosis in mice. In comparison to animals injected with vehicle (controls), mice treated with recombinant paracoccin displayed lower pulmonary fungal burdens and reduced pulmonary granulomas. These protective effects were associated with augmented pulmonary levels of IL-12 and IFN-?. We also observed that injection of paracoccin three days before challenge was the most efficient administration protocol, as the induced Th1 immunity was balanced by high levels of pulmonary IL-10, which may prevent the tissue damage caused by exacerbated inflammation. The results indicated that paracoccin is the protein encoded by PADG-3347, and we propose that this gene and homologous proteins in other P. brasiliensis strains be called paracoccin. We also concluded that recombinant paracoccin confers resistance to murine P. brasiliensis infection by exerting immunomodulatory effects. PMID:24743161

Alegre, Ana Claudia Paiva; Oliveira, Aline Ferreira; Dos Reis Almeida, Fausto Bruno; Roque-Barreira, Maria Cristina; Hanna, Ebert Seixas

2014-01-01

32

Isolation and antigenicity of a 45-kilodalton Paracoccidioides brasiliensis immunodominant antigen.  

PubMed Central

In the present study, we analyzed human antibody responses to Paracoccidioides brasiliensis cellular antigens by the immunoblot technique to identify specific cellular components and to investigate the existence of antigen profile differences among serological responses of paracoccidioidomycosis (PCM) patients. Among the 64 PCM serum samples analyzed, a relatively homogeneous immunoglobulin G response to P. brasiliensis antigens was observed. The polypeptide with a mass of 45 kDa was the most clinically important, since antibody to this antigen was detectable in 90.6% of PCM patients studied and the six individuals who did not produce antibody were either at the end of treatment or in the posttherapy period and had shown clinical recovery. These facts suggested that the presence of this antibody may be an indicator of active disease. The 45-kDa antigen was also the most specific antigen of the PCM humoral immune response, since it reacted with only 2 of 79 (2.5%) heterologous serum samples tested: 1 histoplasmosis case and 1 tuberculosis case. This polypeptide was isolated from gels by electroelution and, when tested by an immunoradiometric assay and immunoblotting, maintained its reactivity with PCM sera and also with anti-P. brasiliensis polyclonal antibodies raised in rabbits at the same sensitivity levels as those obtained in immunoblotting with a crude antigen. Since in our assays the 45-kDa polypeptide was the major P. brasiliensis antigen and seemed to be specific for PCM, its use in alternative diagnostic methods is promising, especially in patients suspected of having the juvenile clinical form of PCM often associated with negative double-immunodiffusion results. Images PMID:1612736

Ferreira-da-Cruz, M F; Galvao-Castro, B; Daniel-Ribeiro, C

1992-01-01

33

Immunological Basis for the Gender Differences in Murine Paracoccidioides brasiliensis Infection  

PubMed Central

This study aimed to investigate the immunological mechanisms involved in the gender distinct incidence of paracoccidioidomycosis (pcm), an endemic systemic mycosis in Latin America, which is at least 10 times more frequent in men than in women. Then, we compared the immune response of male and female mice to Paracoccidioides brasiliensis infection, as well as the influence in the gender differences exerted by paracoccin, a P. brasiliensis component with carbohydrate recognition property. High production of Th1 cytokines and T-bet expression have been detected in the paracoccin stimulated cultures of spleen cells from infected female mice. In contrast, in similar experimental conditions, cells from infected males produced higher levels of the Th2 cytokines and expressed GATA-3. Macrophages from male and female mice when stimulated with paracoccin displayed similar phagocytic capability, while fungicidal activity was two times more efficiently performed by macrophages from female mice, a fact that was associated with 50% higher levels of nitric oxide production. In order to evaluate the role of sexual hormones in the observed gender distinction, we have utilized mice that have been submitted to gonadectomy followed by inverse hormonal reconstitution. Spleen cells derived from castrated males reconstituted with estradiol have produced higher levels of IFN-? (1291±15 pg/mL) and lower levels of IL-10 (494±38 pg/mL), than normal male in response to paracoccin stimulus. In contrast, spleen cells from castrated female mice that had been treated with testosterone produced more IL-10 (1284±36 pg/mL) and less IFN-? (587±14 pg/mL) than cells from normal female. In conclusion, our results reveal that the sexual hormones had a profound effect on the biology of immune cells, and estradiol favours protective responses to P. brasiliensis infection. In addition, fungal components, such as paracoccin, may provide additional support to the gender dimorphic immunity that marks P. brasiliensis infection. PMID:20505765

Pinzan, Camila Figueiredo; Ruas, Luciana Pereira; Casabona-Fortunato, Analia Sulamita; Carvalho, Fernanda Caroline; Roque-Barreira, Maria-Cristina

2010-01-01

34

High frequency of Paracoccidioides brasiliensis infection in armadillos (Dasypus novemcinctus): an ecological study.  

PubMed

The fungus Paracoccidioides brasiliensis has been isolated from nine-banded armadillos (Dasypus novemcinctus) in different regions where paracoccidiodomycosis (PCM) is endemic. The link between PCM and these animals has provided the first valuable clue in the effort to elucidate the ecological niche of P. brasiliensis. The present study was aimed at correlating P. brasiliensis infection in armadillos with local ecological features and, if possible, the presence of the fungus in the soil in the Botucatu hyperendemic area of PCM. In this region the mean temperature ranges from 14.8 to 25.8 degrees C and the annual average precipitation is 1520 mm. The sites where 10 infected animals (positive group) were collected were studied and compared with the sites where five uninfected animals were found. The occurrence of the fungus in soil samples collected from the positive armadillos' burrows and foraging sites was investigated by the indirect method of animal inoculation. Environmental data from the sites of animal capture, such as temperature, rainfall, altitude, vegetation, soil composition, presence of water and proximity of urban areas, were recorded. All 37 soil samples collected from the sites had negative fungal cultures. Positive animals were found much more frequently in sites with disturbed vegetation, such as riparian forests and artificial Eucalyptus or Pinus forests, in altitudes below 800 m, near water sources. The soil type of the sites of positive animals was mainly sandy, with medium to low concentrations of organic matter. The pH was mainly acidic at all the sites, although the concentrations of aluminum cations (H+Al) were lower at the sites where positive animals were found. Positive armadillos were also captured in sites very close to urban areas. Our data and previous studies indicate that P. brasiliensis occurs preferentially in humid and shady disturbed forests in a strong association with armadillos. PMID:12964713

Bagagli, E; Franco, M; Bosco, S De M G; Hebeler-Barbosa, F; Trinca, L A; Montenegro, M R

2003-06-01

35

Influence of Different Media, Incubation Times, and Temperatures for Determining the MICs of Seven Antifungal Agents against Paracoccidioides brasiliensis by Microdilution  

PubMed Central

MIC assays with Paracoccidioides brasiliensis, the etiological agent of paracoccidioidomycosis, had been conducted with variable protocols, employing both macrodilution and microdilution tests and including differences in inoculum preparation, media used, incubation periods, and temperatures. Twenty-one clinical and environmental isolates of Paracoccidioides were tested using amphotericin B, itraconazole, ketoconazole, fluconazole, sulfamethoxazole, sulfamethoxazole-trimethoprim, and terbinafine, according to the National Committee for Clinical Laboratory Standards (National Committee for Clinical Laboratory Standards, document M27-A2, 2002), with modifications such as three medium formulations (RPMI 1640 medium, McVeigh and Morton [MVM] medium, and modified Mueller-Hinton [MMH] medium), two incubation temperatures (room temperature [25 to 28°C] and 37°C), and three incubation periods (7, 10, and 15 days). The antifungal activities were also classified as fungicidal or fungistatic. The best results were obtained after 15 days of incubation, which was chosen as the standard incubation time. The MICs for most individual isolates grown for the same length of time at the same temperature varied with the different media used (P < 0.05). Of the isolates, 81% showed transition from the yeast to the mycelial form in RPMI 1640 medium at 37°C, independent of the presence of antifungals. MMH medium appears to be a suitable medium for susceptibility testing of antifungal drugs with P. brasiliensis, except for sulfamethoxazole and the combination of sulfamethoxazole-trimethoprim, for which the MVM medium yielded better results. The incubation temperature influenced the MICs, with, in general, higher MICs at 25°C (mycelial form) than at 37°C (P < 0.05). Based on our results, we tentatively propose a microdilution assay protocol for susceptibility testing of antifungal drugs against Paracoccidioides. PMID:23175254

Cruz, R. C.; Werneck, S. M. C.; Oliveira, C. S.; Santos, P. C.; Soares, B. M.; Santos, D. A.

2013-01-01

36

The transcriptome analysis of early morphogenesis in Paracoccidioides brasiliensis mycelium reveals novel and induced genes potentially associated to the dimorphic process  

PubMed Central

Background Paracoccidioides brasiliensis is a human pathogen with a broad distribution in Latin America. The fungus is thermally dimorphic with two distinct forms corresponding to completely different lifestyles. Upon elevation of the temperature to that of the mammalian body, the fungus adopts a yeast-like form that is exclusively associated with its pathogenic lifestyle. We describe expressed sequence tags (ESTs) analysis to assess the expression profile of the mycelium to yeast transition. To identify P. brasiliensis differentially expressed sequences during conversion we performed a large-scale comparative analysis between P. brasiliensis ESTs identified in the transition transcriptome and databases. Results Our analysis was based on 1107 ESTs from a transition cDNA library of P. brasiliensis. A total of 639 consensus sequences were assembled. Genes of primary metabolism, energy, protein synthesis and fate, cellular transport, biogenesis of cellular components were represented in the transition cDNA library. A considerable number of genes (7.51%) had not been previously reported for P. brasiliensis in public databases. Gene expression analysis using in silico EST subtraction revealed that numerous genes were more expressed during the transition phase when compared to the mycelial ESTs [1]. Classes of differentially expressed sequences were selected for further analysis including: genes related to the synthesis/remodeling of the cell wall/membrane. Thirty four genes from this family were induced. Ten genes related to signal transduction were increased. Twelve genes encoding putative virulence factors manifested increased expression. The in silico approach was validated by northern blot and semi-quantitative RT-PCR. Conclusion The developmental program of P. brasiliensis is characterized by significant differential positive modulation of the cell wall/membrane related transcripts, and signal transduction proteins, suggesting the related processes important contributors to dimorphism. Also, putative virulence factors are more expressed in the transition process suggesting adaptation to the host of the yeast incoming parasitic phase. Those genes provide ideal candidates for further studies directed at understanding fungal morphogenesis and its regulation. PMID:17425801

Bastos, Karinne P; Bailao, Alexandre M; Borges, Clayton L; Faria, Fabricia P; Felipe, Maria SS; Silva, Mirelle G; Martins, Wellington S; Fiuza, Rogerio B; Pereira, Maristela; Soares, Celia MA

2007-01-01

37

Antifungal activity of extracts of some plants used in Brazilian traditional medicine against the pathogenic fungus Paracoccidioides brasiliensis.  

PubMed

Paracoccidioidomycosis (PCM) is a systemic granulomatous disease caused by Paracoccidioides brasiliensis Almeida (Onygenales) that requires 1-2 years of treatment. In the absence of drug therapy, the disease is usually fatal, highlighting the need for the identification of safer, novel, and more effective antifungal compounds. With this need in mind, several plants employed in Brazilian traditional medicine were assayed on P. brasiliensis and murine macrophages. Extracts were prepared from 10 plant species: Inga spp. Mill. (Leguminosae), Schinus terebinthifolius Raddi (Anacardiaceae), Punica granatum L. (Punicaceae), Alternanthera brasiliana Kuntze (Amaranthaceae), Piper regnellii CDC. (Piperaceae), P. abutiloides Kunth (Piperaceae), Herissantia crispa L. Briz. (Malvaceae), Rubus urticaefolius Poir (Rosaceae), Rumex acetosa L. (Polygonaceae), and Baccharis dracunculifolia DC. (Asteraceae). Hexane fractions from hydroalcoholic extracts of Piper regnellii and Baccharis dracunculifolia were the most active against the fungus, displaying minimum inhibitory concentration (MIC) values of 7.8 microg/mL and 7.8-30 mug/mL, respectively. Additionally, neither of the extracts exhibited any apparent cytotoxic effects on murine macrophages at 20 microg/mL. Analyses of these fractions using gas chromatography-mass spectrometry (GC-MS) showed that the major components of B. dracunculifolia were ethyl hydrocinnamate (14.35%) and spathulenol (16.02%), while the major components of the hexane fraction of Piper regnellii were 1-methoxy-4-(1-propenyl) benzene (21.94%) and apiol (21.29%). The activities of these fractions against P. brasiliensis without evidence of cytotoxicity to macrophages justify their investigation as a potential source of new chemical agents for the treatment of PCM. PMID:20645716

Johann, Susana; Cisalpino, Patricia Silva; Watanabe, Gisele Almeida; Cota, Betania Barros; de Siqueira, Ezequias Pessoa; Pizzolatti, Moacir Geraldo; Zani, Carlos Leomar; de Resende, Maria Aparecida

2010-04-01

38

Paracoccidioides lutzii Plp43 Is an Active Glucanase with Partial Antigenic Identity with P. brasiliensis gp43  

PubMed Central

Background Paracoccidioides brasiliensis and P. lutzii cause paracoccidioidomycosis (PCM). P. brasiliensis main diagnostic antigen is glycoprotein gp43, and its peptide sequence is 81% identical with a P. lutzii ortholog here called Plp43. P. lutzii (“Pb01-like”) apparently predominates in Midwestern/Northern Brazil, where high percentages of false-negative reactions using P. brasiliensis antigens have recently been reported. The aim of this work was to produce recombinant Plp43 to study its antigenic identity with gp43. Methodology We expressed rPlp43 as a secreted major component in Pichia pastoris and studied its reactivity in immunoblot with PCM patients' sera from Southwestern and Midwestern Brazil. Principal Findings We showed that rPlp43 is not glycosylated and bears glucanase activity. The protein did not react with anti-gp43 monoclonal antibodies in immunoblot, suggesting absence of the corresponding gp43 epitopes. Nevertheless, common epitope(s) might exist, considering that gp43-positive PCM sera recognized rPlp43 in immunoblot, while gp43-negative sera (33 out of 51) from patients resident in Midwestern Brazil were also rPlp43-negative. Two genotyped P. lutzii were from patients with gp43-negative sera, suggesting that non-reactive sera are from patients infected with this species. Conclusion Our data suggest that gp43 and Plp43 bear one or only a few common epitopes and that gp43 cannot be used in diagnosis of PCM patients infected with P. lutzii probably because Plp43 is poorly expressed during infection. PMID:25166744

Leitao, Natanael P.; Vallejo, Milene C.; Conceicao, Palloma M.; Camargo, Zoilo P.; Hahn, Rosane; Puccia, Rosana

2014-01-01

39

New Paracoccidioides brasiliensis isolate reveals unexpected genomic variability in this human pathogen  

E-print Network

Brasi´lia, Brazil c Universidade Federal de Goia´s, Brazil d Corporacio´n para Investigaciones Biolo. brasiliensis isolates, revealed genetic vari- ability and clusters correlated with geography (Calcagno et al

40

Effects of propolis from Brazil and Bulgaria on fungicidal activity of macrophages against Paracoccidioides brasiliensis  

Microsoft Academic Search

Paracoccidioidomycosis is the most important systemic mycosis in Latin America. Its etiological agent, Paracoccidoides brasiliensis, affects individuals living in endemic areas through inhalation of airborne conidia or mycelial fragments. The disease may affect different organs and systems, with multiple clinical features, with cell-mediated immunity playing a significant role in host defence. Peritoneal macrophages from BALB\\/c mice were stimulated with Brazilian

J. M Murad; S. A Calvi; A. M. V. C Soares; V Bankova; J. M Sforcin

2002-01-01

41

Biochemical characterization of Paracoccidioides brasiliensis ?-1,3-glucanase Agn1p, and its functionality by heterologous Expression in Schizosaccharomyces pombe.  

PubMed

?-1,3-Glucan is present as the outermost layer of the cell wall in the pathogenic yeastlike (Y) form of Paracoccidioides brasiliensis. Based on experimental evidence, this polysaccharide has been proposed as a fungal virulence factor. To degrade ?-1,3-glucan and allow remodeling of the cell wall, ?-1,3-glucanase is required. Therefore, the study of this enzyme, its encoding gene, and regulatory mechanisms, might be of interest to understand the morphogenesis and virulence process in this fungus. A single gene, orthologous to other fungal ?-1,3-glucanase genes, was identified in the Paracoccidioides genome, and labeled AGN1. Transcriptional levels of AGN1 and AGS1 (?-1,3-glucan synthase-encoding gene) increased sharply when the pathogenic Y phase was cultured in the presence of 5% horse serum, a reported booster for cell wall ?-1,3-glucan synthesis in this fungus. To study the biochemical properties of P. brasiliensis Agn1p, the enzyme was heterologously overexpressed, purified, and its activity profile determined by means of the degradation of carboxymethyl ?-1,3-glucan (SCMG, chemically modified from P. brasiliensis ?-1,3-glucan), used as a soluble substrate for the enzymatic reaction. Inhibition assays, thin layer chromatography and enzymatic reactions with alternative substrates (dextran, starch, chitin, laminarin and cellulose), showed that Agn1p displays an endolytic cut pattern and high specificity for SCMG. Complementation of a Schizosaccharomyces pombe agn1? strain with the P. brasiliensis AGN1 gene restored the wild type phenotype, indicating functionality of the gene, suggesting a possible role of Agn1p in the remodeling of P. brasiliensis Y phase cell wall. Based on amino acid sequence, P. brasiliensis Agn1p, groups within the family 71 of fungal glycoside hydrolases (GH-71), showing similar biochemical characteristics to other members of this family. Also based on amino acid sequence alignments, we propose a subdivision of fungal GH-71 into at least five groups, for which specific conserved sequences can be identified. PMID:23825576

Villalobos-Duno, Héctor; San-Blas, Gioconda; Paulinkevicius, Maryan; Sánchez-Martín, Yolanda; Nino-Vega, Gustavo

2013-01-01

42

Structural and Topographic Dynamics of Pulmonary Histopathology and Local Cytokine Profiles in Paracoccidioides brasiliensis Conidia-Infected Mice  

PubMed Central

Background Paracoccidioidomycosis (PCM), an endemic systemic mycosis caused by the fungus Paracoccidioides brasiliensis (Pb), usually results in severe lung damage in patients. Methods and Findings Considering the difficulties to sequentially study the infection in humans, this work was done in mice inoculated intranasally with infective Pb-conidia. Lungs of control and Pb-infected mice were studied after 2-hours, 4, 8, 12 and 16-weeks post-infection (p.i) in order to define histopathologic patterns of pulmonary lesions, multiplex-cytokine profiles and their dynamics during the course of this mycosis. Besides the nodular/granulomatous lesions previously informed, results revealed additional non-formerly described lung abnormalities, such as periarterial sheath inflammation and pseudotumoral masses. The following chronologic stages occurring during the course of the experimental infection were defined: Stage one (2-hours p.i): mild septal infiltration composed by neutrophils and macrophages accompanied by an intense “cytokine burst” represented by significant increases in IL-1?, IL-1?, IL-4, IL-5, IL-6, IL-10, IL12p70, IL-13, IL-17, Eotaxin, G-CSF, MCP1, MIP1?, GM-CSF, IFN-?, MIP1? and TNF? levels. Stage two (4-weeks p.i): presence of nodules, evidence of incipient periarterial- and intense but disperse parenchymal- inflammation, abnormalities that continued to be accompanied by hyper-secretion of those cytokines and chemokines mentioned in the first stage of infection. Stages three and four (8 and 12-weeks p.i.): fungal proliferation, inflammation and collagenesis reached their highest intensity with particular involvement of the periarterial space. Paradoxically, lung cytokines and chemokines were down-regulated with significant decreases in IL-2,IL-3,IL-5,IL-9,IL-13,IL-15,GM-CSF,IFN-?,MIP1? and TNF?. Stage five (16-weeks p.i.): inflammation decreased becoming limited to the pseudotumoral masses and was accompanied by a “silent” cytokine response, except for PDGF, MIG, RANTES and IL12p40 which remained up-regulated for the duration of the experiment. Conclusions Results of this study identified both classic and novel patterns corresponding to histopathologic and immunologic responses occurring during the course of experimental PCM. PMID:21765962

Cruz, Oswaldo G.; Restrepo, Angela; Cano, Luz Elena; Lenzi, Henrique Leonel

2011-01-01

43

Phylogenetic and evolutionary aspects of Paracoccidioides brasiliensis reveal a long coexistence with animal hosts that explain several biological features of the pathogen.  

PubMed

The habitat of the mycelial saprobic form of Paracoccidioides brasiliensis, which produces the infectious propagula, has not been determined and has proven difficult for mycologists to describe. The fungus has been rarely isolated from the environment, the disease has a prolonged latency period and no outbreaks have been reported. These facts have precluded the adoption of preventive measures to avoid infection. The confirmation of natural infections in nine-banded armadillos (Dasypus novemcinctus) with P. brasiliensis, in high frequency and wide geographic distribution, has opened new avenues for the study and understanding of its ecology. Armadillos belong to the order Xenarthra, which has existed in South America ever since the Paleocene Era (65 million years ago), when the South American subcontinent was still a detached land, before the consolidation of what is now known as the American continent. On the other hand, strong molecular evidence suggests that P. brasiliensis and other dimorphic pathogenic fungi--such as Blastomyces dermatitidis, Coccidioides immitis and Histoplasma capsulatum--belong to the family Onygenaceae sensu lato (order Onygenales, Ascomycota), which appeared around 150 million years ago. P. brasiliensis ecology and relation to its human host are probably linked to the fungal evolutionary past, especially its long coexistence with and adaptation to animal hosts other than Homo sapiens, of earlier origin. Instead of being a blind alley, the meaning of parasitism for dimorphic pathogenic fungi should be considered as an open two-way avenue, in which the fungus may return to the environment, therefore contributing to preserve its teleomorphic (sexual) and anamorphic (asexual) forms in a defined and protected natural habitat. PMID:16473563

Bagagli, Eduardo; Bosco, Sandra M G; Theodoro, Raquel Cordeiro; Franco, Marcello

2006-09-01

44

Influence of 17?-Estradiol on Gene Expression of Paracoccidioides during Mycelia-to-Yeast Transition  

PubMed Central

Background Paracoccidioides is the causative agent of paracoccidioidomycosis, a systemic mycosis endemic to Latin America. Infection is initiated by inhalation of conidia (C) or mycelial (M) fragments, which subsequently differentiate into yeast (Y). Epidemiological studies show a striking predominance of paracoccidioidomycosis in adult men compared to premenopausal women. In vitro and in vivo studies suggest that the female hormone (17?-estradiol, E2) regulates or inhibits M-or-C-to-Y transition. In this study we have profiled transcript expression to understand the molecular mechanism of how E2 inhibits M-to-Y transition. Methodology We assessed temporal gene expression in strain Pb01 in the presence or absence of E2 at various time points through 9 days of the M-to-Y transition using an 11,000 element random-shear genomic DNA microarray and verified the results using quantitative real time-PCR. E2-regulated clones were sequenced to identify genes and biological function. Principal Findings E2-treatment affected gene expression of 550 array elements, with 331 showing up-regulation and 219 showing down-regulation at one or more time points (p?0.001). Genes with low expression after 4 or 12 h exposure to E2 belonged to pathways involved in heat shock response (hsp90 and hsp70), energy metabolism, and several retrotransposable elements. Y-related genes, ?-1,3-glucan synthase, mannosyltransferase and Y20, demonstrated low or delayed expression in E2-treated cultures. Genes potentially involved in signaling, such as palmitoyltransferase (erf2), small GTPase RhoA, phosphatidylinositol-4-kinase, and protein kinase (serine/threonine) showed low expression in the presence of E2, whereas a gene encoding for an arrestin domain-containing protein showed high expression. Genes related to ubiquitin-mediated protein degradation, and oxidative stress response genes were up-regulated by E2. Conclusion This study characterizes the effect of E2 at the molecular level on the inhibition of the M-to-Y transition and is indicative that the inhibitory actions of E2 may be working through signaling genes that regulate dimorphism. PMID:22194832

Shankar, Jata; Wu, Thomas D.; Clemons, Karl V.; Monteiro, Jomar P.; Mirels, Laurence F.; Stevens, David A.

2011-01-01

45

Pseudozyma brasiliensis sp. nov., a xylanolytic, ustilaginomycetous yeast species isolated from an insect pest of sugarcane roots.  

PubMed

A novel ustilaginomycetous yeast isolated from the intestinal tract of an insect pest of sugarcane roots in Ribeirão Preto, São Paulo State, Brazil, represents a novel species of the genus Pseudozyma based on molecular analyses of the D1/D2 rDNA large subunit and the internal transcribed spacer (ITS1+ITS2) regions. The name Pseudozyma brasiliensis sp. nov. is proposed for this species, with GHG001(T) (?=?CBS 13268(T)?=?UFMG-CM-Y307(T)) as the type strain. P. brasiliensis sp. nov. is a sister species of Pseudozyma vetiver, originally isolated from leaves of vetiver grass and sugarcane in Thailand. P. brasiliensis sp. nov. is able to grow well with xylan as the sole carbon source and produces high levels of an endo-1,4-xylanase that has a higher specific activity in comparison with other eukaryotic xylanases. This enzyme has a variety of industrial applications, indicating the great biotechnological potential of P. brasiliensis. PMID:24682702

Oliveira, Juliana Velasco de Castro; Borges, Thuanny A; Corrêa dos Santos, Renato Augusto; Freitas, Larissa F D; Rosa, Carlos Augusto; Goldman, Gustavo Henrique; Riaño-Pachón, Diego Mauricio

2014-06-01

46

Paracoccidioides brasiliensis Vaccine Formulations Based on the gp43Derived P10 Sequence and the Salmonella enterica FliC Flagellin  

Microsoft Academic Search

Paracoccidioidomycosis (PCM) is a systemic granulomatous disease caused by the dimorphic fungus Para- coccidioides brasiliensis. Anti-PCM vaccine formulations based on the secreted fungal cell wall protein (gp43) or the derived P10 sequence containing a CD4 T-cell-specific epitope have shown promising results. In the present study, we evaluated new anti-PCM vaccine formulations based on the intranasal administration of P. brasiliensis gp43

Catarina J. M. Braga; Glauce M. G. Rittner; Julian E. Munoz Henao; Aline F. Teixeira; Liliana M. Massis; Maria E. Sbrogio-Almeida; Carlos P. Taborda; Luiz R. Travassos; Luís C. S. Ferreira

2009-01-01

47

Polymorphism in the flanking regions of the PbGP43 gene from the human pathogen Paracoccidioides brasiliensis: search for protein binding sequences and poly(A) cleavage sites  

PubMed Central

Background Paracoccidioides brasiliensis is a thermo-dimorphic fungus that causes paracoccidiodomycosis (PCM). Glycoprotein gp43 is the fungal main diagnostic antigen, which can also protect against murine PCM and interact with extracellular matrix proteins. It is structurally related to glucanases, however not active, and whose expression varies considerably. We have presently studied polymorphisms in the PbGP43 flanking regions to help understand such variations. Results we tested the protein-binding capacity of oligonucleotides covering the PbGP43 proximal 5' flanking region, including overlap and mutated probes. We used electrophoretic mobility shift assays and found DNA binding regions between positions -134 to -103 and -255 to -215. Only mutation at -230, characteristic of P. brasiliensis phylogenetic species PS2, altered binding affinity. Next, we cloned and sequenced the 5' intergenic region up to position -2,047 from P. brasiliensis Pb339 and observed that it is composed of three tandem repetitive regions of about 500 bp preceded upstream by 442 bp. Correspondent PCR fragments of about 2,000 bp were found in eight out of fourteen isolates; in PS2 samples they were 1,500-bp long due to the absence of one repetitive region, as detected in Pb3. We also compared fifty-six PbGP43 3' UTR sequences from ten isolates and have not observed polymorphisms; however we detected two main poly(A) clusters (1,420 to 1,441 and 1,451 to 1,457) of multiple cleavage sites. In a single isolate we found one to seven sites. Conclusions We observed that the amount of PbGP43 transcripts accumulated in P. brasiliensis Pb339 grown in defined medium was about 1,000-fold higher than in Pb18 and 120-fold higher than in Pb3. We have described a series of features in the gene flanking regions and differences among isolates, including DNA-binding sequences, which might impact gene regulation. Little is known about regulatory sequences in thermo-dimorphic fungi. The peculiar structure of tandem repetitive fragments in the 5' intergenic region of PbGP43, their characteristic sequences, besides the presence of multiple poly(A) cleavage sites in the 3' UTR will certainly guide future studies. PMID:20042084

2009-01-01

48

A Morphological and Cytochemical Study of the Interaction between Paracoccidiodes brasiliensis and Neutrophils  

NASA Astrophysics Data System (ADS)

Paracoccidioidomycosis is a systemic granulomatous disease caused by the dimorphic fungus Paracoccidioides brasiliensis. It is the most prevalent systemic mycosis of Latin America and 80% of the reported cases are from Brazil. Because of the great number of neutrophils found in the P. brasiliensis granuloma, studies have been done to evaluate the role of these cells during the development of the infection. Scanning and transmission electron microscopy of thin sections showed that the neutrophils ingest yeast cells through a typical phagocytic process with the formation of pseudopodes. The pseudopodes even disrupt the connection established between the mother and the bud cells. Neutrophils also associate to each other, forming a kind of extracellular vacuole where large yeast cells are encapsulated. Cytochemical studies showed that once P. brasiliensis attaches to the neutrophil surface, it triggers a respiratory burst with release of oxygen-derived products. Attachment also triggers neutrophils' degranulation, with release of endogenous peroxidase localized in cytoplasmic granules. Together, these processes lead to killing of both ingested and extracellular P. brasiliensis.

Dias, Maria Fernanda R. G.; Filgueira, Absalom L.; de Souza, Wanderley

2004-04-01

49

Identification and characterization of Tc1\\/mariner-like DNA transposons in genomes of the pathogenic fungi of the Paracoccidioides species complex  

Microsoft Academic Search

BACKGROUND: Paracoccidioides brasiliensis (Eukaryota, Fungi, Ascomycota) is a thermodimorphic fungus, the etiological agent of paracoccidioidomycosis, the most important systemic mycoses in Latin America. Three isolates corresponding to distinct phylogenetic lineages of the Paracoccidioides species complex had their genomes sequenced. In this study the identification and characterization of class II transposable elements in the genomes of these fungi was carried out.

Marjorie M Marini; Tamiris Zanforlin; Patrícia C Santos; Roberto RM Barros; Rosana Puccia; Maria SS Felipe; Marcelo Brigido; Célia MA Soares; Jerônimo C Ruiz; José F Silveira; Patrícia S Cisalpino

2010-01-01

50

P. brasiliensis Virulence Is Affected by SconC, the Negative Regulator of Inorganic Sulfur Assimilation  

PubMed Central

Conidia/mycelium-to-yeast transition of Paracoccidioidesbrasiliensis is a critical step for the establishment of paracoccidioidomycosis, a systemic mycosis endemic in Latin America. Thus, knowledge of the factors that mediate this transition is of major importance for the design of intervention strategies. So far, the only known pre-requisites for the accomplishment of the morphological transition are the temperature shift to 37°C and the availability of organic sulfur compounds. In this study, we investigated the auxotrophic nature to organic sulfur of the yeast phase of Paracoccidioides, with special attention to P. brasiliensis species. For this, we addressed the role of SconCp, the negative regulator of the inorganic sulfur assimilation pathway, in the dimorphism and virulence of this pathogen. We show that down-regulation of SCONC allows initial steps of mycelium-to-yeast transition in the absence of organic sulfur compounds, contrarily to the wild-type fungus that cannot undergo mycelium-to-yeast transition under such conditions. However, SCONC down-regulated transformants were unable to sustain yeast growth using inorganic sulfur compounds only. Moreover, pulses with inorganic sulfur in SCONC down-regulated transformants triggered an increase of the inorganic sulfur metabolism, which culminated in a drastic reduction of the ATP and NADPH cellular levels and in higher oxidative stress. Importantly, the down-regulation of SCONC resulted in a decreased virulence of P. brasiliensis, as validated in an in vivo model of infection. Overall, our findings shed light on the inability of P. brasiliensis yeast to rely on inorganic sulfur compounds, correlating its metabolism with cellular energy and redox imbalances. Furthermore, the data herein presented reveal SconCp as a novel virulence determinant of P. brasiliensis. PMID:24066151

Menino, Joao Filipe; Saraiva, Margarida; Gomes-Rezende, Jessica; Sturme, Mark; Pedrosa, Jorge; Castro, Antonio Gil; Ludovico, Paula; Goldman, Gustavo H.; Rodrigues, Fernando

2013-01-01

51

Occurrence of Paracoccidioides lutzii in the Amazon region: description of two cases.  

PubMed

Paracoccidioidomycosis (PCM), the most important human systemic mycosis in Latin America, is known to be caused by at least four different phylogenetic lineages within the Paracoccidioides brasiliensis complex, including S1, PS2, PS3, and Pb01-like group. Herein, we describe two cases of PCM in patients native from the Amazon region. The disease was originally thought to have been caused by P. brasiliensis. Despite the severity of the cases, sera from the patients were negative in immunodiffusion tests using the standard exoantigen from P. brasiliensis B-339. However, a positive response was recorded with an autologous preparation of Paracoccidioides lutzii exoantigen. A phylogenetic approach based on the gp43 and ARF loci revealed high similarity between our clinical isolates and the Pb01-like group. The occurrence of PCM caused by P. lutzii in the Brazilian Amazon (Pará State) was thus proven. The incidence of PCM caused by P. lutzii may be underestimated in northern Brazil. PMID:22927496

Marques-da-Silva, Silvia Helena; Rodrigues, Anderson Messias; de Hoog, G Sybren; Silveira-Gomes, Fabíola; Camargo, Zoilo Pires de

2012-10-01

52

Intermolecular interactions of the malate synthase of Paracoccidioides spp  

PubMed Central

Background The fungus Paracoccidioides spp is the agent of paracoccidioidomycosis (PCM), a pulmonary mycosis acquired by the inhalation of fungal propagules. Paracoccidioides malate synthase (PbMLS) is important in the infectious process of Paracoccidioides spp because the transcript is up-regulated during the transition from mycelium to yeast and in yeast cells during phagocytosis by murine macrophages. In addition, PbMLS acts as an adhesin in Paracoccidioides spp. The evidence for the multifunctionality of PbMLS indicates that it could interact with other proteins from the fungus and host. The objective of this study was to identify and analyze proteins that possibly bind to PbMLS (PbMLS-interacting proteins) because protein interactions are intrinsic to cell processes, and it might be possible to infer the function of a protein through the identification of its ligands. Results The search for interactions was performed using an in vivo assay with a two-hybrid library constructed in S. cerevisiae; the transcripts were sequenced and identified. In addition, an in vitro assay using pull-down GST methodology with different protein extracts (yeast, mycelium, yeast-secreted proteins and macrophage) was performed, and the resulting interactions were identified by mass spectrometry (MS). Some of the protein interactions were confirmed by Far-Western blotting using specific antibodies, and the interaction of PbMLS with macrophages was validated by indirect immunofluorescence and confocal microscopy. In silico analysis using molecular modeling, dynamics and docking identified the amino acids that were involved in the interactions between PbMLS and PbMLS-interacting proteins. Finally, the interactions were visualized graphically using Osprey software. Conclusion These observations indicate that PbMLS interacts with proteins that are in different functional categories, such as cellular transport, protein biosynthesis, modification and degradation of proteins and signal transduction. These data suggest that PbMLS could play different roles in the fungal cell. PMID:23672539

2013-01-01

53

Phylogenetic analysis reveals a high level of speciation in the Paracoccidioides genus.  

PubMed

Paracoccidioidomycosis (PCM) is a systemic disease endemic to most of Latin America, with greatest impact in rural areas. The taxonomic status of one of the best studied Paracoccidioides isolates (Pb01) as P. brasiliensis remains unresolved due to its genomic differences from the other three previously described phylogenetic species (S1, PS2 and PS3; Carrero et al., 2008. Fungal Genet. Biol. 45, 605). Using the genealogic concordance method of phylogenetic species recognition (GCPSR) via maximum parsimony and Bayesian analysis, we identified a clade of 17 genotypically similar isolates, including Pb01, which are distinct from the S1/PS2/P3 clade. Consistent with GCPSR, this "Pb01-like" group can be considered a new phylogenetic species, since it is strongly supported by all independent and concatenated genealogies. "Pb01-like" species exhibit great sequence and morphological divergence from the S1/PS2/PS3 species clade, and we estimate that these groups last shared a common ancestor approximately 32 million years ago. In addition, recombination analysis revealed independent events inside both main groups suggesting reproductive isolation. Consequently, we recommend the formal description of the "Pb01-like" cluster as the new species Paracoccidioides lutzii, a tribute to Adolpho Lutz, discoverer of P. brasiliensis in 1908. PMID:19376249

Teixeira, Marcus M; Theodoro, Raquel C; de Carvalho, Maria J A; Fernandes, Larissa; Paes, Hugo C; Hahn, Rosane C; Mendoza, Leonel; Bagagli, Eduardo; San-Blas, Gioconda; Felipe, Maria Sueli S

2009-08-01

54

Comparative proteomics in the genus Paracoccidioides.  

PubMed

The genus Paracoccidioides comprises a complex of phylogenetic species of dimorphic pathogenic fungi, the etiologic agents of paracoccidioidomycosis (PCM), a disease confined to Latin America and of marked relevance in its endemic areas due to its high frequency and severity. The members of the Paracoccidioides genus are distributed in distinct phylogenetic species (S1, PS2, PS3 and 01-like) that potentially differ in their biochemical and molecular characteristics. In this work, we performed the proteomic characterization of different members of the genus Paracoccidioides. We compared the proteomic profiles of Pb01 (01-like), Pb2 (PS2), Pb339 (S1) and PbEPM83 (PS3) using 2D electrophoresis and mass spectrometry. The proteins/isoforms were selected based on the staining intensity of the spots as determined by image analysis. The proteins/isoforms were in-gel digested and identified by peptide mass fingerprinting and ion fragmentation. A total of 714 spots were detected, of which 343 were analyzed. From these spots, 301 represented differentially expressed proteins/isoforms among the four analyzed isolates, as determined by ANOVA. After applying the FDR correction, a total of 267 spots were determined to be differentially expressed. From the total, 193 proteins/isoforms were identified by PMF and confirmed by ion fragmentation. Comparing the expression profiles of the isolates, the proteins/isoforms that were related to glycolysis/gluconeogenesis and to alcohol fermentation were more abundant in Pb01 than in other representatives of the genus Paracoccidioides, indicating ahigher use of anaerobic pathways for energy production. Those enzymes related to the oxidative stress response were more abundant in Pb01, Pb2 and Pb339, indicating a better response to ROS in these members of the Paracoccidioides complex. The enzymes of the pentose phosphate pathway were abundant in Pb2. Antigenic proteins, such as GP43 and a 27-kDa antigenic protein, were less abundant in Pb01 and Pb2. The proteomic profile indicates metabolic differences among the analyzed members of the Paracoccidioides genus. PMID:23911955

Pigosso, Laurine Lacerda; Parente, Ana Flávia Alves; Coelho, Alexandre Siqueira Guedes; Silva, Luciano Paulino; Borges, Clayton Luiz; Bailão, Alexandre Melo; Soares, Célia Maria de Almeida

2013-11-01

55

Inhibition of Paracoccidioides lutzii Pb01 Isocitrate Lyase by the Natural Compound Argentilactone and Its Semi-Synthetic Derivatives  

PubMed Central

The dimorphic fungus Paracoccidioides spp. is responsible for paracoccidioidomycosis, the most prevalent systemic mycosis in Latin America, causing serious public health problems. Adequate treatment of mycotic infections is difficult, since fungi are eukaryotic organisms with a structure and metabolism similar to those of eukaryotic hosts. In this way, specific fungus targets have become important to search of new antifungal compound. The role of the glyoxylate cycle and its enzymes in microbial virulence has been reported in many fungal pathogens, including Paracoccidioides spp. Here, we show the action of argentilactone and its semi-synthetic derivative reduced argentilactone on recombinant and native isocitrate lyase from Paracoccidioides lutzii Pb01 (PbICL) in the presence of different carbon sources, acetate and glucose. Additionally, argentilactone and its semi-synthetic derivative reduced argentilactone exhibited relevant inhibitory activity against P. lutzii Pb01 yeast cells and dose-dependently influenced the transition from the mycelium to yeast phase. The other oxygenated derivatives tested, epoxy argentilactone and diol argentilactone-, did not show inhibitory action on the fungus. The results were supported by in silico experiments. PMID:24752170

do Prado, Renata Silva; Alves, Ricardo Justino; de Oliveira, Cecilia Maria Alves; Kato, Lucilia; da Silva, Roosevelt Alves; Quintino, Guilherme Oliveira; do Desterro Cunha, Silvio; de Almeida Soares, Celia Maria; Pereira, Maristela

2014-01-01

56

Melanin as a virulence factor of Paracoccidioides brasiliensis and other dimorphic pathogenic fungi: a minireview  

Microsoft Academic Search

Melanin pigments are substances produced by a broad variety of pathogenic microorganisms, including bacteria, fungi, and helminths.\\u000a Microbes predominantly produce melanin pigment via tyrosinases, laccases, catecholases, and the polyketide synthase pathway.\\u000a In fungi, melanin is deposited in the cell wall and cytoplasm, and melanin particles (“ghosts”) can be isolated from these\\u000a fungi that have the same size and shape of

Carlos P. Taborda; Marcelo B. da Silva; Joshua D. Nosanchuk; Luiz R. Travassos

2008-01-01

57

Cryptic Speciation and Recombination in the Fungus Paracoccidioides brasiliensis as Revealed by Gene Genealogies  

E-print Network

with six isolates), and PS3 (phylogenetic species 3 with 21 isolates). Genealogies of four of the regions. The second clade, PS3, composed solely of 21 Colombian isolates, was strongly supported by the a

58

Factors associated with Paracoccidiodes brasiliensis infection among permanent residents of three endemic areas in Colombia.  

PubMed Central

The natural habitat of Paracoccidioides brasiliensis, the aetiologic agent of paracoccidioidomycosis, has not been determined. Consequently, the events leading to the acquisition of infection remain controversial. To identify factors associated with infection in endemic areas we conducted a survey in three rural communities in Colombia where we had previously diagnosed paracoccidioidomycosis in children. Permanent residents were surveyed taking into consideration environmental and occupational variables. Skin tests were used to classify subjects as infected or non-infected. Variables found associated with infection were: (i) community A: previous residence around Porce river and agriculture in vegetable gardens; (ii) community C: frequent use of specific water sources; (iii) community V: housekeeping activities, and (iv) total group: age > 25 years and contact with bats. Residents in communities with higher prevalence of infection were older, had more complex residence history, and referred more contact with armadillos than residents of communities with lower infection. PMID:8348926

Cadavid, D.; Restrepo, A.

1993-01-01

59

Hydroxynitrile lyase from Hevea brasiliensis: molecular characterization and mechanism of enzyme catalysis.  

PubMed

(S)-Hydroxynitrile lyase (Hnl) from the tropical rubber tree Hevea brasiliensis is a 29 kDa single chain protein that catalyses the breakdown or formation of a C--C bond by reversible addition of hydrocyanic acid to aldehydes or ketones. The primary sequence of Hnl has no significant homology to known proteins. Detailed homology investigations employing PROFILESEARCH and secondary structure prediction algorithms suggest that Hnl is a member of the alpha/beta hydrolase fold protein family and contains a catalytic triad as functional residues for catalysis. The significance of predicted catalytic residues was tested and confirmed by site-directed mutagenesis and expression of mutant and wild-type proteins in the yeast, Saccharomyces cerevisiae. Based on these data we suggest a mechanistic model for the (S)-cyanohydrin synthesis catalyzed by hydroxynitrile lyase from Hevea brasiliensis. PMID:9094745

Hasslacher, M; Kratky, C; Griengl, H; Schwab, H; Kohlwein, S D

1997-03-01

60

Characterization of HbWRKY1, a WRKY transcription factor from Hevea brasiliensis that negatively regulates HbSRPP.  

PubMed

Small rubber particle protein (SRPP) is a major component of Hevea brasiliensis (H. brasiliensis) latex, which is involved in natural rubber (NR) biosynthesis. However, little information is available on the regulation of SRPP gene (HbSRPP) expression. To study the transcriptional regulation of HbSRPP, the yeast one-hybrid experiment was performed to screen the latex cDNA library using the HbSRPP promoter as bait. One cDNA that encodes the WRKY transcription factor, designated as HbWRKY1, was isolated from H. brasiliensis. HbWRKY1 contains a 1437 bp open reading frame that encodes 478 amino acids. The deduced HbWRKY1 protein was predicted to possess two conserved WRKY domains and a C2H2 zinc-finger motif. HbWRKY1 was expressed at different levels, with the highest transcription in the flower, followed by the bark, latex, and leaf. Furthermore, the co-expression of pHbSRP::GUS with CaMV35S::HbWRKY1 significantly decreased the GUS activity in transgenic tobacco, indicating that HbWRKY1 significantly suppressed the HbSRPP promoter. These results suggested that HbWRKY1 maybe a negative transcription regulator of HbSRPP involved in NR biosynthesis in H. brasiliensis. PMID:23988297

Wang, Ying; Guo, Dong; Li, Hui-Liang; Peng, Shi-Qing

2013-10-01

61

Genetic Diversity of Pectobacterium carotovorum subsp. brasiliensis Isolated in Korea  

PubMed Central

The plant pathogenic bacterial genus Pectobacteirum consists of heterogeneous strains. The P. carotovorum species is a complex strain showing divergent characteristics, and a new subspecies named P. carotovorum subsp. brasiliensis has been identified recently. In this paper, we re-identified the P. carotovorum subsp. brasiliensis isolates from those classified under the subspecies carotovorum and newly isolated P. carotovorum subsp. brasiliensis strains. All isolates were able to produce plant cell-wall degrading enzymes such as pectate lyase, polygalacturonase, cellulase and protease. We used genetic and biochemical methods to examine the diversity of P. carotovorum subsp. brasiliensis isolates, and found genetic diversity within the brasiliensis subsp. isolates in Korea. The restriction fragment length polymorphism analysis based on the recA gene revealed a unique pattern for the brasiliensis subspecies. The Korean brasiliensis subsp. isolates were divided into four clades based on pulsed-field gel electrophoresis. However, correlations between clades and isolated hosts or year could not be found, suggesting that diverse brasiliensis subsp. isolates existed. PMID:25288994

Lee, Dong Hwan; Kim, Jin-Beom; Lim, Jeong-A; Han, Sang-Wook; Heu, Sunggi

2014-01-01

62

Yeast Infections  

MedlinePLUS

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

63

Susceptibility of species within the Sporothrix schenckii complex to a panel of killer yeasts.  

PubMed

The Sporothrix schenckii complex is the etiologic agent of sporotrichosis, a subacute or chronic mycosis which can affect humans and animals. Killer yeasts have been used in the medical field for development of novel antimycotics and biotyping of pathogenic fungi. The action of 18 killer yeasts on the growth of 88 characterized S. schenckii, Sporothrix globosa, Sporothrix brasiliensis, and Sporothrix mexicana clinical and environmental isolates was evaluated. Killer studies were performed on Petri dishes containing cheese black starch agar. The yeasts Candida catenulata (QU26, QU31, QU127, LV102); Trichosporon faecale (QU100); Trichosporon japonicum (QU139); Kluyveromyces lactis (QU30, QU99, QU73); Kazachstania unispora (QU49), Trichosporon insectorum (QU89), and Kluyveromyces marxianus (QU103) showed activity against all strains of the S. schenckii complex tested. Observation by optical microscopy of S. brasiliensis 61 within the inhibition haloes around the colonies of the killer yeasts QU100, QU139, and LV102 showed that there was no conidiation, but there was hyphal proliferation. The toxins were fungistatic against S. brasiliensis 61. There was no difference in susceptibility to the toxins among the S. schenckii species complex. Further investigations are necessary to clearly establish the mechanism of action of the toxins. PMID:23686831

Stopiglia, Cheila Denise Ottonelli; Heidrich, Daiane; Sorrentino, Julia Medeiros; Vieira, Fabiane Jamono; Landell, Melissa Fontes; Valente, Patrícia; Scroferneker, Maria Lúcia

2014-06-01

64

Rubber Tree (Hevea brasiliensis Muell. Arg).  

PubMed

Rubber tree (Hevea brasiliensis Muell. Arg.) is an important industrial crop for natural rubber production. At present, more than 9.5 million hectares in about 40 countries are devoted to rubber tree cultivation with a production about 6.5 million tons of dry rubber each year. The world supply of natural rubber is barely keeping up with a global demand for 12 million tons of natural rubber in 2020. Tapping panel dryness (TPD) is a complex physiological syndrome widely found in rubber tree plantations, which causes severe yield and crop losses in natural rubber producing countries. Currently, there is no effective prevention or treatment for this serious malady. As it is a perennial tree crop, the integration of specific desired traits through conventional breeding is both time-consuming and labour-intensive. Genetic transformation with conventional breeding is certainly a more promising tool for incorporation of agronomically important genes that could improve existing Hevea genotype. This chapter provides an Agrobacterium-mediated transformation protocol for rubber tree using immature anther-derived calli as initial explants. We have applied this protocol to generate genetically engineered plants from a high yielding Indian clone RRII 105 of Hevea brasiliensis (Hb). Calli were co-cultured with Agrobacterium tumefaciens harboring a plasmid vector containing the Hb superoxide dismutase (SOD) gene and the reporter gene used was beta-glucuronidase (GUS) gene (uidA). The selectable marker gene used was neomycin phosphotransferase (nptII) and kanamycin was used as selection agent. We found that a suitable transformation protocol for Hevea consists of a 3-d co-cultivation with Agrobacterium in the presence of 20 mM acetosyringone, 15 mM betaine HCl, and 11.55 mM proline followed by selection on medium containing 300 mg/L kanamycin. Transformed calli surviving on medium containing 300 mg/L kanamycin showed a strong GUS-positive reaction. Upon subsequent subculture into fresh media, we obtained somatic embryogenesis and germinated plantlets, which were found to be GUS positive. The integration of uidA, nptII, and HbSOD transgenes into Hevea genome was confirmed by polymerase chain reaction (PCR) as well as Southern blot analysis. PMID:17033060

Venkatachalam, Perumal; Jayashree, Radha; Rekha, Karumamkandathil; Sushmakumari, Sreedharannair; Sobha, Sankaren; Kumari Jayasree, Parukkuttyamma; Kala, Radha Gopikkuttanunithan; Thulaseedharan, Arjunan

2006-01-01

65

MODELING DROUGHT IMPACT ON H. BRASILIENSIS TRANSPIRATION, GROWTH AND LATEX PRODUCTION OF A  

E-print Network

1 MODELING DROUGHT IMPACT ON H. BRASILIENSIS 2 TRANSPIRATION, GROWTH AND LATEX PRODUCTION OF A HEVEA BRASILIENSIS STAND FACING DROUGHT IN4 NORTHEAST THAILAND: THE USE OF THE WANULCAS MODEL for natural rubber, Hevea brasiliensis is16 increasingly planted in drought prone areas

Boyer, Edmond

66

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

67

Isolation of scopoletin from leaves of Hevea brasiliensis and the effect of scopoletin on pathogens of H. brasiliensis.  

PubMed

Scopoletin (7-hydroxy-6-methoxy coumarin) which inhibited the conidial germination of Corynespora cassiicola was isolated from the uninfected mature leaves of Hevea brasiliensis. Scopoletin was not detected in uninfected immature rubber leaves. The immature leaves produced scopoletin after being infected with C. cassiicola. The concentration of scopoletin in infected leaves was higher than in uninfected mature leaves. Scopoletin also inhibited the conidial germination of other fungal pathogens of H. brasiliensis. However, no correlation was observed between scopoletin accumulation and clonal resistance. PMID:12014480

Silva, W P K; Deraniyagala, S A; Wijesundera, R L C; Karunanayake, E H; Priyanka, U M S

2002-01-01

68

Mitochondrial DNA polymorphism and phylogenetic relationships in Hevea brasiliensis  

Microsoft Academic Search

Using fourteen random mitochondrial DNA probes, we have examined restriction fragment length polymorphism (RFLP) in wild and cultivatedHevea brasiliensis. A total of 395 accessions, including 345 from various prospectings collected in Brazil, Colombia and Peru and 50 cultivated clones, were analyzed. Two other species (H. benthamiana andH. pauciflora) were also included in the study for comparison. The high level of

Hong Luo; Benoît Van Coppenolle; Marc Seguin; Marc Boutry

1995-01-01

69

Draft genome sequence of the rubber tree Hevea brasiliensis  

PubMed Central

Background Hevea brasiliensis, a member of the Euphorbiaceae family, is the major commercial source of natural rubber (NR). NR is a latex polymer with high elasticity, flexibility, and resilience that has played a critical role in the world economy since 1876. Results Here, we report the draft genome sequence of H. brasiliensis. The assembly spans ~1.1 Gb of the estimated 2.15 Gb haploid genome. Overall, ~78% of the genome was identified as repetitive DNA. Gene prediction shows 68,955 gene models, of which 12.7% are unique to Hevea. Most of the key genes associated with rubber biosynthesis, rubberwood formation, disease resistance, and allergenicity have been identified. Conclusions The knowledge gained from this genome sequence will aid in the future development of high-yielding clones to keep up with the ever increasing need for natural rubber. PMID:23375136

2013-01-01

70

Polymorphic microsatellite loci from the endangered Giant Otter ( Pteronura brasiliensis)  

Microsoft Academic Search

We describe the first microsatellite loci isolated from the giant otter (Pteronura brasiliensis), an endangered mustelid endemic to South America. Fourteen di- and trinucleotide polymorphic loci were characterised in\\u000a fourteen individuals from the Pantanal wetlands, Central Brazil. Number of alleles per locus ranged from 2 to 5, and average\\u000a observed heterozygosity was 0.577. Two loci were in linkage disequilibrium, and

Carolina Ribas; Anderson V. Vasconcellos; Guilherme Mourão; William Magnusson; Antonio M. Solé-Cava; Haydée A. Cunha

71

Purification and characterization of hydroxynitrile lyase from Hevea brasiliensis  

Microsoft Academic Search

Hydroxynitrile lyase from Hevea brasiliensis (HbHNL) was purified to apparent homogeneity. Purified HbHNL consists of non-covalently linked monomers of 30 kDa. HbHNL exhibits a typical Michaelis-Menten kinetics with a Km of 115 mM and the enzyme activity is strongly inhibited by diisopropyl fluorophosphate and diethyl pyrocarbonate indicating a serine and histidine in the active site. HbHNL is serologically related to

Harald Wajant; Siegfried Förster

1996-01-01

72

High-level intracellular expression of hydroxynitrile lyase from the tropical rubber tree Hevea brasiliensis in microbial hosts.  

PubMed

(S)-Hydroxynitrile lyase (Hnl) from the tropical rubber tree Hevea brasiliensis catalyzes the formation of (S)-cyanohydrins from hydrocyanic acid and aldehydes or ketones. This enzyme accepts aliphatic, aromatic, and heterocyclic carbonyl compounds as substrates and is therefore considered a potent biocatalyst for the industrial production of optically active chemicals. Limitations in enzyme supply from natural resources were overcome by production of the enzyme in the microbial host systems Escherichia coli, Saccharomyces cerevisiae, and Pichia pastoris. Expression of Hnl in the prokaryotic system led to the formation of inclusion bodies whereas in both yeast hosts high levels of soluble protein were obtained. Highest yields were obtained in a high cell density batch fermentation of a P. pastoris transformant that expressed heterologous Hnl to about 50% of the soluble cytosolic protein. At a cell density of 100 g/liter cell dry weight, a volume yield of 22 g/liter of heterologous product was obtained. Attempts to produce the Hnl protein extracellularly with the yeast hosts by applying different leader peptide strategies were not successful. Immunofluorescence microscopy studies indicated that the secretion-directed heterologous Hnl protein accumulated in the plasma membrane forming aggregated clusters of inactive protein. PMID:9325140

Hasslacher, M; Schall, M; Hayn, M; Bona, R; Rumbold, K; Lückl, J; Griengl, H; Kohlwein, S D; Schwab, H

1997-10-01

73

Protein expression-yeast.  

PubMed

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

2014-01-01

74

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

75

Comparative genomic analysis of human fungal pathogens causing paracoccidioidomycosis.  

PubMed

Paracoccidioides is a fungal pathogen and the cause of paracoccidioidomycosis, a health-threatening human systemic mycosis endemic to Latin America. Infection by Paracoccidioides, a dimorphic fungus in the order Onygenales, is coupled with a thermally regulated transition from a soil-dwelling filamentous form to a yeast-like pathogenic form. To better understand the genetic basis of growth and pathogenicity in Paracoccidioides, we sequenced the genomes of two strains of Paracoccidioides brasiliensis (Pb03 and Pb18) and one strain of Paracoccidioides lutzii (Pb01). These genomes range in size from 29.1 Mb to 32.9 Mb and encode 7,610 to 8,130 genes. To enable genetic studies, we mapped 94% of the P. brasiliensis Pb18 assembly onto five chromosomes. We characterized gene family content across Onygenales and related fungi, and within Paracoccidioides we found expansions of the fungal-specific kinase family FunK1. Additionally, the Onygenales have lost many genes involved in carbohydrate metabolism and fewer genes involved in protein metabolism, resulting in a higher ratio of proteases to carbohydrate active enzymes in the Onygenales than their relatives. To determine if gene content correlated with growth on different substrates, we screened the non-pathogenic onygenale Uncinocarpus reesii, which has orthologs for 91% of Paracoccidioides metabolic genes, for growth on 190 carbon sources. U. reesii showed growth on a limited range of carbohydrates, primarily basic plant sugars and cell wall components; this suggests that Onygenales, including dimorphic fungi, can degrade cellulosic plant material in the soil. In addition, U. reesii grew on gelatin and a wide range of dipeptides and amino acids, indicating a preference for proteinaceous growth substrates over carbohydrates, which may enable these fungi to also degrade animal biomass. These capabilities for degrading plant and animal substrates suggest a duality in lifestyle that could enable pathogenic species of Onygenales to transfer from soil to animal hosts. PMID:22046142

Desjardins, Christopher A; Champion, Mia D; Holder, Jason W; Muszewska, Anna; Goldberg, Jonathan; Bailão, Alexandre M; Brigido, Marcelo Macedo; Ferreira, Márcia Eliana da Silva; Garcia, Ana Maria; Grynberg, Marcin; Gujja, Sharvari; Heiman, David I; Henn, Matthew R; Kodira, Chinnappa D; León-Narváez, Henry; Longo, Larissa V G; Ma, Li-Jun; Malavazi, Iran; Matsuo, Alisson L; Morais, Flavia V; Pereira, Maristela; Rodríguez-Brito, Sabrina; Sakthikumar, Sharadha; Salem-Izacc, Silvia M; Sykes, Sean M; Teixeira, Marcus Melo; Vallejo, Milene C; Walter, Maria Emília Machado Telles; Yandava, Chandri; Young, Sarah; Zeng, Qiandong; Zucker, Jeremy; Felipe, Maria Sueli; Goldman, Gustavo H; Haas, Brian J; McEwen, Juan G; Nino-Vega, Gustavo; Puccia, Rosana; San-Blas, Gioconda; Soares, Celia Maria de Almeida; Birren, Bruce W; Cuomo, Christina A

2011-10-01

76

Comparative Genomic Analysis of Human Fungal Pathogens Causing Paracoccidioidomycosis  

PubMed Central

Paracoccidioides is a fungal pathogen and the cause of paracoccidioidomycosis, a health-threatening human systemic mycosis endemic to Latin America. Infection by Paracoccidioides, a dimorphic fungus in the order Onygenales, is coupled with a thermally regulated transition from a soil-dwelling filamentous form to a yeast-like pathogenic form. To better understand the genetic basis of growth and pathogenicity in Paracoccidioides, we sequenced the genomes of two strains of Paracoccidioides brasiliensis (Pb03 and Pb18) and one strain of Paracoccidioides lutzii (Pb01). These genomes range in size from 29.1 Mb to 32.9 Mb and encode 7,610 to 8,130 genes. To enable genetic studies, we mapped 94% of the P. brasiliensis Pb18 assembly onto five chromosomes. We characterized gene family content across Onygenales and related fungi, and within Paracoccidioides we found expansions of the fungal-specific kinase family FunK1. Additionally, the Onygenales have lost many genes involved in carbohydrate metabolism and fewer genes involved in protein metabolism, resulting in a higher ratio of proteases to carbohydrate active enzymes in the Onygenales than their relatives. To determine if gene content correlated with growth on different substrates, we screened the non-pathogenic onygenale Uncinocarpus reesii, which has orthologs for 91% of Paracoccidioides metabolic genes, for growth on 190 carbon sources. U. reesii showed growth on a limited range of carbohydrates, primarily basic plant sugars and cell wall components; this suggests that Onygenales, including dimorphic fungi, can degrade cellulosic plant material in the soil. In addition, U. reesii grew on gelatin and a wide range of dipeptides and amino acids, indicating a preference for proteinaceous growth substrates over carbohydrates, which may enable these fungi to also degrade animal biomass. These capabilities for degrading plant and animal substrates suggest a duality in lifestyle that could enable pathogenic species of Onygenales to transfer from soil to animal hosts. PMID:22046142

Desjardins, Christopher A.; Champion, Mia D.; Holder, Jason W.; Muszewska, Anna; Goldberg, Jonathan; Bailao, Alexandre M.; Brigido, Marcelo Macedo; Ferreira, Marcia Eliana da Silva; Garcia, Ana Maria; Grynberg, Marcin; Gujja, Sharvari; Heiman, David I.; Henn, Matthew R.; Kodira, Chinnappa D.; Leon-Narvaez, Henry; Longo, Larissa V. G.; Ma, Li-Jun; Malavazi, Iran; Matsuo, Alisson L.; Morais, Flavia V.; Pereira, Maristela; Rodriguez-Brito, Sabrina; Sakthikumar, Sharadha; Salem-Izacc, Silvia M.; Sykes, Sean M.; Teixeira, Marcus Melo; Vallejo, Milene C.; Walter, Maria Emilia Machado Telles; Yandava, Chandri; Young, Sarah; Zeng, Qiandong; Zucker, Jeremy; Felipe, Maria Sueli; Goldman, Gustavo H.; Haas, Brian J.; McEwen, Juan G.; Nino-Vega, Gustavo; Puccia, Rosana; San-Blas, Gioconda; Soares, Celia Maria de Almeida; Birren, Bruce W.; Cuomo, Christina A.

2011-01-01

77

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. www.clontech.com Protocol # PT3024-1 2 Version # PR13103 I. Introduction 4 II. Introduction to Yeast Promoters 5 III. Culturing

Erickson, F. Les

78

[Yeasts contaminating salmon roe].  

PubMed

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

1996-01-01

79

YEAST GENETICS Fred Winston  

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

80

Revalidation and redescription of Triatoma brasiliensis macromelasoma Galv?o, 1956 and an identification key for the Triatoma brasiliensis complex (Hemiptera: Reduviidae: Triatominae)  

PubMed Central

Triatoma brasiliensis macromelasoma is revalidated based on the results of previous multidisciplinary studies on the Triatoma brasiliensis complex, consisting of crossing experiments and morphological, biological, ecological and molecular analyses. These taxonomic tools showed the closest relationship between T. b. macromelasoma and Triatoma brasiliensis brasiliensis. T. b. macromelasoma is redescribed based on specimens collected in the type locality and specimens from a F1 colony. The complex now comprises T. b. brasiliensis, T. b. macromelasoma, Triatoma melanica, Triatoma juazeirensis and Triatoma sherlocki. An identification key for all members of the complex is presented. This detailed comparative study of the morphological features of T. b. macromelasoma and the remaining members of the complex corroborates results from multidisciplinary analyses, suggesting that the subspecific status is applicable. This subspecies can be distinguished by the following combination of features: a pronotum with 1+1 narrow brownish-yellow stripes on the submedian carinae, not attaining its apex, hemelytra with membrane cells darkened on the central portion and legs with an incomplete brownish-yellow ring on the apical half of the femora. Because the T. brasiliensis complex is of distinct epidemiological importance throughout its geographic distribution, a precise identification of its five members is important for monitoring and controlling actions against Chagas disease transmission. PMID:24037202

Costa, Jane; Correia, Nathalia Cordeiro; Neiva, Vanessa Lima; Goncalves, Teresa Cristina Monte; Felix, Marcio

2013-01-01

81

Black yeast-like fungi associated with Lethargic Crab Disease (LCD) in the mangrove-land crab, Ucides cordatus (Ocypodidae).  

PubMed

Lethargic Crab Disease (LCD) caused extensive epizootic mortality of the mangrove land crab Ucides cordatus (Brachyura: Ocypodidae) along the Brazilian coast, mainly in the Northeastern region. The disease was named after the symptoms of slow movement of infected crabs. Causative agents were suspected to be two black yeast-like fungi of the family Herpotrichiellaceae (ascomycete order Chaetothyriales), judged by infected tissue biopsies from moribund U. cordatus. The aim of the present study is to prove that two species are involved in the disease: the recently described black yeast Exophiala cancerae, but also a less virulent, hitherto undescribed fonsecaea-like species, introduced here as the novel species Fonsecaea brasiliensis. Strains were identified by ITS rDNA sequencing, and species borderlines were established by multilocus sequencing and AFLP analysis. Fonsecaea brasiliensis proved to be closely related to the pathogenic species Cladophialophora devriesii which originally was isolated from a systemic infection in a human patient. The virulence of F. brasiliensis is lower than that of E. cancerae, as established by artificial inoculation of mangrove crabs. PMID:22440399

Vicente, Vania A; Orélis-Ribeiro, R; Najafzadeh, M J; Sun, Jiufeng; Guerra, Raquel Schier; Miesch, Stephanie; Ostrensky, Antonio; Meis, Jacques F; Klaassen, Corné H; de Hoog, G S; Boeger, Walter A

2012-07-01

82

Taxonomic and Functional Microbial Signatures of the Endemic Marine Sponge Arenosclera brasiliensis  

PubMed Central

The endemic marine sponge Arenosclera brasiliensis (Porifera, Demospongiae, Haplosclerida) is a known source of secondary metabolites such as arenosclerins A-C. In the present study, we established the composition of the A. brasiliensis microbiome and the metabolic pathways associated with this community. We used 454 shotgun pyrosequencing to generate approximately 640,000 high-quality sponge-derived sequences (?150 Mb). Clustering analysis including sponge, seawater and twenty-three other metagenomes derived from marine animal microbiomes shows that A. brasiliensis contains a specific microbiome. Fourteen bacterial phyla (including Proteobacteria, Cyanobacteria, Actinobacteria, Bacteroidetes, Firmicutes and Cloroflexi) were consistently found in the A. brasiliensis metagenomes. The A. brasiliensis microbiome is enriched for Betaproteobacteria (e.g., Burkholderia) and Gammaproteobacteria (e.g., Pseudomonas and Alteromonas) compared with the surrounding planktonic microbial communities. Functional analysis based on Rapid Annotation using Subsystem Technology (RAST) indicated that the A. brasiliensis microbiome is enriched for sequences associated with membrane transport and one-carbon metabolism. In addition, there was an overrepresentation of sequences associated with aerobic and anaerobic metabolism as well as the synthesis and degradation of secondary metabolites. This study represents the first analysis of sponge-associated microbial communities via shotgun pyrosequencing, a strategy commonly applied in similar analyses in other marine invertebrate hosts, such as corals and algae. We demonstrate that A. brasiliensis has a unique microbiome that is distinct from that of the surrounding planktonic microbes and from other marine organisms, indicating a species-specific microbiome. PMID:22768320

Trindade-Silva, Amaro E.; Rua, Cintia; Silva, Genivaldo G. Z.; Dutilh, Bas E.; Moreira, Ana Paula B.; Edwards, Robert A.; Hajdu, Eduardo; Lobo-Hajdu, Gisele; Vasconcelos, Ana Tereza; Berlinck, Roberto G. S.; Thompson, Fabiano L.

2012-01-01

83

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

1999-01-01

84

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

2009-01-01

85

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.

2012-01-01

86

Phylogenetic Analysis Reveals a High Prevalence of Sporothrix brasiliensis in Feline Sporotrichosis Outbreaks  

PubMed Central

Sporothrix schenckii, previously assumed to be the sole agent of human and animal sporotrichosis, is in fact a species complex. Recently recognized taxa include S. brasiliensis, S. globosa, S. mexicana, and S. luriei, in addition to S. schenckii sensu stricto. Over the last decades, large epidemics of sporotrichosis occurred in Brazil due to zoonotic transmission, and cats were pointed out as key susceptible hosts. In order to understand the eco-epidemiology of feline sporotrichosis and its role in human sporotrichosis a survey was conducted among symptomatic cats. Prevalence and phylogenetic relationships among feline Sporothrix species were investigated by reconstructing their phylogenetic origin using the calmodulin (CAL) and the translation elongation factor-1 alpha (EF1?) loci in strains originated from Rio de Janeiro (RJ, n?=?15), Rio Grande do Sul (RS, n?=?10), Paraná (PR, n?=?4), São Paulo (SP, n?=?3) and Minas Gerais (MG, n?=?1). Our results showed that S. brasiliensis is highly prevalent among cats (96.9%) with sporotrichosis, while S. schenckii was identified only once. The genotype of Sporothrix from cats was found identical to S. brasiliensis from human sources confirming that the disease is transmitted by cats. Sporothrix brasiliensis presented low genetic diversity compared to its sister taxon S. schenckii. No evidence of recombination in S. brasiliensis was found by split decomposition or PHI-test analysis, suggesting that S. brasiliensis is a clonal species. Strains recovered in states SP, MG and PR share the genotype of the RJ outbreak, different from the RS clone. The occurrence of separate genotypes among strains indicated that the Brazilian S. brasiliensis epidemic has at least two distinct sources. We suggest that cats represent a major host and the main source of cat and human S. brasiliensis infections in Brazil. PMID:23818999

Rodrigues, Anderson Messias; de Melo Teixeira, Marcus; de Hoog, G. Sybren; Schubach, Tania Maria Pacheco; Pereira, Sandro Antonio; Fernandes, Geisa Ferreira; Bezerra, Leila Maria Lopes; Felipe, Maria Sueli; de Camargo, Zoilo Pires

2013-01-01

87

Atomic resolution crystal structure of hydroxynitrile lyase from Hevea brasiliensis.  

PubMed

The X-ray crystal structure of native hydroxynitrile lyase from Hevea brasiliensis (Hb-HNL) has been determined at 1.1 A resolution. It refined to a final R of 11.5% for all data and an Rfree of 14.4%. The favorable data-to-parameter ratio at atomic resolution made the refinement of individual anisotropic displacement parameters possible. The data also allowed a clear distinction of the alternate orientations of all histidine and the majority of asparagine and glutamine side chains. A number of hydrogen atoms, including one on the imidazole of the mechanistically important His-235, became visible as peaks in a difference electron density map. The structure revealed a discretely disordered sidechain of Ser-80, which is part of the putative catalytic triad. Analysis of the anisotropy indicated an increased mobility of residues near the entrance to the active site and within the active site. PMID:10494852

Gruber, K; Gugganig, M; Wagner, U G; Kratky, C

1999-01-01

88

Drimanes from Drimys brasiliensis with leishmanicidal and antimalarial activity  

PubMed Central

This paper evaluates CHCl3 and CH3OH extracts of the stem bark, branches and leaves of Drimys brasiliensis and drimane sesquiterpenes isolated from the stem bark against strains of Leishmania amazonensis and Leishmania braziliensis promastigotes and Plasmodium falciparum trophozoites. All of the extracts and compounds were tested in cell lines in comparison with reference standards and cell viability was determined by the XTT method. The CHCl3 and CH3OH extracts from the stem bark and branches yielded promising results against two strains of Leishmania, with 50% inhibitory concentrations (IC50 ) values ranging from 39-100 µg/mL. The CHCl3 extract of the stem bark returned IC50 values of 39 and 40.6 µg/mL for L. amazonensis and L. braziliensis, respectively. The drimanes were relatively effective: 1-?-(p-coumaroyloxy)-polygodial produced IC50 values of 5.55 and 2.52 µM for L. amazonensis and L. braziliensis, respectively, compared with 1-?-(p-methoxycinnamoyl)-polygodial, which produced respective IC50 values of 15.85 and 17.80 µM. The CHCl3 extract demonstrated activity (IC50 of 3.0 µg/mL) against P. falciparum. The IC50 values of 1-?-(p-cumaroyloxyl)-polygodial and 1-?-(p-methoxycinnamoyl)-polygodial were 1.01 and 4.87 µM, respectively, for the trophozoite strain. Therefore, the results suggest that D. brasiliensis is a promising plant from which to obtain new and effective antiparasitic agents. PMID:23579790

Claudino, Vanessa Duarte; da Silva, Kesia Caroline; Cechinel, Valdir; Yunes, Rosendo Augusto; Monache, Franco Delle; Gimenez, Alberto; Salamanca, Efrain; Gutierrez-Yapu, David; Malheiros, Angela

2013-01-01

89

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

90

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

91

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

2004-01-01

92

Black yeast biota in the mangrove, in search of the origin of the lethargic crab disease (LCD).  

PubMed

Knowledge of natural ecology is essential for a better understanding of pathogenicity and opportunism in black yeast-like fungi. Although etiological agents of diseases caused by these fungi are supposed to originate from the environment, their isolation from nature is difficult. This is probably due to their oligotrophic nature, low competitive ability, and, overall, insufficient data on their natural habitat. We obtained environmental samples from mangrove areas where mortalities by lethargic crab disease (LCD) are reported and areas without disease recorded. Isolation of chaetothyrialean black yeasts and relatives was performed using a highly selective protocol. Species-specific primers were used to determine if these isolates represented Exophiala cancerae or Fonsecaea brasiliensis, two proven agents of LCD, in order to test hypotheses about the origin of the disease. Isolates, identified by morphology as Fonsecaea- or Exophiala-like, were tested specific diagnostic markers for the fungi associated with LCD. Although several black fungi were isolated, the main causative agent of the LCD, E. cancerae, was not found. Molecular markers for F. brasiliensis revealed 10 positive bands for isolates from biofilms on mangrove leaves, branches, and aerial roots, of which four were confirmed by ITS sequencing. The absence of E. cancerae in environmental samples suggests that the species is dependent on the crab, as a genuine pathogen, different from F. brasiliensis, which is probably not dependent on the host species, U. cordatus. However, we did not attempt isolation from the marine water, which may represent the pathway of dispersion of the black yeast species between neighbor mangroves. PMID:23539353

Guerra, Raquel Schier; do Nascimento, Mariana Machado Fidelis; Miesch, Stephanie; Najafzadeh, Mohammad Javad; Ribeiro, Raphael Orélis; Ostrensky, Antonio; de Hoog, Gerrit Sybren; Vicente, Vania Aparecida; Boeger, Walter A

2013-06-01

93

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.

94

RNAi in budding yeast.  

PubMed

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

2009-10-23

95

[Penicillium-inhibiting yeasts].  

PubMed

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

2004-01-01

96

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

97

Secreted Proteomes of Different Developmental Stages of the Gastrointestinal Nematode Nippostrongylus brasiliensis.  

PubMed

Hookworms infect more than 700 million people worldwide and cause more morbidity than most other human parasitic infections. Nippostrongylus brasiliensis (the rat hookworm) has been used as an experimental model for human hookworm because of its similar life cycle and ease of maintenance in laboratory rodents. Adult N. brasiliensis, like the human hookworm, lives in the intestine of the host and releases excretory/secretory products (ESP), which represent the major host-parasite interface. We performed a comparative proteomic analysis of infective larval (L3) and adult worm stages of N. brasiliensis to gain insights into the molecular bases of host-parasite relationships and determine whether N. brasiliensis could indeed serve as an appropriate model for studying human hookworm infections. Proteomic data were matched to a transcriptomic database assembled from 245,874,892 Illumina reads from different developmental stages (eggs, L3, L4, and adult) of N. brasiliensis yielding?18,426 unigenes with 39,063 possible isoform transcripts. From this analysis, 313 proteins were identified from ESPs by LC-MS/MS-52 in the L3 and 261 in the adult worm. Most of the proteins identified in the study were stage-specific (only 13 proteins were shared by both stages); in particular, two families of proteins-astacin metalloproteases and CAP-domain containing SCP/TAPS-were highly represented in both L3 and adult ESP. These protein families are present in most nematode groups, and where studied, appear to play roles in larval migration and evasion of the host's immune response. Phylogenetic analyses of defined protein families and global gene similarity analyses showed that N. brasiliensis has a greater degree of conservation with human hookworm than other model nematodes examined. These findings validate the use of N. brasiliensis as a suitable parasite for the study of human hookworm infections in a tractable animal model. PMID:24994561

Sotillo, Javier; Sanchez-Flores, Alejandro; Cantacessi, Cinzia; Harcus, Yvonne; Pickering, Darren; Bouchery, Tiffany; Camberis, Mali; Tang, Shiau-Choot; Giacomin, Paul; Mulvenna, Jason; Mitreva, Makedonka; Berriman, Matthew; LeGros, Graham; Maizels, Rick M; Loukas, Alex

2014-10-01

98

Draft Genome Sequence of Pseudozyma brasiliensis sp. nov. Strain GHG001, a High Producer of Endo-1,4-Xylanase Isolated from an Insect Pest of Sugarcane.  

PubMed

Here, we present the nuclear and mitochondrial genome sequences of Pseudozyma brasiliensis sp. nov. strain GHG001. P. brasiliensis sp. nov. is the closest relative of Pseudozyma vetiver. P. brasiliensis sp. nov. is capable of growing on xylose or xylan as a sole carbon source and has great biotechnological potential. PMID:24356824

Oliveira, Juliana Velasco de Castro; Dos Santos, Renato Augusto Corrêa; Borges, Thuanny A; Riaño-Pachón, Diego Mauricio; Goldman, Gustavo Henrique

2013-01-01

99

Assessment of plant lectin antifungal potential against yeasts of major importance in medical mycology.  

PubMed

The search for new compounds with antifungal activity is accelerating due to rising yeast and fungal resistance to commonly prescribed drugs. Among the molecules being investigated, plant lectins can be highlighted. The present work shows the potential of six plant lectins which were tested in vitro against yeasts of medical importance, Candida albicans, Candida tropicalis, Candida parapsilosis, Cryptococcus gattii, Cryptococcus neoformans, Malassezia pachydermatis, Rhodotorula sp. and Trichosporon sp. Broth microdilution susceptibility testing was performed in accordance with standard protocols to evaluate antifungal activity. Minimum inhibitory concentration (MIC) was determined at 80% yeast growth inhibition, whereas the minimum fungicidal concentration (MFC) was evaluated after making the subcultures of each dilution. Only C. parapsilosis growth was inhibited by the lectins tested. Abelmoschus esculentus lectin showed the highest MIC (0.97 ?g ml(-1)). Lectins from Canavalia brasiliensis, Mucuna pruriens and Clitoria fairchildiana presented the highest MFC at (3.90 ?g ml(-1)). These results encourage further studies with wider yeast strain selections, and open new perspectives for the development of pharmacological molecules. PMID:23161017

Klafke, Gabriel Baracy; Moreira, Gustavo Marçal Schmitt Garcia; Monte, Leonardo Garcia; Pereira, Juliano Lacava; Brandolt, Tchana Martinez; Xavier, Melissa Orzechowski; Santi-Gadelha, Tatiane; Dellagostin, Odir Antonio; Pinto, Luciano da Silva

2013-02-01

100

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.

2013-01-01

101

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

1990-01-01

102

Geodermatophilus brasiliensis sp. nov., isolated from Brazilian soil.  

PubMed

A Gram-reaction-positive bacterial isolate, designated Tü 6233(T), with rudimentary, coral-pink vegetative mycelium that formed neither aerial mycelium nor spores, was isolated from a Brazilian soil sample. Chemotaxonomic and molecular characteristics of the isolate matched those described for members of the genus Geodermatophilus. Cell-wall hydrolysates contained meso-diaminopimelic acid as the diagnostic diamino acid and galactose as the diagnostic sugar. The major fatty acids were iso-C(16?:?0), iso-C(15?:?0) and C(17?:?1)?8c and the predominant menaquinone was MK-9(H4). The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, hydroxyphosphatidylethanolamine, phosphatidylinositol, an unknown glycophospholipid and an unknown phospholipid. The DNA G+C content of the strain was 75.4 mol%. The 16S rRNA gene sequence identity with members of the genus Geodermatophilus was 94.2-98.7%. Based on phenotypic, chemotaxonomic and phylogenetic data, strain Tü 6233(T) is proposed to represent a novel species, Geodermatophilus brasiliensis sp. nov., with the type strain Tü 6233(T) (?=?DSM 44526(T)?=?CECT 8402(T)). PMID:24871776

Bertazzo, Marcelo; Montero-Calasanz, Maria del Carmen; Martinez-Garcia, Manuel; Spröer, Cathrin; Schumann, Peter; Kroppenstedt, Reiner M; Stackebrandt, Erko; Klenk, Hans-Peter; Fiedler, Hans-Peter

2014-08-01

103

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

1997-01-01

104

Diversity and antimicrobial potential of culturable heterotrophic bacteria associated with the endemic marine sponge Arenosclera brasiliensis  

PubMed Central

Marine sponges are the oldest Metazoa, very often presenting a complex microbial consortium. Such is the case of the marine sponge Arenosclera brasiliensis, endemic to Rio de Janeiro State, Brazil. In this investigation we characterized the diversity of some of the culturable heterotrophic bacteria living in association with A. brasiliensis and determined their antimicrobial activity. The genera Endozoicomonas (N = 32), Bacillus (N = 26), Shewanella (N = 17), Pseudovibrio (N = 12), and Ruegeria (N = 8) were dominant among the recovered isolates, corresponding to 97% of all isolates. Approximately one third of the isolates living in association with A. brasiliensis produced antibiotics that inhibited the growth of Bacillus subtilis, suggesting that bacteria associated with this sponge play a role in its health. PMID:25024903

Rua, Cintia P.J.; Trindade-Silva, Amaro E.; Appolinario, Luciana R.; Venas, Taina M.; Garcia, Gizele D.; Carvalho, Lucas S.; Lima, Alinne; Kruger, Ricardo; Pereira, Renato C.; Berlinck, Roberto G.S.; Valle, Rogerio A.B.; Thompson, Cristiane C.

2014-01-01

105

L-arabinose fermenting yeast  

DOEpatents

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)

2010-12-07

106

Mitochondrial assembly in yeast.  

PubMed

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

1999-06-01

107

Conservation genetics of the giant otter (Pteronura brasiliensis (Zimmerman, 1780)) (Carnivora, Mustelidae).  

PubMed

The giant otter (Pteronura brasiliensis) is an aquatic mammal of the Mustelidae family, endemic to South America. Its original distribution corresponds to the region from the Guyanas to Central-North Argentina, but it is extinct or on the verge of extinction in most of its historical range. Currently, the species is considered endangered by the World Conservation Union (IUCN). Based on its geographic distribution in the South American continent and on some morphological characters, two subspecies were suggested: P. brasiliensis brasiliensis, occurring in the Amazon and Orinoco River Basins, and P. brasiliensis paranensis, in the Paraná and Paraguai River Basins. However, there is no consensus on assuming this subspecies division and no detailed studies have been carried out to elucidate this question. This study aims to evaluate the genetic diversity and population structure of Pteronura brasiliensis along its range in Brazil to check the possibility of the existence of two distinct subspecies using also a reciprocal monophyly criterion. We analyzed the control region, and the Cytochrome b and Cytochrome c Oxidase subunit I genes of the mitochondrial DNA in several giant otter populations from the Amazon and Paraguai River Basins. Analyses have indicated some degree of geographic correlation and a high level of inter-population divergence, although the subspecies division is not highly supported. As we observed strong population structure, we cannot rule out the existence of further divisions shaping the species distribution. The results suggest that a more complex population structure occurs in P. brasiliensis, and the conservation practice should concentrate on preserving all remaining local populations. PMID:18278348

Garcia, D M; Marmontel, M; Rosas, F W; Santos, F R

2007-12-01

108

A Novel Anelloviridae Species Detected in Tadarida brasiliensis Bats: First Sequence of a Chiropteran Anellovirus  

PubMed Central

Using metagenomic approaches, we identified a novel Torque teno virus from Brazilian free-tailed bats (Tadarida brasiliensis) (TT-TbV). The TT-TbV genome and deduced protein sequences share extremely low identity with known anelloviruses. Due to a high degree of phylogenetic divergence, such putative virus could not be allocated into any Anelloviridae genera. PMID:25359906

Cibulski, Samuel Paulo; Teixeira, Thais Fumaco; de Sales Lima, Francisco Esmaile; do Santos, Helton Fernandes; Franco, Ana Claudia

2014-01-01

109

Neofusicoccum ribis Associated with Leaf Blight on Rubber (Hevea brasiliensis) in Peninsular Malaysia.  

PubMed

Hevea brasiliensis is a natural source of rubber and an important plantation tree species in Malaysia. Leaf blight disease caused by Fusicoccum substantially reduces the growth and performance of H. brasiliensis. The aim of this study was to use a combination of both morphological characteristics and molecular data to clarify the taxonomic position of the fungus associated with leaf blight disease. Fusicoccum species were isolated from infected leaves collected from plantations at 3 widely separated locations - Selangor, Perak, and Johor states - in Peninsular Malaysia in 2010. All the isolates were identified according to their conidial patterns and DNA sequences generated from internal transcribed spacers (ITS1 and ITS2), the 5.8S rRNA, and an unknown locus (BotF15) containing microsatellite repeats. Based on taxonomic and sequence data, Neofusicoccum ribis was identified as the main cause of leaf blight disease in H. brasiliensis in commercial plantations in Malaysia. A pathogenicity trial on detached leaves further confirmed that N. ribis causes leaf blight disease. N. ribis is an important leaf pathogen, and its detection in Malaysia has important implications for future planting of H. brasiliensis. PMID:25288924

Nyaka Ngobisa, A I C; Zainal Abidin, M A; Wong, M Y; Wan Noordin, M W D

2013-03-01

110

Characterisation of HEVER, a novel stress-induced gene from Hevea brasiliensis  

Microsoft Academic Search

A novel stress-induced gene, HEVER (Hevea ethylene-responsive) from the rubber tree, Hevea brasiliensis, has been isolated and characterised. HEVER is encoded by a multigene family. The HEVER transcript is expressed at basal levels in Hevea tissues and is developmentally regulated. In addition, the HEVER transcript and protein are induced by stress treatment with salicylic acid and ethephon. Sequence analysis shows

Shanthi Sivasubramaniam; Vasanthi M. Vanniasingham; Chio-Tee Tan; Nam-Hai Chua

1995-01-01

111

Feeding convergence in South American and African zooplanktivorous cichlids Geophagus brasiliensis and Tilapia rendalli  

Microsoft Academic Search

Acará, Geophagus brasiliensis, and red-breasted bream, Tilapia rendalli, are important planktivorous cichlids in southern Brazilian lakes and reservoirs. In laboratory experiments, I quantified behavior and selectivity of different sizes of these two fish feeding on lake zooplankton. Feeding behavior depended on fish size. Fish 70 mm were pump-filter feeders. Replicate 1 h feeding trials revealed that, as the relative proportions

Xavier Lazzaro

1991-01-01

112

High Altitude Flights of the Free-Tailed Bat, 'Tadarida brasiliensis', Observed with Radar.  

National Technical Information Service (NTIS)

Both search and height finding radars were used to observe the airborne behavior of Mexican Free-tailed bats, Tadarida brasiliensis mexicana, near several caves in the southwestern United States. Radar echoes from dense groups of bats covered areas as lar...

T. C. Williams, L. C. Ireland, J. M. Williams

1973-01-01

113

Feeding behavior and kinematics of the lesser electric ray, Narcine brasiliensis (Elasmobranchii: Batoidea)  

Microsoft Academic Search

Jaw protrusion is a major functional motif in fish feeding and can occur during mouth opening or closing. This temporal variation impacts the role that jaw protrusion plays in prey apprehension and processing. The lesser electric ray Narcine brasiliensis is a benthic elasmobranch (Batoidea: Torpediniformes) with an extreme and unique method of prey capture. The feeding kinematics of this species

Mason N. Dean; Philip J. Motta

2004-01-01

114

IL-4R?-Associated Antigen Processing by B Cells Promotes Immunity in Nippostrongylus brasiliensis Infection  

PubMed Central

In this study, B cell function in protective TH2 immunity against N. brasiliensis infection was investigated. Protection against secondary infection depended on IL-4R? and IL-13; but not IL-4. Protection did not associate with parasite specific antibody responses. Re-infection of B cell-specific IL-4R??/? mice resulted in increased worm burdens compared to control mice, despite their equivalent capacity to control primary infection. Impaired protection correlated with reduced lymphocyte IL-13 production and B cell MHC class II and CD86 surface expression. Adoptive transfer of in vivo N. brasiliensis primed IL-4R? expressing B cells into naïve BALB/c mice, but not IL-4R? or IL-13 deficient B cells, conferred protection against primary N. brasiliensis infection. This protection required MHC class II compatibility on B cells suggesting cognate interactions by B cells with CD4+ T cells were important to co-ordinate immunity. Furthermore, the rapid nature of these protective effects by B cells suggested non-BCR mediated mechanisms, such as via Toll Like Receptors, was involved, and this was supported by transfer experiments using antigen pulsed Myd88?/? B cells. These data suggest TLR dependent antigen processing by IL-4R?-responsive B cells producing IL-13 contribute significantly to CD4+ T cell-mediated protective immunity against N. brasiliensis infection. PMID:24204255

Hoving, Jennifer C.; Nieuwenhuizen, Natalie; McSorley, Henry J.; Ndlovu, Hlumani; Bobat, Saeeda; Kimberg, Matti; Kirstein, Frank; Cutler, Anthony J.; DeWals, Benjamin; Cunningham, Adam F.; Brombacher, Frank

2013-01-01

115

Neofusicoccum ribis Associated with Leaf Blight on Rubber (Hevea brasiliensis) in Peninsular Malaysia  

PubMed Central

Hevea brasiliensis is a natural source of rubber and an important plantation tree species in Malaysia. Leaf blight disease caused by Fusicoccum substantially reduces the growth and performance of H. brasiliensis. The aim of this study was to use a combination of both morphological characteristics and molecular data to clarify the taxonomic position of the fungus associated with leaf blight disease. Fusicoccum species were isolated from infected leaves collected from plantations at 3 widely separated locations – Selangor, Perak, and Johor states – in Peninsular Malaysia in 2010. All the isolates were identified according to their conidial patterns and DNA sequences generated from internal transcribed spacers (ITS1 and ITS2), the 5.8S rRNA, and an unknown locus (BotF15) containing microsatellite repeats. Based on taxonomic and sequence data, Neofusicoccum ribis was identified as the main cause of leaf blight disease in H. brasiliensis in commercial plantations in Malaysia. A pathogenicity trial on detached leaves further confirmed that N. ribis causes leaf blight disease. N. ribis is an important leaf pathogen, and its detection in Malaysia has important implications for future planting of H. brasiliensis.

Nyaka Ngobisa, A. I. C.; Zainal Abidin, M. A.; Wong, M. Y.; Wan Noordin, M. W. D.

2013-01-01

116

Pulmonary cavitation and skin lesions mimicking tuberculosis in a HIV negative patient caused by Sporothrix brasiliensis  

PubMed Central

A 32-year-old HIV negative male presented with multiple pulmonary cavitation and skin abscesses up to 15 cm in diameter mimicking tuberculosis. Sporothrix brasiliensis was isolated and patient responded well to amphotericin B followed by itraconazole, except the skin lesions that had to be surgical drained to obtain cure. PMID:24432220

Orofino-Costa, Rosane; Unterstell, Natasha; Carlos Gripp, Alexandre; de Macedo, Priscila Marques; Brota, Arles; Dias, Emylli; de Melo Teixeira, Marcus; Felipe, Maria Sueli; Bernardes-Engemann, Andrea R; Lopes-Bezerra, Leila Maria

2013-01-01

117

Stability of the hydroxynitrile lyase from Hevea brasiliensis: a fluorescence and dynamic light scattering study  

Microsoft Academic Search

The reasons for the deactivation of the hydroxynitrile lyase (Hnl) from the rubber tree (Hevea brasiliensis) at low pH values (below 4.0), and the influence of buffer salts as well as the possible stabilization of the enzyme by additives were investigated. For the elucidation of responsible phenomena, dynamic light scattering and fluorescence spectroscopy were employed. It was found that the

Andrea Hickel; Marion Graupner; Dieter Lehner; Albin Hermetter; Otto Glatter; Herfried Griengl

1997-01-01

118

Stability of the enzyme ( S)-hydroxynitrile lyase from Hevea brasiliensis  

Microsoft Academic Search

Inactivation of the enzyme (S)-hydroxynitrile lyase from Hevea brasiliensis (rubber tree) was studied using three different buffers: sodium glutamate, sodium phosphate and sodium citrate. Inactivation follows a first order kinetics and was expressed by the half-life of the enzyme. From the inactivation at different temperatures, the inactivation energy was calculated for the different buffer systems; no significant difference could be

Michael Bauer; Roland Geyer; Matthias Boy; Herfried Griengl; Walter Steiner

1998-01-01

119

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.

120

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

1994-01-01

121

Changes in kinematics and aerodynamics over a range of speeds in Tadarida brasiliensis, the Brazilian free-tailed bat  

PubMed Central

To date, wake measurements using particle image velocimetry (PIV) of bats in flight have studied only three bat species, all fruit and nectar feeders. In this study, we present the first wake structure analysis for an insectivorous bat. Tadarida brasiliensis, the Brazilian free-tailed bat, is an aerial hunter that annually migrates long distances and also differs strikingly from the previously investigated species morphologically. We compare the aerodynamics of T. brasiliensis with those of other, frugivorous bats and with common swifts, Apus apus, a bird with wing morphology, kinematics and flight ecology similar to that of these bats. The comparison reveals that, for the range of speeds evaluated, the cyclical pattern of aerodynamic forces associated with a wingbeat shows more similarities between T. brasiliensis and A. apus than between T. brasiliensis and other frugivorous bats. PMID:22258554

Hubel, Tatjana Y.; Hristov, Nickolay I.; Swartz, Sharon M.; Breuer, Kenneth S.

2012-01-01

122

Changes in kinematics and aerodynamics over a range of speeds in Tadarida brasiliensis, the Brazilian free-tailed bat.  

PubMed

To date, wake measurements using particle image velocimetry (PIV) of bats in flight have studied only three bat species, all fruit and nectar feeders. In this study, we present the first wake structure analysis for an insectivorous bat. Tadarida brasiliensis, the Brazilian free-tailed bat, is an aerial hunter that annually migrates long distances and also differs strikingly from the previously investigated species morphologically. We compare the aerodynamics of T. brasiliensis with those of other, frugivorous bats and with common swifts, Apus apus, a bird with wing morphology, kinematics and flight ecology similar to that of these bats. The comparison reveals that, for the range of speeds evaluated, the cyclical pattern of aerodynamic forces associated with a wingbeat shows more similarities between T. brasiliensis and A. apus than between T. brasiliensis and other frugivorous bats. PMID:22258554

Hubel, Tatjana Y; Hristov, Nickolay I; Swartz, Sharon M; Breuer, Kenneth S

2012-06-01

123

IL13, IL4R?, and Stat6 Are Required for the Expulsion of the Gastrointestinal Nematode Parasite Nippostrongylus brasiliensis  

Microsoft Academic Search

Although IL-4 induces expulsion of the gastrointestinal nematode parasite, Nippostrongylus brasiliensis, from immunodeficient mice, this parasite is expelled normally by IL-4-deficient mice. This apparent paradox is explained by observations that IL-4 receptor ? chain (IL-4R?)-deficient mice and Stat6-deficient mice fail to expel N. brasiliensis, and a specific antagonist for IL-13, another activator of Stat6 through IL-4R?, prevents worm expulsion. Thus,

Joseph F Urban Jr.; Nancy Noben-Trauth; Debra D Donaldson; Kathleen B Madden; Suzanne C Morris; Mary Collins; Fred D Finkelman

1998-01-01

124

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

1982-01-01

125

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...

2014-04-01

126

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

1995-01-01

127

Anti-proliferation effect of Hevea brasiliensis latex B-serum on human breast epithelial cells.  

PubMed

The rubber tree (Hevea brasiliensis) extracts are becoming increasingly visible in pharmaceutical and therapeutical research. The present study is aimed at examining the specific anti-proliferation property of H. brasiliensis latex B-serum sub-fractions against human breast cancer epithelial cell lines MCF-7 and MDA-MB231. The results showed that the latex whole B-serum and DBP sub-fraction exerted a specific anti-proliferation activity against cancer-origin cells MDA-MB231 but had little effect on non-cancer-origin cells. On the other hand, the anti-proliferative activity was diminished in the pre-heated B-serum fractions. With the low toxicity that the B-serum demonstrated previously in Brine Shrimp Lethality Test (BSLT), the present results suggest the potential use of the B-serum sub-fractions in cancer treatment. PMID:22713955

Lee, Yang Kok; Lay, Lam Kit; Mahsufi, Mansor Sharif; Guan, Teoh Siang; Elumalai, Sunderasan; Thong, Ong Ming

2012-07-01

128

Disseminated Sporothrix brasiliensis Infection with Endocardial and Ocular Involvement in an HIV-Infected Patient  

PubMed Central

Disseminated sporotrichosis occurs in individuals with impaired cellular immunity, such as in cases of neoplasia, transplantation, diabetes, and especially, acquired immunodeficiency syndrome. This report presents a 32-year-old Brazilian human immunodeficiency virus (HIV)-infected patient who developed a protracted condition of disseminated sporotrichosis with endocarditis, bilateral endophthalmitis, and lymphatic involvement. He needed cardiac surgery to replace the mitral valve. Sporothrix brasiliensis isolates were recovered from cultures of subcutaneous nodules and mitral valve fragments. Species identification was based on classical and molecular methods. The patient received amphotericin B for 52 days and subsequently, oral itraconazole. He remains asymptomatic, and he is on maintenance therapy with itraconazole. Despite his positive clinical outcome, he developed bilateral blindness. To our knowledge, this case is the first report of endocarditis and endophthalmitis caused by S. brasiliensis. PMID:22403321

Silva-Vergara, Mario Leon; de Camargo, Zoilo Pires; Silva, Patricia Ferreira; Abdalla, Michel Reis; Sgarbieri, Ricardo Nilsson; Rodrigues, Anderson Messias; dos Santos, Keila Cristina; Barata, Cristina Hueb; Ferreira-Paim, Kennio

2012-01-01

129

Performance and meat quality of broiler chickens that are fed diets supplemented with Agaricus brasiliensis mushrooms.  

PubMed

This trial was performed to study the use of the mushroom Agaricus brasiliensis as an alternative additive to antimicrobial growth promoters in broiler chicken diets and to assess the quality of the broiler chicken breast meat of birds that are fed diets containing this fungus. Thus, 595 1-day-old chicks were reared in reused poultry litter without anticoccidial and antimicrobial additives. The results showed that a concentration of 1.6 g mushrooms/kg diet was ideal for these birds because it provided better bird performance. When the birds' immune system organs were analyzed, it was found that the addition of both mushrooms influenced the immune system organs of these broiler chickens. Adding A. brasiliensis to broiler chicken diets did not compromise breast meat quality. PMID:25169695

Guimarães, João Borges; Dos Santos, Eder Clementino; Dias, Eustáquio Souza; Bertechini, Antônio Gilberto; da Silva Ávila, Carla Luiza; Dias, Francesca Silva

2014-12-01

130

Nitrogen-fixing bacterium Burkholderia brasiliensis produces a novel yersiniose A-containing O-polysaccharide.  

PubMed

Burkholderia brasiliensis, a Gram-negative diazotrophic endophytic bacterium, was first isolated from roots, stems, and leaves of rice plant in Brazil. The polysaccharide moiety was released by ammonolysis from the B. brasiliensis lipopolysaccharide (LPS), allowing the unambiguous characterization of a 3,6-dideoxy-4-C-(1-hydroxyethyl)-D-xylo-hexose (yersiniose A), an uncommon feature for Burkholderia LPS. The complete structure of the yersiniose A-containing O-antigen was identified by sugar and methylation analyses and NMR spectroscopy. Our results show that the repeating oligosaccharide motif of LPS O-chain consists of a branched tetrasaccharide with the following structure:-->2-alpha-d-Rhap-(1-->3)-[alpha-YerAp-(1-->2)]-alpha-D-Rhap-(1-->3)-alpha-D-Rhap-(1-->. PMID:15509723

Mattos, Katherine A; Todeschini, Adriane R; Heise, Norton; Jones, Christopher; Previato, Jose O; Mendonça-Previato, Lucia

2005-03-01

131

Antifungal activity of drimane sesquiterpenes from Drimys brasiliensis using bioassay-guided fractionation  

Microsoft Academic Search

Purpose. This study describes the antifungal effect of extracts and compounds isolated from Drimys brasiliensis acting against dermatophytes. Methods. The activities were evaluated by using the microbroth dilution method. Results. Bioassay-guided fractionation of the most active extract from the bark (CHCl3) led to the isolation of the sesquiterpene drimanes polygodial, 1- ?-(p-methoxycinnamoyl)-polygodial, drimanial and 1-?-(p-cumaroyloxy)-polygodial, which were selectively active against

Angela Malheiros; Valdir Cechinel Filho; Clarisse B. Schmitt; Rosendo A. Yunes; Andrea Escalante; Laura Svetaz

132

Cloning and characterization of a novel cysteine protease gene ( HbCP1 ) from Hevea brasiliensis  

Microsoft Academic Search

The full-length cDNA encoding a cysteine protease, designated HbCP1, was isolated for the first time from Hevea brasiliensis by the rapid amplification of cDNA ends (RACE) method. HbCP1 contained a 1371 bp open reading frame encoding 457 amino acids. The deduced HbCP1 protein, which showed high identity to\\u000a cysteine proteases of other plant species, was predicted to possess a putative

Shi-Qing Peng; Jia-Hong Zhu; Hui-Liang Li; Wei-Min Tian

2008-01-01

133

Effects of carbohydrate addition on the induction of somatic embryogenesis in Hevea brasiliensis  

Microsoft Academic Search

The effect of different carbohydrates was tested on early somatic embryogenesis of Hevea brasiliensis. Sucrose was replaced with maltose, fructose or glucose. Somatic embryo production was significantly higher with maltose.\\u000a With maltose, the initial yellow colour of the calli turned orange, and dry matter production after 28 days' culture was half\\u000a that obtained with sucrose. Maltose also reduced the soluble

G. Blanc; N. Michaux-Ferrière; C. Teisson; L. Lardet; M. P. Carron

1999-01-01

134

Cross-species characterisation of polymorphic microsatellite loci in the giant otter (Pteronura brasiliensis).  

PubMed

Nineteen microsatellite loci developed for the Eurasian otter (Lutra lutra) and 15 loci developed for the North American river otter (Lontra canadensis) were tested for ease of amplification and degree of polymorphism on a set of 20 giant otter (Pteronura brasiliensis) faecal samples from the Bolivian Amazon basin. Nineteen loci amplified consistently well, with polymorphisms ranging from two to nine alleles and observed heterozygosity ranging from 0.15 to 0.85. PMID:21564666

Pickles, Robert S A; Groombridge, James J; Rojas, Veronica D Zambrana; Jordan, William C

2009-01-01

135

Cloning and expression of the gene encoding solanesyl diphosphate synthase from Hevea brasiliensis  

Microsoft Academic Search

Summary Plastoquinones play important roles as electron carriers in the light-dependent reactions of photosynthesis and also as a cofactor of phytoene desaturation in the synthesis of carotenoid. A plastoquinone-9 (PQ-9) was identified in Frey-Wyssling organelles of fresh rubber latex from Hevea brasiliensis. This indicates that a Hevea solanesyl diphosphate synthase (HbSDS) must be present for the synthesis of the C45

Atiphon Phatthiya; Seiji Takahashi; Nopphakaew Chareonthiphakorn; Tanetoshi Koyama; Dhirayos Wititsuwannakul; Rapepun Wititsuwannakul

2007-01-01

136

Structural determinants of the enantioselectivity of the hydroxynitrile lyase from Hevea brasiliensis  

Microsoft Academic Search

The hydroxynitrile lyase from the tropical rubber tree Hevea brasiliensis (HbHNL) is utilized as a biocatalyst in stereospecific syntheses of ?-hydroxynitriles from aldehydes and methyl-ketones. The catalyzed reaction represents one of the few industrially relevant examples of enzyme mediated C–C coupling reactions. In this work, we determined the X-ray crystal structures (at 1.54 and 1.76Å resolution) of HbHNL complexes with

Günter Gartler; Christoph Kratky; Karl Gruber

2007-01-01

137

Study of the ( S)-hydroxynitrile lyase from Hevea brasiliensis: mechanistic implications  

Microsoft Academic Search

Investigations of the (S)-selective hydroxynitrile lyase from Hevea brasiliensis were performed by electrospray mass spectroscopy, 1H-NMR and with an enzyme activity assay. For the trans-cyanohydrin reaction (transcyanation) a two step reaction could be established. The results furthermore indicate a fast deactivation of the enzyme at low pH and a strong substrate dependence of its stability. They rule out an enzyme-HCN

Ulf Hanefeld; Adrie J. J. Straathof; Joseph J. Heijnen

1999-01-01

138

Preparation of optically active cyanohydrins using the ( S)-hydroxynitrile lyase from Hevea brasiliensis  

Microsoft Academic Search

Several aliphatic, aromatic and heteroaromatic aldehydes have been converted into the chiral cyanohydrins using the (S)-hydroxynitrile lyase from Hevea brasiliensis. The corresponding cyanohydrins were obtained in moderate to good yield and high enantiomeric excess with the exeption of phenyloxyacetaldehyde, benzyloxyacetaldehyde and the pyrrole-, pyridine- and indolealdehydes investigated. In contrast to previously reported results, cinnamaldehyde could be converted into (S)-(?)-2-hydroxy-4-phenyl-(E)-but-3-enenitrile with

Michael Schmidt; Stephanie Hervé; Norbert Klempier; Herfried Griengl

1996-01-01

139

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

PubMed

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

2014-10-01

140

Bark Harvesting Systems of Drimys brasiliensis Miers in the Brazilian Atlantic Rainforest.  

PubMed

Drimys brasiliensis Miers, locally known as cataia or casca-de-anta, is a native tree species of the Atlantic Rainforest. Its bark is harvested from natural populations. This study examined the recovery capacity of the bark of D. brasiliensis under different bark harvesting methods, as well as the influence of these approaches on its population dynamics and reproductive biology. While none of these treatments resulted in changes in phenological behavior or the rate of increase of diameter at breast height and tree height, the removal of wider bark strips resulted in lower rates of bark recovery and higher rates of insect attack and diseases. Accordingly, the results recommend using strips of bark 2 cm wide and 2 m long, with 4 cm between strips, for effective rates of bark regrowth and for lower susceptibility to insect attack and diseases. From these studies, we concluded that D. brasiliensis has a high potential for sustainable management of its natural populations, demonstrating the possibility of generating an important supplementary income for farmers and contributing to the use and conservation of the Atlantic Rainforest. PMID:25119732

Mariot, Alexandre; Mantovani, Adelar; Reis, Maurício S Dos

2014-09-01

141

The sialotranscriptome of the blood-sucking bug Triatoma brasiliensis (Hemiptera, Triatominae)  

PubMed Central

Triatoma brasiliensis is the most important autochthon vector of Trypanosoma cruzi in Brazil, where it is widely distributed in the semiarid areas of the Northeast. In order to advance the knowledge of the salivary biomolecules of Triatominae, a salivary gland cDNA library of T. brasiliensis was mass sequenced and analyzed. Polypeptides were sequenced by HPLC/Edman degradation experiments. 1,712 cDNA sequences were obtained and grouped in 786 clusters. The housekeeping category had 24.4% and 17.8% of the clusters and sequences, respectively. The putatively secreted category contained 47.1% of the clusters and 68.2% of the sequences. Finally, 28.5% of the clusters, containing 14% of all sequences, were classified as unknown. The sialoma of T. brasiliensis showed a high amount and great variety of different lipocalins (93.8% of secreted proteins). Remarkably, a great number of serine proteases that were not observed in previous blood-sucking sialotranscriptomes were found. Nine Kazal peptides were identified, among them one with high homology to the tabanid vasodilator vasotab, suggesting that the Triatoma vasodilator could be a Kazal protein. PMID:17550826

Santos, Adriana; Ribeiro, Jose Marcos C.; Lehane, Michael J.; Gontijo, Nelder Figueiredo; Veloso, Artur Botelho; Sant'Anna, Mauricio R.V.; Araujo, Ricardo Nascimento; Grisard, Edmundo C.; Pereira, Marcos Horacio

2007-01-01

142

Nocardia brasiliensis Induces Formation of Foamy Macrophages and Dendritic Cells In Vitro and In Vivo  

PubMed Central

Foamy cells have been described in various infectious diseases, for example in actinomycetoma induced by Nocardia brasiliensis. These cells are generally considered to be macrophages, although they present dendritic cell (DC)-specific surface markers. In this study, we determined and confirmed the lineage of possible precursors of foamy cells in vitro and in vivo using an experimental actinomycetoma model in BALB/c mice. Bone marrow-derived macrophages (BMDM) or DC (BMDC) were infected in vitro with N. brasiliensis or labeled with carboxyfluorescein diacetate succinimidyl ester (CFSE). Both, macrophages and DC, differentiated into foamy cells after in vitro infection. CFSE-labeled BMDM or BMDC were tested for phagocytosis and CD11c/CD11b receptors markers expression before being transferred into the actinomycetoma lesion site of infected mice. In vivo studies showed that BMDM and BMDC were traced at the site where foamy cells are present in the experimental actinomycetoma. Interestingly, many of the transferred BMDM and BMDC were stained with the lipid-droplet fluorophore Nile Red. In conclusion, macrophages and DC cells can be differentiated into foamy cells in vitro and in vivo during N. brasiliensis infection. PMID:24936860

Meester, Irene; Rosas-Taraco, Adrian Geovanni; Salinas-Carmona, Mario Cesar

2014-01-01

143

Yeast ecology of Kombucha fermentation.  

PubMed

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

2004-09-01

144

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.

145

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.

2012-01-01

146

Yeast models for amyloid disease.  

PubMed

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

2014-01-01

147

Yeasts preservation: alternatives for lyophilisation.  

PubMed

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

2012-11-01

148

Pulmonary infection in two sympatric lizards, Mabuya arajara (Scincidae) and Anolis brasiliensis (Polychrotidae) from a cloud forest in Chapada do Araripe, Ceará, Northeastern Brazil.  

PubMed

The parameters of infection by lung parasites from two sympatric lizards, Mabuya arajara and Anolis brasiliensis, from the Atlantic Rainforest of the lower slope of Chapada do Araripe in Northeastern Brazil were analyzed between September, 2009 and July, 2010. A total of 202 lizards were collected. 125 specimens were from Mabuya arajara and 77 from Anolis brasiliensis. M. arajara was infected by the pentastomid Raillietiella mottae while A. brasiliensis was infected by the nematode Rhabdias sp., with an overall prevalence of 1.6% and 28.6%, respectively. The mean intensity of infection by Rhabdias sp. was 3.63 ± 2.58 (range 1-15). The body size and sex of lizards did not influence the intensity of infection by Rhabdias sp. The overall prevalence was also not different between males and females hosts in A. brasiliensis. Both Anolis brasiliensis and Mabuya arajara represent a new host to Rhabdias sp. and Raillietiella mottae, respectively. PMID:23295524

Ribeiro, S C; Ferreira, F S; Brito, S V; Teles, D A; Ávila, R W; Almeida, W O; Anjos, L A; Guarnieri, M C

2012-11-01

149

Microsatellite marker development for the rubber tree (Hevea brasiliensis): characterization and cross-amplification in wild Hevea species  

PubMed Central

Background The rubber tree (Hevea brasiliensis) is native to the Amazon region and it is the major source of natural rubber in the world. Rubber tree breeding is time-consuming and expensive. However, molecular markers such as microsatellites can reduce the time required for these programs. This study reports new genomic microsatellite markers developed and characterized in H. brasiliensis and the evaluation of their transferability to other Hevea species. Findings We constructed di- and trinucleotide-enriched libraries. From these two libraries, 153 primer pairs were designed and initially evaluated using 9 genotypes of H. brasiliensis. A total of 119 primer pairs had a good amplification product, 90 of which were polymorphic. We chose 46 of the polymorphic markers and characterized them in 36 genotypes of H. brasiliensis. The expected and observed heterozygosities ranged from 0.1387 to 0.8629 and 0.0909 to 0.9167, respectively. The polymorphism information content (PIC) values ranged from 0.097 to 0.8339, and the mean number of alleles was 6.4 (2–17). These 46 microsatellites were also tested in 6 other Hevea species. The percentage of transferability ranged from 82% to 87%. Locus duplication was found in H. brasiliensis and also in 5 of other species in which transferability was tested. Conclusions This study reports new microsatellite markers for H. brasiliensis that can be used for genetic linkage mapping, quantitative trait loci identification and marker- assisted selection. The high percentage of transferability may be useful in the evaluations of genetic variability and to monitor introgression of genetic variability from different Hevea species into breeding programs. PMID:22731927

2012-01-01

150

Experimentally induced tick toxicosis in rats bitten by Ornithodoros brasiliensis (Chelicerata: Argasidae): a clinico-pathological characterization.  

PubMed

Ornithodoros brasiliensis, also known as the mouro tick, is an argasid tick only found in the highlands of Southern Brazil. O. brasiliensis parasitism is associated with severe reactions in its hosts ranging from local pruritus and pain to systemic disturbances. Recently, the re-emergence of O. brasiliensis parasitism in humans and dogs drew attention to the clinical findings induced by its bite, which are poorly understood and described. Moreover, rare experimental data about tick bite effects under controlled conditions were available. Thus, this study aimed to describe clinical and pathological findings induced by O. brasiliensis bites in experimentally parasitized rats. Ticks feed for ?40 min in rats, and their weight increased by approximately four times after the blood meal. Rats bitten by five adult ticks showed hyperemia of the oral/ocular mucosa, piloerection, tachypnea, claudication, ocular and nasal discharge, pruritus, and swollen and erythemic lesions. A large hemorrhagic lesion was observed on rat skin in tick attachment sites, reaching ?17 mm in diameter 12 h after a bite. Bitten rats also presented an increased bleeding tendency (?50%) 6 h after a tick bite, evaluated by the tail-cut rat model of bleeding. Blood samples of bitten rats were taken, and clinical pathology analysis showed significant alterations in the eosinophil and basophil counts, in creatine phosphokinase (CPK) and CPK MB fraction, and lactate dehydrogenase (LDH) activity, and fibrinogen level. Histopathological analysis revealed marked subcutaneous hemorrhage, edema and slight muscle degeneration at the bite site. Also, muscle degeneration and necrosis were observed in the myocardium of bitten rats 72 h after bites by histopathology and immunohistochemistry against troponin C. This work showed the ability of O. brasiliensis to cause severe disturbances in experimentally parasitized rats, compatible with a tick toxicosis syndrome. This observation associated with the re-emergence of O. brasiliensis parasitism makes this parasite as a public health hazard in southern Brazil. PMID:24973739

Reck, José; Bandarra, Paulo; Pavarini, Saulo; Termignoni, Carlos; Driemeier, David; Martins, João Ricardo; Guimarães, Jorge A

2014-09-01

151

Characterisation of HEVER, a novel stress-induced gene from Hevea brasiliensis.  

PubMed

A novel stress-induced gene, HEVER (Hevea ethylene-responsive) from the rubber tree, Hevea brasiliensis, has been isolated and characterised. HEVER is encoded by a multigene family. The HEVER transcript is expressed at basal levels in Hevea tissues and is developmentally regulated. In addition, the HEVER transcript and protein are induced by stress treatment with salicylic acid and ethephon. Sequence analysis shows that HEVER encodes a 33 kDa protein that has significant homology to the hypothetical protein SLEXORFA-1 from the plant, Stellaria longipes, and two bacterial proteins, BAC180K-75 from Bacillus subtilis and MVRNO3-1 from Methanococcus vannielii. PMID:7579163

Sivasubramaniam, S; Vanniasingham, V M; Tan, C T; Chua, N H

1995-10-01

152

Study of the (S)-hydroxynitrile lyase from Hevea brasiliensis: mechanistic implications.  

PubMed

Investigations of the (S)-selective hydroxynitrile lyase from Hevea brasiliensis were performed by electrospray mass spectroscopy, (1)H-NMR and with an enzyme activity assay. For the trans-cyanohydrin reaction (transcyanation) a two step reaction could be established. The results furthermore indicate a fast deactivation of the enzyme at low pH and a strong substrate dependence of its stability. They rule out an enzyme-HCN complex or a covalently bound carbonyl compound. Therefore the earlier postulated reaction intermediate as well as the proposed action of the catalytic triad have to be reevaluated. The calculated molecular mass could be confirmed by mass spectroscopy. PMID:10407140

Hanefeld, U; Straathof, A J; Heijnen, J J

1999-07-13

153

Nuclear transport of yeast proteasomes.  

PubMed

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

2014-01-01

154

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)

2012-12-04

155

The yeasts of cheese brines.  

PubMed

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

1990-12-01

156

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

157

APPENDIX 4LGrowth and Manipulation of Yeast PREPARATION OF SELECTED YEAST MEDIA  

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

158

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.

159

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.

2000-01-01

160

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

2012-01-01

161

Sequence and Expression Analyses of Ethylene Response Factors Highly Expressed in Latex Cells from Hevea brasiliensis  

PubMed Central

The AP2/ERF superfamily encodes transcription factors that play a key role in plant development and responses to abiotic and biotic stress. In Hevea brasiliensis, ERF genes have been identified by RNA sequencing. This study set out to validate the number of HbERF genes, and identify ERF genes involved in the regulation of latex cell metabolism. A comprehensive Hevea transcriptome was improved using additional RNA reads from reproductive tissues. Newly assembled contigs were annotated in the Gene Ontology database and were assigned to 3 main categories. The AP2/ERF superfamily is the third most represented compared with other transcription factor families. A comparison with genomic scaffolds led to an estimation of 114 AP2/ERF genes and 1 soloist in Hevea brasiliensis. Based on a phylogenetic analysis, functions were predicted for 26 HbERF genes. A relative transcript abundance analysis was performed by real-time RT-PCR in various tissues. Transcripts of ERFs from group I and VIII were very abundant in all tissues while those of group VII were highly accumulated in latex cells. Seven of the thirty-five ERF expression marker genes were highly expressed in latex. Subcellular localization and transactivation analyses suggested that HbERF-VII candidate genes encoded functional transcription factors. PMID:24971876

Piyatrakul, Piyanuch; Yang, Meng; Putranto, Riza-Arief; Pirrello, Julien; Dessailly, Florence; Hu, Songnian; Summo, Marilyne; Theeravatanasuk, Kannikar; Leclercq, Julie; Kuswanhadi; Montoro, Pascal

2014-01-01

162

Systemic increased immune response to Nocardia brasiliensis co-exists with local immunosuppressive microenvironment.  

PubMed

Human diseases produced by pathogenic actinomycetes are increasing because they may be present as opportunistic infections. Some of these microbes cause systemic infections associated with immunosuppressive conditions, such as chemotherapy for cancer, immunosuppressive therapy for transplant, autoimmune conditions, and AIDS; while others usually cause localized infection in immunocompetent individuals. Other factors related to this increase in incidence are: antibiotic resistance, not well defined taxonomy, and a delay in isolation and identification of the offending microbe. Examples of these infections are systemic disease and brain abscesses produced by Nocardia asteroides or the located disease by Nocardia brasiliensis, named actinomycetoma. During the Pathogenic Actinomycetes Symposium of the 16th International Symposium on Biology of Actinomycetes (ISBA), held in Puerto Vallarta, Mexico, several authors presented recent research on the mechanisms by which N. brasiliensis modulates the immune system to survive in the host and advances in medical treatment of human actinomycetoma. Antibiotics and antimicrobials that are effective against severe actinomycetoma infections with an excellent therapeutic outcome and experimental studies of drugs that show promising bacterial inhibition in vivo and in vitro were presented. Here we demonstrate a systemic strong acquired immune response in humans and experimental mice at the same time of a local dominance of anti inflammatory cytokines environment. The pathogenic mechanisms of some actinomycetes include generation of an immunosuppressive micro environment to evade the protective immune response. This information will be helpful in understanding pathogenesis and to design new drugs for treatment of actinomycetoma. PMID:22825801

Salinas-Carmona, Mario Cesar; Rosas-Taraco, Adrian Geovanni; Welsh, Oliverio

2012-10-01

163

Statistical based media optimization and production of naringinase using Aspergillus brasiliensis 1344.  

PubMed

Statistics based optimization, Plackett-Burman design (PBD) and response surface methodology (RSM) were employed to screen and optimize the media components for the production of naringinase from Aspergillus brasiliensis MTCC 1344, using solid state fermentation. Cassava waste (CW) was used as both the solid support and carbon source for the growth of A. brasiliensis. Based on the positive influence of the Pareto chart obtained from PBD on naringinase activity, three media components--maltose, peptone and calcium chloride were screened. Box-Behnken design (BBD) was employed using these three factors at three levels, for further optimization, and the second order polynomial equation was derived, based on the experimental data. Derringer's desired function methodology showed that the concentrations of maltose (7.74 g/L), peptone (4.19 g/L) and calcium chloride (7.63 mM) were the optimal levels for maximal naringinase activity (889.91 U/mg) which were validated through experiments. PMID:24380816

Shanmugaprakash, M; Kirthika, J; Ragupathy, J; Nilanee, K; Manickam, A

2014-03-01

164

Trypanosoma cruzi infection modulates the expression of Triatoma brasiliensis def1 in the midgut.  

PubMed

Antimicrobial peptides are an essential component of the insect immune system. One of the most ubiquitous is defensin, which has been identified in all examined insect orders. Triatoma brasiliensis (Heteroptera, Triatominae), the main Trypanosoma cruzi vector in semi-arid regions of north-eastern Brazil, expresses def1, a defensin encoding gene, predominantly in the anterior region (cardia and stomach) of the midgut. In the present study, we compared the transcript abundance of T. brasiliensis def1 in the anterior (stomach) and posterior midgut (small intestine) regions of naïve bugs with those infected with a familiar T. cruzi isolate. In the stomach, only slight differences between the two insect groups were visible, whereas in the small intestine wide differences (up to 9.6-fold) between infected and noninfected bugs become apparent. The highly increased def1 transcript abundance at 20 days after the infective blood meal might be a response to the T. cruzi infection, suggesting a potential function of intestinal defensin in the parasite population control. PMID:20925526

Waniek, Peter J; Jansen, Ana M; Araújo, Catarina A C

2011-07-01

165

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

166

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

2003-01-01

167

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

2004-01-01

168

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

2005-01-01

169

Habitat use by Myotis yumanensis and Tadarida brasiliensis mexicana in South San Francisco Bay wetlands: An Acoustic Study  

Microsoft Academic Search

Research on bat habitat use within coastal estuaries is limited. The purposes of my study were to determine whether Yuma myotis (Myotis yumanensis) and Mexican free-tailed bats (Tadarida brasiliensis mexicana) differentiate between open water and marsh within saline and brackish habitats and to examine whether climatic factors are correlated with general activity and tidal height with foraging of the two

Theresa Brickley

2012-01-01

170

Consumption rate, food preferences and transit time of captive giant otters Pteronura brasiliensis: Implications for the study of wild populations  

Microsoft Academic Search

Food consumption, food preferences and transit time of digesta were determined in captive giant otters, Pteronura brasiliensis, at the National Institute of Amazon Research (INPA), Manaus, Brazil. Food consumption of an adult female was 0.0997 kg1 day1. Giant otters showed sig- nificant and varied preferences for the single Siluriformes (catfish) and various Characiformes species offered. The adult female preferred Anostomidae

Sarah K. Carter; Fernando C. W. Rosas; Andrew B. Cooper; A. C. Cordeiro-Duarte

171

Description of the female, pupa and gall of Pisphondylia brasiliensis Couri and Maia, 1992 (Diptera: Cecidomyiidae, Schizomyiina) with new records.  

PubMed

The gall of Pisphondylia brasiliensis on Guapira opposita, its female and pupa are described and illustrated. The geographic distribution of this species is now widened to Minas Gerais and Rio Grande do Sul (Brazil). For the first time, a female of the genus is described. PMID:21180914

Maia, V C; Fleury, G; Soares, G L G; Isaias, R M S

2010-11-01

172

Polyketide Synthase Gene Diversity within the Microbiome of the Sponge Arenosclera brasiliensis, Endemic to the Southern Atlantic Ocean  

PubMed Central

Microbes associated with marine sponges are considered important producers of bioactive, structurally unique polyketides. The synthesis of such secondary metabolites involves type I polyketide synthases (PKSs), which are enzymes that reach a maximum complexity degree in bacteria. The Haplosclerida sponge Arenosclera brasiliensis hosts a complex microbiota and is the source of arenosclerins, alkaloids with cytotoxic and antibacterial activity. In the present investigation, we performed high-throughput sequencing of the ketosynthase (KS) amplicon to investigate the diversity of PKS genes present in the metagenome of A. brasiliensis. Almost 4,000 ketosynthase reads were recovered, with about 90% annotated automatically as bacterial. A total of 235 bacterial KS contigs was rigorously assembled from this sequence pool and submitted to phylogenetic analysis. A great diversity of six type I PKS groups has been consistently detected in our phylogenetic reconstructions, including a novel and A. brasiliensis-exclusive group. Our study is the first to reveal the diversity of type I PKS genes in A. brasiliensis as well as the potential of its microbiome to serve as a source of new polyketides. PMID:23275501

Trindade-Silva, Amaro E.; Rua, Cintia P. J.; Andrade, Bruno G. N.; Vicente, Ana Carolina Paulo; Silva, Genivaldo G. Z.

2013-01-01

173

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

1957-01-01

174

Domestic, peridomestic and wild hosts in the transmission of Trypanosoma cruzi in the Caatinga area colonised by Triatoma brasiliensis.  

PubMed

The role played by different mammal species in the maintenance of Trypanosoma cruzi is not constant and varies in time and place. This study aimed to characterise the importance of domestic, wild and peridomestic hosts in the transmission of T. cruzi in Tauá, state of Ceará, Caatinga area, Brazil, with an emphasis on those environments colonised by Triatoma brasiliensis. Direct parasitological examinations were performed on insects and mammals, serologic tests were performed on household and outdoor mammals and multiplex polymerase chain reaction was used on wild mammals. Cytochrome b was used as a food source for wild insects. The serum prevalence in dogs was 38% (20/53), while in pigs it was 6% (2/34). The percentages of the most abundantly infected wild animals were as follows: Thrichomys laurentius 74% (83/112) and Kerodon rupestris 10% (11/112). Of the 749 triatomines collected in the household research, 49.3% (369/749) were positive for T. brasiliensis, while 6.8% were infected with T. cruzi (25/369). In captured animals, T. brasiliensis shares a natural environment with T. laurentius, K. rupestris, Didelphis albiventris, Monodelphis domestica, Galea spixii, Wiedomys pyrrhorhinos, Conepatus semistriatus and Mus musculus. In animals identified via their food source, T. brasiliensis shares a natural environment with G. spixii, K. rupestris, Capra hircus, Gallus gallus, Tropidurus oreadicus and Tupinambis merianae. The high prevalence of T. cruzi in household and peridomiciliar animals reinforces the narrow relationship between the enzootic cycle and humans in environments with T. brasiliensis and characterises it as ubiquitous. PMID:25410992

Bezerra, Claudia Mendonça; Cavalcanti, Luciano Pamplona de Góes; Souza, Rita de Cássia Moreira de; Barbosa, Silvia Ermelinda; Xavier, Samanta Cristina das Chagas; Jansen, Ana Maria; Ramalho, Relrison Dias; Diotaiut, Liléia

2014-11-01

175

Transcriptome Sequencing of Hevea brasiliensis for Development of Microsatellite Markers and Construction of a Genetic Linkage Map  

PubMed Central

To obtain more information on the Hevea brasiliensis genome, we sequenced the transcriptome from the vegetative shoot apex yielding 2 311 497 reads. Clustering and assembly of the reads produced a total of 113 313 unique sequences, comprising 28 387 isotigs and 84 926 singletons. Also, 17 819 expressed sequence tag (EST)-simple sequence repeats (SSRs) were identified from the data set. To demonstrate the use of this EST resource for marker development, primers were designed for 430 of the EST-SSRs. Three hundred and twenty-three primer pairs were amplifiable in H. brasiliensis clones. Polymorphic information content values of selected 47 SSRs among 20 H. brasiliensis clones ranged from 0.13 to 0.71, with an average of 0.51. A dendrogram of genetic similarities between the 20 H. brasiliensis clones using these 47 EST-SSRs suggested two distinct groups that correlated well with clone pedigree. These novel EST-SSRs together with the published SSRs were used for the construction of an integrated parental linkage map of H. brasiliensis based on 81 lines of an F1 mapping population. The map consisted of 97 loci, consisting of 37 novel EST-SSRs and 60 published SSRs, distributed on 23 linkage groups and covered 842.9 cM with a mean interval of 11.9 cM and ?4 loci per linkage group. Although the numbers of linkage groups exceed the haploid number (18), but with several common markers between homologous linkage groups with the previous map indicated that the F1 map in this study is appropriate for further study in marker-assisted selection. PMID:22086998

Triwitayakorn, Kanokporn; Chatkulkawin, Pornsupa; Kanjanawattanawong, Supanath; Sraphet, Supajit; Yoocha, Thippawan; Sangsrakru, Duangjai; Chanprasert, Juntima; Ngamphiw, Chumpol; Jomchai, Nukoon; Therawattanasuk, Kanikar; Tangphatsornruang, Sithichoke

2011-01-01

176

Genetically modified industrial yeast ready for application.  

PubMed

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

2002-01-01

177

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.

1981-01-01

178

Immunocytochemical detection of vasoactive intestinal peptide-like and peptide histidine isoleucine-like peptides in the nervous system and the excretory system of adult Nippostrongylus brasiliensis  

Microsoft Academic Search

Vasoactive intestinal peptide-like and peptide histidine isoleucine-like immunoreactivities were detected in the excretory duct of adult male and female Nippostrongylus brasiliensis, thus indicating the source of these two physiologically active peptides previously isolated from the excretory\\/secretory products of adult N. brasiliensis. In the nervous system immunoreactivity to both these peptides was confined to females and was found in the neurons

N Foster

1998-01-01

179

Structure and ultrastructure of leaf and calyx glands in Galphimia brasiliensis (Malpighiaceae).  

PubMed

The present study describes the anatomical structure of calyx and leaf glands in Galphimia brasiliensis and analyzes the mechanism of secretion. The glands are marginal and suprabasal, cup-shaped, sessile, and scarcely visible with the naked eye. Light microscopy reveals the following features: a thin, smooth cuticle; unistratified secretory cells; subglandular parenchyma; and vascular bundle supply composed of phloem and xylem with abundant druses of calcium oxalate. Transmission electron microscopy reveals the presence of secretory cells with conspicuous nuclei, dense cytoplasm, lipid droplets, numerous vesicles, mitochondria, Golgi, rough endoplasmic reticulum (RER), and elongated plastids with osmiophilic contents. The secretion reaches the apoplastic space and accumulates beneath the cuticle. Finally, the viscous, translucent exudate is eliminated by mechanical rupture of the cuticle. Histochemical analysis confirms that lipids are the main constituent. Small amounts of polysaccharides were also identified. PMID:21669626

Castro, M A; Vega, A S; Múlgura, M E

2001-11-01

180

Protective Effect of Agaricus brasiliensis on STZ-Induced Diabetic Neuropathic Pain in Rats  

PubMed Central

Objective. The present investigation examined the neuroprotective effect of Agaricus brasiliensis (AbS) against STZ-induced diabetic neuropathic pain in laboratory rats. STZ-induced diabetic rats were administered orally with AbS. Body weight, serum glucose, and behavioral parameters were measured before and at the end of the experiment to see the effect of AbS on these parameters. After 6 weeks of treatments, all animals were sacrificed to study various biochemical parameters. Treatment with AbS 80?mg/kg in diabetic animals showed significant increase in body weight, pain threshold, and paw withdrawal threshold and significant decrease in serum glucose, LPO and NO level, Na-K-ATPase level, and TNF-? and IL-1? level as compared to vehicle treated diabetic animals in dose and time dependent manner. AbS can offer pain relief in PDN. This may be of potential benefit in clinical practice for the management of diabetic neuropathy. PMID:24527050

Ji, Weifeng; Huang, Haiying; Chao, Ji; Lu, Wuchao; Guo, Jianyou

2014-01-01

181

Tourism values for Mexican free-tailed bat (Tadarida brasiliensis mexicana) viewing  

USGS Publications Warehouse

Migratory species provide diverse ecosystem services to people, but these values have seldom been estimated rangewide for a single species. In this article, we summarize visitation and consumer surplus for recreational visitors to viewing sites for the Mexican free-tailed bat (Tadarida brasiliensis mexicana) throughout the Southwestern United States. Public bat viewing opportunities are available at 17 of 25 major roosts across six states; on an annual basis, we estimate that over 242,000 visitors view bats, gaining over $6.5 million in consumer surplus. A better understanding of spatial mismatches between the areas where bats provide value to people and areas most critical for maintaining migratory populations can better inform conservation planning, including economic incentive systems for conservation.

Bagstad, Kenneth J.; Widerholdt, Ruscena

2013-01-01

182

Induction of micronuclei by alkaloids extracted from Senecio brasiliensis and stored for 23 years.  

PubMed

In the present study, we report the results of an investigation on pyrrolizidine alkaloids extracted from Senecio brasiliensis (Sprengel) Less., which were stored for more than 23 years under variable conditions of temperature and humidity and exposed to light. Both the crude alkaloid (integerrimine+retrorsine+impurities) and pure integerrimine conserved the ability to induce acute toxicity in mice, leading to the death of the animals in less than 24h. The alkaloids also conserved the potential to induce significant increases in micronucleus frequencies in polychromatic erythrocytes of mouse bone marrow compared to the negative control. The administration of alkaloids to lymphocyte cultures blocked with cytochalasin-B showed no significant increase in micronucleus frequency in binucleated cells, probably due to the lack of a metabolic activation mechanism. However, an antimitotic effect was observed. PMID:11943607

Santos-Mello, R; Deimlimg, L I; Lauer Júnior, C M; Almeida, A

2002-04-26

183

The primary structure of hevamine, an enzyme with lysozyme/chitinase activity from Hevea brasiliensis latex.  

PubMed

The primary structure of hevamine, an enzyme with lysozyme/chitinase activity from Hevea brasiliensis latex, has been determined predominantly with conventional non-automatic methods. The positions of three disulfide bridges have been determined. The sequence has about 60% identity with that of a chitinase from cucumber and 95% with the N-terminal sequence of the lysozyme/chitinase of Parthenocissus quinquefolia. The half-cystine residues in hevein and cucumber chitinase are located at identical positions. Hevamine is a basic protein from the lutoids (vacuoles) of rubber latex and may have a role in plugging the latex vessels and cessation of latex flow. The differences in cellular location, charge properties and sequence between hevamine and cucumber chitinase are similar to those between class I and class II chitinases from tobacco and other plant species. PMID:1879417

Jekel, P A; Hartmann, B H; Beintema, J J

1991-08-15

184

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

2009-01-01

185

Preparation of extracts from yeast.  

PubMed

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

2011-01-01

186

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

187

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

1998-01-01

188

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

1978-01-01

189

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

2013-01-01

190

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.

2009-01-01

191

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

2001-01-01

192

Roosting ecology and variation in adaptive and innate immune system function in the Brazilian free-tailed bat ( Tadarida brasiliensis )  

Microsoft Academic Search

Bats have recently been implicated as reservoirs of important emerging diseases. However, few studies have examined immune\\u000a responses in bats, and even fewer have evaluated these responses in an ecological context. We examined aspects of both innate\\u000a and adaptive immune response in adult female Brazilian free-tailed bats (Tadarida brasiliensis) at four maternity roosts (two natural caves and two human-made bridges)

Louise C. Allen; Amy S. Turmelle; Mary T. Mendonça; Kristen J. Navara; Thomas H. Kunz; Gary F. McCracken

2009-01-01

193

De novo transcriptome analysis of Hevea brasiliensis tissues by RNA-seq and screening for molecular markers  

PubMed Central

Background The rubber tree, Hevea brasiliensis, is a species native to the Brazilian Amazon region and it supplies almost all the world’s natural rubber, a strategic raw material for a variety of products. One of the major challenges for developing rubber tree plantations is adapting the plant to biotic and abiotic stress. Transcriptome analysis is one of the main approaches for identifying the complete set of active genes in a cell or tissue for a specific developmental stage or physiological condition. Results Here, we report on the sequencing, assembling, annotation and screening for molecular markers from a pool of H. brasiliensis tissues. A total of 17,166 contigs were successfully annotated. Then, 2,191 Single Nucleotide Variation (SNV) and 1.397 Simple Sequence Repeat (SSR) loci were discriminated from the sequences. From 306 putative, mainly non-synonymous SNVs located in CDS sequences, 191 were checked for their ability to characterize 23 Hevea genotypes by an allele-specific amplification technology. For 172 (90%), the nucleotide variation at the predicted genomic location was confirmed, thus validating the different steps from sequencing to the in silico detection of the SNVs. Conclusions This is the first study of the H. brasiliensis transcriptome, covering a wide range of tissues and organs, leading to the production of the first developed SNP markers. This process could be amplified to a larger set of in silico detected SNVs in expressed genes in order to increase the marker density in available and future genetic maps. The results obtained in this study will contribute to the H. brasiliensis genetic breeding program focused on improving of disease resistance and latex yield. PMID:24670056

2014-01-01

194

Distribution of a Nocardia brasiliensis Catalase Gene Fragment in Members of the Genera Nocardia, Gordona, and Rhodococcus  

Microsoft Academic Search

An immunodominant protein from Nocardia brasiliensis, P61, was subjected to amino-terminal and internal sequence analysis. Three sequences of 22, 17, and 38 residues, respectively, were obtained and compared with the protein database from GenBank by using the BLAST system. The sequences showed homology to some eukaryotic catalases and to a bromoperoxidase-catalase from Streptomyces violaceus. Its identity as a catalase was

LUCIO VERA-CABRERA; WENDY M. JOHNSON; OLIVERIO WELSH; FRANCISCO L. RESENDIZ-URESTI; MARIO C. SALINAS-CARMONA

1971-01-01

195

Distributional potential of the Triatoma brasiliensis species complex at present and under scenarios of future climate conditions  

PubMed Central

Background The Triatoma brasiliensis complex is a monophyletic group, comprising three species, one of which includes two subspecific taxa, distributed across 12 Brazilian states, in the caatinga and cerrado biomes. Members of the complex are diverse in terms of epidemiological importance, morphology, biology, ecology, and genetics. Triatoma b. brasiliensis is the most disease-relevant member of the complex in terms of epidemiology, extensive distribution, broad feeding preferences, broad ecological distribution, and high rates of infection with Trypanosoma cruzi; consequently, it is considered the principal vector of Chagas disease in northeastern Brazil. Methods We used ecological niche models to estimate potential distributions of all members of the complex, and evaluated the potential for suitable adjacent areas to be colonized; we also present first evaluations of potential for climate change-mediated distributional shifts. Models were developed using the GARP and Maxent algorithms. Results Models for three members of the complex (T. b. brasiliensis, N?=?332; T. b. macromelasoma, N?=?35; and T. juazeirensis, N?=?78) had significant distributional predictivity; however, models for T. sherlocki and T. melanica, both with very small sample sizes (N?=?7), did not yield predictions that performed better than random. Model projections onto future-climate scenarios indicated little broad-scale potential for change in the potential distribution of the complex through 2050. Conclusions This study suggests that T. b. brasiliensis is the member of the complex with the greatest distributional potential to colonize new areas: overall; however, the distribution of the complex appears relatively stable. These analyses offer key information to guide proactive monitoring and remediation activities to reduce risk of Chagas disease transmission. PMID:24886587

2014-01-01

196

Transcriptome analysis reveals novel features of the molecular events occurring in the laticifers of Hevea brasiliensis (para rubber tree)  

Microsoft Academic Search

Latex of Hevea brasiliensis (Willd. ex A, Juss.) Mull. Arg. (Brazilian rubber tree) contains 30–50% (w\\/w) of natural rubber (cis-1,4-polyisoprene), which is an important raw material for many industrial uses. In order to gain insights into the molecular events occurring in latex, we analyzed more than 20,000 cDNA-AFLP-based TDFs (transcription-derived fragments) and 1176 ESTs. The results revealed several novel features

Jae-Heung Ko; Keng-See Chow; Kyung-Hwan Han

2003-01-01

197

Parameters influencing stability and activity of a S-hydroxynitrile lyase from Hevea brasiliensis in two-phase systems  

Microsoft Academic Search

(S)-hydroxynitrile lyase from Hevea brasiliensis (EC 4.1.2.39)catalyzes the reversible formation of cyanohydrins from aldehydes of ketones and HCN. Stability and activity of hydroxynitrile lyase were investigated in citrate–phosphate buffer as well as in 11 different two-phase systems of buffer and water-immiscible organic solvents with a logPranging from 0.6 to 3.5. The formation of(S)-mandelonitrile from benzaldehyde and HCN was studied as

Michael Bauer; Herfried Griengl; Walter Steiner

1999-01-01

198

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

199

Roosting ecology and variation in adaptive and innate immune system function in the Brazilian free-tailed bat (Tadarida brasiliensis).  

PubMed

Bats have recently been implicated as reservoirs of important emerging diseases. However, few studies have examined immune responses in bats, and even fewer have evaluated these responses in an ecological context. We examined aspects of both innate and adaptive immune response in adult female Brazilian free-tailed bats (Tadarida brasiliensis) at four maternity roosts (two natural caves and two human-made bridges) in south-central Texas. Immune measurements included in vitro bactericidal ability of whole blood and in vivo T cell mediated response to mitogenic challenge. Bactericidal activity in T. brasiliensis varied with roosting ecology, but appears to be sensitive to colony-level effects. Blood from females living at one cave had significantly lower bactericidal ability than blood from females at three other sites. T cell mediated response in this species was associated with variation in roost ecology, with females from two caves having greater responses than females from two bridges. T cell mediated response and bactericidal activity were negatively correlated with one another within individuals that were tested for both. Variation in immunological response of T. brasiliensis is important for understanding the influence of the environment on the frequency and distribution of immunologically competent individuals and for understanding disease-host dynamics in this and other colonial species. PMID:19002470

Allen, Louise C; Turmelle, Amy S; Mendonça, Mary T; Navara, Kristen J; Kunz, Thomas H; McCracken, Gary F

2009-04-01

200

Foliar uptake of fog water and transport belowground alleviates drought effects in the cloud forest tree species, Drimys brasiliensis (Winteraceae).  

PubMed

Foliar water uptake (FWU) is a common water acquisition mechanism for plants inhabiting temperate fog-affected ecosystems, but the prevalence and consequences of this process for the water and carbon balance of tropical cloud forest species are unknown. We performed a series of experiments under field and glasshouse conditions using a combination of methods (sap flow, fluorescent apoplastic tracers and stable isotopes) to trace fog water movement from foliage to belowground components of Drimys brasiliensis. In addition, we measured leaf water potential, leaf gas exchange, leaf water repellency and growth of plants under contrasting soil water availabilities and fog exposure in glasshouse experiments to evaluate FWU effects on the water and carbon balance of D. brasiliensis saplings. Fog water diffused directly through leaf cuticles and contributed up to 42% of total foliar water content. FWU caused reversals in sap flow in stems and roots of up to 26% of daily maximum transpiration. Fog water transported through the xylem reached belowground pools and enhanced leaf water potential, photosynthesis, stomatal conductance and growth relative to plants sheltered from fog. Foliar uptake of fog water is an important water acquisition mechanism that can mitigate the deleterious effects of soil water deficits for D. brasiliensis. PMID:23534879

Eller, Cleiton B; Lima, Aline L; Oliveira, Rafael S

2013-07-01

201

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.

2012-01-01

202

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

1957-01-01

203

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

1971-01-01

204

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.

1981-01-01

205

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

2006-01-01

206

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

207

Oily yeasts as oleaginous cell factories.  

PubMed

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

2011-05-01

208

Identification of yeasts isolated from poultry meat.  

PubMed

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

2001-01-01

209

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

2004-01-01

210

Cloning and characterization of a novel cysteine protease gene (HbCP1) from Hevea brasiliensis.  

PubMed

The full-length cDNA encoding a cysteine protease,designated HbCP1, was isolated for the first time from Hevea brasiliensis by the rapid amplification of cDNA ends (RACE) method. HbCP1 contained a 1371 bp open reading frame encoding 457 amino acids.The deduced HbCP1 protein,which showed high identity to cysteine proteases of other plant species,was predicted to possess a putative repeat in toxin (RTX) domain at the N-terminal and a granulin (GRAN) domain at the C-terminal.Southern blot analysis indicated that the HbCP1 gene is present as a single copy in the rubber tree.Transcription pattern analysis revealed that HbCP1 had high transcription in laticifer,and low transcription in bark and leaf.The transcription of HbCP1 in latex was induced by ethylene and tapping.Cloning of the HbCP1 gene will enable us to further understand the molecular characterization of cysteine protease and its possible function in the rubber tree. PMID:19179756

Peng, Shi-Qing; Zhu, Jia-Hong; Li, Hui-Liang; Tian, Wei-Min

2008-12-01

211

Hevea brasiliensis cell suspension peroxidase: purification, characterization and application for dye decolorization  

PubMed Central

Peroxidases are oxidoreductase enzymes produced by most organisms. In this study, a peroxidase was purified from Hevea brasiliensis cell suspension by using anion exchange chromatography (DEAE-Sepharose), affinity chromatography (Con A-agarose) and preparative SDS-PAGE. The obtained enzyme appeared as a single band on SDS-PAGE with molecular mass of 70 kDa. Surprisingly, this purified peroxidase also had polyphenol oxidase activity. However, the biochemical characteristics were only studied in term of peroxidase because similar experiments in term of polyphenol oxidase have been reported in our pervious publication. The optimal pH of the purified peroxidase was 5.0 and its activity was retained at pH values between 5.0–10.0. The enzyme was heat stable over a wide range of temperatures (0–60°C), and less than 50% of its activity was lost at 70°C after incubation for 30 min. The enzyme was completely inhibited by ?-mercaptoethanol and strongly inhibited by NaN3; in addition, its properties indicated that it was a heme containing glycoprotein. This peroxidase could decolorize many dyes; aniline blue, bromocresol purple, brilliant green, crystal violet, fuchsin, malachite green, methyl green, methyl violet and water blue. The stability against high temperature and extreme pH supported that the enzyme could be a potential peroxidase source for special industrial applications. PMID:23402438

2013-01-01

212

Aid to a Declining Matriarch in the Giant Otter (Pteronura brasiliensis)  

PubMed Central

Scientists are increasingly revealing the commonalities between the intellectual, emotional and moral capacities of animals and humans. Providing assistance to elderly and ailing family members is a human trait rarely documented for wild animals, other than anecdotal accounts. Here I report observations of multiple forms of assistance to the declining matriarch of a habituated group of giant otters (Pteronura brasiliensis) in Manu National Park, Peru. The otter group had been observed annually for several years and all members were known individually. In 2007, the breeding female of the group failed to reproduce and appeared to be in physical decline. She begged from other family members 43 times over 41 contact hours and received food 11 times. Comparisons with 2004–2006 demonstrate that the family's behavior in 2007 constitutes a role-reversal, in which the majority of assistance and prey transfers accrued from young-to-old rather than from old-to-young. As in human societies, both non-adaptive and adaptive hypotheses could explain the family members' aid to their declining matriarch. I suggest that giant otter families may benefit from the knowledge and experience of an elderly matriarch and “grandparent helper,” consistent with the “Grandmother Hypothesis” of adaptive menopause in women. PMID:20613978

Davenport, Lisa C.

2010-01-01

213

A novel and enantioselective epoxide hydrolase from Aspergillus brasiliensis CCT 1435: purification and characterization.  

PubMed

A novel epoxide hydrolase from Aspergillus brasiliensis CCT1435 (AbEH) was cloned and overexpressed in Escherichia coli cells with a 6xHis-tag and purified by nickel affinity chromatography. Gel filtration analysis and circular dichroism measurements indicated that this novel AbEH is a homodimer in aqueous solution and contains the typical secondary structure of an ?/? hydrolase fold. The activity of AbEH was initially assessed using the fluorogenic probe O-(3,4-epoxybutyl) umbelliferone and was active in a broad range of pH (6-9) and temperature (25-45°C); showing optimum performance at pH 6.0 and 30°C. The Michaelis constant (KM) and maximum rate (Vmax) values were 495?M and 0.24?M/s, respectively. Racemic styrene oxide (SO) was used as a substrate to assess the AbEH activity and enantioselectivity, and 66% of the SO was hydrolyzed after only 5min of reaction, with the remaining (S)-SO ee exceeding 99% in a typical kinetic resolution behavior. The AbEH-catalyzed hydrolysis of SO was also evaluated in a biphasic system of water:isooctane; (R)-diol in 84% ee and unreacted (S)-SO in 36% ee were produced, with 43% conversion in 24h, indicating a discrete enantioconvergent behavior for AbEH. This novel epoxide hydrolase has biotechnological potential for the preparation of enantiopure epoxides or vicinal diols. PMID:23973866

Beloti, Lilian L; Costa, Bruna Z; Toledo, Marcelo A S; Santos, Clelton A; Crucello, Aline; Fávaro, Marianna T P; Santiago, André S; Mendes, Juliano S; Marsaioli, Anita J; Souza, Anete P

2013-10-01

214

Rubber (Hevea brasiliensis) seed oil toxicity effect and Linamarin compound analysis  

PubMed Central

Background The lipid fraction of rubber (Hevea brasiliensis (kunth. Muell)) seed was extracted and analyzed for toxicological effect. The toxicological compound such as linamarin in rubber seed oil (RSO) extracted using different solvents, such as hexane (RSOh), mixture of chloroform?+?methanol (RSOchl+mth) and ethanol (RSOeth) were also studied. Various methods analysis such as Fourier transforms infrared spectroscopy (FTIR) and colorimetric methods were carried out to determine the present of such compounds. Results FTIR spectrum of RSO did not show any presence of cyanide peak. The determination of cyanide by using colorimetric method was demonstrated no response of the cyanide in RSO and didn’t show any colored comparing with commercial cyanide which observed blue color. The results showed that no functional groups such as cyanide (C???N) associated with linamarin were observed. Toxicological test using rats was also conducted to further confirm the absence of such compounds. RSO did not show any toxic potential to the rats. Bioassay experiments using shrimps had been used as test organisms to evaluate the toxicity of linamarin extract from RSOh, RSOchl+mth and RSOeth and LC50 were found to be (211.70?%, 139.40?%, and 117.41?%, respectively). Conclusions This can be attributed no hazardous linamarin were found in RSO. PMID:22694753

2012-01-01

215

The acute phase response in parasite infection. Nippostrongylus brasiliensis in the mouse.  

PubMed Central

Systemic inflammatory reactions are a prominent feature of many parasitic infections and the cellular and humoral components of the acute phase reaction may have an impact on the host-parasite relationship. We examined serum changes of four acute phase reactants: alpha 1-proteinase inhibition (alpha 1Pi); complement C3; serum amyloid A protein (SAA); and serum amyloid P component (SAP), in mice undergoing a primary infection with Nippostrongylus brasiliensis. SAA and SAP showed changes within the first 2 days of infection indicating the presence of an acute phase response associated with inflammation in the lung. Alpha 1Pi and C3 serum levels were not altered. However, all four acute phase reactants were synthesized in greater amounts by primary cultures of hepatocytes taken from infected animals at this time. Subsequently, as parasite-mediated inflammatory changes occur in the gut, both serum and hepatocyte cultures demonstrate an acute inflammatory response in all four reactants. It is proposed that the early reaction between parasites and macrophage/monocyte lead to the release of a mediator of inflammation which initiates the hepatocyte response. In this infection, at least one of the APR is shown to localize to the site of inflammation influencing the host-parasite relationship. Images Figure 2 Figure 3 PMID:6204934

Lamontagne, L R; Gauldie, J; Befus, A D; McAdam, K P; Baltz, M L; Pepys, M B

1984-01-01

216

Molecular cloning, expression profiles, and characterization of a novel polyphenol oxidase (PPO) gene in Hevea brasiliensis.  

PubMed

The polyphenol oxidase (PPO) is involved in undesirable browning in many plant foods. Although the PPOs have been studied by several researchers, the isolation and expression profiles of PPO gene were not reported in rubber tree. In this study, a new PPO gene, HbPPO, was isolated from Hevea brasiliensis. The sequence alignment showed that HbPPO indicated high identities to plant PPOs and belonged to dicot branch. The cis-acting regulatory elements related to stress/hormone responses were predicted in the promoter region of HbPPO. Real-time RT-PCR analyses showed that HbPPO expression varied widely depending on different tissues and developmental stages of leaves. Besides being associated with tapping panel dryness, the HbPPO transcripts were regulated by ethrel, wounding, H2O2, and methyl jasmonate treatments. Moreover, the correlation between latex coagulation rate and PPO activity was further confirmed in this study. Our results lay the foundation for further analyzing the function of HbPPO in rubber tree. PMID:25051980

Li, Dejun; Deng, Zhi; Liu, Changren; Zhao, Manman; Guo, Huina; Xia, Zhihui; Liu, Hui

2014-10-01

217

Antioxidative polyphenols from Nigerian mistletoe Loranthus micranthus (Linn.) parasitizing on Hevea brasiliensis.  

PubMed

Two new phenolic glycosides, linamarin gallate (1) and walsuraside B (2), together with nine known compounds, catechin (3), epicatechin (4), epicatechin 3-O-gallate (5), epicatechin 3-O-(3-O-methyl)gallate (6), epicatechin 3-O-(3,5-O-dimethyl)gallate (7), epicatechin 3-O-(3,4,5-O-trimethyl)gallate (8), quercetin 3-O-?-d-glucopyranoside (9), rutin (10), and peltatoside (11), were isolated from the leafy twigs of Nigerian mistletoe Loranthus micranthus (Linn.) parasitic on Hevea brasiliensis. Compound 1 was characterized as an unusual cyanogenic glycoside, while compound 8 was isolated for the first time from a natural source. This is the first report of a cyanogenic glycoside from mistletoes. The structures of the new compounds were unambiguously elucidated by 1D ((1)H, (13)C), 2D NMR (COSY, HSQC, and HMBC) and by mass spectroscopy. The antioxidant activities of the isolated compounds (1-11) were evaluated using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay. PMID:23422225

Agbo, Matthias Onyebuchi; Lai, Daowan; Okoye, Festus B C; Osadebe, Patience O; Proksch, Peter

2013-04-01

218

Effects of Freshwater Discharge in Sandy Beach Populations: The Mole Crab Emerita brasiliensis in Uruguay  

NASA Astrophysics Data System (ADS)

Sandy beaches are ecosystems which are heavily affected by human activities. An example of this is freshwater discharges, which are known to change salinity, temperature and nutrient regimes and degrade nearshore environments. However, the effects of this kind of disturbance on sandy beach fauna have been little studied. This paper reports the spatial effects of a man-made freshwater canal discharge on the population structure, abundance and reproductive characteristics of the sandy beach mole crab Emerita brasiliensis. Along the 22 km of sandy beach sampled, the mole crab showed a marked longshore variability in population structure and abundance. Abundance of different population components (juveniles, males, females and ovigerous females) significantly decreased towards the canal. Population structure by sex and size, individual weight, fecundity and female maturity patterns at size also displayed a non-linear response to the distance from the freshwater discharge. Only the size structure of males did not follow this pattern. For males, spatial heterogeneity enhanced the detection of density-dependence at less disturbed sites. The authors conclude that artificial freshwater discharges could significantly influence the distribution, abundance and life-history traits of the biota of sandy beaches, and that further study of these ecosystems should include human activities as important factors affecting spatial and temporal trends. The need to consider different spatial and temporal scales in order to detect the effect of anthropogenically-driven impacts in sandy beach populations is stressed.

Lercari, D.; Defeo, O.

1999-10-01

219

Identification and characterization of the 14-3-3 gene family in Hevea brasiliensis.  

PubMed

The 14-3-3 proteins are a family of conserved phospho-specific binding proteins involved in diverse physiological processes. Although the genome-wide analysis of this family has been carried out in certain plant species, little is known about 14-3-3 protein genes in rubber tree (Hevea brasiliensis). In this study, we identified 10 14-3-3 protein genes (designated as HbGF14a to HbGF14j) in the latest rubber tree genome. A phylogenetic tree was constructed and found to demonstrate that HbGF14s can be divided into two major groups. Tissue-specific expression profiles showed that 10 HbGF14 were expressed in at least one of the tissues, which suggested that HbGF14s participated in numerous cellular processes. The 10 HbGF14s responded to jasmonic acid (JA) and ethylene (ET) treatment, which suggested that these HbGF14s were involved in response to JA and ET signaling. The target of HbGF14c protein was related to small rubber particle protein, a major rubber particle protein that is involved in rubber biosynthesis. These findings suggested that 14-3-3 proteins may be involved in the regulation of natural rubber biosynthesis. PMID:24751399

Yang, Zi-Ping; Li, Hui-Liang; Guo, Dong; Tang, Xiao; Peng, Shi-Qing

2014-07-01

220

The small RNA profile in latex from Hevea brasiliensis trees is affected by tapping panel dryness.  

PubMed

Natural rubber is harvested by tapping Hevea brasiliensis (Willd. ex A. Juss.) Müll. Arg. Harvesting stress can lead to tapping panel dryness (TPD). MicroRNAs (miRNAs) are induced by abiotic stress and regulate gene expression by targeting the cleavage or translational inhibition of target messenger RNAs. This study set out to sequence miRNAs expressed in latex cells and to identify TPD-related putative targets. Deep sequencing of small RNAs was carried out on latex from trees affected by TPD using Solexa technology. The most abundant small RNA class size was 21 nucleotides for TPD trees compared with 24 nucleotides in healthy trees. By combining the LeARN pipeline, data from the Plant MicroRNA database and Hevea EST sequences, we identified 19 additional conserved and four putative species-specific miRNA families not found in previous studies on rubber. The relative transcript abundance of the Hbpre-MIR159b gene increased with TPD. This study revealed a small RNA-specific signature of TPD-affected trees. Both RNA degradation and a shift in miRNA biogenesis are suggested to explain the general decline in small RNAs and, particularly, in miRNAs. PMID:24218245

Gébelin, Virginie; Leclercq, Julie; Kuswanhadi; Argout, Xavier; Chaidamsari, Tetty; Hu, Songnian; Tang, Chaorong; Sarah, Gautier; Yang, Meng; Montoro, Pascal

2013-10-01

221

Activation of the Na sup + ,K sup + -ATPase in Narcine brasiliensis  

SciTech Connect

The in vivo activation and turnover rates of the sodium pump (Na{sup +},K{sup +}-ATPase) were investigated in the electrocytes of the electric organ of the elasmobranch Narcine brasiliensis. The Narcine electric organ appears to be an excellent model for the study of sodium pump activation in an excitable tissue. The sodium transmembrane gradient and high-energy phosphagens were concurrently measured by {sup 23}Na and {sup 31}P NMR spectroscopy. The resting electric organ, which depends primarily on anaerobic metabolism displays a high concentration of phosphocreatin (PCr). It has an intracellular sodium concentration ((Na{sup +}){sub i}) of 20{plus minus}10 milliequivalents/liter as estimated by NMR. Electrical stimulation of the nerves innervating the electric organ results in an increase in (Na{sup +}){sub i} in the electrolyte and rapid depletion of PCr. Ouabain causes an 85% decrease in utilization of high-energy phosphagens, indicating that rapid PCr turnover in this tissue is mainly due to Na{sup +},K{sup +}-ATPase activity. From these data the authors can determine that the rate of sodium pump turnover increases by >3 orders of magnitude within several hundred milliseconds. The authors conclude that cholinergic stimulation of the electric organ causes a rapid and extremely large increase in sodium pump turnover, which is regulated predominantly by factors other than (Na{sup +}){sub i}.

Blum, H.; Nioka, Shoko; Johnson, R.G. Jr. (Univ. of Pennsylvania School of Medicine, Philadelphia (USA))

1990-02-01

222

Characterization of a cassiicolin-encoding gene from Corynespora cassiicola, pathogen of rubber tree (Hevea brasiliensis).  

PubMed

Corynespora Leaf Fall (CLF) is a major disease of rubber tree (Hevea brasiliensis) caused by the Ascomycota Corynespora cassiicola. Here we describe the cloning and characterization of a gene encoding cassiicolin (Cas), a glycosylated cystein-rich small secreted protein (SSP) identified as a potential CLF disease effector in rubber tree. Three isolates with contrasted levels of aggressiveness were analyzed comparatively. The cassiicolin gene was detected - and the toxin successfully purified - from the isolates with high and medium aggressiveness (CCP and CCAM3 respectively) but not from the isolate with the lowest aggressiveness (CCAM1), suggesting the existence of a different disease effector in the later. CCP and CCAM3 carried strictly identical cassiicolin genes and produced toxins of identical mass, as evidence by mass spectrometry analysis, thus suggesting conserved post-translational modifications in addition to sequence identity. The differences in aggressiveness between CCP and CCAM3 may be attributed to differences in cassiicolin transcript levels rather than qualitative variations in cassiicolin structure. Cassiicolin may play an important role in the early phase of infection since a peak of cassiicolin transcripts occurred in 1 or 2 days after inoculation (before the occurrence of the first symptoms), in both the tolerant and the susceptible cultivars. PMID:22325885

Déon, Marine; Bourré, Yanice; Gimenez, Stéphanie; Berger, Angélique; Bieysse, Daniel; de Lamotte, Frédéric; Poncet, Joël; Roussel, Véronique; Bonnot, François; Oliver, Gérald; Franchel, Jérôme; Seguin, Marc; Leroy, Thierry; Roeckel-Drevet, Patricia; Pujade-Renaud, Valérie

2012-04-01

223

Diversity of the cassiicolin gene in Corynespora cassiicola and relation with the pathogenicity in Hevea brasiliensis.  

PubMed

Corynespora cassiicola is an important plant pathogenic Ascomycete causing the damaging Corynespora Leaf Fall (CLF) disease in rubber tree (Hevea brasiliensis). A small secreted glycoprotein named cassiicolin was previously described as an important effector of C. cassiicola. In this study, the diversity of the cassiicolin-encoding gene was analysed in C. cassiicola isolates sampled from various hosts and geographical origins. A cassiicolin gene was detected in 47 % of the isolates, encoding up to six distinct protein isoforms. In three isolates, two gene variants encoding cassiicolin isoforms Cas2 and Cas6 were found in the same isolate. A phylogenetic tree based on four combined loci and elucidating the diversity of the whole collection was strongly structured by the toxin class, as defined by the cassiicolin isoform. The isolates carrying the Cas1 gene (toxin class Cas1), all grouped in the same highly supported clade, were found the most aggressive on two rubber tree cultivars. Some isolates in which no Cas gene was detected could nevertheless generate moderate symptoms, suggesting the existence of other yet uncharacterized effectors. This study provides a useful base for future studies of C. cassiicola population biology and epidemiological surveys in various host plants. PMID:24433675

Déon, Marine; Fumanal, Boris; Gimenez, Stéphanie; Bieysse, Daniel; Oliveira, Ricardo R; Shuib, Siti Shuhada; Breton, Frédéric; Elumalai, Sunderasan; Vida, João B; Seguin, Marc; Leroy, Thierry; Roeckel-Drevet, Patricia; Pujade-Renaud, Valérie

2014-01-01

224

Fat content in migratory central Arizona Brazilian free-tailed bats, Tadarida brasiliensis (Molossidae)  

USGS Publications Warehouse

Fat content of migratory Tadarida brasiliensis was determined during the spring, summer and fall of 1972 in the Verde Valley of Arizona. Fat indices were highest in March arrivals, generally declined throughout the summer, and were lowest in September. In both 1972 and 1973 bats had arrived at the study area by mid-March. In 1971 bats were last noted at the area in mid-October while in 1972 they had disappeared by late September. On the basis on physiological calculations it is estimated that bats collected in March 1972 possessed sufficient fat reserves to carry them a mean distance of 716 km north of the study area while September bats had only enough reserves to fly 386 km southward, about 160 km short of the nearest known Sonora wintering locality. It is suggested that in spring the bats may have a more rigidly timed migration and so put on excess fat to counter an uncertain environment to the north. The fall migration may be triggered by more unpredictable events, such as the passage of cold fronts, and less fat reserves may be required for movements into more favorable southern locales.

O'Shea, Thomas J.

1976-01-01

225

Elucidation of the mode of substrate binding to hydroxynitrile lyase from Hevea brasiliensis.  

PubMed

The hydroxynitrile lyase from Hevea brasiliensis (Hb-HNL) is used as a catalyst in enantiospecific syntheses of alpha-hydroxynitriles from aldehydes and methyl-ketones. The catalyzed reaction represents one of the few industrially relevant examples of enzyme mediated C-C coupling reactions. In this work, we modeled Hb-HNL substrate complexes that have as yet proven inaccessible to experimental structure determination and were able to identify two binding modes for the natural substrate acetone cyanohydrin in docking simulations. Discrimination of the two alternatives was achieved by modeling complexes with two different chiral cyanohydrins followed by an analysis of the respective relative binding energies from molecular mechanics and thermodynamic integration. Only for one of the alternative binding modes the experimentally established S-selectivity of the enzyme was correctly predicted. Our results yielded further support for an enzymatic mechanism involving the catalytic triad Ser80, His235, and Asp207 as a general acid/base. A pivotal role was ascribed to Lys236, which seems to be crucial for enzymatic activity at low pH values. In addition, the modeling calculations provided possible explanations for the observed substrate and enantioselectivity of the enzyme that rationalize available mutational data and will be the basis for future protein engineering efforts. PMID:11354003

Gruber, K

2001-07-01

226

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

2012-02-01

227

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

228

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

229

Yeast (in press) Published online in Wiley InterScience  

E-print Network

Yeast Yeast (in press) Published online in Wiley InterScience (www.interscience.wiley.com) 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.

230

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

231

Yeast adaptation on softwood prehydrolysate.  

PubMed

Several strains and genera of yeast, including Saccharomyces cerevisiae D5A, Pachysolen tannophilus, S. cerevisiae K-1, Brettanomyces custersii, Candida shehatae, and Candida acidothermophilum, are screened for growth on dilute acid-pretreated softwood prehydrolysate. Selected softwood species found in forest underbrush of the western United States, which contain predominantly hexosan hemicellulose, were studied. This phase of the work emphasized debarked Douglas fir. The two best initial isolates were gradually selected for improved growth by adaptation to increasing prehydrolysate concentrations in batch culture, with due consideration of nutrient requirements. Microaerophilic conditions were evaluated to encourage tolerance of pretreatment hydrolysate, as well as ethanol product. Adaptation and simultaneous saccharification and fermentation (SSF) results are used to illustrate improved performance with an adapted strain, compared to the wild type. PMID:9627379

Keller, F A; Bates, D; Ruiz, R; Nguyen, Q

1998-01-01

232

Extracellular Deoxyribonuclease Production by Yeasts  

PubMed Central

A total of 20 genera of yeasts and yeastlike organisms were tested for their ability to produce an extracellular deoxyribonuclease. Results indicate that ability to produce the enzyme appears to be a specific characteristic of the three genera Rhodotorula, Cryptococcus, and Tremella. A single strain of Endomycopsis fibuligera was also shown to be positive for the enzyme. In comparing the ability of the organisms to excrete extracellular deoxyribonuclease with their ability to produce urease, a surprisingly close correlation was found. With the exception of Lipomyces starkeyi, all the organisms which were deoxyribonuclease-negative were also urease-negative. Of those organisms which were deoxyribonuclease-positive, only E. fibuligera was urease-negative. The ability of cryptococci to produce extracellular deoxyribonuclease is discussed in relation to the implication which this finding may have for the taxonomy and phylogeny of the genus. PMID:5354946

Cazin, John; Kozel, Thomas R.; Lupan, David M.; Burt, Wayne R.

1969-01-01

233

Extracellular deoxyribonuclease production by yeasts.  

PubMed

A total of 20 genera of yeasts and yeastlike organisms were tested for their ability to produce an extracellular deoxyribonuclease. Results indicate that ability to produce the enzyme appears to be a specific characteristic of the three genera Rhodotorula, Cryptococcus, and Tremella. A single strain of Endomycopsis fibuligera was also shown to be positive for the enzyme. In comparing the ability of the organisms to excrete extracellular deoxyribonuclease with their ability to produce urease, a surprisingly close correlation was found. With the exception of Lipomyces starkeyi, all the organisms which were deoxyribonuclease-negative were also urease-negative. Of those organisms which were deoxyribonuclease-positive, only E. fibuligera was urease-negative. The ability of cryptococci to produce extracellular deoxyribonuclease is discussed in relation to the implication which this finding may have for the taxonomy and phylogeny of the genus. PMID:5354946

Cazin, J; Kozel, T R; Lupan, D M; Burt, W R

1969-11-01

234

Biology of the pathogenic yeast Candida glabrata.  

PubMed

The yeasts, being favorite eukaryotic microorganisms used in food industry and biotechnologies for production of biomass and various substances, are also used as model organisms in genetic manipulation, molecular and biological research. In this respect, Saccharomyces cerevisiae is the best-known species but current situation in medicine and industry requires the use of other species. Here we summarize the basic taxonomic, morphological, physiological, genetic, etc. information about the pathogenic yeast Candida glabrata that is evolutionarily very closely related to baker's yeast. PMID:16821705

Bialková, A; Subík, J

2006-01-01

235

Corning and Kroger turn whey to yeast  

SciTech Connect

It is reported that Corning and Kroger intend to build a 35,000 sq. ft. plant in Winchester, Ky., that will turn whey into bakers' yeast. The plant will convert whey from Kroger's dairies into bakers' yeast, supplying about 60% of the yeast needed for nine Kroger bakeries. It will also produce syrups and whey protein concentrate for use in other food processing activities. In addition to making useful products, the project will convert the whey to glucose and galactose. The protein component of the whey will be concentrated and used in various foods and feeds.

Not Available

1981-11-16

236

Yeast Transformation (introducing plasmid vector into a yeast strain): This protocol is a modification (shortened version) of "The BEST  

E-print Network

Yeast Transformation (introducing plasmid vector into a yeast strain): This protocol://www.umanitoba.ca/medicine/biochem/gietz/Trafo.html) 1. Inoculate 5 ml of YPD with a yeast colony from plate. 2. Grow culture overnight at 300 C. 3 and centrifuging at 1750xg (high speed in clinical centrifuge) for 2 minutes. 6. Carefully pour media off of yeast

237

Histochemical study of the hepatopancreas in adult females of the pink-shrimp Farfantepenaeus brasiliensis Latreille, 1817.  

PubMed

This study provides histochemical data of the hepatopancreatic cells of adult female pink-shrimp (Farfantepenaeus brasiliensis) at two different developmental stages (those with developed gonads and those with exhausted gonads). The F. brasiliensis females were collected in seawater off the Guarapari coast, Espirito Santo, Brazil. Five cell types were identified in this digestive gland: B (vesicular), E (embryonic), F (fibrillar), M (basal) and R (resorptive). The digestive gland was stained with the following techniques: PAS/Alcian blue (for polysaccharides), bromophenol blue (for protein), von Kossa (for bound calcium) and Baker (for lipids). Acid glycoconjugates were found inside vacuoles in the R cells, while neutral polysaccharides were present in the B cells and near to the microvilli. In females with exhausted gonads polysaccharides were also seen in the intertubular spaces and inside the lumina of the tubules. The F and M cells were the most marked by the presence of large amounts of proteins observed in R cells and also inside the vacuoles of B cells. The bound calcium was mainly found in the F and M cells. The F cells showed strong positive staining for lipid while the R cell only stained weakly. The E cells did not react to any of the applied staining techniques. The similarities in the histochemical composition of these hepatopancreatic cells in females with developed gonads, compared to exhausted ones, is justified by the fact that transfer of these elements to the oocytes occurs, in significant quantity, only during the initial stages of gonadal development in F. brasiliensis. Also, they may be more related to the molt stage, as in the case of calcium salts. PMID:23992941

Nunes, Erika Takagi; Braga, Adriane Araújo; Camargo-Mathias, Maria Izabel

2014-01-01

238

Spatial analysis of egg distribution and geographic changes in the spawning habitat of the Brazilian sardine Sardinella brasiliensis.  

PubMed

This paper establishes the spawning habitat of the Brazilian sardine Sardinella brasiliensis and investigates the spatial variability of egg density and its relation with oceanographic conditions in the shelf of the south-east Brazil Bight (SBB). The spawning habitats of S. brasiliensis have been defined in terms of spatial models of egg density, temperature-salinity plots, quotient (Q) analysis and remote sensing data. Quotient curves (Q(C)) were constructed using the geographic distribution of egg density, temperature and salinity from samples collected during nine survey cruises between 1976 and 1993. The interannual sea surface temperature (SST) variability was determined using principal component analysis on the SST anomalies (SSTA) estimated from remote sensing data over the period between 1985 and 2007. The spatial pattern of egg occurrences in the SBB indicated that the largest concentration occurred between Paranaguá and São Sebastião. Spawning habitat expanded and contracted during the years, fluctuating around Paranaguá. In January 1978 and January 1993, eggs were found nearly everywhere along the inner shelf of the SBB, while in January 1988 and 1991 spawning had contracted to their southernmost position. The SSTA maps for the spawning periods showed that in the case of habitat expansion (1993 only) anomalies over the SBB were zero or slightly negative, whereas for the contraction period anomalies were all positive. Sardinella brasiliensis is capable of exploring suitable spawning sites provided by the entrainment of the colder and less-saline South Atlantic Central Water onto the shelf by means of both coastal wind-driven (to the north-east of the SBB) and meander-induced (to the south-west of the SBB) upwelling. PMID:21155781

Gigliotti, E S; Gherardi, D F M; Paes, E T; Souza, R B; Katsuragawa, M

2010-12-01

239

De novo assembly and transcriptome analysis of the rubber tree (Hevea brasiliensis) and SNP markers development for rubber biosynthesis pathways.  

PubMed

Hevea brasiliensis (Willd. Ex Adr. Juss.) Muell.-Arg. is the primary source of natural rubber that is native to the Amazon rainforest. The singular properties of natural rubber make it superior to and competitive with synthetic rubber for use in several applications. Here, we performed RNA sequencing (RNA-seq) of H. brasiliensis bark on the Illumina GAIIx platform, which generated 179,326,804 raw reads on the Illumina GAIIx platform. A total of 50,384 contigs that were over 400 bp in size were obtained and subjected to further analyses. A similarity search against the non-redundant (nr) protein database returned 32,018 (63%) positive BLASTx hits. The transcriptome analysis was annotated using the clusters of orthologous groups (COG), gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Pfam databases. A search for putative molecular marker was performed to identify simple sequence repeats (SSRs) and single nucleotide polymorphisms (SNPs). In total, 17,927 SSRs and 404,114 SNPs were detected. Finally, we selected sequences that were identified as belonging to the mevalonate (MVA) and 2-C-methyl-D-erythritol 4-phosphate (MEP) pathways, which are involved in rubber biosynthesis, to validate the SNP markers. A total of 78 SNPs were validated in 36 genotypes of H. brasiliensis. This new dataset represents a powerful information source for rubber tree bark genes and will be an important tool for the development of microsatellites and SNP markers for use in future genetic analyses such as genetic linkage mapping, quantitative trait loci identification, investigations of linkage disequilibrium and marker-assisted selection. PMID:25048025

Mantello, Camila Campos; Cardoso-Silva, Claudio Benicio; da Silva, Carla Cristina; de Souza, Livia Moura; Scaloppi Junior, Erivaldo José; de Souza Gonçalves, Paulo; Vicentini, Renato; de Souza, Anete Pereira

2014-01-01

240

Kinetochore Structure: Pulling Answers from Yeast  

E-print Network

Despite the identification of multiple kinetochore proteins, their structure and organization has remained unclear. New work uses electron microscopy to visualize isolated budding yeast kinetochore particles and reveal the ...

Cheeseman, Iain M.

241

Protection from nitrosative stress by yeast flavohemoglobin  

PubMed Central

Yeast hemoglobin was discovered close to half a century ago, but its function has remained unknown. Herein, we report that this flavohemoglobin protects Saccharomyces cerevisiae from nitrosative stress. Deletion of the flavohemoglobin gene (YHB1) abolished the nitric oxide (NO)-consuming activity of yeast cells. Levels of protein nitrosylation were more than 10-fold higher in yhb1 mutant yeast than in isogenic wild-type cells after incubation with NO donors. Growth of mutant cells was inhibited by a nitrosative challenge that had little effect on wild-type cells, whereas the resistance of mutant cells to oxidative stress was unimpaired. Protection conferred by yeast flavohemoglobin against NO and S-nitrosothiols was seen under both anaerobic and aerobic conditions, consistent with a primary function in NO detoxification. A phylogenetic analysis indicated that protection from nitrosative stress is likely to be a conserved function among microorganismal flavohemoglobins. Flavohemoglobin is therefore a potential target for antimicrobial therapy. PMID:10758168

Liu, Limin; Zeng, Ming; Hausladen, Alfred; Heitman, Joseph; Stamler, Jonathan S.

2000-01-01

242

Prion formation by a yeast GLFG nucleoporin  

E-print Network

The self-assembly of proteins into higher order structures is both central to normal biology and a dominant force in disease. Certain glutamine/asparagine (Q/N)-rich proteins in the budding yeast Saccharomyces cerevisiae ...

Halfmann, Randal

243

Comparative Functional Genomics of the Fission Yeasts  

E-print Network

The fission yeast clade—comprising Schizosaccharomyces pombe, S. octosporus, S. cryophilus, and S. japonicus—occupies the basal branch of Ascomycete fungi and is an important model of eukaryote biology. A comparative ...

Regev, Aviv

244

Mitochondria, metabolism, and aging in yeast  

Microsoft Academic Search

\\u000a Quantitative and qualitative changes in metabolism take place when the lifespan is extended in yeast either by genetic or\\u000a nutritional manipulation. In particular, remodeling of mitochondrial function occurs, and the relationship between this organelle\\u000a and other cellular compartments moves to the fore. Two separate pathways, the retrograde response and calorie restriction,\\u000a operate as metabolic mechanisms for life extension in yeast.

S. Michal Jazwinski

245

Yeast flocculation: what brewers should know  

Microsoft Academic Search

For many industrial applications in which the yeast Saccharomyces cerevisiae is used, e.g. beer, wine and alcohol production, appropriate flocculation behaviour is certainly one of the most important characteristics of a good production strain. Yeast flocculation is a very complex process that depends on the expression of specific flocculation genes such as FLO1, FLO5, FLO8 and FLO11. The transcriptional activity

K. J. Verstrepen; G. Derdelinckx; H. Verachtert; F. R. Delvaux

2003-01-01

246

Cooperative regulation in yeast cell cycle network  

E-print Network

We define a measure of cooperativity for gene regulatory networks which we propose should be maximized under a demand for energy efficiency. We investigate its dependence on network size, connectivity and the fraction of repressory/activatory interactions. Next, we consider the cell-cycle regulatory network of the yeast, Saccharomyces cerevisiae, as a case study and calculate its degree of cooperativity. A comparison with random networks of similar size and composition reveals that the yeast's cell-cycle regulation is exceptionally cooperative.

Nese Aral; Alkan Kabakcioglu

2014-06-28

247

Identification of the Hevea brasiliensis AP2/ERF superfamily by RNA sequencing  

PubMed Central

Background Rubber tree (Hevea brasiliensis) laticifers are the source of natural rubber. Rubber production depends on endogenous and exogenous ethylene (ethephon). AP2/ERF transcription factors, and especially Ethylene-Response Factors, play a crucial role in plant development and response to biotic and abiotic stresses. This study set out to sequence transcript expressed in various tissues using next-generation sequencing and to identify AP2/ERF superfamily in the rubber tree. Results The 454 sequencing technique was used to produce five tissue-type transcript libraries (leaf, bark, latex, embryogenic tissues and root). Reads from all libraries were pooled and reassembled to improve mRNA lengths and produce a global library. One hundred and seventy-three AP2/ERF contigs were identified by in silico analysis based on the amino acid sequence of the conserved AP2 domain from the global library. The 142 contigs with the full AP2 domain were classified into three main families (20 AP2 members, 115 ERF members divided into 11 groups, and 4 RAV members) and 3 soloist members. Fifty-nine AP2/ERF transcripts were found in latex. Alongside the microRNA172 already described in plants, eleven additional microRNAs were predicted to inhibit Hevea AP2/ERF transcripts. Conclusions Hevea has a similar number of AP2/ERF genes to that of other dicot species. We adapted the alignment and classification methods to data from next-generation sequencing techniques to provide reliable information. We observed several specific features for the ERF family. Three HbSoloist members form a group in Hevea. Several AP2/ERF genes highly expressed in latex suggest they have a specific function in Hevea. The analysis of AP2/ERF transcripts in Hevea presented here provides the basis for studying the molecular regulation of latex production in response to abiotic stresses and latex cell differentiation. PMID:23324139

2013-01-01

248

Impact of age of rubber (Hevea brasiliensis) plantation on earthworm communities of West Tripura (India).  

PubMed

A comparative analysis of earthworm communities was carried out in the rubber plantations (Hevea brasiliensis) of different age groups in West Tripura to understand the impact of such exotic and monoculture plantation in biodiversity conservation. Earthworm communities were studied on monthly basis over a period of one year (2006-2007) in the 3, 10, 14, 20 and 25 year-old plantations. Among twelve earthworm species collected from the studied sites, six species belonged to Octochaetidae [Eutyphoeus assomensis Stephenson, Eutyphoeus comillahnus Michaelsen, Lennogaster chittagongensis (Stephensen), Octochaetona beatrix Gates, Dichogaster offinis Michaelsen, Lennogaster yeicus (Stephensen)], two species each to Megascolecidae [Metaphire houlleti (Perrier), Konchurio sp. 1] and Moniligastridae [Drowida nepalensis Michaelsen, Drawida papillifer papillifer Stephenson], one species each to Glossoscolecidae [Pontoscolex corethrurus (Muller)] and Ocnerodrilidae [Gordiodrilus elegans Beddard]. Exotic species P corethrurus, M. houlleti and native peregrine species like D. nepolensis and D. papillifer papillifer were distributed in all the age groups of plantation, while other species showed restricted distribution. P. corethrurus contributed more than 60% biomass and 70% density of earthworm communities in rubber plantation. With aging of rubber plantations both the densities and biomasses of earthworms increased. High contents of polyphenol, flavonoid and lignin in the litters of 3 and 10 year-old-rubber plantations through their effects on food intake, probably resulted to low biomass values of earthworms in those age groups of plantation. With further increase in the age of plantations beyond 10 years, polyphenol, flavonoid and lignin contents decreased. Accordingly the biomass of earthworms increased with increase in the age of plantation. Soil moisture increased with increase in the age of plantation and there was a good positive correlation between soil moisture and earthworm biomass (p < 0.01). Density, biomass and dominance of earthworms increased while species diversity, species richness and species evenness of earthworm community were decreased with increase in the age of rubber plantation. PMID:24006808

Chaudhuri, P S; Bhattacharjee, Subhalaxmi; Dey, Animesh; Chattopadhyay, Sharmila; Bhattacharya, Dipto

2013-01-01

249

Physiological and Molecular Responses to Variation of Light Intensity in Rubber Tree (Hevea brasiliensis Muell. Arg.)  

PubMed Central

Light is one of most important factors to plants because it is necessary for photosynthesis. In this study, physiological and gene expression analyses under different light intensities were performed in the seedlings of rubber tree (Hevea brasiliensis) clone GT1. When light intensity increased from 20 to 1000 µmol m?2 s?1, there was no effect on the maximal quantum yield of photosystem II (PSII) photochemistry (Fv/Fm), indicating that high light intensity did not damage the structure and function of PSII reaction center. However, the effective photochemical quantum yield of PSII (Y(II)), photochemical quenching coefficient (qP), electron transfer rate (ETR), and coefficient of photochemical fluorescence quenching assuming interconnected PSII antennae (qL) were increased significantly as the light intensity increased, reached a maximum at 200 µmol m?2 s?1, but decreased from 400 µmol m?2 s?1. These results suggested that the PSII photochemistry showed an optimum performance at 200 µmol m?2 s?1 light intensity. The chlorophyll content was increased along with the increase of light intensity when it was no more than 400 µmol m?2 s?1. Since increasing light intensity caused significant increase in H2O2 content and decreases in the per unit activity of antioxidant enzymes SOD and POD, but the malondialdehyde (MDA) content was preserved at a low level even under high light intensity of 1000 µmol m?2 s?1, suggesting that high light irradiation did not induce membrane lipid peroxidation in rubber tree. Moreover, expressions of antioxidant-related genes were significantly up-regulated with the increase of light intensity. They reached the maximum expression at 400 µmol m?2 s?1, but decreased at 1000 µmol m?2 s?1. In conclusion, rubber tree could endure strong light irradiation via a specific mechanism. Adaptation to high light intensity is a complex process by regulating antioxidant enzymes activities, chloroplast formation, and related genes expressions in rubber tree. PMID:24586839

Wang, Li-feng

2014-01-01

250

RNA sequencing read depth requirement for optimal transcriptome coverage in Hevea brasiliensis  

PubMed Central

Background One of the concerns of assembling de novo transcriptomes is determining the amount of read sequences required to ensure a comprehensive coverage of genes expressed in a particular sample. In this report, we describe the use of Illumina paired-end RNA-Seq (PE RNA-Seq) reads from Hevea brasiliensis (rubber tree) bark to devise a transcript mapping approach for the estimation of the read amount needed for deep transcriptome coverage. Findings We optimized the assembly of a Hevea bark transcriptome based on 16 Gb Illumina PE RNA-Seq reads using the Oases assembler across a range of k-mer sizes. We then assessed assembly quality based on transcript N50 length and transcript mapping statistics in relation to (a) known Hevea cDNAs with complete open reading frames, (b) a set of core eukaryotic genes and (c) Hevea genome scaffolds. This was followed by a systematic transcript mapping process where sub-assemblies from a series of incremental amounts of bark transcripts were aligned to transcripts from the entire bark transcriptome assembly. The exercise served to relate read amounts to the degree of transcript mapping level, the latter being an indicator of the coverage of gene transcripts expressed in the sample. As read amounts or datasize increased toward 16 Gb, the number of transcripts mapped to the entire bark assembly approached saturation. A colour matrix was subsequently generated to illustrate sequencing depth requirement in relation to the degree of coverage of total sample transcripts. Conclusions We devised a procedure, the “transcript mapping saturation test”, to estimate the amount of RNA-Seq reads needed for deep coverage of transcriptomes. For Hevea de novo assembly, we propose generating between 5–8 Gb reads, whereby around 90% transcript coverage could be achieved with optimized k-mers and transcript N50 length. The principle behind this methodology may also be applied to other non-model plants, or with reads from other second generation sequencing platforms. PMID:24484543

2014-01-01

251

Catalytic mechanism of hydroxynitrile lyase from Hevea brasiliensis: a theoretical investigation.  

PubMed

Density functional theory (DFT) calculations using the hybrid functional B3LYP have been performed to investigate the catalytic mechanism of hydroxynitrile lyase from Hevea brasiliensis (Hb-HNL). This enzyme catalyzes the cleavage of acetone cyanohydrin to hydrocyanic acid plus acetone. Two models (A and B) of the active site consisting of 105 and 155 atoms, respectively, were constructed on the basis of the crystal structure. Good consistency between the two models provides a verification of the proposed mechanism. Our calculations show that the catalytic reaction proceeds via three elementary steps: (1) deprotonation of the OH-Ser80 by His235 and concomitant abstraction of a proton from the substrate hydroxyl by Ser80; (2) the C-C bond cleavage of the acetone cyanohydrin; and (3) protonation of the cleaved cyanide by His235. The cleavage of the C-C bond is the rate-limiting step with the overall free energy barrier of 13.5 kcal/mol for relatively smaller model A (14.9 kcal/mol for a larger model B) in the protein environment, which is in good agreement with experimental rate. The present results give support to the previously proposed general acid/base catalytic mechanism, in which the catalytic triad acts as a general acid/base. Moreover, the calculated results for model C, with the positive charge of Lys236 removed from model A, show that Lys236 with the positive charge plays a vital role in lowering the reaction barrier of the rate-determining and helps in stabilizing the negatively charged CN(-) by forming a hydrogen bond with the substrate, consistent with the experimental analysis. PMID:20593768

Cui, Feng-Chao; Pan, Xiao-Liang; Liu, Jing-Yao

2010-07-29

252

Three-dimensional structures of enzyme-substrate complexes of the hydroxynitrile lyase from Hevea brasiliensis.  

PubMed

The 3D structures of complexes between the hydroxynitrile lyase from Hevea brasiliensis (Hb-HNL) and several substrate and/or inhibitor molecules, including trichloracetaldehyde, hexafluoracetone, acetone, and rhodanide, were determined by X-ray crystallography. The complex with trichloracetaldehyde showed a covalent linkage between the protein and the inhibitor, which had apparently resulted from nucleophilic attack of the catalytic Ser80-Ogamma. All other complexes showed the substrate or inhibitor molecule merely hydrogen bonded to the protein. In addition, the native crystal structure of Hb-HNL was redetermined at cryo-temperature and at room temperature, eliminating previous uncertainties concerning residual electron density within the active site, and leading to the observation of two conserved water molecules. One of them was found to be conserved in all complex structures and appears to have mainly structural significance. The other water molecule is conserved in all structures except for the complex with rhodanide; it is hydrogen bonded to the imidazole of the catalytic His235 and appears to affect the Hb-HNL catalyzed reaction. The observed 3D structural data suggest implications for the enzyme mechanism. It appears that the enzyme-catalyzed cyanohydrin formation is unlikely to proceed via a hemiacetal or hemiketal intermediate covalently attached to the enzyme, despite the observation of such an intermediate for the complex with trichloracetaldehyde. Instead, the data are consistent with a mechanism where the incoming substrate is activated by hydrogen bonding with its carbonyl oxygen to the Ser80 and Thr11 hydroxy groups. A hydrogen cyanide molecule subsequently replaces a water molecule and is deprotonated presumably by the His235 base. Deprotonation is facilitated by the proximity of the positive charge of the Lys236 side chain. PMID:10548044

Zuegg, J; Gruber, K; Gugganig, M; Wagner, U G; Kratky, C

1999-10-01

253

[Yeasts--biosorbents of heavy metals].  

PubMed

The sharp increase of the level of environment pollution by heavy metals caused the increase of interest to the problem of live organisms (including microorganisms) resistance to these metals. Biosorption is one of the mechanisms of microorganisms resistance to heavy metals. Yeasts as biosorbents are of special interest. An analysis of the data from literature have shown that the yeast biomass may be used successfully as biosorption material for such metals as Ag, Au, Cd, Co, Cr, Cu, Ni, Pb, U, Th, Zn. Yeasts of genera Saccharomyces, Candida, Pichia are efficient biosorbents of metals. The sorptional system estimation is based on the classic sorption isotherm obtained in the course of equilibrium experiments and depends on pH, properties of metal ions, biomass concentration, preliminary physical or chemical treatment of the biomass, presence of various organic and inorganic ions and on temperature. The yeast biomass may be obtained using numerous industrial processes, that decreases considerably the biosorbent cost. Most yeasts can sorb a wide range of metals or be strictly specific in respect of only one metal. Special attention would be paid to the cell wall which structure determines sorption proceeding mechanisms. Problems of mechanisms of heavy metal biosorption by microorganisms at molecular level are discussed. The review also deals with the newest developments on improving the biosorption processes in microorganisms, yeast in particular. PMID:15104060

Podgorski?, V S; Kasatkina, T P; Lozovaia, O G

2004-01-01

254

The one hour yeast proteome.  

PubMed

We describe the comprehensive analysis of the yeast proteome in just over one hour of optimized analysis. We achieve this expedited proteome characterization with improved sample preparation, chromatographic separations, and by using a new Orbitrap hybrid mass spectrometer equipped with a mass filter, a collision cell, a high-field Orbitrap analyzer, and, finally, a dual cell linear ion trap analyzer (Q-OT-qIT, Orbitrap Fusion). This system offers high MS(2) acquisition speed of 20 Hz and detects up to 19 peptide sequences within a single second of operation. Over a 1.3 h chromatographic method, the Q-OT-qIT hybrid collected an average of 13,447 MS(1) and 80,460 MS(2) scans (per run) to produce 43,400 (x) peptide spectral matches and 34,255 (x) peptides with unique amino acid sequences (1% false discovery rate (FDR)). On average, each one hour analysis achieved detection of 3,977 proteins (1% FDR). We conclude that further improvements in mass spectrometer scan rate could render comprehensive analysis of the human proteome within a few hours. PMID:24143002

Hebert, Alexander S; Richards, Alicia L; Bailey, Derek J; Ulbrich, Arne; Coughlin, Emma E; Westphall, Michael S; Coon, Joshua J

2014-01-01

255

Glycogenolytic enzymes in sporulating yeast.  

PubMed Central

During meiosis in Saccharomyces cerevisiae, the polysaccharide glycogen is first synthesized and then degraded during the period of spore maturation. We have detected, in sporulating yeast strains, an enzyme activity which is responsible for the glycogen catabolism. The activity was absent in vegetative cells, appeared coincidently with the beginning of glycogenolysis and the appearance of mature ascospores, and increased progressively until spourlation was complete. The specific activity of glycogenolytic enzymes in the intact ascus was about threefold higher than in isolated spores. The glycogenolysis was not due to combinations of phosphorylase plus phosphatase or amylase plus maltase. Nonsporulating cells exhibited litle or no glycogen catabolism and contained only traces of glycogenolytic enzyme, suggesting that the activity is sporulation specific. The partially purified enzyme preparation degraded amylose and glycogen, releasing glucose as the only low-molecular-weight product. Maltotriose was rapidly hydrolyzed; maltose was less susceptible. Alpha-methyl-D-glucoside, isomaltose, and linear alpha-1,6-linked dextran were not attacked. However, the enzyme hydrolyzed alpha-1,6-glucosyl-Schardinger dextrin and increased the beta-amylolysis of beta-amylase-limit dextrin. Thus, the preparation contains alpha-1,4- and alpha-1,6-glucosidase activities. Sephadex G-150 chromatography partially resolved the enzyme into two activities, one of which may be a glucamylase and the other a debranching enzyme. Images PMID:350852

Colonna, W J; Magee, P T

1978-01-01

256

Boolean Model of Yeast Apoptosis as a Tool to Study Yeast and Human Apoptotic Regulations  

PubMed Central

Programmed cell death (PCD) is an essential cellular mechanism that is evolutionary conserved, mediated through various pathways and acts by integrating different stimuli. Many diseases such as neurodegenerative diseases and cancers are found to be caused by, or associated with, regulations in the cell death pathways. Yeast Saccharomyces cerevisiae, is a unicellular eukaryotic organism that shares with human cells components and pathways of the PCD and is therefore used as a model organism. Boolean modeling is becoming promising approach to capture qualitative behavior and describe essential properties of such complex networks. Here we present large literature-based and to our knowledge first Boolean model that combines pathways leading to apoptosis (a type of PCD) in yeast. Analysis of the yeast model confirmed experimental findings of anti-apoptotic role of Bir1p and pro-apoptotic role of Stm1p and revealed activation of the stress protein kinase Hog proposing the maximal level of activation upon heat stress. In addition we extended the yeast model and created an in silico humanized yeast in which human pro- and anti-apoptotic regulators Bcl-2 family and Valosin-contain protein (VCP) are included in the model. We showed that accumulation of Bax in silico humanized yeast shows apoptotic markers and that VCP is essential target of Akt Signaling. The presented Boolean model provides comprehensive description of yeast apoptosis network behavior. Extended model of humanized yeast gives new insights of how complex human disease like neurodegeneration can initially be tested. PMID:23233838

Kazemzadeh, Laleh; Cvijovic, Marija; Petranovic, Dina

2012-01-01

257

Boolean model of yeast apoptosis as a tool to study yeast and human apoptotic regulations.  

PubMed

Programmed cell death (PCD) is an essential cellular mechanism that is evolutionary conserved, mediated through various pathways and acts by integrating different stimuli. Many diseases such as neurodegenerative diseases and cancers are found to be caused by, or associated with, regulations in the cell death pathways. Yeast Saccharomyces cerevisiae, is a unicellular eukaryotic organism that shares with human cells components and pathways of the PCD and is therefore used as a model organism. Boolean modeling is becoming promising approach to capture qualitative behavior and describe essential properties of such complex networks. Here we present large literature-based and to our knowledge first Boolean model that combines pathways leading to apoptosis (a type of PCD) in yeast. Analysis of the yeast model confirmed experimental findings of anti-apoptotic role of Bir1p and pro-apoptotic role of Stm1p and revealed activation of the stress protein kinase Hog proposing the maximal level of activation upon heat stress. In addition we extended the yeast model and created an in silico humanized yeast in which human pro- and anti-apoptotic regulators Bcl-2 family and Valosin-contain protein (VCP) are included in the model. We showed that accumulation of Bax in silico humanized yeast shows apoptotic markers and that VCP is essential target of Akt Signaling. The presented Boolean model provides comprehensive description of yeast apoptosis network behavior. Extended model of humanized yeast gives new insights of how complex human disease like neurodegeneration can initially be tested. PMID:23233838

Kazemzadeh, Laleh; Cvijovic, Marija; Petranovic, Dina

2012-01-01

258

Inhibition of spoilage yeasts in cheese by killer yeast Williopsis saturnus var. saturnus.  

PubMed

Williopsis saturnus var. saturnus is a known killer toxin-producing yeast. The effects of this yeast as a biopreservative against spoilage yeasts (galactose fermenting) were investigated in cheeses made under laboratory conditions. At an inoculation level of approximately 10(6) CFU/g of cheese, this killer yeast inhibited growth of lactose non-fermenting but galactose-fermenting yeast Saccharomyces cerevisiae VL1 inoculated at approximately 10(3) CFU/g; it also inhibited growth of lactose-fermenting and galactose-fermenting yeast Kluvyveromyces marxianus ATCC8640 inoculated at approximately 10(3)-10(4) CFU/g in the cheeses manufactured with galactose-producing starter culture Streptococcus thermophilus. In contrast, the two spoilage yeasts grew to approximately 10(6) CFU/g from the initial cell count of approximately 10(3) CFU/g without the killer yeast. This study indicated that W. saturnus var. saturnus could be an effective biopreservative for cheese spoilage control. PMID:19349088

Liu, Shao-Quan; Tsao, Marlene

2009-05-31

259

Selection in yeast I: Assessing genetic stability and relative fitness of commercial yeasts  

Microsoft Academic Search

Summary The potential for changes in allele frequencies in yeast populations by selection was examined. Cells from the wine yeastSaccharomyces cerevisiae (strain Montrachet) were grown over a large number of generations using two different culturing techniques, each with two variations: serial transfers on WLN agar plates with and without UV irradiation, and continuous culture in autoclaved and in filter-sterilized grape

Ronald E. Subden; Robert L. Charlebois; C. Kenneth Carey

1987-01-01

260

Thermoregulation during flight: body temperature and sensible heat transfer in free-ranging Brazilian free-tailed bats (Tadarida brasiliensis).  

PubMed

Bat wings are important for thermoregulation, but their role in heat balance during flight is largely unknown. More than 80% of the energy consumed during flight generates heat as a by-product, and thus it is expected that bat wings should dissipate large amounts of heat to prevent hyperthermia. We measured rectal (T(r)) and surface (T(s)) temperatures of Brazilian free-tailed bats (Tadarida brasiliensis) as they emerged from and returned to their daytime roosts and calculated sensible heat transfer for different body regions (head, body, wings, and tail membrane). Bats' T(r) decreased from 36.8°C during emergence flights to 34.4°C during returns, and T(s) scaled positively with ambient temperature (T(a)). Total radiative heat loss from bats was significantly greater for a radiative sink to the night sky than for a sink with temperature equal to T(a). We found that free-ranging Brazilian free-tailed bats, on average, do not dissipate heat from their wings by convection but instead dissipate radiative heat (L) to the cloudless night sky during flight ([Formula: see text] W). However, within the range of T(a) measured in this study, T. brasiliensis experienced net heat loss between evening emergence and return flights. Regional hypothermia reduces heat loss from wings that are exposed to potentially high convective fluxes. Additional research is needed to establish the role of wings in evaporative cooling during flight in bats. PMID:21034204

Reichard, Jonathan D; Fellows, Spenser R; Frank, Alexander J; Kunz, Thomas H

2010-01-01

261

Behavioural evidence of male volatile pheromones in the sex-role reversed wolf spiders Allocosa brasiliensis and Allocosa alticeps  

NASA Astrophysics Data System (ADS)

The use of chemical signals in a sexual context is widespread in the animal kingdom. Most studies in spiders report the use of female pheromones that attract potential sexual partners. Allocosa brasiliensis and Allocosa alticeps are two burrowing wolf spiders that show sex-role reversal. Females locate male burrows and initiate courtship before males perform any detectable visual or vibratory signal. So, females of these species would be detecting chemical or mechanical cues left by males. Our objective was to explore the potential for male pheromones to play a role in mate detection in A. brasiliensis and A. alticeps. We designed two experiments. In Experiment 1, we tested the occurrence of male contact pheromones by evaluating female courtship when exposed to empty burrows constructed by males or females (control). In Experiment 2, we tested the existence of male volatile pheromones by evaluating female behaviour when exposed to artificial burrows connected to tubes containing males, females or empty tubes (control). Our results suggest the occurrence of male volatile pheromones that trigger female courtship in both Allocosa species. The sex-role reversal postulated for these wolf spiders could be driving the consequent reversal in typical pheromone-emitter and detector roles expected for spiders.

Aisenberg, Anita; Baruffaldi, Luciana; González, Macarena

2010-01-01

262

Identification of laticifer-specific genes and their promoter regions from a natural rubber producing plant Hevea brasiliensis.  

PubMed

Latex, the milky cytoplasm of highly differentiated cells called laticifers, from Hevea brasiliensis is a key source of commercial natural rubber production. One way to enhance natural rubber production would be to express genes involved in natural rubber biosynthesis by a laticifer-specific overexpression system. As a first step to identify promoters which could regulate the laticifer-specific expression, we identified random clones from a cDNA library of H. brasiliensis latex, resulting in 4325 expressed sequence tags (ESTs) assembled into 1308 unigenes (692 contigs and 617 singletons). Quantitative analyses of the transcription levels of high redundancy clones in the ESTs revealed genes highly and predominantly expressed in laticifers, such as Rubber Elongation Factor (REF), Small Rubber Particle Protein and putative protease inhibitor proteins. HRT1 and HRT2, cis-prenyltransferases involved in rubber biosynthesis, was also expressed predominantly in laticifers, although these transcript levels were 80-fold lower than that of REF. The 5'-upstream regions of these laticifer-specific genes were cloned and analyzed in silico, revealing seven common motifs consisting of eight bases. Furthermore, transcription factors specifically expressed in laticifers were also identified. The common motifs in the laticifer-specific genes and the laticifer-specific transcription factors are potentially involved in the regulation of gene expression in laticifers. PMID:25017153

Aoki, Yuichi; Takahashi, Seiji; Takayama, Daisuke; Ogata, Yoshiyuki; Sakurai, Nozomu; Suzuki, Hideyuki; Asawatreratanakul, Kasem; Wititsuwannakul, Dhirayos; Wititsuwannakul, Rapepun; Shibata, Daisuke; Koyama, Tanetoshi; Nakayama, Toru

2014-08-01

263

Ants (Hymenoptera: Formicidae) in Vineyards That Are Infested or Uninfested With Eurhizococcus brasiliensis (Hemiptera: Margarodidae) in Southeastern Brazil.  

PubMed

The association between ants and mealybugs can result in damage to agriculture, including vineyards. In southern Brazil, the ant Linepithema micans F. contributes to the dispersal of Eurhizococcus brasiliensis (Wille) (ground pearl), a root mealybug that can lead to economic losses. In this study, the ant communities in vineyards that were infested or uninfested with ground pearls were evaluated in the primary municipalities that produce the Niágara Rosada variety of grapes in southeastern Brazil. The hypothesis of this study was that the composition of the ant community differs between vineyards with and without E. brasiliensis. The ants were collected using subterranean traps in 10 vineyards infested with this mealybug and 10 uninfested vineyards. There was no significant association between ground pearls and the composition or richness of the ant species. Solenopsis invicta (Buren) (Hymenoptera: Formicidae) was the most frequently observed, and Pheidole aberrans (Mayr), Pheidole subarmata (Mayr), and Brachymyrmex incisus F. were common, especially in the rainy season when ground-pearl nymphs were prevalent in the state of São Paulo. Species from preserved or specialized environments were recorded in the vineyards, even with the use of conventional management techniques. PMID:25347833

Munhae, Catarina De Bortoli; Morini, Maria Santina De Castro; Bueno, Odair Correa

2014-01-01

264

Induction of peroxidase, scopoletin, phenolic compounds and resistance in Hevea brasiliensis by elicitin and a novel protein elicitor purified from Phytophthora palmivora  

Microsoft Academic Search

Elicitin and a new protein 75kDa elicitor were purified from the culture filtrate of Phytophthora palmivora, a pathogen of Hevea brasiliensis (rubber plant). Elicitin was obtained by using a one step of DEAE cellulose chromatography and the new elicitor was obtained by two steps of chromatography: a DEAE cellulose column followed by a hydrophobic column. Both elicitors were stable to

Chinnapun Dutsadee; Churngchow Nunta

2008-01-01

265

Effect of tapping activity on the dynamics of radial growth of Hevea brasiliensis trees.  

PubMed

Rubber tree (Hevea brasiliensis Müll. Arg.) radial growth dynamics were monitored with displacement sensors, together with latex production, to investigate three aspects of the dual production of latex and wood: (1) the usefulness of fine-scale dendrometric measurements as a physiological tool to detect water shortage through radial growth; (2) the dynamic aspects, both at the seasonal and at the multi-year scale, of the competition between latex and wood production; and (3) the spatial distribution of radial growth rates around the tapping cut. Radial growth of untapped control trees started with the onset of the rainy season and lasted until the onset of the dry season, ceasing completely during the driest period. Displacement sensors provided a sensitive means of detecting water shortage, with a clear correlation between diameter variations and changes in water availability (both daily evapotranspiration and monthly rainfall) over the whole annual cycle. However, the correlation was significantly disturbed in tapped trees. After resumption of tapping, the radial growth rate dropped sharply within two weeks and the effect persisted throughout the whole season, so that the cumulative growth of tapped trees was about half that of untapped trees, with the cumulative growth deficit reaching 80% for the period from mid-June to November. This long-known negative impact of tapping on growth was much stronger in the second year of tapping than in the first, whereas latex production increased significantly between the first and second year of tapping. The increased latex production, which could not be ascribed to climatic conditions, shows that the establishment of an artificial latex sink is a progressive, long-term process likely involving many aspects of metabolism. As expected, ethylene significantly increased latex production in both years; however, ethylene had no effect on the growth rates of tapped trees. Radial growth was differentially affected at different locations around the tapping cut, with growth rates significantly lower in the tapped panel than in the untapped panel, and higher above the cut than below the cut. Thus, caution is needed when deriving whole stem wood production from girth measurements at one location on the stem, especially from girth measurements made close to the tapping cut. This also provides new evidence for the location of the latex regeneration area in the tapped panel, below the cut. PMID:17169897

Silpi, Unakorn; Thaler, Philippe; Kasemsap, Poonpipope; Lacointe, André; Chantuma, Arak; Adam, Boris; Gohet, Eric; Thaniswanyankura, Sornprach; Améglio, Thierry

2006-12-01

266

Mitochondrial membrane lipidome defines yeast longevity.  

PubMed

Our studies revealed that lithocholic acid (LCA), a bile acid, is a potent anti-aging natural compound that in yeast cultured under longevity-extending caloric restriction (CR) conditions acts in synergy with CR to enable a significant further increase in chronological lifespan. Here, we investigate a mechanism underlying this robust longevity-extending effect of LCA under CR. We found that exogenously added LCA enters yeast cells, is sorted to mitochondria, resides mainly in the inner mitochondrial membrane, and also associates with the outer mitochondrial membrane. LCA elicits an age-related remodeling of glycerophospholipid synthesis and movement within both mitochondrial membranes, thereby causing substantial changes in mitochondrial membrane lipidome and triggering major changes in mitochondrial size, number and morphology. In synergy, these changes in the membrane lipidome and morphology of mitochondria alter the age-related chronology of mitochondrial respiration, membrane potential, ATP synthesis and reactive oxygen species homeostasis. The LCA-driven alterations in the age-related dynamics of these vital mitochondrial processes extend yeast longevity. In sum, our findings suggest a mechanism underlying the ability of LCA to delay chronological aging in yeast by accumulating in both mitochondrial membranes and altering their glycerophospholipid compositions. We concluded that mitochondrial membrane lipidome plays an essential role in defining yeast longevity. PMID:23924582

Beach, Adam; Richard, Vincent R; Leonov, Anna; Burstein, Michelle T; Bourque, Simon D; Koupaki, Olivia; Juneau, Mylène; Feldman, Rachel; Iouk, Tatiana; Titorenko, Vladimir I

2013-07-01

267

A study of ethanol tolerance in yeast.  

PubMed

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

1990-01-01

268

Influence of pesticides on yeasts colonizing leaves.  

PubMed

The effect of nine different pesticides on the growth of yeasts isolated from the leaves of fruit and forest trees was investigated. Four insecticides (with the active ingredients: thiacloprid, deltamethrin, lambdacyhalothrin, and thiamethoxam) and five fungicides (with the effective substances: bitertanol, kresoxim-methyl, mancozeb, trifloxystrobin, and cupric oxychloride) were tested. The concentrations of chemicals were those recommended by the manufacturers for the spraying of trees. The yeast strains isolated from the leaves of fruit trees were not sensitive to any of the insecticides. The majority of yeast strains isolated from the leaves of forest trees were either not sensitive or only to a small extent. While Rhodotorula mucilaginosa and Pichia anomala were not affected by any insecticide, the strains of Cryptococcus laurentii and Rhodotorula glutinis showed the highest sensitivity. The effects of fungicides on the growth of isolated yeasts were more substantial. The fungicide Dithane DG (mancozeb) completely inhibited the growth of all yeasts. All strains isolated from fruit tree leaves were more resistant to the tested fungicides than those isolated from the leaves of forest trees. The most resistant strains from the leaves of fruit trees belonged to the species Metschnikowia pulcherrima, Pichia anomala, and Saccharomyces cerevisiae, whereas Cryptococcus albidus and C. laurentii, originating from the leaves of forest trees, showed the highest sensitivity to fungicides. PMID:22351984

Vadkertiová, Renata; Sláviková, Elena

2011-01-01

269

Ecology of pathogenic yeasts in Amazonian soil.  

PubMed Central

In an investigation of Amazonian soil as a natural reservoir for pathogenic fungi, 1,949 soil samples collected from diverse geographical and ecological settings of the Brazilian Amazon Basin were analyzed for the presence of non-keratinophilic fungi by the indirect mouse inoculation procedure and for the presence of keratinophilic fungi by the hair bait technique. All soil samples were acidic with low pH values. From 12% of the soil samples, 241 yeast and yeastlike isolates pertaining to six genera and 82 species were recovered, of which 63% were Torulopsis and 26% were Candida species. Nine fungi with known pathogenic potentials were encountered among 43% (104) of the isolates: T. glabrata, C. guilliermondii, C. albicans, C. pseudotropicalis, C. stellatoidea, C. tropicalis, Rhodotorula rubra, and Wangiella dermatitidis. The yeast flora was marked by species diversity, low frequency of each species, random geographical distribution, and an apparent lack of species clustering. The composition and distribution of the yeast flora in soil differed from those of the yeast flora harbored by bats, suggesting that the Amazonian external environment and internal bat organs act as independent natural habitats for yeasts. PMID:6538774

Mok, W Y; Luizao, R C; do Socorro Barreto da Silva, M; Teixeira, M F; Muniz, E G

1984-01-01

270

The organization of oligonucleosomes in yeast.  

PubMed Central

We have developed a method of preparing yeast chromatin that facilitates the analysis of nucleoprotein organization. Yeast chromatin, isolated as an insoluble complex, is digested with micrococcal nuclease and fractionated into major insoluble and soluble fractions. No nucleosomal repeat is seen early in digestion for the insoluble fraction. Nucleosomal complexes of the soluble fraction are excised by nuclease in a distinctive non-random pattern; they are markedly depleted in mononucleosomes. When we analyze the soluble material by high resolution native electrophoresis, we find that the nucleoproteins resolve into two bands for each DNA multimer of the nucleosomal repeat. Our results suggest that there are structural similarities between bulk yeast chromatin and chromatin configurations found in transcribing genes of complex eukaryotes. Images PMID:6344013

Szent-Gyorgyi, C; Isenberg, I

1983-01-01

271

Biofuels. Altered sterol composition renders yeast thermotolerant.  

PubMed

Ethanol production for use as a biofuel is mainly achieved through simultaneous saccharification and fermentation by yeast. Operating at ?40°C would be beneficial in terms of increasing efficiency of the process and reducing costs, but yeast does not grow efficiently at those temperatures. We used adaptive laboratory evolution to select yeast strains with improved growth and ethanol production at ?40°C. Sequencing of the whole genome, genome-wide gene expression, and metabolic-flux analyses revealed a change in sterol composition, from ergosterol to fecosterol, caused by mutations in the C-5 sterol desaturase gene, and increased expression of genes involved in sterol biosynthesis. Additionally, large chromosome III rearrangements and mutations in genes associated with DNA damage and respiration were found, but contributed less to the thermotolerant phenotype. PMID:25278608

Caspeta, Luis; Chen, Yun; Ghiaci, Payam; Feizi, Amir; Buskov, Steen; Hallström, Björn M; Petranovic, Dina; Nielsen, Jens

2014-10-01

272

Cytotoxic Mechanism of Selenomethionine in Yeast*  

PubMed Central

Although selenium is an essential element, its excessive uptake is detrimental to living organisms. The significance of selenium for living organisms has been exploited for various purposes. However, the molecular basis of selenium toxicity is not completely understood. Here, we applied a capillary electrophoresis time-of-flight mass spectrometry-based metabolomics approach to analysis of yeast cells treated with selenomethionine. The data indicated that intracellular thiol compounds are significantly decreased, and diselenide and selenosulfide compounds are increased in selenomethionine-treated cells. The growth defect induced by selenomethionine was recovered by extracellular addition of cysteine and by genetic modification of yeast cells that have an additional de novo synthetic pathway for cysteine. Because cysteine is an intermediate of thiol compounds, these results suggested that the loss of a reduced form of thiol compounds due to selenomethionine causes a growth defect of yeast cells. PMID:22311978

Kitajima, Toshihiko; Jigami, Yoshifumi; Chiba, Yasunori

2012-01-01

273

[Molecular taxonomy techniques used for yeast identification].  

PubMed

Due to the major impact of yeasts in human life based on the existence of pathogen yeast species and of species with biotechnological abilities, in the last few years new molecular techniques are performed for an accurate identification of natural isolates. Our study is aimed to review some of these techniques such as electrokariotyping by PFGE (Pulsed Field Gel Electrophoresis), estimation of the molar percentage of guanine and cytosine, the applications of PCR reaction in yeast identification using RAPD (Random amplified polymorphic DNA), UP-PCR (Universally Primed Polymerase Chain Reaction), MLST (Multilocus sequence typing) techniques, mtDNA and rDNA homology studies. Such molecular techniques complete the phenotypical characterization based on classical taxonomical tests allowing thus the polyphasic identification of the microorganisms. PMID:16938931

Ghindea, Raluca; Csutak, Ortansa; Stoica, Ileana; Ionescu, Robertina; Soare, Simona; Pelinescu, Diana; Nohit, Ana-Maria; Creang?, Oana; Vassu, Tatiana

2004-01-01

274

Metabolic cycling without cell division cycling in respiring yeast  

E-print Network

Despite rapid progress in characterizing the yeast metabolic cycle, its connection to the cell division cycle (CDC) has remained unclear. We discovered that a prototrophic batch culture of budding yeast, growing in a ...

Slavov, Nikolai G.

275

21 CFR 172.381 - Vitamin D2 bakers yeast.  

...prescribed conditions: (a) Vitamin D2 bakers yeast is the substance produced by exposing bakers yeast (Saccharomyces cerevisiae ) to ultraviolet light, resulting in the photochemical conversion of endogenous ergosterol in bakers...

2014-04-01

276

Original article Chromium yeast affects growth performance but not  

E-print Network

Original article Chromium yeast affects growth performance but not whole carcass composition the effects of supplemented trivalent chromium (Cr) from chromium yeast on growth performance, carcass vs. ad libitum in other reported experiments). (© Elsevier / Inra) chromium / pig / carcass

Paris-Sud XI, Université de

277

RESEARCH ARTICLE Open Access Histone modification pattern evolution after yeast  

E-print Network

RESEARCH ARTICLE Open Access Histone modification pattern evolution after yeast gene duplication for evolutionary innovations. Many studies evidenced that genetic regulatory network evolved rapidly shortly after gene duplication. In this study, we conducted detailed analyses on yeast histone modification (HM

Gu, Xun

278

[The yeast biofilm in human medicine].  

PubMed

In recent years, the role of Candida yeasts as causative agents of nosocomial infections has increased. One of the important virulence factors contributing to the development of such infections is biofilm production. This virulence factor enables yeast to colonize both native surfaces and artificial implants. The most common sources of infection are patients themselves, in particular the gastrointestinal tract and skin. The vectors of exogenous yeast infections are predominantly the hands of the health personnel and contaminated medical instruments. The adhesion of yeasts to the implant surfaces is determined both by implant surface and yeast characteristics. This is followed by proliferation and production of microcolonies and extracellular matrix. The final biofilm structure is also influenced by the production of hyphae and pseudohyphae. The entire process of biofilm production is controlled by numerous regulatory systems, with the key role being played by the quorum sensing system. Like the adhered bacterial cultures, candidas growing in the form of a biofilm are highly resistant to antimicrobial therapy. Resistance of yeast biofilms to antifungals is a complex process with multiple contributing factors. These are especially increased gene expression (e.g. genes encoding the so called multidrug efflux pumps), limited penetration of substances through the extracellular matrix, inhibited cell growth and altered microenvironment in deeper biofilm layers. The concentrations of antifungals able to effectively affect the biofilm cells exceed, by several orders of magnitude, the values of conventionally determined MICs. High biofilm resistance results in ineffective antifungal therapy of biofilm infections. Therefore, if possible, the colonized implant should be removed. Conservative therapy should involve antifungals with a proven effect on the biofilm (e.g. caspofungin). The most effective measure in fighting biofilm infections is prevention, especially adhering to aseptic techniques when manipulating with implants and their correct maintenance. PMID:17929219

R?zicka, Filip; Holá, Veronika; Votava, Miroslav

2007-08-01

279

[Effect of stress on the composition of yeast lipids].  

PubMed

Pigmented (Rhodotorula glutinis) and nonpigmented (Lipomyces starkeyi) yeasts were studied. Exogenous stressors (UV irradiation and methylene blue) were shown to change the composition of yeast lipids (especially the ratio of unsaturated fatty acids) and to increase the content of lipid peroxidation products formed (particularly in nonpigmented yeasts). In carotene-synthesizing yeasts, these stressors decreased the amount of carotenoids produced and did not affect the ratio between carotenoid pigments (beta-carotene, torulene, and torularhodin). PMID:10752082

Zalashko, M V; Salokhina, G A; Koroleva, I F

2000-01-01

280

[Growth of epiphytic and soil yeasts on wheat seedlings].  

PubMed

Colonization of wheat seedlings by epiphytic (Rhodotorula glutinis) and soil (Lipomyces starkeyi) yeasts was studied by scanning electron microscopy. Epiphytic yeast cells dominated on the plant surface. Soil yeast cells were randomly distributed among both the zones of a seedling and the particles of an inorganic substrate. It has been found that epiphytic yeast strains can readily grow on the surface of a plant. PMID:561879

Guzeva, I S; Guzev, V S; Bab'eva, I P; Zviagintsev, D G

1977-01-01

281

Effects of stress on the composition of yeast lipids  

Microsoft Academic Search

Pigmented(Rhodotorula glutinis) and nonpigmented(Lipomyces starkeyi) yeasts were studied. Exogenous Stressors (UV irradiation and methylene blue) were shown to change the composition of yeast\\u000a lipids (especially the ratio of unsaturated fatty acids) and to increase the content of lipid peroxidation products formed\\u000a (particularly in nonpigmented yeasts). In carotene-synthesizing yeasts, these Stressors decreased the amount of carotenoids\\u000a produced and did not affect

M. V. Zalashko; G. A. Salokhina; I. F. Koroleva

2000-01-01

282

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

PubMed

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 constitutively expressed under the ADH1 promoter. The growth, substrate utilization and fermentative capacity of this organism are described. PMID:11470369

Marín, D; Jiménez, A; Fernández Lobato, M

2001-07-24

283

Mitochondrial network size scaling in budding yeast.  

PubMed

Mitochondria must grow with the growing cell to ensure proper cellular physiology and inheritance upon division. We measured the physical size of mitochondrial networks in budding yeast and found that mitochondrial network size increased with increasing cell size and that this scaling relation occurred primarily in the bud. The mitochondria-to-cell size ratio continually decreased in aging mothers over successive generations. However, regardless of the mother's age or mitochondrial content, all buds attained the same average ratio. Thus, yeast populations achieve a stable scaling relation between mitochondrial content and cell size despite asymmetry in inheritance. PMID:23139336

Rafelski, Susanne M; Viana, Matheus P; Zhang, Yi; Chan, Yee-Hung M; Thorn, Kurt S; Yam, Phoebe; Fung, Jennifer C; Li, Hao; Costa, Luciano da F; Marshall, Wallace F

2012-11-01

284

Mitochondrial Network Size Scaling in Budding Yeast**  

PubMed Central

Mitochondria must grow with the growing cell to ensure proper cellular physiology and inheritance upon division. We measured the physical size of mitochondrial networks in budding yeast and found that mitochondrial network size increased with increasing cell size and that this scaling relation occurred primarily in the bud. The mitochondria to cell size ratio continually decreased in aging mothers over successive generations. However, regardless of mother age or mitochondrial content, all buds attained the same average ratio. Thus, yeast populations achieve a stable scaling relation between mitochondrial content and cell size despite asymmetry in inheritance. PMID:23139336

Rafelski, Susanne M.; Viana, Matheus P.; Zhang, Yi; Chan, Yee-Hung M.; Thorn, Kurt S.; Yam, Phoebe; Fung, Jennifer C.; Li, Hao; Costa, Luciano da F.; Marshall, Wallace F.

2013-01-01

285

Principles of chromosomal organization: lessons from yeast  

PubMed Central

The spatial organization of genes and chromosomes plays an important role in the regulation of several DNA processes. However, the principles and forces underlying this nonrandom organization are mostly unknown. Despite its small dimension, and thanks to new imaging and biochemical techniques, studies of the budding yeast nucleus have led to significant insights into chromosome arrangement and dynamics. The dynamic organization of the yeast genome during interphase argues for both the physical properties of the chromatin fiber and specific molecular interactions as drivers of nuclear order. PMID:21383075

Zimmer, Christophe

2011-01-01

286

Yeast identification in floral nectar of Mimulus aurantiacus (Invited)  

Microsoft Academic Search

Nectar is such a sugar-rich resource that serves as a natural habitat in which microbes thrive. As a result, yeasts arrive to nectar on the bodies of pollinators such as hummingbirds and bees. Yeasts use the sugar in nectar for their own needs when introduced. This research focuses on the identification of different types of yeast that are found in

C. Kyauk; M. Belisle; T. Fukami

2009-01-01

287

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...

2014-04-01

288

Boolean Network Model Predicts Cell Cycle Sequence of Fission Yeast  

E-print Network

Boolean Network Model Predicts Cell Cycle Sequence of Fission Yeast Maria I. Davidich, Stefan network model of the cell-cycle regulatory network of fission yeast (Schizosaccharomyces Pombe sequence being a strongly attractive trajectory. Comparing the fission yeast cell-cycle model to a similar

Bornholdt, Stefan

289

Research Focus A short history of recombination in yeast  

E-print Network

Research Focus A short history of recombination in yeast Clifford W. Zeyl1* and Sarah P. Otto2* 1 of fungal genomics, we know little about either the ecology or reproductive biology of the budding yeast of a studyofhistoricalpoutcrossingeventsand inferthe genomic positions of previous recombination events in the yeast Saccharomyces cerevisiae

Otto, Sarah

290

Robust Spatial Sensing of Mating Pheromone Gradients by Yeast Cells  

E-print Network

Robust Spatial Sensing of Mating Pheromone Gradients by Yeast Cells Travis I. Moore1,2 , Ching not degrade the pheromone input. The yeast cells exhibited good accuracy with the mating projection typically caused defects in both sensing and response. Interestingly, yeast cells employed adaptive mechanisms

Nie, Qing

291

Clustering, Communication and Environmental Oscillations in Populations of Budding Yeast  

E-print Network

Clustering, Communication and Environmental Oscillations in Populations of Budding Yeast Chris describe how simple models of communication, consistent with known yeast phys- iological mechanisms relevant variables during yeast growth and division have been reported and studied for over 40 years [8, 12

Young, Todd

292

Yeast Genes That Enhance the Toxicity of a Mutant Huntingtin  

E-print Network

Yeast Genes That Enhance the Toxicity of a Mutant Huntingtin Fragment or -Synuclein Stephen-wide screens were performed in yeast to identify genes that enhance the toxicity of a mutant huntingtin's yeast Sac- charomyces cerevisiae as a model eukaryotic organism to test the hypothesis that the down

Lindquist, Susan

293

Exploring the Yeast Genome with Generalized Singular Value  

E-print Network

Exploring the Yeast Genome with Generalized Singular Value Decomposition Andrew Ferguson Advisor courses of the yeast Saccharomyces cerevisiae under two different experimental con- ditions. In the first analysis, a comparison is performed between the yeast stress response to hydrogen peroxide (H2O2

Fonseca, Rodrigo

294

INVESTIGATION Natural Variation in the Yeast Glucose-Signaling  

E-print Network

of respiration, is a hallmark of budding yeast's glucose response and a model for the Warburg effect in humanINVESTIGATION Natural Variation in the Yeast Glucose-Signaling Network Reveals a New Role uncovered, despite numerous investigations of laboratory yeast strains. Here we studied a wild isolate

Gasch, Audrey P.

295

Global Gene Expression Analysis of Yeast Cells during Sake Brewing  

Microsoft Academic Search

During the process of brewing Japanese sake, rice starch is saccharified by enzymes produced by koji (Aspergillus oryzae), and the resultant glucose is fermented to ethanol by sake yeast (Saccharomyces cerevisiae). This process allows a highly con- densed mash to be made without accumulation of high levels of sugars, which inhibit yeast cell growth and ethanol fermenta- tion. Thus, yeast

Hong Wu; Xiaohong Zheng; Yoshio Araki; Hiroshi Sahara; Hiroshi Takagi; Hitoshi Shimoi

2006-01-01

296

New insights into treating Parkinson's from yeast, stem cell experiments  

E-print Network

problems of Parkinson's disease may seem tenuous at best, the researchers engineered the yeast for compounds that were able to reverse the problems when administered to the yeast. A number of compounds@globe.com. Follow her on Twitter @carolynyjohnson. New insights into treating Parkinson's from yeast, stem cell exp

Sabatini, David M.

297

Gene Expression in Yeast. Helsinki 1983, ed. by M.  

E-print Network

of the Alko Yeast Symposium Korhola & E. Viiisiinen, Foundation for Fermentation Research I (1983): 19Gene Expression in Yeast. Helsinki 1983, ed. by M. Biotechnical and Industrial Proceedings-29. A RELATIONSHIP BETI^IEENCHROMATIN STRUCTUREAND GENETIC ELEMENTS AT THE YEAST HIS3 LOCUS Department of Biological

298

Production of lipid compounds in the yeast Saccharomyces cerevisiae  

Microsoft Academic Search

This review describes progress using the yeast Saccharomyces cerevisiae as a model organism for the fast and efficient analysis of genes and enzyme activities involved in the lipid biosynthetic pathways of several donor organisms. Furthermore, we assess the impact of baker's yeast on the production of novel, high-value lipid compounds. Yeast can be genetically modified to produce selected substances in

M. Veen; C. Lang

2004-01-01

299

Inactivation of platelet-activating factor by a putative acetylhydrolase from the gastrointestinal nematode parasite Nippostrongylus brasiliensis.  

PubMed Central

The adult stage of Nippostrongylus brasiliensis, a strongyloid parasite of the gastrointestinal tract of rats, released a product during in vitro culture which functionally inhibited platelet-activating factor (PAF), measured by its ability to mediate platelet aggregation. The extent of inhibition was proportional to the concentration of excretory/secretory (ES) products and the duration of preincubation with PAF prior to the assay of biological activity. The inhibitory activity was heat labile and was specific for PAF, as incubation of ES products with thrombin showed no diminution of platelet aggregation. Experiments using radiolabelled preparations of PAF demonstrated that the acetyl group esterified at the sn-2 position of the glycerol backbone was liberated on incubation with ES products, indicative of an acetylhydrolase activity. This activity was susceptible to inhibition by DFP, partial inhibition by eserine, but was resistant to PMSF and TPCK at concentrations which inhibit serine proteases. PMID:1537601

Blackburn, C C; Selkirk, M E

1992-01-01

300

In-depth exploration of Hevea brasiliensis latex proteome and "hidden allergens" via combinatorial peptide ligand libraries.  

PubMed

The proteome of Hevea brasiliensis latex has been explored in depth via combinatorial peptide ligand libraries. A total of 300 unique gene products have been identified in this latex, whose proteome has been largely unknown up to the present. In search for unknown allergens, control latex and eluates from the ligand libraries have been fractionated by two-dimensional mapping, blotted and confronted with sera of 18 patients. In addition to the already known and named Hevea major allergens, we have unambiguously detected several others like, for instance: heat shock protein (81 kDa), proteasome subunit (30 kDa), protease inhibitor (8 kDa), hevamine A (43 kDa) and glyceraldehyde-3-phosphate dehydrogenase (37 kDa). Gene Ontology analysis of analyzed fractions has shown that major functions are substantially unchanged after sample treatment, while novel biological functions appeared that were undetectable in the crude sample. PMID:20226888

D'Amato, Alfonsina; Bachi, Angela; Fasoli, Elisa; Boschetti, Egisto; Peltre, Gabriel; Sénéchal, Hélène; Sutra, Jean Pierre; Citterio, Attilio; Righetti, Pier Giorgio

2010-05-01

301

Electrospray ionization mass spectrometry, circular dichroism and SAXS studies of the (S)-hydroxynitrile lyase from Hevea brasiliensis.  

PubMed

We report on experiments pertaining to solution properties of the (S)-hydroxynitrile lyase from Hevea brasiliensis (HbHNL). Small angle X-ray scattering unequivocally established the enzyme to occur in solution as a dimer, presumably of the same structure as in the crystal. The acid induced, irreversible deactivation of HbHNL was examined by electrospray ionization mass spectrometry (ESI-MS), circular dichroism (CD) and by measuring the enzyme activity. The deactivation is paralleled by an unfolding of the enzyme. ESI-MS of this 30000 Da per monomer heavy protein demonstrated that unfolding took place in several stages which are paralleled by a decrease in enzyme activity. Unfolding can also be observed by CD spectroscopy, and there is a clear correlation between enzyme activity and unfolding as detected by ESI-MS and CD. PMID:11341923

Hanefeld, U; Stranzl, G; Straathof, A J; Heijnen, J J; Bergmann, A; Mittelbach, R; Glatter, O; Kratky, C

2001-01-12

302

Schizosaccharomyces japonicus: the fission yeast is a fusion of yeast and hyphae.  

PubMed

The clade of Schizosaccharomyces includes 4 species: S. pombe, S. octosporus, S. cryophilus, and S. japonicus. Although all 4 species exhibit unicellular growth with a binary fission mode of cell division, S. japonicus alone is dimorphic yeast, which can transit from unicellular yeast to long filamentous hyphae. Recently it was found that the hyphal cells response to light and then synchronously activate cytokinesis of hyphae. In addition to hyphal growth, S. japonicas has many properties that aren't shared with other fission yeast. Mitosis of S. japonicas is referred to as semi-open mitosis because dynamics of nuclear membrane is an intermediate mode between open mitosis and closed mitosis. Novel genetic tools and the whole genomic sequencing of S. japonicas now provide us with an opportunity for revealing unique characters of the dimorphic yeast. PMID:24375690

Niki, Hironori

2014-03-01

303

Dynamic changes in brewing yeast cells in culture revealed by statistical analyses of yeast morphological data.  

PubMed

The vitality of brewing yeasts has been used to monitor their physiological state during fermentation. To investigate the fermentation process, we used the image processing software, CalMorph, which generates morphological data on yeast mother cells and bud shape, nuclear shape and location, and actin distribution. We found that 248 parameters changed significantly during fermentation. Successive use of principal component analysis (PCA) revealed several important features of yeast, providing insight into the dynamic changes in the yeast population. First, PCA indicated that much of the observed variability in the experiment was summarized in just two components: a change with a peak and a change over time. Second, PCA indicated the independent and important morphological features responsible for dynamic changes: budding ratio, nucleus position, neck position, and actin organization. Thus, the large amount of data provided by imaging analysis can be used to monitor the fermentation processes involved in beer and bioethanol production. PMID:24012106

Ohnuki, Shinsuke; Enomoto, Kenichi; Yoshimoto, Hiroyuki; Ohya, Yoshikazu

2014-03-01

304

In vivo anti-herpes simplex virus activity of a sulfated derivative of Agaricus brasiliensis mycelial polysaccharide.  

PubMed

Agaricus brasiliensis (syn. A. subrufescens), a basidiomycete fungus native to the Atlantic forest in Brazil, contains cell walls rich in glucomannan polysaccharides. The ?-(1 ? 2)-gluco-?-(1 ? 3)-mannan was isolated from A. brasiliensis mycelium, chemically modified by sulfation, and named MI-S. MI-S has multiple mechanisms of action, including inhibition of herpes simplex virus (HSV) attachment, entry, and cell-to-cell spread (F. T. G. S. Cardozo, C. M. Camelini, A. Mascarello, M. J. Rossi, R. J. Nunes, C. R. Barardi, M. M. de Mendonça, and C. M. O. Simões, Antiviral Res. 92:108-114, 2011). The antiherpetic efficacy of MI-S was assessed in murine ocular, cutaneous, and genital infection models of HSV. Groups of 10 mice were infected with HSV-1 (strain KOS) or HSV-2 (strain 333). MI-S was given either topically or by oral gavage under various pre- and posttreatment regimens, and the severity of disease and viral titers in ocular and vaginal samples were determined. No toxicity was observed in the uninfected groups treated with MI-S. The topical and oral treatments with MI-S were not effective in reducing ocular disease. Topical application of MI-S on skin lesions was also not effective, but cutaneously infected mice treated orally with MI-S had significantly reduced disease scores (P < 0.05) after day 9, suggesting that healing was accelerated. Vaginal administration of MI-S 20 min before viral challenge reduced the mean disease scores on days 5 to 9 (P < 0.05), viral titers on day 1 (P < 0.05), and mortality (P < 0.0001) in comparison to the control groups (untreated and vehicle treated). These results show that MI-S may be useful as an oral agent to reduce the severity of HSV cutaneous and mucosal lesions and, more importantly, as a microbicide to block sexual transmission of HSV-2 genital infections. PMID:23507287

Cardozo, F T G S; Larsen, I V; Carballo, E V; Jose, G; Stern, R A; Brummel, R C; Camelini, C M; Rossi, M J; Simões, C M O; Brandt, C R

2013-06-01

305

In Vivo Anti-Herpes Simplex Virus Activity of a Sulfated Derivative of Agaricus brasiliensis Mycelial Polysaccharide  

PubMed Central

Agaricus brasiliensis (syn. A. subrufescens), a basidiomycete fungus native to the Atlantic forest in Brazil, contains cell walls rich in glucomannan polysaccharides. The ?-(1?2)-gluco-?-(1?3)-mannan was isolated from A. brasiliensis mycelium, chemically modified by sulfation, and named MI-S. MI-S has multiple mechanisms of action, including inhibition of herpes simplex virus (HSV) attachment, entry, and cell-to-cell spread (F. T. G. S. Cardozo, C. M. Camelini, A. Mascarello, M. J. Rossi, R. J. Nunes, C. R. Barardi, M. M. de Mendonça, and C. M. O. Simões, Antiviral Res. 92:108–114, 2011). The antiherpetic efficacy of MI-S was assessed in murine ocular, cutaneous, and genital infection models of HSV. Groups of 10 mice were infected with HSV-1 (strain KOS) or HSV-2 (strain 333). MI-S was given either topically or by oral gavage under various pre- and posttreatment regimens, and the severity of disease and viral titers in ocular and vaginal samples were determined. No toxicity was observed in the uninfected groups treated with MI-S. The topical and oral treatments with MI-S were not effective in reducing ocular disease. Topical application of MI-S on skin lesions was also not effective, but cutaneously infected mice treated orally with MI-S had significantly reduced disease scores (P < 0.05) after day 9, suggesting that healing was accelerated. Vaginal administration of MI-S 20 min before viral challenge reduced the mean disease scores on days 5 to 9 (P < 0.05), viral titers on day 1 (P < 0.05), and mortality (P < 0.0001) in comparison to the control groups (untreated and vehicle treated). These results show that MI-S may be useful as an oral agent to reduce the severity of HSV cutaneous and mucosal lesions and, more importantly, as a microbicide to block sexual transmission of HSV-2 genital infections. PMID:23507287

Cardozo, F. T. G. S.; Larsen, I. V.; Carballo, E. V.; Jose, G.; Stern, R. A.; Brummel, R. C.; Camelini, C. M.; Rossi, M. J.; Simoes, C. M. O.

2013-01-01

306

Distribution of 2-[125I]iodomelatonin Binding in the Brain of Mexican Free-Tailed Bats (Tadarida brasiliensis)  

PubMed Central

The neurohormone melatonin is an important signal for both time of day and time of year in many seasonally breeding animals. High densities of melatonin receptors have been found in the suprachiasmatic nucleus, median eminence, and the pituitary gland in almost all mammals investigated so far, and lower densities of melatonin receptors have also been localized to other brain regions varying in a species-specific fashion. Because species-specific differences in receptor distributions have been correlated with differences in behavior and ecology, a comparative study of how melatonin receptors are distributed in vertebrate brains can be useful to the understanding of the functional organization of neural circuits controlling daily and seasonal behaviors. In this study, we localized and characterized melatonin binding sites in the brain of the Mexican free-tailed bat (Tadarida brasiliensis) using in vitro autoradiography with 2-[125I]iodomelatonin. Tadarida brasiliensis is a nocturnal insectivorous mammal that seasonally migrates, reproduces once a year, and exhibits documented sexual dimorphisms in seasonal reproductive behaviors, most notably in courtship vocalizations. Prominent 2-[125I]iodomelatonin binding was found in the median eminence, suprachiasmatic nuclei, and hippocampus, similar to that observed in other mammals. High densities of binding were also localized to structures of the basal ganglia, including the caudate nucleus, putamen, and nucleus accumbens, a feature commonly observed in songbirds but not in mammals. Saturation analysis indicated that the observed binding sites had an affinity for melatonin typical of the binding properties for the Mel1a receptor subtype. We conclude that melatonin receptor distributions in the Mexican free-tailed bat brain appear to show similarities with the reproductive and circadian systems of other mammals and the basal ganglia of songbirds. PMID:19223684

Schwartz, Christine; Bartell, Paul; Cassone, Vincent; Smotherman, Michael

2010-01-01

307

Yeast Genomic DNA Prep Sterile distilled water  

E-print Network

Auble Lab Yeast Genomic DNA Prep Reagents: Sterile distilled water -mercaptoethanol Sorbitol Buffer conical tube at 3,000 rpms for 5 minutes. 3. Resuspend in 10 ml of sterile distilled (SD) water, then spin for 5 minutes at 3,000 rpms and decant off water. 4. Resuspend in 5 ml of SD water and add 100 µl

Auble, David

308

Carbon source dependent promoters in yeasts.  

PubMed

Budding yeasts are important expression hosts for the production of recombinant proteins.The choice of the right promoter is a crucial point for efficient gene expression, as most regulations take place at the transcriptional level. A wide and constantly increasing range of inducible, derepressed and constitutive promoters have been applied for gene expression in yeasts in the past; their different behaviours were a reflection of the different needs of individual processes.Within this review we summarize the majority of the large available set of carbon source dependent promoters for protein expression in yeasts, either induced or derepressed by the particular carbon source provided. We examined the most common derepressed promoters for Saccharomyces cerevisiae and other yeasts, and described carbon source inducible promoters and promoters induced by non-sugar carbon sources. A special focus is given to promoters that are activated as soon as glucose is depleted, since such promoters can be very effective and offer an uncomplicated and scalable cultivation procedure. PMID:24401081

Weinhandl, Katrin; Winkler, Margit; Glieder, Anton; Camattari, Andrea

2014-01-01

309

Cellular functions of cardiolipin in yeast  

Microsoft Academic Search

Cardiolipin (CL), the signature lipid of mitochondria, plays a critical role in mitochondrial function and biogenesis. The availability of yeast mutants blocked in CL synthesis has facilitated studies of the biological role of this lipid. Perturbation of CL synthesis leads to growth defects not only during respiratory growth but also under conditions in which respiration is not essential. CL was

Amit S. Joshi; Jingming Zhou; Vishal M. Gohil; Shuliang Chen; Miriam L. Greenberg

2009-01-01

310

6 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 relative simplicity of a single celled eukaryotic organism that enables the combination and integration of genetic, biochemical, physico-chemical, cell biological,

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

311

Yeast Idiosyncrasies From Cora Styles (Fink Lab)  

E-print Network

1 Yeast Idiosyncrasies From Cora Styles (Fink Lab) ade1 and ade2 cultures turn red. The intensity parent into the + cytoplasm brought in by the other parent. See Protocol: Curing cytoplasm of +, C. Styles 1981 (Blue Protocols Notebook). Sporulation Quality and efficiency is sensitive to many factors

Aris, John P.

312

The interaction map of yeast: terra incognita?  

PubMed Central

A systematic curation of the literature on Saccharomyces cerevisiae has yielded a comprehensive collection of experimentally observed interactions. This new resource augments current views of the topological structure of yeast's physical and genetic networks, but also reveals that existing studies cover only a fraction of the cell. PMID:16762048

Mellor, Joe; DeLisi, Charles

2006-01-01

313

Genomic Mismatch Scanning in Yeast December 2005  

E-print Network

that remains is "typical" salt/DNA precipitate. 13. Dissolve each pellet in 45 µL 1xTE. Pool each set and Matt Brauer of the Botstein lab for use with USB enzymes. A. Preparation of genomic DNA from yeast (Qiagen protocol) 3-4 days from colony Large amounts of high-quality genomic DNA are critical

Dunham, Maitreya

314

Global analysis of protein phosphorylation in yeast  

Microsoft Academic Search

Protein phosphorylation is estimated to affect 30% of the proteome and is a major regulatory mechanism that controls many basic cellular processes. Until recently, our biochemical understanding of protein phosphorylation on a global scale has been extremely limited; only one half of the yeast kinases have known in vivo substrates and the phosphorylating kinase is known for less than 160

Jason Ptacek; Geeta Devgan; Gregory Michaud; Heng Zhu; Xiaowei Zhu; Joseph Fasolo; Hong Guo; Ghil Jona; Ashton Breitkreutz; Richelle Sopko; Rhonda R. McCartney; Martin C. Schmidt; Najma Rachidi; Soo-Jung Lee; Angie S. Mah; Lihao Meng; Michael J. R. Stark; David F. Stern; Claudio de Virgilio; Mike Tyers; Brenda Andrews; Mark Gerstein; Barry Schweitzer; Paul F. Predki; Michael Snyder

2005-01-01

315

Glucose-Induced Acidification in Yeast Cultures  

ERIC Educational Resources Information Center

We present an investigation (for A-level biology students and equivalent) into the mechanism of glucose-induced extracellular acidification in unbuffered yeast suspensions. The investigation is designed to enhance understanding of aspects of the A-level curriculum that relate to the phenomenon (notably glucose catabolism) and to develop key skills…

Myers, Alan; Bourn, Julia; Pool, Brynne

2005-01-01

316

Arachidonic acid metabolites in pathogenic yeasts  

PubMed Central

Although most of what is known about the biology and function of arachidonic acid metabolites comes from the study of mammalian biology, these compounds can also be produced by lower eukaryotes, including yeasts and other fungi. It is also in this group of organisms that the least is known about the metabolic pathways leading to the production of these compounds as well as the functions of these compounds in the biology of fungi and yeasts. This review will deal with the discovery of oxylipins from polyunsaturated fatty acids, and more specifically the arachidonic acid derived eicosanoids, such as 3-hydroxy eicosatetraenoic acid, prostaglandin F2? and prostaglandin E2, in yeasts starting in the early 1990s. This review will also focus on what is known about the metabolic pathways and/or proteins involved in the production of these compounds in pathogenic yeasts. The possible roles of these compounds in the biology, including the pathology, of these organisms will be discussed. PMID:22873782

2012-01-01

317

Altered transcription in yeast expressing expanded polyglutamine  

E-print Network

, and the spinocerebellar atax- ias (SCAs), are caused by expansion in the number of glutamine- encoding CAG triplet repeats are responsible for at least eight fatal neurodegenerative diseases. In mouse models, proteins with expanded diseases and provide the potential for yeast-based screens for agents that reverse polyglu- tamine toxicity

Dunham, Maitreya

318

Antarctic Yeasts: Biodiversity and Potential Applications  

NASA Astrophysics Data System (ADS)

This review is an attempt in cataloguing the diversity of yeasts in Antarctica, highlight their biotechnological potential and understand the basis of adaptation to low temperature. As of now several psychrophilic and psychrotolerant yeasts from Antarctic soils and marine waters have been characterized with respect to their growth characteristics, ecological distribution and taxonomic significance. Interestingly most of these species belonged to basidiomycetous yeasts which as a group are known for their ability to circumvent and survive under stress conditions. Simultaneously their possible role as work horses in the biotechnological industry was recognized due to their ability to produce novel enzymes and biomolecules such as agents for the breakdown of xenobiotics, and novel pharmaceutical chemi cals. The high activity of psychrophilic enzymes at low and moderate temperatures offers potential economic benefits. As of now lipases from Pseudozyma antarctica have been extensively studied to understand their unique thermal stability at 90°C and also because of its use in the pharmaceutical, agriculture, food, cosmetics and chemical industry. A few of the other enzymes which have been studied include extracellular alpha-amylase and glucoamylase from the yeast Pseudozyma antarctica (Candida antarctica), an extra-cellular protease from Cryptococcus humicola, an aspartyl proteinase from Cryptococcus humicola, a novel extracellular subtilase from Leucosporidium antarcticum, and a xylanase from Cryptococcus adeliensis

Shivaji, S.; Prasad, G. S.

319

Molecular identification of yeasts associated with traditional Egyptian dairy products.  

PubMed

This study aimed to examine the diversity and ecology of yeasts associated with traditional Egyptian dairy products employing molecular techniques in yeast identification. A total of 120 samples of fresh and stored Domiati cheese, kariesh cheese, and "Matared" cream were collected from local markets and examined. Forty yeast isolates were cultured from these samples and identified using the restriction-fragment length polymorphism (RFLPs) of 5.8S-ITS rDNA region and sequencing of the domains D1 and D2 of the 26S rRNA gene. Yeasts were identified as Issatchenkia orientalis (13 isolates), Candida albicans (4 isolates), Clavispora lusitaniae (Candida lusitaniae) (9 isolates), Kodamaea ohmeri (Pichia ohmeri) (1 isolate), Kluyveromyces marxianus (6 isolates), and Candida catenulata (7 isolates). With the exception of C. lusitaniae, the D1/D2 26S rRNA gene sequences were 100% identical for the yeast isolates within the same species. Phylogenetic reconstruction of C. lusitaniae isolates grouped them into 3 distinguished clusters. Kariesh cheese was found to be the most diverse in its yeast floras and contained the highest total yeast count compared with other examined dairy products. This was linked to the acidic pH and lower salt content of this cheese, which favor the growth and survival of yeasts in foodstuffs. Stored Domiati cheese also contained diverse yeast species involving isolates of the pathogenic yeast C. albicans. This raises the possibility of dairy products being vehicles of transmission of pathogenic yeasts. PMID:19895478

El-Sharoud, W M; Belloch, C; Peris, D; Querol, A

2009-09-01

320

Analysis of genetic variation in clones of rubber (Hevea brasiliensis) from Asian, South and Central American origin using RAPDs markers AnÆlisis de la variaciÛn genØtica en clones de caucho (Hevea brasiliensis) de Asia, SuramØrica y CentroamØrica usando marcadores RAPD  

Microsoft Academic Search

Rubber (Hevea brasiliensis) represents a potential species for reforestation and commercial exploitation programmes in tropical countries such as Colombia. The genetic variability of a rubber collection kept at the Paraguaicito Experimental Station in Buenavista in the Quindio department of Colombia was studied to improve knowledge regarding this species and make better use of the trees available. A total of 25

Afanador Kafuri; Rafael Arango Isaza; Mario Lobo Arias

321

Strong static magnetic field effects on yeast proliferation and distribution.  

PubMed

The present study focuses on the effects of gradient magnetic fields on the behavior of yeast, such as its proliferation and mass distribution, and evaluates the effects of magnetism on materials in the yeast culture system. Yeast, Saccharomyces cerevisiae, was incubated in a liquid medium under magnetic fields (flux density B = 14 T). When yeast in a tube was exposed to 9-14 T magnetic fields with a maximum flux density gradient of dB/dx = 94 T/m, where x is the space coordinate, the rate of yeast proliferation under the magnetic fields decreased after 16 h of incubation compared to that of the control group. The physical properties of the yeast culture system were investigated to discover the mechanism responsible for the observed deceleration in yeast proliferation under magnetic fields. Gas pressure inside the yeast culture flask was compared with and without exposure to a magnetic field. The results suggested that the gas pressure inside a flask with 6 T, 60 T/m slowly increased in comparison to the pressure inside a control tube. Due to the diamagnetism of water (medium solution) and yeast, the liquid surface distinctly inclined under gradient magnetic fields, and the hydrostatic force in suspension was strengthened by the diamagnetic forces. In addition, magnetophoresis of the yeast cells in the medium solution exhibited localization of the yeast sedimentation pattern. The roles of magnetically changed gas-transport processes, hydrostatic pressures acting on the yeast, and changes in the distribution of the yeast sedimentation, as well as the possible effects of magnetic fields on yeast respiratory systems in the observed disturbance of the proliferation are discussed. PMID:15522694

Iwasaka, Masakazu; Ikehata, Masateru; Miyakoshi, Junji; Ueno, Shoogo

2004-12-01

322

Micro-organisms in latex and natural rubber coagula of Hevea brasiliensis and their impact on rubber composition, structure and properties.  

PubMed

Natural rubber, produced by coagulation of the latex from the tree Hevea brasiliensis, is an important biopolymer used in many applications for its outstanding properties. Besides polyisoprene, latex is rich in many nonisoprene components such as carbohydrates, proteins and lipids and thereby constitutes a favourable medium for the development of micro-organisms. The fresh rubber coagula obtained by latex coagulation are not immediately processed, allowing the development of various microbial communities. The time period between tree tapping and coagula processing is called maturation, during which an evolution of the properties of the corresponding dry natural rubber occurs. This evolution is partly related to the activity of micro-organisms and to the modification of the biochemical composition. This review synthesizes the current knowledge on microbial populations in latex and natural rubber coagula of H. brasiliensis and the changes they induce on the biochemistry and technical properties of natural rubber during maturation. PMID:24891014

Salomez, M; Subileau, M; Intapun, J; Bonfils, F; Sainte-Beuve, J; Vaysse, L; Dubreucq, E

2014-10-01

323

The chemoenzymatic synthesis of( S)-13-hydroxyoctadeca-(9 Z, 11E)-dienoic acid using the hydroxynitrile lyase from Hevea brasiliensis  

Microsoft Academic Search

(S)-13-hydroxyoctadeca-(9Z, 11E)-dienoic acid (1) was synthesized in nine steps starting from (E)-2-octenal (2). The (S)-hydroxynitrile lyase cloned from Hevea brasiliensis, that has been overexpressed in Pichia pastoris, was used to interconvert 2 into (S)-cyanohydrin 3. The subsequent butyrate 6 was rearranged using the palladium-bis-(acetonitrile)-dichloride to give the unsaturated nitrile 7 which was fully elaborated to the hydroxy acid 1 in

Dean V. Johnson; Herfried Griengl

1997-01-01

324

Novel access to chiral 1,1?-disubstituted ferrocene derivatives via double stereoselective cyanohydrin synthesis exploiting the hydroxynitrile lyase from Hevea brasiliensis  

Microsoft Academic Search

A novel route to chiral ferrocene derivatives involving the application of hydroxynitrile lyase from Hevea brasiliensis has been developed. The method allows the conversion of formylferrocene 1 and 1,1?-diformylferrocene 2 into their corresponding chiral cyanohydrins. (R)-(Cyanohydroxymethyl)ferrocene 3 and (R,R)-1,1?-bis(cyanohydroxymethyl)ferrocene 4 were obtained in high yield and stereochemical purity using this method. The full structural characterisation of the latter including the

Richard F. G. Fröhlich; Antonina A. Zabelinskaja-Mackova; Martin H. Fechter; Herfried Griengl

2003-01-01

325

Genetics of anthracnose panel canker disease resistance and its relationship with yield and growth characters in half-sib progenies of rubber tree (Hevea brasiliensis)  

Microsoft Academic Search

Rubber tree (Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell-Arg) anthracnose panel canker disease resistance, caused by Colletotrichum gloeosporioides (Penz.) Sacc., and growth and yield characters were assessed at three years old in the nursery, in 18 half-sib progenies. There were highly significant (P < 0.01) genetic differences among progenies for most characters. The genetic component of variance accounted for

Paulo de Souza Gonçalves; Edson Luiz Furtado; Ondino Cleante Bataglia; Altino Aldo Ortolani; André May; Giselle Olmos Belletti

1999-01-01

326

Acaulospora brasiliensis comb. nov. and Acaulospora alpina ( Glomeromycota ) from upland Scotland: morphology, molecular phylogeny and DNA-based detection in roots  

Microsoft Academic Search

Spores of two supposedly arbuscular mycorrhizal fungal species, new to the United Kingdom and recently described as Acaulospora alpina and Ambispora brasiliensis (Glomeromycota), were discovered in soil samples from moorland in upland Scotland. Soil and plant trap pot cultures were established, but\\u000a attempts to establish these fungi in single-species pot cultures with Plantago lanceolata as host were unsuccessful. Nevertheless, based

Manuela Krüger; Christopher Walker; Arthur Schüßler

2011-01-01

327

Cutaneous manifestations of Nocardia brasiliensis infection in Taiwan during 2002-2012-clinical studies and molecular typing of pathogen by gyrB and 16S gene sequencing.  

PubMed

To observe the clinicopathologic and resistance profiles of the Nocardia brasiliensis causing cutaneous nocardiosis in Taiwan, 12 N. brasiliensis isolates were prospectively collected from patients with cutaneous nocardiosis in a hospital during 2002-2012. Clinicopathologic data were obtained, and isolates were identified by biochemical methods and 16S rRNA sequencing. Susceptibilities to 14 antimicrobial compounds were tested. Isolates were further genotyped by sequencing of 16S rRNA, secA1, hsp65, and gyrB genes. The nodulopustular pyoderma associated with sporotrichoid spreading was the most common skin presentations caused by N. brasiliensis. All of the isolates were susceptible to amikacin, gentamicin, tobramycin, piperacillin/tazobactam, and trimethoprim/sulfamethoxazole and resistant to kanamycin, erythromycin, and oxacillin, while susceptibilities to imipenem, vancomycin, penicillin-G, tetracycline, clindamycin, and ciprofloxacin varied among the 12 isolates. GyrB genotyping delineated the 12 isolates into 2 major groups, which was coincident with different single nucleotide substitutions at position 160 (G versus T) of 16S rRNA, different levels of imipenem minimum inhibition concentration (4-32 versus 0.25-0.75 mg/L), and prevalence of lymphadenitis (66.7 versus 16.7%). We have noted that tiny pustular lesions can be the first sign of cutaneous nocardiosis, which we believe has not been previously emphasized. No resistance to trimethoprim and sulfamethoxazole was found; therefore, sulphonamide drugs remain effective for treatment of cutaneous nocardiosis in Taiwan. PMID:23791388

Chen, Kuo-Wei; Lu, Chun-Wei; Huang, Ting-Chi; Lu, Chin-Fang; Liau, Yea-Ling; Lin, Jeng-Fong; Li, Shu-Ying

2013-09-01

328

Uncommon opportunistic yeast bloodstream infections from Qatar.  

PubMed

Eleven uncommon yeast species that are associated with high mortality rates irrespective of antifungal therapy were isolated from 17/187 (201 episodes) pediatric and elderly patients with fungemia from Qatar. The samples were taken over a 6-year period (January 2004-December 2010). Isolated species included Kluyveromyces marxianus, Lodderomyces elongisporus, Lindnera fabianii, Candida dubliniensis, Meyerozyma guilliermondii, Candida intermedia, Pichia kudriavzevii, Yarrowia lipolytica, Clavispora lusitaniae, Candida pararugosa, and Wickerhamomyces anomalus. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry provided correct identifications compared with molecular analysis testing of the same isolates. Low minimal inhibitory concentrations were found when isavuconazole and voriconazole were used for all uncommon yeast species evaluated in this study. Resistance to antifungal drugs was low and remained restricted to a few species. PMID:24934803

Taj-Aldeen, Saad J; AbdulWahab, Atqah; Kolecka, Anna; Deshmukh, Anand; Meis, Jacques F; Boekhout, Teun

2014-07-01

329

Prion formation by a yeast GLFG nucleoporin  

PubMed Central

The self-assembly of proteins into higher order structures is both central to normal biology and a dominant force in disease. Certain glutamine/asparagine (Q/N)-rich proteins in the budding yeast Saccharomyces cerevisiae assemble into self-replicating amyloid-like protein polymers, or prions, that act as genetic elements in an entirely protein-based system of inheritance. The nuclear pore complex (NPC) contains multiple Q/N-rich proteins whose self-assembly has also been proposed to underlie structural and functional properties of the NPC. Here we show that an essential sequence feature of these proteins—repeating GLFG motifs—strongly promotes their self-assembly into amyloids with characteristics of prions. Furthermore, we demonstrate that Nup100 can form bona fide prions, thus establishing a previously undiscovered ability of yeast GLFG nucleoporins to adopt this conformational state in vivo. PMID:22561191

Halfmann, Randal; Wright, Jessica R.; Alberti, Simon; Lindquist, Susan; Rexach, Michael

2012-01-01

330

Genetic activity of vinylidene chloride in yeast.  

PubMed

Vinylidene chloride (VDC) was tested for its ability to induce both point mutation and mitotic gene conversion in a diploid strain (D7) of the yeast Saccharomyces cerevisiae in a suspension test with and without a mammalian microsomal activation system, and in the intrasanguineous host-mediated assay in mice. In suspension tests with D7, VCD was toxic but not genetically active without microsomal activation. When a mouse liver 10 000 X g supernatant was included in the suspension tests, dose-related increases in both point mutation and mitotic gene conversion were seen at survival levels greater than 50%, at doses of VCD above 20 mM. In the host-mediated assay, VDC induced both point mutation and mitotic gene conversion when recovered from the liver and kidneys after both acute and sub-acute dosing. Yeasts recovered from the lungs showed little, if any, increase in either point mutation or mitotic gene conversion. PMID:7027030

Bronzetti, G; Bauer, C; Corsi, C; Leporini, C; Nieri, R; del Carratore, R

1981-06-01

331

Mapping the functional yeast ABC transporter interactome  

PubMed Central

ABC transporters are a ubiquitous class of integral membrane proteins of immense clinical interest because of their strong association with human disease and pharmacology. To improve our understanding of these proteins, we used Membrane Yeast Two-Hybrid (MYTH) technology to map the protein interactome of all non-mitochondrial ABC transporters in the model organism Saccharomy cescerevisiae, and combined this data with previously reported yeast ABC transporter interactions in the BioGRID database to generate a comprehensive, integrated interactome. We show that ABC transporters physically associate with proteins involved in a surprisingly diverse range of functions. We specifically examine the importance of the physical interactions of ABC transporters in both the regulation of one another and in the modulation of proteins involved in zinc homeostasis. The interaction network presented here will be a powerful resource for increasing our fundamental understanding of the cellular role and regulation of ABC transporters. PMID:23831759

Snider, Jamie; Hanif, Asad; Lee, Mid Eum; Jin, Ke; Yu, Analyn R.; Graham, Chris; Chuk, Matthew; Damjanovic, Dunja; Wierzbicka, Marta; Tang, Priscilla; Balderes, Dina; Wong, Victoria; Jessulat, Matthew; Darowski, Katelyn D.; Luis, Bryan-Joseph San; Shevelev, Igor; Sturley, Stephen L; Boone, Charles; Greenblatt, Jack F.; Zhang, Zhaolei; Paumi, Christian M.; Babu, Mohan; Park, Hay-Oak; Michaelis, Susan; Stagljar, Igor

2013-01-01

332

Isolation of Yeast DNA Prepare in advance  

E-print Network

. · Powdered dry ice (2-4 lbs). 1. Collect 5-10 OD units of yeast cells (e.g., 5 ml saturated SD culture at OD. Vortexing too long will shear genomic DNA into small pieces. 5. Place tubes in powdered dry ice. Allow and place on ice. · TENTS buffer: 100 mM NaCl, 10 mM Tris-HCl, pH 8, 1 mM EDTA, 2% Triton X-100, 1% SDS

Aris, John P.

333

Functional artificial free-standing yeast biofilms  

Microsoft Academic Search

Here we report fabrication of artificial free-standing yeast biofilms built using sacrificial calcium carbonate-coated templates and layer-by-layer assembly of extracellular matrix-mimicking polyelectrolyte multilayers. The free-standing biofilms are freely floating multilayered films of oppositely charged polyelectrolytes and live cells incorporated in the polyelectrolyte layers. Such biofilms were initially formed on glass substrates of circular and ribbon-like shapes coated with thin layers

Svetlana A. Konnova; Mehmet Kahraman; Alsu I. Zamaleeva; Mustafa Culha; Vesselin N. Paunov; Rawil F. Fakhrullin

2011-01-01

334

The mitochondrial pathway in yeast apoptosis  

Microsoft Academic Search

Mitochondria are not only important for the energetic status of the cell, but are also the fatal organelles deciding about\\u000a cellular life and death. Complex mitochondrial features decisive for cell death execution in mammals are present and functional\\u000a in yeast: AIF and cytochrome c release to the cytosol, mitochondrial fragmentation as well as mitochondrial hyperpolarisation followed by an oxidative burst,

Tobias Eisenberg; Sabrina Büttner; Guido Kroemer; Frank Madeo

2007-01-01

335

X-ray irradiation of yeast cells  

Microsoft Academic Search

Saccharomyces Cerevisiae yeast cells were irradiated using the soft X-ray laser-plasma source at Rutherford Laboratory. The aim was to produce a selective damage of enzyme metabolic activity at the wall and membrane level (responsible for fermentation) without interfering with respiration (taking place in mitochondria) and with nuclear and DNA activity. The source was calibrated by PIN diodes and X-ray spectrometers.

Alessandra Masini; Dimitri Batani; Fabio Previdi; Aldo Conti; Francesca Pisani; Cesare Botto; Fulvia Bortolotto; Flavia Torsiello; I. C. Edmund Turcu; Ric M. Allott; Nicola Lisi; Marziale Milani; Michele Costato; Achille Pozzi; Michel Koenig

1997-01-01

336

Fermentation of Cellodextrins by Different Yeast Strains  

PubMed Central

The fermentation of cellodextrins by eight yeast species capable of fermenting cellobiose was monitored. Only two of these species, Torulopsis molischiana and T. wickerhamii, were able to ferment ?-glucosides with a degree of polymerization between one and six. These two species showed exocellular ?-glucosidase activity. Four other species were able to ferment cellotriose, and the last two species only fermented cellobiose. These latter six species produced a ?-glucosidase capable of attacking cellodextrins, but this enzyme was endocellular. PMID:16346606

Gonde, Pierre; Blondin, Bruno; Leclerc, Marc; Ratomahenina, Robert; Arnaud, Alain; Galzy, Pierre

1984-01-01

337

Debaryomyces hansenii : An Osmotolerant and Halotolerant Yeast  

Microsoft Academic Search

The yeast Debaryomyces hansenii which was isolated from saline environments such as sea water, concentrated brines, salty food, is one of the most halotolerant\\u000a species. It can grow in media containing as high as 4 M NaCl, while the growth of Saccharomyces cerevisiae is limited in media with more than 1.7 M NaCl. This species is very important for food

Monika Aggarwal; Alok K. Mondal

2009-01-01

338

A Sampling of the Yeast Proteome  

Microsoft Academic Search

In this study, we examined yeast proteins by two-dimensional (2D) gel electrophoresis and gathered quan- titative information from about 1,400 spots. We found that there is an enormous range of protein abundance and, for identified spots, a good correlation between protein abundance, mRNA abundance, and codon bias. For each molecule of well-translated mRNA, there were about 4,000 molecules of protein.

B. FUTCHER; G. I. LATTER; P. MONARDO; C. S. MCLAUGHLIN; J. I. GARRELS

1999-01-01

339

Genetic toxicity of erythrosine in yeast.  

PubMed

The genetic activity of erythrosine, a fluorescein dye used as a color additive, was studied in assays with growing cells of different strains of Saccharomyces cerevisiae. Erythrosine induced mitotic gene conversion and reverse mutation in strains D7 and XV185-14C of yeast. It failed, however, to increase mitotic recombination in strain D5. These results show that erythrosine possesses genotoxic activity for eukaryotic cells. PMID:6096707

Matula, T I; Downie, R H

1984-01-01

340

Complete DNA sequence of yeast chromosome XI  

Microsoft Academic Search

The complete DNA sequence of the yeast Saccharomyces cerevisiae chromosome XI has been determined. In addition to a compact arrangement of potential protein coding sequences, the 666,448-base-pair sequence has revealed general chromosome patterns; in particular, alternating regional variations in average base composition correlate with variations in local gene density along the chromosome. Significant discrepancies with the previously published genetic map

B. Dujon; D. Alexandraki; B. André; W. Ansorge; V. Baladron; J. P. G. Ballesta; A. Banrevi; P. A. Bolle; M. Bolotin-Fukuhara; P. Bossier; G. Bou; J. Boyer; M. J. Buitrago; G. Cherét; L. Colleaux; B. Dalgnan-Fornier; F. Del Rey; C. Dion; H. Domdey; A. Düsterhöft; S. Düsterhus; K.-D. Entian; H. Erfle; P. F. Esteban; H. Feldmann; L. Fernandes; G. M. Fobo; C. Fritz; H. Fukuhara; C. Gabel; L. Gaillon; J. M. Carcia-Cantalejo; J. J. Garcia-Ramirez; M. E. Gent; M. Ghazvini; A. Goffeau; A. Gonzaléz; D. Grothues; P. Guerreiro; J. Hegemann; N. Hewitt; F. Hilger; C. P. Hollenberg; O. Horaitis; K. J. Indge; A. Jacquier; C. M. James; J. C. Jauniaux; A. Jimenez; H. Keuchel; L. Kirchrath; K. Kleine; P. Kötter; P. Legrain; S. Liebl; E. J. Louis; A. Maia E Silva; C. Marck; A.-L. Monnier; D. Möstl; S. Müller; B. Obermaier; S. G. Oliver; C. Pallier; S. Pascolo; F. Pfeiffer; P. Philippsen; R. J. Planta; F. M. Pohl; T. M. Pohl; R. Pöhlmann; D. Portetelle; B. Purnelle; V. Puzos; M. Ramezani Rad; S. W. Rasmussen; M. Remacha; J. L. Revuelta; G.-F. Richard; M. Rieger; C. Rodrigues-Pousada; M. Rose; T. Rupp; M. A. Santos; C. Schwager; C. Sensen; J. Skala; H. Soares; F. Sor; J. Stegemann; H. Tettelin; A. Thierry; M. Tzermia; L. A. Urrestarazu; L. van Dyck; J. C. van Vliet-Reedijk; M. Valens; M. Vandenbo; C. Vilela; S. Vissers; D. von Wettstein; H. Voss; S. Wiemann; G. Xu; J. Zimmermann; M. Haasemann; I. Becker; H. W. Mewes

1994-01-01

341

The flavoproteome of the yeast Saccharomyces cerevisiae?  

PubMed Central

Genome analysis of the yeast Saccharomyces cerevisiae identified 68 genes encoding flavin-dependent proteins (1.1% of protein encoding genes) to which 47 distinct biochemical functions were assigned. The majority of flavoproteins operate in mitochondria where they participate in redox processes revolving around the transfer of electrons to the electron transport chain. In addition, we found that flavoenzymes play a central role in various aspects of iron metabolism, such as iron uptake, the biogenesis of iron–sulfur clusters and insertion of the heme cofactor into apocytochromes. Another important group of flavoenzymes is directly (Dus1-4p and Mto1p) or indirectly (Tyw1p) involved in reactions leading to tRNA-modifications. Despite the wealth of genetic information available for S. cerevisiae, we were surprised that many flavoproteins are poorly characterized biochemically. For example, the role of the yeast flavodoxins Pst2p, Rfs1p and Ycp4p with regard to their electron donor and acceptor is presently unknown. Similarly, the function of the heterodimeric Aim45p/Cir1p, which is homologous to the electron-transferring flavoproteins of higher eukaryotes, in electron transfer processes occurring in the mitochondrial matrix remains to be elucidated. This lack of information extends to the five membrane proteins involved in riboflavin or FAD transport as well as FMN and FAD homeostasis within the yeast cell. Nevertheless, several yeast flavoproteins, were identified as convenient model systems both in terms of their mechanism of action as well as structurally to improve our understanding of diseases caused by dysfunctional human flavoprotein orthologs. PMID:24373875

Gudipati, Venugopal; Koch, Karin; Lienhart, Wolf-Dieter; Macheroux, Peter

2014-01-01

342

Mechanisms of autophagy and pexophagy in yeasts.  

PubMed

Autophagy is a process of recycling of the intracellular constituents using vacuoles (lysosomes). General autophagy occurs due to involvement of highly conservative components found in all eukaryotes, from yeasts to higher plants and humans. Autophagy also could be a selective process and be involved in regulation of the cellular number of organelles, including that of peroxisomes. The process of specific autophagic peroxisome degradation is known as pexophagy. Yeasts appear to be convenient model for studying molecular mechanisms of pexophagy, and most known ATG genes (from the term AuTophaGy) were identified in yeast studies. This review examines characteristics of general autophagy, other types of autophagy as well as pexophagy, in particular, functions of Atg proteins in general autophagy and in macro- and micropexophagy. Special attention is given to mechanisms of phagophore assembly, the role of phosphatidylinositol-3-phosphate in pexophagy, the role of peroxines (proteins involved in peroxisome biogenesis) in pexophagy, as well as properties of Atg proteins specifically involved in micropexophagy. PMID:22150273

Sibirny, A A

2011-12-01

343

Ribosome Biogenesis in the Yeast Saccharomyces cerevisiae  

PubMed Central

Ribosomes are highly conserved ribonucleoprotein nanomachines that translate information in the genome to create the proteome in all cells. In yeast these complex particles contain four RNAs (>5400 nucleotides) and 79 different proteins. During the past 25 years, studies in yeast have led the way to understanding how these molecules are assembled into ribosomes in vivo. Assembly begins with transcription of ribosomal RNA in the nucleolus, where the RNA then undergoes complex pathways of folding, coupled with nucleotide modification, removal of spacer sequences, and binding to ribosomal proteins. More than 200 assembly factors and 76 small nucleolar RNAs transiently associate with assembling ribosomes, to enable their accurate and efficient construction. Following export of preribosomes from the nucleus to the cytoplasm, they undergo final stages of maturation before entering the pool of functioning ribosomes. Elaborate mechanisms exist to monitor the formation of correct structural and functional neighborhoods within ribosomes and to destroy preribosomes that fail to assemble properly. Studies of yeast ribosome biogenesis provide useful models for ribosomopathies, diseases in humans that result from failure to properly assemble ribosomes. PMID:24190922

Woolford, John L.; Baserga, Susan J.

2013-01-01

344

Engineered yeast for enhanced CO2 mineralization†  

PubMed Central

In this work, a biologically catalyzed CO2 mineralization process for the capture of CO2 from point sources was designed, constructed at a laboratory scale, and, using standard chemical process scale-up protocols, was modeled and evaluated at an industrial scale. A yeast display system in Saccharomyces cerevisae was used to screen several carbonic anhydrase isoforms and mineralization peptides for their impact on CO2 hydration, CaCO3 mineralization, and particle settling rate. Enhanced rates for each of these steps in the CaCO3 mineralization process were confirmed using quantitative techniques in lab-scale measurements. The effect of these enhanced rates on the CO2 capture cost in an industrial scale CO2 mineralization process using coal fly ash as the CaO source was evaluated. The model predicts a process using bCA2- yeast and fly ash is ~10% more cost effective per ton of CO2 captured than a process with no biological molecules, a savings not realized by wild-type yeast and high-temperature stable recombinant CA2 alone or in combination. The levelized cost of electricity for a power plant using this process was calculated and scenarios in which this process compares favorably to CO2 capture by MEA absorption process are presented.

Barbero, Roberto; Carnelli, Lino; Simon, Anna; Kao, Albert; Monforte, Alessandra d'Arminio; Ricco, Moreno; Bianchi, Daniele; Belcher, Angela

2014-01-01

345

Wood impregnation of yeast lees for winemaking.  

PubMed

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

2015-03-15

346

Effects of yeast immobilization on bioethanol production.  

PubMed

The current study evaluated a newer method, which includes a dehydration step, of immobilizing Saccharomyces cerevisiae L-77 and S. cerevisiae L-73 onto hydroxylapatite and chamotte ceramic supports. The efficiency of cell immobilization on chamotte was significantly higher than hydroxylapatite. Immobilized yeast preparations were investigated for their ethanol-producing capabilities. The glucose concentration in a fermentation medium was 100 mg/mL. Immobilized preparations produced the same amount of ethanol (48 ± 0.5 mg/mL) as free cells after 36 H of fermentation. During the early stages of fermentation, immobilized yeast cells produced ethanol at a higher rate than free cells. Yeast preparations immobilized on both supports (hydroxylapatite and chamotte) were successfully used in six sequential batch fermentations without any loss of activity. The chamotte support was more stable in the fermentation medium during these six cycles of ethanol production. In addition to the high level of ethanol produced by cells immobilized on chamotte, the stability of this support and its low cost make it a promising material for biotechnologies associated with ethanol production. PMID:24180336

Borovikova, Diana; Scherbaka, Rita; Patmalnieks, Aloizijs; Rapoport, Alexander

2014-01-01

347

Yeast Exocytic v-SNAREs Confer Endocytosis  

PubMed Central

In yeast, homologues of the synaptobrevin/VAMP family of v-SNAREs (Snc1 and Snc2) confer the docking and fusion of secretory vesicles at the cell surface. As no v-SNARE has been shown to confer endocytosis, we examined whether yeast lacking the SNC genes, or possessing a temperature-sensitive allele of SNC1 (SNC1ala43), are deficient in the endocytic uptake of components from the cell surface. We found that both SNC and temperature-shifted SNC1ala43 yeast are deficient in their ability to deliver the soluble dye FM4–64 to the vacuole. Under conditions in which vesicles accumulate, FM4–64 stained primarily the cytoplasm as well as fragmented vacuoles. In addition, ?-factor–stimulated endocytosis of the ?-factor receptor, Ste2, was fully blocked, as evidenced using a Ste2-green fluorescent protein fusion protein as well as metabolic labeling studies. This suggests a direct role for Snc v-SNAREs in the retrieval of membrane proteins from the cell surface. Moreover, this idea is supported by genetic and physical data that demonstrate functional interactions with t-SNAREs that confer endosomal transport (e.g., Tlg1,2). Notably, Snc1ala43 was found to be nonfunctional in cells lacking Tlg1 or Tlg2. Thus, we propose that synaptobrevin/VAMP family members are engaged in anterograde and retrograde protein sorting steps between the Golgi and the plasma membrane. PMID:11029060

Gurunathan, Sangiliyandi; Chapman-Shimshoni, Daphne; Trajkovic, Selena; Gerst, Jeffrey E.

2000-01-01

348

Evolution of the genetic code in yeasts.  

PubMed

During the last 30 years, a number of genetic code alterations have been uncovered in bacteria and in the mitochondria and cytoplasm of various eukaryotes, invalidating the hypothesis that the genetic code is universal and frozen. In the mitochondria of most yeasts, the UGA stop codon is decoded as tryptophan and the four leucine codons of the CUN family (N = any nucleotide) are decoded as threonine. Recently, a unique genetic code change involving the decoding of the leucine CUG codon as serine was discovered in the cytoplasm of Candida and Debaryomyces species, indicating that the genetic code of yeasts may be under specific evolutionary pressures whose molecular nature is not yet fully understood. This genetic code alteration is mediated by a novel serine-tRNA that acquired a leucine 5'-CAG-3' anticodon (ser-tRNACAG) through insertion of an adenosine in the intron of its gene. This event, which occurred 272 +/- 25 million years ago, reprogrammed the identity of approximately 30 000 CUG codons existent in the ancestor of these yeasts and had a profound impact on the evolution of the genus Candida and of other species. Here, we review the most recent results and concepts arising from the study of this genetic code change and highlight how its study is changing our views of the evolution of the genetic code. PMID:16498697

Miranda, Isabel; Silva, Raquel; Santos, Manuel A S

2006-02-01

349

Effect of anti-glycosphingolipid monoclonal antibodies in pathogenic fungal growth and differentiation. Characterization of monoclonal antibody MEST-3 directed to Manp?1->3Manp?1->2IPC  

PubMed Central

Background Studies carried out during the 1990's demonstrated the presence of fungal glycoinositol phosphorylceramides (GIPCs) with unique structures, some of them showed reactivity with sera of patients with histoplasmosis, paracoccidioidomycosis or aspergillosis. It was also observed that fungal GIPCs were able to inhibit T lymphocyte proliferation "in vitro", and studies regarding the importance of these molecules to fungal survival showed that many species of fungi are vulnerable to inhibitors of sphingolipid biosynthesis. Results In this paper, we describe a detailed characterization of an IgG2a monoclonal antibody (mAb), termed MEST-3, directed to the Paracoccidioides brasiliensis glycolipid antigen Pb-2 (Manp?1?3Manp?1?2IPC). mAb MEST-3 also recognizes GIPCs bearing the same structure in other fungi. Studies performed on fungal cultures clearly showed the strong inhibitory activity of MEST-3 on differentiation and colony formation of Paracoccidioides brasiliensis, Histoplasma capsulatum and Sporothrix schenckii. Similar inhibitory results were observed when these fungi where incubated with a different mAb, which recognizes GIPCs bearing terminal residues of ?-D-galactofuranose linked to mannose (mAb MEST-1). On the other hand, mAb MEST-2 specifically directed to fungal glucosylceramide (GlcCer) was able to promote only a weak inhibition on fungal differentiation and colony formation. Conclusions These results strongly suggest that mAbs directed to specific glycosphingolipids are able to interfere on fungal growth and differentiation. Thus, studies on surface distribution of GIPCs in yeast and mycelium forms of fungi may yield valuable information regarding the relevance of glycosphingolipids in processes of fungal growth, morphological transition and infectivity. PMID:20156351

2010-01-01

350

YeastMed: an XML-Based System for Biological Data Integration of Yeast  

E-print Network

A key goal of bioinformatics is to create database systems and software platforms capable of storing and analysing large sets of biological data. Hundreds of biological databases are now available and provide access to huge amount of biological data. SGD, Yeastract, CYGD-MIPS, BioGrid and PhosphoGrid are five of the most visited databases by the yeast community. These sources provide complementary data on biological entities. Biologists are brought systematically to query these data sources in order to analyse the results of their experiments. Because of the heterogeneity of these sources, querying them separately and then manually combining the returned result is a complex and laborious task. To provide transparent and simultaneous access to these sources, we have developed a mediator-based system called YeastMed. In this paper, we present YeastMed focusing on its architecture.

Briache, Abdelaali; Kerzazi, Amine; Navas-Delgado, Ismael; Montes, Jose F Aldana; Hassani, Badr D Rossi; Lairini, Khalid

2010-01-01

351

Frontiers of yeast metabolic engineering: diversifying beyond ethanol and Saccharomyces.  

PubMed

Microbial systems provide an attractive, renewable route to produce desired organic molecules such as fuels and chemicals. While attention within the field of metabolic engineering has mostly focused on Escherichia coli, yeast is a potent host and growing host for industrial products and has many outstanding, biotechnologically desirable native traits. Thus, there has been a recent shift in focus toward yeast as production hosts to replace E. coli. As such, products have diversified in yeast beyond simply ethanol. Additionally, nonconventional yeasts have been considered to move beyond Saccharomyces cerevisiae. This review highlights recent advances in metabolic engineering of yeasts for producing value-added chemical compounds including alcohols, sugar derivatives, organic acids, fats, terpenes, aromatics, and polyketides. Furthermore, we will also discuss the future direction of metabolic engineering of yeasts. PMID:23541504

Liu, Leqian; Redden, Heidi; Alper, Hal S

2013-12-01

352

Ecology and Biodiversity of Yeasts with Potential Value in Biotechnology  

NASA Astrophysics Data System (ADS)

In the latest edition of the standard treatise of yeasts, in 1998, 700 species were described. Since then, the number of recognized yeast species has doubled, with a steep increase particularly in the number of the basidiomycetous yeasts. Of all these yeast species, only about a dozen is used at industrial scale, and some 70 - 80 species have been shown at laboratory scale to possess potential value in biotechnology; their ratio is, in the best case, 5 - 10 %. If it is accepted, that according to a modest estimate, the known yeast species represent only 5 % of the total number which may inhabit the Earth, then there is ample room to search for new species with novel potential to exploit. Where could these yeasts be discovered?

Deak, T.

353

Isolation and characterization of ethanol tolerant yeast strains.  

PubMed

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

2013-01-01

354

Not your ordinary yeast: non-Saccharomyces yeasts in wine production uncovered.  

PubMed

Saccharomyces cerevisiae and grape juice are 'natural companions' and make a happy wine marriage. However, this relationship can be enriched by allowing 'wild' non-Saccharomyces yeast to participate in a sequential manner in the early phases of grape must fermentation. However, such a triangular relationship is complex and can only be taken to 'the next level' if there are no spoilage yeast present and if the 'wine yeast' - S. cerevisiae - is able to exert its dominance in time to successfully complete the alcoholic fermentation. Winemakers apply various 'matchmaking' strategies (e.g. cellar hygiene, pH, SO2 , temperature and nutrient management) to keep 'spoilers' (e.g. Dekkera bruxellensis) at bay, and allow 'compatible' wild yeast (e.g. Torulaspora delbrueckii, Pichia kluyveri, Lachancea thermotolerans and Candida/Metschnikowia pulcherrima) to harmonize with potent S. cerevisiae wine yeast and bring the best out in wine. Mismatching can lead to a 'two is company, three is a crowd' scenario. More than 40 of the 1500 known yeast species have been isolated from grape must. In this article, we review the specific flavour-active characteristics of those non-Saccharomyces species that might play a positive role in both spontaneous and inoculated wine ferments. We seek to present 'single-species' and 'multi-species' ferments in a new light and a new context, and we raise important questions about the direction of mixed-fermentation research to address market trends regarding so-called 'natural' wines. This review also highlights that, despite the fact that most frontier research and technological developments are often focussed primarily on S. cerevisiae, non-Saccharomyces research can benefit from the techniques and knowledge developed by research on the former. PMID:24164726

Jolly, Neil P; Varela, Cristian; Pretorius, Isak S

2014-03-01

355

Relative Incidence of Ascomycetous Yeasts in Arctic Coastal Environments  

Microsoft Academic Search

Previous studies of fungi in polar environments have revealed a prevalence of basidiomycetous yeasts in soil and in subglacial\\u000a environments of polythermal glaciers. Ascomycetous yeasts have rarely been reported from extremely cold natural environments,\\u000a even though they are known contaminants of frozen foods. Using media with low water activity, we have isolated various yeast\\u000a species from the subglacial ice of

Lorena Butinar; Tadeja Strmole; Nina Gunde-Cimerman

2011-01-01

356

Genetic transformation and biotechnological application of the yeast Arxula adeninivorans  

Microsoft Academic Search

The relatively unknown, non-pathogenic, dimorphic, haploid, ascomycetous yeast Arxula adeninivorans exhibits some unusual properties which are of biotechnological interest. The yeast is able to assimilate and ferment many\\u000a compounds as sole source of carbon and\\/or nitrogen, it utilises n-alkanes and degrades starch efficiently. A. adeninivorans features such as thermo- and haloresistance as well as the yeast's uncommon growth and secretion

T. Wartmann; G. Kunze

2000-01-01

357

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

1990-01-01

358

Prevalence of Candida dubliniensis Isolates in a Yeast Stock Collection  

Microsoft Academic Search

To establish the historical prevalence of the novel yeast species Candida dubliniensis, a survey of 2,589 yeasts originally identified as Candida albicans and maintained in a stock collection dating back to the early 1970s was undertaken. A total of 590 yeasts, including 93 (18.5%) b-glucosidase-negative isolates among 502 isolates that showed abnormal colony colors on a differential chromogenic agar and

FRANK C. ODDS; LUC VAN NUFFEL; GERY DAMS

1998-01-01

359

Detection and identification of wild yeast in Koumiss.  

PubMed

Koumiss is a slightly alcoholic fermented mare's milk beverage, originally obtained by using a natural mixed starter of lactic acid bacteria and yeasts. Yeast is an important component of Koumiss processing which can affect the aroma, texture, as well as the nutrients beneficial to human health, but few reports have examined the yeast ecology of local ecosystems. The purpose of this study was to isolate and identify the yeast present in Koumiss from three representative regions of China using a polyphasic method. A total of 655 yeast isolates were obtained from 96 Koumiss samples collected from three regions in China. Koumiss harbored yeast populations at 5-7 log CFU/ml. Twelve different yeast species belonging to nine genera were detected in the Koumiss samples tested, including Candida pararugosa, Dekkera anomala, Geotrichum sp., Issatchenkia orientalis, Kazachstania unispora, Kluyveromyces marxianus, Pichia deserticola, Pichia fermentans, Pichia manshurica, Pichia membranaefaciens, Saccharomyces cerevisiae and Torulaspora delbrueckii. Kluyveromyces marxianus, Kazachstania unispora and Saccharomyces cerevisiae were the dominant species present in this traditional fermented dairy product. This study is the first to identify the yeast communities associated with Koumiss in China. The results enrich our knowledge of yeast in Koumiss, give us a more complete picture of the microbial diversity in Koumiss and can be used to promote the development of the local dairy industry. PMID:22608237

Mu, Zhishen; Yang, XuJin; Yuan, Hongli

2012-09-01

360

Yeast Methylotrophy: Metabolism, Gene Regulation and Peroxisome Homeostasis  

PubMed Central

Eukaryotic methylotrophs, which are able to obtain all the carbon and energy needed for growth from methanol, are restricted to a limited number of yeast species. When these yeasts are grown on methanol as the sole carbon and energy source, the enzymes involved in methanol metabolism are strongly induced, and the membrane-bound organelles, peroxisomes, which contain key enzymes of methanol metabolism, proliferate massively. These features have made methylotrophic yeasts attractive hosts for the production of heterologous proteins and useful model organisms for the study of peroxisome biogenesis and degradation. In this paper, we describe recent insights into the molecular basis of yeast methylotrophy. PMID:21754936

Yurimoto, Hiroya; Oku, Masahide; Sakai, Yasuyoshi

2011-01-01

361

Variation in yeast mitochondrial activity associated with asci.  

PubMed

An increase in mitochondrial membrane potential (DeltaPsim) and mitochondrially produced 3-hydroxy (3-OH) oxylipins was experienced in asci of the nonfermentative yeasts Galactomyces reessii and Lipomyces starkeyi and the fermentative yeasts Pichia farinosa and Schizosaccharomyces octosporus. Strikingly, asci of Zygosaccharomyces bailii showed no increase in mitochondrial activity (DeltaPsim and oxylipin production). As expected, oxygen deprivation only inhibited ascus formation in those yeasts with increased ascus mitochondrial activity. We conclude that ascus formation in yeasts is not always dependent on mitochondrial activity. In this case, fermentation may provide enough energy for ascus formation in Z. bailii. PMID:18641699

Swart, Chantel W; van Wyk, Pieter W J; Pohl, Carolina H; Kock, Johan L F

2008-07-01

362

[Biotherapeutic use of yeasts--importance of probiotic products].  

PubMed

Besides their important biotechnological and industrial applications, yeasts have been used during the last years, in obtaining probiotic products, along with lactic acid bacteria and various enzymes. Our study deals with some aspects regarding the use of yeasts as animal and human probiotics, and their possible mechanisms of action. Also, we present information on probiotic products synthesized by international and national companies. Finally, there are described future prospective of research concerning the applications of recombinant yeast strains as basis for obtaining new bio-drugs. In conclusion, the data comprised in this paper, presents an interesting argument for using yeasts as biotherapeutic agents, an alternative to conventional treatments. PMID:19241999

Ghindea, Raluca; Csutak, Ortansa; Stoica, Ileana; Vassu, Tatiana

2008-01-01

363

Effect of fungicides on epiphytic yeasts associated with strawberry  

PubMed Central

We studied the effect of two commonly used fungicides on the epiphytic yeast community of strawberry. Greenhouse and field experiments were conducted applying Switch (cyprodinil plus fludioxonil) or Signum (boscalid plus pyraclostrobin) to strawberry plants. Yeasts on leaves and fruits were assessed on treated and untreated plants at several time points via plating and denaturing gradient gel electrophoresis (DGGE) analysis. The yeast counts on plates of the treated plants were similar to the control plants. Unripe fruits had 10 times larger yeast concentrations than ripe fruits or leaves. Some dominant yeast types were isolated and in vitro tests showed that they were at least 10 times less sensitive to Switch and Signum as compared with two important fungal strawberry pathogens Botrytis cinerea and Colletotrichum acutatum, which are the targets for the fungicide control. DGGE analysis showed that the applied fungicides had no effect on the composition of the yeast communities, while the growing system, strawberry tissue, and sampling time did affect the yeast communities. The yeast species most commonly identified were Cryptococcus, Rhodotorula, and Sporobolomyces. These results point toward the potential applicability of natural occurring yeast antagonists into an integrated disease control strategy for strawberry diseases.

Debode, Jane; Van Hemelrijck, Wendy; Creemers, Piet; Maes, Martine

2013-01-01

364

Resistance to heavy metals by some Nigerian yeast strains.  

PubMed

The heavy metal resistance of yeasts isolated from sugary substrates such as orange, palm wine and pineapple and identified as Saccharomyces carlsbergensis and S. cerevisiae was studied. The yeast isolates were tested against different concentrations of cadmium, copper, manganese, silver and zinc salts ranging from 1 to 20 mmol/L. Local yeasts showed resistance to 3-15 mmol/L cadmium, 18-20 copper, 16-20 manganese, 1-9 silver and 16-19 for zinc. The significance of the results is discussed in relation to the effects of heavy metals on growth of microorganisms and selection of yeasts for the brewing industry in Nigeria. PMID:8112693

Olasupo, N A; Scott-Emuakpor, M B; Ogunshola, R A

1993-01-01

365

Artificial Cellulosomes and Arsenic Cleanup: From Single Cell Programming to Synthetic Yeast Consortium  

E-print Network

al. , 2009). Yeast cells in fermentation media were countedthe bottle stopper. Yeast cells in fermentation media wereYeast surface display of trifunctional minicellulosomes for simultaneous saccharification and fermentation

Tsai, Shen-Long

2011-01-01

366

Intestinal mucosal mast cells from rats infected with Nippostrongylus brasiliensis contain protease-resistant chondroitin sulfate di-B proteoglycans  

SciTech Connect

Rats infected with the helminth Nippostrongylus brasiliensis were injected i.p. with 2 mCi of (/sup 35/S) sulfate on days 13, 15, 17, and 19 after infection. The intestines were removed from animals on day 20 or 21 after infection, the intestinal cells were obtained by collagenase treatment and mechanical dispersion of the tissue, and the /sup 35/S-labeled mucosal mast cells (MMC) were enriched to 60 to 65% purity by Percoll centrifugation. The isolated proteoglycans were of approx. 150,000 m.w., were resistant to pronase degradation, and contained highly sulfated chondroitin sulfate side chains. The presence in normal mammalian cells of chondroitin sulfate proteoglycans that contain a high percentage of the unusual disulfated di-B disaccharide has not been previously reported. The rat intestinal MMC proteoglycans are the first chondroitin sulfate proteoglycans that have been isolated from an enriched populations of normal mast cells. They are homologous to the chondroitin sulfate-rich proteoglycans of the transformed rat basophilic leumekia-1 cell and the cultured interleukin 3-dependent mouse bone marrow-derived mast cell, in that these chondroitin sulfate proteoglycans are all highly sulfated, protease-resistant proteoglycans.

Stevens, R.L.; Lee, T.D.G.; Seldin, D.C.; Austen, K.F.; Befus, A.D.; Bienenstock, J.

1986-07-01

367

Accumulation of a bioactive triterpene saponin fraction of Quillaja brasiliensis leaves is associated with abiotic and biotic stresses.  

PubMed

The saponins from leaves of Quillaja brasiliensis, a native species from Southern Brazil, show structural and functional similarities to those of Quillaja saponaria barks, which are currently used as adjuvants in vaccine formulations. The accumulation patterns of an immunoadjuvant fraction of leaf triterpene saponins (QB-90) in response to stress factors were examined, aiming at understanding the regulation of accumulation of these metabolites. The content of QB-90 in leaf disks was significantly increased by application of different osmotic stress agents, such as sorbitol, sodium chloride and polyethylene glycol in isosmotic concentrations. Higher yields of bioactive saponins were also observed upon exposure to salicylic acid, jasmonic acid, ultrasound and UV-C light. Experiments with shoots indicated a significant increase in QB-90 yields with moderate increases in white light irradiance and by mechanical damage applied to leaves. The increased accumulation of these terpenes may be part of a defense response. The results herein described may contribute to further advance knowledge on the regulation of accumulation of bioactive saponins, and at defining strategies to improve yields of these useful metabolites. PMID:23474431

de Costa, Fernanda; Yendo, Anna Carolina Alves; Fleck, Juliane Deise; Gosmann, Grace; Fett-Neto, Arthur Germano

2013-05-01

368

Purification and Characterization of Two Major Lectins from Araucaria brasiliensis syn. Araucaria angustifolia Seeds (Pinh?o) 1  

PubMed Central

Two major lectins (lectin I and lectin II) were purified to homogeneity from the seeds of Araucaria brasiliensis (Gymnospermae). The purity of the lectins was confirmed by polyacrylamide gel electrophoresis, isoelectric focusing, and high performance liquid chromatography. They are glycoproteins in nature containing 6.3 and 2.9%, respectively, of neutral sugar and have absorption coefficients of 3.8 and 4.7, respectively, at 280 nanometers. The molecular weights of both lectins obtained by gel filtration on Sephacryl S-400 were equal: 200,000. After dissociation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, molecular weights were 20,000 and 34,000, respectively, for lectin I and lectin II, suggesting they are decameric and hexameric in nature. The amino acid composition of both lectins showed little difference, but both had high amounts of acidic amino acids and lacked methionine in their molecule. The carbohydrate binding specificity of lectins was directed towards mannose, glucose, and their oligomers. High inhibitory activity was also found with thyroglobulin. The erythroagglutinating activity of the lectins was enhanced in the presence of high-molecular-weight substances both at 37 and 4°C. Divalent cations do not appear to be essential for activity. They maintained their agglutinating activity over a broad but different range of pH: 5.5 to 7.5 and 6.5 to 7.5, respectively. Both lectins agglutinated erythrocytes of human ABO blood types equally well. ImagesFigure 2Figure 3 PMID:16668523

Datta, Pradip K.; Figueroa, Maria O. D. C. R.; Lajolo, Franco M.

1991-01-01

369

Genome-wide analysis of microRNAs in rubber tree (Hevea brasiliensis L.) using high throughput sequencing  

PubMed Central

MicroRNAs (miRNAs) are short RNAs with essential roles in gene regulation in various organisms including higher plants. In contrast to the vast information on miRNAs from many economically important plants, almost nothing has been reported on the identification or analysis of miRNAs from rubber tree (Hevea brasiliensis L.), the most important natural rubber-producing crop. To identify miRNAs and their target genes in rubber tree, high throughput sequencing combined with a computational approach was performed. Four small RNA libraries were constructed for deep sequencing from mature and young leaves of two rubber tree clones, PB 260 and PB 217, which provide high and low latex yield, respectively. 115 miRNAs belonging to 56 known miRNA families were identified, and northern hybridization validated miRNA expression and revealed developmental stage-dependent and clone-specific expression for some miRNAs. We took advantage of the newly released rubber tree genome assembly and predicted 20 novel miRNAs. Further computational analysis uncovered potential targets of the known and novel miRNAs. Predicted target genes included not only transcription factors but also genes involved in various biological processes including stress responses, primary and secondary metabolism, and signal transduction. In particular, genes with roles in rubber biosynthesis are predicted targets of miRNAs. This study provides a basic catalog of miRNAs and their targets in rubber tree to facilitate future improvement and exploitation of rubber tree. PMID:22407387

Lertpanyasampatha, Manassawe; Gao, Lei; Kongsawadworakul, Panida; Viboonjun, Unchera; Chrestin, Herve; Liu, Renyi

2012-01-01

370

Kinetic studies on the enzyme (S)-hydroxynitrile lyase from hevea brasiliensis using initial rate methods and progress curve analysis  

PubMed

(S)-Hydroxynitrile lyase (EC 4.1.2.39) from Hevea brasiliensis(rubber tree) catalyzes the reversible cleavage of cyanohydrins to aldehydes or ketones and prussic acid (HCN). Enzyme kinetics in both directions was studied on a model system with mandelonitrile, benzaldehyde, and HCN using two different methods-initial rate measurements and progress curve analysis. To discriminate between possible mechanisms with the initial rate method, product inhibition was studied. Benzaldehyde acts as a linear competitive inhibitor against mandelonitrile whereas HCN shows S-linear I-parabolic mixed-type inhibition. These results indicate an Ordered Uni Bi mechanism with the formation of a dead-end complex of enzyme, (S)-mandelonitrile and HCN. Prussic acid is the first product released from the enzyme followed by benzaldehyde. For progress curve analysis, a kinetic model of an Ordered Uni Bi mechanism including a dead-end complex, enzyme inactivation, and the chemical parallel reaction was set up, which described the experimental values very well. From the reaction rates obtained the kinetic constants were calculated and compared with the ones obtained from the initial rate method. Good agreement could be achieved between the two methods supporting the suggested mechanism. Copyright 1999 John Wiley & Sons, Inc. PMID:10099509

Bauer; Griengl; Steiner

1999-01-01

371

Comparison of the Quantum II, API Yeast Ident, and AutoMicrobic systems for identification of clinical yeast isolates.  

PubMed Central

The Quantum II Yeast Identification System (Abbott Laboratories) is a microprocessor-based spectrophotometric system for identification of clinical yeast isolates within 24 h. We compared the Quantum II system with the API Yeast Ident (Analytab Products) and the AutoMicrobic System Yeast Biochemical Card (AMS-YBC; Vitek Systems, Inc.) for the identification of 221 clinical yeast isolates, including 120 common clinical isolates (Candida albicans, C. tropicalis, C. parapsilosis, Torulopsis glabrata, and Cryptococcus neoformans) and 101 relatively uncommon clinical isolates. The API 20C (Analytab) was used as the reference system. The Quantum II and AMS-YBC systems correctly identified 181 (82%) and 184 (83%) isolates, respectively, whereas the Yeast Ident system correctly identified 132 (60%) isolates. Of the 120 common clinical isolates, 113 (94%) were correctly identified by Quantum II, 103 (86%) were correctly identified by AMS-YBC, and 83 (69%) were correctly identified by Yeast Ident. Of the 101 uncommon clinical isolates tested, 68 (67%) were correctly identified by Quantum II, 81 (80%) were correctly identified by AMS-YBC, and 49 (49%) were correctly identified by Yeast Ident. The overall accuracy of the Quantum II, AMS-YBC, and API Yeast Ident was not sufficient to recommend any of these systems for routine use in the clinical microbiology laboratory without substantial expansion of the respective data bases. PMID:3182994

Pfaller, M A; Preston, T; Bale, M; Koontz, F P; Body, B A

1988-01-01

372

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.

1993-09-01

373

Yeast through the ages: A statistical analysis of genetic changes in aging yeast  

E-print Network

for a given yeast sample all the genetic information is isolated to one cell. To study the genetic effects', 6420 spots contained genetic information of interest, the remaining spots were either control genes or spots on the array that were empty of genetic information. Throughout the paper, we'll refer to 6420

Hardin, Jo

374

Genetically modified yeast species, and fermentation processes using genetically modified yeast  

DOEpatents

Yeast cells are transformed with an exogenous xylose isomerase gene. Additional genetic modifications enhance the ability of the transformed cells to ferment xylose to ethanol or other desired fermentation products. Those modifications include deletion of non-specific or specific aldose reductase gene(s), deletion of xylitol dehydrogenase gene(s) and/or overexpression of xylulokinase.

Rajgarhia, Vineet; Koivuranta, Kari; Penttila, Merja; Ilmen, Marja; Suominen, Pirkko; Aristidou, Aristos; Miller, Christopher Kenneth; Olson, Stacey; Ruohonen, Laura

2013-05-14

375

Genetically modified yeast species and fermentation processes using genetically modified yeast  

DOEpatents

Yeast cells are transformed with an exogenous xylose isomerase gene. Additional genetic modifications enhance the ability of the transformed cells to ferment xylose to ethanol or other desired fermentation products. Those modifications', include deletion of non-specific or specific aldose reductase gene(s), deletion of xylitol dehydrogenase gene(s) and/or overexpression of xylulokinase.

Rajgarhia, Vineet (Kingsport, TN); Koivuranta, Kari (Helsinki, FI); Penttila, Merja (Helsinki, FI); Ilmen, Marja (Helsinki, FI); Suominen, Pirkko (Maple Grove, MN); Aristidou, Aristos (Maple Grove, MN); Miller, Christopher Kenneth (Cottage Grove, MN); Olson, Stacey (St. Bonifacius, MN); Ruohonen, Laura (Helsinki, FI)

2011-05-17

376

Genetic Influences on Translation in Yeast  

PubMed Central

Heritable differences in gene expression between individuals are an important source of phenotypic variation. The question of how closely the effects of genetic variation on protein levels mirror those on mRNA levels remains open. Here, we addressed this question by using ribosome profiling to examine how genetic differences between two strains of the yeast S. cerevisiae affect translation. Strain differences in translation were observed for hundreds of genes. Allele specific measurements in the diploid hybrid between the two strains revealed roughly half as many cis-acting effects on translation as were observed for mRNA levels. In both the parents and the hybrid, most effects on translation were of small magnitude, such that the direction of an mRNA difference was typically reflected in a concordant footprint difference. The relative importance of cis and trans acting variation on footprint levels was similar to that for mRNA levels. There was a tendency for translation to cause larger footprint differences than expected given the respective mRNA differences. This is in contrast to translational differences between yeast species that have been reported to more often oppose than reinforce mRNA differences. Finally, we catalogued instances of premature translation termination in the two yeast strains and also found several instances where erroneous reference gene annotations lead to apparent nonsense mutations that in fact reside outside of the translated gene body. Overall, genetic influences on translation subtly modulate gene expression differences, and translation does not create strong discrepancies between genetic influences on mRNA and protein levels. PMID:25340754

Albert, Frank W.; Muzzey, Dale; Weissman, Jonathan S.; Kruglyak, Leonid

2014-01-01

377

Visualization of yeast cells by electron microscopy.  

PubMed

In the 1970s, hydrocarbon or methanol utilizable yeasts were considered as a material for foods and ethanol production. During the course of studies into the physiology of yeasts, we found that these systems provide a suitable model for the biogenesis and ultrastructure research of microbodies (peroxisomes). Microbodies of hydrocarbon utilizing Candida tropicalis multiply profusely from the preexisting microbody. ? oxidation enzymes in the microbody were determined by means of immunoelectron microscopy. We examined the ultrastructure of Candida boidinii microbodies grown on methanol, and found a composite crystalloid of two enzymes, alcohol oxidase and catalase, by analyzing using the optical diffraction and filtering technique and computer simulation. We established methods for preparing the protoplasts of Schizosaccharomyces pombe and conditions for the complete regeneration of the cell wall. The dynamic process of cell wall formation was clarified through our study of the protoplasts, using an improved ultra high resolution (UHR) FESEM S-900 and an S-900LV. It was found that ?-1,3-glucan, ?-1,6-glucan and ?-1,3-glucan, as well as ?-galactomannan, are ingredients of the cell wall. The process of septum formation during cell division was examined after cryo-fixation by high pressure freezing (HPF). It was also found that ?-1,3- and ?-1,3-glucans were located in the invaginating nascent septum, and later, highly branched ?-1,6-glucan also appeared on the second septum. The micro-sampling method, using a focused ion beam (FIB), has been applied to our yeast cell wall research. A combination of FIB and scanning transmission electron microscopy is useful in constructing 3D images and analyzing the molecular architecture of cells, as well as for electron tomography of thick sections of biological specimens. PMID:23231852

Osumi, Masako

2012-01-01

378

Crystal structure of yeast Sco1  

SciTech Connect

The Sco family of proteins are involved in the assembly of the dinuclear CuA site in cytochrome c oxidase (COX), the terminal enzyme in aerobic respiration. These proteins, which are found in both eukaryotes and prokaryotes, are characterized by a conserved CXXXC sequence motif that binds copper ions and that has also been proposed to perform a thiol:disulfide oxidoreductase function. The crystal structures of Saccharomyces cerevisiae apo Sco1 (apo-ySco1) and Sco1 in the presence of copper ions (Cu-ySco1) were determined to 1.8- and 2.3-{angstrom} resolutions, respectively. Yeast Sco1 exhibits a thioredoxin-like fold, similar to that observed for human Sco1 and a homolog from Bacillus subtilis. The Cu-ySco1 structure, obtained by soaking apo-ySco1 crystals in copper ions, reveals an unexpected copper-binding site involving Cys181 and Cys216, cysteine residues present in ySco1 but not in other homologs. The conserved CXXXC cysteines, Cys148 and Cys152, can undergo redox chemistry in the crystal. An essential histidine residue, His239, is located on a highly flexible loop, denoted the Sco loop, and can adopt positions proximal to both pairs of cysteines. Interactions between ySco1 and its partner proteins yeast Cox17 and yeast COX2 are likely to occur via complementary electrostatic surfaces. This high-resolution model of a eukaryotic Sco protein provides new insight into Sco copper binding and function.

Abajian, Carnie; Rosenzweig, Amy C. (NWU)

2010-03-05

379

Osmotic Stress Signaling and Osmoadaptation in Yeasts  

PubMed Central

The ability to adapt to altered availability of free water is a fundamental property of living cells. The principles underlying osmoadaptation are well conserved. The yeast Saccharomyces cerevisiae is an excellent model system with which to study the molecular biology and physiology of osmoadaptation. Upon a shift to high osmolarity, yeast cells rapidly stimulate a mitogen-activated protein (MAP) kinase cascade, the high-osmolarity glycerol (HOG) pathway, which orchestrates part of the transcriptional response. The dynamic operation of the HOG pathway has been well studied, and similar osmosensing pathways exist in other eukaryotes. Protein kinase A, which seems to mediate a response to diverse stress conditions, is also involved in the transcriptional response program. Expression changes after a shift to high osmolarity aim at adjusting metabolism and the production of cellular protectants. Accumulation of the osmolyte glycerol, which is also controlled by altering transmembrane glycerol transport, is of central importance. Upon a shift from high to low osmolarity, yeast cells stimulate a different MAP kinase cascade, the cell integrity pathway. The transcriptional program upon hypo-osmotic shock seems to aim at adjusting cell surface properties. Rapid export of glycerol is an important event in adaptation to low osmolarity. Osmoadaptation, adjustment of cell surface properties, and the control of cell morphogenesis, growth, and proliferation are highly coordinated processes. The Skn7p response regulator may be involved in coordinating these events. An integrated understanding of osmoadaptation requires not only knowledge of the function of many uncharacterized genes but also further insight into the time line of events, their interdependence, their dynamics, and their spatial organization as well as the importance of subtle effects. PMID:12040128

Hohmann, Stefan

2002-01-01

380

How does yeast respond to pressure?  

PubMed

The brewing and baking yeast Saccharomyces cerevisiae has been used as a model for stress response studies of eukaryotic cells. In this review we focus on the effect of high hydrostatic pressure (HHP) on S. cerevisiae. HHP exerts a broad effect on yeast cells characteristic of common stresses, mainly associated with protein alteration and lipid bilayer phase transition. Like most stresses, pressure induces cell cycle arrest. Below 50 MPa (500 atm) yeast cell morphology is unaffected whereas above 220 MPa wild-type cells are killed. S. cerevisiae cells can acquire barotolerance if they are pretreated with a sublethal stress due to temperature, ethanol, hydrogen peroxide, or pressure. Nevertheless, pressure only leads to protection against severe stress if, after pressure pretreatment, the cells are also re-incubated at room pressure. We attribute this effect to the inhibition of the protein synthesis apparatus under HHP. The global genome expression analysis of S. cerevisiae cells submitted to HHP revealed a stress response profile. The majority of the up-regulated genes are involved in stress defense and carbohydrate metabolism while most repressed genes belong to the cell cycle progression and protein synthesis categories. However, the signaling pathway involved in the pressure response is still to be elucidated. Nitric oxide, a signaling molecule involved in the regulation of a large number of cellular functions, confers baroprotection. Furthermore, S. cerevisiae cells in the early exponential phase submitted to 50-MPa pressure show induction of the expression level of the nitric oxide synthase inducible isoform. As pressure becomes an important biotechnological tool, studies concerning this kind of stress in microorganisms are imperative. PMID:16082465

Fernandes, P M B

2005-08-01

381

Kinetic studies on the yeast Phaffia rhodozyma.  

PubMed

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

1995-01-01

382

Modification of yeast ribosomal proteins. Methylation.  

PubMed Central

Two-dimensional polyacrylamide-gel electrophoretic analysis of yeast ribosomal proteins uniformly labelled in vivo with [methyl-3H]methionine and [1-14C]methionine revealed that four ribosomal proteins are methylated, i.e. proteins S31, S32, L15 and L41. Lysine and arginine appear to be the predominant acceptors of the methyl groups. The degree of methylation ranges from 0.09 to 0.20 methyl group per modified ribosomal protein species. PMID:367366

Kruiswijk, T; Kunst, A; Planta, R J; Mager, W H

1978-01-01

383

Multiple dextranases from the yeast Lipomyces starkeyi  

Microsoft Academic Search

The soil yeast Lipomyces starkeyi (NCYC 1436) secretes dextranase activity into the growth medium. Resolution of a dextranase-active protein fraction by SDS-PAGE\\u000a produced three protein bands, of 66 kDa, 68 kDa and 78 kDa, and isoelectric focusing of the same fraction resulted in seven\\u000a protein bands, of pIs 3.50, 3.85, 4.20, 4.80, 4.85, 5.00 and 5.30. Dextranase activity was demonstrated for all the

Stefan H. Millson; Ivor Howell Evans

2007-01-01

384

Ascorbic acid specific utilization by some yeasts.  

PubMed

One hundred and eighty strains of yeasts belonging to 17 genus and 53 species were screened for their ability to grow on ascorbic acid and iso-ascorbic acid as the sole carbon source. Most of the tested strains (157) were unable to grow on either compound. Strains of seven species of the genus Cryptococcus, of two Candida species, of Filobasidiella neoformans, Trichosporon cutaneum, Lipomyces starkeyi, Hansenula capsulata, and one strain of Aureobasidium pullulans were able to grow on ascorbic as well as on iso-ascorbic acid. Conversely, four strains of Aureobasidium pullulans, Candida blankii, and Cryptococcus dimennae could use only ascorbic acid for growth. PMID:3779527

Costamagna, L; Rosi, I; Garuccio, I; Arrigoni, O

1986-09-01

385

Fanconi-like crosslink repair in yeast  

PubMed Central

Interstrand crosslinks covalently link complementary DNA strands, block replication and transcription, and can trigger cell death. In eukaryotic systems several pathways, including the Fanconi Anemia pathway, are involved in repairing interstrand crosslinks, but their precise mechanisms remain enigmatic. The lack of functional homologs in simpler model organisms has significantly hampered progress in this field. Two recent studies have finally identified a Fanconi-like interstrand crosslink repair pathway in yeast. Future studies in this simplistic model organism promise to greatly improve our basic understanding of complex interstrand crosslink repair pathways like the Fanconi pathway. PMID:23062727

2012-01-01

386

Molecular Complementarity of Yeast Glycoprotein Mating Factors  

PubMed Central

Cell fusion between opposite mating types 5 and 21 of the yeast Hansenula wingei is initiated by a strong sexual agglutination reaction. The mating factors responsible for the specificity of cellular recognition are complementary glycoproteins which form a physical complex in vitro. The complex is assayed by recovery of agglutination activity of the multivalent 5-factor after the univalent 21-factor has been inactivated by treatment of the complex with alkali. The 5-factor·21-factor complex, purified on Sepharose 6B, is large (several million daltons) and heterogeneous. The three peaks of 5-factor activity contain a number of combining sites proportional to molecular size. PMID:4521055

Crandall, Marjorie; Lawrence, Lawrence M.; Saunders, Robert M.

1974-01-01

387

Molecular complementarity of yeast glycoprotein mating factors.  

PubMed

Cell fusion between opposite mating types 5 and 21 of the yeast Hansenula wingei is initiated by a strong sexual agglutination reaction. The mating factors responsible for the specificity of cellular recognition are complementary glycoproteins which form a physical complex in vitro. The complex is assayed by recovery of agglutination activity of the multivalent 5-factor after the univalent 21-factor has been inactivated by treatment of the complex with alkali. The 5-factor.21-factor complex, purified on Sepharose 6B, is large (several million daltons) and heterogeneous. The three peaks of 5-factor activity contain a number of combining sites proportional to molecular size. PMID:4521055

Crandall, M; Lawrence, L M; Saunders, R M

1974-01-01

388

Exploring the Ubiquitin-Proteasome Protein Degradation Pathway in Yeast  

ERIC Educational Resources Information Center

This article describes an undergraduate biochemistry laboratory investigating the ubiquitin-proteasome pathway in yeast. In this exercise, the enzyme beta-galactosidase (beta-gal) is expressed in yeast under the control of a stress response promoter. Following exposure to heat stress to induce beta-gal expression, cycloheximide is added to halt…

Will, Tamara J.; McWatters, Melissa K.; McQuade, Kristi L.

2006-01-01

389

Medical significance of the so-called black yeasts  

Microsoft Academic Search

Infections caused by the black yeasts (leveduras pretas) are reviewed with respect to their clinical manifestations, classification under the umbrella term, phaeohyphomycosis, and differentiation from chromoblastomycosis. Data on the prevalence of black yeasts submitted to a national reference diagnostic center are provided. Cases of phaeohyphomycosis caused by Aureobasidium pullulans, Exophiala jeanselmei, E. moniliae, E. spinifera, Phaeoannelomyces werneckii, Phaeosclera dematioirles, Sarcinomyces

T. Matsumoto; A. A. Padhye; L. Ajello

1987-01-01

390

tRNA genes and retroelements in the yeast genome.  

PubMed Central

A survey of tRNA genes and retroelements (Ty) in the genome of the yeast Saccharomyces cerevisiae is presented. Aspects of genomic organization and evolution of these genetic entities and their interplay are discussed. Attention is also given to the relationship between tRNA gene multiplicity and codon selection in yeast and the role of Ty elements. PMID:9443958

Hani, J; Feldmann, H

1998-01-01

391

Yeast activator proteins and stress response: an overview  

Microsoft Academic Search

Yeast, and especially Saccharomyces cerevisiae, are continuously exposed to rapid and drastic changes in their external milieu. Therefore, cells must maintain their homeostasis, which is achieved through a highly coordinated gene expression involving a plethora of transcription factors, each of them performing specific functions. Here, we discuss recent advances in our understanding of the function of the yeast activator protein

Claudina Amélia Rodrigues-Pousada; Tracy Nevitt; Regina Menezes; Dulce Azevedo; Jorge Pereira; Catarina Amaral

2004-01-01

392

Landfill Leachate Treatment by Yeast and Bacteria Based Membrane Bioreactors  

Microsoft Academic Search

Biological treatment of medium-age landfill leachate was investigated on a membrane bioreactor. The experiments were conducted in two 5-L reactors with immersed hollow fiber microfiltration membranes. One reactor was operated with a mixed bacterial culture termed as bacteria based membrane bioreactor (BMBR) while the other with mixed yeast culture termed as yeast based membrane bioreactor (YMBR). The leachate was characterized

B. Wichitsathian; S. Sindhuja; C. Visvanathan; K. H. Ahn

2004-01-01

393

Systematic Management and Analysis of Yeast Gene Expression Data  

E-print Network

Systematic Management and Analysis of Yeast Gene Expression Data John Aach, Wayne Rindone the ExpressDB database for yeast RNA expression data and loaded it with 17.5 million pieces of data reported), which exhibit increased error, on our web site http://arep.med.harvard.edu/ExpressDB. We recommend

Church, George M.

394

Starch utilization by yeasts: mutants resistant of carbon catabolite repression  

Microsoft Academic Search

Twenty-seven yeasts were screened for starch breakdown; the three with the highest rate were strains of Filobasidium capsuligenum, Lipomyces starkeyi and Schwanniomyces occidentalis. Of these, only the last gave mutants with diminished carbon catabolite repression and, hence, enhanced amylase activity. Unlike those yeasts previously reported to break down starch rapidly, these mutants had the commercially advantageous characteristic of growing only

A. Kate McCann; J. A. Barnett

1984-01-01

395

High ethanol tolerance yeast for production of ethanol  

SciTech Connect

The subject of ethanol tolerance in yeasts has been receiving considerable attention as result of renewed interest in ethanol as a fuel source. Fermentation of sugars to ethanol is being studied in our laboratory using a genetically engineered yeast strain 1400. Results are described.

Krishnan, M.S.; Tsao, G.T.; Kasthurikrishnan, N. [Purdue Univ., West Lafayette, IN (United States)] [and others

1995-12-01

396

Dynamics of Cell Shape Inheritance in Fission Yeast  

E-print Network

form one of the strongest non-covalent bonds in nature [63], whereas lectins have been extensively documented to bind yeast cell wall mannan [64]). After three washes with YES medium, cells were incubated 10 minutes in a dilution 1:500 Fission Yeast...

Abenza, Juan F.; Chessel, Anatole; Raynaud, William G.; Carazo-Salas, Rafael E.

2014-09-11

397

A virtual lab for exploring the yeast prion  

E-print Network

A virtual lab for exploring the ¢¡¤£¦¥¨§© yeast prion Jacqueline L. Whalley , Mick F. Tuite within the cell of a prion protein in yeast. The biological background to the project is outlined for this transformation process. Abnormal forms of proteins which have this infectious property and known as prion

Kent, University of

398

Yeast Sequencing Report Identification of a Candida glabrata homologue of  

E-print Network

Yeast Sequencing Report Identification of a Candida glabrata homologue of the S. cerevisiae VRG4 from the pathogenic yeast, Candida glabrata, by functional complementation of an S. cerevisiae vrg4 John Wiley & Sons, Ltd. Keywords: glycosylation; Candida glabrata; nucleotide sugar transporter; GDP

Citovsky, Vitaly

399

ORIGINAL PAPER Candida gelsemii sp. nov., a yeast  

E-print Network

ORIGINAL PAPER Candida gelsemii sp. nov., a yeast of the Metschnikowiaceae clade isolated from+Business Media B.V. 2006 Abstract A new yeast species, Candida gelsemii, is described to accommodate three of Metschnikowia and Candida species known to occur in association with nectars and bees, as well as marine inverte

Thomson, James D.

400

Inhibition of Listeria monocytogenes by Food-Borne Yeasts  

PubMed Central

Many bacteria are known to inhibit food pathogens, such as Listeria monocytogenes, by secreting a variety of bactericidal and bacteriostatic substances. In sharp contrast, it is unknown whether yeast has an inhibitory potential for the growth of pathogenic bacteria in food. A total of 404 yeasts were screened for inhibitory activity against five Listeria monocytogenes strains. Three hundred and four of these yeasts were isolated from smear-ripened cheeses. Most of the yeasts were identified by Fourier transform infrared spectroscopy. Using an agar-membrane screening assay, a fraction of approximately 4% of the 304 red smear cheese isolates clearly inhibited growth of L. monocytogenes. Furthermore, 14 out of these 304 cheese yeasts were cocultivated with L. monocytogenes WSLC 1364 on solid medium to test the antilisterial activity of yeast in direct cell contact with Listeria. All yeasts inhibited L. monocytogenes to a low degree, which is most probably due to competition for nutrients. However, one Candida intermedia strain was able to reduce the listerial cell count by 4 log units. Another four yeasts, assigned to C. intermedia (three strains) and Kluyveromyces marxianus (one strain), repressed growth of L. monocytogenes by 3 log units. Inhibition of L. monocytogenes was clearly pronounced in the cocultivation assay, which simulates the conditions and contamination rates present on smear cheese surfaces. We found no evidence that the unknown inhibitory molecule is able to diffuse through soft agar. PMID:16391059

Goerges, Stefanie; Aigner, Ulrike; Silakowski, Barbara; Scherer, Siegfried

2006-01-01

401

Improving industrial yeast strains: exploiting natural and artificial diversity.  

PubMed

Yeasts have been used for thousands of years to make fermented foods and beverages, such as beer, wine, sake, and bread. However, the choice for a particular yeast strain or species for a specific industrial application is often based on historical, rather than scientific grounds. Moreover, new biotechnological yeast applications, such as the production of second-generation biofuels, confront yeast with environments and challenges that differ from those encountered in traditional food fermentations. Together, this implies that there are interesting opportunities to isolate or generate yeast variants that perform better than the currently used strains. Here, we discuss the different strategies of strain selection and improvement available for both conventional and nonconventional yeasts. Exploiting the existing natural diversity and using techniques such as mutagenesis, protoplast fusion, breeding, genome shuffling and directed evolution to generate artificial diversity, or the use of genetic modification strategies to alter traits in a more targeted way, have led to the selection of superior industrial yeasts. Furthermore, recent technological advances allowed the development of high-throughput techniques, such as 'global transcription machinery engineering' (gTME), to induce genetic variation, providing a new source of yeast genetic diversity. PMID:24724938

Steensels, Jan; Snoek, Tim; Meersman, Esther; Nicolino, Martina Picca; Voordeckers, Karin; Verstrepen, Kevin J

2014-09-01

402

Fuel Ethanol Production from Molasses by Some Indigenous Yeast Isolates  

Microsoft Academic Search

In view of the anticipated shortage of the traditional supplies of fossil fuels there is a great deal of interest in production of ethanol as an alternative biofuel in recent years. The present report describes the search for potential yeast isolates from various ferments capable of producing ethanol. Twenty-one indigenous yeast isolates were recovered from various sources. Thirteen of them

Sabera Hasibe Sheela; M Firoz Ahmed; Donald James Gomes

2008-01-01

403

BIOCONTROL ACTIVITY OF ANTAGONISTIC YEASTS AGAINST PENICILLIUM EXPANSUM ON APPLE  

Microsoft Academic Search

SUMMARY Penicillium expansum causes severe rots on apple fruit during storage and shelf life. Aiming at the devel- opment of new antagonistic yeast active in controlling postharvest pathogens of fruit, several isolates were ob- tained from fig (Ficus carica) and cactus pear (Opuntia ficus-indica) grown in untreated orchards in Northern Sardinia (Italy). Two yeast strains of Candida guiller- mondii were

B. Scherm; G. Ortu; A. Muzzu; M. Budroni; G. Arras; Q. Migheli

404

Analysis of the RNA Content of the Yeast "Saccharomyces Cerevisiae"  

ERIC Educational Resources Information Center

In this article, the authors describe an interconnected set of relatively simple laboratory experiments in which students determine the RNA content of yeast cells and use agarose gel electrophoresis to separate and analyze the major species of cellular RNA. This set of experiments focuses on RNAs from the yeast "Saccharomyces cerevisiae", a…

Deutch, Charles E.; Marshall, Pamela A.

2008-01-01

405

Tolerance of budding yeast Saccharomyces cerevisiae to ultra high pressure  

NASA Astrophysics Data System (ADS)

Our studies on the tolerance of plants and animals against very high pressure of several GPa have been extended to a smaller sized fungus, the budding yeast Saccharomyces cerevisiae. Several pieces of budding yeast (dry yeast) were sealed in a small teflon capsule with a liquid pressure medium fluorinate, and exposed to 7.5 GPa by using a cubic anvil press. The pressure was kept constant for various duration of time from 2 to 24 h. After the pressure was released, the specimens were brought out from the teflon capsule, and they were cultivated on a potato dextrose agar. It was found that the budding yeast exposed to 7.5 GPa for up to 6 h showed multiplication. However, those exposed to 7.5 GPa for longer than 12 h were found dead. The high pressure tolerance of budding yeast is a little weaker than that of tardigrades.

Shibata, M.; Torigoe, M.; Matsumoto, Y.; Yamamoto, M.; Takizawa, N.; Hada, Y.; Mori, Y.; Takarabe, K.; Ono, F.

2014-05-01

406

Yeast cell factories for fine chemical and API production  

PubMed Central

This review gives an overview of different yeast strains and enzyme classes involved in yeast whole-cell biotransformations. A focus was put on the synthesis of compounds for fine chemical and API (= active pharmaceutical ingredient) production employing single or only few-step enzymatic reactions. Accounting for recent success stories in metabolic engineering, the construction and use of synthetic pathways was also highlighted. Examples from academia and industry and advances in the field of designed yeast strain construction demonstrate the broad significance of yeast whole-cell applications. In addition to Saccharomyces cerevisiae, alternative yeast whole-cell biocatalysts are discussed such as Candida sp., Cryptococcus sp., Geotrichum sp., Issatchenkia sp., Kloeckera sp., Kluyveromyces sp., Pichia sp. (including Hansenula polymorpha = P. angusta), Rhodotorula sp., Rhodosporidium sp., alternative Saccharomyces sp., Schizosaccharomyces pombe, Torulopsis sp., Trichosporon sp., Trigonopsis variabilis, Yarrowia lipolytica and Zygosaccharomyces rouxii. PMID:18684335

Pscheidt, Beate; Glieder, Anton

2008-01-01

407

Stationary phase in the yeast Saccharomyces cerevisiae.  

PubMed Central

Growth and proliferation of microorganisms such as the yeast Saccharomyces cerevisiae are controlled in part by the availability of nutrients. When proliferating yeast cells exhaust available nutrients, they enter a stationary phase characterized by cell cycle arrest and specific physiological, biochemical, and morphological changes. These changes include thickening of the cell wall, accumulation of reserve carbohydrates, and acquisition of thermotolerance. Recent characterization of mutant cells that are conditionally defective only for the resumption of proliferation from stationary phase provides evidence that stationary phase is a unique developmental state. Strains with mutations affecting entry into and survival during stationary phase have also been isolated, and the mutations have been shown to affect at least seven different cellular processes: (i) signal transduction, (ii) protein synthesis, (iii) protein N-terminal acetylation, (iv) protein turnover, (v) protein secretion, (vi) membrane biosynthesis, and (vii) cell polarity. The exact nature of the relationship between these processes and survival during stationary phase remains to be elucidated. We propose that cell cycle arrest coordinated with the ability to remain viable in the absence of additional nutrients provides a good operational definition of starvation-induced stationary phase. PMID:8393130

Werner-Washburne, M; Braun, E; Johnston, G C; Singer, R A

1993-01-01

408

Yeast lipid metabolism at a glance.  

PubMed

During the last decades, lipids have gained much attention due to their involvement in health and disease. Lipids are required for the formation of membranes and contribute to many different processes such as cell signaling, energy supply, and cell death. Various organelles such as the endoplasmic reticulum, mitochondria, peroxisomes, and lipid droplets are involved in lipid metabolism. The yeast Saccharomyces cerevisiae has become a reliable model organism to study biochemistry, molecular biology, and cell biology of lipids. The availability of mutants bearing defects in lipid metabolic pathways and the ease of manipulation by culture conditions facilitated these investigations. Here, we summarize the current knowledge about lipid metabolism in yeast. We grouped this large topic into three sections dealing with (1) fatty acids; (2) membrane lipids; and (3) storage lipids. Fatty acids serve as building blocks for the synthesis of membrane lipids (phospholipids, sphingolipids) and storage lipids (triacylglycerols, steryl esters). Phospholipids, sterols, and sphingolipids are essential components of cellular membranes. Recent investigations addressing lipid synthesis, degradation, and storage as well as regulatory aspects are presented. The role of enzymes governing important steps of the different lipid metabolic pathways is described. Finally, the link between lipid metabolic and dynamic processes is discussed. PMID:24520995

Klug, Lisa; Daum, Günther

2014-05-01

409

Copper exposure effects on yeast mitochondrial proteome.  

PubMed

Mitochondria play an important role on the entire cellular copper homeostatic mechanisms. Alteration of cellular copper levels may thus influence mitochondrial proteome and its investigation represents an important contribution to the general understanding of copper-related cellular effects. In these study we have performed an organelle targeted proteomic investigation focusing our attention on the effect of non-lethal 1mM copper concentration on Saccharomyces cerevisiae mitochondrial proteome. Functional copper effects on yeast mitochondrial proteome were evaluated by using both 2D electrophoresis (2-DE) and liquid chromatography coupled with tandem mass spectrometry. Proteomic data have been then analyzed by different unsupervised meta-analysis approaches that highlight the impairment of mitochondrial functions and the activation of oxidative stress response. Interestingly, our data have shown that stress response generated by 1mM copper treatment determines the activation of S. cerevisiae survival pathway. To investigate these findings we have treated yeast cells responsiveness to copper with hydrogen peroxide and observed a protective role of this metal. These results are suggestive of a copper role in the protection from oxidative stress possibly due to the activation of mechanisms involved in cellular survival and growth. PMID:21549866

Banci, Lucia; Bertini, Ivano; Ciofi-Baffoni, Simone; D'Alessandro, Annamaria; Jaiswal, Deepa; Marzano, Valeria; Neri, Sara; Ronci, Maurizio; Urbani, Andrea

2011-10-19

410

Nanomechanics of Yeast Surfaces Revealed by AFM  

NASA Astrophysics Data System (ADS)

Despite the large and well-documented characterization of the microbial cell wall in terms of chemical composition, the determination of the mechanical properties of surface molecules in relation to their function remains a key challenge in cell biology.The emergence of powerful tools allowing molecular manipulations has already revolutionized our understanding of the surface properties of fungal cells. At the frontier between nanophysics and molecular biology, atomic force microscopy (AFM), and more specifically single-molecule force spectroscopy (SMFS), has strongly contributed to our current knowledge of the cell wall organization and nanomechanical properties. However, due to the complexity of the technique, measurements on live cells are still at their infancy.In this chapter, we describe the cell wall composition and recapitulate the principles of AFM as well as the main current methodologies used to perform AFM measurements on live cells, including sample immobilization and tip functionalization.The current status of the progress in probing nanomechanics of the yeast surface is illustrated through three recent breakthrough studies. Determination of the cell wall nanostructure and elasticity is presented through two examples: the mechanical response of mannoproteins from brewing yeasts and elasticity measurements on lacking polysaccharide mutant strains. Additionally, an elegant study on force-induced unfolding and clustering of adhesion proteins located at the cell surface is also presented.

Dague, Etienne; Beaussart, Audrey; Alsteens, David

411

Speciation of chromium in chromium yeast.  

PubMed

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

2014-12-01

412

The architecture of yeast DNA polymerase ?  

PubMed Central

Summary DNA polymerase ? (Pol?) is specialized for the extension step of translesion DNA synthesis (TLS). Despite its central role in maintaining genome integrity, little is known about its overall architecture. Initially identified as a homodimer of the catalytic subunit Rev3 and the accessory subunit Rev7, yeast Pol? has recently been shown to form a stable four-subunit enzyme (Pol?-d) upon incorporation of Pol31 and Pol32, the accessory subunits of yeast Pol?. To understand the 3-D architecture and assembly of Pol? and Pol?-d we employed electron microscopy. We show here how the catalytic and accessory subunits of Pol? and Pol?-d are organized relative to each other. In particular, we show that Pol?-d has a bilobal architecture resembling the replicative polymerases, and that Pol32 lies in proximity to Rev7. Collectively, our study provides the first views of Pol? and Pol?-d, and a structural framework for understanding their roles in DNA damage bypass. PMID:24120860

Gomez-Llorente, Yacob; Malik, Radhika; Jain, Rinku; Choudhury, Jayati Roy; Johnson, Robert E.; Prakash, Louise; Prakash, Satya; Ubarretxena-Belandia, Iban; Aggarwal, Aneel K.

2013-01-01

413

Quantitative analysis of colony morphology in yeast  

PubMed Central

Microorganisms often form multicellular structures such as biofilms and structured colonies that can influence the organism’s virulence, drug resistance, and adherence to medical devices. Phenotypic classification of these structures has traditionally relied on qualitative scoring systems that limit detailed phenotypic comparisons between strains. Automated imaging and quantitative analysis have the potential to improve the speed and accuracy of experiments designed to study the genetic and molecular networks underlying different morphological traits. For this reason, we have developed a platform that uses automated image analysis and pattern recognition to quantify phenotypic signatures of yeast colonies. Our strategy enables quantitative analysis of individual colonies, measured at a single time point or over a series of time-lapse images, as well as the classification of distinct colony shapes based on image-derived features. Phenotypic changes in colony morphology can be expressed as changes in feature space trajectories over time, thereby enabling the visualization and quantitative analysis of morphological development. To facilitate data exploration, results are plotted dynamically through an interactive Yeast Image Analysis web application (YIMAA; http://yimaa.cs.tut.fi) that integrates the raw and processed images across all time points, allowing exploration of the image-based features and principal components associated with morphological development. PMID:24447135

Ruusuvuori, Pekka; Lin, Jake; Scott, Adrian C.; Tan, Zhihao; Sorsa, Saija; Kallio, Aleksi; Nykter, Matti; Yli-Harja, Olli; Shmulevich, Ilya; Dudley, Aimee M.

2014-01-01

414

Nucleotide degradation and ribose salvage in yeast  

PubMed Central

Nucleotide degradation is a universal metabolic capability. Here we combine metabolomics, genetics and biochemistry to characterize the yeast pathway. Nutrient starvation, via PKA, AMPK/SNF1, and TOR, triggers autophagic breakdown of ribosomes into nucleotides. A protein not previously associated with nucleotide degradation, Phm8, converts nucleotide monophosphates into nucleosides. Downstream steps, which involve the purine nucleoside phosphorylase, Pnp1, and pyrimidine nucleoside hydrolase, Urh1, funnel ribose into the nonoxidative pentose phosphate pathway. During carbon starvation, the ribose-derived carbon accumulates as sedoheptulose-7-phosphate, whose consumption by transaldolase is impaired due to depletion of transaldolase's other substrate, glyceraldehyde-3-phosphate. Oxidative stress increases glyceraldehyde-3-phosphate, resulting in rapid consumption of sedoheptulose-7-phosphate to make NADPH for antioxidant defense. Ablation of Phm8 or double deletion of Pnp1 and Urh1 prevent effective nucleotide salvage, resulting in metabolite depletion and impaired survival of starving yeast. Thus, ribose salvage provides means of surviving nutrient starvation and oxidative stress. PMID:23670538

Xu, Yi-Fan; Letisse, Fabien; Absalan, Farnaz; Lu, Wenyun; Kuznetsova, Ekaterina; Brown, Greg; Caudy, Amy A; Yakunin, Alexander F; Broach, James R; Rabinowitz, Joshua D

2013-01-01

415

[PSI+] Prion Variant Establishment in Yeast  

PubMed Central

Summary Differences in the clinical pathology of mammalian prion diseases reflect distinct heritable conformations of aggregated PrP proteins, called prion strains. Here, using the yeast [PSI+] prion, we examine the de novo establishment of prion strains (called variants in yeast). The [PSI+] prion protein, Sup35, is efficiently induced to take on numerous prion variant conformations following transient overexpression of Sup35 in the presence of another prion, e.g. [PIN+]. One hypothesis is that the first [PSI+] prion seed to arise in a cell causes propagation of only that seed’s variant, but that different variants could be initiated in different cells. However, we now show that even within a single cell, Sup35 retains the potential to fold into more than one variant type. When individual cells segregating different [PSI+] variants were followed in pedigrees, establishment of a single variant phenotype generally occurred in daughters, granddaughters or great granddaughters—but in 5% of the pedigrees cells continued to segregate multiple variants indefinitely. The data is consistent with the idea that many newly formed prions go through a maturation phase before they reach a single specific variant conformation. These findings may be relevant to mammalian PrP prion strain establishment and adaptation. PMID:22998111

Sharma, Jaya; Liebman, Susan W.

2012-01-01

416

Conservation of recombination hotspots in yeast  

PubMed Central

Meiotic recombination does not occur randomly along a chromosome, but instead tends to be concentrated in small regions, known as “recombination hotspots.” Recombination hotspots are thought to be short-lived in evolutionary time due to their self-destructive nature, as gene conversion favors recombination-suppressing alleles over recombination-promoting alleles during double-strand repair. Consistent with this expectation, hotspots in humans are highly dynamic, with little correspondence in location between humans and chimpanzees. Here, we identify recombination hotspots in two lineages of the yeast Saccharomyces paradoxus, and compare their locations to those found previously in Saccharomyces cerevisiae. Surprisingly, we find considerable overlap between the two species, despite the fact that they are at least 10 times more divergent than humans and chimpanzees. We attribute this unexpected result to the low frequency of sex and outcrossing in these yeasts, acting to reduce the population genetic effect of biased gene conversion. Traces from two other signatures of recombination, namely high mutagenicity and GC-biased gene conversion, are consistent with this interpretation. Thus, recombination hotspots are not inevitably short-lived, but rather their persistence through evolutionary time will be determined by the frequency of outcrossing events in the life cycle. PMID:20385822

Tsai, Isheng J.; Burt, Austin; Koufopanou, Vassiliki

2010-01-01

417

Alcohol-mediated haemolysis in yeast.  

PubMed

Although yeast are generally non-haemolytic, we have found that addition of alcohol vapour confers haemolytic properties on many strains of yeast and other fungi. We have called this phenomenon 'microbial alcohol-conferred haemolysis' (MACH). MACH is species- and strain-specific: whereas all six Candida tropicalis strains tested were haemolytic in the presence of ethanol, none among 10 C. glabrata strains tested exhibited this phenomenon. Among 27 C. albicans strains and 11 Saccharomyces cerevisiae strains tested, ethanol-mediated haemolysis was observed in 11 and 4 strains, respectively. Haemolysis is also dependent on the alcohol moiety: n-butanol and n-pentanol could also confer haemolysis, whereas methanol and 2-propanol did not. Haemolysis was found to be dependent on initial oxidation of the alcohol. Reduced haemolysis was observed in specific alcohol dehydrogenase mutants of both Aspergillus nidulans and S. cerevisiae. MACH was not observed during anaerobic growth, and was reduced in the presence of pararosaniline, an aldehyde scavenger. Results suggest that initial oxidation of the alcohol to the corresponding aldehyde is an essential step in the observed phenomenon. PMID:15565638

Shuster, Amir; Osherov, Nir; Rosenberg, Mel

2004-12-01

418

The impact of a dam on the helminth fauna and health of a neotropical fish species Salminus brasiliensis (Cuvier 1816) from the upper Paraná River, Brazil.  

PubMed

The aim of the present study was to detect changes in the structure of the helminth parasite infracommunities in Salminus brasiliensis (Cuvier 1816) from the floodplain of the upper Paraná River after construction of the Porto Primavera Hydroelectric Plant. A total of 126 fish in the period before the dam's construction and 56 specimens 10 years after this event were analysed. Three species of parasites were collected before the construction of the dam: Prosthenhystera obesa Diesing, 1850 (Digenea), Cladocystis intestinalis Vaz, 1932 (Digenea) and Monticellia coryphicephala Monticelli, 1892 (Cestoda), and one nematode species in the larval stage, whose identification was not possible. After dam construction, the following helminth parasites were found: C. intestinalis, M. coryphicephala, Octospiniferoides incognita, Contracaecum spp. larvae and Contracaecum sp. type 2 larvae Moravec, Kohn & Fernandes 1993. The diversity of helminth parasites measured by the Brillouin diversity index (HB) differed significantly between the pre- and post-dam periods (mean HB = 0.069 and HB = 0.2, respectively; P= 0.0479; Mann-Whitney U test). The parasite community of S. brasiliensis before the construction of the dam showed concentration of dominance (C) of P. obesa (C = 0.38), while there was no concentration of dominance of any species of parasite (C = 0.22) after the dam's construction. Before the Porto Primavera dam the relative condition factor of fish was 1.0; after the dam's construction it was 0.93 (P < 0.0001; Mann-Whitney U test). This study records the disappearance of the species P. obesa and suggests that there has been local extinction of this parasite. The results show that the anthropic influence on natural systems is interfering with the welfare and health of S. brasiliensis, reflected by its fauna of helminth parasites. PMID:22776324

Karling, L C; Isaac, A; Affonso, I P; Takemoto, R M; Pavanelli, G C

2013-06-01

419

Functional morphology of jaw trabeculation in the lesser electric ray Narcine brasiliensis, with comments on the evolution of structural support in the Batoidea.  

PubMed

The design of minimum-weight structures that retain their integrity under dynamic loading regimes has long challenged engineers. One solution to this problem found in both human and biological design is the optimization of weight and strength by hollowing a structure and replacing its inner core with supportive struts. In animals, this design is observed in sand dollar test, avian beak, and the cancellous bone of tetrapod limbs. Additionally, within the elasmobranch fishes, mineralized trabeculae (struts) have been reported in the jaws of durophagous myliobatid stingrays (Elasmobranchii: Batoidea), but were believed to be absent in basal members of the batoid clade. This study, however, presents an additional case of batoid trabeculation in the lesser electric ray, Narcine brasiliensis (Torpediniformes). The trabeculae in these species likely play different functional roles. Stingrays use their reinforced jaws to crush bivalves, yet N. brasiliensis feeds by ballistically protruding its jaws into the sediment to capture polychaetes. In N. brasiliensis, trabeculae are localized to areas likely to experience the highest load: the quadratomandibular jaw joints, hyomandibular-cranial joint, and the thinnest sections of the jaws immediately lateral to the symphyses. However, the supports perform different functions dependent on location. In regions where the jaws are loaded transversely (as in durophagous rays), "load leading" trabeculae distribute compressive forces from the cortex through the lumen of the jaws. In the parasymphyseal regions of the jaws, "truss" trabeculae form cross-braces perpendicular to the long axes of the jaws. At peak protrusion, the jaw arch is medially compressed and the jaw loaded axially such that these trabeculae are positioned to resist buckling associated with excavation forces. "Truss" trabeculae function to maintain the second moment of area in the thinnest regions of the jaws, illustrating a novel function for batoid trabeculation. Thus, this method of structural support appears to have arisen twice independently in batoids and performs strikingly different ecological functions associated with the distribution of extreme loading environments. PMID:15593310

Dean, Mason N; Huber, Daniel R; Nance, Holly A

2006-10-01

420

Yeast species associated with wine grapes in China.  

PubMed

Having more information on the yeast ecology of grapes is important for wine-makers to produce wine with high quality and typical attributes. China is a significant wine-consuming country and is becoming a serious wine-producer, but little has been reported about the yeast ecology of local ecosystems. This study provides the first step towards the exploitation of the yeast wealth in China's vine-growing regions. The aim of this study was to investigate the yeast population density and diversity on three grape varieties cultivated in four representative vine-growing regions of China. Yeast species diversity was evaluated by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequence analysis of the 5.8S internal transcribed spacer (ITS) ribosomal DNA (rDNA) region of cultivable yeasts. The grapes harbored yeast populations at 10(2)-10(6)CFU/mL, consisting mostly of non-Saccharomyces species. Seventeen different yeast species belonging to eight genera were detected on the grape samples tested, including Hanseniaspora uvarum, Cryptococcus flavescens, Pichia fermentans, Candida zemplinina, Cryptococcus carnescens, Candida inconpicua, Zygosaccharomyces fermentati, Issatchenkia terricola, Candida quercitrusa, Hanseniaspora guilliermondii, Candida bombi, Zygosaccharomyces bailii, Sporidiobolus pararoseus, Cryptococcus magnus, Metschnikowia pulcherrima, Issatchenkia orientalis and Pichia guilliermondii. H. uvarum and C. flavescens were the dominant species present on the grapes. For the first time Sporidiobolus pararoseus was discovered as an inhabitant of the grape ecosystem. The yeast community on grape berries was influenced by the grape chemical composition, vine-variety and vine-growing region. This study is the first to identify the yeast communities associated with grapes in China using molecular methods. The results enrich our knowledge of wine-related microorganisms, and can be used to promote the development of the local wine industry. PMID:20116124

Li, Shuang-Shi; Cheng, Chao; Li, Zheng; Chen, Jing-Yu; Yan, Bin; Han, Bei-Zhong; Reeves, Malcolm

2010-03-31

421

Carrier DNA For Yeast Transformation Preparation of high molecular weight single stranded carrier DNA for yeast transformations.  

E-print Network

with an equal volume of phenol:CHCl3. Centrifuge for 5 minutes to separate layers. 6. Precipitate DNA. Add 1Carrier DNA For Yeast Transformation Preparation of high molecular weight single stranded carrier DNA for yeast transformations. 1. Dissolve 100 mg DNA in 10 ml TE, pH 8 in a sterile 50 ml plastic

Aris, John P.

422

[Historic development of yeast genetics from the beginning to the first gene transformation in brewing yeast strains].  

PubMed

A more intensive use of the potential of brewing yeasts in the biotechnological process of br