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1

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

Microsoft Academic Search

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

Rosângela V Andrade; Hugo C Paes; André M Nicola; Maria José A de Carvalho; Ana Lúcia Fachin; Renato S Cardoso; Simoneide S Silva; Larissa Fernandes; Silvana P Silva; Eduardo A Donadi; Elza T Sakamoto-Hojo; Geraldo AS Passos; Célia MA Soares; Marcelo M Brígido; Maria Sueli S Felipe

2006-01-01

2

Cell Wall Composition of the Yeast and Mycelial Forms of Paracoccidioides brasiliensis  

PubMed Central

Isolation and chemical analyses of the cell walls of the yeast (Y form) and mycelial forms (M form) of Paracoccidioides brasiliensis and Blastomyces dermatitidis revealed that their chemical composition is similar and depends on the form. Lipids, chitin, glucans, and proteins are the main constituents of the cell walls of both forms of these fungi. There is no significant difference in the amount of lipids (5 to 10%) and glucans (36 to 47%) contained by the two forms. In both fungi, the Y form has a larger amount of chitin (37 to 48%) than the M form (7 to 18%), whereas the M form has a larger amount of proteins (24 to 41%) than the Y form (7 to 14%). Several properties of the glucan of P. brasiliensis were studied. Almost all of the glucan in the Y form was soluble in 1 n NaOH, was weakly positive in the periodic acid-Schiff reaction, was not hydrolyzed by snail digestive juice, and had ?-glycosidic linkage. Glucans of the M form were divided into alkali-soluble (60 to 65%) and alkali-insoluble (35 to 40%) types. The alkali-soluble glucan was similar to that of the Y form; the alkali-insoluble glucan was positive in the periodic acid-Schiff reaction and was hydrolyzed by snail digestive juice. PMID:5776517

Kanetsuna, Fuminori; Carbonell, Luis M.; Moreno, Ramon E.; Rodriguez, Joaquin

1969-01-01

3

Paracoccidioides brasiliensis, paracoccidioidomycosis, and antifungal antibiotics.  

PubMed

Paracoccidioides brasiliensis is the causative agent of paracoccidioidomycosis (PCM), a human systemic, chronic and progressive mycosis. Preferred antifungals are sulfamethoxazol-trimethoprim, itraconazole, amphotericin B. Treatment is lengthy, the drugs may have undesirable side effects, and some are costly. Occasional resistant strains have been reported. Therefore, the search for more selective and efficient antifungals to treat this and other mycoses continues. Ajoene, chemically derived from garlic, behaves as an antifungal agent against P. brasiliensis and other fungi. Its antiproliferative effects in P. brasiliensis are associated with a reduction of phosphatidyl choline, a concomitant increase in its precursor phosphatidyl ethanolamine, and a large increase in unsaturated fatty acids in the pathogenic yeast phase. The sterol biosynthetic pathway has been largely studied for the search of antifungals. Azoles and allilamines act on differents steps of this pathway. However, they may interfere with similar steps in the host. Hence, the search for drugs that may act on more specific steps is ongoing. One such step focuses on the sterol C-methylations catalyzed by the enzyme (S)-adenosyl-L-methionine: Delta(24) - sterol methyl transferase (SMT). SMT inhibitors such as azasterols and derivatives (AZA1, AZA2, AZA3) have proven highly effective as antiproliferative agents against protozoa and some fungi, among them, P. brasiliensis. Their chemical synthesis and structure, and their molecular electrostatic potential are discussed in order to understand their mechanism of action, and derive rationally designed improvements on these molecules, that would favour a higher efficacy and selectivity. PMID:16181141

Visbal, G; San-Blas, G; Murgich, J; Franco, H

2005-09-01

4

Influence of N-Glycosylation on the Morphogenesis and Growth of Paracoccidioides brasiliensis and on the Biological Activities of Yeast Proteins  

PubMed Central

The fungus Paracoccidioides brasiliensis is a human pathogen that causes paracoccidioidomycosis, the most prevalent systemic mycosis in Latin America. The cell wall of P. brasiliensis is a network of glycoproteins and polysaccharides, such as chitin, that perform several functions. N-linked glycans are involved in glycoprotein folding, intracellular transport, secretion, and protection from proteolytic degradation. Here, we report the effects of tunicamycin (TM)-mediated inhibition of N-linked glycosylation on P. brasiliensis yeast cells. The underglycosylated yeasts were smaller than their fully glycosylated counterparts and exhibited a drastic reduction of cell budding, reflecting impairment of growth and morphogenesis by TM treatment. The intracellular distribution in TM-treated yeasts of the P. brasiliensis glycoprotein paracoccin was investigated using highly specific antibodies. Paracoccin was observed to accumulate at intracellular locations, far from the yeast wall. Paracoccin derived from TM-treated yeasts retained the ability to bind to laminin despite their underglycosylation. As paracoccin has N-acetyl-?-d-glucosaminidase (NAGase) activity and induces the production of TNF-? and nitric oxide (NO) by macrophages, we compared these properties between glycosylated and underglycosylated yeast proteins. Paracoccin demonstrated lower NAGase activity when underglycosylated, although no difference was detected between the pH and temperature optimums of the two forms. Murine macrophages stimulated with underglycosylated yeast proteins produced significantly lower levels of TNF-? and NO. Taken together, the impaired growth and morphogenesis of tunicamycin-treated yeasts and the decreased biological activities of underglycosylated fungal components suggest that N-glycans play important roles in P. brasiliensis yeast biology. PMID:22216217

Dos Reis Almeida, Fausto Bruno; Carvalho, Fernanda Caroline; Mariano, Vânia Sammartino; Alegre, Ana Claudia Paiva; Silva, Roberto do Nascimento; Hanna, Ebert Seixas; Roque-Barreira, Maria Cristina

2011-01-01

5

Primers for Clinical Detection of Paracoccidioides brasiliensis  

PubMed Central

From a 0.72-kb fragment universally generated in Paracoccidioides brasiliensis strains, primers were designed and tested on genomic DNA of this and other pathogenic fungi. They were specific and highly sensitive for P. brasiliensis DNA. Positive results were obtained when these were tested in clinical samples. PMID:16081993

San-Blas, Gioconda; Niño-Vega, Gustavo; Barreto, Laura; Hebeler-Barbosa, Flavia; Bagagli, Eduardo; Olivero de Briceño, Rosa; Mendes, Rinaldo Poncio

2005-01-01

6

Identification, characterization and regulation studies of the aconitase of Paracoccidioides brasiliensis  

Microsoft Academic Search

A protein species preferentially expressed in yeast cells with a molecular mass of 80kDa and isoeletric point (pI) of 7.79 was isolated from the proteome of Paracoccidioides brasiliensis and characterized as an aconitase (ACO) (E.C. 4.2.1.3). ACO is an enzyme that catalyzes the isomerization of citrate to isocitrate in both the Krebs cycle and the glyoxylate cycle. We report the

Wesley de A. Brito; Tereza Cristina V. Rezende; Ana Flávia Parente; Carlos André O. Ricart; Marcelo V. de Sousa; Sônia N. Báo; Célia Maria de A. Soares

2011-01-01

7

Immunization with P10 peptide increases specific immunity and protects immunosuppressed BALB/c mice infected with virulent yeasts of Paracoccidioides brasiliensis.  

PubMed

Paracoccidioidomycosis is a systemic granulomatous disease caused by Paracoccidioides spp. A peptide from the major diagnostic antigen gp43, named P10, induces a T-CD4(+) helper-1 immune response in mice and protects against intratracheal challenge with virulent P. brasiliensis. Previously, we evaluated the efficacy of the P10 peptide alone or combined with antifungal drugs in mice immunosuppressed and infected with virulent isolate of P. brasiliensis. In the present work, our data suggest that P10 immunization leads to an effective cellular immune response associated with an enhanced T cell proliferative response. P10-stimulated splenocytes increased nitric oxide (NO) production and induced high levels of IFN-?, IL-1? and IL-12. Furthermore, significantly increased concentrations of pro-inflammatory cytokines were also observed in lung homogenates of immunized mice. P10 immunization was followed by minimal fibrosis in response to infection. Combined with antifungal drugs, P10 immunization most significantly improved survival of anergic infected mice. Administration of either itraconazole or sulfamethoxazole/trimethoprim together with P10 immunization resulted in 100 % survival up to 200 days post-infection, whereas untreated mice died within 80 days. Hence, our data show that P10 immunization promotes a strong specific immune response even in immunocompromised hosts and thus P10 treatment represents a powerful adjuvant therapy to chemotherapy. PMID:25135302

Muñoz, Julián E; Luft, Vinicius D; Amorim, Juliana; Magalhães, Adriana; Thomaz, Luciana; Nosanchuk, Joshua D; Travassos, Luiz R; Taborda, Carlos P

2014-10-01

8

A Paracoccidioides brasiliensis glycan shares serologic and functional properties with cryptococcal glucuronoxylomannan  

PubMed Central

The cell wall of the yeast form of the dimorphic fungus Paracoccidioides brasiliensis is enriched with ?1,3-glucans. In Cryptococcus neoformans, ?1,3-glucans interact with glucuronoxylomannan (GXM), a hetero polysaccharide that is essential for fungal virulence. In this study, we investigated the occurrence of P. brasiliensis glycans sharing properties with cryptococcal GXM. Protein database searches in P. brasiliensis revealed the presence of sequences homologous to those coding for enzymes involved in the synthesis of GXM and capsular architecture in C. neoformans. In addition, monoclonal antibodies (mAbs) raised to cryptococcal GXM bound to P. brasiliensis cells. Using protocols that were previously established for extraction and analysis of C. neoformans GXM, we recovered a P. brasiliensis glycan fraction composed of mannose and galactose, in addition to small amounts of glucose, xylose and rhamnose. In comparison with the C. neoformans GXM, the P. brasiliensis glycan fraction components had smaller molecular dimensions. The P. brasiliensis components, nevertheless, reacted with different GXM-binding mAbs. Extracellular vesicle fractions of P. brasiliensis also reacted with a GXM-binding mAb, suggesting that the polysaccharide-like molecule is exported to the extracellular space in secretory vesicles. An acapsular mutant of C. neoformans incorporated molecules from the P. brasiliensis extract onto the cell wall, resulting in the formation of surface networks that resembled the cryptococcal capsule. Coating the C. neoformans acapsular mutant with the P. brasiliensis glycan fraction resulted in protection against phagocytosis by murine macrophages. These results suggest that P. brasiliensis and C. neoformans share metabolic pathways required for the synthesis of similar polysaccharides and that P. brasiliensis yeast cell walls have molecules that mimic certain aspects of C. neoformans GXM. These findings are important because they provide additional evidence for the sharing of antigenically similar components across phylogenetically distant fungal species. Since GXM has been shown to be important for the pathogenesis of C. neoformans and to elicit protective antibodies, the finding of similar molecules in P. brasiliensis raises the possibility that these glycans play similar functions in paracoccidiomycosis. PMID:23010152

Albuquerque, Priscila C.; Cordero, Radames J.B.; Fonseca, Fernanda L.; da Silva, Roberta Peres; Ramos, Caroline L.; Miranda, Kildare R.; Casadevall, Arturo; Puccia, Rosana; Nosanchuk, Joshua D.; Nimrichter, Leonardo; Guimaraes, Allan J.; Rodrigues, Marcio L.

2015-01-01

9

Detection of Antibodies against Paracoccidioides brasiliensis Melanin in In Vitro and In Vivo Studies during Infection ?  

PubMed Central

Several cell wall constituents, including melanins or melanin-like compounds, have been implicated in the pathogenesis of a wide variety of microbial diseases caused by diverse species of pathogenic bacteria, fungi, and helminthes. Among these microorganisms, the dimorphic fungal pathogen Paracoccidioides brasiliensis produces melanin in its conidial and yeast forms. In the present study, melanin particles from P. brasiliensis were injected into BALB/c mice in order to produce monoclonal antibodies (MAbs). We identified five immunoglobulin G1 (IgG1) ?-chain and four IgM melanin-binding MAbs. The five IgG1 ?-chain isotypes are the first melanin-binding IgG MAbs ever reported. The nine MAbs labeled P. brasiliensis conidia and yeast cells both in vitro and in pulmonary tissues. The MAbs cross-reacted with melanin-like purified particles from other fungi and also with commercial melanins, such as synthetic and Sepia officinalis melanin. Melanization during paracoccidioidomycosis (PCM) was also further supported by the detection of IgG antibodies reactive to melanin from P. brasiliensis conidia and yeast in sera and bronchoalveolar lavage fluids from P. brasiliensis-infected mice, as well as in sera from human patients with PCM. Serum specimens from patients with other mycoses were also tested for melanin-binding antibodies by enzyme-linked immunosorbent assay, and cross-reactivities were detected for melanin particles from different fungal sources. These results suggest that melanin from P. brasiliensis is an immunologically active fungal structure that activates a strong IgG humoral response in humans and mice. PMID:21813659

Urán, Martha E.; Nosanchuk, Joshua D.; Restrepo, Angela; Hamilton, Andrew J.; Gómez, Beatriz L.; Cano, Luz E.

2011-01-01

10

Detection of antibodies against Paracoccidioides brasiliensis melanin in in vitro and in vivo studies during infection.  

PubMed

Several cell wall constituents, including melanins or melanin-like compounds, have been implicated in the pathogenesis of a wide variety of microbial diseases caused by diverse species of pathogenic bacteria, fungi, and helminthes. Among these microorganisms, the dimorphic fungal pathogen Paracoccidioides brasiliensis produces melanin in its conidial and yeast forms. In the present study, melanin particles from P. brasiliensis were injected into BALB/c mice in order to produce monoclonal antibodies (MAbs). We identified five immunoglobulin G1 (IgG1) ?-chain and four IgM melanin-binding MAbs. The five IgG1 ?-chain isotypes are the first melanin-binding IgG MAbs ever reported. The nine MAbs labeled P. brasiliensis conidia and yeast cells both in vitro and in pulmonary tissues. The MAbs cross-reacted with melanin-like purified particles from other fungi and also with commercial melanins, such as synthetic and Sepia officinalis melanin. Melanization during paracoccidioidomycosis (PCM) was also further supported by the detection of IgG antibodies reactive to melanin from P. brasiliensis conidia and yeast in sera and bronchoalveolar lavage fluids from P. brasiliensis-infected mice, as well as in sera from human patients with PCM. Serum specimens from patients with other mycoses were also tested for melanin-binding antibodies by enzyme-linked immunosorbent assay, and cross-reactivities were detected for melanin particles from different fungal sources. These results suggest that melanin from P. brasiliensis is an immunologically active fungal structure that activates a strong IgG humoral response in humans and mice. PMID:21813659

Urán, Martha E; Nosanchuk, Joshua D; Restrepo, Angela; Hamilton, Andrew J; Gómez, Beatriz L; Cano, Luz E

2011-10-01

11

Identification, characterization and regulation studies of the aconitase of Paracoccidioides brasiliensis.  

PubMed

A protein species preferentially expressed in yeast cells with a molecular mass of 80 kDa and isoeletric point (pI) of 7.79 was isolated from the proteome of Paracoccidioides brasiliensis and characterized as an aconitase (ACO) (E.C. 4.2.1.3). ACO is an enzyme that catalyzes the isomerization of citrate to isocitrate in both the Krebs cycle and the glyoxylate cycle. We report the cloning and characterization of the cDNA encoding the ACO of P. brasiliensis (PbACO). The cDNA showed a 2361 bp open reading frame (ORF) and encoded a predicted protein with 787 amino acids. Polyclonal antibodies against the purified recombinant PbACO was obtained in order to analyze the subcellular localization of the molecule in P. brasiliensis. The protein is present in the extracellular fluid, cell wall enriched fraction, mitochondria, cytosol and peroxisomes of yeast cells as demonstrated by western blot and immunocytochemistry analysis. The expression analysis of the Pbaco gene was performed by quantitative real-time RT-PCR and results demonstrated an increased expression in yeast cells compared to mycelia. Real-time RT-PCR assays was also used to evaluate the Pbaco expression when the fungus grows on media with acetate and ethanol as sole carbon sources and in different iron levels. The results demonstrated that Pbaco transcript is over expressed in acetate and ethanol as sole carbon sources and in high-iron conditions. PMID:21802049

Brito, Wesley de A; Rezende, Tereza Cristina V; Parente, Ana Flávia; Ricart, Carlos André O; Sousa, Marcelo V de; Báo, Sônia N; Soares, Célia Maria de A

2011-08-01

12

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.; Bailão, Alexandre M.; Borges, Clayton L.; Parente, Juliana A.; Magalhães, Adriana D.; Ricart, Carlos A. O.; Soares, Célia M. A.

2011-01-01

13

Cryptic species of Paracoccidioides brasiliensis: impact on paracoccidioidomycosis immunodiagnosis  

PubMed Central

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

2013-01-01

14

Diversity in Paracoccidioides brasiliensis . The Pb GP43 gene as a genetic marker  

Microsoft Academic Search

Paracoccidioides brasiliensis is a temperature-dependent dimorphic fungus and the agent of paracoccidioidomycosis (PCM), which is prevalent in rural workers\\u000a of Latin American countries. Until a decade ago, most of the studies involving P. brasiliensis used clinical isolates, since environmental samples from soil are difficult to obtain. More recently, P. brasiliensis has been isolated from infected wild and domestic animals, especially

Rosana Puccia; Juan G. McEwen; Patrícia S. Cisalpino

2008-01-01

15

Lipidomic Analysis of Extracellular Vesicles from the Pathogenic Phase of Paracoccidioides brasiliensis  

PubMed Central

Background Fungal extracellular vesicles are able to cross the cell wall and transport molecules that help in nutrient acquisition, cell defense, and modulation of the host defense machinery. Methodology/Principal Findings Here we present a detailed lipidomic analysis of extracellular vesicles released by Paracoccidioides brasiliensis at the yeast pathogenic phase. We compared data of two representative isolates, Pb3 and Pb18, which have distinct virulence profiles and phylogenetic background. Vesicle lipids were fractionated into different classes and analyzed by either electrospray ionization- or gas chromatography-mass spectrometry. We found two species of monohexosylceramide and 33 phospholipid species, including phosphatidylcholine, phosphatidylethanolamine, phosphatidic acid, phosphatidylserine, phosphatidylinositol, and phosphatidylglycerol. Among the phospholipid-bound fatty acids in extracellular vesicles, C181 predominated in Pb3, whereas C18:2 prevailed in Pb18. The prevalent sterol in Pb3 and Pb18 vesicles was brassicasterol, followed by ergosterol and lanosterol. Inter-isolate differences in sterol composition were observed, and also between extracellular vesicles and whole cells. Conclusions/Significance The extensive lipidomic analysis of extracellular vesicles from two P. brasiliensis isolates will help to understand the composition of these fungal components/organelles and will hopefully be useful to study their biogenesis and role in host-pathogen interactions. PMID:22745761

Longo, Larissa V. G.; Ganiko, Luciane; Lopes, Felipe G.; Matsuo, Alisson L.; Almeida, Igor C.; Puccia, Rosana

2012-01-01

16

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

17

Epithelial cells treated with genistein inhibit adhesion and endocytosis of Paracoccidioides brasiliensis  

Microsoft Academic Search

Paracoccidioidomycosis is caused by Paracoccidioides brasiliensis, which although not formally considered an intracellular pathogen, can be internalized by epithelial cells in vitro and in\\u000a vivo. The mechanisms used by P. brasiliensis to adhere to and invade non-professional phagocytes have not been identified. The signal-transduction networks, involving\\u000a protein tyrosine kinase (PTK) and protein phosphatase activities, can modulate crucial events during fungal

J. L. Monteiro da Silva; P. F. Andreotti; G. Benard; C. P. Soares; E. T. Miranda; M. J. S. Mendes-Giannini

2007-01-01

18

Analysis of the Secretomes of Paracoccidioides Mycelia and Yeast Cells  

PubMed Central

Paracoccidioides, a complex of several phylogenetic species, is the causative agent of paracoccidioidomycosis. The ability of pathogenic fungi to develop a multifaceted response to the wide variety of stressors found in the host environment is important for virulence and pathogenesis. Extracellular proteins represent key mediators of the host-parasite interaction. To analyze the expression profile of the proteins secreted by Paracoccidioides, Pb01 mycelia and yeast cells, we used a proteomics approach combining two-dimensional electrophoresis with matrix-assisted laser desorption ionization quadrupole time-of-flight mass spectrometry (MALDI-Q-TOF MS/MS). From three biological replicates, 356 and 388 spots were detected, in mycelium and yeast cell secretomes, respectively. In this study, 160 non-redundant proteins/isoforms were indentified, including 30 and 24 proteins preferentially secreted in mycelia and yeast cells, respectively. In silico analyses revealed that 65% of the identified proteins/isoforms were secreted primarily via non-conventional pathways. We also investigated the influence of protein export inhibition in the phagocytosis of Paracoccidioides by macrophages. The addition of Brefeldin A to the culture medium significantly decreased the production of secreted proteins by both Paracoccidioides and internalized yeast cells by macrophages. In contrast, the addition of concentrated culture supernatant to the co-cultivation significantly increased the number of internalized yeast cells by macrophages. Importantly, the proteins detected in the fungal secretome were also identified within macrophages. These results indicate that Paracoccidioides extracellular proteins are important for the fungal interaction with the host. PMID:23272246

Weber, Simone Schneider; Parente, Ana Flávia Alves; Borges, Clayton Luiz; Parente, Juliana Alves; Bailão, Alexandre Melo; de Almeida Soares, Célia Maria

2012-01-01

19

Expression of Paracoccidioides brasiliensis AMY1 in a Histoplasma capsulatum amy1 Mutant, Relates an ?-(1,4)-Amylase to Cell Wall ?-(1,3)-Glucan Synthesis  

PubMed Central

In the cell walls of the pathogenic yeast phases of Paracoccidioides brasiliensis, Blastomyces dermatitidis and Histoplasma capsulatum, the outer ?-(1,3)-glucan layer behaves as a virulence factor. In H. capsulatum, an ?-(1,4)-amylase gene (AMY1) is essential for the synthesis of this polysaccharide, hence related to virulence. An orthologous gene to H. capsulatum AMY1 was identified in P. brasiliensis and also labeled AMY1. P. brasiliensis AMY1 transcriptional levels were increased during the yeast phase, which correlates with the presence of ?-(1,3)-glucan as the major yeast cell wall polysaccharide. Complementation of a H. capsulatum amy1 mutant strain with P. brasiliensis AMY1, suggests that P. brasiliensis Amy1p may play a role in the synthesis of cell wall ?-(1,3)-glucan. To study some biochemical properties of P. brasiliensis Amy1p, the enzyme was overexpressed, purified and studied its activity profile with starch and amylopeptin. It showed a relatively higher hydrolyzing activity on amylopeptin than starch, producing oligosaccharides from 4 to 5 glucose residues. Our findings show that P. brasiliensis Amy1p produces maltooligosaccharides which may act as a primer molecule for the fungal cell wall ?-(1,3)-glucan biosynthesis by Ags1p. PMID:23185578

Camacho, Emma; Sepulveda, Victoria E.; Goldman, William E.; San-Blas, Gioconda; Niño-Vega, Gustavo A.

2012-01-01

20

Low Concentrations of Hydrogen Peroxide or Nitrite Induced of Paracoccidioides brasiliensis Cell Proliferation in a Ras-Dependent Manner  

PubMed Central

Paracoccidioides brasiliensis, a causative agent of paracoccidioidomycosis (PCM), should be able to adapt to dramatic environmental changes inside the infected host after inhalation of air-borne conidia and transition to pathogenic yeasts. Proteins with antioxidant functions may protect fungal cells against reactive oxygen (ROS) and nitrogen (RNS) species generated by phagocytic cells, thus acting as potential virulence factors. Ras GTPases are involved in stress responses, cell morphology, and differentiation in a range of organisms. Ras, in its activated form, interacts with effector proteins and can initiate a kinase cascade. In lower eukaryotes, Byr2 kinase represents a Ras target. The present study investigated the role of Ras in P. brasiliensis after in vitro stimulus with ROS or RNS. We have demonstrated that low concentrations of H2O2 (0.1 mM) or NO2 (0.1–0.25 µM) stimulated P. brasiliensis yeast cell proliferation and that was not observed when yeast cells were pre-incubated with farnesyltransferase inhibitor. We constructed an expression plasmid containing the Byr2 Ras-binding domain (RBD) fused with GST (RBD-Byr2-GST) to detect the Ras active form. After stimulation with low concentrations of H2O2 or NO2, the Ras active form was observed in fungal extracts. Besides, NO2 induced a rapid increase in S-nitrosylated Ras levels. This alternative posttranslational modification of Ras, probably in residue Cys123, would lead to an exchange of GDP for GTP and consequent GTPase activation in P. brasiliensis. In conclusion, low concentrations of H2O2 or NO2 stimulated P. brasiliensis proliferation through Ras activation. PMID:23922749

Haniu, Ana Eliza Coronel Janu; Maricato, Juliana Terzi; Mathias, Pedro Paulo Moraes; Castilho, Daniele Gonçalves; Miguel, Rodrigo Bernardi; Monteiro, Hugo Pequeno; Puccia, Rosana; Batista, Wagner Luiz

2013-01-01

21

Inhibition of Paracoccidioides brasiliensis by ajoene is associated with blockade of phosphatidylcholine biosynthesis.  

PubMed

In Paracoccidioides brasiliensis, a dimorphic fungus pathogenic for humans, no significant differences were observed in the phospholipid species of both morphological phases. The species observed were phosphatidylcholine (PC, 30-40%), phosphatidylethanolamine (PE, 27-28%), phosphatidylserine (16-19%), phosphatidylinositol (13-17%) and sphingomyelin (3-5%). The main fatty acids found in the yeast (Y) phase were palmitate (56%), linoleate (18%) and oleate (15%), while linoleate predominated (61%) in the mycelial (M) phase, followed by palmitate (27%) and oleate (7%). In the Y phase the main free sterol was ergosta-5,22-dien-3 beta-ol (82%) plus some lanosterol (12%) and ergosterol (6%), while in the M phase, the latter predominated (88%), followed by low levels of ergosta-5,22-dien-3 beta-ol (12%). Ajoene [(E,Z)-4,5,9-trithiadodeca-1,6,11-triene 9-oxide], a platelet aggregation inhibitor derived from garlic, induced alterations in phospholipid and fatty acid proportions such that PC was reduced to about 18% in both phases and PE increased to 38% (Y phase) or 44% (M phase), suggesting inhibition of PC synthesis. Ajoene also reduced saturated fatty acids (16:0 and 18:0) from 67 to 35% in the Y phase, with a corresponding increase in the unsaturated components. This effect was not seen in the M phase. PMID:9168609

San-Blas, G; Urbina, J A; Marchán, E; Contreras, L M; Sorais, F; San-Blas, F

1997-05-01

22

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; Bailão, 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

23

Paracoccidioides brasiliensis 87-Kilodalton Antigen, a Heat Shock Protein Useful in Diagnosis: Characterization, Purification, and Detection in Biopsy Material via Immunohistochemistry  

PubMed Central

The 87-kDa antigen derived from the fungal pathogen Paracoccidioides brasiliensis can be detected in the sera of infected patients, and its levels have been shown to correlate well with response to treatment and with clinical cure. Despite its potential importance, the antigen has been poorly characterized. The 87-kDa antigen was purified to homogeneity via preparative gel electrophoresis; N-terminal amino acid sequencing revealed substantial homology with heat shock proteins (hsps) from a variety of organisms. A monoclonal antibody (MAb) raised against a Histoplasma capsulatum 80-kDa hsp showed cross-reactivity to the purified 87-kDa antigen via Western blotting, and the 87-kDa-specific MAb P1B demonstrated that the antigen was expressed at higher levels in yeast than in mycelia by the same technique. Enzyme-linked immunosorbent assay and immunofluorescence reactivity using P1B confirmed increased expression of the 87-kDa antigen during the temperature-induced transformation of mycelia to yeast. Yeast-to-mycelium transformation was accompanied by a fall in expression, although the 87-kDa antigen was clearly constitutively expressed in both phases. Immunochemical staining of tissues from patients with MAb P1B who were infected with P. brasiliensis confirmed in vivo expression of the 87-kDa antigen by yeasts, and identification of this antigen via this method appears to be a useful adjunct to other methods used to diagnose paracoccidioidomycosis. PMID:11825942

Díez, Soraya; Gómez, Beatriz L.; Restrepo, Angela; Hay, Rod J.; Hamilton, Andrew J.

2002-01-01

24

Influence of different media, incubation times, and temperatures for determining the MICs of seven antifungal agents against Paracoccidioides brasiliensis by microdilution.  

PubMed

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; Cisalpino, P S

2013-02-01

25

Characterization of gp70 and Anti-gp70 Monoclonal Antibodies in Paracoccidioides brasiliensis Pathogenesis  

PubMed Central

Paracoccidioidomycosis (PCM) is a systemic granulomatous mycosis whose agent is Paracoccidioides brasiliensis. In the culture supernatant, the fungus expresses glycoproteins of from 13 to 148 kDa. A cell surface glycoprotein of 43 kDa is the major antigenic component of P. brasiliensis. Another expressed glycoprotein, gp70, is recognized by 96% of sera from PCM patients and is able to induce lymphoproliferation. Since, little is known about this glycoprotein, we produced monoclonal antibodies (MAbs) against gp70 to isolate the molecule from total fungus extracts and to investigate its possible role in the pathogenesis of PCM. Using these MAbs, it was observed by confocal microscopy that gp70 is located mainly in the intracellular compartment of the fungus, although it was also detected in the culture supernatant. Based on observations showing that gp43 has a down-regulatory effect on mouse peritoneal macrophages, we tested the effects of gp70 on their phagocytic ability. Purified gp70 was able to inhibit the activity of macrophages through the mannose receptors and also through the Fc receptors; the latter effect was not observed with gp43. gp70 inhibits NO and H2O2 liberation by peritoneal macrophages in vitro, as does gp43. Results obtained with gp43 led us to hypothesize that gp70 could act as an escape mechanism for fungal establishment in primary infections. To corroborate this hypothesis, we analyzed the effect of passive immunization of mice during infection with P. brasiliensis using anti-gp70 MAbs. This treatment almost completely abolished granuloma formation in the lungs, suggesting that the protein facilitates fungal establishment and progression of lesions in primary infection. PMID:14573675

de Mattos Grosso, Daniela; de Almeida, Sandro Rogério; Mariano, Mario; Lopes, Jose Daniel

2003-01-01

26

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; Bailão, Alexandre M; Borges, Clayton L; Faria, Fabricia P; Felipe, Maria SS; Silva, Mirelle G; Martins, Wellington S; Fiúza, Rogério B; Pereira, Maristela; Soares, Célia MA

2007-01-01

27

Histological and ultrastructural study of the inflammation evoked by Paracoccidioides brasiliensis antigen in previously immunized mice.  

PubMed

Bentonite particles uncoated and coated with soluble antigen of Paracoccidioides brasiliensis (Pb) were intravenously injected into mice with and without previous immunization with Pb antigen. The inflammatory reaction around the bentonite emboli in small lung vessels was quantitated and morphologically studied by light and electron (EM) microscopy, 2 to 8 days after challenge. In control nonimmunized animals, coated and uncoated bentonite particles caused mild and nonspecific inflammation made up by macrophages. By EM, they formed loosely aggregated clusters with cytoplasm containing few organelles and borders without interdigitation. In immunized mice injected with coated bentonite particles, the inflammatory area was significantly greater than that in nonimmunized animals in all periods of study with maximum difference at day 2. The inflammatory process at days 2 and 4 was characterized as mature granulomata, composed of macrophages with great number of organelles in the cytoplasm, large euchromatic nuclei and prominent nucleoli. Altogether these findings indicated a lesion with high metabolic activity, compatible with a granulomatous hypersensitivity reaction. At days 6 and 8, there was a change from mature to epithelioid granulomata, well demonstrated by EM which showed macrophages with characteristically interdigitated cytoplasmic borders. The results strengthen the importance of cellular immunity in the genesis of epithelioid granuloma in paracoccidioidomycosis and reinforce the usefulness of the present model in studies of the inflammatory cellular sequency and events in this mycosis. PMID:2739693

Defaveri, J; Martin, L C; Franco, M

1989-01-01

28

The Homeostasis of Iron, Copper, and Zinc in Paracoccidioides Brasiliensis, Cryptococcus Neoformans Var. Grubii, and Cryptococcus Gattii: A Comparative Analysis  

PubMed Central

Iron, copper, and zinc are essential for all living organisms. Moreover, the homeostasis of these metals is vital to microorganisms during pathogenic interactions with a host. Most pathogens have developed specific mechanisms for the uptake of micronutrients from their hosts in order to counteract the low availability of essential ions in infected tissues. We report here an analysis of genes potentially involved in iron, copper, and zinc uptake and homeostasis in the fungal pathogens Paracoccidioides brasiliensis, Cryptococcus neoformans var. grubii, and Cryptococcus gattii. Although prior studies have identified certain aspects of metal regulation in Cryptococcus species, little is known regarding the regulation of these elements in P. brasiliensis. We also present amino acid sequences analyses of deduced proteins in order to examine possible conserved domains. The genomic data reveals, for the first time, genes associated to iron, copper, and zinc assimilation and homeostasis in P. brasiliensis. Furthermore, analyses of the three fungal species identified homologs to genes associated with high-affinity uptake systems, vacuolar and mitochondrial iron storage, copper uptake and reduction, and zinc assimilation. However, homologs to genes involved in siderophore production were only found in P. brasiliensis. Interestingly, in silico analysis of the genomes of P. brasiliensis Pb01, Pb03, and Pb18 revealed significant differences in the presence and/or number of genes involved in metal homeostasis, such as in genes related to iron reduction and oxidation. The broad analyses of the genomes of P. brasiliensis, C. neoformans var. grubii, and C. gattii for genes involved in metal homeostasis provide important groundwork for numerous interesting future areas of investigation that are required in order to validate and explore the function of the identified genes and gene pathways. PMID:21833306

Silva, Mirelle Garcia; Schrank, Augusto; Bailão, Elisa Flávia L.C.; Bailão, Alexandre Melo; Borges, Clayton Luiz; Staats, Charley Christian; Parente, Juliana Alves; Pereira, Maristela; Salem-Izacc, Silvia Maria; Mendes-Giannini, Maria José Soares; Oliveira, Rosely Maria Zancopé; Silva, Lívia Kmetzsch Rosa e; Nosanchuk, Joshua D.; Vainstein, Marilene Henning; de Almeida Soares, Célia Maria

2011-01-01

29

?-(1,4)-Amylase, but not ?- and ?-(1,3)-glucanases, may be responsible for the impaired growth and morphogenesis of Paracoccidioides brasiliensis induced by N-glycosylation inhibition  

PubMed Central

The cell wall of Paracoccidioides brasiliensis, which consists of a network of polysaccharides and glycoproteins, is essential for fungal pathogenesis. We have previously reported that N-glycosylation of proteins such as N-acetyl-?-d-glucosaminidase is required for the growth and morphogenesis of P. brasiliensis. In the present study, we investigated the influence of tunycamicin (TM)-mediated inhibition of N-linked glycosylation on ?- and ?-(1,3)-glucanases and on ?-(1,4)-amylase in P. brasiliensis yeast and mycelium cells. The addition of 15 µg/ml TM to the fungal cultures did not interfere with either ?- or ?-(1,3)-glucanase production and secretion. Moreover, incubation with TM did not alter ?- and ?-(1,3)-glucanase activity in yeast and mycelium cell extracts. In contrast, ?-(1,4)-amylase activity was significantly reduced in underglycosylated yeast and mycelium extracts after exposure to TM. In spite of its importance for fungal growth and morphogenesis, N-glycosylation was not required for glucanase activities. This is surprising because these activities are directed to wall components that are crucial for fungal morphogenesis. On the other hand, N-glycans were essential for ?-(1,4)-amylase activity involved in the production of malto-oligosaccharides that act as primer molecules for the biosynthesis of ?-(1,3)-glucan. Our results suggest that reduced fungal ?-(1,4)-amylase activity affects cell wall composition and may account for the impaired growth of underglycosylated yeast and mycelium cells. © 2013 The Authors. Yeast published by John Wiley & Sons Ltd. PMID:24155051

Dos Reis Almeida, Fausto Bruno; Pigosso, Laurine Lacerda; de Lima Damásio, André Ricardo; Monteiro, Valdirene Neves; de Almeida Soares, Célia Maria; Silva, Roberto Nascimento; Roque-Barreira, Maria Cristina

2014-01-01

30

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

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

2014-01-01

31

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

32

Biochemical Characterization of Paracoccidioides brasiliensis ?-1,3-Glucanase Agn1p, and Its Functionality by Heterologous Expression in Schizosaccharomyces pombe  

PubMed Central

?-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

33

The PbMDJ1 Gene Belongs to a Conserved MDJ1/LON Locus in Thermodimorphic Pathogenic Fungi and Encodes a Heat Shock Protein That Localizes to both the Mitochondria and Cell Wall of Paracoccidioides brasiliensis  

PubMed Central

J-domain (DnaJ) proteins, of the Hsp40 family, are essential cofactors of their cognate Hsp70 chaperones, besides acting as independent chaperones. In the present study, we have demonstrated the presence of Mdj1, a mitochondrial DnaJ member, not only in the mitochondria, where it is apparently sorted, but also in the cell wall of Paracoccidioides brasiliensis, a thermodimorphic pathogenic fungus. The molecule (PbMdj1) was localized to fungal yeast cells using both confocal and electron microscopy and also flow cytometry. The anti-recombinant PbMdj1 antibodies used in the reactions specifically recognized a single 55-kDa mitochondrial and cell wall (alkaline ?-mercaptoethanol extract) component, compatible with the predicted size of the protein devoid of its matrix peptide-targeting signal. Labeling was abundant throughout the cell wall and especially in the budding regions; however, anti-PbMdj1 did not affect fungal growth in the concentrations tested in vitro, possibly due to the poor access of the antibodies to their target in growing cells. Labeled mitochondria stood preferentially close to the plasma membrane, and gold particles were detected in the thin space between them, toward the cell surface. We show that Mdj1 and the mitochondrial proteinase Lon homologues are heat shock proteins in P. brasiliensis and that their gene organizations are conserved among thermodimorphic fungi and Aspergillus, where the genes are adjacent and have a common 5? region. This is the first time a DnaJ member has been observed on the cell surface, where its function is speculative. PMID:16467478

Batista, Wagner L.; Matsuo, Alisson L.; Ganiko, Luciane; Barros, Tânia F.; Veiga, Thiago R.; Freymüller, Edna; Puccia, Rosana

2006-01-01

34

Microplate alamarBlue Assay for Paracoccidioides Susceptibility Testing  

PubMed Central

CLSI method M27-A3 is not available for use with dimorphic fungi, such as those of the Paracoccidioides genus. In this study, we developed a microdilution method and added the alamarBlue reagent to test the responses of Paracoccidioides brasiliensis and Paracoccidioides lutzii against amphotericin B and itraconazole antifungals. The test proved to be sensitive, practical, and inexpensive and can be used to monitor the activity of low-growth microorganisms and their response to various drugs. PMID:23345296

de Paula e Silva, A. C. A.; Oliveira, H. C.; Silva, J. F.; Sangalli-Leite, F.; Scorzoni, L.; Fusco-Almeida, A. M.

2013-01-01

35

Screening non-coding RNAs in transcriptomes from neglected species using PORTRAIT: case study of the pathogenic fungus Paracoccidioides brasiliensis  

PubMed Central

Background Transcriptome sequences provide a complement to structural genomic information and provide snapshots of an organism's transcriptional profile. Such sequences also represent an alternative method for characterizing neglected species that are not expected to undergo whole-genome sequencing. One difficulty for transcriptome sequencing of these organisms is the low quality of reads and incomplete coverage of transcripts, both of which compromise further bioinformatics analyses. Another complicating factor is the lack of known protein homologs, which frustrates searches against established protein databases. This lack of homologs may be caused by divergence from well-characterized and over-represented model organisms. Another explanation is that non-coding RNAs (ncRNAs) may be caught during sequencing. NcRNAs are RNA sequences that, unlike messenger RNAs, do not code for protein products and instead perform unique functions by folding into higher order structural conformations. There is ncRNA screening software available that is specific for transcriptome sequences, but their analyses are optimized for those transcriptomes that are well represented in protein databases, and also assume that input ESTs are full-length and high quality. Results We propose an algorithm called PORTRAIT, which is suitable for ncRNA analysis of transcriptomes from poorly characterized species. Sequences are translated by software that is resistant to sequencing errors, and the predicted putative proteins, along with their source transcripts, are evaluated for coding potential by a support vector machine (SVM). Either of two SVM models may be employed: if a putative protein is found, a protein-dependent SVM model is used; if it is not found, a protein-independent SVM model is used instead. Only ab initio features are extracted, so that no homology information is needed. We illustrate the use of PORTRAIT by predicting ncRNAs from the transcriptome of the pathogenic fungus Paracoccidoides brasiliensis and five other related fungi. Conclusion PORTRAIT can be integrated into pipelines, and provides a low computational cost solution for ncRNA detection in transcriptome sequencing projects. PMID:19653905

Arrial, Roberto T; Togawa, Roberto C; Brigido, Marcelo de M

2009-01-01

36

Characterization of Cell Wall Lipids from the Pathogenic Phase of Paracoccidioides brasiliensis Cultivated in the Presence or Absence of Human Plasma  

PubMed Central

Background The fungal cell wall is a complex and dynamic outer structure. In pathogenic fungi its components interact with the host, determining the infection fate. The present work aimed to characterize cell wall lipids from P. brasiliensis grown in the presence and absence of human plasma. We compared the results from isolates Pb3 and Pb18, which represent different phylogenetic species that evoke distinct patterns of experimental paracoccidioidomycosis. Methodology/Principal Findings We comparatively characterized cell wall phospholipids, fatty acids, sterols, and neutral glycolipids by using both electrospray ionization- and gas chromatography-mass spectrometry analyses of lipids extracted with organic solvents followed by fractionation in silica-gel-60. We detected 49 phospholipid species in Pb3 and 38 in Pb18, including phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylglycerol, phosphatidylinositol, and phosphatidic acid. In both Pb3 and Pb18, PC and PE had the most numerous species. Among the fatty acids, C18?1 and C18?2 were the most abundant species in both isolates, although C18?2 was more abundant in Pb18. There was a different effect of plasma supplementation on fatty acids depending on the fungal isolate. The prevalent glycolipid species was Hex-C18?0-OH/d19?2-Cer, although other four minor species were also detected. The most abundant sterol in all samples was brassicasterol. Distinct profiles of cell wall and total yeast sterols suggested that the preparations were enriched for cell wall components. The presence of plasma in the culture medium specially increased cell wall brassicasterol abundance and also other lipids. Conclusions/Significance We here report an original comparative lipidomic analysis of P. brasiliensis cell wall. Our results open doors to understanding the role of cell wall lipids in fungal biology, and interaction with anti-fungal drugs and the host. PMID:23691038

Gazos-Lopes, Felipe; Vallejo, Milene C.; Matsuo, Alisson L.; Almeida, Igor C.; Puccia, Rosana

2013-01-01

37

NUTRITIONAL STUDIES ON THE YEAST PHASE OF BLASTOMYCES DERMATITIDIS AND B. BRASILIENSIS1  

PubMed Central

Gilardi, Gerald L. (University of Maryland, College Park) and Norman C. Laffer. Nutritional studies on the yeast phase of Blastomyces dermatitidis and B. brasiliensis. J. Bacteriol. 83:219–227. 1962.—Nutritional characteristics of the yeast phase of 22 cultures of the genus Blastomyces (9 of B. brasiliensis and 13 of B. dermatitidis) were examined to see if differences in nutritional behavior occurred which could serve as an aid in a more definitive classification. The studies included vitamin and amino acid requirements, carbon and nitrogen assimilation tests, and comparison of growth obtained with quiescent, agar slant, and shake cultures. Both species synthesized their own vitamins, utilized the same 21 carbon and 25 nitrogen substrates as the sole source of the respective element, and produced their most luxuriant growth in shake cultures in the presence of either ammonium salts or organic nitrogen. Sulfur-containing compounds, reducing agents, and Tween 80 were observed to retard or inhibit growth. Inhibition of yeast phase maintenance, and the conversion to the mold phase at 35 C, occurred in the presence of tyrosine. No difference was detected between the two species; variation occurred only at the culture level. On the basis of the similarity of nutritional characteristics, there appears to be no justification to separate the two species into separate genera, as proposed by some authors. PMID:13898529

Gilardi, Gerald L.; Laffer, Norman C.

1962-01-01

38

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

39

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

40

In Silico Prediction of Peptides Binding to Multiple HLA-DR Molecules Accurately Identifies Immunodominant Epitopes from gp43 of Paracoccidioides brasiliensis Frequently Recognized in Primary Peripheral Blood Mononuclear Cell Responses from Sensitized Individuals  

PubMed Central

One of the major drawbacks limiting the use of synthetic peptide vaccines in genetically distinct populations is the fact that different epitopes are recognized by T cells from individuals displaying distinct major histocompatibility complex molecules. Immunization of mice with peptide (181-195) from the immunodominant 43 kDa glycoprotein of Paracoccidioides brasiliensis (gp43), the causative agent of Paracoccidioidomycosis (PCM), conferred protection against infectious challenge by the fungus. To identify immunodominant and potentially protective human T-cell epitopes in gp43, we used the TEPITOPE algorithm to select peptide sequences that would most likely bind multiple HLA-DR molecules and tested their recognition by T cells from sensitized individuals. The 5 most promiscuous peptides were selected from the gp43 sequence and the actual promiscuity of HLA binding was assessed by direct binding assays to 9 prevalent HLA-DR molecules. Synthetic peptides were tested in proliferation assays with peripheral blood mononuclear cells (PBMC) from PCM patients after chemotherapy and healthy controls. PBMC from 14 of 19 patients recognized at least one of the promiscuous peptides, whereas none of the healthy controls recognized the gp43 promiscuous peptides. Peptide gp43(180-194) was recognized by 53% of patients, whereas the other promiscuous gp43 peptides were recognized by 32% to 47% of patients. The frequency of peptide binding and peptide recognition correlated with the promiscuity of HLA-DR binding, as determined by TEPITOPE analysis. In silico prediction of promiscuous epitopes led to the identification of naturally immunodominant epitopes recognized by PBMC from a significant proportion of a genetically heterogeneous patient population exposed to P. brasiliensis. The combination of several such epitopes may increase the frequency of positive responses and allow the immunization of genetically distinct populations. PMID:15208742

Iwai, Leo Kei; Yoshida, Márcia; Sidney, John; Shikanai-Yasuda, Maria Aparecida; Goldberg, Anna Carla; Juliano, Maria Aparecida; Hammer, Jurgen; Juliano, Luiz; Sette, Alessandro; Kalil, Jorge; Travassos, Luiz Rodolpho; Cunha-Neto, Edecio

2003-01-01

41

Genus Paracoccidioides: Species Recognition and Biogeographic Aspects  

PubMed Central

Background Paracoccidioidomycosis is a systemic mycosis caused by Paracoccidioides brasiliensis (species S1, PS2, PS3), and Paracoccidioides lutzii. This work aimed to differentiate species within the genus Paracoccidioides, without applying multilocus sequencing, as well as to obtain knowledge of the possible speciation processes. Methodology/Principal Findings Single nucleotide polymorphism analysis on GP43, ARF and PRP8 intein genes successfully distinguished isolates into four different species. Morphological evaluation indicated that elongated conidia were observed exclusively in P. lutzii isolates, while all other species (S1, PS2 and PS3) were indistinguishable. To evaluate the biogeographic events that led to the current geographic distribution of Paracoccidioides species and their sister species, Nested Clade and Likelihood Analysis of Geographic Range Evolution (LAGRANGE) analyses were applied. The radiation of Paracoccidioides started in northwest South America, around 11–32 million years ago, as calculated on the basis of ARF substitution rate, in the BEAST program. Vicariance was responsible for the divergence among S1, PS2 and P. lutzii and a recent dispersal generated the PS3 species, restricted to Colombia. Taking into account the ancestral areas revealed by the LAGRANGE analysis and the major geographic distribution of L. loboi in the Amazon basin, a region strongly affected by the Andes uplift and marine incursions in the Cenozoic era, we also speculate about the effect of these geological events on the vicariance between Paracoccidioides and L. loboi. Conclusions/Significance The use of at least 3 SNPs, but not morphological criteria, as markers allows us to distinguish among the four cryptic species of the genus Paracoccidioides. The work also presents a biogeographic study speculating on how these species might have diverged in South America, thus contributing to elucidating evolutionary aspects of the genus Paracoccidioides. PMID:22666382

Theodoro, Raquel Cordeiro; Teixeira, Marcus de Melo; Felipe, Maria Sueli Soares; Paduan, Karina dos Santos; Ribolla, Paulo Martins; San-Blas, Gioconda; Bagagli, Eduardo

2012-01-01

42

Transposable elements and two other molecular markers as typing tools for the genus Paracoccidioides.  

PubMed

Studies comparing Paracoccidioides brasiliensis and Paracoccidioides lutzii have shown that these fungi have significant genomic differences that may have implications in the clinical manifestation, diagnosis, and treatment of paracoccidioidomycosis caused by them. Thus, molecular typing methods are required that can distinguish between various species of Paracoccidioides. The aim of this study was to explore the potential use as molecular markers of the transposable elements Trem A-H recently identified and characterized in the genus Paracoccidioides as a means of differentiating the species. We take advantage of the abundance and distribution of these transposons in the Paracoccidioides genomes to develop a simple and highly reproducible polymerase chain reaction (PCR)-based technique. Furthermore we compare the performance of this test with two other molecular markers already in use to identify these fungi. PMID:25541559

Alves, Fernanda Lourenço; Ribeiro, Mariceli Araújo; Hahn, Rosane Christine; de Melo Teixeira, Marcus; de Camargo, Zoilo Pires; Cisalpino, Patrícia Silva; Marini, Marjorie Mendes

2015-02-01

43

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

44

Serology of Paracoccidioidomycosis Due to Paracoccidioides lutzii  

PubMed Central

Paracoccidioides lutzii is a new agent of paracoccidioidomycosis (PCM) and has its epicenter localized to the Central-West region of Brazil. Serological diagnosis of PCM caused by P. lutzii has not been established. This study aimed to develop new antigenic preparations from P. lutzii and to apply them in serological techniques to improve the diagnosis of PCM due to P. lutzii. Paracoccidioides lutzii exoantigens, cell free antigen (CFA), and a TCA-precipitated antigen were evaluated in immunodiffusion (ID) tests using a total of 89 patient sera from the Central-West region of Brazil. Seventy-two sera were defined as reactive for P. brasiliensis using traditional antigens (AgPbB339 and gp43). Non-reactive sera for traditional antigens (n?=?17) were tested with different P. lutzii preparations and P. lutzii CFA showed 100% reactivity. ELISA was found to be a very useful test to titer anti-P. lutzii antibodies using P. lutzii-CFA preparations. Sera from patients with PCM due to P. lutzii presented with higher antibody titers than PCM due to P. brasiliensis and heterologous sera. In western blot, sera from patients with PCM due to P. lutzii were able to recognize antigenic molecules from the P. lutzii-CFA antigen, but sera from patients with PCM due to P. brasiliensis could not recognize any P. lutzii molecules. Due to the facility of preparing P. lutzii CFA antigens we recommend its use in immunodiffusion tests for the diagnosis of PCM due to P. lutzii. ELISA and western blot can be used as complementary tests. PMID:25032829

Gegembauer, Gregory; Araujo, Leticia Mendes; Pereira, Edy Firmina; Rodrigues, Anderson Messias; Paniago, Anamaria Mello Miranda; Hahn, Rosane Christine; de Camargo, Zoilo Pires

2014-01-01

45

Occurrence of Paracoccidioides lutzii in the Amazon Region: Description of Two Cases  

PubMed Central

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; Messias Rodrigues, Anderson; de Hoog, G. Sybren; Silveira-Gomes, Fabíola; Pires de Camargo, Zoilo

2012-01-01

46

Transcriptional profile of Paracoccidioides spp. in response to itraconazole  

PubMed Central

Background Itraconazole is currently used to treat paracoccidioidomycosis. The mechanism of action of azoles has been elucidated in some fungi, although little is known regarding its mechanism of action in Paracoccidioides spp. The present work focused on identification of regulated transcripts using representational difference analysis of Paracoccidioides spp. yeast cells treated with itraconazole for 1 and 2 h. Results Paracoccidioides Pb01 genes up-regulated by itraconazole included genes involved in cellular transport, metabolism/energy, transcription, cell rescue, defense and virulence. ERG11, ERG6, ERG3, ERG5 and ERG25 were up-regulated at multiple time points. In vivo infection experiments in mice corroborated the in vitro results. Ergosterol levels and distribution were evaluated in Paracoccidioides Pb18 yeast cells, and the results demonstrate that both factors were changed in the fungus treated with itraconazole. Conclusion To our knowledge, this is the first transcriptional analysis of Paracoccidioides spp. exposed to a triazole drug. Here acetyl seems to be intensively produced from different metabolic pathways to produce ergosterol by the action of ergosterol synthesis related enzymes, which were also affected in other fungi. Among the genes affected, we identified genes in common with other fungi, as well as genes unique to Paracoccidioides Pb01. Those genes could be considered target to new drugs. Voltage-gated Ca2+ alpha subunit (CAV), Tetracycline resistance protein (TETA) and Hemolisyn-iii channel protein (HLYiii) were found only here and a probably involvement with resistence to itraconazole could be investigated in the future. However our findings do not permit inference to current clinical practice. PMID:24690401

2014-01-01

47

The diversity and extracellular enzymatic activities of yeasts isolated from water tanks of Vriesea minarum, an endangered bromeliad species in Brazil, and the description of Occultifur brasiliensis f.a., sp. nov.  

PubMed

The diversity of yeast species collected from the bromeliad tanks of Vriesea minarum, an endangered bromeliad species, and their ability to produce extracellular enzymes were studied. Water samples were collected from 30 tanks of bromeliads living in a rupestrian field site located at Serrada Piedade, Minas Gerais state, Brazil, during both the dry and rainy seasons. Thirty-six species were isolated, representing 22 basidiomycetous and 14 ascomycetous species. Occultifur sp., Cryptococcus podzolicus and Cryptococcus sp. 1 were the prevalent basidiomycetous species. The yeast-like fungus from the order Myriangiales, Candida silvae and Aureobasidium pullulans were the most frequent ascomycetous species. The diversity of the yeast communities obtained between seasons was not significantly different, but the yeast composition per bromeliad was different between seasons. These results suggest that there is significant spatial heterogeneity in the composition of populations of the yeast communities within bromeliad tanks, independent of the season. Among the 352 yeast isolates tested, 282 showed at least one enzymatic activity. Protease activity was the most widely expressed extracellular enzymatic activity, followed by xylanase, amylase, pectinase and cellulase activities. These enzymes may increase the carbon and nitrogen availability for the microbial food web in the bromeliad tank of V. minarum. Sequence analyses revealed the existence of 10 new species, indicating that bromeliad tanks are important sources of new yeasts. The novel species Occultifur brasiliensis, f.a., sp. nov., is proposed to accommodate the most frequently isolated yeast associated with V. minarum. The type strain of O. brasiliensis, f.a., sp. nov. is UFMG-CM-Y375(T) (= CBS 12687(T)). The Mycobank number is MB 809816. PMID:25515414

Gomes, Fátima C O; Safar, Silvana V B; Marques, Andrea R; Medeiros, Adriana O; Santos, Ana Raquel O; Carvalho, Cláudia; Lachance, Marc-André; Sampaio, José Paulo; Rosa, Carlos A

2015-02-01

48

Predicting copper-, iron-, and zinc-binding proteins in pathogenic species of the Paracoccidioides genus  

PubMed Central

Approximately one-third of all proteins have been estimated to contain at least one metal cofactor, and these proteins are referred to as metalloproteins. These represent one of the most diverse classes of proteins, containing metal ions that bind to specific sites to perform catalytic, regulatory and structural functions. Bioinformatic tools have been developed to predict metalloproteins encoded by an organism based only on its genome sequence. Its function and the type of metal binder can also be predicted via a bioinformatics approach. Paracoccidioides complex includes termodimorphic pathogenic fungi that are found as saprobic mycelia in the environment and as yeast, the parasitic form, in host tissues. They are the etiologic agents of Paracoccidioidomycosis, a prevalent systemic mycosis in Latin America. Many metalloproteins are important for the virulence of several pathogenic microorganisms. Accordingly, the present work aimed to predict the copper, iron and zinc proteins encoded by the genomes of three phylogenetic species of Paracoccidioides (Pb01, Pb03, and Pb18). The metalloproteins were identified using bioinformatics approaches based on structure, annotation and domains. Cu-, Fe-, and Zn-binding proteins represent 7% of the total proteins encoded by Paracoccidioides spp. genomes. Zinc proteins were the most abundant metalloproteins, representing 5.7% of the fungus proteome, whereas copper and iron proteins represent 0.3 and 1.2%, respectively. Functional classification revealed that metalloproteins are related to many cellular processes. Furthermore, it was observed that many of these metalloproteins serve as virulence factors in the biology of the fungus. Thus, it is concluded that the Cu, Fe, and Zn metalloproteomes of the Paracoccidioides spp. are of the utmost importance for the biology and virulence of these particular human pathogens.

Tristão, Gabriel B.; Assunção, Leandro do Prado; dos Santos, Luiz Paulo A.; Borges, Clayton L.; Silva-Bailão, Mirelle Garcia; Soares, Célia M. de Almeida; Cavallaro, Gabriele; Bailão, Alexandre M.

2015-01-01

49

Transcriptional profile of Paracoccidioides induced by oenothein B, a potential antifungal agent from the Brazilian Cerrado plant Eugenia uniflora  

PubMed Central

Background The compound oenothein B (OenB), which is isolated from the leaves of Eugenia uniflora, a Brazilian Cerrado plant, interferes with Paracoccidioides yeast cell morphology and inhibits 1,3-?-D-glucan synthase (PbFKS1) transcript accumulation, which is involved in cell wall synthesis. In this work we examined the gene expression changes in Paracoccidioides yeast cells following OenB treatment in order to investigate the adaptive cellular responses to drug stress. Results We constructed differential gene expression libraries using Representational Difference Analysis (RDA) of Paracoccidioides yeast cells treated with OenB for 90 and 180 min. Treatment for 90 min resulted in the identification of 463 up-regulated expressed sequences tags (ESTs) and 104 down-regulated ESTs. For the 180 min treatment 301 up-regulated ESTs and 143 down-regulated were identified. Genes involved in the cell wall biosynthesis, such as GLN1, KRE6 and FKS1, were found to be regulated by OenB. Infection experiments in macrophages corroborated the in vitro results. Fluorescence microscopy showed increased levels of chitin in cells treated with OenB. The carbohydrate polymer content of the cell wall of the fungus was also evaluated, and the results corroborated with the transcriptional data. Several other genes, such as those involved in a variety of important cellular processes (i.e., membrane maintenance, stress and virulence) were found to be up-regulated in response to OenB treatment. Conclusions The exposure of Paracoccidioides to OenB resulted in a complex altered gene expression profile. Some of the changes may represent specific adaptive responses to this compound in this important pathogenic fungus. PMID:24119145

2013-01-01

50

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, Cecília Maria Alves; Kato, Lucília; da Silva, Roosevelt Alves; Quintino, Guilherme Oliveira; do Desterro Cunha, Silvio; de Almeida Soares, Célia Maria; Pereira, Maristela

2014-01-01

51

Inhibition of paracoccidioides lutzii Pb01 isocitrate lyase by the natural compound argentilactone and its semi-synthetic derivatives.  

PubMed

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

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

2014-01-01

52

Detection of Paracoccidioides spp. in environmental aerosol samples.  

PubMed

Taking into account that paracoccidioidomycosis infection occurs by inhalation of the asexual conidia produced by Paracoccidioides spp. in its saprobic phase, this work presents the collection of aerosol samples as an option for environmental detection of this pathogen, by positioning a cyclonic air sampler at the entrance of armadillo burrows. Methods included direct culture, extinction technique culture and Nested PCR of the rRNA coding sequence, comprising the ITS1-5.8S-ITS2 region. In addition, we evaluated one armadillo (Dasypus novemcinctus) as a positive control for the studied area. Although the pathogen could not be isolated by the culturing strategies, the aerosol sampling associated with molecular detection through Nested PCR proved the best method for discovering Paracoccidioides spp. in the environment. Most of the ITS sequences obtained in this investigation proved to be highly similar with the homologous sequences of Paracoccidioides lutzii from the GenBank database, suggesting that this Paracoccidioides species may not be exclusive to mid-western Brazil as proposed so far. PMID:22762209

Arantes, Thales Domingos; Theodoro, Raquel Cordeiro; Da Graça Macoris, Severino Assis; Bagagli, Eduardo

2013-01-01

53

Transcriptional and Proteomic Responses to Carbon Starvation in Paracoccidioides  

PubMed Central

Background The genus Paracoccidioides comprises human thermal dimorphic fungi, which cause paracoccidioidomycosis (PCM), an important mycosis in Latin America. Adaptation to environmental conditions is key to fungal survival during human host infection. The adaptability of carbon metabolism is a vital fitness attribute during pathogenesis. Methodology/Principal Findings The fungal pathogen Paracoccidioides spp. is exposed to numerous adverse conditions, such as nutrient deprivation, in the human host. In this study, a comprehensive response of Paracoccidioides, Pb01, under carbon starvation was investigated using high-resolution transcriptomic (RNAseq) and proteomic (NanoUPLC-MSE) approaches. A total of 1,063 transcripts and 421 proteins were differentially regulated, providing a global view of metabolic reprogramming during carbon starvation. The main changes were those related to cells shifting to gluconeogenesis and ethanol production, supported by the degradation of amino acids and fatty acids and by the modulation of the glyoxylate and tricarboxylic cycles. This proposed carbon flow hypothesis was supported by gene and protein expression profiles assessed using qRT-PCR and western blot analysis, respectively, as well as using enzymatic, cell dry weight and fungus-macrophage interaction assays. The carbon source provides a survival advantage to Paracoccidioides inside macrophages. Conclusions/Significance For a complete understanding of the physiological processes in an organism, the integration of approaches addressing different levels of regulation is important. To the best of our knowledge, this report presents the first description of the responses of Paracoccidioides spp. to host-like conditions using large-scale expression approaches. The alternative metabolic pathways that could be adopted by the organism during carbon starvation can be important for a better understanding of the fungal adaptation to the host, because systems for detecting and responding to carbon sources play a major role in adaptation and persistence in the host niche. PMID:24811072

Lima, Patrícia de Sousa; Casaletti, Luciana; Bailão, Alexandre Melo; de Vasconcelos, Ana Tereza Ribeiro; Fernandes, Gabriel da Rocha; Soares, Célia Maria de Almeida

2014-01-01

54

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

55

Galleria mellonella as a model host to study Paracoccidioides lutzii and Histoplasma capsulatum  

PubMed Central

Non-mammalian models have been used to investigate fungal virulence. In this work we have explored the use of Galleria mellonella as an infection model for the pathogenic dimorphic fungi Histoplasma capsulatum and Paracoccidioides lutzii. In mammalian models these fungi cause similar infections, and disease outcomes are influenced by the quantity of the infective inocula. We describe a similar aspect in a G. mellonella model and characterize the pathogenesis features in this system. Infection with P. lutzii or H. capsulatum, in all inoculum used, killed larvae at 25 and 37°C. However, there was a lack of correlation between the number of yeast cells used for infection and the time to larvae death, which may indicate that the fungi induce protective responses in a dynamic manner as the lowest concentrations of fungi induced the most rapid death. For both fungi, the degree of larvae melanization was directly proportional to the inocula size, and this effect was visibly more apparent at 37°C. Histological evaluation of the larvae showed a correlation between the inoculum and granuloma-like formation. Our results suggest that G. mellonella is a potentially useful model to study virulence of dimorphic fungi. PMID:23302787

Thomaz, Luciana; García-Rodas, Rocío; Guimarães, Allan J.; Taborda, Carlos P.; Zaragoza, Oscar; Nosanchuk, Joshua D.

2013-01-01

56

Hydroxamate Production as a High Affinity Iron Acquisition Mechanism in Paracoccidioides Spp  

PubMed Central

Iron is a micronutrient required by almost all living organisms, including fungi. Although this metal is abundant, its bioavailability is low either in aerobic environments or within mammalian hosts. As a consequence, pathogenic microorganisms evolved high affinity iron acquisition mechanisms which include the production and uptake of siderophores. Here we investigated the utilization of these molecules by species of the Paracoccidioides genus, the causative agents of a systemic mycosis. It was demonstrated that iron starvation induces the expression of Paracoccidioides ortholog genes for siderophore biosynthesis and transport. Reversed-phase HPLC analysis revealed that the fungus produces and secretes coprogen B, which generates dimerumic acid as a breakdown product. Ferricrocin and ferrichrome C were detected in Paracoccidioides as the intracellular produced siderophores. Moreover, the fungus is also able to grow in presence of siderophores as the only iron sources, demonstrating that beyond producing, Paracoccidioides is also able to utilize siderophores for growth, including the xenosiderophore ferrioxamine. Exposure to exogenous ferrioxamine and dimerumic acid increased fungus survival during co-cultivation with macrophages indicating that these molecules play a role during host-pathogen interaction. Furthermore, cross-feeding experiments revealed that Paracoccidioides siderophores promotes growth of Aspergillus nidulans strain unable to produce these iron chelators. Together, these data denote that synthesis and utilization of siderophores is a mechanism used by Paracoccidioides to surpass iron limitation. As iron paucity is found within the host, siderophore production may be related to fungus pathogenicity. PMID:25157575

Silva-Bailão, Mirelle Garcia; Bailão, Elisa Flávia Luiz Cardoso; Lechner, Beatrix Elisabeth; Gauthier, Gregory M.; Lindner, Herbert; Bailão, Alexandre Melo; Haas, Hubertus; de Almeida Soares, Célia Maria

2014-01-01

57

Susceptibility of Sporothrix brasiliensis isolates to amphotericin B, azoles, and terbinafine.  

PubMed

The in vitro activity of the antifungal agents amphotericin B (AMB), itraconazole (ITC), posaconazole (PSC), voriconazole (VRC), and terbinafine (TRB) against 32 Brazilian isolates of Sporothrix brasiliensis, including 16 isolates from a recent (2011-2012) epidemic in Rio de Janeiro state, was examined. We describe and genotype new isolates and clustered them with 16 older (from 2004 or earlier) S. brasiliensis isolates by phylogenetic analysis. We tested both the yeast and the mycelium form of all isolates using broth microdilution methods based on the reference protocols M38-A2 and M27-A3 (recommended by the Clinical and Laboratory Standards Institute). Considering minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs), TRB was found to be the most active drug in vitro for both fungal forms, followed by PSC. Several isolates showed high MICs for AMB and/or ITC, which are currently used as first-line therapy for sporotrichosis. VRC displayed very low activity against S. brasiliensis isolates. The primary morphological modification observed on treated yeasts by transmission electron microscopy analysis was changes in cell wall. Our results indicate that TRB is the antifungal with the best in vitro activity against S. brasiliensis and support the use of TRB as a promising option for the treatment of cutaneous and/or lymphocutaneous sporotrichosis. PMID:25394542

Borba-Santos, Luana Pereira; Rodrigues, Anderson Messias; Gagini, Thalita Braga; Fernandes, Geisa Ferreira; Castro, Rafaela; de Camargo, Zoilo Pires; Nucci, Marcio; Lopes-Bezerra, Leila Maria; Ishida, Kelly; Rozental, Sonia

2014-11-13

58

Gene insertion into Hevea brasiliensis  

Microsoft Academic Search

A transformation system has been developed for Hevea brasiliensis using the particle gun method. Anther derived calluses were transformed with vectors harbouring the ß-glucuronidase (gus) gene, the neomycin phosphotransferase (nptII) gene, and the chloramphenicol acetyl transferase (cat) gene. Gene transfer was determined by histochemical staining and fluorometric assay for ß-glucuronidase activity, enzyme linked immunosorbent assay for detecting neomycin phosphotransferase II

P. Arokiaraj; H. Jones; K. F. Cheong; S. Coomber; B. V. Charlwood

1994-01-01

59

Cross-Reactivity of Paracoccidioides brasiliensis, Histoplasma capsulatum, and Cryptococcus Species in the Commercial Platelia Aspergillus Enzyme Immunoassay?  

PubMed Central

Cross-reactivity in the Platelia Aspergillus enzyme immunoassay was evaluated using 120 sera from patients with paracoccidioidomycosis, histoplasmosis, and cryptococcosis. At a cutoff value of 0.5, positivity rates were 50%, 67%, and 50%, respectively. The implications for these findings are discussed. PMID:19020109

Xavier, Melissa O.; Pasqualotto, Alessandro C.; Cardoso, Isabel Cristina E.; Severo, Luiz Carlos

2009-01-01

60

Cloning and characterisation of JAZ gene family in Hevea brasiliensis.  

PubMed

Mechanical wounding or treatment with exogenous jasmonates (JA) induces differentiation of the laticifer in Hevea brasiliensis. JA is a key signal for latex biosynthesis and wounding response in the rubber tree. Identification of JAZ (jasmonate ZIM-domain) family of proteins that repress JA responses has facilitated rapid progress in understanding how this lipid-derived hormone controls gene expression and related physiological processes in plants. In this work, the full-length cDNAs of six JAZ genes were cloned from H. brasiliensis (termed HbJAZ). These HbJAZ have different lengths and sequence diversity, but all of them contain Jas and ZIM domains, and two of them contain an ERF-associated amphiphilic repression (EAR) motif in the N-terminal. Real-time RT-PCR analyses revealed that HbJAZ have different expression patterns and tissue specificity. Four HbJAZ were up-regulated, one was down-regulated, while two were less effected by rubber tapping treatment, suggesting that they might play distinct roles in the wounding response. A yeast two-hybrid assay revealed that HbJAZ proteins interact with each other to form homologous or heterogeneous dimer complexes, indicating that the HbJAZ proteins may expand their function through diverse JAZ-JAZ interactions. This work lays a foundation for identification of the JA signalling pathway and molecular mechanisms of latex biosynthesis in rubber trees. This article is protected by copyright. All rights reserved. PMID:25399518

Hong, Hao; Xiao, Hua; Yuan, Hongmei; Zhai, Jinling; Huang, Xi

2014-11-14

61

Amphotericin B, alone or followed by itraconazole therapy, is effective in the control of experimental disseminated sporotrichosis by Sporothrix brasiliensis.  

PubMed

Sporothrix brasiliensis is a highly virulent member of the S. schenckii complex, which is responsible for the emergence of the epidemic sporotrichosis in southeastern Brazil over the last two decades. There are no in vivo studies on the sensitivity of S. brasiliensis to the therapeutic regimens used to treat sporotrichosis. Here, we evaluated the efficacy and safety of antifungal treatments against S. brasiliensis using a murine model of disseminated sporotrichosis. In vitro, S. brasiliensis yeasts were sensitive to low concentrations of amphotericin B-deoxycholate (AMB-d) and itraconazole (ITZ), the latter having greater selectivity toward the fungus. The following treatment regimens were tested in vivo: intravenous AMB-d for 7 days post-infection (p.i.), oral ITZ for up to 30 days p.i., and AMB-d followed by ITZ (AMB-d/ITZ). AMB-d and AMB-d/ITZ led to 100% survival of infected mice at the end of the 45-day experimental period. Although all treatments extended mice survival, only AMB-d and AMB-d/ITZ significantly reduced fungal load in all organs, but AMB-d/ITZ led to a more consistent decrease in overall fungal burden. No treatment increased the levels of serum toxicity biomarkers. Taken together, our results indicate that AMB-d/ITZ is the best therapeutic option for controlling disseminated sporotrichosis caused by S. brasiliensis. PMID:25306202

Ishida, Kelly; de Castro, Rafaela Alves; Borba Dos Santos, Luana Pereira; Quintella, Leonardo Pereira; Lopes-Bezerra, Leila M; Rozental, Sonia

2015-01-01

62

?-Carboline Alkaloids from Galianthe ramosa Inhibit Malate Synthase from Paracoccidioides spp.  

PubMed

As part of our continuing chemical and biological analyses of Rubiaceae species from Cerrado, we isolated novel alkaloids 1 and 2, along with known compounds epicatechin, ursolic acid, and oleanolic acid, from Galianthe ramosa. Alkaloid 2 inhibited malate synthase from the pathogenic fungus Paracoccidioides spp. This enzyme is considered an important molecular target because it is not found in humans. Molecular docking simulations were used to describe the interactions between the alkaloids and malate synthase. PMID:25412318

de Freitas, Carla S; Kato, Lucilia; de Oliveira, Cecília M A; Queiroz, Luiz H K; Santana, Mábio J; Schuquel, Ivânia T; Delprete, Piero G; da Silva, Roosevelt A; Quintino, Guilherme O; da Silva Neto, Benedito R; Soares, Célia M A; Pereira, Maristela

2014-12-01

63

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

64

The multifaceted roles of metabolic enzymes in the Paracoccidioides species complex  

PubMed Central

Paracoccidioides species are dimorphic fungi and are the etiologic agents of paracoccidioidomycosis, which is a serious disease that involves multiple organs. The many tissues colonized by this fungus suggest a variety of surface molecules involved in adhesion. A surprising finding is that most enzymes in the glycolytic pathway, tricarboxylic acid (TCA) cycle and glyoxylate cycle in Paracoccidioides spp. have adhesive properties that aid in interacting with the host extracellular matrix and thus act as ‘moonlighting’ proteins. Moonlighting proteins have multiple functions, which adds a dimension to cellular complexity and benefit cells in several ways. This phenomenon occurs in both eukaryotes and prokaryotes. For example, moonlighting proteins from the glycolytic pathway or TCA cycle can play a role in bacterial pathogenesis by either acting as proteins secreted in a conventional pathway and/or as cell surface components that facilitate adhesion or adherence. This review outlines the multifunctionality exhibited by many Paracoccidioides spp. enzymes, including aconitase, aldolase, glyceraldehyde-3-phosphate dehydrogenase, isocitrate lyase, malate synthase, triose phosphate isomerase, fumarase, and enolase. We discuss the roles that moonlighting activities play in the virulence characteristics of this fungus and several other human pathogens during their interactions with the host.

Marcos, Caroline M.; de Oliveira, Haroldo C.; da Silva, Julhiany de F.; Assato, Patrícia A.; Fusco-Almeida, Ana M.; Mendes-Giannini, Maria J. S.

2014-01-01

65

Enzyme-linked immunosorbent assay (ELISA) in the paracoccidioidomycosis  

Microsoft Academic Search

An enzyme-linked immunosorbent assay (ELISA) for detection and quantification of antibodies antiParacoccidioides brasiliensis is described. Polystyrene plates have been used as solid phase to absorb P. brasiliensis metabolic yeast phase antigen. Twenty sera of proven paracoccidioidomycosis, 11 of histoplasmosis due Histoplasma capsulatum, 20 of aspergillosis and 20 human normal sera were tested. Ninety-five percent of the paracoccidioidomycosis sera had O.D.

Z. Pires de Camargo; J. L. Guesdon; E. Drouhet; L. Improvisi

1984-01-01

66

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

67

Thyroid peroxidase inhibition by Kalanchoe brasiliensis aqueous extract.  

PubMed

Flavonoids are known inhibitors of thyroid peroxidase (TPO) and some are components of Kalanchoe brasiliensis, a plant used in popular medicine to treat tissue injuries, enlarged ganglia and peptic ulcer. As K. brasiliensis extract is currently used, the present study was designed to evaluate the effects of K. brasiliensis aqueous extract on TPO activity. We show here that TPO iodide-oxidation activity was significantly inhibited by K. brasiliensis aqueous extract and that TPO inhibition seems to be competitive, since the enzyme V(max) was unchanged and K(m) for iodide was significantly increased in the presence of the plant extract. Furthermore, TPO inhibitory activity produced by K. brasiliensis extract was unchanged after boiling or by incubation with hepatic enzymes (activated S9 fraction), suggesting that at least the antithyroid component of this plant infusion could probably reach systemic circulation. We also report that K. brasiliensis aqueous extract is able to scavenge H(2)O(2), in vitro. As H(2)O(2) is an essential TPO cofactor, it is possible that the H(2)O(2) trapping effect of K. brasiliensis may be responsible, at least in part, for the inhibition of the iodide-oxidation reaction catalysed by this enzyme. Thus, K. brasiliensis aqueous extract has antithyroid effects in vitro, suggesting that its chronic consumption could contribute to the development of goitre and hypothyroidism, mainly in areas of low iodine intake. PMID:10762727

Ferreira, A C; Rosenthal, D; Carvalho, D P

2000-05-01

68

ANTIGENIC ANALYSES OF THE ADULT WORMS OF NIPPOSTRONGYLUS BRASILIENSIS  

E-print Network

ANTIGENIC ANALYSES OF THE ADULT WORMS OF NIPPOSTRONGYLUS BRASILIENSIS BY CROSSED brasiliensis result in expulsion of the adult worm population (Ogilvie, 1964; Barth et al., 1966; Luffau, 19691 of the infection in hypo- thymic nu/nu mice (Mitchell et al., 1976); b) by the normal expulsion of the worms from

Paris-Sud XI, Université de

69

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, ...

70

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

71

The function of Rad6 gene in Hevea brasiliensis extends beyond DNA repair.  

PubMed

The Rad6 gene of Saccharomyces cerevisiae encodes an ubiquitin-conjugating enzyme (E2) which is required for DNA repair, damage-induced mutagenesis, sporulation, etc. In this study, one Rad6 homolog, designated HbRad6, was cloned in rubber tree (Hevea brasiliensis). The putative protein sequence of HbRad6 contains 152 amino acids, a conserved UBC domain, and a conserved active-site cysteine in the UBC domain, which is required for E2 enzymes catalytic activity. HbRad6 shared high similarity with Rad6 from other species. It shared the highest similarity with rice OsRad6 and Arabidopsis thaliana AtUBC2 with 96.05% identical residues, and 63.16% sequence identity with yeast Rad6 (excluding the acidic tail). Comparing expression among different Hevea tissues demonstrated that HbRad6 was ubiquitously expressed in all tissues, but it revealed a preferential expression in the latex. Furthermore, HbRad6 expression was markedly induced by DNA-damaging agent H2O2, the latex stimulator ethephon (ET), and methyl jasmonate (MeJA), while NaCl and wounding treatments had relatively minor effect upon its expression. Genetic complementation experiment revealed that HbRad6 had minor effects on the complementation of the UV sensitivity of yeast rad6 null mutant, indicating that the Hevea Rad6 protein may partially suppress the UV sensitivity of the yeast rad6 mutant. These results suggested that HbRad6 was a multifunction gene involved in DNA damage repair, hormones and stress responses in rubber tree. PMID:23500716

Qin, Bi

2013-05-01

72

Melatonin production in the sea star Echinaster brasiliensis (Echinodermata).  

PubMed

The primary hormone of the vertebrate pineal gland, melatonin, has been identified broadly throughout the tree of life, in animals, plants, and fungi, supporting a deep evolutionary origin for this signaling molecule. However, some key groups have not been studied. Echinoderms, deuterostome animals, are one of these groups. Herein we study the presence of melatonin and enzymes of its pathway in the sea star Echinaster brasiliensis. We demonstrate that E. brasiliensis produces endogenous melatonin, in the gonads, under a circadian pattern with a nocturnal peak of production. We also show that the enzymes arylalkylamine N-acetyltransferase (AANAT) and tryptophan hydroxylase (TPH) are present and are probably regulating the melatonin production. PMID:24797096

Peres, Rafael; Amaral, Fernanda Gaspardo; Marques, Antonio Carlos; Neto, José Cipolla

2014-04-01

73

Disseminated paracoccidioidomycosis in a Southern two-toed sloth (Choloepus didactylus).  

PubMed

A Southern two-toed sloth (Choloepus didactylus), originally acquired from French Guiana, died while maintained in quarantine in a pet store in Monterrey, Mexico. Large yeast cells with multiple buds compatible with Paracoccidioides brasiliensis were observed in disseminated granulomatous lesions in the lungs, liver, spleen and kidney. Transmission electron microscopical examination supported the diagnosis. This is the first report of paracoccidioidomycosis in a two-toed sloth. PMID:20961559

Trejo-Chávez, A; Ramírez-Romero, R; Ancer-Rodríguez, J; Nevárez-Garza, A M; Rodríguez-Tovar, L E

2011-01-01

74

A Feast for Yeast  

NSDL National Science Digital Library

In this activity on page 6 of the PDF, learners investigate yeast. Learners prepare an experiment to observe what yeast cells like to eat. Learners feed the yeast cells various ingredients in plain bread--water, flour, sugar, and salt--to discover yeast's favorite food.

Society, American C.

2000-01-01

75

Yeast-Air Balloons  

NSDL National Science Digital Library

In this activity, learners make a yeast-air balloon to get a better idea of what yeast can do. Learners discover that the purpose of leaveners like yeast is to produce the gas that makes bread rise. Learners discover that as yeast feeds on sugar, it produces carbon dioxide which slowly fills the balloon.

The Exploratorium

2012-03-10

76

Temporal Dynamics of Reproduction in Hemiramphus brasiliensis (Osteichthyes: Hemiramphidae)  

PubMed Central

The reproductive aspects of Hemiramphus brasiliensis were analyzed with a view to verify the temporal dynamics of reproduction. This paper presents data on sex ratio, length at first sexual maturity, macroscopic and histological aspects of gonad development, gonadosomatic index (GSI), reproductive period, and fecundity of H. brasiliensis. The fishes were captured from the coastal waters of Rio Grande do Norte, northeastern Brazil. Females of this species predominated in the sampled population and were larger in size than the males. The length at the first sexual maturation of males was 20.8?cm and that of females was 21.5?cm. The macroscopic characteristics of the gonads indicated four maturation stages. Histological studies of gonads of H. brasiliensis showed six phases of oocyte development and four phases of spermatocyte development. The batch fecundity of this species was 1153 (±258.22) mature oocytes for 50?g body weight of female. The microscopic characteristics of gonad development indicate that H. brasiliensis is a multiple spawner, presenting a prolonged reproductive period during the whole year, with a peak in the month of April, and is considered as an opportunistic strategist. PMID:25512946

de Oliveira, Mônica Rocha

2014-01-01

77

ANIMAL MODEL OF NIPPOSTRONGYLUS BRASILIENSIS AND HELIGMOSOMOIDES POLYGYRUS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Animal models of Nippostrongylus brasiliensis and Heligmosomoides polygyrus infection are powerful tools for the investigation of the basic biology of immune responses and protective immunity. In particular they model the induction and maintenance of Th2 type immune responses and exhibiting all the ...

78

Homologous Hevea brasiliensis REF (Hevb1) and SRPP (Hevb3) present different auto-assembling.  

PubMed

HbREF and HbSRPP are two Hevea brasiliensis proteins present on rubber particles, and probably involved in the coagulation of latex. Their function is unclear, but we previously discovered that REF had amyloid properties, which could be of particular interest during the coagulation process. First, we confirmed that REF and SRPP, homologous and principal proteins in hevea latex, are not glycoproteins. In this work, we investigated various aspects of protein interactions: aggregation, auto-assembling, yeast and erythrocyte agglutination, co-interactions by various biochemical (PAGE, spectroscopy, microscopy), biophysical (DLS, ellipsometry) and structural (TEM, ATR-FTIR, PM-IRRAS) approaches. We demonstrated that both proteins are auto-assembling into different aggregative states: REF polymerizes as an amyloid rich in ?-sheets and forms quickly large aggregates (>?m), whereas SRPP auto-assembles in solution into stable nanomultimers of a more globular nature. Both proteins are however able to interact together, and SRPP may inhibit the amyloidogenesis of REF. REF is also able to interact with the membranes of yeasts and erythrocytes, leading to their agglutination. In addition, we also showed that both REF and SRPP did not have antimicrobial activity, whereas their activity on membranes has been clearly evidenced. We may suspect that these aggregative properties, even though they are clearly different, may occur during coagulation, when the membrane is destabilized. The interaction of proteins with membranes could help in the colloidal stability of latex, whereas the protein-protein interactions would contribute to the coagulation process, by bringing rubber particles together or eventually disrupting the particle monomembranes. PMID:24239687

Berthelot, Karine; Lecomte, Sophie; Estevez, Yannick; Coulary-Salin, Bénédicte; Peruch, Frédéric

2014-02-01

79

Behavioral and Ecological Influences on the Echolocation of Brazilian Free-Tailed Bats, Tadarida brasiliensis.  

E-print Network

??This dissertation investigates variability in the echolocation calls of Brazilian free-tailed bats, Tadarida brasiliensis (Chiroptera: Molossidae), and explores how bats adjust echolocation call structure in… (more)

Gillam, Erin H

2007-01-01

80

Yeast Education Network  

NSDL National Science Digital Library

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

81

Laticifer-Specific Gene Expression in Hevea Brasiliensis (Rubber Tree)  

Microsoft Academic Search

Natural rubber, cis-1,4-polyisoprene, is obtained from a colloidal fluid called latex, which represents the cytoplasmic content of the laticifers of the rubber tree (Hevea brasiliensis). We have developed a method of extracting translatable mRNA from freshly tapped latex. Analysis of in vitro translation products of latex mRNA showed that the encoded polypeptides are very different from those of leaf mRNA

Anil Kush; Elisabeth Goyvaerts; Mee-Len Chye; Nam-Hai Chua

1990-01-01

82

Callus friability and somatic embryogenesis in Hevea brasiliensis  

Microsoft Academic Search

The influence of plant growth regulators, sucrose, calcium and various macronutrient media on callus friability and somatic\\u000a embryogenesis was investigated inHevea brasiliensis Mll. Arg. Friable and embryogenic calli were spontaneously formed in two rubber tree clones (PR 107 and RRIM 600) on the\\u000a Medium for Hevea (MH), with 3,4-dichlorophenoxyacetic acid (3,4-d), kinetin and sucrose, while compact embryogenic calli were enhanced

Pascal Montoro; Hervé Etienne; Nicole Michaux-Ferrière; Marc-Philippe Carron

1993-01-01

83

The pathogenic potential of the Lichtheimia genus revisited: Lichtheimia brasiliensis is a novel, non-pathogenic species.  

PubMed

Lichtheimia brasiliensis was recently described as a novel species within the genus Lichtheimia, which comprises a total of six species. L. brasiliensis was first reported from soil in Brazil. The aim of the study was to determine the relative virulence potential of L. brasiliensis using an avian infection model based on chicken embryos. PMID:25267009

Schwartze, Volker U; de A Santiago, André Luiz C M; Jacobsen, Ilse D; Voigt, Kerstin

2014-12-01

84

Genetic homogeneity and historical expansions of the slipper lobster, Scyllarides brasiliensis, in the south-west  

E-print Network

Genetic homogeneity and historical expansions of the slipper lobster, Scyllarides brasiliensis and population dynamics. The Brazilian slipper lobster, Scyllarides brasiliensis, is one of the most commercially important slipper lobster species in South America. We investigated, for the first time, the population

Solé-Cava, Antonio M.

85

Revalidation and redescription of Triatoma brasiliensis macromelasoma Galvão, 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, Nathália Cordeiro; Neiva, Vanessa Lima; Gonçalves, Teresa Cristina Monte; Felix, Márcio

2013-01-01

86

Population Growth in Yeasts  

NSDL National Science Digital Library

This lesson is the second of two that explore cellular respiration and population growth in yeasts. In the first lesson, students set up a simple way to indirectly observe and quantify the amount of respiration occurring in yeast-molasses cultures. Based on questions that arose during the first lesson and its associated activity, students in this lesson work in small groups to design experiments that determine how environmental factors affect yeast population growth.

Engineering K-Phd Program

87

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

88

Insecticide detection through protein engineering of Nippostrongylus brasiliensis acetylcholinesterase B.  

PubMed

The sensitivity of acetylcholinesterase (AChE) biosensors for insecticide detection could be increased substantially by engineering AChE B of Nippostrongylus brasiliensis. The introduction of 10 single and 4 double mutations into the AChE peptide chain led to an increase in sensitivity to 10 of the 11 insecticides tested. The combination of three mutants with the wild-type enzyme in a multienzyme biosensor array enabled the detection of 11 out of the 14 most important organophosphates and carbamates at concentrations below 10 microg/kg, the maximum residue limit of infant food. The detection limit for pirimiphos methyl could be reduced from 10 microg/L to a value as low as 1 ng/L (3.5 x 10(-)(12) mol/L). The newly created biosensors exhibited an extraordinary high storage stability. There was no loss of sensitivity of N. brasiliensis AChE B, immobilized on screen-printed, disposable electrodes, even after 17-month storage at room temperature. PMID:16159111

Schulze, Holger; Muench, Susanne B; Villatte, Francois; Schmid, Rolf D; Bachmann, Till T

2005-09-15

89

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

90

Moonlighting Proteins in Yeasts  

PubMed Central

Proteins able to participate in unrelated biological processes have been grouped under the generic name of moonlighting proteins. Work with different yeast species has uncovered a great number of moonlighting proteins and shown their importance for adequate functioning of the yeast cell. Moonlighting activities in yeasts include such diverse functions as control of gene expression, organelle assembly, and modification of the activity of metabolic pathways. In this review, we consider several well-studied moonlighting proteins in different yeast species, paying attention to the experimental approaches used to identify them and the evidence that supports their participation in the unexpected function. Usually, moonlighting activities have been uncovered unexpectedly, and up to now, no satisfactory way to predict moonlighting activities has been found. Among the well-characterized moonlighting proteins in yeasts, enzymes from the glycolytic pathway appear to be prominent. For some cases, it is shown that despite close phylogenetic relationships, moonlighting activities are not necessarily conserved among yeast species. Organisms may utilize moonlighting to add a new layer of regulation to conventional regulatory networks. The existence of this type of proteins in yeasts should be taken into account when designing mutant screens or in attempts to model or modify yeast metabolism. PMID:18322039

Gancedo, Carlos; Flores, Carmen-Lisset

2008-01-01

91

Alcoholic Fermentation in Yeast  

NSDL National Science Digital Library

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

Ingrid Waldron

92

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

93

Yeast Alive! Watch Yeast Live and Breathe  

NSDL National Science Digital Library

This lesson for Grades 6-8 explores the chemical reaction that happens when yeast makes bread rise. The process, called fermentation, occurs when tiny living organisms (yeast) feed on the sugars in flour dough, expelling carbon dioxide as they go. It promotes understanding of how enzymes can cause chemical reactions. This resource combines a 4-minute video of the process plus a hands-on lab that allows students to see the effects of fermentation within a typical 40-45 minute middle school class period.

2011-08-19

94

National Plant Diagnostic Network, Taxonomic training videos: Aphids under the microscope - Cerataphis brasiliensis  

Technology Transfer Automated Retrieval System (TEKTRAN)

Training is a critical part of aphid (Hemiptera: Aphididae) identification. This video provides provides training to identify the palm aphid, Cerataphis brasiliensis, using a compound microscope and an electronic identification key called “LUCID.” The video demonstrates key morphological structures...

95

Phylogenetic analysis reveals a high prevalence of Sporothrix brasiliensis in feline sporotrichosis outbreaks.  

PubMed

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, Tânia Maria Pacheco; Pereira, Sandro Antonio; Fernandes, Geisa Ferreira; Bezerra, Leila Maria Lopes; Felipe, Maria Sueli; de Camargo, Zoilo Pires

2013-01-01

96

Effect of intestinal erythrocyte agglutination on the feeding performance of Triatoma brasiliensis (Hemiptera: Reduviidae).  

PubMed

Triatoma brasiliensis is an important vector of Trypanosoma cruzi in Brazil. The feeding efficiency on its hosts depends on several parameters including the maintenance of the ingested blood at low viscosity, which could be modulated by the anterior midgut (crop) anticoagulant and haemagglutinant activities. In the present study, we characterized T. brasiliensis crop haemagglutination activity and evaluated its importance in the feeding process. Soluble crop contents (SCC) of T. brasiliensis were able to agglutinate rat, mouse and rabbit eryhtrocytes, but had no activity on cattle and Thrichomys apereoides, a rodent species commonly associated with T. brasiliensis in the wild. The haemagglutination was characterized by the immediate formation of several clusters of erythrocytes connected by flexible elastic-like fibers. The feeding efficiency of T. brasiliensis on rat (agglutinated by SCC) was almost double that from T. apereoides (not agglutinated by SCC). The influence of haemagglutination on feeding was confirmed by artificially feeding bugs on a diet composed of cattle or rat erythrocytes. The bugs fed on cattle erythrocytes had lower ingestion rates in comparison to those fed on rats. The results indicate that, in addition to other parameters, haemagglutination brought about by SCC has an important role in the feeding efficiency of T. brasiliensis. PMID:19524588

Araujo, Ricardo N; Pereira, Marcos H; Soares, Adriana C; Pereira, Iancor D C A; Diotaiuti, Liléia; Gontijo, Nelder F; Lehane, Michael J; Guarneri, Alessandra A

2009-09-01

97

Complete mitochondrial genome of Salminus brasiliensis (Characiformes, Characidae).  

PubMed

Abstract We report the complete mitochondrial genome of the fish Salminus brasiliensis, popularly known as dourado. It is a circular, 17,721?bp long DNA molecule, containing 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and a non-coding Control Region of 2128?bp, a relatively large molecule when compared to other closely related fishes. All protein-coding genes are on the heavy strand, except for Nd6, and all have ATG as the start codon, except for Cox1 gene which has a GTG start codon. Seven protein-coding genes have incomplete stop codons (Nd2, Cox2, Atp6, Nd4, and Cytb have T-?-, and Cox3 and Nd3 have TA-). TAG is the stop codon for Nd6 and AGG is the stop codon for Cox1. PMID:25208163

Brandão-Dias, Pedro Ferreira Pinto; Carmo, Anderson Oliveira do; Martins, Ana Paula Vimieiro; Pimenta, Ricardo José Gonzaga; Alves, Carlos Bernardo Mascarenhas; Kalapothakis, Evanguedes

2014-09-10

98

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.

99

Vaginal Yeast Infection  

MedlinePLUS

... caused by an overgrowth of a fungus called Candida albicans in the vagina. Candida is yeast, which is a type of fungus. ... small numbers, and symptoms only appear with overgrowth. Candida can multiply when an imbalance occurs, such as ...

100

Yeast infections (image)  

MedlinePLUS

Yeast infections may follow a course of antibiotics that were prescribed for another purpose. The antibiotics change the normal "balance" between organisms in the vagina by suppressing the growth of protective bacteria that normally have an antifungal effect.

101

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

102

Yeast expression platforms  

Microsoft Academic Search

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

Erik Böer; Gerhard Steinborn; Gotthard Kunze; Gerd Gellissen

2007-01-01

103

Forces in yeast flocculation  

NASA Astrophysics Data System (ADS)

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

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

2015-01-01

104

Forces in yeast flocculation.  

PubMed

In the baker's yeast Saccharomyces cerevisiae, cell-cell adhesion ("flocculation") is conferred by a family of lectin-like proteins known as the flocculin (Flo) proteins. Knowledge of the adhesive and mechanical properties of flocculins is important for understanding the mechanisms of yeast adhesion, and may help controlling yeast behaviour in biotechnology. We use single-molecule and single-cell atomic force microscopy (AFM) to explore the nanoscale forces engaged in yeast flocculation, focusing on the role of Flo1 as a prototype of flocculins. Using AFM tips labelled with mannose, we detect single flocculins on Flo1-expressing cells, showing they are widely exposed on the cell surface. When subjected to force, individual Flo1 proteins display two distinct force responses, i.e. weak lectin binding forces and strong unfolding forces reflecting the force-induced extension of hydrophobic tandem repeats. We demonstrate that cell-cell adhesion bonds also involve multiple weak lectin interactions together with strong unfolding forces, both associated with Flo1 molecules. Single-molecule and single-cell data correlate with microscale cell adhesion behaviour, suggesting strongly that Flo1 mechanics is critical for yeast flocculation. These results favour a model in which not only weak lectin-sugar interactions are involved in yeast flocculation but also strong hydrophobic interactions resulting from protein unfolding. PMID:25515338

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

2015-01-22

105

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

106

Yeast killer toxins and dimorphism.  

PubMed Central

The differential action of four selected yeast killer toxins on the mycelial and yeast forms of four isolates of the dimorphic fungus Sporothrix schenckii was comparatively evaluated. The results confirmed that the yeast killer phenomenon is present among hyphomycetes and yeasts and that both morphological forms of S. schenckii are susceptible to the action of the same yeast killer toxin. Quantitative differences in the response to the killer action of the mycelial and yeast forms in individual strains were also observed. To avoid retroconversion of the dimorphic forms, we used a modification of the conventional killer system. Images PMID:2754015

Polonelli, L; Conti, S; Campani, L; Morace, G; Fanti, F

1989-01-01

107

21 CFR 172.896 - Dried yeasts.  

Code of Federal Regulations, 2010 CFR

...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 total folic acid content of the yeast does not exceed 0.04 milligram...

2010-04-01

108

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

109

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 Central

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.

2013-01-01

110

Oxygen requirements of yeasts.  

PubMed

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. PMID:2082825

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

1990-12-01

111

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

112

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

113

Fish passage ladders from Canoas Complex - Paranapanema River: evaluation of genetic structure maintenance of Salminus brasiliensis (Teleostei: Characiformes)  

Microsoft Academic Search

The aim of this study, utilizing RAPD techniques, was to determine the genetic variability of Salminus brasiliensis groups collected at passage ladders of the hydroelectric plants (HEP) Canoas I and Canoas II - Paranapanema River (Brazil), as well as to estimate the population structure through different parameters of genetic diversity. The data obtained allowed us to conclude that S. brasiliensis

Carla Martins Lopes; Fernanda Simões de Almeida; Mário Luís Orsi; Sandro Geraldo de Castro Britto; Rodolfo Nardez Sirol; Leda Maria Koelblinger Sodré

2007-01-01

114

Alterations in hexose, amino acid and peptide transporter expression in intestinal epithelial cells during Nippostrongylus brasiliensis infection in the rat  

Microsoft Academic Search

Infection with the nematode Nippostrongylus brasiliensis induces various types of cytological alterations in the intestinal villus epithelium. The aim of this study was to analyse the expression of hexose, peptide and amino acid transporters in the small intestinal epithelium after infection. Brown-Norway rats were infected with 2000 N. brasiliensis L3 larvae and villus epithelial cells were isolated at various time

Shyuji Sekikawa; Yuichi Kawai; Atsushi Fujiwara; Kazutoshi Takeda; Tatsuya Tegoshi; Ryuichi Uchikawa; Minoru Yamada; Naoki Arizono

2003-01-01

115

Sporotrichosis in Rio de Janeiro, Brazil: Sporothrix brasiliensis Is Associated with Atypical Clinical Presentations  

PubMed Central

Background There have been several recent changes in the taxonomy of Sporothrix schenckii as well as new observations regarding the clinical aspects of sporotrichosis. In this study, we determined the identification of the Sporothrix species associated with both classic and unusual clinical aspects of sporotrichosis observed in the endemic area of sporotrichosis in Rio de Janeiro, Brazil. Methodology/Principal Findings To verify whether S. brasiliensis is associated with clinical manifestations of sporotrichosis, a cross-sectional study was performed in which Sporothrix isolates from 50 patients with different clinical manifestations were analyzed and their isolates were studied by phenotypic and genotypic methods. Data from these patients revealed a distinct clinical picture and therapeutic response in infections caused by Sporothrix brasiliensis (n?=?45) compared to patients with S. schenckii sensu stricto (n?=?5). S. brasiliensis was associated with disseminated cutaneous infection without underlying disease, hypersensitivity reactions, and mucosal infection, whereas patients with S. schenckii presented with less severe and more often localized disease, similar to the majority of previously described sporotrichosis cases. Interestingly, S. brasiliensis-infected patients overall required shorter durations of itraconazole (median 16 weeks) compared to the individuals with S. schenckii (median 24 weeks). Conclusions/Significance These findings suggest that Sporothrix species are linked to different clinical manifestations of sporotrichosis and that S. brasiliensis is effectively treated with oral itraconazole. PMID:25233227

Almeida-Paes, Rodrigo; de Oliveira, Manoel Marques Evangelista; Freitas, Dayvison Francis Saraiva; do Valle, Antônio Carlos Francesconi; Zancopé-Oliveira, Rosely Maria; Gutierrez-Galhardo, Maria Clara

2014-01-01

116

Vaginal Yeast Infections (For Parents)  

MedlinePLUS

... a common infection caused by a yeast called candida albicans (a type of fungus). Yeast infections usually ... the vagina, it is known as vulvovaginal candidiasis . Candida can overgrow for many reasons. Stress, pregnancy, and ...

117

Virtual Yeast Cell  

NSDL National Science Digital Library

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

118

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

119

Genetics of Yeasts  

NASA Astrophysics Data System (ADS)

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

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

120

Biological control of Rigidoporus lignosus in Hevea brasiliensis in Nigeria.  

PubMed

The study was conducted to evaluate in vitro and in vivo control of fungal antagonists on Rigidoporus lignosus (klotzsch) Imaz in Hevea brasiliensis (Willd. ex A. Juss.) Muell. Arg. in the rain forest zone of Nigeria. In vitro assessments of biological agents were carried out in dixenic cultures in Petri plates. In vivo tests were carried out in the nursery using Hypocrea virens and Hypocrea jecorina. Significant differences were observed with the dual inoculations of fungal antagonists and R. lignosus inoculated the same day, and the antagonists inoculated 24 h before inoculation of R. lignosus. Hypocrea jecorina was most effective in the control of R. lignosus with percentage inhibition of 86.83 %. Hypocrea virens, H. jecorina, Trichoderma spirale, Trichoderma sp., Trichoderma sp. Pers, and Hypocrea lixii were effective on R. lignosus. Fungal antagonists inoculated 24 h before inoculation of R. lignosus exhibited higher inhibitory efficacies than antagonists and R. lignosus inoculated the same day. In the in vivo evaluation of fungi antagonists on R. lignosus, seedlings in H. jecorina treatment at 60 d and H. virens treatment at 150 d after inoculations respectively had the highest plant heaths (highest length of stem and length of tap rot, lowest plant death, and least foliar symptom) compared to the control. Mortality rate was higher at 60 d after inoculation and decline from the third months onward. Significant differences were observed between the control and R. lignosus treatment in all the parameters evaluated. PMID:25601145

Ogbebor, Nicholas Obehi; Adekunle, Adefunke Temitayo; Eghafona, Odeh Nosakhare; Ogboghodo, Abraham Ikponmwosa

2015-01-01

121

Metabolic routes affecting rubber biosynthesis in Hevea brasiliensis latex.  

PubMed

The cytosolic mevalonate (MVA) pathway in Hevea brasiliensis latex is the conventionally accepted pathway which provides isopentenyl diphosphate (IPP) for cis-polyisoprene (rubber) biosynthesis. However, the plastidic 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway may be an alternative source of IPP since its more recent discovery in plants. Quantitative RT-PCR (qRT-PCR) expression profiles of genes from both pathways in latex showed that subcellular compartmentalization of IPP for cis-polyisoprene synthesis is related to the degree of plastidic carotenoid synthesis. From this, the occurrence of two schemes of IPP partitioning and utilization within one species is proposed whereby the supply of IPP for cis-polyisoprene from the MEP pathway is related to carotenoid production in latex. Subsequently, a set of latex unique gene transcripts was sequenced and assembled and they were then mapped to IPP-requiring pathways. Up to eight such pathways, including cis-polyisoprene biosynthesis, were identified. Our findings on pre- and post-IPP metabolic routes form an important aspect of a pathway knowledge-driven approach to enhancing cis-polyisoprene biosynthesis in transgenic rubber trees. PMID:22162870

Chow, Keng-See; Mat-Isa, Mohd-Noor; Bahari, Azlina; Ghazali, Ahmad-Kamal; Alias, Halimah; Mohd-Zainuddin, Zainorlina; Hoh, Chee-Choong; Wan, Kiew-Lian

2012-03-01

122

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

PubMed

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, Tainá M; Garcia, Gizele D; Carvalho, Lucas S; Lima, Alinne; Kruger, Ricardo; Pereira, Renato C; Berlinck, Roberto G S; Valle, Rogério A B; Thompson, Cristiane C; Thompson, Fabiano

2014-01-01

123

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. A yeast strain engineered to metabolize arabinose through a novel pathway is also disclosed. Methods of producing ethanol include utilizing these modified yeast strains.

Zhang, Min; Singh, Arjun; Suominen, Pirkko; Knoshaug, Eric; Franden, Mary Ann; Jarvis, Eric

2013-02-12

124

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. A yeast strain engineered to metabolize arabinose through a novel pathway is also disclosed. Methods of producing ethanol include utilizing these modified yeast strains.

Zhang, Min; Singh, Arjun; Suominen, Pirkko; Knoshaug, Eric; Franden, Mary Ann; Jarvis, Eric

2014-09-23

125

Vaginal Yeast Infections  

MedlinePLUS

... rash on the penis if they have unprotected sex with an infected woman. If this happens to your partner, he should see a doctor. Men who haven’t been circumcised are at higher risk. Lesbians may be at risk for spreading yeast infections ...

126

Yeast DNA Extraction  

NSDL National Science Digital Library

This laboratory exercise is designed to show learners how DNA can easily be extracted from yeast using simple materials. Use this experiment to supplement any unit on genetics and to demonstrate how scientists study DNA. Adult supervision is recommended. This resource guide includes tips and suggestions for instructors as well as other DNA extraction experiments and a chart for learners to answer questions.

Lana Hays

2009-01-01

127

Microencapsulation in yeast cells.  

PubMed

A method for encapsulating high concentrations of essential oils into bakers' yeast (Saccharomyces cerevisiae) is described. The process involves mixing an aqueous suspension of yeast and an essential oil, which allows the oil to pass freely through the cell wall and membrane and remain passively within the cell. Oil droplets sequestered within the cell were clearly visible using confocal microscopy. Transmission electron microscopy demonstrated that the cell wall and membrane remain intact during the process. Cells quickly lost viability during the process and it appeared unnecessary for the cells to be viable for the process to occur. Encapsulated oil was recovered from the cells using a water/ethanol extraction procedure and analysed by gas chromatography. No significant differences were noted between encapsulated and unencapsulated oil profiles. The rate of permeation of oil into the yeast cells was found to increase significantly at higher temperatures due to the phase transition of the lipid membrane. The rates at which different essential oils permeated the cell varied considerably due to variations in terpene chemistry. The encapsulation of straight chain hydrocarbons highlighted the effects of molecular size, shape and the presence of hydroxl groups on the process. The process occurs by passive diffusion as a result of hydrophobic flavour components partitioning into the cell membrane and intracellular lipid. This paper briefly reviews the patented literature and reports some of the initial observations of the transport mechanisms involved during the accumulation of essential oils by yeast cells. PMID:9818954

Bishop, J R; Nelson, G; Lamb, J

1998-01-01

128

Molecular characterization of a novel 14-3-3 protein gene (Hb14-3-3c) from Hevea brasiliensis.  

PubMed

The cDNA encoding a 14-3-3 protein, designated as Hb14-3-3c, was isolated from Hevea brasiliensis. Hb14-3-3c was 1,269 bp long containing a 795 bp open reading frame encoding a putative protein of 264 amino acids, flanked by a 146 bp 5'UTR and a 328 bp 3' UTR. The predicted molecular mass of Hb14-3-3c is 29.67 kDa, with an isoelectric point of 4.52 and the deduced protein showed high similarity to the 14-3-3 protein from other plant species. Expression analysis revealed more significant accumulation of Hb14-3-3c transcripts in latex than in leaves, buds and flowers. The transcription of Hb14-3-3c in latex was induced by jasmonate and ethephon. Overproduction of recombinant Hb14-3-3c protein gave the Escherichia coli cells more tolerance on Co(2+), Cu(2+) and Zn(2+). Through yeast two-hybrid screening, 11 interaction partners of the Hb14-3-3c, which are involved in rubber biosynthesis, stress-related responses, defence etc., were identified in rubber tree latex. Taking these data together, it is proposed that the Hb14-3-3c may participate in regulation of rubber biosynthesis. Thus, the results of this study provide novel insights into the 14-3-3 signaling related to rubber biosynthesis, stress-related responses in rubber tree. PMID:21947841

Yang, Zi-Ping; Li, Hui-Liang; Guo, Dong; Tian, Wei-Min; Peng, Shi-Qing

2012-04-01

129

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.

130

Mammalian Homology to Yeast  

NSDL National Science Digital Library

This site allows researchers to retrieve a yeast-against-mammal Basic Local Alignment Search Tool (BLAST) report by entering a gene or ORF name into a search function. The supporting data were first summarized in a recent Science article which is provided via a link to the journal (Science, 22 July 1997; Issue 277: p.1259). Steve Chervitz of Stanford University maintains this site.

1997-01-01

131

Genetic variability in the Red-tailed Amazon (Amazona brasiliensis, Psittaciformes) assessed by DNA fingerprinting  

Microsoft Academic Search

The Red-tailed Amazon (Amazona brasiliensis) is a threatened parrot endemic to the Atlantic Forest in the narrow coastal plain of south- eastern Brazil. In the present study, we used multilocus DNA fingerprinting to assess the genetic variability both within and between two red-tailed amazon groups from different localities: 15 birds from Ilha Comprida (southeastern São Paulo State) and six birds

Renato Caparroz; Paulo Martuscelli; Pedro Scherer-Neto; Cristina Yumi Miyaki; Anita Wajntal

132

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

133

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

134

Black thread disease, control measures and yield stimulation in Hevea brasiliensis in Liberia  

Microsoft Academic Search

Described are investigations, carried out in 1963 to 1971 in Hevea brasiliensis at the Firestone Plantation at Harbel in Liberia. Studied was the tapping panel disease, black thread, caused by the fungus Phytophthora palmivora. The emphasis of the investigations was on control of the disease with the fungicide captafol (Difolatan). Another line of investigation was yield stimulation with 2,4-D (salts

J. Schreurs

1972-01-01

135

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

136

Chromatographic Fractionation of Aggregation and Sex Pheromones of Nippostrongy/us brasiliensis (Nematoda)  

E-print Network

as an attractant pheromone for Pelodera strongyloides, but recognized the possibility of additional phero- mone of Aspicularis tetraptera was more heat labile than the male-producedsex phero- mone. Roberts and Thorson ('77 preliminary efforts in chemical research on the various phero- mone systems of Nippostrongylus brasiliensis

Hammock, Bruce D.

137

Geographic patterns of chromosomal variation in South American marsh rats, Holochilus brasiliensis and H. vulpinus.  

PubMed

Karyotypes were prepared from 146 individuals, representing nine populations evenly spaced along a 2,000-km north-south transect in Paraguay and Argentina, to determine the nature, extent, and pattern of chromosomal variation in Holochilus brasiliensis chacarius and H. vulpinus. Two distinct patterns of chromosomal variation characterized these two species. In H. brasiliensis, the diploid number (2n) ranged from 48 to 56 and the nombre fondamental (NF) from 57 to 63. Four classes of chromosomal variation were found in populations of H. brasiliensis: whole-arm Robertsonian (Rb) translocations, including Rb changes with monobrachial homology, variation in the number and kind of supernumerary (B) chromosomes, centromeric rearrangements (putative pericentric inversions), and variation in the amount of euchromatin. The amount of structural variation was uniformly high in all populations of H. brasiliensis sampled, and all rearrangements appeared to be in Hardy-Weinberg proportions, corroborating the hypothesis that chromosomal rearrangements are not strongly underdominant in this species. In H. vulpinus, 2n ranged from 35 to 39 and NF from 57 to 61. Two classes of variation were found in this species: variation in the number, but not the kind, of supernumerary chromosomes and variation in the amount of euchromatin. PMID:1505226

Nachman, M W

1992-01-01

138

Influence of atmospheric gases, particularly ethylene, on somatic embryogenesis of Hevea brasiliensis  

Microsoft Academic Search

The atmosphere of the culture vessel is an important factor for successful somatic embryogenesis in Hevea brasiliensis (Müll. Arg.). Considerable release of carbon dioxide and ethylene occurred during the development of calli. By avoiding the accumulation of gas, unconfined conditions were the most favourable for inducing somatic embryogenesis. Trapping of ethylene was as favourable for calli development and for somatic

Erik Auboiron; Marc-Philippe Carron; Nicole Michaux-Ferrière

1990-01-01

139

Etude morphogntique de la couronne de clones d'Hevea brasiliensis  

E-print Network

Etude morphogénétique de la couronne de clones d'Hevea brasiliensis résistant et sensible à la à la casse au vent chez Hevea lmvsiliensi.s : étude morpho- génétique de la couronne et modèle de

Paris-Sud XI, Université de

140

Hevein: an antifungal protein from rubber-tree ( Hevea brasiliensis ) latex  

Microsoft Academic Search

Several chitin-binding proteins were isolated from the “bottom fraction” of Hevea brasiliensis (Müll.) Arg. latex. One of these chitin-binding proteins is hevein, a small monomeric protein which strongly resembles the lectin from stinging nettle (Urtica dioica L.). Like the latter, hevein showed strong antifungal activity against several fungi in vitro. The possible involvement of this protein in the defense against

Jan Van Parijs; Willem F. Broekaert; Irwin J. Goldstein; Willy J. Peumans

1991-01-01

141

Effects of abscisic acid and high concentrations of PEG on Hevea brasiliensis somatic embryos development  

Microsoft Academic Search

The effects of polyethylene glycol (PEG) and abscisic acid (ABA) were analysed on Hevea brasiliensis somatic embryos development. The presence of osmoticum greatly reduced the phenomenon of secondary embryogenesis and improved the conversion of proembryonic masses (PEMs) into torpedo-shaped embryos, while the addition of exogenous ABA favoured only the formation of globular-stage embryos. The development of embryos with a desirable

Laurent Linossier; Philippe Veisseire; Françoise Cailloux; Alain Coudret

1997-01-01

142

Influence of soil, plant and meteorological factors on water relations and yield in Hevea brasiliensis  

Microsoft Academic Search

Influence of factors governing the soil-plantatmosphere system on components of water relations and yield was studied in two clones of rubber tree,Hevea brasiliensis, viz. RRII 105 and RRII 118. Clonal variations were evident in yield and yield components and associated physiological parameters in response to soil moisture status and meteorological factors. Observations made during different seasons indicatedvariations in yield are

G. Gururaja Rao; P. Sanjeeva Rao; R. Rajagopal; A. S. Devakumar; K. R. Vijayakumar; M. R. Sethuraj

1990-01-01

143

Insights into rubber biosynthesis from transcriptome analysis of Hevea brasiliensis latex  

Microsoft Academic Search

Hevea brasiliensis is the most widely cultivated spe- cies for commercial production of natural rubber (cis-polyisoprene). In this study, 10 040 expressed sequence tags (ESTs) were generated from the latex of the rubber tree, which represents the cytoplasmic content of a single cell type, in order to analyse the latex transcription profile with emphasis on rubber biosynthesis-related genes. A total

Keng-See Chow; Kiew-Lian Wan; Mohd. N. M. Isa; Azlina Bahari; Siang-Hee Tan; K. Harikrishna; Hoong-Yeet Yeang

2007-01-01

144

Yeast Colony Embedding Method  

PubMed Central

Patterning of different cell types in embryos is a key mechanism in metazoan development. Communities of microorganisms, such as colonies and biofilms also display patterns of cell types. For example, in the yeast S. cerevisiae, sporulated cells and pseudohyphal cells are not uniformly distributed in colonies. The functional importance of patterning and the molecular mechanisms that underlie these patterns are still poorly understood. One challenge with respect to investigating patterns of cell types in fungal colonies is that unlike metazoan tissue, cells in colonies are relatively weakly attached to one another. In particular, fungal colonies do not contain the same extensive level of extracellular matrix found in most tissues . Here we report on a method for embedding and sectioning yeast colonies that reveals the interior patterns of cell types in these colonies. The method can be used to prepare thick sections (0.5 ?) useful for light microscopy and thin sections (0.1 ?) suitable for transmission electron microscopy. Asci and pseudohyphal cells can easily be distinguished from ovoid yeast cells by light microscopy , while the interior structure of these cells can be visualized by EM. The method is based on surrounding colonies with agar, infiltrating them with Spurr's medium, and then sectioning. Colonies with a diameter in the range of 1-2 mm are suitable for this protocol. In addition to visualizing the interior of colonies, the method allows visualization of the region of the colony that invades the underlying agar. PMID:21445054

Piccirillo, Sarah; Honigberg, Saul M.

2011-01-01

145

Genome evolution in yeasts.  

PubMed

Identifying the mechanisms of eukaryotic genome evolution by comparative genomics is often complicated by the multiplicity of events that have taken place throughout the history of individual lineages, leaving only distorted and superimposed traces in the genome of each living organism. The hemiascomycete yeasts, with their compact genomes, similar lifestyle and distinct sexual and physiological properties, provide a unique opportunity to explore such mechanisms. We present here the complete, assembled genome sequences of four yeast species, selected to represent a broad evolutionary range within a single eukaryotic phylum, that after analysis proved to be molecularly as diverse as the entire phylum of chordates. A total of approximately 24,200 novel genes were identified, the translation products of which were classified together with Saccharomyces cerevisiae proteins into about 4,700 families, forming the basis for interspecific comparisons. Analysis of chromosome maps and genome redundancies reveal that the different yeast lineages have evolved through a marked interplay between several distinct molecular mechanisms, including tandem gene repeat formation, segmental duplication, a massive genome duplication and extensive gene loss. PMID:15229592

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

2004-07-01

146

Tapping into yeast diversity.  

PubMed

Domesticated organisms demonstrate our capacity to influence wild species but also provide us with the opportunity to understand rapid evolution in the context of substantially altered environments and novel selective pressures. Recent advances in genetics and genomics have brought unprecedented insights into the domestication of many organisms and have opened new avenues for further improvements to be made. Yet, our ability to engineer biological systems is not without limits; genetic manipulation is often quite difficult. The budding yeast, Saccharomyces cerevisiae, is not only one of the most powerful model organisms, but is also the premier producer of fermented foods and beverages around the globe. As a model system, it entertains a hefty workforce dedicated to deciphering its genome and the function it encodes at a rich mechanistic level. As a producer, it is used to make leavened bread, and dozens of different alcoholic beverages, such as beer and wine. Yet, applying the awesome power of yeast genetics to understanding its origins and evolution requires some knowledge of its wild ancestors and the environments from which they were derived. A number of surprisingly diverse lineages of S. cerevisiae from both primeval and secondary forests in China have been discovered by Wang and his colleagues. These lineages substantially expand our knowledge of wild yeast diversity and will be a boon to elucidating the ecology, evolution and domestication of this academic and industrial workhorse. PMID:23281494

Fay, Justin C

2012-11-01

147

Epidemiology of Ornithodoros brasiliensis (mouro tick) in the southern Brazilian highlands and the description of human and animal retrospective cases of tick parasitism.  

PubMed

Ornithodoros brasiliensis, also known as the "mouro" tick, is an argasid tick found exclusively in the southern Brazilian highlands. O. brasiliensis parasitism is frequently associated with severe symptoms directly induced by the tick bite, a condition compatible with the definition of tick toxicosis. The objectives of this work include (i) the determination of the distribution of O. brasiliensis in farms located in the tick-endemic region, (ii) the description of the characteristics of O. brasiliensis habitats, (iii) the analysis of risk factors associated with O. brasiliensis, and (iv) the retrospective description of cases of human and animal parasitism by O. brasiliensis. Of the 30 farms included in this study, O. brasiliensis was identified on 5 farms (frequency 16.7%), in which several ticks found in high density buried in soil were collected. Information regarding the tick habitats and the local population was recorded. The data indicated that O. brasiliensis feeds on humans, dogs, armadillos (Dasypus hybridus), and possibly skunks (Conepatus chinga). The analysis of risk factors indicated that the presence of house basements with an unpaved (natural soil) floor on farms and insufficient sanitary conditions significantly enhanced the probability of identifying O. brasiliensis. Additionally, we describe retrospectively cases of tick parasitism in 28 humans and 11 dogs including the most common symptoms associated with tick toxicosis. This is the first study concerning O. brasiliensis epidemiology, distribution, and habitat, and the report represents the most comprehensive characterization of Ornithodoros bite-associated toxicosis syndrome. PMID:23238249

Reck, José; Marks, Fernanda S; Guimarães, Jorge A; Termignoni, Carlos; Martins, João Ricardo

2013-02-01

148

Synthesis and in vitro anthelmintic activity against Nippostrongylus brasiliensis of new 2-amino-4-hydroxy-delta-valerolactam derivatives.  

PubMed

The synthesis of a series of 2-amino-4-hydroxy-delta-valerolactam derivatives is described (compounds 4 to 10). These compounds showed a high anthelmintic in vitro activity against the Nippostrongylus brasiliensis model. PMID:9580122

Gordon, S; Costa, L; Incerti, M; Manta, E; Saldaña, J; Domínguez, L; Mariezcurrena, R; Suescun, L

1997-10-01

149

Development and characterization of microsatellite markers for the medicinal plant Smilax brasiliensis (Smilacaceae) and related species1  

PubMed Central

• Premise of the study: A new set of microsatellite or simple sequence repeat (SSR) markers were developed for Smilax brasiliensis, which is popularly known as sarsaparilla and used in folk medicine as a tonic, antirheumatic, and antisyphilitic. Smilax brasiliensis is sold in Brazilian pharmacies, and its origin and effectiveness are not subject to quality control. • Methods and Results: Using a protocol for genomic library enrichment, primer pairs were developed for 26 microsatellite loci and validated in 17 accessions of S. brasiliensis. Thirteen loci were polymorphic and four were monomorphic. The primers successfully amplified alleles in the congeners S. campestris, S. cissoides, S. fluminensis, S. goyazana, S. polyantha, S. quinquenervia, S. rufescens, S. subsessiliflora, and S. syphilitica. • Conclusions: The new SSR markers described herein are informative tools for genetic diversity and gene flow studies in S. brasiliensis and several congeners. PMID:25202555

Martins, Aline R.; Abreu, Aluana G.; Bajay, Miklos M.; Villela, Priscilla M. S.; Batista, Carlos E. A.; Monteiro, Mariza; Alves-Pereira, Alessandro; Figueira, Glyn M.; Pinheiro, José B.; Appezzato-da-Glória, Beatriz; Zucchi, Maria I.

2013-01-01

150

Interleukin5 Transgenic Mice Show Enhanced Resistance to Primary Infections with Nippostrongylus brasiliensis but Not Primary Infections with Toxocara canis  

Microsoft Academic Search

In this study, interleukin-5 (IL-5) transgenic mice with lifelong eosinophilia were assessed for resistance to primary infections with two tissue-invading nematodes, Nippostrongylus brasiliensis and Toxocara canis. Relative to nontransgenic littermates, three lines of IL-5 transgenic mice with varying degrees of eosinophilia all dis- played enhanced resistance to N. brasiliensis. Although the timing of final worm expulsion was similar in trans-

LINDSAY A. DENT; CHRISTINE M. DALY; GRAHAM MAYRHOFER; TRUDY ZIMMERMAN; ANN HALLETT; LEON P. BIGNOLD; JENETTE CREANEY; JIM C. PARSONS

1999-01-01

151

Characterization of cDNA and genomic clones encoding 3-hydroxy-3-methylglutaryl-coenzyme A reductase from Hevea brasiliensis  

Microsoft Academic Search

Hevea brasiliensis is the major producer of natural rubber which is cis-1,4-polyisoprene. The enzyme 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR) is involved in the biosynthesis of rubber and other plant products. We have used a hamster HMGR cDNA clone as a heterologous hybridization probe to isolate and characterize cDNA and genomic clones of HMGR from H. brasiliensis. Sequence analysis revealed that these

Mee-Len Chye; Anil Kush; Chio-Tee Tan; Nam-Hai Chua

1991-01-01

152

Production of Food Grade Yeasts  

Microsoft Academic Search

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

Argyro Bekatorou; Costas Psarianos; Athanasios A. Koutinas

2006-01-01

153

Red yeast rice for dysipidemia.  

PubMed

Red yeast rice is an ancient Chinese food product that contains monacolins, chemical substances that are similar to statins in their mechanisms of action and lipid lowering properties. Several studies have found red yeast rice to be moderately effective at improving the lipid profile, particularly for lowering the low-density lipoprotein cholesterol levels. One large randomized controlled study from China found that red yeast rice significantly improved risk of major adverse cardiovascular events and overall survival in patients following myocardial infarction. Thus, red yeast rice is a potentially useful over-the-counter cholesterol-lowering agent. However, many red yeast rice formulations are non-standardized and unregulated food supplements, and there is a need for further research and regulation of production. PMID:24003656

Shamim, Shariq; Al Badarin, Firas J; DiNicolantonio, James J; Lavie, Carl J; O'Keefe, James H

2013-01-01

154

A common Caatinga cactus, Pilosocereus gounellei, is an important ecotope of wild Triatoma brasiliensis populations in the Jaguaribe valley of northeastern Brazil.  

PubMed

Triatoma brasiliensis is the most important vector of Chagas disease in the Caatinga eco-region of northeastern Brazil. Wild T. brasiliensis populations have been reported only from rocky outcrops. However, this species frequently infests/re-infests houses in rock-free sedimentary lowlands. We therefore hypothesized that it should also occupy other natural ecotopes. We show that a common Caatinga cactus, Pilosocereus gounellei, locally known as xiquexique, often harbors T. brasiliensis breeding colonies apparently associated with rodents (n = 44 cacti, infestation rate = 47.7%, 157 bugs captured). Our findings suggest that infested cacti might be involved in house re-infestation by T. brasiliensis in the Caatinga region. PMID:24710611

Valença-Barbosa, Carolina; Lima, Marli M; Sarquis, Otília; Bezerra, Claudia M; Abad-Franch, Fernando

2014-06-01

155

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

156

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

157

Yeasts from the leaves of pasture plants  

Microsoft Academic Search

The yeast population upon the leaves of pasture plants in New Zealand has been investigated in relation to season, soil yeast flora, and incidence of facial eczema toxin in autumn pasture. Leaf yeasts were shown to be taxonomically distinct from soil yeasts and to vary with season but not to vary with the localities sampled. During most of the year

M. E. di Menna

1959-01-01

158

Yeasts: From genetics to biotechnology  

SciTech Connect

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

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

1995-12-31

159

Interaction Between Yeasts and Zinc  

NASA Astrophysics Data System (ADS)

Zinc is an essential trace element in biological systems. For example, it acts as a cellular membrane stabiliser, plays a critical role in gene expression and genome modification and activates nearly 300 enzymes, including alcohol dehydrogenase. The present chapter will be focused on the influence of zinc on cell physiology of industrial yeast strains of Saccharomyces cerevisiae, with special regard to the uptake and subsequent utilisation of this metal. Zinc uptake by yeast is metabolism-dependent, with most of the available zinc translocated very quickly into the vacuole. At cell division, zinc is distributed from mother to daughter cells and this effectively lowers the individual cellular zinc concentration, which may become zinc depleted at the onset of the fermentation. Zinc influences yeast fermentative performance and examples will be provided relating to brewing and wine fermentations. Industrial yeasts are subjected to several stresses that may impair fermentation performance. Such stresses may also impact on yeast cell zinc homeostasis. This chapter will discuss the practical implications for the correct management of zinc bioavailability for yeast-based biotechnologies aimed at improving yeast growth, viability, fermentation performance and resistance to environmental stresses

Nicola, Raffaele De; Walker, Graeme

160

Lager yeast comes of age.  

PubMed

Alcoholic fermentations have accompanied human civilizations throughout our history. Lager yeasts have a several-century-long tradition of providing fresh beer with clean taste. The yeast strains used for lager beer fermentation have long been recognized as hybrids between two Saccharomyces species. We summarize the initial findings on this hybrid nature, the genomics/transcriptomics of lager yeasts, and established targets of strain improvements. Next-generation sequencing has provided fast access to yeast genomes. Its use in population genomics has uncovered many more hybridization events within Saccharomyces species, so that lager yeast hybrids are no longer the exception from the rule. These findings have led us to propose network evolution within Saccharomyces species. This "web of life" recognizes the ability of closely related species to exchange DNA and thus drain from a combined gene pool rather than be limited to a gene pool restricted by speciation. Within the domesticated lager yeasts, two groups, the Saaz and Frohberg groups, can be distinguished based on fermentation characteristics. Recent evidence suggests that these groups share an evolutionary history. We thus propose to refer to the Saaz group as Saccharomyces carlsbergensis and to the Frohberg group as Saccharomyces pastorianus based on their distinct genomes. New insight into the hybrid nature of lager yeast will provide novel directions for future strain improvement. PMID:25084862

Wendland, Jürgen

2014-10-01

161

Improvement of somatic embryogenesis in Hevea brasiliensis (Müll. Arg.) using the temporary immersion technique  

Microsoft Academic Search

Summary  A culture procedure using temporary immersion in a liquid medium was tested for somatic embryogenesis of Hevea brasiliensis (Mll. Arg.). Embryogenic callus was placed under regeneration conditions, either on a gelled medium (Phytagel, Sigma, St.\\u000a Louis, MO) or in a container designed for temporary immersion. The latter technique has some advantages over the use of a\\u000a gelled medium during both

H. Etienne; M. Lartaud; N. Michaux-Ferriére; M. P. Carron; M. Berthouly; C. Teisson

1997-01-01

162

A note on the infection of Scomberomorus brasiliensis (Osteichthyes, Scombridae) by Kudoa sp. (Myxozoa: Multivalvulida).  

PubMed

The infection of Scomberomorus brasiliensis by the myxozoan Kudoa sp. is reported. The parasites formed plasmodiae inside the skeletal muscle fibres. The spores were quadrate in apical view and bell-like shaped in lateral view, containing four equally sized more or less rounded polar capsules. No detrimental effects were observed in the host, namely muscle liquefaction. The importance of these parasites is discussed. PMID:25627380

Eiras, Jc; Lima, Jtax; Cruz, Cf; Saraiva, A

2014-08-01

163

Dietary energetics of the insectivorous Mexican free-tailed bat ( Tadarida brasiliensis ) during pregnancy and lactation  

Microsoft Academic Search

Stomach content analysis of 20 pregnant (x body mass=13.4 g) and 18 lactating (x body mass=11.5 g) female Tadarida brasiliensis revealed that the diet, expressed as percent volume, consists largely of lepidopterans, coleopterans, hymenopterans, and dipterans, in decreasing order of importance. We found no significant difference in the diet of pregnant and lactating females when expressed as percent volume. However,

T. H. Kunz; J. O. Whitaker Jr; M. D. Wadanoli

1995-01-01

164

Feline sporotrichosis due to Sporothrix brasiliensis : an emerging animal infection in São Paulo, Brazil.  

PubMed

BackgroundSporotrichosis is a mycotic infectious disease that is generally acquired by traumatic inoculation of contaminated materials especially from plant debris or through bites and scratches from diseased animals, such as domestic cats. It affects the skin, lymphatic system, and other organs in the warm-blooded host. Etiological agents are embedded in the plant-associated order Ophiostomatales. With essential differences between possible outbreak sources and ecological niche, host-environment interactions are classic determinants of risk factors for disease acquisition. Sporotrichosis outbreaks with zoonotic transmission, such as those that are ongoing in southern and southeastern Brazil, have highlighted the threat of cross-species pathogen transmission. Sporothrix brasiliensis has emerged as a human threat owing to the intimate contact pattern between diseased cats and humans in endemic areas.ResultsWe describe the recent emergence of feline sporotrichosis in the metropolitan region of São Paulo, Brazil, with an overwhelming occurrence of S. brasiliensis as the etiological agent. A phylogenetic and a haplotype approach were used to investigate the origin of this epidemic and the impact of feline transmission on genetic diversity. During the last 3-year period, 163 cases of feline sporotrichosis were reported in São Paulo with proven S. brasiliensis culture. The haplotype diversity of feline S. brasiliensis isolates revealed the expansion of a clonal population with low genetic diversity. Haplotype analysis confirmed that isolates from São Paulo shared the haplotype originated in the long-lasting outbreak of cat-transmitted sporotrichosis in Rio de Janeiro, which differed from the haplotype circulating in the Rio Grande do Sul epidemic.ConclusionsThe fast spread of sporotrichosis in a short period of time highlights the potential for outbreaks and suggests that the mycosis may affect an urban population with a high concentration of susceptible felines. The feline sporotrichosis epidemic shows no signs of slowing, and this epidemiological pattern may require specific public health strategies to control future outbreaks. PMID:25407096

Montenegro, Hildebrando; Rodrigues, Anderson; Dias, Maria; da Silva, Elisabete; Bernardi, Fernanda; de Camargo, Zoilo

2014-11-19

165

Holochilus brasiliensis and Nectomys squamipes (Rodentia-Cricetidae) natural hosts of Schistosoma mansoni.  

PubMed

After several Brazilian researchers, the author examines the capacity of two species of rodents Cricetidae, Holochilus brasiliensis and Nectomys squamipes, to maintain the biological cycle of Schistosoma mansoni in the field and to be parasite reservoir: (a) the role they are able to play in human endemy; (b) the methods necessary to characterize the population of Schistosoma mansoni related either to man, either to rodents, either to both. PMID:1343905

Picot, H

1992-01-01

166

Breeding of wild-caught rodent cricetidae Holochilus brasiliensis under laboratory conditions.  

PubMed

The breeding of wild-caught rodent Holochilus brasiliensis (Desmarest, 1819) was studied under laboratory conditions. The mean gestation length was 28.4 days. Litter size ranged from one to five. Males matured at 2-3 months and females at 2-4.5 months of age. The oestrous cycle lasted 6-8 days. Eleven pairs observed over 6-13 months increased to a population of 276 individuals (153 males and 123 females). PMID:3540447

Mello, D A

1986-07-01

167

Molecular cloning, characterization and expression of Mn-superoxide dismutase from the rubber tree (Hevea brasiliensis)  

Microsoft Academic Search

A genomic clone encoding manganese-containing superoxide dismutase (SOD; EC 1.15.1.1) was isolated from a Hevea brasiliensis genomic library made in ? phage EMBL3 by using a heterologous cDNA probe of MnSOD from Nicotiana plumbaginifolia. The nucleotide sequence of 4968 bp from the genomic clone was determined. Based on the putative translation initiation codon and stop codon, PCR primers were designed

Zhonghe Miao; John J. Gaynor

1993-01-01

168

Long-term somatic embryogenesis and maturation of somatic embryos in Hevea brasiliensis  

Microsoft Academic Search

A high frequency of secondary embryogenesis was induced from isolated early cotyledonary-stage somatic embryos of Hevea brasiliensis. A long-term embryogenic line was established by the use of recurrent embryogenesis and maintained for 3 years on hormone-free medium by the transfer of selected proembryogenic masses every 10 days.The addition of 234 mM sucrose as stress with sucrose and 10?5 M abscisic

Françoise Cailloux; Josiane Julien-Guerrier; Laurent Linossier; Alain Coudret

1996-01-01

169

Adsorption studies of basic dye on activated carbon derived from agricultural waste: Hevea brasiliensis seed coat  

Microsoft Academic Search

Activated carbon prepared from rubber (Hevea brasiliensis) seed coat was used to remove basic blue 3 (BB3) from aqueous solutions. Batch adsorption studies were conducted to evaluate the effect of contact time, and initial concentration (50–500mg\\/L) on the removal of BB3 at temperature of 30°C. The equilibrium adsorption data of BB3 on activated carbon were analyzed by the Langmuir, Freundlich

B. H. Hameed; F. B. M. Daud

2008-01-01

170

Production of biodiesel using rubber [ Hevea brasiliensis (Kunth. Muell.)] seed oil  

Microsoft Academic Search

Rubber (Hevea brasiliensis) seed oil was extracted, and its physical and chemical characteristics determined. The crude oil was bleached and the ester-fuel (methyl-ester) was prepared by trans-esterification with 6-molar excess of methanol using sodium hydroxide as a catalyst. Methyl ester yield and fuel properties of the oil (crude and bleached) and its methyl ester were determined and compared to that

O. E. Ikwuagwu; I. C. Ononogbu; O. U. Njoku

2000-01-01

171

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

172

Adsorption of copper on rubber ( Hevea brasiliensis) leaf powder: Kinetic, equilibrium and thermodynamic studies  

Microsoft Academic Search

The adsorption of Cu(II) ions from aqueous solution by rubber (Hevea brasiliensis) leaf powder (RHBL) was studied in a batch adsorption system. Characteristics of RHBL such as pH of aqueous slurry, pH of zero point charge (pHZPC), surface area and pore diameter, Fourier transform infrared (FTIR), scanning electron microscopy (SEM) and electron dispersive spectroscopy (EDS) were investigated. Factors influencing adsorption

W. S. Wan Ngah; M. A. K. M. Hanafiah

2008-01-01

173

Genetic diversity among wild and cultivated populations of Hevea brasiliensis assessed by nuclear RFLP analysis  

Microsoft Academic Search

Restriction fragment length polymorphism was assessed in wild and cultivated populations of Hevea brasiliensis using random probes from an Hevea nuclear library. One-hundred-and-sixty-four individuals were surveyed, and the results discussed in the light of previous work performed on isozyme variation. Both studies show that germplasm collections have led to an effective enrichment of the genetic resources available for Hevea breeding,

P. Besse; M. Seguin; P. Lebrun; M. H. Chevallier; D. Nicolas; C. Lanaud

1994-01-01

174

Crystallization of Hevamine, an Enzyme with Lysozyme\\/Chitinase Activity from Hevea brasiliensis Latex  

Microsoft Academic Search

Hevamine, an enzyme with both lysozyme and chitinase activity, was isolated and purified from Hevea brasiliensis (rubber tree) latex. The enzyme (molecular weight 29,000) is homologous to certain “pathogenesis-related” proteins from plants, but not to hen egg-white or phage T4 lysozyme. To investigate the atomic details of the substrate specificity and the cause for hevamine’s low pH optimum (pH 4.0),

Bauke W. Dijkstra; Jaap J. Beintema; Asmini Budiani; Henriëtte J. Rozeboom

1990-01-01

175

Effect of abscisic acid and cytokinins on the development of somatic embryos in Hevea brasiliensis  

Microsoft Academic Search

Addition of liquid medium, conditioned by an embryogenic suspension, to MH1 solid medium (3,4-dichlorophenoxyacetic acid 9 µM, 6-benzyladenine 9 µM) permitted the frequent induction of highly embryogenic calli from slices of internal integument of immature seeds of Hevea brasiliensis Müll. Arg. The proliferation of embryogenic cell clusters was achieved in MH1 liquid medium. Abscisic acid (ABA), cytokinins and adenine were

P. Veisseire; L. Linossier; A. Coudret

1994-01-01

176

Marine yeast isolation and industrial application.  

PubMed

Over the last century, terrestrial yeasts have been widely used in various industries, such as baking, brewing, wine, bioethanol and pharmaceutical protein production. However, only little attention has been given to marine yeasts. Recent research showed that marine yeasts have several unique and promising features over the terrestrial yeasts, for example higher osmosis tolerance, higher special chemical productivity and production of industrial enzymes. These indicate that marine yeasts have great potential to be applied in various industries. This review gathers the most recent techniques used for marine yeast isolation as well as the latest applications of marine yeast in bioethanol, pharmaceutical and enzyme production fields. PMID:24738708

Zaky, Abdelrahman Saleh; Tucker, Gregory A; Daw, Zakaria Yehia; Du, Chenyu

2014-09-01

177

Marine yeast isolation and industrial application  

PubMed Central

Over the last century, terrestrial yeasts have been widely used in various industries, such as baking, brewing, wine, bioethanol and pharmaceutical protein production. However, only little attention has been given to marine yeasts. Recent research showed that marine yeasts have several unique and promising features over the terrestrial yeasts, for example higher osmosis tolerance, higher special chemical productivity and production of industrial enzymes. These indicate that marine yeasts have great potential to be applied in various industries. This review gathers the most recent techniques used for marine yeast isolation as well as the latest applications of marine yeast in bioethanol, pharmaceutical and enzyme production fields. PMID:24738708

Zaky, Abdelrahman Saleh; Tucker, Gregory A; Daw, Zakaria Yehia; Du, Chenyu

2014-01-01

178

Medicinal yeast extracts.  

PubMed

Alcoholic extracts of bakers' yeast (Saccharomyces cerevisiae) have been used for over 60 years in over-the-counter medications for the treatment of hemorrhoids, burns, and wounds. Although previous studies suggested that small peptides were responsible for the medical observations, the peptides were never resolved into separate fractions and identified. In the present report, a protein fraction was prepared by RPC18 chromatography of the extract which enhances wound closure in both diabetic and non-diabetic littermates. The peptides are active in nanomolar amounts and are 600 times more active than the initial extract. SDS-PAGE and N-terminal amino acid sequencing identified 4 polypeptides in the extract. Three of the proteins were small molecular weight stress-associated proteins: copper, zinc superoxide-dismutase, ubiquitin, and glucose lipid regulated protein (HSP 12). The fourth protein, acyl-CoA binding protein II, has not been previously associated with stress proteins. PMID:10547066

Schlemm, D J; Crowe, M J; McNeill, R B; Stanley, A E; Keller, S J

1999-09-01

179

Yeast Breads: Made at Home.  

E-print Network

of ' oven to give crustiness. Makes 2 dozen large rolls. 1 Crusty water rolls. TOMATO CHEESE ROLLS 314 cup lukewarm tomato juice 1 package yeast or 1 .yeast cake 1 tablespoon sugar 1 teaspoon salt 3 tablespoons .melted butter or margarine 2114 CUPS... flour Add yeast and sugar to lukewarm tomato juice and Irt $tdnd until dissolved. Add salt and fat. Add half the fln~lr and beat until smooth. Add remaining flour Place in greased bowl and brush with melted fat. Cover 2nd let rise until doubled...

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

1957-01-01

180

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, José Marcos C.; Lehane, Michael J.; Gontijo, Nelder Figueiredo; Veloso, Artur Botelho; Sant'Anna, Mauricio R.V.; Araujo, Ricardo Nascimento; Grisard, Edmundo C.; Pereira, Marcos Horácio

2007-01-01

181

The Yeast Sphingolipid Signaling Landscape  

PubMed Central

Sphingolipids are recognized as signaling mediators in a growing number of pathways, and represent potential targets to address many diseases. The study of sphingolipid signaling in yeast has created a number of breakthroughs in the field, and has the potential to lead future advances. The aim of this article is to provide an inclusive view of two major frontiers in yeast sphingolipid signaling. In the first section, several key studies in the field of sphingolipidomics are consolidated to create a yeast sphingolipidome that ranks nearly all known sphingolipid species by their level in a resting yeast cell. The second section presents an overview of most known phenotypes identified for sphingolipid gene mutants, presented with the intention of illuminating not yet discovered connections outside and inside of the field. PMID:24220500

Montefusco, David J.; Matmati, Nabil

2014-01-01

182

Yeast Breads: Made at Home.  

E-print Network

/4 cup lukewarm tomato juice I 1 package or cake yeast 1 tablespoon sugar 1 teaspoon salt 3 tablespoons melted butter or margarine 21/4 CUPS flour Add penst and sugar to lukewarm tomato juice and tomato juice I 1 package or cake yeast 1 tablespoon sugar 1 teaspoon salt 3 tablespoons melted butter or margarine 21/4 CUPS flour Add penst and sugar to lukewarm tomato juice and

Reasonover, Frances

1971-01-01

183

Molecular Genetic Analysis in Yeast  

NSDL National Science Digital Library

The four exercises presented here use basic and advanced procedures of recombinant DNA technology to perform molecular genetic analysis in the yeast Saccharomyces cerevisiae. Their fulluse is intended for a senior-level molecular genetics (or similar) course; however, Experiments 1, 2, and 4 are appropriate for lower-level courses. It is expected that the instructor will have some familiarity with the concepts and terminology of recombinant DNA technology and with yeast genetics.

Daniel D. Burke (Seton Hall University; )

1989-06-06

184

Ornithodoros brasiliensis (mouro tick) salivary gland homogenates inhibit in vivo wound healing and in vitro endothelial cell proliferation.  

PubMed

Ornithodoros brasiliensis is a nidicolous tick only found in the southern Brazilian highlands region. O. brasiliensis parasitism is frequently associated with toxicosis syndrome, which can lead to severe reactions, ranging from local pruritus and pain to systemic disturbances both in humans and dogs. One of the most frequent findings associated with an O. brasiliensis bite is a slow healing lesion at the site of tick attachment, which can take several weeks to heal. This work tested the hypothesis that an O. brasiliensis salivary gland homogenate is able to modulate the skin wound-healing process in vivo, using a model of excisional skin lesion in rats, which are divided into two groups: (1) control group and (2) treated group, which topically received salivary gland homogenate equivalent to the protein amount of one whole salivary gland (?5 ?g protein). The hypothesis that O. brasiliensis salivary gland homogenates interfere with endothelial cell proliferation, a key role phenomenon in wound healing, was also tested. O. brasiliensis salivary gland homogenates significantly delay skin wound healing. The time to full healing of skin lesions in control rats was 15 days, contrasting with 24 days in rats topically treated with O. brasiliensis salivary gland homogenates. The calculated HT50 (healing time to recover 50% of the wound area) for control groups was 3.6 days (95% CI, 3.2-3.9) and for salivary gland treated rats was 7.7 days (95% CI, 7.0-8.4). Salivary gland homogenates have a strong cytotoxic activity on cultured endothelial cells (LC50, 13.6 mg/ml). Also, at sublethal concentrations (?3 mg/ml), salivary gland homogenates have a remarkable anti-proliferative activity (IC50 0.7 mg/ml) on endothelial cells, equivalent to ?0.03 salivary gland pairs, an activity which seems to be much greater than reported for any other tick species. This is the first report about the biological activities of O. brasiliensis salivary compounds and provides the first in vivo evidence to support the concept of wound-healing modulation by tick salivary secretions. Results shown here contribute to an understanding of O. brasiliensis tick toxicosis syndrome, and also increase our knowledge of tick salivary bioactive compounds. PMID:23397378

Reck, José; Marks, Fernanda S; Termignoni, Carlos; Guimarães, Jorge A; Martins, João Ricardo

2013-04-01

185

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

186

Metabolic regulation of yeast  

NASA Astrophysics Data System (ADS)

Metabolic regulation which is based on endogeneous and exogeneous process variables which may act constantly or time dependently on the living cell is discussed. The observed phenomena of the regulation are the result of physical, chemical, and biological parameters. These parameters are identified. Ethanol is accumulated as an intermediate product and the synthesis of biomass is reduced. This regulatory effect of glucose is used for the aerobic production of ethanol. Very high production rates are thereby obtained. Understanding of the regulation mechanism of the glucose effect has improved. In addition to catabolite repression, several other mechanisms of enzyme regulation have been described, that are mostly governed by exogeneous factors. Glucose also affects the control of respiration in a third class of yeasts which are unable to make use of ethanol as a substrate for growth. This is due to the lack of any anaplerotic activity. As a consequence, diauxic growth behavior is reduced to a one-stage growth with a drastically reduced cell yield. The pulse chemostat technique, a systematic approach for medium design is developed and medium supplements that are essential for metabolic control are identified.

Fiechter, A.

1982-12-01

187

Synthetic Yeast Cooperation  

NASA Astrophysics Data System (ADS)

Cooperation is wide-spread and has been postulated to drive major transitions in evolution. However, Darwinian selection favors ``cheaters'' that consume benefits without paying a fair cost. How did cooperation evolve against the threat of cheaters? To investigate the evolutionary trajectories of cooperation, we created a genetically tractable system that can be observed as it evolves from inception. The system consists of two engineered yeast strains -- a red-fluorescent strain that requires adenine and releases lysine and a yellow-fluorescent strain that requires lysine and releases adenine. Cells that consume but not supply metabolites would be cheaters. From the properties of two cooperating strains, we calculated and experimentally verified the minimal initial cell densities required for the viability of the cooperative system in the absence of exogenously added adenine and lysine. Strikingly, evolved cooperative systems were viable at 100-fold lower initial cell densities than their ancestors. We are investigating the nature and diversity of pro-cooperation changes, the dynamics of cooperator-cheater cocultures, and the effects of spatial environment on cooperation and cheating.

Shou, Wenying; Burton, Justin

2010-03-01

188

Effects of polysaccharide from fruiting bodies of Agaricus bisporus, Agaricus brasiliensis, and Phellinus linteus on alcoholic liver injury.  

PubMed

In the present study, the curative effects of crude polysaccharides (PSs) from mushrooms on the symptoms of alcoholic liver injury were investigated. PSs from Agaricus bisporus, Agaricus brasiliensis, and Phellinus linteus fruiting bodies were administered by gavage at levels of 100?mg per kg body weight per day for 7?d after the onset of the disease. The caspase-3 activity, mitochondrial membrane potential, mitochondrial outer membrane integrity of the liver tissues of sacrificed rats, and the serum alanine aminotransferase (ALT) levels were determined. In addition, light and transmission electron microscope (TEM) studies were performed for histopathological and cytological evaluations on liver sections. PSs from A. brasiliensis decreased ALT level and mitochondrial membrane potential and increased the outer membrane integrity; microscopic examinations also revealed normal hepatocytes and tissue. On the basis of our data, it can be argued that crude PSs from Agaricus brasiliensis have therapeutic potential for alcoholic liver injury. PMID:24392995

Uyanoglu, Mustafa; Canbek, Mediha; van Griensven, Leo J L D; Yamac, Mustafa; Senturk, Hakan; Kartkaya, Kaz?m; Oglakc?, Aysegul; Turgak, Ozge; Kanbak, Gungor

2014-06-01

189

Differences in Cell Morphometry, Cell Wall Topography and Gp70 Expression Correlate with the Virulence of Sporothrix brasiliensis Clinical Isolates  

PubMed Central

Sporotrichosis is a chronic infectious disease affecting both humans and animals. For many years, this subcutaneous mycosis had been attributed to a single etiological agent; however, it is now known that this taxon consists of a complex of at least four pathogenic species, including Sporothrix schenckii and Sporothrix brasiliensis. Gp70 was previously shown to be an important antigen and adhesin expressed on the fungal cell surface and may have a key role in immunomodulation and host response. The aim of this work was to study the virulence, morphometry, cell surface topology and gp70 expression of clinical isolates of S. brasiliensis compared with two reference strains of S. schenckii. Several clinical isolates related to severe human cases or associated with the Brazilian zoonotic outbreak of sporotrichosis were genotyped and clustered as S. brasiliensis. Interestingly, in a murine subcutaneous model of sporotrichosis, these isolates showed a higher virulence profile compared with S. schenckii. A single S. brasiliensis isolate from an HIV-positive patient not only showed lower virulence but also presented differences in cell morphometry, cell wall topography and abundant gp70 expression compared with the virulent isolates. In contrast, the highly virulent S. brasiliensis isolates showed reduced levels of cell wall gp70. These observations were confirmed by the topographical location of the gp70 antigen using immunoelectromicroscopy in both species. In addition, the gp70 molecule was sequenced and identified using mass spectrometry, and the sequenced peptides were aligned into predicted proteins using Blastp with the S. schenckii and S. brasiliensis genomes. PMID:24116065

Castro, Rafaela A.; Kubitschek-Barreira, Paula H.; Teixeira, Pedro A. C.; Sanches, Glenda F.; Teixeira, Marcus M.; Quintella, Leonardo P.; Almeida, Sandro R.; Costa, Rosane O.; Camargo, Zoilo P.; Felipe, Maria S. S.; de Souza, Wanderley; Lopes-Bezerra, Leila M.

2013-01-01

190

Nuclear Transport of Yeast Proteasomes  

PubMed Central

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

191

In-depth proteome analysis of the rubber particle of Hevea brasiliensis (para rubber tree).  

PubMed

The rubber particle is a special organelle in which natural rubber is synthesised and stored in the laticifers of Hevea brasiliensis. To better understand the biological functions of rubber particles and to identify the candidate rubber biosynthesis-related proteins, a comprehensive proteome analysis was performed on H. brasiliensis rubber particles using shotgun tandem mass spectrometry profiling approaches-resulting in a thorough report on the rubber particle proteins. A total of 186 rubber particle proteins were identified, with a range in relative molecular mass of 3.9-194.2 kDa and in isoelectric point values of 4.0-11.2. The rubber particle proteins were analysed for gene ontology and could be categorised into eight major groups according to their functions: including rubber biosynthesis, stress- or defence-related responses, protein processing and folding, signal transduction and cellular transport. In addition to well-known rubber biosynthesis-related proteins such as rubber elongation factor (REF), small rubber particle protein (SRPP) and cis-prenyl transferase (CPT), many proteins were firstly identified to be on the rubber particles, including cyclophilin, phospholipase D, cytochrome P450, small GTP-binding protein, clathrin, eukaryotic translation initiation factor, annexin, ABC transporter, translationally controlled tumour protein, ubiquitin-conjugating enzymes, and several homologues of REF, SRPP and CPT. A procedure of multiple reaction monitoring was established for further protein validation. This comprehensive proteome data of rubber particles would facilitate investigation into molecular mechanisms of biogenesis, self-homeostasis and rubber biosynthesis of the rubber particle, and might serve as valuable biomarkers in molecular breeding studies of H. brasiliensis and other alternative rubber-producing species. PMID:23553221

Dai, Longjun; Kang, Guijuan; Li, Yu; Nie, Zhiyi; Duan, Cuifang; Zeng, Rizhong

2013-05-01

192

Loss of Complement Activation and Leukocyte Adherence as Nippostrongylus brasiliensis Develops within the Murine Host  

PubMed Central

Complement activation and C3 deposition on the surface of parasitic helminths may be important for recruitment of leukocytes and for damage to the target organism via cell-mediated mechanisms. Inhibition of complement activation would therefore be advantageous to parasites, minimizing damage and enhancing migration through tissues. The aim of this study was to determine ex vivo if complement activation by, and leukocyte adherence to, the nematode Nippostrongylus brasiliensis change as the parasite matures and migrates through the murine host. Pathways of activation of complement and the mechanism of adherence of leukocytes were also defined using sera from mice genetically deficient in either C1q, factor B, C1q and factor B, C3, or C4. Substantive deposition of C3 and adherence of eosinophil-rich leukocytes were seen with infective-stage (L3) but not with lung-stage (L4) larvae. Adult intestinal worms had low to intermediate levels of both C3 and leukocyte binding. For L3 and adult worms, complement deposition was principally dependent on the alternative pathway. For lung-stage larvae, the small amount of C3 detected was dependent to similar degrees on both the lectin and alternative pathways. The classical pathway was not involved for any of the life stages of the parasite. These results suggest that in primary infections, the infective stage of N. brasiliensis is vulnerable to complement-dependent attack by leukocytes. However, within the first 24 h of infection, N. brasiliensis acquires the ability to largely avoid complement-dependent immune responses. PMID:16239545

Giacomin, Paul R.; Wang, Hui; Gordon, David L.; Botto, Marina; Dent, Lindsay A.

2005-01-01

193

Simulating Population Genetics of Pathogen Vectors in Changing Landscapes: Guidelines and Application with Triatoma brasiliensis  

PubMed Central

Background Understanding the mechanisms that influence the population dynamics and spatial genetic structure of the vectors of pathogens infecting humans is a central issue in tropical epidemiology. In view of the rapid changes in the features of landscape pathogen vectors live in, this issue requires new methods that consider both natural and human systems and their interactions. In this context, individual-based model (IBM) simulations represent powerful yet poorly developed approaches to explore the response of pathogen vectors in heterogeneous social-ecological systems, especially when field experiments cannot be performed. Methodology/Principal Findings We first present guidelines for the use of a spatially explicit IBM, to simulate population genetics of pathogen vectors in changing landscapes. We then applied our model with Triatoma brasiliensis, originally restricted to sylvatic habitats and now found in peridomestic and domestic habitats, posing as the most important Trypanosoma cruzi vector in Northeastern Brazil. We focused on the effects of vector migration rate, maximum dispersal distance and attraction by domestic habitat on T. brasiliensis population dynamics and spatial genetic structure. Optimized for T. brasiliensis using field data pairwise fixation index (FST) from microsatellite loci, our simulations confirmed the importance of these three variables to understand vector genetic structure at the landscape level. We then ran prospective scenarios accounting for land-use change (deforestation and urbanization), which revealed that human-induced land-use change favored higher genetic diversity among sampling points. Conclusions/Significance Our work shows that mechanistic models may be useful tools to link observed patterns with processes involved in the population genetics of tropical pathogen vectors in heterogeneous social-ecological landscapes. Our hope is that our study may provide a testable and applicable modeling framework to a broad community of epidemiologists for formulating scenarios of landscape change consequences on vector dynamics, with potential implications for their surveillance and control. PMID:25102068

Rebaudo, Francois; Costa, Jane; Almeida, Carlos E.; Silvain, Jean-Francois; Harry, Myriam; Dangles, Olivier

2014-01-01

194

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 media of consistently high quality is essential for the genetic manipulation of yeast. Autoclaving coli, yeast can be grown in either liquid media or on the surface of (or embedded in) solid agar plates

Winston, Fred

195

The intronome of budding yeasts.  

PubMed

Whatever their abundance in genomes, spliceosomal introns are the signature of eukaryotic genes. The sequence of Saccharomyces cerevisiae, achieved fifteen years ago, revealed that this yeast has very few introns, but conserved intron boundaries typical for an intron definition mechanism. With the improvement and the development of new sequencing technologies, yeast genomes have been extensively sequenced during the last decade. We took advantage of this plethora of data to compile and assess the intron content of the protein-coding genes of 13 genomes representative of the evolution of hemiascomycetous yeasts. We first observed that intron paucity is a general rule and that the fastest evolving genomes tend to lose their introns more rapidly (e.g. S. cerevisiae versus Yarrowia lipolytica). Noticeable differences were also confirmed for 5' splice sites and branch point sites (BP) as well as for the relative position of the BP. These changes seemed to be correlated with the lineage specific evolution of splicing factors. PMID:21819948

Neuvéglise, Cécile; Marck, Christian; Gaillardin, Claude

2011-01-01

196

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

197

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

198

?-1,3Glucanase is highly-expressed in laticifers of Hevea brasiliensis  

Microsoft Academic Search

Clones encoding ß-1,3-glucanase have been isolated from a Hevea cDNA library prepared from the latex of Hevea brasiliensis using a probe Nicotiana plumbaginifolia cDNA encoding ß-1,3-glucanase, gnl. Nucleotide sequence analysis showed that a 1.2 kb Hevea cDNA encoding a basic ß-1,3-glucanase showed 68% nucleotide homology to gnl cDNA. Northern blot analysis using the Hevea cDNA as probe detected a mRNA

Mee-Len Chye; Ka-Yun Cheung

1995-01-01

199

Oily yeasts as oleaginous cell factories  

Microsoft Academic Search

Oily yeasts have been described to be able to accumulate lipids up to 20% of their cellular dry weight. These yeasts represent\\u000a a minor proportion of the total yeast population, and only 5% of them have been reported as able to accumulate more than 25%\\u000a of lipids. The oily yeast genera include Yarrowia, Candida, Rhodotorula, Rhodosporidium, Cryptococcus, Trichosporon, and Lipomyces.

Jose Manuel Ageitos; Juan Andres Vallejo; Patricia Veiga-Crespo; Tomas G. Villa

2011-01-01

200

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

201

Yeast: A Research Organism for Teaching Genetics.  

ERIC Educational Resources Information Center

Explains why laboratory strains of bakers yeast, Saccharomyces cerevisiae, are particularly suited for classroom science activities. Describes the sexual life cycle of yeast and the genetic system with visible mutations. Presents an overview of activities that can be done with yeast and gives a source for teachers to obtain more information. (PR)

Manney, Thomas R.; Manney, Monta L.

1992-01-01

202

Recombinant protein production in yeasts.  

PubMed

Recombinant protein production is a multibillion-dollar market. The development of a new product begins with the choice of a production host. While one single perfect host for every protein does not exist, several expression systems ranging from bacterial hosts to mammalian cells have been established. Among them, yeast cell factories combine the advantages of being single cells, such as fast growth and easy genetic manipulation, as well as eukaryotic features including a secretory pathway leading to correct protein processing and post-translational modifications. In this respect, especially the engineering of yeast glycosylation to produce glycoproteins of human-like glycan structures is of great interest. Additionally, different attempts of cellular engineering as well as the design of different production processes that are leading to improved productivities are presented. With the advent of cheaper next-generation sequencing techniques, systems biotechnology approaches focusing on genome scale analyses will advance and accelerate yeast cell factories and thus recombinant protein production processes in the near future. In this review we summarize advantages and limitations of the main and most promising yeast hosts, including Saccharomyces cerevisiae, Pichia pastoris, and Hansenula polymorpha as those presently used in large scale production of heterologous proteins. PMID:22160907

Mattanovich, Diethard; Branduardi, Paola; Dato, Laura; Gasser, Brigitte; Sauer, Michael; Porro, Danilo

2012-01-01

203

Green synthesis of colloidal silver nanoparticles using natural rubber latex extracted from Hevea brasiliensis  

NASA Astrophysics Data System (ADS)

Colloidal silver nanoparticles were synthesized by an easy green method using thermal treatment of aqueous solutions of silver nitrate and natural rubber latex (NRL) extracted from Hevea brasiliensis. The UV-Vis spectra detected the characteristic surface plasmonic absorption band around 435 nm. Both NRL and AgNO 3 contents in the reaction medium have influence in the Ag nanoparticles formation. Lower AgNO 3 concentration led to decreased particle size. The silver nanoparticles presented diameters ranging from 2 nm to 100 nm and had spherical shape. The selected area electron diffraction (SAED) patterns indicated that the silver nanoparticles have face centered cubic (fcc) crystalline structure. FTIR spectra suggest that reduction of the silver ions are facilitated by their interaction with the amine groups from ammonia, which is used for conservation of the NRL, whereas the stability of the particles results from cis-isoprene binding onto the surface of nanoparticles. Therefore natural rubber latex extracted from H. brasiliensis can be employed in the preparation of stable aqueous dispersions of silver nanoparticles acting as a dispersing and/or capping agent. Moreover, this work provides a new method for the synthesis of silver nanoparticles that is simple, easy to perform, pollutant free and inexpensive.

Guidelli, Eder José; Ramos, Ana Paula; Zaniquelli, Maria Elisabete D.; Baffa, Oswaldo

2011-11-01

204

Sequence and expression analyses of ethylene response factors highly expressed in latex cells from Hevea brasiliensis.  

PubMed

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

205

[Development and application of EST-SSR markers in Hevea brasiliensis Muell. Arg].  

PubMed

Three thousand and ninety Unigenes were obtained from 10 778 Hevea brasiliensis ESTs. Four hundred and thirty SSRs were distributed in 353 Unigenes, which accounts for 11.42% of the total number of Unigenes. The frequency of SSRs was 1/3.93 kb. Dinucleotide and trinucleotide repeats were the dominant types among the obtained unigenes, accounting for 63.49% and 32.09%, respectively. TC/AG, CT/GA and CTT/GAA, AAG/TTC, and AGA/TCT were the most abundant motifs for dinucleotide and trinucleotide motifs. One hundred and forty-eight primer pairs were designed by PRIMER5.0 and 21 primer pairs were synthesized. Among them, 15 primer pairs can produce clear and stable bands, and the PCR products were screened in denaturing polyacrylamide gel following silver staining. Genetic diversity of 44 rubber clones were investigated with these primer pairs, and a dendrogram of 44 rubber clones was built. The results indicated that it is an effective and feasible way to develop EST-SSR markers from H. brasiliensis EST sequences, and the primers designed in this study can be used in genetic study of rubber tree. PMID:19273446

An, Ze-Wei; Zhao, Yan-Hong; Cheng, Han

2009-03-01

206

Biosorption of copper ions from dilute aqueous solutions on base treatedrubber ( Hevea brasiliensis) leaves powder: kinetics, isotherm, and biosorption mechanisms  

Microsoft Academic Search

The efficiency of sodium hydroxide treated rubber (Hevea brasiliensis) leaves powder (NHBL) for removing copper ions from aqueous solutions has been investigated. The effects of physicochemical parameters on biosorption capacities such as stirring speed, pH, biosorbent dose, initial concentrations of copper, and ionic strength were studied. The biosorption capacities of NHBL increased with increase in pH, stirring speed and copper

W. S. Wan Ngah; M. A. K. M. Hanafiah

2008-01-01

207

Development and characterization of novel expressed sequence tag-derived simple sequence repeat markers in Hevea brasiliensis (rubber tree).  

PubMed

Cultivated clones of Hevea brasiliensis have a narrow genetic base. In order to broaden the genetic base, it is first necessary to investigate the genetic diversity of wild populations. Expressed sequence tag-simple sequence repeat (EST-SSR) markers were developed to investigate the genetic diversity of Hevea populations. Four hundred and thirty microsatellites were identified and 148 primers were designed to amplify the loci. Twenty-nine primer pairs were synthesized and evaluated for their ability to detect genetic polymorphisms among 40 wild accessions of H. brasiliensis. Twenty-one of the 29 loci were polymorphic. The number of alleles per locus in the 40 accessions ranged from 2 to 7. H(O) and H(E) at each locus ranged from 0.0000 to 0.9000 and from 0.0000 to 0.8704, respectively. All 21 loci could amplify in H. brasiliensis, H. pauciflora, H. nitida, H. spruceana, and H. camargoana. The EST-SSR primers developed herein can be used in genetic diversity and structure studies in H. brasiliensis. PMID:24301960

An, Z W; Li, Y C; Zhai, Q L; Xie, L L; Zhao, Y H; Huang, H S

2013-01-01

208

Comparative study on the technological properties of latex and natural rubber from Hancornia speciosa Gomes and Hevea brasiliensis  

Technology Transfer Automated Retrieval System (TEKTRAN)

This work reports a systematic comparative study of the properties of natural lattices and rubbers extracted from Hancornia speciosa Gomes and Hevea brasiliensis [(Willd. ex Adr. de Juss.) Muell.-Arg.] (clone RRIM 600) trees from 11 collections in Brazil throughout 2004. Natural rubber latex particl...

209

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

210

Chemical and agronomic development of Kalanchoe brasiliensis Camb. and Kalanchoe pinnata Pers under light and temperature levels.  

PubMed

This study compares the development of Kalanchoe brasiliensis and Kalanchoe pinnata, which are medicinal species known as "saião" and "folha da fortuna" that are used interchangeably by the population for medicinal purposes. The experiment consisted of 20 plots/species planted in plastic bags with homogeneous substrate in a randomized design, which grown under light levels (25%, 50%, 70%, full sunlight) at environment temperature, and a treatment under a plastic with greater temperature range than the external environment. It was obtained for K. pinnata a greater plant height, total length of sprouts, stems, production and dry matter content of leaves than that obtained for K. brasiliensis, which achieved higher averages only for the length of lateral branches. The species showed increases in height, which varied in inverse proportion to the light, and it was observed the influence of temperature in K. pinnata. The production and dry matter content of leaves were proportional to the luminosity; the same occurred in the thickness of leaves for K. brasiliensis. In the swelling index and Brix degree, K. brasiliensis showed higher averages than K. pinnata. In relation to the total content of flavonoids it was not observed significant differences for both species. The analyzed parameters showed the main differences in the agronomic development of the two species. PMID:22146966

Cruz, Bruna P; Chedier, Luciana M; Fabri, Rodrigo L; Pimenta, Daniel S

2011-12-01

211

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

212

Precipitation of Hevea brasiliensis Latex Proteins with Trichloroacetic Acid and Phosphotungstic Acid in Preparation for the Lowry Protein Assay  

Microsoft Academic Search

Many proteins derived from the latex of Hevea brasiliensis that remain soluble in trichloroacetic acid (TCA) can be precipitated by phosphotungstic acid (PTA). A combination of 5% TCA and 0.2% PTA precipitates a wide range of proteins effectively even when they are present in low concentrations (below 1 ?g ml?1). In addition to its protein purification function, acid precipitation also

H. Y. Yeang; F. Yusof; L. Abdullah

1995-01-01

213

Adsorption of Bismark Brown dye on activated carbons prepared from rubberwood sawdust ( Hevea brasiliensis) using different activation methods  

Microsoft Academic Search

Hevea brasiliensis or rubberwood tree, as it is commonly known finds limited use once the latex has been tapped. The sawdust of this tree is chosen to ascertain it viability as a precursor for activation. The carbons thus obtained were characterized in terms of iodine, methylene blue number and surface area. The best carbon in each method was utilized to

B. G. Prakash Kumar; Lima Rose Miranda; M. Velan

2005-01-01

214

In vivo sensitization to purified Hevea brasiliensis proteins in health care workers sensitized to natural rubber latex  

Microsoft Academic Search

Background: Thirteen proteins of natural rubber latex (Hevea brasiliensis) known to bind human IgE have been isolated and characterized as Hev b allergens. However, the in vivo importance of native Hev b allergens has not been defined in health care workers (HCWs) with natural rubber latex (NRL) allergy. Objectives: The principal aim of this study was to identify the major

David I. Bernstein; Raymond E. Biagini; Ravi Karnani; Robert Hamilton; Karen Murphy; Cheryl Bernstein; Siti Arija M. Arif; Brian Berendts; H. Y. Yeang

2003-01-01

215

Yeast DEL assay detects clastogens.  

PubMed

Chromosomal rearrangements, including DNA deletions are involved in carcinogenesis. The deletion (DEL) assay scoring for DNA deletions in the yeast Saccharomyces cerevisiae is able to detect a wide range of carcinogens. Among approximately 60 compounds of known carcinogenic activity, the DEL assay detected 86% correctly whereas the Ames Salmonella assay detected only 30% correctly [R.J. Brennan, R.H. Schiestl, Detecting carcinogens with the yeast DEL assay, Methods Mol. Biol. 262 (2004) 111-124]. Since the DEL assay is highly inducible by DNA double strand breaks, this study examined the utility of the DEL assay for detecting clastogens. Ten model compounds, with varied mechanisms of genotoxicity, were examined for their effect on the frequency of DNA deletions with the DEL assay. The compounds tested were: actinomycin D, camptothecin, methotrexate and 5-fluorodeoxyuridine, which are anticancer agents, noscapine and furosemide are therapeutics, acridine, methyl acrylate and resorcinol are industrial chemicals and diazinon is an insecticide. The in vitro micronucleus assay (IVMN) in CHO cells, a commonly used tool for detection of clastogens, was performed on the same compounds and the results of the two assays were compared. The results of our study show that there is 70% concordance in the presence of metabolic activation (rat liver S9) and 80% concordance in the absence of metabolic activation between the DEL assay and the standard in vitro micronucleus assay. The lack of cytotoxicity observed for four of the ten compounds examined indicates limited diffusion of lipophilic compounds across the yeast cell wall. Thus, the development of a more permeable yeast tester strain is expected to greatly improve concordance of the DEL assay with the IVMN assay. The yeast DEL assay is inexpensive, amenable to automation and requires less expertise to perform than the IVMN. Thus, it has a strong potential as a robust, fast and economical screen for detecting clastogens in vitro. PMID:15781217

Kirpnick, Zhanna; Homiski, Michael; Rubitski, Elizabeth; Repnevskaya, Marina; Howlett, Niall; Aubrecht, Jiri; Schiestl, Robert H

2005-04-01

216

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

217

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

218

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:25165976

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

2014-08-22

219

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

PubMed Central

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; de Souza, Rita de Cássia Moreira; Barbosa, Silvia Ermelinda; Xavier, Samanta Cristina das Chagas; Jansen, Ana Maria; Ramalho, Relrison Dias; Diotaiut, Liléia

2014-01-01

220

The left lung is preferentially targeted during experimental paracoccidioidomycosis in C57BL/6 mice  

PubMed Central

Paracoccidioidomycosis (PCM) is a chronic systemic mycosis caused by the inhalation of the thermally dimorphic fungus Paracoccidioides brasiliensis as well as the recently described P. lutzii. Because the primary infection occurs in the lungs, we investigated the differential involvement of the right and left lungs in experimental P. brasiliensis infection. Lungs were collected from C57BL/6 mice at 70 days after intravenous infection with 1×106 yeast cells of a virulent strain of P. brasiliensis (Pb18). The left lung, which in mice is smaller and has fewer lobes than the right lung, yielded increased fungal recovery associated with a predominant interleukin-4 response and diminished synthesis of interferon-? and nitric oxide compared with the right lung. Our data indicate differential involvement of the right and left lungs during experimental PCM. This knowledge emphasizes the need for an accurate, standardized protocol for tissue collection during studies of experimental P. brasiliensis infection, since experiments using the same lungs favor the collection of comparable data among different mice. PMID:24141611

Tristão, F.S.M.; Rocha, F.A.; Dias, F.C.; Rossi, M.A.; Silva, J.S.

2013-01-01

221

The Pivotal Role of 5-Lipoxygenase-Derived LTB4 in Controlling Pulmonary Paracoccidioidomycosis  

PubMed Central

Leukotrienes (LTs) produced from arachidonic acid by the action of 5-lipoxygenase (5-LO) are classical mediators of inflammatory responses. However, studies published in the literature regarding these mediators are contradictory and it remains uncertain whether these lipid mediators play a role in host defense against the fungal pathogen Paracoccidioides brasiliensis. To determine the involvement of LTs in the host response to pulmonary infection, wild-type and LT-deficient mice by targeted disruption of the 5-lipoxygenase gene (knockout mice) were studied following intratracheal challenge with P. brasiliensis yeasts. The results showed that infection is uniformly fatal in 5-LO-deficient mice and the mechanisms that account for this phenotype are an exacerbated lung injury and higher fungal pulmonary burden. Genetic ablation or pharmacological inhibition of LTs resulted in lower phagocytosis and fungicidal activity of macrophages in vitro, suggesting that deficiency in fungal clearance seems to be secondary to the absence of activation in 5-LO?/? macrophages. Exogenous LTB4 restored phagocytosis and fungicidal activity of 5-LO?/? macrophages. Moreover, P. brasiliensis killing promoted by LTB4 was dependent on nitric oxide (NO) production by macrophages. Taken together, these results reveal a fundamental role for 5-LO-derived LTB4 in the protective response to P. brasiliensis infection and identify relevant mechanisms for the control of fungal infection during the early stages of the host immune response. PMID:23991239

Santos, Patrícia Campi; Santos, Daniel Assis; Ribeiro, Lucas Secchim; Fagundes, Caio Tavares; de Paula, Talles Prosperi; Avila, Thiago Vinícius; Baltazar, Ludmila de Matos; Madeira, Mila Moreira; Cruz, Rosana de Carvalho; Dias, Ana Carolina Fialho; Machado, Fabiana Simão; Teixeira, Mauro Martins; Cisalpino, Patrícia Silva; Souza, Danielle G.

2013-01-01

222

Cultivated strains of Agaricus bisporus and A. brasiliensis: chemical characterization and evaluation of antioxidant and antimicrobial properties for the final healthy product--natural preservatives in yoghurt.  

PubMed

Agaricus bisporus (J. E. Lange) Emil J. Imbach and Agaricus brasiliensis Wasser, M. Didukh, Amazonas & Stamets are edible mushrooms. We chemically characterized these mushrooms for nutritional value, hydrophilic and lipophilic compounds. The antioxidant and antimicrobial activities of methanolic and ethanolic extracts were assessed. Hepatotoxicity was also evaluated. The ethanolic extract of both species was tested for inhibition of Listeria monocytogenes growth in yoghurt. Both species proved to be a good source of bioactive compounds. A. brasiliensis was richer in polyunsaturated fatty acids and revealed the highest concentration of phenolic acids, and tocopherols. A. bisporus showed the highest monounsaturated fatty acids and ergosterol contents. A. brasiliensis revealed the highest antioxidant potential, and its ethanolic extract displayed the highest antibacterial potential; the methanolic extract of A. bisporus revealed the highest antifungal activity. A. brasiliensis possessed better preserving properties in yoghurt. PMID:24881564

Stojkovi?, Dejan; Reis, Filipa S; Glamo?lija, Jasmina; ?iri?, Ana; Barros, Lillian; Van Griensven, Leo J L D; Ferreira, Isabel C F R; Sokovi?, Marina

2014-07-25

223

Original article Effect of a viable yeast culture on digestibility  

E-print Network

with 5 g yeast supplement (Saccharomyces cerevisiae, Biosafe) per day in a latin square design. Diets by yeast treatment. Supplementation of yeast in- creased acetate: propionate ratio, butyrate, isoacids, p number in the rumen fluid rapidly declined when dietary yeast was ceased. Further- more, yeast cells

Boyer, Edmond

224

Sterols in yeast subcellular fractions.  

PubMed

Yeast is the most primitive organism synthesizing substantial amounts of sterols. Because of this eucaryotic organism's versatility in growth conditions, ease of culture, well-defined genetic mechanism, and characteristic subcellar architecture, it is readily applied to studies of the role of sterols in the general economy of the cell. Sterols exist in two major forms, as the free sterol, or esterified with long chain fatty acids. The importance of sterols for this organism can be demonstrated using a naturally occurring antimycotic azasterol. This agent inhibits yeast growth. Three effects are seen on sterol synthesis: inhibition of the enzymes delta14-reductase, sterol methyltransferase, and methylene reductase. Cells cultured on respiratory substrates are more sensitive to inhibition than are cells growing on glucose. We have demonstrated a relationship between respiratory competency and sterol biosynthesis in this organism. Many mutants altered in sterol synthesis are respirationally defective and must grow fermentatively. One clone has temperature conditional respiration. Experiments with purified mitochondria, prepared from this mutant and its isogenic wildtype, show that the mutant organism is able to respire at the higher temperature but lacks the ability to couple respiration to phosphorylation. No similar loss is seen in the wild-type clones. Data are given which support the proposal that, for inclusion in mitochondrial structures, yeast cells may discriminate among sterols available from the total sterol pool in favor of ergosterol. PMID:364234

Parks, L W; McLean-Bowen, C; Taylor, F R; Hough, S

1978-10-01

225

Pheromone Signaling Pathways in Yeast  

NSDL National Science Digital Library

The actions of many extracellular stimuli are elicited by complexes of cell surface receptors, heterotrimeric guanine nucleotide–binding proteins (G proteins), and mitogen-activated protein kinase (MAPK) complexes. Analysis of haploid yeast cells and their response to peptide mating pheromones has produced important advances in the understanding of G protein and MAPK signaling mechanisms. Many of the components, their interrelationships, and their regulators were first identified in yeast. Examples include definitive demonstration of a positive signaling role for G protein βγ subunits, the discovery of a three-tiered structure of the MAPK module, development of the concept of a kinase-scaffold protein, and the discovery of the first regulator of G protein signaling protein. New and powerful genomic, proteomic, and computational approaches available in yeast are beginning to uncover new pathway components and interactions and have revealed their presence in unexpected locations within the cell. This updated Connections Map in the Database of Cell Signaling includes several major revisions to this prototypical signal response pathway.

Henrik G. Dohlman (University of North Carolina;Department of Biochemistry and Biophysics REV); Janna E. Slessareva (University of North Carolina;Department of Biochemistry and Biophysics REV)

2006-12-05

226

Biopharmaceutical discovery and production in yeast.  

PubMed

The selection of an expression platform for recombinant biopharmaceuticals is often centered upon suitable product titers and critical quality attributes, including post-translational modifications. Although notable differences between microbial, yeast, plant, and mammalian host systems exist, recent advances have greatly mitigated any inherent liabilities of yeasts. Yeast expression platforms are important to both the supply of marketed biopharmaceuticals and the pipelines of novel therapeutics. In this review, recent advances in yeast-based expression of biopharmaceuticals will be discussed. The advantages of using glycoengineered yeast as a production host and in the discovery space will be illustrated. These advancements, in turn, are transforming yeast platforms from simple production systems to key technological assets in the discovery and selection of biopharmaceutical lead candidates. PMID:25014890

Meehl, Michael A; Stadheim, Terrance A

2014-12-01

227

Yeasts Diversity in Fermented Foods and Beverages  

NASA Astrophysics Data System (ADS)

People across the world have learnt to culture and use the essential microorganisms for production of fermented foods and alcoholic beverages. A fermented food is produced either spontaneously or by adding mixed/pure starter culture(s). Yeasts are among the essential functional microorganisms encountered in many fermented foods, and are commercially used in production of baker's yeast, breads, wine, beer, cheese, etc. In Asia, moulds are predominant followed by amylolytic and alcohol-producing yeasts in the fermentation processes, whereas in Africa, Europe, Australia and America, fermented products are prepared exclusively using bacteria or bacteria-yeasts mixed cultures. This chapter would focus on the varieties of fermented foods and alcoholic beverages produced by yeasts, their microbiology and role in food fermentation, widely used commercial starters (pilot production, molecular aspects), production technology of some common commercial fermented foods and alcoholic beverages, toxicity and food safety using yeasts cultures and socio-economy

Tamang, Jyoti Prakash; Fleet, Graham H.

228

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

229

Anthocyanins from Eugenia brasiliensis edible fruits as potential therapeutics for COPD treatment  

PubMed Central

Nine anthocyanins (1–9) from the edible fruits of Eugenia brasiliensis were identified by HPLC-PDA and LC-MS, and seven of these are described for the first time in this Brazilian fruit. Two of the major anthocyanins, delphinidin (8) and cyanidin (9), were studied for their inhibitory activity against chemokine interleukin-8 (IL-8) production before and after cigarette smoke extract (CSE) treatment of cells. In non-treated cells the amount of IL-8 was unchanged following treatment with cyanidin and delphinidin in concentrations 0.1–10 M. Both delphinidin (8) and cyanidin (9) decreased the production of IL-8 in treated cells, at 1 M and 10 M, respectively. Delphinidin (8) demonstrated IL-8 inhibition in the CSE treated cells in a dose-dependent manner. PMID:25005941

Flores, Gema; Dastmalchi, Keyvan; Paulino, Sturlainny; Whalen, Kathleen; Dabo, Abdoulaye J.; Reynertson, Kurt A.; Foronjy, Robert F.; D Armiento, Jeanine M.; Kennelly, Edward J.

2012-01-01

230

Climate and natural production of rubber ( Hevea brasiliensis) in Xishuangbanna, southern part of Yunnan province, China  

NASA Astrophysics Data System (ADS)

According to the author's and his collaborators' investigations, the climate influences the growth of rubber trees ( Hevea brasiliensis) in Xishuangbanna, the southern part of Yunnan Province, China, in at least four aspects: (1) The yield of latex per tapping and the final yield of dry rubber per tree per year or per unit area per year; (2) the growth rate, as expressed by increment of girth in cm; (3) the survival during the over-wintering period; (4) the initiation or suppression of certain diseases; In this paper the author would like to describe the influence of climatic elements on yield of latex and on survival during the over-wintering period. As for the other two aspects, only general comments are given.

Jiang, Ailiang

1988-12-01

231

Influence of soil, plant and meteorological factors on water relations and yield in Hevea brasiliensis  

NASA Astrophysics Data System (ADS)

Influence of factors governing the soil-plantatmosphere system on components of water relations and yield was studied in two clones of rubber tree, Hevea brasiliensis, viz. RRII 105 and RRII 118. Clonal variations were evident in yield and yield components and associated physiological parameters in response to soil moisture status and meteorological factors. Observations made during different seasons indicatedvariations in yield are attributed to differences in plugging index and initial flow rates, to the major yield components and also variations in components of water relations as influenced by meteorological factors. Among the two clones, RRII 105 was found to be fairly drought tolerant compared to RRII 118. RRII 105 was found to respond well to dry weather through higher stomatal resistances, higher leaf water potentials, lowered transpirational water loss and lower relative transpiration ratios, while RRII 118 was susceptible to stress situations.

Rao, G. Gururaja; Rao, P. Sanjeeva; Rajagopal, R.; Devakumar, A. S.; Vijayakumar, K. R.; Sethuraj, M. R.

1990-09-01

232

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

233

Evaluation of Automated Yeast Identification System  

NASA Technical Reports Server (NTRS)

One hundred and nine teleomorphic and anamorphic yeast isolates representing approximately 30 taxa were used to evaluate the accuracy of the Biolog yeast identification system. Isolates derived from nomenclatural types, environmental, and clinica isolates of known identity were tested in the Biolog system. Of the isolates tested, 81 were in the Biolog database. The system correctly identified 40, incorrectly identified 29, and was unable to identify 12. Of the 28 isolates not in the database, 18 were given names, whereas 10 were not. The Biolog yeast identification system is inadequate for the identification of yeasts originating from the environment during space program activities.

McGinnis, M. R.

1996-01-01

234

Role of glucose signaling in yeast metabolism  

SciTech Connect

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

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

1996-10-05

235

Prevention of Yeast Spoilage in Feed and Food by the Yeast Mycocin HMK  

Microsoft Academic Search

The yeast Williopsis mrakii produces a mycocin or yeast killer toxin designated HMK; this toxin exhibits high thermal stability, high pH stability, and a broad spectrum of activity against other yeasts. We describe con- struction of a synthetic gene for mycocin HMK and heterologous expression of this toxin in Aspergillus niger. Mycocin HMK was fused to a glucoamylase protein carrier,

K. F. Lowes; C. A. Shearman; J. Payne; D. MacKenzie; D. B. Archer; R. J. Merry; M. J. Gasson

2000-01-01

236

INDISIM-YEAST, an individual-based model to study yeast population in batch cultures  

Microsoft Academic Search

INDISIM-YEAST, an individual-based simulator, models the evolution of a yeast population by setting up rules of behaviour for each individual cell according to their own biological rules and characteristics. It takes into account the uptake, metabolism, budding reproduction and viability of the yeast cells, over a period of time in the bulk of a liquid medium, occupying a three dimensional

Marta Ginovart; Joan Xifré; Daniel López; Moises Silbert

237

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

238

Identification of a Hevea brasiliensis Latex Manganese Superoxide Dismutase (Hev b 10) as a Cross-Reactive Allergen  

Microsoft Academic Search

Background: Cross-reactive allergens play an increasingly important role in latex allergy in complicating both the diagnosis and time course of allergic symptoms. Manganese superoxide dismutase (MnSOD), a ubiquitous protein of prokaryotic and eukaryotic organisms, was described as a cross-reactive allergen in Aspergillus fumigatus. Little information is available on the importance of this pan-allergen in Hevea brasiliensis latex. The aim of

Stefan Wagner; Slawomir Sowka; Christina Mayer; Reto Crameri; Margit Focke; Viswanath P. Kurup; Otto Scheiner; Heimo Breiteneder

2001-01-01

239

Hevea brasiliensis REF (Hev b 1) and SRPP (Hev b 3): An overview on rubber particle proteins.  

PubMed

This review article aims to gather all the knowledge on two important proteins associated with Hevea brasiliensis rubber particles: namely the rubber elongation factor (REF) and the small rubber particle protein (SRPP). It covers more then three decades of research on these two proteins and their homologues in plants, and particularly emphasizes on the different possible properties or functions of these various proteins found in plants. PMID:25019490

Berthelot, Karine; Lecomte, Sophie; Estevez, Yannick; Peruch, Frédéric

2014-11-01

240

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

PubMed Central

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 confirmed by analysis of its enzymatic activity on H2O2 and by a double-staining method on a nondenaturing polyacrylamide gel with 3,3?-diaminobenzidine and ferricyanide; the result showed only catalase activity, but no peroxidase. By using one of the internal amino acid sequences and a consensus catalase motif (VGNNTP), we were able to design a PCR assay that generated a 500-bp PCR product. The amplicon was analyzed, and the nucleotide sequence was compared to the GenBank database with the observation of high homology to other bacterial and eukaryotic catalases. A PCR assay based on this target sequence was performed with primers NB10 and NB11 to confirm the presence of the NB10-NB11 gene fragment in several N. brasiliensis strains isolated from mycetoma. The same assay was used to determine whether there were homologous sequences in several type strains from the genera Nocardia, Rhodococcus, Gordona, and Streptomyces. All of the N. brasiliensis strains presented a positive result but only some of the actinomycetes species tested were positive in the PCR assay. In order to confirm these findings, genomic DNA was subjected to Southern blot analysis. A 1.7-kbp band was observed in the N. brasiliensis strains, and bands of different molecular weight were observed in cross-reacting actinomycetes. Sequence analysis of the amplicons of selected actinomycetes showed high homology in this catalase fragment, thus demonstrating that this protein is highly conserved in this group of bacteria. PMID:10325357

Vera-Cabrera, Lucio; Johnson, Wendy M.; Welsh, Oliverio; Resendiz-Uresti, Francisco L.; Salinas-Carmona, Mario C.

1999-01-01

241

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

242

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

243

Hev b 8, the Hevea brasiliensis Latex Profilin, Is a Cross-Reactive Allergen of Latex, Plant Foods and Pollen  

Microsoft Academic Search

Background: Plant profilins are important pan-allergens. They are responsible for a significant percentage of pollen-related allergies. Limited information is available about their involvement in the latex-fruit syndrome and the cross-reactivities between latex and pollen. We aimed to clone and express the Hevea brasiliensis latex profilin to investigate its allergological significance and serological cross-reactivities to profilins from plant foods and pollens.

Erika Ganglberger; Christian Radauer; Stefan Wagner; Gabriel Ó Ríordáin; Donald H. Beezhold; Randolf Brehler; Bodo Niggemann; Otto Scheiner; Erika Jensen-Jarolim; Heimo Breiteneder

2001-01-01

244

Wound-Induced Accumulation of mRNA Containing a Hevein Sequence in Laticifers of Rubber Tree (Hevea brasiliensis)  

Microsoft Academic Search

Hevein is a chitin-binding protein that is present in laticifers of the rubber tree (Hevea brasiliensis). A cDNA clone (HEV1) encoding hevein was isolated by using the polymerase chain reaction with mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea latex cDNA library as a template. HEV1 is 1018 base pairs long and includes an open

Willem Broekaert; Hyung-Il Lee; Anil Kush; Nam-Hai Chua; Natasha Raikhel

1990-01-01

245

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

246

Expression and characterization of active site mutants of hevamine, a chitinase from the rubber tree Hevea brasiliensis  

Microsoft Academic Search

Hevamine is a chitinase from the rubber tree Hevea brasiliensis. Its active site contains Asp125, Glu127, and Tyr183, which interact with the -1 sugar residue of the substrate. To investigate their role in catalysis, we have successfully expressed wild-type enzyme and mutants of these residues as inclusion bodies in Escherichia coli. After refolding and purification they were characterized by both

Bauke W. Dijkstra; Mark Sibbald; Henriëtte J. Rozeboom; Jaap J. Beintema; Evert Bokma

2002-01-01

247

CaMV 35S promoter directs ?-glucuronidase expression in the laticiferous system of transgenic Hevea brasiliensis (rubber tree)  

Microsoft Academic Search

Hevea brasiliensis anther calli were genetically transformed using Agrobacterium GV2260 (p35SGUSINT) that harboured the ?-glucuronidase (gus) and neomycin phosphotransferase (nptII) genes. ?-Glucuronidase protein (GUS) was expressed in the leaves of kanamycin-resistant plants that were regnerated, and the presence\\u000a of the gene was confirmed by Southern analysis. GUS was also observed to be expressed in the latex and more importantly in

P. Arokiaraj; H. Yeet Yeang; K. Fong Cheong; S. Hamzah; H. Jones; S. Coomber; B. V. Charlwood

1998-01-01

248

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

249

YMDB: the Yeast Metabolome Database.  

PubMed

The Yeast Metabolome Database (YMDB, http://www.ymdb.ca) is a richly annotated 'metabolomic' database containing detailed information about the metabolome of Saccharomyces cerevisiae. Modeled closely after the Human Metabolome Database, the YMDB contains >2000 metabolites with links to 995 different genes/proteins, including enzymes and transporters. The information in YMDB has been gathered from hundreds of books, journal articles and electronic databases. In addition to its comprehensive literature-derived data, the YMDB also contains an extensive collection of experimental intracellular and extracellular metabolite concentration data compiled from detailed Mass Spectrometry (MS) and Nuclear Magnetic Resonance (NMR) metabolomic analyses performed in our lab. This is further supplemented with thousands of NMR and MS spectra collected on pure, reference yeast metabolites. Each metabolite entry in the YMDB contains an average of 80 separate data fields including comprehensive compound description, names and synonyms, structural information, physico-chemical data, reference NMR and MS spectra, intracellular/extracellular concentrations, growth conditions and substrates, pathway information, enzyme data, gene/protein sequence data, as well as numerous hyperlinks to images, references and other public databases. Extensive searching, relational querying and data browsing tools are also provided that support text, chemical structure, spectral, molecular weight and gene/protein sequence queries. Because of S. cervesiae's importance as a model organism for biologists and as a biofactory for industry, we believe this kind of database could have considerable appeal not only to metabolomics researchers, but also to yeast biologists, systems biologists, the industrial fermentation industry, as well as the beer, wine and spirit industry. PMID:22064855

Jewison, Timothy; Knox, Craig; Neveu, Vanessa; Djoumbou, Yannick; Guo, An Chi; Lee, Jacqueline; Liu, Philip; Mandal, Rupasri; Krishnamurthy, Ram; Sinelnikov, Igor; Wilson, Michael; Wishart, David S

2012-01-01

250

Prevention of Yeast Spoilage in Feed and Food by the Yeast Mycocin HMK  

PubMed Central

The yeast Williopsis mrakii produces a mycocin or yeast killer toxin designated HMK; this toxin exhibits high thermal stability, high pH stability, and a broad spectrum of activity against other yeasts. We describe construction of a synthetic gene for mycocin HMK and heterologous expression of this toxin in Aspergillus niger. Mycocin HMK was fused to a glucoamylase protein carrier, which resulted in secretion of biologically active mycocin into the culture media. A partial purification protocol was developed, and a comparison with native W. mrakii mycocin showed that the heterologously expressed mycocin had similar physiological properties and an almost identical spectrum of biological activity against a number of yeasts isolated from silage and yoghurt. Two food and feed production systems prone to yeast spoilage were used as models to assess the ability of mycocin HMK to act as a biocontrol agent. The onset of aerobic spoilage in mature maize silage was delayed by application of A. niger mycocin HMK on opening because the toxin inhibited growth of the indigenous spoilage yeasts. This helped maintain both higher lactic acid levels and a lower pH. In yoghurt spiked with dairy spoilage yeasts, A. niger mycocin HMK was active at all of the storage temperatures tested at which yeast growth occurred, and there was no resurgence of resistant yeasts. The higher the yeast growth rate, the more effective the killing action of the mycocin. Thus, mycocin HMK has potential applications in controlling both silage spoilage and yoghurt spoilage caused by yeasts. PMID:10698773

Lowes, K. F.; Shearman, C. A.; Payne, J.; MacKenzie, D.; Archer, D. B.; Merry, R. J.; Gasson, M. J.

2000-01-01

251

Growth requirements of san francisco sour dough yeasts and bakers' yeast.  

PubMed

The growth requirements of several yeasts isolated from San Francisco sour dough mother sponges were compared with those of bakers' yeast. The sour dough yeasts studied were one strain of Saccharomyces uvarum, one strain of S. inusitatus, and four strains of S. exiguus. S. inusitatus was the only yeast found to have an amino acid requirement, namely, methionine. All of the yeasts had an absolute requirement for pantothenic acid and a partial requirement for biotin. Inositol was stimulatory to all except bakers' yeast. All strains of S. exiguus required niacin and thiamine. Interestingly, S. inusitatus, the only yeast that required methionine, also needed folic acid. For optimal growth of S. exiguus in a molasses medium, supplementation with thiamine was required. PMID:16345154

Henry, N

1976-03-01

252

Yeast flora of grape berries during ripening  

Microsoft Academic Search

The yeast flora associated with the surface of grapes during ripening was studied with regard to different sectors of the grape skin and the position in the bunch by means of traditional as well as more vigorous preisolation and precounting treatments. The yeast number per square centimeter of skin increases with ripening and is highest in the area immediately surrounding

Gianfranco Rosini; Federico Federici; Alessandro Martini

1982-01-01

253

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

254

Yeast: An Experimental Organism for Modern Biology.  

ERIC Educational Resources Information Center

Discusses the applicability and advantages of using yeasts as popular and ideal model systems for studying and understanding eukaryotic biology at the cellular and molecular levels. Cites experimental tractability and the cooperative tradition of the research community of yeast biologists as reasons for this success. (RT)

Botstein, David; Fink, Gerald R.

1988-01-01

255

The wine and beer yeast Dekkera bruxellensis  

PubMed Central

Recently, the non-conventional yeast Dekkera bruxellensis has been gaining more and more attention in the food industry and academic research. This yeast species is a distant relative of Saccharomyces cerevisiae and is especially known for two important characteristics: on the one hand, it is considered to be one of the main spoilage organisms in the wine and bioethanol industry; on the other hand, it is 'indispensable' as a contributor to the flavour profile of Belgium lambic and gueuze beers. Additionally, it adds to the characteristic aromatic properties of some red wines. Recently this yeast has also become a model for the study of yeast evolution. In this review we focus on the recently developed molecular and genetic tools, such as complete genome sequencing and transformation, to study and manipulate this yeast. We also focus on the areas that are particularly well explored in this yeast, such as the synthesis of off-flavours, yeast detection methods, carbon metabolism and evolutionary history. © 2014 The Authors. Yeast published by John Wiley & Sons, Ltd. PMID:24932634

Schifferdecker, Anna Judith; Dashko, Sofia; Ishchuk, Olena P; Piškur, Jure

2014-01-01

256

The yeast expression system for recombinant glycosyltransferases  

Microsoft Academic Search

Glycosyltransferases are increasingly being used for in vitro synthesis of oligosaccharides. Since these enzymes are difficult to purify from natural sources, expression systems for soluble forms of the recombinant enzymes have been developed. This review focuses on the current state of development of yeast expression systems. Two yeast species have mainly been used, i.e. Saccharomyces cerevisiae and Pichia pastoris. Safety

Martine Malissard; Steffen Zeng; Eric G. Berger

1999-01-01

257

Production of serpins using yeast expression systems  

Microsoft Academic Search

Serpins occupy a unique niche in the field of biology. As more of them are discovered, the need to produce sufficient quantities of each to aid experimental and therapeutic research increases. Yeast expression systems are well suited for the production of recombinant serpins. The genetics of many yeast species is well understood and readily manipulated to induce the targeted over-production

Philip A. Pemberton; Phillip I. Bird

2004-01-01

258

YEAST MEIOSIS Sister kinetochores are mechanically  

E-print Network

YEAST MEIOSIS Sister kinetochores are mechanically fused during meiosis I in yeast Krishna K Production of healthy gametes requires a reductional meiosis I division in which replicated sister chromatids comigrate, rather than separate as in mitosis or meiosis II. Fusion of sister kinetochores during meiosis I

Asbury, Chip

259

Chronological aging leads to apoptosis in yeast  

Microsoft Academic Search

uring the past years, yeast has been successfully established as a model to study mechanisms of apoptotic regulation. However, the beneficial effects of such a cell suicide program for a unicellular organism remained obscure. Here, we demonstrate that chronologi- cally aged yeast cultures die exhibiting typical markers of apoptosis, accumulate oxygen radicals, and show caspase activation. Age-induced cell death is

Eva Herker; Helmut Jungwirth; Katharina A. Lehmann; Corinna Maldener; Kai-Uwe Fröhlich; Silke Wissing; Sabrina Büttner; Markus Fehr; Stephan Sigrist; Frank Madeo

2004-01-01

260

Definition, classification and nomenclature of the yeasts  

Technology Transfer Automated Retrieval System (TEKTRAN)

This submission includes sections for the Preface, Use of this Book, Table of Contents and a chapter entitled Definition, classification and nomenclature of the yeasts, which are to be published in The Yeasts, A Taxonomic Study, 5th edition. This book has been prepared by a team of international ex...

261

Enological functions of parietal yeast mannoproteins.  

PubMed

Parietal yeast mannoproteins play a very important role in the overall vinification process. Their production and release, both during winemaking and aging on lees, depends on the specific yeast strain and the nutritional conditions. The following enological functions of parietal yeast mannoproteins have been described: (a) adsorption of ochratoxin A; (b) combination with phenolic compounds; (c) increased growth of malolactic bacteria; (d) inhibition of tartrate salt crystallization; (e) interaction with flor wines; (f) prevention of haze; (g) reinforcement of aromatic components; (h) wine enrichment during aging on fine lees; (i) yeast flocculation and autolysis in sparkling wines. Further discoveries related to their enological functions are foreseeable. Yeast-derived mannoproteins may well induce chemical, sensorial and health benefits, thus greatly improving wine quality. PMID:16622788

Caridi, Andrea

2006-01-01

262

Growing yeast into cylindrical colonies.  

PubMed

Microorganisms often form complex multicellular assemblies such as biofilms and colonies. Understanding the interplay between assembly expansion, metabolic yield, and nutrient diffusion within a freely growing colony remains a challenge. Most available data on microorganisms are from planktonic cultures, due to the lack of experimental tools to control the growth of multicellular assemblies. Here, we propose a method to constrain the growth of yeast colonies into simple geometric shapes such as cylinders. To this end, we designed a simple, versatile culture system to control the location of nutrient delivery below a growing colony. Under such culture conditions, yeast colonies grow vertically and only at the locations where nutrients are delivered. Colonies increase in height at a steady growth rate that is inversely proportional to the cylinder radius. We show that the vertical growth rate of cylindrical colonies is not defined by the single-cell division rate, but rather by the colony metabolic yield. This contrasts with cells in liquid culture, in which the single-cell division rate is the only parameter that defines the population growth rate. This method also provides a direct, simple method to estimate the metabolic yield of a colony. Our study further demonstrates the importance of the shape of colonies on setting their expansion. We anticipate that our approach will be a starting point for elaborate studies of the population dynamics, evolution, and ecology of microbial colonies in complex landscapes. PMID:24853750

Vulin, Clément; Di Meglio, Jean-Marc; Lindner, Ariel B; Daerr, Adrian; Murray, Andrew; Hersen, Pascal

2014-05-20

263

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

PubMed

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 attempts to establish these fungi in single-species pot cultures with Plantago lanceolata as host were unsuccessful. Nevertheless, based on a 1.5-kb DNA fragment spanning part of the small subunit rRNA gene, the internal transcribed spacer region and part of the large subunit rRNA gene, both these species could be detected directly in field-sampled roots, together with one uncultured species each of Scutellospora, Rhizophagus (former Glomus group Ab, or 'Glomus intraradices clade') and Acaulospora. Whereas A. alpina has characteristic morphological similarities to other species in its genus, A. brasiliensis morphologically has little in common with any other species in Ambispora. The molecular phylogeny, DNA barcoding and morphological evidence clearly place A. brasiliensis in the genus Acaulospora. We therefore rename the species, reported from Brazil and Scotland, as Acaulospora brasiliensis comb. nov., and discuss ecological aspects of the very different environments from which A. brasiliensis and A. alpina have been reported. PMID:21336507

Krüger, Manuela; Walker, Christopher; Schüssler, Arthur

2011-08-01

264

Cloning and characterization of the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway genes of a natural-rubber producing plant, Hevea brasiliensis.  

PubMed

Natural rubber is synthesized as rubber particles in the latex, the fluid cytoplasm of laticifers, of Hevea brasiliensis. Although it has been found that natural rubber is biosynthesized through the mevalonate pathway, the involvement of an alternative 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway is uncertain. We obtained all series of the MEP pathway candidate genes by analyzing expressed sequence tag (EST) information and degenerate PCR in H. brasiliensis. Complementation experiments with Escherichia coli mutants were performed to confirm the functions of the MEP pathway gene products of H. brasiliensis together with those of Arabidopsis thaliana, and it was found that 1-deoxy-D-xylulose-5-phosphate reductoisomerase, 2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase, and 2-C-methyl-D-erythritol 2,4-cyclodiphosphate synthase of H. brasiliensis were functionally active in the E. coli mutants. Gene expression analysis revealed that the expression level of the HbDXS2 gene in latex was relatively high as compared to those of other MEP pathway genes. However, a feeding experiment with [1-(13)C] 1-deoxy-D-xylulose triacetate, an intermediate derivative of the MEP pathway, indicated that the MEP pathway is not involved in rubber biosynthesis, but is involved in carotenoids biosynthesis in H. brasiliensis. PMID:18997428

Sando, Tomoki; Takeno, Shinya; Watanabe, Norie; Okumoto, Hiroshi; Kuzuyama, Tomohisa; Yamashita, Atsushi; Hattori, Masahira; Ogasawara, Naotake; Fukusaki, Eiichiro; Kobayashi, Akio

2008-11-01

265

Biosorption of mercury on magnetically modified yeast cells  

Microsoft Academic Search

Brewer's yeast (bottom yeast, Saccharomyces cerevisiae subsp. uvarum) cells were magnetically modified using water based magnetic fluid stabilized perchloric acid. The magnetically modified yeast cells were characterized by scanning electron microscopy (SEM) and electron spin resonance (ESR). Hg2+ biosorption-desorption properties of magnetically modified yeast cells from synthetic solutions were utilized in batch system. The biosorption process was fast; 80% of

Handan Yavuz; Adil Denizli; Hakan Güngüne?; Mirka Safarikova; Ivo Safarik

2006-01-01

266

Copper Biosorption on Magnetically Modified Yeast Cells Under Magnetic Field  

Microsoft Academic Search

Brewer's yeast (bottom yeast, Saccharomyces cerevisiae subsp. uvarum) cells were magnetically modified using water-based magnetic fluid stabilized perchloric acid. The magnetically modified yeast cells were characterized by scanning electron microscopy (SEM). Cu biosorption properties of magnetically modified yeast cells from synthetic solutions were utilized in a continuous magnetic system. The Cu ion-binding capacity decreased drastically with the increase of the

Lokman Uzun; Necdet Sa?lam; Mirka Safarikova; Ivo Safarik; Adil Denizli

2011-01-01

267

The genetics of aging in the yeast Saccharomyces cerevisiae  

Microsoft Academic Search

The yeastSaccharomyces cerevisiae possesses a finite life span similar in many attributes and implications to that of higher eukaryotes. Here, the measure of the life span is the number of generations or divisions the yeast cell has undergone. The yeast cell is the organism, simplifying many aspects of aging research. Most importantly, the genetics of yeast is highly-developed and readily

S. Michal Jazwinski

1993-01-01

268

A Caspase-Related Protease Regulates Apoptosis in Yeast  

Microsoft Academic Search

Yeast can undergo cell death accompanied by cellular markers of apoptosis. However, orthologs of classical mammalian apoptosis regulators appeared to be missing from the yeast genome, challenging a common mechanism of yeast and mammalian apoptosis. Here we investigate Yor197w, a yeast protein with structural homology to mammalian caspases, and demonstrate caspase-like processing of the protein. Hydrogen peroxide treatment induces apoptosis

Frank Madeo; Eva Herker; Corinna Maldener; Silke Wissing; Stephan Lächelt; Mark Herlan; Markus Fehr; Kirsten Lauber; Stephan J Sigrist; Sebastian Wesselborg; Kai-Uwe Fröhlich

2002-01-01

269

The wine and beer yeast Dekkera bruxellensis.  

PubMed

Recently, the non-conventional yeast Dekkera bruxellensis has been gaining more and more attention in the food industry and academic research. This yeast species is a distant relative of Saccharomyces cerevisiae and is especially known for two important characteristics: on the one hand, it is considered to be one of the main spoilage organisms in the wine and bioethanol industry; on the other hand, it is 'indispensable' as a contributor to the flavour profile of Belgium lambic and gueuze beers. Additionally, it adds to the characteristic aromatic properties of some red wines. Recently this yeast has also become a model for the study of yeast evolution. In this review we focus on the recently developed molecular and genetic tools, such as complete genome sequencing and transformation, to study and manipulate this yeast. We also focus on the areas that are particularly well explored in this yeast, such as the synthesis of off-flavours, yeast detection methods, carbon metabolism and evolutionary history. PMID:24932634

Schifferdecker, Anna Judith; Dashko, Sofia; Ishchuk, Olena P; Piškur, Jure

2014-09-01

270

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

271

Optical Tweezing of Yeast Cells  

NASA Astrophysics Data System (ADS)

Optical Tweezers is a powerful technique that aids in understanding and applying the unique principles of photonics, optical physics, and basic cell biology. The experiments presented involve using HeNe lasers (632.8 nm) to trap spherical and ovular shaped objects in a solution. Polystyrene spheres, six micrometers in diameter, were trapped and moved with the laser to calibrate our system. The spheres were submerged in a Sodium Phosphate buffer solution to prevent sticking. Saccharomyces cerevisae, better known as yeast, was grown in a glucose rich environment to reach sizes of four to nine micrometers. Our optical tweezers captured and moved these cells under the operators command. A two laser system was utilized to control two cells simultaneously and attempt the splitting of cells. )

Gilroy, Kyle; Ochoa, Romulo

2010-02-01

272

Structural and phylogenetic analysis of Pto-type disease resistance gene candidates in Hevea brasiliensis.  

PubMed

The tomato Pto gene encodes a serine/threonine kinase (STK) whose molecular characterization has provided valuable insights into the disease resistance mechanism of tomato. Therefore, Pto is considered as a promising candidate for engineering broad-spectrum pathogen resistance in this crop. In this study, a pair of degenerate primers based on conserved subdomains of plant STKs similar to the tomato Pto protein was used to amplify similar sequences in a hevea cultivar (Hevea brasiliensis Muell. Arg). A fragment of ~550 bp was amplified, cloned, and sequenced. The sequence analysis of several clones revealed 12 distinct sequences highly similar to STKs. Based on their significant similarity with the tomato Pto protein (BLASTX E value<3e-53), seven sequences were classified as Pto resistance gene candidates (Pto-RGCs). Multiple sequence alignment of the hevea Pto-RGC products revealed that these sequences contain several conserved subdomains present in most STKs, as well as several conserved residues that are crucial for Pto function. Moreover, phylogenetic analysis showed that the hevea Pto-RGCs clustered with Pto, suggesting a common evolutionary origin with this resistance gene. The Pto-RGCs isolated in this study represent a valuable sequence resource that could assist in the development of disease resistance in hevea. PMID:25036179

Zhai, W; Zhao, Y; Zhang, L X; Li, X J

2014-01-01

273

Relationship between latex yield of Hevea brasiliensis and antecedent environmental parameters  

NASA Astrophysics Data System (ADS)

A study on the relationship between latex yield and antecedent environmental data was undertaken for five clones (RRII203, RRII118, RRIM600, RRII105 and GT1) of Hevea brasiliensis (rubber) in Agartala, northeast India, a region in which rubber is not traditionally cultivated. The explained variance for the regression equations based on parameters determined on the day of tapping and up to 3 days prior to it, varied from 72% to 37% during the NWT period and 94 83% during the WT period. Soil moisture storage, 1 and 3 days prior to tapping, was found to be the primary parameter affecting yield for the NWT and WT periods, respectively. It was observed that the clone RRII105, with a comparatively lower yield to that of RRIM600, was more susceptible to daily WD conditions during the non-winter season. RRIM600 and RRII105 being high-yielding clones were also found to be fairly dependent on the AT of the day prior to tapping. The mean lag period correlation of this parameter with yield was also found to be higher during the WT period than during the NWT period. As a whole, the mean lag period based on prior measurements of environmental variables showed optimum correlation with yield at 15 20 days prior to the day of tapping. The study also confirms that varied responses of yield with environmental factors in this non-traditional region of rubber cultivation depend on clonal character.

Raj, Shammi; Das, Gitali; Pothen, Jacob; Dey, Sushil Kumar

2005-01-01

274

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

275

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

276

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

277

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

278

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

PubMed

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

Chanwun, Thitikorn; Muhamad, Nisaporn; Chirapongsatonkul, Nion; Churngchow, Nunta

2013-01-01

279

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

280

Heterologous expression and characterization of processing ?-glucosidase I from Aspergillus brasiliensis ATCC 9642.  

PubMed

A gene for processing ?-glucosidase I from a filamentous fungus, Aspergillus brasiliensis (formerly called Aspergillus niger) ATCC 9642 was cloned and fused to a glutathione S-transferase tag. The active construct with the highest production level was a truncation mutant deleting the first 16 residues of the hydrophobic N-terminal domain. This fusion enzyme hydrolyzed pyridylaminated (PA-) oligosaccharides Glc(3)Man(9)GlcNAc(2)-PA and Glc(3)Man(4)-PA and the products were identified as Glc(2)Man(9)GlcNAc(2)-PA and Glc(2)Man(4)-PA, respectively. Saturation curves were obtained for both Glc(3)Man(9)GlcNAc(2)-PA and Glc(3)Man(4)-PA, and the K (m) values for both substrates were estimated in the micromolar range. When 1 ?M Glc(3)Man(4)-PA was used as a substrate, the inhibitors kojibiose and 1-deoxynojirimycin had similar effects on the enzyme; at 20 ?M concentration, both inhibitors reduced activity by 50%. PMID:22020441

Miyazaki, Takatsugu; Matsumoto, Yuji; Matsuda, Kana; Kurakata, Yuma; Matsuo, Ichiro; Ito, Yukishige; Nishikawa, Atsushi; Tonozuka, Takashi

2011-12-01

281

Rubber Elongation Factor (REF), a Major Allergen Component in Hevea brasiliensis Latex Has Amyloid Properties  

PubMed Central

REF (Hevb1) and SRPP (Hevb3) are two major components of Hevea brasiliensis latex, well known for their allergenic properties. They are obviously taking part in the biosynthesis of natural rubber, but their exact function is still unclear. They could be involved in defense/stress mechanisms after tapping or directly acting on the isoprenoid biosynthetic pathway. The structure of these two proteins is still not described. In this work, it was discovered that REF has amyloid properties, contrary to SRPP. We investigated their structure by CD, TEM, ATR-FTIR and WAXS and neatly showed the presence of ?-sheet organized aggregates for REF, whereas SRPP mainly fold as a helical protein. Both proteins are highly hydrophobic but differ in their interaction with lipid monolayers used to mimic the monomembrane surrounding the rubber particles. Ellipsometry experiments showed that REF seems to penetrate deeply into the monolayer and SRPP only binds to the lipid surface. These results could therefore clarify the role of these two paralogous proteins in latex production, either in the coagulation of natural rubber or in stress-related responses. To our knowledge, this is the first report of an amyloid formed from a plant protein. This suggests also the presence of functional amyloid in the plant kingdom. PMID:23133547

Berthelot, Karine; Lecomte, Sophie; Estevez, Yannick; Coulary-Salin, Bénédicte; Bentaleb, Ahmed; Cullin, Christophe; Deffieux, Alain; Peruch, Frédéric

2012-01-01

282

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

283

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

284

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

285

Genetic and epigenetic uniformity of polyembryony derived multiple seedlings of Hevea brasiliensis.  

PubMed

Hevea brasiliensis Muell. Arg (Para rubber tree) is a tropical tree species of Amazonian origin widely cultivated in several parts of the world for natural rubber, a highly priced commodity inevitable for the world rubber industry. Large, tree to tree variation in growth and latex yield among individual plants of high yielding Hevea clones is a common phenomenon observed in mature rubber plantations. The genetic heterogeneity of the seedlings which are used as rootstocks for propagation through budgrafting is considered as a major factor  responsible for this variation. In order to minimize this variation, attempts were made to develop highly uniform rootstock material via an in vitro technique by inducing zygotic polyembryony in Hevea. Immature open pollinated fruits of a high yielding clone RRII 105 were cultured by half ovulo embryo culture technique. Multiple embryos were induced from the 8-10-week-old zygote with a novel combination of gibberellic acid (GA3), kinetin, and zeatin. Plantlets were successfully generated from the multiple embryos and raised in the field post hardening. Screening using genetic and epigenetic molecular markers revealed that the multiple seedlings developed are highly uniform and are of single zygotic origin. Development of plants having genetic and epigenetic uniformity suggests that this technique is ideal for raising uniform rootstock material in Hevea which may significantly reduce intraclonal variations. Moreover, these plants could serve as ideal material for physiological and molecular investigations towards the understanding of  stock-scion interaction process in rubber. PMID:25359186

Karumamkandathil, Rekha; Uthup, Thomas K; Sankaran, Sobha; Unnikrishnan, Divya; Saha, Thakurdas; Nair, Sushamakumari S

2014-10-31

286

Studies on the pathogenesis of actinomycotic mycetoma in animals injected with fractions isolated from Nocardia brasiliensis.  

PubMed Central

In the present study the participation was evaluated of isolated fractions of Nocardia brasiliensis in the genesis of the inflammatory response observed in actinomycotic mycetoma. Subcutaneous injection in mice of a suspension containing a polysaccharide fraction F1 obtained by treating cell walls with sodium hydroxide induced an inflammatory response at the inoculation site which was characterized by a large influx of polymorphonuclear (PMN) and mononuclear (MN) leucocytes between the 2nd and 4th days. On the 8th day, a typical granulomatous reaction was observed involving large numbers of epithelioid cells. Intravenous injection of the lipid extract adsorbed to charcoal particles into mice induced an inflammatory reaction around the particles embolized in the pulmonary microcirculation which was similar to that described above. The kinetics of the inflammatory cell migration was studied by total and differential counts of leukocytes that migrated to the peritoneal cavity of rats inoculated intraperitoneally with the F1 and lipid fractions. Both fractions initially induced intense PMN migration, which was later reduced, with a simultaneous increase in mononuclear cells. The present results demonstrate that a polysaccharide fraction (F1) and the lipid fraction reproduce the fundamental lesion of actinomycotic mycetoma. Images Fig. 1 Fig. 2 PMID:3814496

Ekizlerian, S. M.; Brandão Filho, S. L.; Tincani, I.; Alves, L. M.; Silva, C. L.

1987-01-01

287

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

288

Immunoenzymatic absorption test for serodiagnosis of paracoccidioidomycosis.  

PubMed Central

A sensitive enzyme-linked immunosorbent assay is described for paracoccidioidomycosis serodiagnosis, with antigen represented by filtrates from Paracoccidioides brasiliensis cultures. Cross-reactivities were, however, observed with sera from patients with other mycoses such as histoplasmosis, lobomycosis, cryptococcosis, candidiasis, and sporotrichosis. These cross-reactions did not occur when we used as antigen Yarzabal E2 component prepared by affinity fractionation of the culture filtrates. Specific results could also be obtained with the whole filtrate antigen when sera were absorbed with Histoplasma capsulatum yeast and mycelial components. Besides a very high sensitivity (100% of the 69 cases of paracoccidioidomycosis tested), this assay showed no false-positive results for the 206 non-paracoccidioidomycosis sera studied, including those from patients with other mycotic diseases. Images PMID:6746881

Mendes-Giannini, M J; Camargo, M E; Lacaz, C S; Ferreira, A W

1984-01-01

289

Yeast and yeast-like diversity in the southernmost glacier of Europe (Calderone Glacier, Apennines, Italy).  

PubMed

The present study reports the characterization of psychrophilic yeast and yeast-like diversity in cold habitats (superficial and deep sediments, ice cores and meltwaters) of the Calderone Glacier (Italy), which is the southernmost glacier in Europe. After incubation at 4 and 20 degrees C, sediments contained about 10(2)-10(3) CFU of yeasts g(-1). The number of viable yeast cells in ice and meltwaters was several orders of magnitude lower. The concomitant presence of viable bacteria and filamentous fungi has also been observed. In all, 257 yeast strains were isolated and identified by 26S rRNA gene D1/D2 and internal transcribed spacers (1 and 2) sequencing as belonging to 28 ascomycetous and basidiomycetous species of 11 genera (Candida, Cystofilobasidium, Cryptococcus, Dioszegia, Erythrobasidium, Guehomyces, Mastigobasidium, Mrakia, Mrakiella, Rhodotorula and Sporobolomyces). Among them, the species Cryptococcus gastricus accounted for almost 40% of the total isolates. In addition, 12 strains were identified as belonging to the yeast-like species Aureobasidium pullulans and Exophiala dermatitidis, whereas 15 strains, presumably belonging to new species, yet to be described, were also isolated. Results herein reported indicate that the Calderone Glacier, although currently considered a vanishing ice body due to the ongoing global-warming phenomenon, still harbors viable psychrophilic yeast populations. Differences of yeast and yeast-like diversity between the glacier under study and other worldwide cold habitats are also discussed. PMID:20402775

Branda, Eva; Turchetti, Benedetta; Diolaiuti, Guglielmina; Pecci, Massimo; Smiraglia, Claudio; Buzzini, Pietro

2010-06-01

290

[Regulation of gene expression in methylotrophic yeasts].  

PubMed

Methylotrophic yeasts are unique eukaryotic organisms, that can metabolize toxic one-carbon substrate, methyl alcohol or methanol. About 50 species of methylotrophic yeasts is known, among them 4 species are the best studied: Pichia methanolica, Hansenula polymorpha, Pichia pastoris i Candida boidinii. These organisms, especially P. pastoris i H. polymorpha appeared to be very perspective overproducers of heterologous proteins and nowadays are used for industrial production of some of them. In this review, we provide information on the organization of the genome, mechanisms of regulation of gene expression and the use of strong promoters of these yeast species to construct the producers of heterologous proteins. In more details, we analyze genetic control of carbon and nitrogen catabolic repression in H. polymorpha and also the identification of metabolites inducing catabolite repression or peroxisome selective autophagy in the medium with ethanol in the Pichia methanolica yeast. PMID:23821948

Grabek-Lejko, Dorota; Sibirny, Vladimir; Sibirny, Andriy

2013-01-01

291

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

292

Yeasts in ensiled high-moisture corn.  

PubMed

A total of 1,365 yeasts were selected from ensiled high-moisture corn at various stages in the ensiling process to determine the sequence and relative numbers of yeast species. The yeast species most frequently isolated from freshly harvested corn were Candida parapsilosis and C. intermedia; these two species were isolated infrequently after the third week of storage. Species of yeasts that predominate after the 12th day of storage were Hansenula anomala (66% of the isolates studied) and C. krusei (26% of the isolates studied). The preponderance of H. anomala and C. krusei in ensiled corn is believed to be associated with the ability of these two species to assimilate lactic acid. PMID:5914494

Burmeister, H R; Hartman, P A

1966-01-01

293

Functional analysis of the yeast genome  

Microsoft Academic Search

.   Just as Saccharomyces cerevisiae itself provides a model for so many processes essential to eukaryotic life, we anticipate that the methods and the mindset\\u000a that have moved yeast biological research \\

Petra Ross-Macdonald

2000-01-01

294

ENGINEERING THE BIOSYNTHESIS OF STYRENE IN YEAST  

EPA Science Inventory

The strategy pursued was to insert genes for phenylalanine ammonia lysase (pal) and phenolic acid decarboxylase (pad) into the yeast that would convert phenylalanine to styrene through a cinnamic acid intermediate. ...

295

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.

296

Comparative functional genomics of the fission yeasts.  

PubMed

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 annotation of these genomes identified a near extinction of transposons and the associated innovation of transposon-free centromeres. Expression analysis established that meiotic genes are subject to antisense transcription during vegetative growth, which suggests a mechanism for their tight regulation. In addition, trans-acting regulators control new genes within the context of expanded functional modules for meiosis and stress response. Differences in gene content and regulation also explain why, unlike the budding yeast of Saccharomycotina, fission yeasts cannot use ethanol as a primary carbon source. These analyses elucidate the genome structure and gene regulation of fission yeast and provide tools for investigation across the Schizosaccharomyces clade. PMID:21511999

Rhind, Nicholas; Chen, Zehua; Yassour, Moran; Thompson, Dawn A; Haas, Brian J; Habib, Naomi; Wapinski, Ilan; Roy, Sushmita; Lin, Michael F; Heiman, David I; Young, Sarah K; Furuya, Kanji; Guo, Yabin; Pidoux, Alison; Chen, Huei Mei; Robbertse, Barbara; Goldberg, Jonathan M; Aoki, Keita; Bayne, Elizabeth H; Berlin, Aaron M; Desjardins, Christopher A; Dobbs, Edward; Dukaj, Livio; Fan, Lin; FitzGerald, Michael G; French, Courtney; Gujja, Sharvari; Hansen, Klavs; Keifenheim, Dan; Levin, Joshua Z; Mosher, Rebecca A; Müller, Carolin A; Pfiffner, Jenna; Priest, Margaret; Russ, Carsten; Smialowska, Agata; Swoboda, Peter; Sykes, Sean M; Vaughn, Matthew; Vengrova, Sonya; Yoder, Ryan; Zeng, Qiandong; Allshire, Robin; Baulcombe, David; Birren, Bruce W; Brown, William; Ekwall, Karl; Kellis, Manolis; Leatherwood, Janet; Levin, Henry; Margalit, Hanah; Martienssen, Rob; Nieduszynski, Conrad A; Spatafora, Joseph W; Friedman, Nir; Dalgaard, Jacob Z; Baumann, Peter; Niki, Hironori; Regev, Aviv; Nusbaum, Chad

2011-05-20

297

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

298

Macromolecular synthesis by yeasts under frozen conditions  

E-print Network

by the protein synthesis inhibitor cycloheximide. Experi- ments at -5°C under frozen and liquid conditionsMacromolecular synthesis by yeasts under frozen conditions Pierre Amato,* Shawn Doyle and Brent C

Christner, Brent C.

299

Monitoring Air Quality with Leaf Yeasts.  

ERIC Educational Resources Information Center

Proposes that leaf yeast serve as quick, inexpensive, and effective techniques for monitoring air quality. Outlines procedures and provides suggestions for data analysis. Includes results from sample school groups who employed this technique. (ML)

Richardson, D. H. S.; And Others

1985-01-01

300

Multidrug resistant yeasts in synanthropic wild birds  

PubMed Central

Background The aim of this study was to investigate the presence of multidrug resistant yeasts in the faeces of synanthropic wild birds from the Bangsar suburb of Kuala Lumpur. Methods Species characterisations of yeast isolates and determinations of antimycotic susceptibility profiles were undertaken using the commercial characterization kit, Integral System Yeasts Plus (Liofilchem, Italy). Results Fourteen species of yeasts were detected in the bird faecal samples.Candida albicans was present in 28.89% of bird faecal samples, Candida krusei (13.33%), Candida tropicalis (4.44%), Candida glabrata (4.44%), Candida parapsilosis (2.22%), Candida lambica (2.22%), Candida stellatoidea (2.22%), Candida rugosa (2.22%) and Candida lusitaniae (2.22%). Amongst the non-candidal yeast isolates, Cryptococcus laurentii was present in 6.67% of bird faecal samples, Cryptococcus uniguttulatus (4.44%), Saccharomyces cerevisiae (4.44%), Trichosporon pullulans (2.22%), Trichosporon pullulans/Cryptococcus albidus (8.89%) and Rhodotorula rubra/Rhodotorula glutinis (4.44%). Of the isolated yeasts, 18.1% (or 26/144) were found to be resistant to all 11 antimycotic agents they were tested against i.e. Nystatin, Amphotericin B, Flucytosine, Econazole, Ketoconazole, Clotrimazole, Miconazole, Itraconazole, Voriconazole, Fluconazole 16 and Fluconazole 64. 45.8% (or 66/144) of the bird faecal yeast isolates were resistant to four or more of the 11 antimycotic agents they were tested against. Conclusions This finding is of public health significance as these synanthropic wild birds may be reservoirs for transmission of drug resistant yeast infections to humans. PMID:20307325

2010-01-01

301

How to Make Yeast Cells Thrive  

NSDL National Science Digital Library

Students set up and run the experiments they designed in the Population Growth in Yeasts associated lesson, using simple yeast-molasses cultures in test tubes. Population growth is indicated by the amount of respiration occurring in the cultures, which in turn is indicated by the growth of carbon dioxide bubbles trapped within the culture tubes. Using this method, students test for a variety of environmental influences, such as temperature, food supply and pH.

Engineering K-Phd Program

302

The secretory pathway: exploring yeast diversity.  

PubMed

Protein secretion is an essential process for living organisms. In eukaryotes, this encompasses numerous steps mediated by several hundred cellular proteins. The core functions of translocation through the endoplasmic reticulum membrane, primary glycosylation, folding and quality control, and vesicle-mediated secretion are similar from yeasts to higher eukaryotes. However, recent research has revealed significant functional differences between yeasts and mammalian cells, and even among diverse yeast species. This review provides a current overview of the canonical protein secretion pathway in the model yeast Saccharomyces cerevisiae, highlighting differences to mammalian cells as well as currently unresolved questions, and provides a genomic comparison of the S. cerevisiae pathway to seven other yeast species where secretion has been investigated due to their attraction as protein production platforms, or for their relevance as pathogens. The analysis of Candida albicans, Candida glabrata, Kluyveromyces lactis, Pichia pastoris, Hansenula polymorpha, Yarrowia lipolytica, and Schizosaccharomyces pombe reveals that many - but not all - secretion steps are more redundant in S. cerevisiae due to duplicated genes, while some processes are even absent in this model yeast. Recent research obviates that even where homologous genes are present, small differences in protein sequence and/or differences in the regulation of gene expression may lead to quite different protein secretion phenotypes. PMID:23480475

Delic, Marizela; Valli, Minoska; Graf, Alexandra B; Pfeffer, Martin; Mattanovich, Diethard; Gasser, Brigitte

2013-11-01

303

Attempts to detect lycopersene formation in yeast  

PubMed Central

1. ?-Ionone vapour has been shown to cause an increase in the more saturated carotenes and a decrease in the less saturated carotenes of Rhodotorula glutinis. Lycopersene (dihydrophytoene) has been proposed as a precursor to phytoene. Attempts were made to isolate lycopersene from ?-ionone-treated cultures of R. glutinis. 2. Large samples of ?-ionone-treated cultures were examined for the presence of lycopersene. Spots were detected on silicic acid plates that could not be differentiated from synthetic lycopersene on the basis of column and thin-layer chromatographic separations and staining techniques. The lycopersene-like substance could be obtained from non-treated pigmented yeast as well as baker's yeast. 3. An extraction of bacterial-grade yeast extract also yielded a lycopersene-like substance. The extracts of R. glutinis cells cultured on media not containing yeast extract did not contain the lycopersene-like compound. 4. No significant carbon was incorporated into the lycopersene zone from 14C-labelled mevalonate, acetate and glucose by R. glutinis and baker's yeast. 5. These results indicate that compounds may exist with chromatographic properties similar to lycopersene, but that lycopersene could not be detected in either a pigmented or a non-pigmented yeast. PMID:5753091

Scharf, S. S.; Simpson, K. L.

1968-01-01

304

The growth of solar radiated yeast  

NASA Technical Reports Server (NTRS)

This researcher plans to determine if solar radiation affects the growth of yeast. The irradiated yeast was obtained from a sample exposed in space during a Space Shuttle flight of September 9-20, 1994. Further, the control groups were held at: (1) Goddard Space Flight Center (GSFC) in Greenbelt, Maryland; and (2) South Dakota School of Mines and Technology. The procedure used was based on the fact that yeast is most often used in consumable baked goods. Therefore, the yeast was incorporated into a basic Betty Crocker bread recipe. Data was collected by placing measured amounts of dough into sample containers with fifteen minute growth in height measurements collected and recorded. This researcher assumed the viability of yeast to be relative to its ability to produce carbon dioxide gas and cause the dough to rise. As all ingredients and surroundings were equal, this researcher assumed the yeast will produce the only significant difference in data collected. This researcher noted the approximate use date on all sample packages to be prior to arrival and experiment date. All dates equal, it was then assumed each would act in a similar manner of response. This assumption will allow for equally correct data collection.

Kraft, Tyrone

1995-01-01

305

The growth of solar radiated yeast  

SciTech Connect

This researcher plans to determine if solar radiation affects the growth of yeast. The irradiated yeast was obtained from a sample exposed in space during a Space Shuttle flight of September 9-20, 1994. Further, the control groups were held at: (1) Goddard Space Flight Center (GSFC) in Greenbelt, Maryland; and (2) South Dakota School of Mines and Technology. The procedure used was based on the fact that yeast is most often used in consumable baked goods. Therefore, the yeast was incorporated into a basic Betty Crocker bread recipe. Data was collected by placing measured amounts of dough into sample containers with fifteen minute growth in height measurements collected and recorded. This researcher assumed the viability of yeast to be relative to its ability to produce carbon dioxide gas and cause the dough to rise. As all ingredients and surroundings were equal, this researcher assumed the yeast will produce the only significant difference in data collected. This researcher noted the approximate use date on all sample packages to be prior to arrival and experiment date. All dates equal, it was then assumed each would act in a similar manner of response. This assumption will allow for equally correct data collection.

Kraft, T.

1995-09-01

306

The role of complement in innate, adaptive and eosinophil-dependent immunity to the nematode Nippostrongylus brasiliensis.  

PubMed

Complement may be important for immunity to infection with parasitic helminths, by promoting the recruitment of leukocytes to infected tissues and by modulating the function of cytotoxic effector leukocytes. However, the importance of complement in vivo during helminth infection is poorly understood. In this study, mice lacking classical (C1q-deficient), alternative (factor B-deficient) or all pathways of complement activation (C3-deficient) were used to assess the role of complement in immunity to the nematode Nippostrongylus brasiliensis. Double-mutant complement-deficient/IL-5 transgenic (Tg) mice were used to determine if complement is required for the strong eosinophil-dependent resistance to this parasite. Complement activation on larvae (C3 deposition), extracellular eosinophil peroxidase activity, larval aggregation and eosinophil recruitment to the skin 30 min post-injection (p.i.) of larvae were reduced in factor B-deficient mice. Inhibition of the C5a receptor with the antagonist PMX53 impaired eosinophil and neutrophil recruitment to the skin. C3 deposition on larvae was minimal by 150 min p.i. and at this time cell adherence, larval aggregation, eosinophil recruitment and degranulation were complement-independent. Factor B and C3 deficiency were associated with higher lung larval burdens in primary infections. Complement-deficient/IL-5 Tg mice were highly resistant to N. brasiliensis, suggesting that eosinophils can limit infection in a complement-independent manner. Potent secondary immunity was similarly complement-independent. In conclusion, although the alternative pathway is important for parasite recognition and leukocyte recruitment early in N. brasiliensis infections, the parasite soon becomes resistant to complement and other factors can compensate to promote eosinophil-dependent immunity. PMID:17675237

Giacomin, Paul R; Gordon, David L; Botto, Marina; Daha, Mohamed R; Sanderson, Sam D; Taylor, Stephen M; Dent, Lindsay A

2008-01-01

307

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

308

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

309

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

310

Effects of whole-body irradiation on the development of Nippostrongylus brasiliensis (Travassos, 1914) Lane, 1923, in rats  

E-print Network

occasionally penetrated via hair follicles. Development of N. brasiliensis larvae in the skin of the rat is characterized by an initial lag-phase resulting in a decrease in total length followed by an increase in length near the end of their stay... cent of the fourth stage larvae had completed their migration from the lungs to the intestine via the trachea, esophagus, through the stomach to the small intestine. Very few larvae remained in the lungs after the third day of infection (Haley 1958a...

Gatlin, Gilbert Wayne

1966-01-01

311

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

E-print Network

Yeast through the ages: A statistical analysis of genetic changes in aging yeast A. Wise J. Hardin into the roles of specific genes and the associated changes across experimental conditions (e.g., aging, mutation sense of the experiment and thereby advance genetic, biological, and medical research. Likewise

Hardin, Jo

312

Yeast cell-wall synthesis  

PubMed Central

1. A study of wall synthesis has been made by following the incorporation of radioactive glucose and threonine into the cytoplasm and wall of yeast. 2. Both glucose and threonine are incorporated into a mannan glycopeptide. The glucose is also synthesized into a structural glucan of the wall. 3. The mannan glycopeptide contains high-molecular-weight mannan and low-molecular-weight mannose and oligosaccharide units composed of mannose. Both types of carbohydrate are attached to the peptide. The extent of radioactive incorporation into these different carbohydrate constituents of the glycopeptide remained constant during a pulse-chase experiment. No evidence of a sequential synthesis of oligosaccharides and high-molecular-weight mannan was obtained. 4. Cycloheximide inhibits the incorporation of threonine into the wall but only partially inhibits the incorporation of glucose. Thus not all the polysaccharide deposited into the wall is dependent on a simultaneous peptide synthesis and incorporation. 5. Protoplasts grown in an iso-osmotic medium secreted a mannan polymer that was probably a glycopeptide. PMID:5378380

Sentandreu, R.; Northcote, D. H.

1969-01-01

313

The capacity for paracellular absorption in the insectivorous bat Tadarida brasiliensis.  

PubMed

Water-soluble nutrients are absorbed by the small intestine via transcellular and paracellular processes. The capacity for paracellular absorption seems greater in fliers than in nonfliers, although that conclusion rests mainly on a comparison of flying birds and nonflying mammals because only two frugivorous bat species have been studied. Furthermore, the bats studied so far were relatively large (>85 g, compared with most bat species which are <20 g) and were not insectivores (like about 70 % of bat species). We studied the small (11 g) insectivorous bat Tadarida brasiliensis and tested the prediction that the capacity for paracellular absorption would be as high as in the other bat and avian species studied so far, well above that in terrestrial, nonflying mammals. Using standard pharmacokinetic technique, we measured the extent of absorption (fractional absorption = f) of inert carbohydrate probes: L-arabinose (MM = 150.13) absorbed exclusively by paracellular route and 3OMD-glucose (MM = 194) absorbed both paracellularly and transcellularly. As predicted, the capacity of paracellular absorption in this insectivorous bat was high (L-arabinose f = 1.03 ± 0.14) as in other frugivorous bats and small birds. Absorption of 3OMD-glucose was also complete (f = 1.09 ± 0.17), but >80 % was accounted for by paracellular absorption. We conclude that passive paracellular absorption of molecules of the size of amino acids and glucose is extensive in this bat and, generally in bats, significantly higher than that in nonflying mammals, although the exact extent can be somewhat lower or higher depending on molecule size, polarity and charge. PMID:22872186

Fasulo, Verónica; Zhang, ZhiQiang; Chediack, Juan G; Cid, Fabricio D; Karasov, William H; Caviedes-Vidal, Enrique

2013-02-01

314

Characterization and cytotoxic activity of sulfated derivatives of polysaccharides from Agaricus brasiliensis  

PubMed Central

Agaricus brasiliensis cell-wall polysaccharides isolated from fruiting body (FR) and mycelium (MI) and their respective sulfated derivatives (FR-S and MI-S) were chemically characterized using elemental analysis, TLC, FT-IR, NMR, HPLC, and thermal analysis. Cytotoxic activity was evaluated against A549 tumor cells by MTT and sulforhodamine assays. The average molecular weight (Mw) of FR and MI was estimated to be 609 and 310 kDa, respectively. FR-S (127 kDa) and MI-S (86 kDa) had lower Mw, probably due to hydrolysis occurred during the sulfation reaction. FR-S and MI-S presented ~14 % sulfur content in elemental analysis. Sulfation of samples was characterized by the appearance of two new absorption bands at 1253 and 810 cm?1 in the infrared spectra, related to S=O and C-S-O sulfate groups, respectively. Through 1H and 13C NMR analysis FR-S was characterized as a (1?6)-(1?3)-?-D-glucan fully sulfated at C-4 and C-6 terminal and partially sulfated at C-6 of (1?3)-?-D-glucan moiety. MI-S was shown to be a (1?3)-?-D-gluco-(1?2)-?-D-mannan, partially sulfated at C-2, C-3, C-4, and C-6, and fully sulfated at C-6 of the terminal residues. The combination of high degree of sulfation and low molecular weight was correlated with the increased cytotoxic activity (48 h of treatment) of both FR-S (EC50=605.6 ?g/mL) and MI-S (EC50=342.1 ?g/mL) compared to the non-sulfated polysaccharides FR and MI (EC50>1500 ?g/mL). PMID:23511057

Cardozo, F. T. G. S.; Camelini, C. M.; Cordeiro, M. N. S.; Mascarello, A.; Malagoli, B. G.; Larsen, I.; Rossi, M. J.; Nunes, R. J.; Braga, F. C.; Brandt, C.R.; Simões, C. M. O.

2014-01-01

315

Physiological and molecular responses to variation of light intensity in rubber Tree (Hevea brasiliensis Muell. Arg.).  

PubMed

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

316

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

317

The Latex of Hevea brasiliensis Contains High Levels of Both Chitinases and Chitinases/Lysozymes 1  

PubMed Central

The latex of the commercial rubber tree, Hevea brasiliensis, was fractionated by ultracentrifugation as described by G. F. J. Moir ([1959] Nature 184: 1626-1628) into a top layer of rubber particles, a cleared cytoplasm, and a pellet that contains primarily specialized vacuoles known as lutoids. The proteins in each fraction were resolved by two-dimensional gel electrophoresis. Both the pellet fraction and cleared cytoplasm contained large amounts of relatively few proteins, suggesting that laticifers serve a very specialized function in the plant. More than 75% of the total soluble protein in latex was found in the pellet fraction. Twenty-five percent of the protein in the pellet was identified as chitinases/lysozymes, which are capable of degrading the chitin component of fungal cell walls and the peptidoglycan component of bacterial cell walls. Both the chitinase and lysozyme activities were localized exclusively in the pellet or lutoid fraction. The chitinases/lysozymes were resolved into acidic and basic classes of proteins and further purified. An acidic protein (molecular mass 25.5 kD) represented 20% of the chitinase activity in latex; this protein lacked the low level of lysozyme activity that is associated with many plant chitinases. Six basic proteins, having both chitinase and lysozyme activities in various ratios and molecular mass of 27.5 or 26 kD, were resolved. Two of the basic proteins had very high lysozyme specific activities which were comparable to the specific activities reported for animal lysozymes. Like animal lysozymes, but unlike previously characterized plant chitinases/lysozymes, these basic chitinases/lysozymes were also capable of completely lysing or clearing suspensions of bacterial cell walls. These results suggest that laticifers may serve a defensive role in the plant. Images Figure 2 Figure 5 PMID:16668007

Martin, Melinda N.

1991-01-01

318

Evidence for yeast autophagy during simulation of sparkling wine aging: a reappraisal of the mechanism of yeast autolysis in wine.  

PubMed

Yeast autolysis is the source of several molecules responsible for the quality of wines aged in contact with yeast cells. However, the mechanisms of yeast autolysis during wine aging are not completely understood. All descriptions of yeast autolysis in enological conditions emphasize the disturbance of cell organization as the starting event in the internal digestion of the cell, while no reference to autophagy is found in wine-related literature. By using yeast mutants defective in the autophagic or the Cvt pathways we have demonstrated that autophagy does take place in wine production conditions. This finding has implications for the genetic improvement of yeasts for accelerated autolysis. PMID:15801807

Cebollero, Eduardo; Carrascosa, Alfonso V; Gonzalez, Ramon

2005-01-01

319

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

320

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

321

Effects of light intensity on the distribution of anthocyanins in Kalanchoe brasiliensis Camb. and Kalanchoe pinnata (Lamk.) Pers.  

PubMed

This paper compares two medicinal species of Kalanchoe, which are often used interchangeably by the population, regarding the distribution of anthocyanins under the influence of four luminosity levels for 6 months. For the morphoanatomical analysis, the 6th stem node of each plant was sectioned. Usual histochemical tests revealed the presence of anthocyanins by cross sections of the stems, petioles and leaf blades. The petioles and leaf blades were submitted to the extraction with acidified methanol, and the anthocyanins were quantified by spectrophotometric readings. At the macroscopic level, it was noticed for both species a higher presence of anthocyanins in stems and petioles of plants under full sunlight. The microscopy of K. brasiliensis stems evidenced the deposition of anthocyanins in the subjacent tissue to the epidermis and cortex, which increased with light intensity. In K. pinnata a subepidermal collenchyma was observed, which interfered in the visualization of anthocyanins. In petioles and leaf blades of K. brasiliensis the deposition of anthocyanins was peripheral, and in K. pinnata it was also throughout the cortex. The quantification of anthocyanins in petioles showed in 70% of light higher averages than in 25%, but in leaf blades there were no significant results. This study contributes to the pharmacognosy of Kalanchoe and it is sustained by the description of flavonoids as biological markers of the genus. PMID:22441611

Cruz, Bruna P; Chedier, Luciana M; Peixoto, Paulo H P; Fabri, Rodrigo L; Pimenta, Daniel S

2012-03-01

322

Whole-Transcriptome Survey of the Putative ATP-Binding Cassette (ABC) Transporter Family Genes in the Latex-Producing Laticifers of Hevea brasiliensis.  

PubMed

The ATP-binding cassette (ABC) proteins or transporters constitute a large protein family in plants and are involved in many different cellular functions and processes, including solute transportation, channel regulation and molecular switches, etc. Through transcriptome sequencing, a transcriptome-wide survey and expression analysis of the ABC protein genes were carried out using the laticiferous latex from Hevea brasiliensis (rubber tree). A total of 46 putative ABC family proteins were identified in the H. brasiliensis latex. These consisted of 12 'full-size', 21 'half-size' and 13 other putative ABC proteins, and all of them showed strong conservation with their Arabidopsis thaliana counterparts. This study indicated that all eight plant ABC protein paralog subfamilies were identified in the H. brasiliensis latex, of which ABCB, ABCG and ABCI were the most abundant. Real-time quantitative reverse transcription-polymerase chain reaction assays demonstrated that gene expression of several latex ABC proteins was regulated by ethylene, jasmonic acid or bark tapping (a wound stress) stimulation, and that HbABCB15, HbABCB19, HbABCD1 and HbABCG21 responded most significantly of all to the abiotic stresses. The identification and expression analysis of the latex ABC family proteins could facilitate further investigation into their physiological involvement in latex metabolism and rubber biosynthesis by H. brasiliensis. PMID:25615936

Zhiyi, Nie; Guijuan, Kang; Yu, Li; Longjun, Dai; Rizhong, Zeng

2015-01-01

323

Whole-Transcriptome Survey of the Putative ATP-Binding Cassette (ABC) Transporter Family Genes in the Latex-Producing Laticifers of Hevea brasiliensis  

PubMed Central

The ATP-binding cassette (ABC) proteins or transporters constitute a large protein family in plants and are involved in many different cellular functions and processes, including solute transportation, channel regulation and molecular switches, etc. Through transcriptome sequencing, a transcriptome-wide survey and expression analysis of the ABC protein genes were carried out using the laticiferous latex from Hevea brasiliensis (rubber tree). A total of 46 putative ABC family proteins were identified in the H. brasiliensis latex. These consisted of 12 ‘full-size’, 21 ‘half-size’ and 13 other putative ABC proteins, and all of them showed strong conservation with their Arabidopsis thaliana counterparts. This study indicated that all eight plant ABC protein paralog subfamilies were identified in the H. brasiliensis latex, of which ABCB, ABCG and ABCI were the most abundant. Real-time quantitative reverse transcription-polymerase chain reaction assays demonstrated that gene expression of several latex ABC proteins was regulated by ethylene, jasmonic acid or bark tapping (a wound stress) stimulation, and that HbABCB15, HbABCB19, HbABCD1 and HbABCG21 responded most significantly of all to the abiotic stresses. The identification and expression analysis of the latex ABC family proteins could facilitate further investigation into their physiological involvement in latex metabolism and rubber biosynthesis by H. brasiliensis. PMID:25615936

Zhiyi, Nie; Guijuan, Kang; Yu, Li; Longjun, Dai; Rizhong, Zeng

2015-01-01

324

Chapter 6: The genomes of lager yeasts.  

PubMed

Yeasts used in the production of lagers belong to the genus Saccharomyces pastorianus. Species within this genus arose from a natural hybridization event between two yeast species that appear to be closely related to Saccharomyces cerevisiae and Saccharomyces bayanus. The resultant hybrids contain complex allopolyploid genomes and retain genetic characteristics of both parental species. Recent genome analysis using both whole genome sequencing and competitive genomic hybridization techniques has revealed the underlying composition of lager yeasts genomes. There appear to be at least 36 unique chromosomes, many of which are lager specific, resulting from recombination events between the homeologous parental chromosomes. The recombination events are limited to a defined set of genetic loci, which are highly conserved within strains of lager yeasts. In addition to the hybrid chromosomes, several non-reciprocal chromosomal translocations and inversions are also observed. Remarkably, in response to exposure to environmental stresses such as high temperatures and high osmotic pressure, the genomes appear to be highly dynamic and undergo recombination events at defined loci and alterations in the telomeric regions. The ability of environmental stress to alter the structure and composition of the genomes of lager yeasts may point to mechanisms of adaptive evolution in these species. PMID:19729094

Bond, Ursula

2009-01-01

325

Yeasts associated with Sardinian ewe's dairy products.  

PubMed

In the present work, the occurrence of yeasts in different types of typical Sardinian ewe's cheeses (32 samples of pecorino, 32 of caciotta, 40 of feta, 56 of ricotta) was determined. For the strains isolated the following properties were studied: proteolytic and lipolytic activities, the ability to grow at different temperatures, different concentrations of salt, and to assimilate and/or ferment compounds like lactate, citrate, lactose, glucose, galactose, lactic acid. Of 160 samples analysed, 76.2% yielded growth of yeasts. Yeast counts showed a certain variability among the samples. The highest levels were observed in caciotta and feta cheeses. A total of 281 strains belonging to 16 genera and 25 species were identified. In general, Debaryomyces hansenii was the dominant species, representing 28.8% of the total isolates. Other frequently appearing species were Geotrichum candidum, Kluyveromyces lactis and K. marxianus. Other genera encountered were Pichia, Candida, Dekkera, Yarrowia and Rhodotorula. With regard to the biochemical and technological properties of the yeasts, only K. lactis, K. marxianus and Dek. anomala assimilated and fermented lactose, whereas the majority of the species assimilated lactic acid. The assimilation of citrate was a characteristic of D. hansenii, R. rubra and Y. lipolytica. On the whole, the yeasts were weakly proteolytic while lipolytic activity was present in several species. A high percentage of strains showed a certain tolerance to low temperatures while only some strains of D. hansenii and K. lactis were able to grow at a 10% NaCl concentration. PMID:11589560

Cosentino, S; Fadda, M E; Deplano, M; Mulargia, A F; Palmas, F

2001-09-19

326

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; Luizão, R C; do Socorro Barreto da Silva, M; Teixeira, M F; Muniz, E G

1984-01-01

327

Cryosectioning Yeast Communities for Examining Fluorescence Patterns  

PubMed Central

Microbes typically live in communities. The spatial organization of cells within a community is believed to impact the survival and function of the community1. Optical sectioning techniques, including confocal and two-photon microscopy, have proven useful for observing spatial organization of bacterial and archaeal communities2,3. A combination of confocal imaging and physical sectioning of yeast colonies has revealed internal organization of cells4. However, direct optical sectioning using confocal or two-photon microscopy has been only able to reach a few cell layers deep into yeast colonies. This limitation is likely because of strong scattering of light from yeast cells4. Here, we present a method based on fixing and cryosectioning to obtain spatial distribution of fluorescent cells within Saccharomyces cerevisiae communities. We use methanol as the fixative agent to preserve the spatial distribution of cells. Fixed communities are infiltrated with OCT compound, frozen, and cryosectioned in a cryostat. Fluorescence imaging of the sections reveals the internal organization of fluorescent cells within the community. Examples of yeast communities consisting of strains expressing red and green fluorescent proteins demonstrate the potentials of the cryosectioning method to reveal the spatial distribution of fluorescent cells as well as that of gene expression within yeast colonies2,3. Even though our focus has been on Saccharomyces cerevisiae communities, the same method can potentially be applied to examine other microbial communities. PMID:23287845

Momeni, Babak; Shou, Wenying

2012-01-01

328

Mitochondrial membrane lipidome defines yeast longevity  

PubMed Central

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

Burstein, Michelle T.; Bourque, Simon D.; Koupaki, Olivia; Juneau, Mylène; Feldman, Rachel; Iouk, Tatiana; Titorenko, Vladimir I.

2013-01-01

329

Production of alpha-amylase by yeast  

SciTech Connect

The enzyme alpha-amylase confers to an organism the enzymatic activity for the degradation of polyglucosides with alpha-1,4 glycosidic bonds such as starch and glycogen which are among the major storage compounds in plants and animals. Most alpha-amylases are single polypeptides of molecular weights around 50,000 dalton. They are generally found in the digestive tract of animals and in germinating seeds. Among the products released upon enzymatic degradation of polyglucosides maltose, a sugar that can be utilized as carbon source by yeast, is a major constituent. A cDNA segment complementary to mouse salivary amylase messenger RNA has been inserted into the yeast expression vector pMA56 behind the promoter of the gene encoding alcohol dehydrogenase I of yeast. Yeast transformants harboring plasmids with the normal orientation of the promoter and the mouse amylase cDNA gene produce amylase and release the enzyme in free form into the culture medium. Approximately 90% of the amylase activity is found in the medium. Yeast strains carrying MAL allele and transformed with a plasmid which directed the synthesis of mouse alpha-amylase were tested on plates containing starch and in batch fermentations using different high molecular weight sugars and oligosaccharides as carbon source. The results of these experiments will be discussed. (Refs. 21).

Thomse, K.K.

1987-01-01

330

Dissecting the fission yeast regulatory network reveals phase-specific control elements of its cell cycle  

Microsoft Academic Search

BACKGROUND: Fission yeast Schizosaccharomyces pombe and budding yeast Saccharomyces cerevisiae are among the original model organisms in the study of the cell-division cycle. Unlike budding yeast, no large-scale regulatory network has been constructed for fission yeast. It has only been partially characterized. As a result, important regulatory cascades in budding yeast have no known or complete counterpart in fission yeast.

Pierre R Bushel; Nicholas A Heard; Roee Gutman; Liwen Liu; Shyamal D Peddada; Saumyadipta Pyne

2009-01-01

331

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

332

YEASTS FROM THE NORTH SEA AND AMOCO CADIZ OIL  

EPA Science Inventory

The species and densities of yeasts isolated from North Sea waters before and after the production of oil were compared. Debaryomyces hansenii was the predominant species, but after oil production, Candida guillieromondii, a hydrocarbonoclastic yeast, was more commonly isolated a...

333

Contribution of Yeast Models to Neurodegeneration Research  

PubMed Central

As a model organism Saccharomyces cerevisiae has greatly contributed to our understanding of many fundamental aspects of cellular biology in higher eukaryotes. More recently, engineered yeast models developed to study endogenous or heterologous proteins that lay at the root of a given disease have become powerful tools for unraveling the molecular basis of complex human diseases like neurodegeneration. Additionally, with the possibility of performing target-directed large-scale screenings, yeast models have emerged as promising first-line approaches in the discovery process of novel therapeutic opportunities against these pathologies. In this paper, several yeast models that have contributed to the uncovering of the etiology and pathogenesis of several neurodegenerative diseases are described, including the most common forms of neurodegeneration worldwide, Alzheimer's, Parkinson's, and Huntington's diseases. Moreover, the potential input of these cell systems in the development of more effective therapies in neurodegeneration, through the identification of genetic and chemical suppressors, is also addressed. PMID:22910375

Pereira, Clara; Bessa, Cláudia; Soares, Joana; Leão, Mariana; Saraiva, Lucília

2012-01-01

334

Rapid methods for identification of yeasts.  

PubMed Central

Opportunistic infections by yeasts have been implicated as one of the major causes of complications in the compromised patient. Rapid recognition and identification of these yeasts is essential for patient management, but conventional liquid medium methods for completing identification tests are cumbersome and time consuming. Rapid tests have been devised based on modifications of methods commonly used in bacteriology. These rapid methods included tests for carbohydrate and nitrate assimilation, fermentation, and urease production. These were compared with several current methods for accuracy of results, for time to final identification, and for economy of time and reagents. In addition, the usual tests for pseudogerm tube formation, for production of hyphae or pseudohyphae, and for growth temperatures were included. The rapid tests achieved 96% or better accuracy compared with expected results, and 46 species of yeasts were identified in 1 to 2 days compared with the 10 to 14 days required by conventional liquid culture methods. Images PMID:1241586

Huppert, M; Harper, G; Sun, S H; Delanerolle, V

1975-01-01

335

Alcoholic fermentation by 'non-fermentative' yeasts.  

PubMed

All type strains of 'non-fermentative' yeasts, available in the culture collection of the Centraalbureau voor Schimmelcultures, were reinvestigated for their capacity to ferment glucose in the classical Durham tube test. Although visible gas production was absent, nearly all strains produced significant amounts of ethanol under the test conditions. Under conditions of oxygen-limited growth, even strong alcoholic fermentation may occur in a number of yeasts hitherto considered as non-fermentative. Thus, shake-flask cultures of Hansenula nonfermentans and Candida silvae fermented more than half of the available sugar to ethanol. It is concluded that the taxonomic test for fermentation capacity, which relies on detection of gas formation in Durham tubes, is not reliable for a physiological classification of yeasts as fermentative and non-fermentative species. PMID:3333301

van Dijken, J P; van den Bosch, E; Hermans, J J; de Miranda, L R; Scheffers, W A

1986-06-01

336

Yeast Oligo-mediated Genome Engineering (YOGE)  

PubMed Central

High-frequency oligonucleotide-directed recombination engineering (recombineering) has enabled rapid modification of several prokaryotic genomes to date. Here, we present a method for oligonucleotide-mediated recombineering in the model eukaryote and industrial production host S. cerevisiae, which we call Yeast Oligo-mediated Genome Engineering (YOGE). Through a combination of overexpression and knockouts of relevant genes and optimization of transformation and oligonucleotide designs, we achieve high gene modification frequencies at levels that only require screening of dozens of cells. We demonstrate the robustness of our approach in three divergent yeast strains, including those involved in industrial production of bio-based chemicals. Furthermore, YOGE can be iteratively executed via cycling to generate genomic libraries up to 105 individuals at each round for diversity generation. YOGE cycling alone, or in combination with phenotypic selections or endonuclease-based negative genotypic selections, can be used to easily generate modified alleles in yeast populations with high frequencies. PMID:24160921

DiCarlo, JE; Conley, AJ; Penttilä, M; Jäntti, J; Wang, HH; Church, GM

2014-01-01

337

Comparative Functional Genomics of the Fission Yeasts  

PubMed Central

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 annotation of these genomes identified a near extinction of transposons and the associated innovation of transposon-free centromeres. Expression analysis established that meiotic genes are subject to antisense transcription during vegetative growth, suggesting a mechanism for their tight regulation. In addition, trans-acting regulators control new genes within the context of expanded functional modules for meiosis and stress response. Differences in gene content and regulation also explain why, unlike the Saccharomycotina, fission yeasts cannot use ethanol as a primary carbon source. These analyses elucidate the genome structure and gene regulation of fission yeast and provide tools for investigation across the Schizosaccharomyces clade. PMID:21511999

Rhind, Nicholas; Chen, Zehua; Yassour, Moran; Thompson, Dawn A; Haas, Brian J; Habib, Naomi; Wapinski, Ilan; Roy, Sushmita; Lin, Michael F.; Heiman, David I; Young, Sarah K; Furuya, Kanji; Guo, Yabin; Pidoux, Alison; Chen, Huei Mei; Robbertse, Barbara; Goldberg, Jonathan M.; Aoki, Keita; Bayne, Elizabeth H.; Berlin, Aaron M; Desjardins, Christopher A.; Dobbs, Edward; Dukaj, Livio; Fan, Lin; FitzGerald, Michael G; French, Courtney; Gujja, Sharvari; Hansen, Klavs; Keifenheim, Dan; Levin, Joshua Z.; Mosher, Rebecca A.; Müller, Carolin A.; Pfiffner, Jenna; Priest, Margaret; Russ, Carsten; Smialowska, Agata; Swoboda, Peter; Sykes, Sean M; Vaughn, Matthew; Vengrova, Sonya; Yoder, Ryan; Zeng, Qiandong; Allshire, Robin; Baulcombe, David; Birren, Bruce W.; Brown, William; Ekwall, Karl; Kellis, Manolis; Leatherwood, Janet; Levin, Henry; Margalit, Hanah; Martienssen, Rob; Nieduszynski, Conrad A.; Spatafora, Joseph W.; Friedman, Nir; Dalgaard, Jacob Z.; Baumann, Peter; Niki, Hironori; Regev, Aviv; Nusbaum, Chad

2011-01-01

338

Altered transcription in yeast expressing expanded polyglutamine  

PubMed Central

Expanded polyglutamine tracts are responsible for at least eight fatal neurodegenerative diseases. In mouse models, proteins with expanded polyglutamine cause transcriptional dysregulation before onset of symptoms, suggesting that this dysregulation may be an early event in polyglutamine pathogenesis. Transcriptional dysregulation and cellular toxicity may be due to interaction between expanded polyglutamine and the histone acetyltransferase CREB-binding protein. To determine whether polyglutamine-mediated transcriptional dysregulation occurs in yeast, we expressed polyglutamine tracts in Saccharomyces cerevisiae. Gene expression profiles were determined for strains expressing either a cytoplasmic or nuclear protein with 23 or 75 glutamines, and these profiles were compared to existing profiles of mutant yeast strains. Transcriptional induction of genes encoding chaperones and heat-shock factors was caused by expression of expanded polyglutamine in either the nucleus or cytoplasm. Transcriptional repression was most prominent in yeast expressing nuclear expanded polyglutamine and was similar to profiles of yeast strains deleted for components of the histone acetyltransferase complex Spt/Ada/Gcn5 acetyltransferase (SAGA). The promoter from one affected gene (PHO84) was repressed by expanded polyglutamine in a reporter gene assay, and this effect was mitigated by the histone deacetylase inhibitor, Trichostatin A. Consistent with an effect on SAGA, nuclear expanded polyglutamine enhanced the toxicity of a deletion in the SAGA component SPT3. Thus, an early component of polyglutamine toxicity, transcriptional dysregulation, is conserved in yeast and is pharmacologically antagonized by a histone deacetylase inhibitor. These results suggest a therapeutic approach for treatment of polyglutamine diseases and provide the potential for yeast-based screens for agents that reverse polyglutamine toxicity. PMID:11687606

Hughes, Robert E.; Lo, Russell S.; Davis, Colleen; Strand, Andrew D.; Neal, Cassandra L.; Olson, James M.; Fields, Stanley

2001-01-01

339

[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

340

21 CFR 172.590 - Yeast-malt sprout extract.  

...2014-04-01 2014-04-01 false Yeast-malt sprout extract. 172.590 Section 172.590 Food...Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout extract, as described in this section,...

2014-04-01

341

21 CFR 172.590 - Yeast-malt sprout extract.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Yeast-malt sprout extract. 172.590 Section 172.590 Food...Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout extract, as described in this section,...

2011-04-01

342

21 CFR 172.590 - Yeast-malt sprout extract.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Yeast-malt sprout extract. 172.590 Section 172.590 Food...Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout extract, as described in this section,...

2012-04-01

343

21 CFR 172.590 - Yeast-malt sprout extract.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Yeast-malt sprout extract. 172.590 Section 172.590 Food...Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout extract, as described in this section,...

2013-04-01

344

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

345

Yeast Metabolism Lab Purpose: To determine the effects of different  

E-print Network

O + energy sugar + oxygen carbon dioxide + water + energy Hypothesis: Make a prediction about which treatment (yeast+water, yeast+glucose, or yeast+sweetener) will produce the most carbon dioxide (CO2) from cellular respiration. Materials: Empty water bottles (3), glucose, artificial sweetener, warm water (~40°C

Rose, Michael R.

346

Media for preservative resistant yeasts: a collaborative study  

Microsoft Academic Search

An international collaborative study was carried out to determine the most effective medium for selective isolation and enumeration of preservative resistant yeasts. Such a medium should prevent the growth of other yeasts such as Saccharomyces cerevisiae that are tolerant to lower levels of commonly used food preservatives, and sensitive yeasts such as Rhodotomla species. The study compared two non-selective media

Ailsa D. Hocking

1996-01-01

347

DETECTION, IDENTIFICATION AND ENUMERATION METHODS FOR SPOILAGE YEASTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Microbiological spoilage of foods and beverages is caused by a wide variety of bacteria, molds and yeasts. Yeast growth is favored by low pH, generally 5.5 or lower, and by the presence of sugars, organic acids and other easily metabolized carbon sources. Yeast spoilage is often manifested by grow...

348

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

349

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

350

Interactions Between Yeasts and Grapevines: Filamentous Growth, Endopolygalacturonase and Phytopathogenicity of Colonizing Yeasts  

Microsoft Academic Search

It has been clearly established that phytopathogenic fungi, bacteria, and viruses exert biotic stresses on plants. Much less\\u000a is known, however, about the interactions between enological species of yeast and their host plants. In a previous study,\\u000a we described how Saccharomyces cerevisiae, the most common enological yeast, can act as a grapevine (Vitis vinifera L.) pathogen, causing growth retardation or

Sabine Gognies; Essaïd Ait Barka; Angélique Gainvors-Claisse; Abdel Belarbi

2006-01-01

351

Reaction characteristics of an immobilized yeast producing ethanol.  

PubMed

The reaction behavior of Saccharomyces formaosensis imobilized by polyacrylamide gel is presented. Two types of the immobilized yeast are studied, i. e. the immobilized resting yeast and the immobilized growing yeast. For both of the yeast, reaction retes are expressed by the Michaelis-Menten type equation with a linear ethanol inhibition factor. The Michaelis constants aere close each other, but considerably larger that of native S. cerevisiae. Distribution of the growing yeast cell inside the carrier gel is presented. It is found that the cell density is somewhat higher near the surface of the carrier. PMID:18548627

Furusaki, S; Seki, M; Fukumura, K

1983-12-01

352

Carbon source dependent promoters in yeasts  

PubMed Central

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

2014-01-01

353

Morphology of the Yeast Endocytic Pathway  

PubMed Central

Positively charged Nanogold (Nanoprobes, Stony Brook, NY) has been developed as a new marker to follow the endocytic pathway in yeast. Positively charged Nanogold binds extensively to the surface of yeast spheroplasts and is internalized in an energy-dependent manner. Internalization of gold is blocked in the end3 mutant. During a time course of incubation of yeast spheroplasts with positively charged Nanogold at 15°C, the gold was detected sequentially in small vesicles, a peripheral, vesicular/tubular compartment that we designate as an early endosome, a multivesicular body corresponding to the late endosome near the vacuole, and in the vacuole. Experiments examining endocytosis in the sec18 mutant showed an accumulation of positively charged Nanogold in approximately 30–50 nm diameter vesicles. These vesicles most likely represent the primary endocytic vesicles as no other intermediates were detected in the mutant cells, and they correspond in size to the first vesicles detected in wild-type spheroplasts at 15°C. These data lend strong support to the idea that the internalization step of endocytosis in yeast involves formation of small vesicles of uniform size from the plasma membrane. PMID:9436999

Prescianotto-Baschong, Cristina; Riezman, Howard

1998-01-01

354

Histone acetylation and deacetylation in yeast  

Microsoft Academic Search

Histone acetylation and deacetylation in the yeast Saccharomyces cerevisiae occur by targeting acetyltransferase and deacetylase enzymes to gene promoters and, in an untargeted and global manner, by affecting most nucleosomes. Recently, new roles for histone acetylation have been uncovered, not only in transcription but also in DNA replication, repair and heterochromatin formation. Interestingly, specific acetylatable lysines can function as binding

Siavash K. Kurdistani; Michael Grunstein

2003-01-01

355

The glucose signaling network in yeast  

PubMed Central

Background Most cells possess a sophisticated mechanism for sensing glucose and responsing to it appropriately. Glucose sensing and signaling in the budding yeast Saccharomyces cerevisiae represents an important paradigm for understanding how extracellular signals lead to changes in the gene expression program in eukaryotes. Scope of review This review focuses on the yeast glucose sensing and signaling pathways that operate in a highly regulated and cooperative manner to bring about glucose-induction of HXT gene expression. Major conclusions The yeast cells possess a family of glucose transporters (HXTs), with different kinetic properties. They employ three major glucose signaling pathways— Rgt2/Snf3, AMPK, and cAMP-PKA—to express only those transporters best suited for the amounts of glucose available. We discuss the current understanding of how these pathways are integrated into a regulatory network to ensure efficient uptake and utilization of glucose. General significance Elucidating the role of multiple glucose signals and pathways involved in glucose uptake and metabolism in yeast may reveal the molecular basis of glucose homeostasis in humans, especially under pathological conditions, such as hyperglycemia in diabetics and the elevated rate of glycolysis observed in many solid tumors. PMID:23911748

Kim, Jeong-Ho; Roy, Adhiraj; Jouandot, David; Cho, Kyu Hong

2013-01-01

356

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

357

Actin and Endocytosis in Budding Yeast  

PubMed Central

Endocytosis, the process whereby the plasma membrane invaginates to form vesicles, is essential for bringing many substances into the cell and for membrane turnover. The mechanism driving clathrin-mediated endocytosis (CME) involves > 50 different protein components assembling at a single location on the plasma membrane in a temporally ordered and hierarchal pathway. These proteins perform precisely choreographed steps that promote receptor recognition and clustering, membrane remodeling, and force-generating actin-filament assembly and turnover to drive membrane invagination and vesicle scission. Many critical aspects of the CME mechanism are conserved from yeast to mammals and were first elucidated in yeast, demonstrating that it is a powerful system for studying endocytosis. In this review, we describe our current mechanistic understanding of each step in the process of yeast CME, and the essential roles played by actin polymerization at these sites, while providing a historical perspective of how the landscape has changed since the preceding version of the YeastBook was published 17 years ago (1997). Finally, we discuss the key unresolved issues and where future studies might be headed. PMID:25657349

Goode, Bruce L.; Eskin, Julian A.; Wendland, Beverly

2015-01-01

358

Deoxyribonucleic Acid Base Composition in Yeasts  

PubMed Central

The deoxyribonucleic acid base composition of 15 species of yeasts was determined to obtain further clues to or supporting evidence for their taxonomic position. Species examined belonged to the genera Saccharomyces, Debaryomyces, Lodderomyces, Metschnikowia, and Candida. The range of moles per cent guanine plus cytosine (GC content) for all yeasts examined extended from 34.9 to 48.3%. The sporogenous species and the asporogenous yeasts spanned the range with 36.6 to 48.3% GC and 34.9 to 48% GC, respectively. Three Saccharomyces species (S. rosei and related species) exhibited significantly higher GC contents than S. cerevisiae, whereas the fermentative species D. globosus revealed a%GC more aligned to the S. rosei group than to the nonfermentative D. hansenii. Similar GC contents were demonstrated by L. elongasporus and its proposed imperfect form C. parapsilosis. The range of GC contents of various strains of three Metschnikowia species studied was 6.1%, with the type strain of M. pulcherrima having the highest GC content (48.3%) of all of the yeasts examined. PMID:5764346

Meyer, Sally A.; Phaff, H. J.

1969-01-01

359

Coenzyme Q systems in ascomycetous black yeasts  

Microsoft Academic Search

72 Strains belonging to 44 species of ascomycetous black yeasts were analyzed for their coenzyme Q systems. Prevalent were Q-10 and dihydrogenated Q-10 systems. Members of the Dothidealean suborder Dothideineae have Q-10 (H2), while those belonging to the suborder Pseudosphaeriineae mostly have Q-10. The anamorph genus Exophiala Carmichael and the teleomorph genus Capronia Sacc. seem to be heterogenous.

Y. Yamada; Kazue Sugihara; G. W. Eijk; H. J. Roeijmans; G. S. Hoog

1989-01-01

360

Replication Dynamics of the Yeast Genome  

Microsoft Academic Search

Oligonucleotide microarrays were used to map the detailed topography of chromosome replication in the budding yeast Saccharomyces cerevisiae. The times of replication of thousands of sites across the genome were determined by hybridizing replicated and unreplicated DNAs, isolated at different times in S phase, to the microarrays. Origin activations take place continuously throughout S phase but with most firings near

M. K. Raghuraman; Elizabeth A. Winzeler; David Collingwood; Sonia Hunt; Lisa Wodicka; Andrew Conway; David J. Lockhart; Ronald W. Davis; Bonita J. Brewer; Walton L. Fangman

2001-01-01

361

A yeast model of Down syndrome  

Microsoft Academic Search

The recent discovery that cellular proliferation was reduced in aneuploid haploid yeast supports a long-standing argument that the developmental neurophenotype of Down syndrome is not uniquely a result of the effects of increased gene dosage. Instead, some phenotypic outcomes appear to resemble those caused by disrupted cellular homeostasis induced by aneuploidy. Decreased cellular proliferation has been identified in the cerebellum

Randal X. Moldrich

2007-01-01

362

Commitment to meiosis in fission yeast  

Microsoft Academic Search

Mutants of Schizosaccharomyces pombe blocked during meiosis were analysed with respect to the induction of diploid mitotic division. Wild type zygotes of this yeast can form diploid colonies with a low probability (ca. 1%) when they are transferred to fresh growth medium. Mutants of three genes affecting meiosis responded to the shift by forming diploid colonies with high yield (ca.

Richard Egel

1973-01-01

363

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.

364

Microfermentation Test For Identification Of Yeast  

NASA Technical Reports Server (NTRS)

Microfermentation test developed as supplementary method for use in identifying yeasts, especially in clinical and environmental studies. In comparison with traditional fermentation tests, simpler and easier, and requiries less equipment, material, and laboratory space. Results obtained in days instead of weeks.

Pierson, D. L.; Mishra, S. K.; Molina, Thomas C.

1995-01-01

365

Inventions on baker's yeast strains and specialty ingredients.  

PubMed

Baker's yeast is one of the oldest food microbial starters. Between 1927 and 2008, 165 inventions on more than 337 baker's yeast strains were patented. The first generation of patented yeast strains claimed improved biomass yield at the yeast plant, higher gassing power in dough or better survival to drying to prepare active dry baker's yeast. Especially between 1980 and 1995, a major interest was given to strains for multiple bakery applications such as dough with variable sugar content and stored at refrigeration (cold) or freezing temperatures. During the same period, genetically engineered yeast strains became very popular but did not find applications in the baking industry. Since year 2000, patented baker's yeast strains claimed aroma, anti-moulding or nutritive properties to better meet the needs of the baking industry. In addition to patents on yeast strains, 47 patents were issued on baker's yeast specialty ingredients for niche markets. This review shows that patents on baker's yeast with improved characteristics such as aromatic or nutritive properties have regularly been issued since the 1920's. Overall, it also confirms recent interest for a very wide range of tailored-made yeast-based ingredients for bakery applications. PMID:20653532

Gélinas, Pierre

2009-06-01

366

Evaluation of seasonal chemical composition, antibacterial, antioxidant and anticholinesterase activity of essential oil from Eugenia brasiliensis Lam.  

PubMed

This study describes the seasonal composition and the antibacterial, antioxidant and anticholinesterase activity of the essential oil from Eugenia brasiliensis leaves. Analysis by using GC allowed the identification of 40 compounds. It was observed that the monoterpenes varied more (42%) than the sesquiterpenes (14%), and that the monoterpene hydrocarbons suffered the greatest variation throughout the year (64%). Major compounds were spathulenol in the spring (16.02 ± 0.44%) and summer (18.17 ± 0.41%), ?-cadinol in the autumn (12.83 ± 0.03%) and ?-pinene (15.94 ± 0.58%) in the winter. Essential oils were tested for their antibacterial activity, and the best result was obtained from the autumn oil, with MIC = 500 ?g mL(- 1) against Staphylococcus saprophyticus and Pseudomonas aeruginosa. Antioxidant activity was evaluated using DPPH, lipid peroxidation and iron-reducing power assays, as well as the anticholinesterase activity. Both tests showed a weak performance of the essential oils. PMID:25219800

Siebert, Diogo Alexandre; Tenfen, Adrielli; Yamanaka, Celina Noriko; de Cordova, Caio Maurício Mendes; Scharf, Dilamara Riva; Simionatto, Edésio Luiz; Alberton, Michele Debiasi

2015-02-01

367

Tapironema coronatum n. gen., n. sp. (Trichostrongyloidea-Cooperiidae-Obeliscoidinae), a parasite of Holochilus brasiliensis and Tapirus terrestris.  

PubMed

In this paper we provide a description of Tapironema coronatum n. gen. n. sp. (Trichostrongyloidea, Obeliscoidinae) from the cricetid Holochilus brasiliensis or "water rat" in Argentina (Type material) and from Tapirus terrestris in French Guyana (voucher material in poor condition). The new genus is characterized by a corona radiata, an oesophageal tooth, a bilaterally synlophe with about 73 (male), 122 (female) cuticular ridges, a caudal bursa pattern 2-1-2 with rays 5 and 6 parallel and close together and rays 5 longer than rays 3. The most closely related genus is the monospecific Teporingonema Harris, 1985, from a Mexican lagomorph, Romerolagus. The cephalic extremity of this parasite is redescribed after the type-material. The systematic position of Teporingonema amongst the Obeliscoidinae is defined and the hypotheses concerning the origin of this sub family are provided. PMID:9587607

Durette-Desset, M C; Chabaud, A G; Sutton, C A

1997-09-01

368

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.; Simões, C. M. O.

2013-01-01

369

CARACTERIZAÇÃO COLORIMÉTRICA DAS MADEIRAS DE MUIRAPIRANGA (Brosimum rubescensTaub.) E DE SERINGUEIRA (Hevea brasiliensis, clone Tjir 16 Müll Arg.) VISANDO À UTILIZAÇÃO EM INTERIORES COLORIMETRY CHARACTERIZATION OF THE WOOD OF MUIRAPIRANGA (Brosimum rubescens Taub.) AND OF RUBBER TREE (Hevea brasiliensis, clone Tjir 16 Müll Arg.) AIMING AT INSIDE USE  

Microsoft Academic Search

Although recent, the technique for the determination of wood color through the quantitative colorimetry seems to be efficient. The CIELAB 1976 system cuhich determines the L *, a *, b *, C and h * colorimetric parameters, seemed to be efficient for the determination of the color of the muirapiranga wood (Brosimum rubescens) and of rubbertree (Hevea brasiliensis, clone Tjir

Cristine da Silva Autran; Joaquim Carlos Gonçalez

2006-01-01

370

Misidentification of clinical yeast isolates by using the updated Vitek Yeast Biochemical Card.  

PubMed Central

The Vitek Yeast Biochemical Card (YBC) is widely used as a rapid identification (RI) (within 48 h) system for clinical yeast isolates. We compared the RI results obtained by the YBC technique with matched results obtained with the API 20C system. The RI of germ tube-negative yeasts isolated from 222 clinical specimens was performed with the YBC system, and the results were compared with those of standard identifications obtained by using the API 20C system and morphology, with additional biochemical reactions performed as required. Commonly isolated yeasts (Candida albicans [n = 29], Candida tropicalis [n = 40], Torulopsis [Candida] glabrata [n = 28], Candida parapsilosis [n = 12], and Cryptococcus neoformans [n = 14]) were generally well identified (115 of 123 [93%] identified correctly, with only C. albicans, C. tropicalis, and C. neoformans mis- or unidentified more than once). The RI of less commonly isolated yeasts included in the YBC database, however, was less successful (54 of 99 [55%] correct). The YBC card failed to identify 42% (10 of 24) of Candida krusei isolates, 80% (4 of 5) of Candida lambica isolates, 88% (7 of 8) of Trichosporon beigelii isolates, and 83% (10 of 12) of Cryptococcus isolates (non-C. neoformans species). For most identification failures (79%; 42 of 53) there was no identification by the end of 48 h; the other identification failures (21%; 11 of 53) gave definite but incorrect identifications. Of eight rare clinical yeast isolates not included in the Vitek database, six were correctly, not identified, while two (25%) were falsely assigned a definite RI (one Hansenula fabianii isolate was identified as Rhodotorula glutinis, and one Hansenula isolate [non-Hansenula anomala] was identified as Hansenula anomala). While the Vitek YBC rapidly and adequately identifies common yeast isolates, it fails in the RI of more unusual organisms. PMID:7883873

Dooley, D P; Beckius, M L; Jeffrey, B S

1994-01-01

371

Misidentification of clinical yeast isolates by using the updated Vitek Yeast Biochemical Card.  

PubMed

The Vitek Yeast Biochemical Card (YBC) is widely used as a rapid identification (RI) (within 48 h) system for clinical yeast isolates. We compared the RI results obtained by the YBC technique with matched results obtained with the API 20C system. The RI of germ tube-negative yeasts isolated from 222 clinical specimens was performed with the YBC system, and the results were compared with those of standard identifications obtained by using the API 20C system and morphology, with additional biochemical reactions performed as required. Commonly isolated yeasts (Candida albicans [n = 29], Candida tropicalis [n = 40], Torulopsis [Candida] glabrata [n = 28], Candida parapsilosis [n = 12], and Cryptococcus neoformans [n = 14]) were generally well identified (115 of 123 [93%] identified correctly, with only C. albicans, C. tropicalis, and C. neoformans mis- or unidentified more than once). The RI of less commonly isolated yeasts included in the YBC database, however, was less successful (54 of 99 [55%] correct). The YBC card failed to identify 42% (10 of 24) of Candida krusei isolates, 80% (4 of 5) of Candida lambica isolates, 88% (7 of 8) of Trichosporon beigelii isolates, and 83% (10 of 12) of Cryptococcus isolates (non-C. neoformans species). For most identification failures (79%; 42 of 53) there was no identification by the end of 48 h; the other identification failures (21%; 11 of 53) gave definite but incorrect identifications. Of eight rare clinical yeast isolates not included in the Vitek database, six were correctly, not identified, while two (25%) were falsely assigned a definite RI (one Hansenula fabianii isolate was identified as Rhodotorula glutinis, and one Hansenula isolate [non-Hansenula anomala] was identified as Hansenula anomala). While the Vitek YBC rapidly and adequately identifies common yeast isolates, it fails in the RI of more unusual organisms. PMID:7883873

Dooley, D P; Beckius, M L; Jeffrey, B S

1994-12-01

372

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

373

The role of adjuvants in therapeutic protection against paracoccidioidomycosis after immunization with the P10 peptide  

PubMed Central

Paracoccidioidomycosis (PCM), a common chronic mycosis in Latin America, is a granulomatous systemic disease caused by the thermo-dimorphic fungus Paracoccidioides brasiliensis. The glycoprotein gp43 is the main antigen target of P. brasiliensis and a 15-mer internal peptide (QTLIAIHTLAIRYAN), known as P10, defines a major CD4+-specific T cell epitope. Previous results have indicated that, besides having a preventive role in conventional immunizations prior to challenge with the fungus, protective anti-fungal effects can be induced in P. brasiliensis-infected mice treated with P10 administered with complete Freund’s adjuvant (CFA). The peptide elicits an IFN-?-dependent Th1 immune response and is the main candidate for effective immunotherapy of patients with PCM, as an adjunctive approach to conventional chemotherapy. In the present study we tested the therapeutic effects of P10 combined with different adjuvants [aluminum hydroxide, CFA, flagellin, and the cationic lipid dioctadecyl-dimethylammonium bromide (DODAB)] in BALB/c mice previously infected with the P. brasiliensis Pb18 strain. Significant reductions in the number of colony forming units of the fungus were detected in lungs of mice immunized with P10 associated with the different adjuvants 52 days after infection. Mice treated with DODAB and P10, followed by mice treated with P10 and flagellin, showed the most prominent effects as demonstrated by the lowest numbers of viable yeast cells as well as reductions in granuloma formation and fibrosis. Concomitantly, secretion of IFN-? and TNF-?, in contrast to interleukin (IL)-4 and IL-10, was enhanced in the lungs of mice immunized with P10 in combination with the tested adjuvants, with the best results observed in mice treated with P10 and DODAB. In conclusion, the present results demonstrate that the co-administration of the synthetic P10 peptide with several adjuvants, particularly DODAB, have significant therapeutic effects in experimental PCM. PMID:22586420

Mayorga, Oriana; Muñoz, Julian E.; Lincopan, Nilton; Teixeira, Aline F.; Ferreira, Luis C. S.; Travassos, Luiz R.; Taborda, Carlos P.

2012-01-01

374

Chemical composition and larvicidal properties of the essential oils from Drimys brasiliensis Miers (Winteraceae) on the cattle tick Rhipicephalus ( Boophilus ) microplus and the brown dog tick Rhipicephalus sanguineus  

Microsoft Academic Search

The essential oil obtained from leaves and stem barks of the Southern Brazilian native Drimys brasiliensis Miers, a tree with medicinal properties, was analyzed by gas chromatography (GC) and GC\\/mass spectrometry (MS). The oil was\\u000a characterized by sesquiterpenoids (66%), cyclocolorenone being the most abundant (30.4%), followed by bicyclogermacrene (11.8%)\\u000a and alpha-gurjunene (6.0%). Laboratory tests were carried out to determine the

Vera Lúcia Sardá Ribeiro; Verônica Rolim; Sérgio Bordignon; Amélia T. Henriques; Gilséia G. Dorneles; Renata P. Limberger; Gilsane von Poser

2008-01-01

375

Molecular cloning, expression and characterization of cDNA encoding cis-prenyltransferases from Hevea brasiliensis: A key factor participating in natural rubber biosynthesis  

Microsoft Academic Search

Natural rubber from Hevea brasiliensis is a high molecular mass polymer of isoprene units with cis-configuration. The enzyme responsible for the cis-1,4-polymerization of iso- prene units has been identified as a particle-bound rubber transferase, but no gene encoding this enzyme has been cloned from rubber-producing plants. By using sequence information from the conserved regions of cis-prenyl chain elongating enzymes that

Kasem Asawatreratanakul; Yuan-Wei Zhang; Dhirayos Wititsuwannakul; Rapepun Wititsuwannakul; Seiji Takahashi; Atiya Rattanapittayaporn; Tanetoshi Koyama

2003-01-01

376

Three genes encode 3-hydroxy-3-methylglutaryl-coenzyme A reductase in Hevea brasiliensis: hmg1 and hmg3 are differentially expressed  

Microsoft Academic Search

The enzyme 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR) catalyses an important step in isoprenoid biosynthesis in plants. In Hevea brasiliensis, HMGR is encoded by a small gene family comprised of three members, hmg1, hmg2 and hmg3. We have previously described hmg1 and hmg2 (Plant Mol Biol 16: 567–577, 1991). Here we report the isolation and characterization of hmg3 genomic and cDNA clones.

Mee-Len Chye; Chio-Tee Tan; Nam-Hai Chua

1992-01-01

377

The ubiquitin code of yeast permease trafficking.  

PubMed

Yeast permeases, that act as transporters for nutrients including amino acids, nucleobases and metals, provide a powerful model system for dissecting the physiological control of membrane protein trafficking. Modification of these transporters by ubiquitin is known to target them for degradation in the vacuole, the degradation organelle of fungi. Recent studies have uncovered the role of specific adaptors for recruiting the Rsp5 ubiquitin ligase to these proteins. In addition, the role of ubiquitin at different trafficking steps including early endocytosis, sorting into the multivesicular body (MVB) pathway and Golgi-to-endosome transit is now becoming clear. In particular, K63-linked ubiquitin chains now emerge as a specific signal for protein sorting into the MVB pathway. A complete view of the ubiquitin code governing yeast permease trafficking might not be far off. PMID:20138522

Lauwers, Elsa; Erpapazoglou, Zoi; Haguenauer-Tsapis, Rosine; André, Bruno

2010-04-01

378

Kinetic mechanism of yeast inorganic pyrophosphatase  

Microsoft Academic Search

The kinetic mechanism of yeast inorganic pyrophosphatase (PPase) was examined by carrying out initial velocity studies. Ca2+ and Rh(HâO)4(methylenediphosphonate) (Rh(HâO)4PCP) were used as dead-end inhibitors to study the order of binding of Cr(HâO)4PP to the substrate site and Mg2+ to the low affinity activator site on the enzyme. Competitive inhibition was observed for Ca2+ vs Mg2+ (Kis = 0.93 +\\/-

R. J. Barry; D. Dunaway-Mariano

1987-01-01

379

The core meiotic transcriptome in budding yeasts  

Microsoft Academic Search

We used high-density oligonucleotide microarrays to analyse the genomes and meiotic expression patterns of two yeast strains, SK1 and W303, that display distinct kinetics and efficiencies of sporulation. Hybridization of genomic DNA to arrays revealed numerous gene deletions and polymorphisms in both backgrounds. The expression analysis yielded approximately 1,600 meiotically regulated genes in each strain, with a core set of

Michael Primig; Roy M. Williams; Elizabeth A. Winzeler; Gela G. Tevzadze; Andrew R. Conway; Seung Y. Hwang; Ronald W. Davis; Rochelle Easton Esposito

2000-01-01

380

Isolation of Yeast DNA Prepare in advance  

E-print Network

supernatant. 2. Resuspend cell pellet in 0.5 ml TE buffer. Transfer to 1.5 ml microfuge tube. Spin at top. Transfer supernatant to fresh tube. Do not transfer pellet material (insoluble cell debris and cell wall. · Powdered dry ice (2-4 lbs). 1. Collect 5-10 OD units of yeast cells (e.g., 5 ml saturated SD culture at OD

Aris, John P.

381

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

382

Transfer RNA methylating activity of yeast mitochondria  

PubMed Central

Mitochondria isolated from Saccharomyces cerevisiae and purified in Urografin or sucrose gradient contain tRNA methylating activity with specificities different from those of the cytoplasm. The main reaction product, using E.coli tRNA as methyl group acceptor, is N2,-N2-dimethylguanine. The corresponding mitochondrial methylase is coded by nuclear DNA. A DNA methylating activity is also associated with yeast mitochondria. PMID:10793751

Smolar, Nina; Svensson, Ingvar

1974-01-01

383

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

384

Mitochondrial NAD Dependent Aldehyde Dehydrogenase either from Yeast or Human Replaces Yeast Cytoplasmic NADP Dependent Aldehyde Dehydrogenase for the Aerobic Growth of Yeast on Ethanol  

PubMed Central

Background In a previous study, we deleted three aldehyde dehydrogenase (ALDH) genes, involved in ethanol metabolism, from yeast S. cerevisiae and found that the triple deleted yeast strain did not grow on ethanol as sole carbon source. The ALDHs were NADP dependent cytosolic ALDH1, NAD dependent mitochondrial ALDH2 and NAD/NADP dependent mitochondrial ALDH5. Double deleted strain ?ALDH2+?ALDH5 or ?ALDH1+?ALDH5 could grow on ethanol. However, the double deleted strain ?ALDH1+?ALDH2 did not grow in ethanol. Methods Triple deleted yeast strain was used. Mitochondrial NAD dependent ALDH from yeast or human was placed in yeast cytosol. Results In the present study we found that a mutant form of cytoplasmic ALDH1 with very low activity barely supported the growth of the triple deleted strain (?ALDH1+?ALDH2+?ALDH5) on ethanol. Finding the importance of NADP dependent ALDH1 on the growth of the strain on ethanol we examined if NAD dependent mitochondrial ALDH2 either from yeast or human would be able to support the growth of the triple deleted strain on ethanol if the mitochondrial form was placed in cytosol. We found that the NAD dependent mitochondrial ALDH2 from yeast or human was active in cytosol and supported the growth of the triple deleted strain on ethanol. Conclusion This study showed that coenzyme preference of ALDH is not critical in cytosol of yeast for the growth on ethanol. PMID:23454351

Mukhopadhyay, Abhijit; Wei, Baoxian; Weiner, Henry

2013-01-01

385

Production of recombinant proteins by yeast cells.  

PubMed

Yeasts are widely used in production of recombinant proteins of medical or industrial interest. For each individual product, the most suitable expression system has to be identified and optimized, both on the genetic and fermentative level, by taking into account the properties of the product, the organism and the expression cassette. There is a wide range of important yeast expression hosts including the species Saccharomyces cerevisiae, Pichia pastoris, Hansenula polymorpha, Kluyveromyces lactis, Schizosaccharomyces pombe, Yarrowia lipolytica and Arxula adeninivorans, with various characteristics such as being thermo-tolerant or halo-tolerant, rapidly reaching high cell densities or utilizing unusual carbon sources. Several strains were also engineered to have further advantages, such as humanized glycosylation pathways or lack of proteases. Additionally, with a large variety of vectors, promoters and selection markers to choose from, combined with the accumulated knowledge on industrial-scale fermentation techniques and the current advances in the post-genomic technology, it is possible to design more cost-effective expression systems in order to meet the increasing demand for recombinant proteins and glycoproteins. In this review, the present status of the main and most promising yeast expression systems is discussed. PMID:21964262

Celik, Eda; Cal?k, P?nar

2012-01-01

386

On the modeling of endocytosis in yeast  

E-print Network

The cell membrane deforms during endocytosis to surround extracellular material and draw it into the cell. Experiments on endocytosis in yeast all agree that (i) actin polymerizes into a network of filaments exerting active forces on the membrane to deform it and (ii) the large scale membrane deformation is tubular in shape. There are three competing proposals, in contrast, for precisely how the actin filament network organizes itself to drive the deformation. We use variational approaches and numerical simulations to address this competition by analyzing a meso-scale model of actin-mediated endocytosis in yeast. The meso-scale model breaks up the invagination process into three stages: (i) initiation, where clathrin interacts with the membrane via adaptor proteins, (ii) elongation, where the membrane is then further deformed by polymerizing actin filaments, followed by (iii) pinch-off. Our results suggest that the pinch-off mechanism may be assisted by a pearling-like instability. We rule out two of the three competing proposals for the organization of the actin filament network during the elongation stage. These two proposals could possibly be important in the pinch-off stage, however, where additional actin polymerization helps break off the vesicle. Implications and comparisons with earlier modeling of endocytosis in yeast are discussed.

T. Zhang; R. Sknepnek; M. J. Bowick; J. M. Schwarz

2013-10-31

387

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

388

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

389

The Yeast Deletion Collection: A Decade of Functional Genomics  

PubMed Central

The yeast deletion collections comprise >21,000 mutant strains that carry precise start-to-stop deletions of ?6000 open reading frames. This collection includes heterozygous and homozygous diploids, and haploids of both MATa and MAT? mating types. The yeast deletion collection, or yeast knockout (YKO) set, represents the first and only complete, systematically constructed deletion collection available for any organism. Conceived during the Saccharomyces cerevisiae sequencing project, work on the project began in 1998 and was completed in 2002. The YKO strains have been used in numerous laboratories in >1000 genome-wide screens. This landmark genome project has inspired development of numerous genome-wide technologies in organisms from yeast to man. Notable spinoff technologies include synthetic genetic array and HIPHOP chemogenomics. In this retrospective, we briefly describe the yeast deletion project and some of its most noteworthy biological contributions and the impact that these collections have had on the yeast research community and on genomics in general. PMID:24939991

Giaever, Guri; Nislow, Corey

2014-01-01

390

Isolation and characterization of ethanol tolerant yeast strains  

PubMed Central

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

391

Yeast Genomics for Bread, Beer, Biology, Bucks and Breath  

NASA Astrophysics Data System (ADS)

The rapid advances and scale up of projects in DNA sequencing dur ing the past two decades have produced complete genome sequences of several eukaryotic species. The versatile genetic malleability of the yeast, and the high degree of conservation between its cellular processes and those of human cells have made it a model of choice for pioneering research in molecular and cell biology. The complete sequence of yeast genome has proven to be extremely useful as a reference towards the sequences of human and for providing systems to explore key gene functions. Yeast has been a ‘legendary model’ for new technologies and gaining new biological insights into basic biological sciences and biotechnology. This chapter describes the awesome power of yeast genetics, genomics and proteomics in understanding of biological function. The applications of yeast as a screening tool to the field of drug discovery and development are highlighted and the traditional importance of yeast for bakers and brewers is discussed.

Sakharkar, Kishore R.; Sakharkar, Meena K.

392

Taming wild yeast: potential of conventional and nonconventional yeasts in industrial fermentations.  

PubMed

Yeasts are the main driving force behind several industrial food fermentation processes, including the production of beer, wine, sake, bread, and chocolate. Historically, these processes developed from uncontrolled, spontaneous fermentation reactions that rely on a complex mixture of microbes present in the environment. Because such spontaneous processes are generally inconsistent and inefficient and often lead to the formation of off-flavors, most of today's industrial production utilizes defined starter cultures, often consisting of a specific domesticated strain of Saccharomyces cerevisiae, S. bayanus, or S. pastorianus. Although this practice greatly improved process consistency, efficiency, and overall quality, it also limited the sensorial complexity of the end product. In this review, we discuss how Saccharomyces yeasts were domesticated to become the main workhorse of food fermentations, and we investigate the potential and selection of nonconventional yeasts that are often found in spontaneous fermentations, such as Brettanomyces, Hanseniaspora, and Pichia spp. PMID:24773331

Steensels, Jan; Verstrepen, Kevin J

2014-01-01

393

Genome-wide identification and characterization of WRKY gene family in Hevea brasiliensis.  

PubMed

WRKY proteins constitute a large family of transcription factors. In this study, we identified 81 WRKY genes (named HbWRKY1 to HbWRKY81) in the latest rubber tree genome. Tissue-specific expression profiles showed that 74 HbWRKYs were expressed in at least one of the tissues and the other 7 genes showed very low expression in all tissues tested, which suggested that HbWRKYs took part in many cellular processes. The responses of 20 selected HbWRKYs to jasmonic acid (JA) and ethylene (ET) were analyzed in the latex. 17 HbWRKYs responded to at least one treatment, which included 15 HbWRKYs responding to JA treatment, 15 HbWRKYs to ET, which suggested that these HbWRKYs were regulated by JA and ET. We also observed that HbWRKY3, 14, and 55 bind HbSRPP promoter and activate the transcription in yeast. This study suggests that HbWRKY proteins maybe involved in the transcriptional regulation of nature rubber biosynthesis. PMID:24793160

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

2014-07-01

394

Ogataea allantospora sp. nov., an ascomycetous yeast species from phylloplane  

Microsoft Academic Search

Following a two-step enrichment in methanol containing broth, methylotrophic yeast strains were isolated from about 45% of\\u000a the leaf samples collected from broad leafed deciduous trees and from herbs in Hungary. During the enrichment process protists\\u000a predating the yeasts were observed. Based on standard phenotypical tests and the D1\\/D2 domain sequences of the large subunit\\u000a (26S) rDNA of the yeast

Gábor Péter; Judit Tornai-Lehoczki; Dénes Dlauchy

2007-01-01

395

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

396

Gene copy number and polyploidy on products formation in yeast  

Microsoft Academic Search

Yeast, such as Saccharomyces cerevisiae or Kluyveromyces lactis is appropriate strain for ethanol production or some useful compounds production. Cellulases expressing yeast can ferment\\u000a ethanol from cellulosic materials; however, the productivity should be increase more and more. To improve and engineer the\\u000a productivity, the target gene(s) were introduced into yeast genome. Generally, using genetic engineering, increasing integrated\\u000a gene numbers are

Ryosuke Yamada; Tsutomu Tanaka; Chiaki Ogino; Akihiko Kondo

2010-01-01

397

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

398

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

399

Cytokinesis depends on the motor domains of myosin-II in fission yeast but not in budding yeast.  

PubMed

Budding yeast possesses one myosin-II, Myo1p, whereas fission yeast has two, Myo2p and Myp2p, all of which contribute to cytokinesis. We find that chimeras consisting of Myo2p or Myp2p motor domains fused to the tail of Myo1p are fully functional in supporting budding yeast cytokinesis. Remarkably, the tail alone of budding yeast Myo1p localizes to the contractile ring, supporting both its constriction and cytokinesis. In contrast, fission yeast Myo2p and Myp2p require both the catalytic head domain as well as tail domains for function, with the tails providing distinct functions (Bezanilla and Pollard, 2000). Myo1p is the first example of a myosin whose cellular function does not require a catalytic motor domain revealing a novel mechanism of action for budding yeast myosin-II independent of actin binding and ATPase activity. PMID:16148042

Lord, Matthew; Laves, Ellen; Pollard, Thomas D

2005-11-01

400

Effects of Pretreating Serum Samples on the Performance of a Latex Agglutination Test for Serodiagnosis of Paracoccidioidomycosis  

PubMed Central

Paracoccidioidomycosis (PCM) is a fungal disease caused by Paracoccidioides brasiliensis, and Brazil is one of the principal countries where it is endemic. Diagnosis is based on the observation of budding P. brasiliensis yeast in clinical specimens from patients; however, the sensitivity of the visualization of fungi is low, indicating that serological tests are used for early diagnosis. The double-immunodiffusion test (ID) is the “gold standard” test for serology in PCM, although the execution of this test requires the availability of laboratorial infrastructure. We report the improved performance of a latex agglutination test (LAT) by pretreating 30 serum samples from PCM patients and 71 controls (histoplasmosis and aspergillosis patients, patients with bacterial infections, and normal human sera) with a dilution buffer incubated at 37°C for 30 min. The sensitivity and specificity of the LAT test in the nonpretreated samples were 73% and 79%, respectively. However, when samples were pretreated, the sensitivity and specificity of the test increased to 90%. In this study, we did not observe cross-reactivity with histoplasmosis patient sera, but some reactions to sera from patients with aspergillosis and bacterial infections were noted. Normal human sera were not reactive in our tests. These results indicate the need for the elimination of heterologous reactions so that we can adequately use this method for screening cases of PCM. PMID:22205661

Silveira-Gomes, Fabíola

2012-01-01

401

Typing of Histoplasma capsulatum strains by fatty acid profile analysis  

PubMed Central

The performance of fatty acid profiling for strain differentiation of Histoplasma capsulatum was assessed. Total fatty acids were isolated from the yeast-phase cells of seven stock and two previously unreported clinical strains of H. capsulatum var. capsulatum, as well as from one unreported clinical strain and one stock strain of H. capsulatum var. duboisii, and one strain of each of three other dimorphic zoopathogenic fungal species, Blastomyces dermatitidis, Paracoccidioides brasiliensis and Sporothrix schenckii. Different colony morphology and pigmentation types of the H. capsulatum strains were also included. The most frequently occurring fatty acids were oleic, palmitic, stearic and linoleic acids. There were variations in the relative percentage fatty acid contents of H. capsulatum strains that could be used for strain identification and discrimination. Differentiation between H. capsulatum strains was achieved by the comparison of detected fatty acids accompanied by principal component analysis using calculated Varimax-rotated principal component loadings. Statistical analysis yielded three major principal components that explained over 94% of total variance in the data. All the strains of H. capsulatum var. capsulatum RFLP classes II and III were grouped into two distinct clusters: the heterogenic RFLP class I formed a large, but also well-defined group, whereas the outgroup strains of H. capsulatum var. duboisii, B. dermatitidis, P. brasiliensis and S. schenckii were shifted away. These data suggest that fatty acid profiling can be used in H. capsulatum strain classification and epidemiological studies that require strain differentiation at the intraspecies level. PMID:17510264

Zarnowski, Robert; Miyazaki, Makoto; Dobrzyn, Agnieszka; Ntambi, James M.; Woods, Jon P.

2009-01-01

402

The antimicrobial activity of lapachol and its thiosemicarbazone and semicarbazone derivatives  

PubMed Central

Lapachol was chemically modified to obtain its thiosemicarbazone and semicarbazone derivatives. These compounds were tested for antimicrobial activity against several bacteria and fungi by the broth microdilution method. The thiosemicarbazone and semicarbazone derivatives of lapachol exhibited antimicrobial activity against the bacteria Enterococcus faecalis and Staphylococcus aureus with minimal inhibitory concentrations (MICs) of 0.05 and 0.10 µmol/mL, respectively. The thiosemicarbazone and semicarbazone derivatives were also active against the pathogenic yeast Cryptococcus gattii (MICs of 0.10 and 0.20 µmol/mL, respectively). In addition, the lapachol thiosemicarbazone derivative was active against 11 clinical isolates of Paracoccidioides brasiliensis, with MICs ranging from 0.01-0.10 µmol/mL. The lapachol-derived thiosemicarbazone was not cytotoxic to normal cells at the concentrations that were active against fungi and bacteria. We synthesised, for the first time, thiosemicarbazone and semicarbazone derivatives of lapachol. The MICs for the lapachol-derived thiosemicarbazone against S. aureus, E. faecalis, C. gattii and several isolates of P. brasiliensis indicated that this compound has the potential to be developed into novel drugs to treat infections caused these microbes. PMID:23778660

Souza, Marina Azevêdo; Johann, Susana; Lima, Luciana Alves Rodrigues dos Santos; Campos, Fernanda Fraga; Mendes, Isolda Castro; Beraldo, Heloisa; de Souza-Fagundes, Elaine Maria; Cisalpino, Patrícia Silva; Rosa, Carlos Augusto; Alves, Tânia Maria de Almeida; de Sá, Nívea Pereira; Zani, Carlos Leomar

2013-01-01

403

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

404

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 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

2014-01-07

405

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

406

Permeability properties of peroxisomal membranes from yeasts.  

PubMed

We have studied the permeability properties of intact peroxisomes and purified peroxisomal membranes from two methylotrophic yeasts. After incorporation of sucrose and dextran in proteoliposomes composed of asolectin and peroxisomal membranes isolated from the yeasts Hansenula polymorpha and Candida boidinii a selective leakage of sucrose occurred indicating that the peroxisomal membranes were permeable to small molecules. Since the permeability of yeast peroxisomal membranes in vitro may be due to the isolation procedure employed, the osmotic stability of peroxisomes was tested during incubations of intact protoplasts in hypotonic media. Mild osmotic swelling of the protoplasts also resulted in swelling of the peroxisomes present in these cells but not in a release of their matrix proteins. The latter was only observed when the integrity of the cells was disturbed due to disruption of the cell membrane during further lowering of the concentration of the osmotic stabilizer. Stability tests with purified peroxisomes indicated that this leak of matrix proteins was not associated with the permeability to sucrose. Various attempts to mimic the in vivo situation and generate a proton motive force across the peroxisomal membranes in order to influence the permeability properties failed. Two different proton pumps were used for this purpose namely bacteriorhodopsin (BR) and reaction center-light-harvesting complex I (RCLH1 complex). After introduction of BR into the membrane of intact peroxisomes generation of a pH-gradient was not or barely detectable. Since this pump readily generated a pH-gradient in pure liposomes, these results strengthened the initial observations on the leakiness of the peroxisomal membrane fragments.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2339956

Douma, A C; Veenhuis, M; Sulter, G J; Waterham, H R; Verheyden, K; Mannaerts, G P; Harder, W

1990-01-01

407

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

408

Studying Functions of All Yeast Genes Simultaneously  

NASA Technical Reports Server (NTRS)

A method of studying the functions of all the genes of a given species of microorganism simultaneously has been developed in experiments on Saccharomyces cerevisiae (commonly known as baker's or brewer's yeast). It is already known that many yeast genes perform functions similar to those of corresponding human genes; therefore, by facilitating understanding of yeast genes, the method may ultimately also contribute to the knowledge needed to treat some diseases in humans. Because of the complexity of the method and the highly specialized nature of the underlying knowledge, it is possible to give only a brief and sketchy summary here. The method involves the use of unique synthetic deoxyribonucleic acid (DNA) sequences that are denoted as DNA bar codes because of their utility as molecular labels. The method also involves the disruption of gene functions through deletion of genes. Saccharomyces cerevisiae is a particularly powerful experimental system in that multiple deletion strains easily can be pooled for parallel growth assays. Individual deletion strains recently have been created for 5,918 open reading frames, representing nearly all of the estimated 6,000 genetic loci of Saccharomyces cerevisiae. Tagging of each deletion strain with one or two unique 20-nucleotide sequences enables identification of genes affected by specific growth conditions, without prior knowledge of gene functions. Hybridization of bar-code DNA to oligonucleotide arrays can be used to measure the growth rate of each strain over several cell-division generations. The growth rate thus measured serves as an index of the fitness of the strain.

Stolc, Viktor; Eason, Robert G.; Poumand, Nader; Herman, Zelek S.; Davis, Ronald W.; Anthony Kevin; Jejelowo, Olufisayo

2006-01-01

409

Genetic influences on translation in yeast.  

PubMed

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

2014-10-01

410

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

411

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

412

Metalloregulation of yeast membrane steroid receptor homologs  

PubMed Central

Zinc is an essential micronutrient that can also be toxic. An intricate mechanism exists in yeast that maintains cellular zinc within an optimal range. The centerpiece of this mechanism is the Zap1p protein, a transcription factor that senses zinc deficiency and responds by up-regulating genes involved in zinc metabolism. A microarray screen for novel Zap1p target genes suggested a role in zinc homeostasis for four homologous yeast genes. The expression of two of these genes, YDR492w and YOL002c, suggested direct regulation by Zap1p, whereas the expression of YOL002c and a third homologous gene, YOL101c, was induced by high zinc. YDR492w and YOL002c are confirmed to be direct Zap1p target genes. The induction of YOL002c and YOL101c by toxic metal ion exposure is shown to be mediated by the Mga2p hypoxia sensor. Furthermore, YOL101c is induced by deletion of the Aft1p iron-responsive transcription factor. These three genes, along with a fourth yeast homolog, YLR023c, have phenotypic effects on zinc tolerance and Zap1p activity. Because of their metalloregulation, zinc-related phenotypes, and highly conserved motifs containing potential metal-binding residues, this family has been renamed the IZH gene family (Implicated in Zinc Homeostasis). Furthermore, these genes are regulated by exogenous fatty acids, suggesting a dual role in lipid metabolism. The IZH genes encode membrane proteins that belong to a ubiquitous protein family that includes hemolysin III and vertebrate membrane steroid receptors. We propose that the IZH genes affect zinc homeostasis either directly or indirectly by altering sterol metabolism. PMID:15060275

Lyons, Thomas J.; Villa, Nancy Y.; Regalla, Lisa M.; Kupchak, Brian R.; Vagstad, Anna; Eide, David J.

2004-01-01

413

Formulation and evaluation of dried yeast tablets using different techniques  

Microsoft Academic Search

The aim of this study was to prepare and evaluate dried yeast tablets using both direct compression and dry granulation techniques in comparison with the conventional wet granulation as well as commercial product. Wet granulation technique is not favorable for producing the yeast tablets due to the problems of color darkening and the reduction of the fermentation power of the

Abdullah M. Al-Mohizea; Mahrous O. Ahmed; Fahad I. Al-jenoobi; Gamal M. Mahrous; Aly A. Abdel-Rahman

2007-01-01

414

Organelles on the move: insights from yeast vacuole inheritance  

Microsoft Academic Search

Organelle inheritance is one of several processes that occur during cell division. Recent studies on yeast vacuole inheritance have indicated rules that probably apply to most organelle-inheritance pathways. They have uncovered a molecular mechanism for membrane-cargo transport that is partially conserved from yeast to humans. They have also shown that the transport complex, which is composed of a molecular motor

Lois S. Weisman

2003-01-01

415

High-frequency transformation of the fission yeast Schizosaccharomyces pombe  

Microsoft Academic Search

The fission yeast, Schizosaccharomyces pombe, has been used extensively for genetic studies but until now it has not been utilized as a host organism for DNA cloning. Here we describe a method for high-frequency transformation of a leu 1- strain of this yeast with hybrid plasmids containing the Saccharomyces cerevisiae LEU 2+ gene, a bacterial plasmid and either the S.

David Beach; Paul Nurse

1981-01-01

416

Ultradian rhythms and clocks in plants and yeast  

Microsoft Academic Search

Studies of ultradian rhythms (<1 day) in plants and in yeasts provide insights into the temporal hierarchy of living organisms. Primarily a reflection of intracellular control circuits, special rhythms are temperature-compensated that have evolved as timekeepers. The best understood ultradian clock is that in yeast; it provides a timeframe for the coherent behaviour of biochemical activities from metabolic and membrane-associated

David Lloyd

2006-01-01

417

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

418

Abundant ribonucleotide incorporation into DNA by yeast replicative polymerases  

E-print Network

Abundant ribonucleotide incorporation into DNA by yeast replicative polymerases Stephanie A. Nick that the four rNTPs are in 36- to 190-fold molar excess over their corresponding dNTPs. During DNA synthesis in vitro using the physiological nucleoside triphosphate concentra- tions, yeast DNA polymerase , which

Burgers, Peter M.

419

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

E-print Network

New insights into treating Parkinson's from yeast, stem cell experiments By Carolyn Y. Johnson cells created from Parkinson's disease patients' stem cells. The work, described in a pair of studies problems of Parkinson's disease may seem tenuous at best, the researchers engineered the yeast

Sabatini, David M.

420

Improving industrial yeast strains: exploiting natural and artificial diversity  

PubMed Central

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

2014-01-01

421

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

422

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

423

Yeast biodiversity from oleic ecosystems: Study of their biotechnological properties  

Microsoft Academic Search

The aim of this study was to know the yeast biodiversity from fresh olive (Olea europaea L.) fruits, olive paste (crush olives) and olive pomace (solid waste) from Arbequina and Cornicabra varieties. Yeasts were isolated from fruits randomly harvested at various olive groves in the region of Castilla La Mancha (Spain). Olive paste and pomace, a byproduct of the processing

Sheila Romo-Sánchez; Milla Alves-Baffi; María Arévalo-Villena; Juan Úbeda-Iranzo; Ana Briones-Pérez

2010-01-01

424

Where does fission yeast sit on the tree of life?  

PubMed Central

The budding yeast Saccharomyces cerevisiae and the fission yeast Schizosaccharomyces pombe are as different from each other as either is from animals: their ancestors separated about 420 to 330 million years ago. Now that S. pombe is poised to join the post-genome era, its evolutionary position should become much clearer. PMID:11178233

Sipiczki, Matthias

2000-01-01

425

The ultrastructure of yeast: Cell wall structure and formation  

Microsoft Academic Search

Yeasts are unicellular eukaryotes, and are used widely as a model system in basic and applied field of life science, medicine, and biotechnology. The ultrastructure of yeast cells was first studied in 1957 and the techniques used have advanced greatly in the 40 years since then; an overview of these methods is first presented in this review. The ultrastructure of

Masako Osumi

1998-01-01

426

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

427

Overexpression of membrane proteins from higher eukaryotes in yeasts.  

PubMed

Heterologous expression and characterisation of the membrane proteins of higher eukaryotes is of paramount interest in fundamental and applied research. Due to the rather simple and well-established methods for their genetic modification and cultivation, yeast cells are attractive host systems for recombinant protein production. This review provides an overview on the remarkable progress, and discusses pitfalls, in applying various yeast host strains for high-level expression of eukaryotic membrane proteins. In contrast to the cell lines of higher eukaryotes, yeasts permit efficient library screening methods. Modified yeasts are used as high-throughput screening tools for heterologous membrane protein functions or as benchmark for analysing drug-target relationships, e.g., by using yeasts as sensors. Furthermore, yeasts are powerful hosts for revealing interactions stabilising and/or activating membrane proteins. We also discuss the stress responses of yeasts upon heterologous expression of membrane proteins. Through co-expression of chaperones and/or optimising yeast cultivation and expression strategies, yield-optimised hosts have been created for membrane protein crystallography or efficient whole-cell production of fine chemicals. PMID:25070595

Emmerstorfer, Anita; Wriessnegger, Tamara; Hirz, Melanie; Pichler, Harald

2014-09-01

428

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

429

Oxygen Stress: A Regulator of Apoptosis in Yeast  

Microsoft Academic Search

Oxygen radicals are important components of metazoan apoptosis. We have found that apoptosis can be induced in the yeast Saccharomyces cerevisiae by depletion of glutathione or by low external doses of H 2 O 2 . Cycloheximide prevents apoptotic death reveal- ing active participation of the cell. Yeast can also be triggered into apoptosis by a mutation in CDC48 or

Frank Madeo; Eleonore Fröhlich; Martin Ligr; Martin Grey; Stephan J. Sigrist; Dieter H. Wolf; Kai-Uwe Fröhlich

1999-01-01

430

ASCOMYCETOUS MITOSIS IN BASIDIOMYCETOUS YEASTS: ITS EVOLUTIONARY IMPLICATIONS  

Technology Transfer Automated Retrieval System (TEKTRAN)

In budding cells of ascomycetous yeasts, mitosis occurs in the parent, while in basidiomyceteous yeasts it occurs in the bud. However, in the basidiomycete Agaricostilbum pulcherrimum mitosis occurs in the parent and parent-bud junction. To test whether A. pulcherrimum has a novel mitotic pattern, i...

431

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

432

Opioid-like antinociceptive effects of oral administration of a lectin purified from the seeds of Canavalia brasiliensis.  

PubMed

The objective of this study was to evaluate the antinociceptive effects of a lectin from Canavalia brasiliensis (ConBr) when administered orally to murine models of chemical and thermal nociception. ConBr up to 100 mg/kg produced significant and dose-dependent antinociceptive effects: 81% reduction in abdominal writhing induced by 0.6% acetic acid; 26 and 52% reduction in early- and late-stage paw licking, respectively, induced by 2.5% formalin; and 155% increase in reaction latency (heightened thermal pain threshold). In all models, the antinociceptive effect was reversed by the lectin-binding carbohydrate ?-d-methyl-mannoside and by the nonselective opioid antagonist naloxone. The antinociceptive effect observed in the formalin test was inhibited by the ?-selective antagonist naltrindole and the ?-selective antagonist nor-binaltorphimine but not by the ?-selective antagonist cyprodime. In conclusion, when administered orally to Swiss mice, the ConBr lectin displayed antinociceptive activity, both peripheral and central, mediated by the opioid system and involving ?-and ?-receptors and the lectin domain. PMID:21895762

de Freitas Pires, Alana; Assreuy, Ana Maria Sampaio; Lopes, Érika Augusta Batista; Celedônio, Natália Rocha; Soares, Carlos Eduardo Alves; Rodrigues, Natália Velloso Fontenelle Camelo; Sousa, Paloma Leão; Benevides, Raquel Guimarães; Nagano, Celso Shiniti; Cavada, Benildo Sousa; Leal-Cardoso, José Henrique; Coelho-de-Souza, Andrelina Noronha; Santos, Cláudia Ferreira

2013-04-01

433

Complete Genome Sequence Analysis of Nocardia brasiliensis HUJEG-1 Reveals a Saprobic Lifestyle and the Genes Needed for Human Pathogenesis  

PubMed Central

Nocardia brasiliensis is an important etiologic agent of mycetoma. These bacteria live as a saprobe in soil or organic material and enter the tissue via minor trauma. Mycetoma is characterized by tumefaction and the production of fistula and abscesses, with no spontaneous cure. By using mass sequencing, we determined the complete genomic nucleotide sequence of the bacteria. According to our data, the genome is a circular chromosome 9,436,348-bp long with 68% G+C content that encodes 8,414 proteins. We observed orthologs for virulence factors, a higher number of genes involved in lipid biosynthesis and catabolism, and gene clusters for the synthesis of bioactive compounds, such as antibiotics, terpenes, and polyketides. An in silico analysis of the sequence supports the conclusion that the bacteria acquired diverse genes by horizontal transfer from other soil bacteria, even from eukaryotic organisms. The genome composition reflects the evolution of bacteria via the acquisition of a large amount of DNA, which allows it to survive in new ecological niches, including humans. PMID:23755230

Vera-Cabrera, Lucio; Ortiz-Lopez, Rocio; Elizondo-Gonzalez, Ramiro; Ocampo-Candiani, Jorge

2013-01-01

434

Agaricus bisporus and Agaricus brasiliensis (1?6)-?-D-glucans show immunostimulatory activity on human THP-1 derived macrophages.  

PubMed

The (1?6)-?-D-glucans from Agaricus bisporus and Agaricus brasiliensis were purified to evaluate their effects on the innate immune system. THP-1 macrophages were used to investigate the induction of the expression of TNF-?, IL1?, and COX-2 by RT-PCR. The purification of the polysaccharides gave rise to fractions containing 96-98% of glucose. The samples were analyzed by GC-MS, HPSEC and (13)C NMR, which confirmed the presence of homogeneous (1?6)-?-D-glucans. The ?-glucans were incubated with THP-1 derived macrophages, for 3 h and 6 h to evaluate their effects on the expression of pro-inflammatory genes. Both ?-glucans stimulated the expression of such genes as much as the pro-inflammatory control (LPS). When the cells were incubated with LPS+?-glucan, a significant inhibition of the expression of IL-1? and COX-2 was observed for both treatments after 3 h of incubation. By the results, we conclude that the (1?6)-?-D-glucans present an immunostimulatory activity when administered to THP-1 derived macrophages. PMID:23544515

Smiderle, Fhernanda R; Alquini, Giovana; Tadra-Sfeir, Michelle Z; Iacomini, Marcello; Wichers, Harry J; Van Griensven, Leo J L D

2013-04-15

435

Adsorption of Bismark Brown dye on activated carbons prepared from rubberwood sawdust (Hevea brasiliensis) using different activation methods.  

PubMed

Hevea brasiliensis or rubberwood tree, as it is commonly known finds limited use once the latex has been tapped. The sawdust of this tree is chosen to ascertain it viability as a precursor for activation. The carbons thus obtained were characterized in terms of iodine, methylene blue number and surface area. The best carbon in each method was utilized to study the adsorption of Bismark Brown, a dye used in the leather industry. Adsorption equilibrium studies were carried out with the synthetic solutions of the dye, at room temperature (298 K). Equilibrium data are fitted with the Langmuir and the Freundlich isotherms models for the system. The effects of contact time, adsorbent dosage and initial dye concentrations on sorption capacit