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Sample records for aspergillus nidulans genome

  1. Analysis of Aspergillus nidulans metabolism at the genome-scale

    Directory of Open Access Journals (Sweden)

    Nielsen Jens

    2008-04-01

    Full Text Available Abstract Background Aspergillus nidulans is a member of a diverse group of filamentous fungi, sharing many of the properties of its close relatives with significance in the fields of medicine, agriculture and industry. Furthermore, A. nidulans has been a classical model organism for studies of development biology and gene regulation, and thus it has become one of the best-characterized filamentous fungi. It was the first Aspergillus species to have its genome sequenced, and automated gene prediction tools predicted 9,451 open reading frames (ORFs in the genome, of which less than 10% were assigned a function. Results In this work, we have manually assigned functions to 472 orphan genes in the metabolism of A. nidulans, by using a pathway-driven approach and by employing comparative genomics tools based on sequence similarity. The central metabolism of A. nidulans, as well as biosynthetic pathways of relevant secondary metabolites, was reconstructed based on detailed metabolic reconstructions available for A. niger and Saccharomyces cerevisiae, and information on the genetics, biochemistry and physiology of A. nidulans. Thereby, it was possible to identify metabolic functions without a gene associated, and to look for candidate ORFs in the genome of A. nidulans by comparing its sequence to sequences of well-characterized genes in other species encoding the function of interest. A classification system, based on defined criteria, was developed for evaluating and selecting the ORFs among the candidates, in an objective and systematic manner. The functional assignments served as a basis to develop a mathematical model, linking 666 genes (both previously and newly annotated to metabolic roles. The model was used to simulate metabolic behavior and additionally to integrate, analyze and interpret large-scale gene expression data concerning a study on glucose repression, thereby providing a means of upgrading the information content of experimental data

  2. Analysis of Aspergillus nidulans metabolism at the genome-scale

    DEFF Research Database (Denmark)

    David, Helga; Ozcelik, İlknur Ş; Hofmann, Gerald;

    2008-01-01

    function. Results: In this work, we have manually assigned functions to 472 orphan genes in the metabolism of A. nidulans, by using a pathway-driven approach and by employing comparative genomics tools based on sequence similarity. The central metabolism of A. nidulans, as well as biosynthetic pathways of...

  3. The 2008 update of the Aspergillus nidulans genome annotation: A community effort

    DEFF Research Database (Denmark)

    Wortman, Jennifer Russo; Gilsenan, Jane Mabey; Joardar, Vinita;

    2009-01-01

    The identification and annotation of protein-coding genes is one of the primary goals of whole-genome sequencing projects, and the accuracy of predicting the primary protein products of gene expression is vital to the interpretation of the available data and the design of downstream functional...... applications. Nevertheless, the comprehensive annotation of eukaryotic genomes remains a considerable challenge. Many genomes submitted to public databases, including those of major model organisms, contain significant numbers of wrong and incomplete gene predictions. We present a community-based reannotation...... of the Aspergillus nidulans genome with the primary goal of increasing the number and quality of protein functional assignments through the careful review of experts in the field of fungal biology....

  4. Post-genomic insights into the plant polysaccharide degradation potential of Aspergillus nidulans and comparison to Aspergillus niger and Aspergillus oryzae

    DEFF Research Database (Denmark)

    Coutinho, Pedro M.; Andersen, Mikael Rørdam; Kolenova, Katarina; vanKuyk, Patricia A.; Benoit, Isabelle; Gruben, Birgit S.; Trejo-Aguilar, Blanca; Visser, Hans; van Solingen, Piet; Pakula, Tiina; Seiboth, Bernard; Battaglia, Evy; Aguilar-Osorio, Guillermo; de Jong, Jan F.; Ohm, Robin A.; Aguilar, Mariana; Henrissat, Bernard; Nielsen, Jens; Stålbrand, Henrik; de Vries, Ronald P.

    The plant polysaccharide degradative potential of Aspergillus nidulans was analysed in detail and compared to that of Aspergillus niger and Aspergillus oryzae using a combination of bioinformatics, physiology and transcriptomics. Manual verification indicated that 28.4% of the A. nidulans ORFs...

  5. Mapping of polyketide biosynthesis pathways in Aspergillus nidulans using a genome wide PKS gene deletion library

    DEFF Research Database (Denmark)

    Larsen, Thomas Ostenfeld; Rank, Christian; Klejnstrup, Marie Louise;

    In order to map new links between PKS genes and their products in Aspergillus nidulans we have systematically deleted all thirty-two individual genes predicted to encode polyketide synthases in this model organism. This number greatly exceeds the number of currently known PKs calling for new...

  6. Asexual Sporulation in Aspergillus nidulans

    OpenAIRE

    Adams, Thomas H; Wieser, Jenny K.; Yu, Jae-Hyuk

    1998-01-01

    The formation of mitotically derived spores, called conidia, is a common reproductive mode in filamentous fungi, particularly among the large fungal class Ascomycetes. Asexual sporulation strategies are nearly as varied as fungal species; however, the formation of conidiophores, specialized multicellular reproductive structures, by the filamentous fungus Aspergillus nidulans has emerged as the leading model for understanding the mechanisms that control fungal sporulation. Initiation of A. nid...

  7. The transmission of cytoplasmic genes in Aspergillus nidulans.

    OpenAIRE

    Coenen, A

    1997-01-01

    IntroductionThis manuscript concerns the spread of selfish cytoplasmic genes in the fungus Aspergillus nidulans. A.nidulans is a common soil fungus that grows vegetatively by forming a network (mycelium) of hyphae and reproduces via sexual ascospores and asexual conidiospores. Cytoplasmic genes are genes that are located in the cell cytoplasm and not in the cell nucleus where most genes are situated. The cytoplasmic genes investigated in this research are the genomes of mitochondria and virus...

  8. A genome-wide polyketide synthase deletion library uncovers novel genetic links to polyketides and meroterpenoids in Aspergillus nidulans

    DEFF Research Database (Denmark)

    Nielsen, Michael Lynge; Nielsen, Jakob Blæsbjerg; Rank, Christian; Klejnstrup, Marie Louise; Holm, Dorte Koefoed; Brogaard, Katrine Husted; Hansen, Bjarne Gram; Frisvad, Jens Christian; Larsen, Thomas Ostenfeld; Mortensen, Uffe Hasbro

    2011-01-01

    Fungi possess an advanced secondary metabolism that is regulated and coordinated in a complex manner depending on environmental challenges. To understand this complexity, a holistic approach is necessary. We initiated such an analysis in the important model fungus Aspergillus nidulans by...

  9. Genetics of Polyketide Metabolism in Aspergillus nidulans

    DEFF Research Database (Denmark)

    Klejnstrup, Marie L.; Frandsen, Rasmus John Normand; Holm, Dorte Koefoed;

    2012-01-01

    including polyketides. The majority of genes required for production of these metabolites are mostly organized in gene clusters, which often are silent or barely expressed under laboratory conditions, making discovery and analysis difficult. Fortunately, the genome sequences of several filamentous fungi are...... publicly available, greatly facilitating the establishment of links between genes and metabolites. This review covers the attempts being made to trigger the activation of polyketide metabolism in the fungal model organism Aspergillus nidulans. Moreover, it will provide an overview of the pathways where ten...... polyketide synthase genes have been coupled to polyketide products. Therefore, the proposed biosynthesis of the following metabolites will be presented; naphthopyrone, sterigmatocystin, aspyridones, emericellamides, asperthecin, asperfuranone, monodictyphenone/emodin, orsellinic acid, and the austinols....

  10. Chemical analysis of a genome wide polyketide synthase gene deletion library in Aspergillus nidulans

    DEFF Research Database (Denmark)

    Larsen, Thomas Ostenfeld; Klejnstrup, Marie Louise; Nielsen, Jakob Blæsbjerg;

    predicted to encode polyketide synthases have been individually been deleted. This presentation will highlight our recent linking of secondary metabolites in A. nidulans to genes, and in particular describe some recent work on characterization of ANID_6448 and associated genes responsible for biosynthesis...

  11. L-histidine utilization in Aspergillus nidulans.

    OpenAIRE

    Polkinghorne, M A; Hynes, M J

    1982-01-01

    Histidase activity rather than uptake of L-histidine is the limiting factor for the utilization of histidine as the sole nitrogen source for Aspergillus nidulans. Histidine cannot act as the sole carbon source, and evidence is presented indicating that this is attributable to an inability to convert histidine to L-glutamate in vivo. It has been shown that this fungus lacks an active urocanase enzyme and that histidine is quantitatively converted to urocanate, which accumulates in the extracel...

  12. Genetics of Polyketide Metabolism in Aspergillus nidulans

    Directory of Open Access Journals (Sweden)

    Marie L. Klejnstrup

    2012-01-01

    Full Text Available Secondary metabolites are small molecules that show large structural diversity and a broad range of bioactivities. Some metabolites are attractive as drugs or pigments while others act as harmful mycotoxins. Filamentous fungi have the capacity to produce a wide array of secondary metabolites including polyketides. The majority of genes required for production of these metabolites are mostly organized in gene clusters, which often are silent or barely expressed under laboratory conditions, making discovery and analysis difficult. Fortunately, the genome sequences of several filamentous fungi are publicly available, greatly facilitating the establishment of links between genes and metabolites. This review covers the attempts being made to trigger the activation of polyketide metabolism in the fungal model organism Aspergillus nidulans. Moreover, it will provide an overview of the pathways where ten polyketide synthase genes have been coupled to polyketide products. Therefore, the proposed biosynthesis of the following metabolites will be presented; naphthopyrone, sterigmatocystin, aspyridones, emericellamides, asperthecin, asperfuranone, monodictyphenone/emodin, orsellinic acid, and the austinols.

  13. The transmission of cytoplasmic genes in Aspergillus nidulans.

    NARCIS (Netherlands)

    Coenen, A.

    1997-01-01

    IntroductionThis manuscript concerns the spread of selfish cytoplasmic genes in the fungus Aspergillus nidulans. A.nidulans is a common soil fungus that grows vegetatively by forming a network (mycelium) of hyphae and reproduces via sexual ascospores and asexual conidiospores. Cytop

  14. Overexpression of a novel endogenous NADH kinase in Aspergillus nidulans enhances growth

    DEFF Research Database (Denmark)

    Panagiotou, Gianni; Grotkjær, Thomas; Hofmann, Gerald;

    2009-01-01

    The complete genome sequence of the filamentous fungi Aspergillus nidulans has paved the way for fundamental research on this industrially important species. To the best of our knowledge, this is the first time a gene encoding for ATP-dependent NADH kinase (ATP: NADH 2'-phosphotransferase, EC 2.7...

  15. Developmental regulation of laccase levels in Aspergillus nidulans.

    OpenAIRE

    Law, D. J.; Timberlake, W E

    1980-01-01

    Asexual spores (conidia) of Aspergillus nidulans contain a dark green pigment which is not present in other cell types. Synthesis of this pigment is catalyzed, in part, by a developmentally controlled p-diphenol oxidase, or laccase, encoded at the gamma A genetic locus (A. J. Clutterbuck, J. Gen. Microbiol. 70:423-435, 1972). We have investigated the mechanisms regulating expression of the gamma A gene of A. nidulans. Vegetative hyphae grown in submerged culture lacked detectable laccase enzy...

  16. Apical control of conidiation in Aspergillus nidulans.

    Science.gov (United States)

    Oiartzabal-Arano, Elixabet; Perez-de-Nanclares-Arregi, Elixabet; Espeso, Eduardo A; Etxebeste, Oier

    2016-05-01

    The infection cycle of filamentous fungi consists of two main stages: invasion (growth) and dispersion (development). After the deposition of a spore on a host, germination, polar extension and branching of vegetative cells called hyphae allow a fast and efficient invasion. Under suboptimal conditions, genetic reprogramming of hyphae results in the generation of asexual spores, allowing dissemination to new hosts and the beginning of a new infection cycle. In the model filamentous fungus Aspergillus nidulans, asexual development or conidiation is induced by the upstream developmental activation (UDA) pathway. UDA proteins transduce signals from the tip, the polarity site of hyphae, to nuclei, where developmental programs are transcriptionally activated. The present review summarizes the current knowledge on this tip-to-nucleus communication mechanism, emphasizing its dependence on hyphal polarity. Future approaches to the topic will also be suggested, as stimulating elements contributing to the understanding of how apical signals are coupled with the transcriptional control of development and pathogenesis in filamentous fungi. PMID:26782172

  17. Cloning and analysis of the positively acting regulatory gene amdR from Aspergillus nidulans.

    OpenAIRE

    Andrianopoulos, A; Hynes, M J

    1988-01-01

    The positively acting regulatory gene amdR of Aspergillus nidulans coordinately regulates the expression of four unlinked structural genes involved in acetamide (amdS), omega amino acid (gatA and gabA), and lactam (lamA) catabolism. By the use of DNA-mediated transformation of A. nidulans, the amdR regulatory gene was cloned from a genomic cosmid library. Southern blot analysis of DNA from various loss-of-function amdR mutants revealed the presence of four detectable DNA rearrangements, inclu...

  18. The Spt-Ada-Gcn5 Acetyltransferase (SAGA complex in Aspergillus nidulans.

    Directory of Open Access Journals (Sweden)

    Paraskevi Georgakopoulos

    Full Text Available A mutation screen in Aspergillus nidulans uncovered mutations in the acdX gene that led to altered repression by acetate, but not by glucose. AcdX of A. nidulans is highly conserved with Spt8p of Saccharomyces cerevisiae, and since Spt8p is a component of the Spt-Ada-Gcn5 Acetyltransferase (SAGA complex, the SAGA complex may have a role in acetate repression in A. nidulans. We used a bioinformatic approach to identify genes encoding most members of the SAGA complex in A. nidulans, and a proteomic analysis to confirm that most protein components identified indeed exist as a complex in A. nidulans. No apparent compositional differences were detected in mycelia cultured in acetate compared to glucose medium. The methods used revealed apparent differences between Yeast and A. nidulans in the deubiquitination (DUB module of the complex, which in S. cerevisiae consists of Sgf11p, Sus1p, and Ubp8p. Although a convincing homologue of S. cerevisiae Ubp8p was identified in the A. nidulans genome, there were no apparent homologues for Sus1p and Sgf11p. In addition, when the SAGA complex was purified from A. nidulans, members of the DUB module were not co-purified with the complex, indicating that functional homologues of Sus1p and Sgf11p were not part of the complex. Thus, deubiquitination of H2B-Ub in stress conditions is likely to be regulated differently in A. nidulans compared to S. cerevisiae.

  19. Genetic Analysis of the TOR Pathway in Aspergillus nidulans

    OpenAIRE

    Fitzgibbon, Gregory J.; Morozov, Igor Y; Jones, Meriel G.; Caddick, Mark X.

    2005-01-01

    We identified five genes encoding components of the TOR signaling pathway within Aspergillus nidulans. Unlike the situation in Saccharomyces cerevisiae, there is only a single Tor kinase, as in plant and animal systems, and mutant phenotypes suggest that the TOR pathway plays only a minor role in regulating nitrogen metabolism.

  20. Chromosomal duplication strains of Aspergillus nidulans and their instability

    International Nuclear Information System (INIS)

    Strains of Aspergillus nidulans with chromosomal duplication were obtained after gamma irradiation followed by crossing of the translocated strains with normal strains. From 20 analysed colonies, 12 have shown translocations induced by irradiation. Segregants from four of these translocation strains crossed to normal strains have shown to be unstable although presenting normal morphology. Two segregants were genetically analysed. The first one has shown a duplication of part of linkage groups VIII and the second one presented a duplication of a segment of linkage group V. These new duplication strains in A. nidulans open new perspectives of a more detailed study of the instability phenomenon in this fungus. (Author)

  1. Checkpoint Defects Leading to Premature Mitosis Also Cause Endoreplication of DNA in Aspergillus nidulans

    OpenAIRE

    De Souza, Colin P. C.; Ye, Xiang S.; Osmani, Stephen A.

    1999-01-01

    The G2 DNA damage and slowing of S-phase checkpoints over mitosis function through tyrosine phosphorylation of NIMXcdc2 in Aspergillus nidulans. We demonstrate that breaking these checkpoints leads to a defective premature mitosis followed by dramatic rereplication of genomic DNA. Two additional checkpoint functions, uvsB and uvsD, also cause the rereplication phenotype after their mutation allows premature mitosis in the presence of low concentrations of hydroxyurea. uvsB is shown to encode ...

  2. crnA encodes a nitrate transporter in Aspergillus nidulans

    OpenAIRE

    Unkles, S.E.; Hawker, K L; Grieve, C; Campbell, E I; Montague, P.; Kinghorn, J R

    1995-01-01

    The nucleotide sequence of the Aspergillus nidulans crnA gene for the transport of the anion nitrate has been determined. The crnA gene specifies a predicted polypeptide of 483 amino acids (molecular weight 51,769). A hydropathy plot suggests that this polypeptide has 10 membrane-spanning helices with an extensive hydrophilic region between helices six and seven. No striking homology was observed between the crnA protein and other reported membrane proteins of either prokaryotic or eukaryotic...

  3. Clustering of spore-specific genes in Aspergillus nidulans.

    OpenAIRE

    Orr, W C; Timberlake, W E

    1982-01-01

    We have investigated the chromosomal organization of genes that are expressed specifically in the asexual spores (conidia) of the Ascomycete fungus Aspergillus nidulans, using two experimental approaches. In the first, 30 different recombinant clones, containing long nuclear DNA inserts and at least one spore-specific gene, were selected randomly. The total number of spore-specific genes present in each clone was then determined by RNA blot analysis. In the second approach, several chromosoma...

  4. Mutantes letais termossensíveis em Aspergillus nidulans Temperature sensitive lethal mutants in Aspergillus nidulans

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    P. C. de Oliveira

    1975-01-01

    Full Text Available Amostras termossensíveis (42ºC de A. nidulans foram obtidas pela irradiação com U.V. Dentre 18 mutantes termossensíveis, 3 demonstraram que o determinante da termossensibilidade era causado por efeitos associados com o núcleo e foram selecionados para estudos posteriores. Foram sintetizados diplóides entre amostras normais e os três mutantes (mais um exibindo letalidade 42ºC e foi verificada uma completa recessividade em todos os casos. Para fins comparativos forma feitas tentativas para o alelo correspondente, mostraram resultados bastante diferentes quando experimentados em diferentes tempos de incubação inicial a 37ºC e depois transferidos para 41ºC. Os herocários praticamente não apresentaram resposta adaptativa às mudanças de temperatura. A ligeira diferença de comportamento heterocários: heterozigoto provavelmente é resultante do efeito de dosagem. Os resultados reafirmam e oferecem confiança na estabilidade dos heterocários quando em condições constantes de meio.Temperature sensitive strains (42ºC of Aspergillus nidulans were obtaines by U.V. irradiation. The mutant alleles had not been located and among 18 thermosensitive mutants theree gave clear evidence that the determinant of thermosensitivity was caused by effects associated with the nucleus and were selected for further studies. Diploids have been synthesised between normal straisn and the three latter variants eschibiting lethality at 42ºC and a complete recessivity of the character in each case was shown. For comparative purposes attempts were made to find instances of "adaptation". Nutritionally balanced heterokaryons, between tsl and the wild tipe strains for the corresponding alleles had show quite different results when experience on increasing initial incutation time at 37ºC ant then were transfered to 41ºC. Heterokaryons had not showed adaptative reponse to the changes of temperature. The heterokaryon: heterozygote slight difference of behavior

  5. Regulation of Development in Aspergillus nidulans and Aspergillus fumigatus

    OpenAIRE

    Yu, Jae-Hyuk

    2010-01-01

    Members of the genus Aspergillus are the most common fungi and all reproduce asexually by forming long chains of conidiospores (or conidia). The impact of various Aspergillus species on humans ranges from beneficial to harmful. For example, several species including Aspergillus oryzae and Aspergillus niger are used in industry for enzyme production and food processing. In contrast, Aspergillus flavus produce the most potent naturally present carcinogen aflatoxins, which contaminate various pl...

  6. Reversion in variants from a duplication strain of Aspergillus nidulans

    International Nuclear Information System (INIS)

    Strains of Aspergillus nidulans with a chromosome segment in duplicate, one in normal position and one translocated to another chromosome, are unstable at mitosis. In addition to variants which result from deletions in either of the duplicate segments, which usually have improved morphology, they produce variants with deteriorated morphology. Three deteriorated variants reverted frequently to parental type morphology, both spontaneously and after ultra-violet treatment. Of six reversions analysed genetically, five were due to suppressors and one was probably due to back mutation. The suppressors segregated as single genes and were not linked to the mutation which they suppress. The instability of these so-called 'deteriorated' variants is discussed in relation to mitotic instability phenomena in A. nidulans. (orig.)

  7. Kinetics of the nuclear division cycle of Aspergillus nidulans.

    OpenAIRE

    Bergen, L G; Morris, N R

    1983-01-01

    We have analyzed the cell cycle kinetics of Aspergillus nidulans by using the DNA synthesis inhibitor hydroxyurea (HU) and a temperature-sensitive cell cycle mutant nimT that blocks in G2. HU rapidly inhibits DNA synthesis (S), and as a consequence progression beyond S to mitosis (M) is blocked. Upon removal of HU the inhibition is rapidly reversible. Conidia (asexual spores) of nimT were germinated at restrictive temperature to synchronize germlings in G2 and then downshifted to permissive t...

  8. Novel Sexual-Cycle-Specific Gene Silencing in Aspergillus nidulans

    OpenAIRE

    Czaja, Wioletta; Miller, Karen Y.; Bruce L. Miller

    2013-01-01

    We report a novel sexual-cycle-specific gene-silencing system in the genetic model Aspergillus nidulans. Duplication of the mating type matAHMG gene in this haploid organism triggers Mat-induced silencing (MatIS) of both endogenous and transgenic matA genes, eliminates function of the encoded SRY structural ortholog, and results in formation of barren fruiting bodies. MatIS is spatiotemporally restricted to the prezygotic stage of the sexual cycle and does not interfere with vegetative growth...

  9. Increase in mitotic recombination in diploid cells of Aspergillus nidulans in response to ethidium bromide

    Directory of Open Access Journals (Sweden)

    Tânia C.A. Becker

    2003-01-01

    Full Text Available Ethidium bromide (EB is an intercalating inhibitor of topoisomerase II and its activities are related to chemotherapeutic drugs used in anti-cancer treatments. EB promotes several genotoxic effects in exposed cells by stabilising the DNA-enzyme complex. The recombinagenic potential of EB was evaluated in our in vivo study by the loss of heterozygosity of nutritional markers in diploid Aspergillus nidulans cells through Homozygotization Index (HI. A DNA repair mutation, uvsZ and a chromosome duplication DP (II-I were introduced in the genome of tested cells to obtain a sensitive system for the recombinagenesis detection. EB-treated diploid cells had HI values significantly greater than the control at both concentrations (4.0 x 10-3 and 5.0 x 10-3 mM. Results indicate that the intercalating agent is potentially capable of inducing mitotic crossing-over in diploid A. nidulans cells.

  10. The nucleation of microtubules in Aspergillus nidulans germlings

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    Andrade-Monteiro Cristina de

    1999-01-01

    Full Text Available Microtubules are filaments composed of dimers of alpha- and beta-tubulins, which have a variety of functions in living cells. In fungi, the spindle pole bodies usually have been considered to be microtubule-organizing centers. We used the antimicrotubule drug Benomyl in block/release experiments to depolymerize and repolymerize microtubules in Aspergillus nidulans germlings to learn more about the microtubule nucleation process in this filamentous fungus. Twenty seconds after release from Benomyl short microtubules were formed from several bright (immunofluorescent dots distributed along the germlings, suggesting that microtubule nucleation is randomly distributed in A. nidulans germlings. Since nuclear movement is dependent on microtubules in A. nidulans we analyzed whether mutants defective in nuclear distribution along the growing hyphae (nud mutants have some obvious microtubule defect. Cytoplasmic, astral and spindle microtubules were present and appeared to be normal in all nud mutants. However, significant changes in the percentage of short versus long mitotic spindles were observed in nud mutants. This suggests that some of the nuclei of nud mutants do not reach the late stage of cell division at normal temperatures.

  11. Two divergent catalase genes are differentially regulated during Aspergillus nidulans development and oxidative stress.

    OpenAIRE

    Kawasaki, L; Wysong, D; Diamond, R.; Aguirre, J.

    1997-01-01

    Catalases are ubiquitous hydrogen peroxide-detoxifying enzymes that are central to the cellular antioxidant response. Of two catalase activities detected in the fungus Aspergillus nidulans, the catA gene encodes the spore-specific catalase A (CatA). Here we characterize a second catalase gene, identified after probing a genomic library with catA, and demonstrate that it encodes catalase B. This gene, designated catB, predicts a 721-amino-acid polypeptide (CatB) showing 78% identity to an Aspe...

  12. Velvet-mediated repression of β-glucan synthesis in Aspergillus nidulans spores

    OpenAIRE

    Hee-Soo Park; Yeong Man Yu; Mi-Kyung Lee; Pil Jae Maeng; Sun Chang Kim; Jae-Hyuk Yu

    2015-01-01

    Beta-glucans are a heterologous group of fibrous glucose polymers that are a major constituent of cell walls in Ascomycetes and Basidiomycetes fungi. Synthesis of β (1,3)- and (1,6)-glucans is coordinated with fungal cell growth and development, thus, is under tight genetic regulation. Here, we report that β-glucan synthesis in both asexual and sexual spores is turned off by the NF-kB like fungal regulators VosA and VelB in Aspergillus nidulans. Our genetic and genomic analyses have revealed ...

  13. Genetic control of mutation process in Aspergillus nidulans

    International Nuclear Information System (INIS)

    The frequency of UV-induced morphological mutations, the resistance to methyl green and rava → rava+ reversions have been studied in 6 uvs mutants of Aspergillus nidulans. It is shown that in all the uvs mutants the induction curves of different mutation types have a characteristic form with a maximum and a decrease in the mutation number (per number of survived cells) at high UV doses. Maxima of the induction of one mutation type in different uvs strains have been observed at different UV doses (and different survival). Comparative frequencies of the induction of different mutation types are different in different uvs strains. Uvs mutations are found which result in a sharp increase (uvs 19) or decrease down to complete absence (uvs12) or the induction of all the mutation types and mutations (uvs2, 20sup(a), 20sup(b), 26) specifically affecting the induction frequency of certain mutation types. It is concluded that UV-induced mutations in Aspergillus nidulans originate not only during postreplicative recombinative reparation, but also at other reparation ways, possibly, following excision

  14. Branching is coordinated with mitosis in growing hyphae of Aspergillus nidulans

    DEFF Research Database (Denmark)

    Dynesen, Jens Østergaard; Nielsen, Jens

    2003-01-01

    Filamentous fungi like Aspergillus nidulans can effectively colonize their surroundings by the formation of new branches along the existing hyphae. While growth conditions, chemical perturbations, and mutations affecting branch formation have received great attention during the last decades, the ...

  15. Human Leukocytes Kill Aspergillus nidulans by Reactive Oxygen Species-Independent Mechanisms▿

    OpenAIRE

    Henriet, Stefanie S. V.; Hermans, Peter W. M.; Verweij, Paul E.; Simonetti, Elles; Holland, Steven M.; Sugui, Janyce A.; Kwon-Chung, Kyung J.; Warris, Adilia

    2010-01-01

    Invasive aspergillosis is a major threat for patients suffering from chronic granulomatous disease (CGD). Although Aspergillus fumigatus is the most commonly encountered Aspergillus species, the presence of A. nidulans appears to be disproportionately high in CGD patients. The purpose of this study was to investigate the involvement of the NADPH oxidase and the resulting reactive oxygen species (ROS) in host defense against fungi and to clarify their relationship toward A. nidulans. Murine CG...

  16. VelC positively controls sexual development in Aspergillus nidulans.

    Directory of Open Access Journals (Sweden)

    Hee-Soo Park

    Full Text Available Fungal development and secondary metabolism is intimately associated via activities of the fungi-specific velvet family proteins including VeA, VosA, VelB and VelC. Among these, VelC has not been characterized in Aspergillus nidulans. In this study, we characterize the role of VelC in asexual and sexual development in A. nidulans. The velC mRNA specifically accumulates during the early phase of sexual development. The deletion of velC leads to increased number of conidia and reduced production of sexual fruiting bodies (cleistothecia. In the velC deletion mutant, mRNA levels of the brlA, abaA, wetA and vosA genes that control sequential activation of asexual sporulation increase. Overexpression of velC causes increased formation of cleistothecia. These results suggest that VelC functions as a positive regulator of sexual development. VelC is one of the five proteins that physically interact with VosA in yeast two-hybrid and GST pull down analyses. The ΔvelC ΔvosA double mutant produced fewer cleistothecia and behaved similar to the ΔvosA mutant, suggesting that VosA is epistatic to VelC in sexual development, and that VelC might mediate control of sex through interacting with VosA at specific life stages for sexual fruiting.

  17. Fatty acid composition of oil synthesized by Aspergillus nidulans.

    Science.gov (United States)

    Sharma, N D; Mathur, J M; Saxena, B S; Sen, K

    1981-01-01

    The filamentous fungus Aspergillus nidulans Eidam strain 300 was found to be capable of synthesizing 24.9% oil or remarkably low free fatty acidity, in a chemically defined medium with 34% glucose as sole carbon source. although the total content of oil synthesized was less, utilization of the carbon source is better as shown by the high (8.4) fat coefficient. The major component fatty acids of the oil were palmitic, stearic, oleic and linoleic and are influenced by the source of carbon. Palmitoleic acid is present in traces, confirming thereby the general observation that high oil formers produce oil of low hexadecenoic acid content. The relatively high stearic acid content of the oil distinguishes it from those of other microorganisms and resembles the oil produced by certain tropical plants, such as Madhuca latifolia. PMID:7026394

  18. Characterization of the aodA, dnmA, mnSOD and pimA genes in Aspergillus nidulans.

    Science.gov (United States)

    Leiter, Éva; Park, Hee-Soo; Kwon, Nak-Jung; Han, Kap-Hoon; Emri, Tamás; Oláh, Viktor; Mészáros, Ilona; Dienes, Beatrix; Vincze, János; Csernoch, László; Yu, Jae-Hyuk; Pócsi, István

    2016-01-01

    Mitochondria play key roles in cellular energy generation and lifespan of most eukaryotes. To understand the functions of four nuclear-encoded genes predicted to be related to the maintenance of mitochondrial morphology and function in Aspergillus nidulans, systematic characterization was carried out. The deletion and overexpression mutants of aodA, dnmA, mnSOD and pimA encoding alternative oxidase, dynamin related protein, manganese superoxide dismutase and Lon protease, respectively, were generated and examined for their growth, stress tolerances, respiration, autolysis, cell death, sterigmatocystin production, hyphal morphology and size, and mitochondrial superoxide production as well as development. Overall, genetic manipulation of these genes had less effect on cellular physiology and ageing in A. nidulans than that of their homologs in another fungus Podospora anserina with a well-characterized senescence. The observed interspecial phenotypic differences can be explained by the dissimilar intrinsic stabilities of the mitochondrial genomes in A. nidulans and P. anserina. Furthermore, the marginally altered phenotypes observed in A. nidulans mutants indicate the presence of effective compensatory mechanisms for the complex networks of mitochondrial defense and quality control. Importantly, these findings can be useful for developing novel platforms for heterologous protein production, or on new biocontrol and bioremediation technologies based on Aspergillus species. PMID:26846452

  19. An Acidic Thermostable Recombinant Aspergillus nidulans Endoglucanase Is Active towards Distinct Agriculture Residues

    OpenAIRE

    Marcio Jose Poças-Fonseca; Ildinete Silva-Pereira; Cynthia Maria Kyaw; Edivaldo Ximenes Ferreira Filho; Fabrícia Paula de Faria; Gilvan Caetano Duarte; Marciano Regis Rubini; Thiago Machado Mello-de-Sousa; Eveline Queiroz de Pinho Tavares

    2013-01-01

    Aspergillus nidulans is poorly exploited as a source of enzymes for lignocellulosic residues degradation for biotechnological purposes. This work describes the A. nidulans Endoglucanase A heterologous expression in Pichia pastoris, the purification and biochemical characterization of the recombinant enzyme. Active recombinant endoglucanase A (rEG A) was efficiently secreted as a 35 kDa protein which was purified through a two-step chromatography procedure. The highest enzyme activity was dete...

  20. The Role, Interaction and Regulation of the Velvet Regulator VelB in Aspergillus nidulans

    OpenAIRE

    Park, Hee-Soo; Ni, Min; Jeong, Kwang Cheol; Kim, Young Hwan; Yu, Jae-Hyuk

    2012-01-01

    The multifunctional regulator VelB physically interacts with other velvet regulators and the resulting complexes govern development and secondary metabolism in the filamentous fungus Aspergillus nidulans. Here, we further characterize VelB’s role in governing asexual development and conidiogenesis in A. nidulans. In asexual spore formation, velB deletion strains show reduced number of conidia, and decreased and delayed mRNA accumulation of the key asexual regulatory genes brlA, abaA, and vosA...

  1. Engineering Aspergillus nidulans for heterologous ent-kaurene and gamma-terpinene production.

    Science.gov (United States)

    Bromann, Kirsi; Toivari, Mervi; Viljanen, Kaarina; Ruohonen, Laura; Nakari-Setälä, Tiina

    2016-07-01

    Terpenes are a large and varied group of natural products with a wide array of bioactivities and applications. The chemical production of industrially relevant terpenes can be expensive and time-consuming due to the structural complexity of these compounds. Here, we studied Aspergillus nidulans as a heterologous host for monoterpene and diterpene production. Previously, we identified a novel diterpene gene cluster in A. nidulans and showed that overexpression of the cluster-specific transcription factor (pbcR) led to ent-pimara-8(14),15-diene (PD) production. We report further characterization of the A. nidulans PD synthase gene (pbcA). In A. nidulans, overexpression of pbcA resulted in PD production, while deletion of pbcA abolished PD production. Overexpression of Fusarium fujikuroi ent-kaurene synthase (cps/ks) and Citrus unshiu gamma-terpinene synthase resulted in ent-kaurene and gamma-terpinene production, respectively. A. nidulans is a fungal model organism and a close relative to other industrially relevant Aspergillus species. A. nidulans is a known producer of many secondary metabolites, but its ability to produce heterologous monoterpene and diterpene compounds has not been characterized. Here, we show that A. nidulans is capable of heterologous terpene production and thus has potential as a production host for industrially relevant compounds. The genetic engineering principles reported here could also be applied to other Aspergilli. PMID:27098256

  2. Characterization and biotechnological application of recombinant xylanases from Aspergillus nidulans.

    Science.gov (United States)

    Maitan-Alfenas, Gabriela P; Oliveira, Mariana B; Nagem, Ronaldo A P; de Vries, Ronald P; Guimarães, Valéria M

    2016-10-01

    Two xylanases from Aspergillus nidulans, XlnB and XlnC, were expressed in Pichia pastoris, purified and characterized. XlnB and XlnC achieved maximal activities at 60°C and pH 7.5 and at 50°C and pH 6.0, respectively. XlnB showed to be very thermostable by maintaining 50% of its original activity after 49h incubated at 50°C. XlnB had its highest activity against wheat arabinoxylan while XlnC had the best activity against beechwood xylan. Both enzymes were completely inhibited by SDS and HgCl2. Xylotriose at 1mg/ml also totally inibited XlnB activity. TLC analysis showed that the main product of beechwood xylan hydrolysis by XlnB and XlnC was xylotetraose. An additive effect was shown between XlnB and XlnC and the xylanases of two tested commercial cocktails. Sugarcane bagasse saccharification results showed that these two commercial enzymatic cocktails were able to release more glucose and xylose after supplementation with XlnB and XlnC. PMID:27235731

  3. [Effect of microparticles on echinocandin B production by Aspergillus nidulans].

    Science.gov (United States)

    Niu, Kun; Hu, Yibo; Mao, Jian; Zou, Shuping; Zheng, Yuguo

    2015-07-01

    Anidulafungin is an effective antifungal medicine, which can inhibit activities of candida in vitro and in vivo. Echinocandin B (ECB) is the key precursor of Anidulafungin, thus the price and market prospect of Anidulafungin is directly due to the fermentation titer of ECB. In this study, Aspergillus nidulans was used for ECB fermentation, and the influence of adding microparticles on ECB fermentation was studied, such as talcum powder, Al2O3, and glass beads. The particle size and concentration were the key factors for mycelium morphology and ECB production, and ECB production could reach 1 262.9 mg/L and 1 344.1 mg/L by adding talcum powder of 20 g/L (d50 = 14.2 μm) and 7 glass beads (6 mm), an increase by 33.2% and 41.7%, respectively. The results indicated that the mycelium morphology of filamentous microorganisms and the product yield of fermentation could be improved by adding microparticles remarkably, and it provide an important method for the fermentative optimization of filamentous microorganisms. PMID:26647583

  4. Requirement of Monooxygenase-Mediated Steps for Sterigmatocystin Biosynthesis by Aspergillus nidulans

    OpenAIRE

    Keller, Nancy P.; Watanabe, Coran M. H.; Kelkar, Hemant S.; Adams, Thomas H; Townsend, Craig A.

    2000-01-01

    Sterigmatocystin (ST) and aflatoxin B1 (AFB1) are two polyketide-derived Aspergillus mycotoxins synthesized by functionally identical sets of enzymes. ST, the compound produced by Aspergillus nidulans, is a late intermediate in the AFB1 pathway of A. parasiticus and A. flavus. Previous biochemical studies predicted that five oxygenase steps are required for the formation of ST. A 60-kb ST gene cluster in A. nidulans contains five genes, stcB, stcF, stcL, stcS, and stcW, encoding putative mono...

  5. Biosynthetic Pathway of the Reduced Polyketide Product Citreoviridin in Aspergillus terreus var. aureus Revealed by Heterologous Expression in Aspergillus nidulans.

    Science.gov (United States)

    Lin, Tzu-Shyang; Chiang, Yi-Ming; Wang, Clay C C

    2016-03-18

    Citreoviridin (1) belongs to a class of F1-ATPase β-subunit inhibitors that are synthesized by highly reducing polyketide synthases. These potent mycotoxins share an α-pyrone polyene structure, and they include aurovertin, verrucosidin, and asteltoxin. The identification of the citreoviridin biosynthetic gene cluster in Aspergillus terreus var. aureus and its reconstitution using heterologous expression in Aspergillus nidulans are reported. Two intermediates were isolated that allowed the proposal of the biosynthetic pathway of citreoviridin. PMID:26954888

  6. Selection arena in Aspergillus nidulans : early progeny choice in a filamentous fungus = Selectie arena in Aspergillus nidulans : vroege selectie van nakomelingen in een filamenteuse schimmel

    OpenAIRE

    Bruggeman, J.

    2003-01-01

    Keywords:selection arena, progeny choice, Aspergillus nidulans , fungus, spores, ascospore, conidiospore, asexual, sexual, fruiting body, cleistothecium, zygote, dikaryon, self-sterility, self-fertility, mutation accumulation, fitness, modular organism, auxotrophic.Chapter 1: IntroductionThe selection arena hypothesis states that overproduction of zygotes -a widespread phenomenon in animals and plants- could be explained as part of a quality control mechanism: An enlarged array of zygotes is ...

  7. Developmental characterization and chromosomal mapping of the 5-azacytidine-sensitive fluF locus of Aspergillus nidulans.

    OpenAIRE

    Tamame, M; Antequera, F; Santos, E.

    1988-01-01

    In Aspergillus nidulans, a fungus that possesses negligible, if any, levels of methylation in its genome, low concentrations of 5-azacytidine (5-AC) convert a high percentage of the cell population to fluffy phenotypic variants through a heritable modification of a single nuclear gene (M. Tamame, F. Antequera, J. R. Villanueva, and T. Santos, Mol. Cell. Biol. 3:2287-2297, 1983). This new 5-AC-altered locus, designated here fluF1, was mapped as the closest marker to the centromere that has bee...

  8. DNA-mediated transformation of the filamentous fungus Aspergillus nidulans.

    OpenAIRE

    Wernars, K.

    1986-01-01

    Although transformation of S.   cerevisiae and N.crassa already could be achieved at the end of the seventies, positive results for A.nidulans had to await the isolation of useful selection markers. As soon as cloned fungal genes of homologous ( amd S, trp C and arg B from A.nidulans ) and heterologous ( pyr 4 from N.crassa ) origin became available transformation procedures for A.nidulans were developed (Ballance et al. 1983; Tilburn et al. 1983; Yelton et al. 1984; John and Pederby 1984). T...

  9. Antisense silencing of the creA gene in Aspergillus nidulans

    DEFF Research Database (Denmark)

    Bautista, L. F.; Aleksenko, Alexei Y.; Hentzer, Morten; Henriksen, Anne Laurence Santerre; Nielsen, Jens

    2000-01-01

    Antisense expression of a portion of the gene encoding the major carbon catabolite repressor CREA in Aspergillus nidulans resulted in a substantial increase in the levels of glucose-repressible enzymes, both endogenous and heterologous, in the presence of glucose. The derepression effect was...

  10. Male and female roles in crosses of Aspergillus nidulans as revealed by vegetatively incompatible parents

    NARCIS (Netherlands)

    Bruggeman, I.M.; Debets, A.J.M.; Swart, K.; Hoekstra, R.F.

    2003-01-01

    To resolve the role of male and female nuclei and mitochondria in cleistothecium formation in the model organism Aspergillus nidulans, we analysed the genetic constituents of cleistothecia, from crosses between vegetatively compatible and incompatible parents. We used markers that enabled us to dete

  11. Characterization of the AN6448 cluster in Aspergillus nidulans

    DEFF Research Database (Denmark)

    Nielsen, Jakob Blæsbjerg; Klejnstrup, Marie Louise; Khorsand-Jamal, Paiman; Holm, Dorte Koefoed; Nielsen, Michael Lynge; Kabat, Anna Monika; Rank, Christian; Gotfredsen, Charlotte Held; Larsen, T. O.; Mortensen, Uffe Hasbro

    2012-01-01

    With the aim of mapping the polyketome of A. nidulans we have made a library of strains, which individually overexpress PKS genes from an ectopic locus. A screen of this collection on different media demonstrated that AN6448 leads to production of 3-MOA. An inspection of the DNA sequence surround...

  12. Novel telomere-anchored PCR approach for studying sexual stage telomeres in Aspergillus nidulans.

    Science.gov (United States)

    Wang, Nengding; Rizvydeen, Saajidha; Vahedi, Mithaq; Vargas Gonzalez, Daysi M; Allred, Amanda L; Perry, Dustin W; Mirabito, Peter M; Kirk, Karen E

    2014-01-01

    Telomere length varies between germline and somatic cells of the same organism, leading to the hypothesis that telomeres are lengthened during meiosis. However, little is known about the meiotic telomere length in many organisms. In the filamentous fungus Aspergillus nidulans, the telomere lengths in hyphae and asexual spores are invariant. No study using existing techniques has determined the telomere length of the sexual ascospores due to the relatively low abundance of pure meiotic cells in A. nidulans and the small quantity of DNA present. To address this, we developed a simple and sensitive PCR strategy to measure the telomere length of A. nidulans meiotic cells. This novel technique, termed "telomere-anchored PCR," measures the length of the telomere on chromosome II-L using a small fraction of the DNA required for the traditional terminal restriction fragment (TRF) Southern analysis. Using this approach, we determined that the A. nidulans ascospore telomere length is virtually identical to telomeres of other cell types from this organism, approximately 110 bp, indicating that a surprisingly strict telomere length regulation exists in the major cell types of A. nidulans. When the hyphal telomeres were measured in a telomerase reverse transcriptase (TERT) knockout strain, small decreases in length were readily detected. Thus, this technique can detect telomeres in relatively rare cell types and is particularly sensitive in measuring exceptionally short telomeres. This rapid and inexpensive telomere-anchored PCR method potentially can be utilized in other filamentous fungi and types of organisms. PMID:24927411

  13. Gβ-like CpcB plays a crucial role for growth and development of Aspergillus nidulans and Aspergillus fumigatus.

    Directory of Open Access Journals (Sweden)

    Qing Kong

    Full Text Available Growth, development, virulence and secondary metabolism in fungi are governed by heterotrimeric G proteins (G proteins. A Gβ-like protein called Gib2 has been shown to function as an atypical Gβ in Gpa1-cAMP signaling in Cryptococcus neoformans. We found that the previously reported CpcB (cross pathway control B protein is the ortholog of Gib2 in Aspergillus nidulans and Aspergillus fumigatus. In this report, we further characterize the roles of CpcB in governing growth, development and toxigenesis in the two aspergilli. The deletion of cpcB results in severely impaired cellular growth, delayed spore germination, and defective asexual sporulation (conidiation in both aspergilli. Moreover, CpcB is necessary for proper expression of the key developmental activator brlA during initiation and progression of conidiation in A. nidulans and A. fumigatus. Somewhat in accordance with the previous study, the absence of cpcB results in the formation of fewer, but not micro-, cleistothecia in A. nidulans in the presence of wild type veA, an essential activator of sexual development. However, the cpcB deletion mutant cleistothecia contain no ascospores, validating that CpcB is required for progression and completion of sexual fruiting including ascosporogenesis. Furthermore, unlike the canonical GβSfaD, CpcB is not needed for the biosynthesis of the mycotoxin sterigmatocystin (ST as the cpcB null mutant produced reduced amount of ST with unaltered STC gene expression. However, in A. fumigatus, the deletion of cpcB results in the blockage of gliotoxin (GT production. Further genetic analyses in A. nidulans indicate that CpcB may play a central role in vegetative growth, which might be independent of FadA- and GanB-mediated signaling. A speculative model summarizing the roles of CpcB in conjunction with SfaD in A. nidulans is presented.

  14. Actindynamik und -regulation in dem filamentösen Pilz Aspergillus nidulans

    OpenAIRE

    Bergs, Anna Rebecca

    2015-01-01

    Im Zuge dieser Dissertation wurde die Actindynamik und -regulation in dem filamentösen Pilz Aspergillus nidulans untersucht. Hierbei wurde die Actindynamik mit Hilfe der Marker TpmA und Lifeact ermittelt. Zudem wurde der Zusammenhang zwischen dem Actincytoskelett und anderen Polaritätsfaktoren, wie Mikrotubuli, Zellendmarkern, Septinen und der Calciumkonzentration erforscht. Experimente zur hochauflösenden Mikroskopie von Mikrotubuli brachten zudem Erkenntnisse zur Mikrotubuli-Bündelung.

  15. Aspergillus nidulans protein kinase A plays an important role in cellulase production

    OpenAIRE

    de Assis, Leandro José; Ries, Laure Nicolas Annick; Savoldi, Marcela; dos Reis, Thaila Fernanda; Brown, Neil Andrew; Goldman, Gustavo Henrique

    2015-01-01

    Background The production of bioethanol from lignocellulosic feedstocks is dependent on lignocellulosic biomass degradation by hydrolytic enzymes. The main component of lignocellulose is cellulose and different types of organisms are able to secrete cellulases. The filamentous fungus Aspergillus nidulans serves as a model organism to study cellulase production and the available tools allow exploring more in depth the mechanisms governing cellulase production and carbon catabolite repression. ...

  16. RNA Silencing in Aspergillus nidulans Is Independent of RNA-Dependent RNA Polymerases

    OpenAIRE

    Hammond, T. M.; Keller, N P

    2005-01-01

    The versatility of RNA-dependent RNA polymerases (RDRPs) in eukaryotic gene silencing is perhaps best illustrated in the kingdom Fungi. Biochemical and genetic studies of Schizosaccharomyces pombe and Neurospora crassa show that these types of enzymes are involved in a number of fundamental gene-silencing processes, including heterochromatin regulation and RNA silencing in S. pombe and meiotic silencing and RNA silencing in N. crassa. Here we show that Aspergillus nidulans, another model fung...

  17. Sex slows down the accumulation of deleterious mutations in the homothallic fungus Aspergillus nidulans.

    OpenAIRE

    Bruggeman, Judith; Debets, Alfons J. M.; Wijngaarden, Pieter J.; deVisser, J Arjan G M; Hoekstra, Rolf F.

    2003-01-01

    Coexistence of sexual and asexual reproduction within the same individual is an intriguing problem, especially when it concerns homothallic haplonts, like the fungus Aspergillus nidulans. In this fungus asexual and sexual offspring have largely identical genotypes. This genetic model organism is an ideal tool to measure possible fitness effects of sex (compared to asex) resulting from causes other than recombination. In this article we show that slightly deleterious mutations accumulate at a ...

  18. A Novel Regulator Couples Sporogenesis and Trehalose Biogenesis in Aspergillus nidulans

    OpenAIRE

    Ni, Min; Yu, Jae-Hyuk

    2007-01-01

    Trehalose is a compatible osmolyte produced by bacteria, fungi, insects and plants to protect the integrity of cells against various environmental stresses. Spores, the reproductive, survival and infection bodies of fungi require high amounts of trehalose for long-term survival. Here, via a gain-of-function genetic screen, we identify the novel regulator VosA that couples the formation of spores and focal trehalose biogenesis in the model fungus Aspergillus nidulans. The vosA gene is expresse...

  19. Posttranscriptional Control Mediates Cell Type-Specific Localization of Catalase A during Aspergillus nidulans Development

    OpenAIRE

    Navarro, Rosa E.; Aguirre, Jesús

    1998-01-01

    Two differentially regulated catalase genes have been identified in the fungus Aspergillus nidulans. The catA gene belongs to a class whose transcripts are specifically induced during asexual sporulation (conidiation) and encodes a catalase accumulated in conidia. Using a developmental mutant affected in the brlA gene, which is unable to form conidia but capable of producing sexual spores (ascospores), we demonstrated that the catA mRNA accumulated during induction of conidiation but did not ...

  20. Physiological characterisation of recombinant Aspergillus nidulans strains with different creA genotypes expressing A-oryzae alpha-amylase

    DEFF Research Database (Denmark)

    Agger, Teit; Petersen, J.B.; O'Connor, S.M.;

    2002-01-01

    The physiology of three strains of Aspergillus nidulans was examined-a creA deletion strain, a wild type creA genotype and a strain containing extra copies of the creA gene, all producing Aspergillus oryzae alpha-amylase. The strains were cultured in batch and continuous cultivations and the...

  1. Genotoxicity of the cyclo-oxygenase-inhibitor sulindac sulfide in the filamentous fungus Aspergillus nidulans Genotoxicidade de sulfeto de sulindaco em Aspergillus nidulans

    Directory of Open Access Journals (Sweden)

    Claudinéia Conationi da Silva Franco

    2007-09-01

    Full Text Available Sulindac sulfide is a non-steroidal anti-inflammatory drug (NSAID with chemopreventive effect on human cancer cells. Due to the involvement of the somatic recombination in the carcinogenic process, sulindac sulfide's recombinogenic potential was evaluated by the Homozygotization Index (HI in the filamentous fungus Aspergillus nidulans. The drug's recombinogenic potential was evaluated by its capacity to induce homozygosis of recessive genes from heterozygous diploid cells. Sulindac sulfide at 175 and 350 µM concentrations induced mitotic recombination in A. nidulans diploid cells, with HI values for genetic markers higher than 2.0, and significantly different from control HI values. The recombinogenic effect of NSAID was related to the induction of DNA strand breaks and cell cycle alterations. Sulindac sulfide's carcinogenic potential was also discussed.Sulfeto de sulindaco é um antiinflamatório não-esteroidal com efeitos quimiopreventivos em cânceres humanos. O presente estudo teve como objetivo avaliar o potencial recombinagênico do sulfeto de sulindaco em células diplóides de Aspergillus nidulans. O efeito recombinagênico da droga foi demonstrado através da homozigotização de genes recessivos, previamente presentes em heterozigose. Os valores de HI (Índice de Homozigotização para diferentes marcadores genéticos apresentaram-se maiores do que 2,0 e significativamente diferentes dos valores obtidos em sulfeto de sulindaco ausência da droga (controle. O potencial recombinagênico do sulfeto de sulindaco foi associado à indução de quebras na molécula do DNA e a alterações no ciclo celular. O potencial carcinogênico do sulfeto de sulindaco foi discutido no presente trabalho.

  2. alpha-Amylase production in high cell density submerged cultivation of Aspergillus oryzae and A. nidulans.

    Science.gov (United States)

    Agger, T; Spohr, A B; Nielsen, J

    2001-01-01

    The effect of biomass concentration on the formation of Aspergillus oryzae alpha-amylase during submerged cultivation with A. oryzae and recombinant A. nidulans strains has been investigated. It was found that the specific rate of alpha-amylase formation in chemostats decreased significantly with increasing biomass concentration in the range of approx. 2-12 g dry weight kg(-1). When using a recombinant A. nidulans strain in which the gene responsible for carbon catabolite repression of the A. oryzae alpha-amylase gene (creA) was deleted, no significant decrease in the specific rate of alpha-amylase formation was observed. On the basis of the experimental results, it is suggested that the low value of the specific alpha-amylase productivity observed at high biomass concentration is caused by slow mixing of the concentrated feed solution in the viscous fermentation medium. PMID:11234963

  3. Preliminary X-ray crystallographic studies of UDP-glucose-4-epimerase from Aspergillus nidulans

    International Nuclear Information System (INIS)

    UDP-glucose-4-epimerase from A. nidulans has been crystallized as a complex with the substrate UDP-galactose using the microbatch method under paraffin oil. UDP-glucose-4-epimerase (GALE) from Aspergillus nidulans was overexpressed in Escherichia coli, purified via His-tag affinity chromatography and cocrystallized with UDP-galactose using the microbatch method. The crystals diffracted to 2.4 Å resolution using synchrotron radiation on the Canadian Light Source 08ID-1 beamline. Examination of the data with d*TREK revealed nonmerohedral twinning, from which a single lattice was ultimately extracted for processing. The final space group was found to be C2, with unit-cell parameters a = 66.13, b = 119.15, c = 161.42 Å, β = 98.48°. An initial structure solution has been obtained via molecular replacement employing human GALE as a template model

  4. A combined genetic and multi medium approach revels new secondary metabolites in Aspergillus nidulans

    DEFF Research Database (Denmark)

    Klejnstrup, Marie Louise; Nielsen, Morten Thrane; Frisvad, Jens Christian; Mortensen, Uffe Hasbro; Larsen, Thomas Ostenfeld

    Secondary metabolites are a diverse group of metabolites which serve as important natural sources of drugs for treating diseases. The availability of full genome sequences of several filamentous fungi has revealed a large genetic potential for production of secondary metabolites that are not...... observed under standard laboratory conditions. Genetic approaches have proven a fruitfull strategy towards the production and identification of these unknown metabolites. Examples include deletion of the cclA1 and laeA2 genes in A. nidulans which affects the expression of secondary metabolites including...... monodictyphenone and terrequinone A respectively. We have deleted the cclA gene in A. nidulans and grown the mutants on several complex media to provoke the production of secondary metabolites. This resulted in the production of several metabolites not previously reported from A. nidulans. Some of these have been...

  5. Application of a new dual localization-affinity purification tag reveals novel aspects of protein kinase biology in Aspergillus nidulans.

    Directory of Open Access Journals (Sweden)

    Colin P De Souza

    Full Text Available Filamentous fungi occupy critical environmental niches and have numerous beneficial industrial applications but devastating effects as pathogens and agents of food spoilage. As regulators of essentially all biological processes protein kinases have been intensively studied but how they regulate the often unique biology of filamentous fungi is not completely understood. Significant understanding of filamentous fungal biology has come from the study of the model organism Aspergillus nidulans using a combination of molecular genetics, biochemistry, cell biology and genomic approaches. Here we describe dual localization-affinity purification (DLAP tags enabling endogenous N or C-terminal protein tagging for localization and biochemical studies in A. nidulans. To establish DLAP tag utility we endogenously tagged 17 protein kinases for analysis by live cell imaging and affinity purification. Proteomic analysis of purifications by mass spectrometry confirmed association of the CotA and NimXCdk1 kinases with known binding partners and verified a predicted interaction of the SldABub1/R1 spindle assembly checkpoint kinase with SldBBub3. We demonstrate that the single TOR kinase of A. nidulans locates to vacuoles and vesicles, suggesting that the function of endomembranes as major TOR cellular hubs is conserved in filamentous fungi. Comparative analysis revealed 7 kinases with mitotic specific locations including An-Cdc7 which unexpectedly located to mitotic spindle pole bodies (SPBs, the first such localization described for this family of DNA replication kinases. We show that the SepH septation kinase locates to SPBs specifically in the basal region of apical cells in a biphasic manner during mitosis and again during septation. This results in gradients of SepH between G1 SPBs which shift along hyphae as each septum forms. We propose that SepH regulates the septation initiation network (SIN specifically at SPBs in the basal region of G1 cells and that

  6. Developmental characterization and chromosomal mapping of the 5-azacytidine-sensitive fluF locus of Aspergillus nidulans.

    Science.gov (United States)

    Tamame, M; Antequera, F; Santos, E

    1988-01-01

    In Aspergillus nidulans, a fungus that possesses negligible, if any, levels of methylation in its genome, low concentrations of 5-azacytidine (5-AC) convert a high percentage of the cell population to fluffy phenotypic variants through a heritable modification of a single nuclear gene (M. Tamame, F. Antequera, J. R. Villanueva, and T. Santos, Mol. Cell. Biol. 3:2287-2297, 1983). This new 5-AC-altered locus, designated here fluF1, was mapped as the closest marker to the centromere that has been identified so far on the right arm of chromosome VIII. Of all mutagens tested, only 5-AC induced the fluffy phenotype with a significant frequency. Furthermore, we determined that the wild-type, dominant allele of the fluF gene was primarily accessible to modification by 5-AC at the initial stages of fungal vegetative growth. These results indicated that 5-AC does not act through random mutagenic action but, rather, that fluF constitutes a specific target for this drug during a well-defined period of fungal development. Alteration of fluF by 5-AC resulted in a dramatic modification of the developmental program of A. nidulans. The resulting fluffy clones were characterized by massive, uncontrolled proliferation of undifferentiated hyphae, a drastic delay in the onset of asexual differentiation (conidiation), and colonies with an invasive nature. These features are reminiscent of the malignant properties of tumor cells. We propose that the locus fluF plays a primary role in the control of cell proliferation in A. nidulans and that its alteration by 5-AC produces pleiotropic modifications of the developmental program of this fungus. Images PMID:2463470

  7. Velvet-mediated repression of β-glucan synthesis in Aspergillus nidulans spores.

    Science.gov (United States)

    Park, Hee-Soo; Yu, Yeong Man; Lee, Mi-Kyung; Maeng, Pil Jae; Kim, Sun Chang; Yu, Jae-Hyuk

    2015-01-01

    Beta-glucans are a heterologous group of fibrous glucose polymers that are a major constituent of cell walls in Ascomycetes and Basidiomycetes fungi. Synthesis of β (1,3)- and (1,6)-glucans is coordinated with fungal cell growth and development, thus, is under tight genetic regulation. Here, we report that β-glucan synthesis in both asexual and sexual spores is turned off by the NF-kB like fungal regulators VosA and VelB in Aspergillus nidulans. Our genetic and genomic analyses have revealed that both VosA and VelB are necessary for proper down-regulation of cell wall biosynthetic genes including those associated with β-glucan synthesis in both types of spores. The deletion of vosA or velB results in elevated accumulation of β-glucan in asexual spores. Double mutant analyses indicate that VosA and VelB play an inter-dependent role in repressing β-glucan synthesis in asexual spores. In vivo chromatin immuno-precipitation analysis shows that both VelB and VosA bind to the promoter region of the β-glucan synthase gene fksA in asexual spores. Similarly, VosA is required for proper repression of β-glucan synthesis in sexual spores. In summary, the VosA-VelB hetero-complex is a key regulatory unit tightly controlling proper levels of β-glucan synthesis in asexual and sexual spores. PMID:25960370

  8. Laser capture microdissection to identify septum-associated proteins in Aspergillus nidulans.

    Science.gov (United States)

    Zhang, Ying; Fischer, Reinhard; Teichert, Ines; Kück, Ulrich

    2016-05-01

    To spatially resolve genetic differences at the cellular level, the laser-capture microdissection technique was developed. With this method cells can be cut from tissues with a laser beam and analyzed for DNA, RNA or protein composition. Here we adapted the technique to isolate septal microtubule-organizing center (MTOC)-associated proteins in Aspergillus nidulans About 3000 septa were collected and subjected to peptide fingerprinting by mass-spectrometric analysis. We identified the microtubule polymerase AlpA and found it interacts with ApsB specifically at sMTOCs, suggesting that AlpA might be involved in the assembly or the functioning of this protein complex. PMID:26951366

  9. Sequence and functional analysis of the positively acting regulatory gene amdR from Aspergillus nidulans.

    OpenAIRE

    Andrianopoulos, A; Hynes, M J

    1990-01-01

    The positively acting regulatory gene amdR of Aspergillus nidulans coordinately regulates the expression of five structural genes involved in the catabolism of certain amides (amdS), omega amino acids (gatA and gabA), and lactams (lamA and lamB) in the presence of omega amino acid inducers. Analysis of the amdR gene showed that it contains three small introns, heterogeneous 5' and 3' transcription sites, and multiple AUG codons prior to the major AUG initiator. The predicted amdR protein sequ...

  10. Aspergillus nidulans wetA activates spore-specific gene expression.

    OpenAIRE

    Marshall, M. A.; Timberlake, W E

    1991-01-01

    The Aspergillus nidulans wetA gene is required for synthesis of cell wall layers that make asexual spores (conidia) impermeable. In wetA mutant strains, conidia take up water and autolyze rather than undergoing the final stages of maturation. wetA is activated during conidiogenesis by sequential expression of the brlA and abaA regulatory genes. To determine whether wetA regulates expression of other sporulation-specific genes, its coding region was fused to a nutritionally regulated promoter ...

  11. Identification and characterization of genes required for hyphal morphogenesis in the filamentous fungus Aspergillus nidulans.

    OpenAIRE

    Harris, S D; Hofmann, A F; Tedford, H W; Lee, M.P.

    1999-01-01

    In the filamentous fungus Aspergillus nidulans, germination of an asexual conidiospore results in the formation of a hyphal cell. A key feature of spore germination is the switch from isotropic spore expansion to polarized apical growth. Here, temperature-sensitive mutations are used to characterize the roles of five genes (sepA, hypA, podB-podD) in the establishment and maintenance of hyphal polarity. Evidence that suggests that the hypA, podB, and sepA genes are required for multiple aspect...

  12. Screening of Aspergillus nidulans metabolites from habitat mimicking media using LC-DAD-TOFMS system

    DEFF Research Database (Denmark)

    Klitgaard, Andreas; Holm, Dorte Koefoed; Frisvad, Jens Christian; Nielsen, Kristian Fog

    Fungi are a valuable source of metabolites and other bioactive compounds. These compounds are essential for human society, and it is estimated that around 49% of the drugs used to treat cancer are natural products or derived therefrom. Six different wild types of Aspergillus nidulans have been...... cultured on a range of different habitat mimicking media. Extracts from the fungi were analyzed using a LC-DAD-TOFMS system, and by screening the extracts using an in-house database of known fungal metabolites. Using this database we were able to easily select unknown compounds, and dereplicate these using...

  13. A time course analysis of the extracellular proteome of Aspergillus nidulans growing on sorghum stover

    Directory of Open Access Journals (Sweden)

    Saykhedkar Sayali

    2012-07-01

    Full Text Available Abstract Background Fungi are important players in the turnover of plant biomass because they produce a broad range of degradative enzymes. Aspergillus nidulans, a well-studied saprophyte and close homologue to industrially important species such as A. niger and A. oryzae, was selected for this study. Results A. nidulans was grown on sorghum stover under solid-state culture conditions for 1, 2, 3, 5, 7 and 14 days. Based on analysis of chitin content, A. nidulans grew to be 4-5% of the total biomass in the culture after 2 days and then maintained a steady state of 4% of the total biomass for the next 12 days. A hyphal mat developed on the surface of the sorghum by day one and as seen by scanning electron microscopy the hyphae enmeshed the sorghum particles by day 5. After 14 days hyphae had penetrated the entire sorghum slurry. Analysis (1-D PAGE LC-MS/MS of the secretome of A. nidulans, and analysis of the breakdown products from the sorghum stover showed a wide range of enzymes secreted. A total of 294 extracellular proteins were identified with hemicellulases, cellulases, polygalacturonases, chitinases, esterases and lipases predominating the secretome. Time course analysis revealed a total of 196, 166, 172 and 182 proteins on day 1, 3, 7 and 14 respectively. The fungus used 20% of the xylan and cellulose by day 7 and 30% by day 14. Cellobiose dehydrogenase, feruloyl esterases, and CAZy family 61 endoglucanases, all of which are thought to reduce the recalcitrance of biomass to hydrolysis, were found in high abundance. Conclusions Our results show that A. nidulans secretes a wide array of enzymes to degrade the major polysaccharides and lipids (but probably not lignin by 1 day of growth on sorghum. The data suggests simultaneous breakdown of hemicellulose, cellulose and pectin. Despite secretion of most of the enzymes on day 1, changes in the relative abundances of enzymes over the time course indicates that the set of enzymes

  14. Screening of medicinal plants for induction of somatic segregation activity in Aspergillus nidulans.

    Science.gov (United States)

    Ramos Ruiz, A; De la Torre, R A; Alonso, N; Villaescusa, A; Betancourt, J; Vizoso, A

    1996-07-01

    Knowledge about mutagenic properties of plants commonly used in traditional medicine is limited. A screening for genotoxic activity was carried out in aqueous or alcoholic extracts prepared from 13 medicinal plants widely used as folk medicine in Cuba: Lepidium virginicum L. (Brassicaceae): Plantago major L. and Plantago lanceolata L. (Plantaginaceae); Ortosiphon aristatus Blume, Mentha x piperita L., Melissa officinalis L. and Plectranthus amboinicus (Lour.) Spreng. (Lamiaceae); Cymbopogon citratus (DC.) Stapf (Poaceae); Passiflora incarnata L. (Passifloraceae); Zingiber officinale Roscoe (Zingiberaceae); Piper auritum HBK. (Piperaceae); Schinus terebinthifolius Raddi (Anacardeaceae) and Momordica charantia L. (Cucurbitaceae). A plate incorporation assay with Aspergillus nidulans was employed, allowing detection of somatic segregation as a result of mitotic crossing-over, chromosome malsegregation or clastogenic effects. Aspergillus nidulans D-30, a well-marked strain carrying four recessive mutations for conidial color in heterozygosity, which permitted the direct visual detection of segregants, was used throughout this study. As a result, only in the aqueous extract of one of the plants screened (Momordica charantia) a statistical significant increase in the frequency of segregant sectors per colony was observed, and consequently, a genotoxic effect is postulated. PMID:8771452

  15. Suppression and Enhancement of the Aspergillus Nidulans Medusa Mutation by Altered Dosage of the Bristle and Stunted Genes

    OpenAIRE

    Busby, T. M.; Miller, K. Y.; Miller, B.L.

    1996-01-01

    Asexual reproduction in Aspergillus nidulans is characterized by the orderly differentiation of multicellular reproductive structures (conidiophores) and chains of uninucleate conidia (spores). Mutations in the developmental modifier medusa (medA) result in aberrant conidiophores with branching chains of reiterated reproductive cells (metulae), delayed conidial differentiation and frequent reinitiation of secondary conidiophores. We show that incorrect morphology is in part a consequence of m...

  16. KdmB, a Jumonji Histone H3 Demethylase, Regulates Genome-Wide H3K4 Trimethylation and Is Required for Normal Induction of Secondary Metabolism in Aspergillus nidulans.

    Science.gov (United States)

    Gacek-Matthews, Agnieszka; Berger, Harald; Sasaki, Takahiko; Wittstein, Kathrin; Gruber, Clemens; Lewis, Zachary A; Strauss, Joseph

    2016-08-01

    Histone posttranslational modifications (HPTMs) are involved in chromatin-based regulation of fungal secondary metabolite biosynthesis (SMB) in which the corresponding genes-usually physically linked in co-regulated clusters-are silenced under optimal physiological conditions (nutrient-rich) but are activated when nutrients are limiting. The exact molecular mechanisms by which HPTMs influence silencing and activation, however, are still to be better understood. Here we show by a combined approach of quantitative mass spectrometry (LC-MS/MS), genome-wide chromatin immunoprecipitation (ChIP-seq) and transcriptional network analysis (RNA-seq) that the core regions of silent A. nidulans SM clusters generally carry low levels of all tested chromatin modifications and that heterochromatic marks flank most of these SM clusters. During secondary metabolism, histone marks typically associated with transcriptional activity such as H3 trimethylated at lysine-4 (H3K4me3) are established in some, but not all gene clusters even upon full activation. KdmB, a Jarid1-family histone H3 lysine demethylase predicted to comprise a BRIGHT domain, a zinc-finger and two PHD domains in addition to the catalytic Jumonji domain, targets and demethylates H3K4me3 in vivo and mediates transcriptional downregulation. Deletion of kdmB leads to increased transcription of about ~1750 genes across nutrient-rich (primary metabolism) and nutrient-limiting (secondary metabolism) conditions. Unexpectedly, an equally high number of genes exhibited reduced expression in the kdmB deletion strain and notably, this group was significantly enriched for genes with known or predicted functions in secondary metabolite biosynthesis. Taken together, this study extends our general knowledge about multi-domain KDM5 histone demethylases and provides new details on the chromatin-level regulation of fungal secondary metabolite production. PMID:27548260

  17. Aspergillus nidulans cell wall composition and function change in response to hosting several Aspergillus fumigatus UDP-galactopyranose mutase activity mutants.

    Directory of Open Access Journals (Sweden)

    Md Kausar Alam

    Full Text Available Deletion or repression of Aspergillus nidulans ugmA (AnugmA, involved in galactofuranose biosynthesis, impairs growth and increases sensitivity to Caspofungin, a β-1,3-glucan synthesis antagonist. The A. fumigatus UgmA (AfUgmA crystal structure has been determined. From that study, AfUgmA mutants with altered enzyme activity were transformed into AnugmA▵ to assess their effect on growth and wall composition in A. nidulans. The complemented (AnugmA::wild type AfugmA strain had wild type phenotype, indicating these genes had functional homology. Consistent with in vitro studies, AfUgmA residues R182 and R327 were important for its function in vivo, with even conservative amino (RK substitutions producing AnugmA? phenotype strains. Similarly, the conserved AfUgmA loop III histidine (H63 was important for Galf generation: the H63N strain had a partially rescued phenotype compared to AnugmA▵. Collectively, A. nidulans strains that hosted mutated AfUgmA constructs with low enzyme activity showed increased hyphal surface adhesion as assessed by binding fluorescent latex beads. Consistent with previous qPCR results, immunofluorescence and ELISA indicated that AnugmA▵ and AfugmA-mutated A. nidulans strains had increased α-glucan and decreased β-glucan in their cell walls compared to wild type and AfugmA-complemented strains. Like the AnugmA▵ strain, A. nidulans strains containing mutated AfugmA showed increased sensitivity to antifungal drugs, particularly Caspofungin. Reduced β-glucan content was correlated with increased Caspofungin sensitivity. Aspergillus nidulans wall Galf, α-glucan, and β-glucan content was correlated in A. nidulans hyphal walls, suggesting dynamic coordination between cell wall synthesis and cell wall integrity.

  18. Functional and Physical Interaction of Blue- and Red-Light Sensors in Aspergillus nidulans

    International Nuclear Information System (INIS)

    Light sensing is very important for organisms in all biological kingdoms to adapt to changing environmental conditions. It was discovered recently that plant-like phytochrome is in- volved in light sensing in the filamentous fungus Aspergillus nidulans [1]. Here, we show that phytochrome (FphA) is part of a protein complex containing LreA (WC-1) and LreB (WC-[2, 3], two central components of the Neurospora crassa blue-light-sensing system. We found that FphA represses sexual development and mycotoxin formation, whereas LreA and LreB stimulate both. Surprisingly, FphA interacted with LreB and with VeA, another regulator involved in light sensing and mycotoxin biosynthesis. LreB also interacted with LreA. All protein interactions occurred in the nucleus, despite cytoplasmic subfractions of the proteins. Whereas the FphA-VeA interaction was dependent on the presence of the linear tetrapyrrole in FphA, the interaction between FphA and LreB was chromophore independent. These results suggest that morphological and physiological differen- tiations in A. nidulans are mediated through a network consisting of FphA, LreA, LreB, and VeA acting in a large protein complex in the nucleus, sensing red and blue light. (author)

  19. EVALUATION OF CELL CYCLE OF Aspergillus nidulans EXPOSED TO THE EXTRACT OF Copaifera officinalis L PLANT

    Directory of Open Access Journals (Sweden)

    Simone Jurema Ruggeri Chiuchetta, Uériton Dias de Oliveira e Josy Fraccaro de Marins

    2006-12-01

    Full Text Available The oil extracted from the Copaifera officinalis L plant has been used in popular medicine to the treatment of several diseases, like cancer. In eukaryotic cells, the process of cellular proliferation follows a standard cycle, named cellular cycle. The transformation of a normal cell in a malignant one requires several steps, in which genes that control normal cellular division or cellular death are modified. Aspergillus nidulans fungus is an excellent system for the study of the cellular differentiation. Its asexual cycle results in the formation of conidia, which are disposed like chains, constituting a structure named conidiophore. This structure consists in an aerial hifae, multinucleate vesicle and uninucleate cells. Current research evaluated the capacity of the C. officinalis L plant extract in promoting alterations in the cellular cycle of A. nidulans diploid strains, by observing macroscopic and microscopic alterations in cellular growth of this fungus. Results shown that no macroscopic alterations were observed in cellular growth of strains exposed to the extract, however, microscopic alterations of conidiophore have been observed in the different extract concentrations analyzed. In this way, the study of the action of C. officinalis L plant extract becomes important considering the fact that this substance is capable to promote alterations in cellular cycle of eukaryotic cells.

  20. Thiamine synthesis regulates the fermentation mechanisms in the fungus Aspergillus nidulans.

    Science.gov (United States)

    Shimizu, Motoyuki; Masuo, Shunsuke; Itoh, Eriko; Zhou, Shengmin; Kato, Masashi; Takaya, Naoki

    2016-09-01

    Thiamine pyrophosphate (TPP) is a critical cofactor and its biosynthesis is under the control of TPP availability. Here we disrupted a predicted thiA gene of the fungus Aspergillus nidulans and demonstrated that it is essential for synthesizing cellular thiamine. The thiamine riboswitch is a post-transcriptional mechanism for TPP to repress gene expression and it is located on A. nidulans thiA pre-messenger RNA. The thiA riboswitch was not fully derepressed under thiamine-limited conditions, and fully derepressed under environmental stressors. Upon exposure to hypoxic stress, the fungus accumulated more ThiA and NmtA proteins, and more thiamine than under aerobic conditions. The thiA gene was required for the fungus to upregulate hypoxic branched-chain amino acids and ethanol fermentation that involve enzymes containing TPP. These findings indicate that hypoxia modulates thiA expression through the thiamine riboswitch, and alters cellular fermentation mechanisms by regulating the activity of the TPP enzymes. PMID:26967817

  1. Roles of Aspergillus nidulans Cdc42/Rho GTPase regulators in hyphal morphogenesis and development.

    Science.gov (United States)

    Si, Haoyu; Rittenour, William R; Harris, Steven D

    2016-01-01

    The Rho-related family of GTPases are pivotal regulators of morphogenetic processes in diverse eukaryotic organisms. In the filamentous fungi two related members of this family, Cdc42 and Rac1, perform particularly important roles in the establishment and maintenance of hyphal polarity. The activity of these GTPases is tightly controlled by two sets of regulators: guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs). Despite the importance of Cdc42 and Rac1 in polarized hyphal growth, the morphogenetic functions of their cognate GEFs and GAPs have not been widely characterized in filamentous fungi outside the Saccharomycotina. Here we present a functional analysis of the Aspergillus nidulans homologs of the yeast GEF Cdc24 and the yeast GAP Rga1. We show that Cdc24 is required for the establishment of hyphal polarity and localizes to hyphal tips. We also show that Rga1 is necessary for the suppression of branching in developing conidiophores. During asexual development Rga1 appears to act primarily via Cdc42 and in doing so serves as a critical determinant of conidiophore architecture. Our results provide new insight into the roles of Cdc42 during development in A nidulans. PMID:26932184

  2. New Aspercryptins, Lipopeptide Natural Products, Revealed by HDAC Inhibition in Aspergillus nidulans.

    Science.gov (United States)

    Henke, Matthew T; Soukup, Alexandra A; Goering, Anthony W; McClure, Ryan A; Thomson, Regan J; Keller, Nancy P; Kelleher, Neil L

    2016-08-19

    Unlocking the biochemical stores of fungi is key for developing future pharmaceuticals. Through reduced expression of a critical histone deacetylase in Aspergillus nidulans, increases of up to 100-fold were observed in the levels of 15 new aspercryptins, recently described lipopeptides with two noncanonical amino acids derived from octanoic and dodecanoic acids. In addition to two NMR-verified structures, MS/MS networking helped uncover an additional 13 aspercryptins. The aspercryptins break the conventional structural orientation of lipopeptides and appear "backward" when compared to known compounds of this class. We have also confirmed the 14-gene aspercryptin biosynthetic gene cluster, which encodes two fatty acid synthases and several enzymes to convert saturated octanoic and dodecanoic acid to α-amino acids. PMID:27310134

  3. Studies of the Production of Fungal Polyketides in Aspergillus nidulans by Using Systems Biology Tools

    DEFF Research Database (Denmark)

    Panagiotou, Gianni; Andersen, Mikael Rørdam; Grotkjær, Thomas;

    2009-01-01

    that overexpression of xpkA does not directly improve 6-MSA production on glucose, but it is possible, if the metabolic flux through the lower part of glycolysis is reduced, to obtain quite high yields for conversion of sugar to 6-MSA. Systems biology tools were employed for in-depth analysis of the metabolic...... are virtually unlimited, and it is thus of great interest to develop a well-described microbial production platform for polyketides. Using genetic engineering tools available for the model organism Aspergillus nidulans, we constructed two recombinant strains, one expressing the Penicillium griseofulvum 6...... processes. Transcriptome analysis of 6-MSA-producing strains grown on glucose and xylose in the presence and absence of xpkA overexpression, combined with flux and physiology data, enabled us to propose an xpkA-msaS interaction model describing the competition between biomass formation and 6-MSA production...

  4. The Aspergillus nidulans cetA and calA genes are involved in conidial germination and cell wall morphogenesis.

    Science.gov (United States)

    Belaish, Ravit; Sharon, Haim; Levdansky, Emma; Greenstein, Shulamit; Shadkchan, Yana; Osherov, Nir

    2008-03-01

    The Aspergillus nidulans genes cetA (AN3079.2) and calA (AN7619.2) encode a novel class of fungal thaumatin-like proteins of unknown function. Deletion of cetA does not result in an observable phenotype [Greenstein, S., Shadkchan, Y., Jadoun, J., Sharon, C., Markovich, S., Osherov, N., 2006. Analysis of the Aspergillus nidulans thaumatin-like cetA gene and evidence for transcriptional repression of pyr4 expression in the cetA-disrupted strain. Fungal Genet. Biol. 43, 42-53]. We prepared knockout calA and calA/cetA A. nidulans strains. The calA mutants were phenotypically identical to the wild-type. In contrast, the cetA/calA double mutant showed a synthetic lethal phenotype suggesting that the two genes affect a single function or pathway: most of its conidia were completely inhibited in germination. Many collapsed and underwent lysis. A few showed abnormal germination characterized by short swollen hyphae and abnormal hyphal branching. Nongerminated conidia contained a single condensed nucleus suggesting a block in early germination. This is the first functional analysis of the novel cetA/calA family of thaumatin-like genes and their role in A. nidulans conidial germination. We show that CETA and CALA are secreted proteins that together play an essential role in early conidial germination. PMID:17703972

  5. Modifying action of DNA synthesis precursors on Aspergillus nidulans conidium irradiated by ultraviolet and X-rays

    International Nuclear Information System (INIS)

    Modification of inactivation action of radiation on conidia Aspergillus nidulans, UVS+ and UVS strains, by desoxynucleosides, purine and pyrimidine bases is shown. The modification manifested in increased conidia survival is revealed when the precursor of DNA synthesis is added to the suspension before exposure to ultraviolet or X-rays. In the case of postradiation application of the substance no modification is observed. The modifying effect of different precursors becomes equally apparent with equimolar solutions and increases at higher concentration of the latter. An increase in thymidine endogenic pool in the exposed conidia does not affect their survival. When conidia are exposed to ultraviolet rays through a thymidine filter the survival rate increases to the same extent as in the case when they are exposed to irradiation in thymidine solution. The authors suggest that modification of the inactivating radiation action by DNA precursors at exposure of conidia Aspergillus nidulans is caused by the radioprotective effect of precursors not related to reparation

  6. A trispecies Aspergillus microarray: Comparative transcriptomics of three Aspergillus species

    DEFF Research Database (Denmark)

    Andersen, Mikael Rørdam; Vongsangnak, Wanwipa; Panagiotou, Gianni; Salazar, Margarita Pena; Lehmann, Linda Olkjær; Nielsen, Jens

    2008-01-01

    The full-genome sequencing of the filamentous fungi Aspergillus nidulans, Aspergillus niger, and Aspergillus oryzae has opened possibilities for studying the cellular physiology of these fungi on a systemic level. As a tool to explore this, we are making available an Affymetrix GeneChip developed...

  7. Aspergillus nidulans Natural Product Biosynthesis Is Regulated by MpkB, a Putative Pheromone Response Mitogen-Activated Protein Kinase

    International Nuclear Information System (INIS)

    The Aspergillus nidulans putative mitogen-activated protein kinase encoded by mpkB has a role in natural product biosynthesis. An mpkB mutant exhibited a decrease in sterigmatocystin gene expression and low mycotoxin levels. The mutation also affected the expression of genes involved in penicillin and terrequinone A synthesis. mpkB was necessary for normal expression of laeA, which has been found to regulate secondary metabolism gene clusters. (author)

  8. Methods for study of induced by ultraviolet irradiation DNA degradation in miceliar fungi after the example of Aspergillus nidulans

    International Nuclear Information System (INIS)

    DNA degradation is shown to take place in conidias and septate mycelium of Aspergillus nidulans after ultraviolet irradiation. However the analysis of degradated DNA, induced by ultraviolet irradiation in conidias is hampered because of DNA instability in control non-irradiated culture. DNA instability at conidia germination is supposed to be the result of metabolic DNA decomposition. DNA instability is not detected in septate mycelium. The study method of DNA degradation induced by ultraviolet irradiation in septate mycelium is suggested

  9. CHPA, a Cysteine- and Histidine-Rich-Domain-Containing Protein, Contributes to Maintenance of the Diploid State in Aspergillus nidulans

    OpenAIRE

    Sadanandom, Ari; Findlay, Kim; Doonan, John H.; Schulze-Lefert, Paul; Shirasu, Ken

    2004-01-01

    The alternation of eukaryotic life cycles between haploid and diploid phases is crucial for maintaining genetic diversity. In some organisms, the growth and development of haploid and diploid phases are nearly identical, and one might suppose that all genes required for one phase are likely to be critical for the other phase. Here, we show that targeted disruption of the chpA (cysteine- and histidine-rich-domain- [CHORD]-containing protein A) gene in haploid Aspergillus nidulans strains gives...

  10. StuAp is a sequence-specific transcription factor that regulates developmental complexity in Aspergillus nidulans.

    OpenAIRE

    J.R. Dutton; Johns, S.; Miller, B.L.

    1997-01-01

    The Aspergillus nidulans Stunted protein (StuAp) regulates multicellular complexity during asexual reproduction by moderating the core developmental program that directs differentiation of uninucleate, terminally differentiated spores from multinucleate, vegetative hyphae. StuAp is also required for ascosporogenesis and multicellular development during sexual reproduction. StuAp is a member of a family of fungal transcription factors that regulate development or cell cycle progression. Furthe...

  11. Diverse Regulation of the CreA Carbon Catabolite Repressor in Aspergillus nidulans.

    Science.gov (United States)

    Ries, Laure N A; Beattie, Sarah R; Espeso, Eduardo A; Cramer, Robert A; Goldman, Gustavo H

    2016-05-01

    Carbon catabolite repression (CCR) is a process that selects the energetically most favorable carbon source in an environment. CCR represses the use of less favorable carbon sources when a better source is available. Glucose is the preferential carbon source for most microorganisms because it is rapidly metabolized, generating quick energy for growth. In the filamentous fungus Aspergillus nidulans, CCR is mediated by the transcription factor CreA, a C2H2 finger domain DNA-binding protein. The aim of this work was to investigate the regulation of CreA and characterize its functionally distinct protein domains. CreA depends in part on de novo protein synthesis and is regulated in part by ubiquitination. CreC, the scaffold protein in the CreB-CreC deubiquitination (DUB) complex, is essential for CreA function and stability. Deletion of select protein domains in CreA resulted in persistent nuclear localization and target gene repression. A region in CreA conserved between Aspergillus spp. and Trichoderma reesei was identified as essential for growth on various carbon, nitrogen, and lipid sources. In addition, a role of CreA in amino acid transport and nitrogen assimilation was observed. Taken together, these results indicate previously unidentified functions of this important transcription factor. These novel functions serve as a basis for additional research in fungal carbon metabolism with the potential aim to improve fungal industrial applications. PMID:27017621

  12. Doxorubicin and etoposide induce somatic recombination in diploid cells of Aspergillus nidulans Doxorubicina e etoposida induzem a recombinação somática em células diplóides de Aspergillus nidulans

    Directory of Open Access Journals (Sweden)

    Simone Jurema Ruggeri Chiuchetta

    2002-09-01

    Full Text Available Doxorubicin and etoposide are intercalating agents that inhibit the action of the enzyme topoisomerase II. Both drugs present therapeutic activity in numerous human neoplasms In the present work the recombinagenic potential of these drugs was evaluated by ascomycete Aspergillus nidulans. Their effects on the asexual cycle of A. nidulans was also appraised. Two heterozygous diploid strains of A. nidulans, a wild (uvsH+//uvsH+ and a defective to the DNA repair (uvsH//uvsH were used. The drugs' recombinagenic potential was evaluated by their capacity to induce homozygosis of recessive genes from heterozygous cells. Both drugs have a recombinagenic effect on diploid cells of A. nidulans. Doxorubicin and etoposide are potentially capable to induce secondary malignancies, mediated by the mitotic crossing-over in eukaryotic cells.Doxorubicina e etoposida são agentes intercalantes que inibem a ação da enzima topoisomerase II. Ambas drogas são amplamente utilizadas no tratamento de neoplasias. O potencial recombinagênico destes agentes e seus efeitos sobre o ciclo assexual de Aspergillus nidulans foram avaliados no presente trabalho. Duas linhagens diplóides heterozigotas foram utilizadas: uma selvagem (uvsH+//uvsH+ e outra deficiente para o reparo do DNA (uvsH//uvsH. O potencial recombinagênico destas drogas foi avaliado pela indução de homozigose de genes recessivos a partir de células heterozigotas. Doxorubicina e etoposida apresentaram efeitos recombinagênicos em ambas linhagens utilizadas. Os resultados permitem concluir que doxorubicina e etoposida são agentes potencialmente capazes de induzir malignidades secundárias, mediadas pelo crossing-over mitótico, em células diplóides eucariotas.

  13. Characterization of a second physiologically relevant lactose permease gene (lacpB) in Aspergillus nidulans.

    Science.gov (United States)

    Fekete, Erzsébet; Orosz, Anita; Kulcsár, László; Kavalecz, Napsugár; Flipphi, Michel; Karaffa, Levente

    2016-05-01

    In Aspergillus nidulans, uptake rather than hydrolysis is the rate-limiting step of lactose catabolism. Deletion of the lactose permease A-encoding gene (lacpA) reduces the growth rate on lactose, while its overexpression enables faster growth than wild-type strains are capable of. We have identified a second physiologically relevant lactose transporter, LacpB. Glycerol-grown mycelia from mutants deleted for lacpB appear to take up only minute amounts of lactose during the first 60 h after a medium transfer, while mycelia of double lacpA/lacpB-deletant strains are unable to produce new biomass from lactose. Although transcription of both lacp genes was strongly induced by lactose, their inducer profiles differ markedly. lacpA but not lacpB expression was high in d-galactose cultures. However, lacpB responded strongly also to β-linked glucopyranose dimers cellobiose and sophorose, while these inducers of the cellulolytic system did not provoke any lacpA response. Nevertheless, lacpB transcript was induced to higher levels on cellobiose in strains that lack the lacpA gene than in a wild-type background. Indeed, cellobiose uptake was faster and biomass formation accelerated in lacpA deletants. In contrast, in lacpB knockout strains, growth rate and cellobiose uptake were considerably reduced relative to wild-type, indicating that the cellulose and lactose catabolic systems employ common elements. Nevertheless, our permease mutants still grew on cellobiose, which suggests that its uptake in A. nidulans prominently involves hitherto unknown transport systems. PMID:26935851

  14. Expression of Aspergillus nidulans phy Gene in Nicotiana benthamiana Produces Active Phytase with Broad Specificities

    Directory of Open Access Journals (Sweden)

    Tae-Kyun Oh

    2014-09-01

    Full Text Available A full-length phytase gene (phy of Aspergillus nidulans was amplified from the cDNA library by polymerase chain reaction (PCR, and it was introduced into a bacterial expression vector, pET-28a. The recombinant protein (rPhy-E, 56 kDa was overexpressed in the insoluble fraction of Escherichia coli culture, purified by Ni-NTA resin under denaturing conditions and injected into rats as an immunogen. To express A. nidulans phytase in a plant, the full-length of phy was cloned into a plant expression binary vector, pPZP212. The resultant construct was tested for its transient expression by Agrobacterium-infiltration into Nicotiana benthamiana leaves. Compared with a control, the agro-infiltrated leaf tissues showed the presence of phy mRNA and its high expression level in N. benthamiana. The recombinant phytase (rPhy-P, 62 kDa was strongly reacted with the polyclonal antibody against the nonglycosylated rPhy-E. The rPhy-P showed glycosylation, two pH optima (pH 4.5 and pH 5.5, an optimum temperature at 45~55 °C, thermostability and broad substrate specificities. After deglycosylation by peptide-N-glycosidase F (PNGase-F, the rPhy-P significantly lost the phytase activity and retained 1/9 of the original activity after 10 min of incubation at 45 °C. Therefore, the deglycosylation caused a significant reduction in enzyme thermostability. In animal experiments, oral administration of the rPhy-P at 1500 U/kg body weight/day for seven days caused a significant reduction of phosphorus excretion by 16% in rat feces. Besides, the rPhy-P did not result in any toxicological changes and clinical signs.

  15. Functional characterization of Aspergillus nidulans ypkA, a homologue of the mammalian kinase SGK.

    Science.gov (United States)

    Colabardini, Ana Cristina; Brown, Neil Andrew; Savoldi, Marcela; Goldman, Maria Helena S; Goldman, Gustavo Henrique

    2013-01-01

    The serum- and glucocorticoid-regulated protein kinase (SGK) is an AGC kinase involved in signal cascades regulated by glucocorticoid hormones and serum in mammals. The Saccharomyces cerevisiae ypk1 and ypk2 genes were identified as SGK homologues and Ypk1 was shown to regulate the balance of sphingolipids between the inner and outer plasma membrane. This investigation characterized the Aspergillus nidulans YPK1 homologue, YpkA, representing the first filamentous fungal YPK1 homologue. Two conditional mutant strains were constructed by replacing the endogenous ypk1 promoter with two different regulatable promoters, alcA (from the alcohol dehydrogenase gene) and niiA (from the nitrate reductase gene). Both constructs confirmed that ypkA was an essential gene in A. nidulans. Repression of ypkA caused decreased radial growth, a delay in conidial germination, deficient polar axis establishment, intense branching during late stages of growth, a lack of asexual spores, and a terminal phenotype. Membrane lipid polarization, endocytosis, eisosomes and vacuolar distribution were also affected by ypkA repression, suggesting that YpkA plays a role in hyphal morphogenesis via coordinating the delivery of cell membrane and wall constituents to the hyphal apex. The A. nidulans Pkh1 homologue pkhA was also shown to be an essential gene, and preliminary genetic analysis suggested that the ypkA gene is not directly downstream of pkhA or epistatic to pkhA, rather, ypkA and pkhA are genetically independent or in parallel. BarA is a homologue of the yeast Lag1 acyl-CoA-dependent ceramide synthase, which catalyzes the condensation of phytosphingosine with a fatty acyl-CoA to form phytoceramide. When barA was absent, ypkA repression was lethal to the cell. Therefore, there appears to be a genetic interaction between ypkA, barA, and the sphingolipid synthesis. Transcriptional profiling of ypkA overexpression and down-regulation revealed several putative YpkA targets associated with the

  16. Cremophor EL stimulates mitotic recombination in uvsH//uvsH diploid strain of Aspergillus nidulans

    Directory of Open Access Journals (Sweden)

    Cleverson Busso

    2004-03-01

    Full Text Available Cremophor EL is a solubilizer and emulsifier agent used in the pharmaceutical and foodstuff industries. The solvent is the principal constituent of paclitaxel's clinical formulation vehicle. Since mitotic recombination plays a crucial role in multistep carcinogenesis, the study of the recombinagenic potential of chemical compounds is of the utmost importance. In our research genotoxicity of cremophor EL has been studied by using an uvsH//uvsH diploid strain of Aspergillus nidulans. Since it spends a great part of its cell cycle in the G2period, this fungus is a special screening system for the study of mitotic recombination induced by chemical substances. Homozygotization Indexes (HI for paba and bi markers from heterozygous B211//A837 diploid strain were determined for the evaluation of the recombinagenic effect of cremophor EL. It has been shown that cremophor EL induces increase in mitotic crossing-over events at nontoxic concentrations (0.05 and 0.075% v/v.Cremofor EL (CEL é um solubilizante e emulsificante amplamente utilizado nas indústrias farmacêuticas e de gêneros alimentícios. É o principal veículo empregado nas formulações clínicas do antineoplásico paclitaxel. Considerando-se que a recombinação mitótica desempenha importante função no processo de carcinogênese, o estudo de substâncias químicas com potencial recombinagênico assume importância crucial, no sentido de se detectar aquelas que eventualmente possam atuar como promotoras de neoplasias. A genotoxicidade do cremofor EL foi estudada no presente trabalho, utilizando-se uma linhagem diplóide uvsH//uvsH de Aspergillus nidulans. Neste fungo as células vegetativas comumente repousam no período G2 do ciclo celular, facilitando a ocorrência da recombinação mitótica. O efeito recombinagênico do CEL foi avaliado através da determinação dos Índices de Homozigotização para os marcadores nutricionais paba e bi do diplóide heterozigoto B211//A837. Os

  17. A genomics based discovery of secondary metabolite biosynthetic gene clusters in Aspergillus ustus.

    Directory of Open Access Journals (Sweden)

    Borui Pi

    Full Text Available Secondary metabolites (SMs produced by Aspergillus have been extensively studied for their crucial roles in human health, medicine and industrial production. However, the resulting information is almost exclusively derived from a few model organisms, including A. nidulans and A. fumigatus, but little is known about rare pathogens. In this study, we performed a genomics based discovery of SM biosynthetic gene clusters in Aspergillus ustus, a rare human pathogen. A total of 52 gene clusters were identified in the draft genome of A. ustus 3.3904, such as the sterigmatocystin biosynthesis pathway that was commonly found in Aspergillus species. In addition, several SM biosynthetic gene clusters were firstly identified in Aspergillus that were possibly acquired by horizontal gene transfer, including the vrt cluster that is responsible for viridicatumtoxin production. Comparative genomics revealed that A. ustus shared the largest number of SM biosynthetic gene clusters with A. nidulans, but much fewer with other Aspergilli like A. niger and A. oryzae. These findings would help to understand the diversity and evolution of SM biosynthesis pathways in genus Aspergillus, and we hope they will also promote the development of fungal identification methodology in clinic.

  18. Allergens/Antigens, Toxins and Polyketides of Important Aspergillus Species

    OpenAIRE

    Bhetariya, Preetida J.; Madan, Taruna; Basir, Seemi Farhat; Varma, Anupam; Usha, Sarma P.

    2011-01-01

    The medical, agricultural and biotechnological importance of the primitive eukaryotic microorganisms, the Fungi was recognized way back in 1920. Among various groups of fungi, the Aspergillus species are studied in great detail using advances in genomics and proteomics to unravel biological and molecular mechanisms in these fungi. Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, Aspergillus parasiticus, Aspergillus nidulans and Aspergillus terreus are some of the important specie...

  19. Antimutagenic action of Lentinula edodes and Agaricus blazei on Aspergillus nidulans conidia Ação antimutagênica de Lentinula edodes e Agaricus blazei em conídios de Aspergillus nidulans

    Directory of Open Access Journals (Sweden)

    Edneia A. Souza-Paccola

    2004-12-01

    Full Text Available The antimutagenic effect of the mushrooms Lentinula edodes and Agaricus blazei was studied on conidia of Aspergillus nidulans when exposed to short wave ultraviolet light. Two strains of A. nidulans were used. For the preparation of the extracts, the fresh mushrooms were left in aqueous infusion for 12 hours and heated in a water bath for 15 min at 100ºC, and then the material was filtered. The dehydrated mushrooms were left in aqueous infusion for 12 hours and to filtrated. Both filtrates were used as extracts. A. nidulans conidia were incubated for three hours in water and in mushroom extracts and only after were exposed to UV light (pre-treatment. A. nidulans conidia were suspended in water and in mushroom extracts and immediately submitted to UV light (post-treatment. Conidial suspension in water and in mushroom extracts but without exposure to the mutagenic agent were used as controls. After mutagenic treatment, it was observed an increase in the survival rate of the A. nidulans and a decrease in the percentage of morphologic mutants on conidia treated with mushroom extracts. Our results demonstrated the radioprotective and antimutagenic effect of L. edodes and A. blazei mushrooms on eukaryotic cells when exposed to UV radiation.O efeito antimutagênico dos cogumelos Lentinula edodes e Agaricus blazei foram estudados sobre conídios de Aspergillus nidulans quando expostos à luz ultravioleta de comprimento de onda curto. Duas linhagens de A. nidulans foram usadas. Para o preparo dos extratos, os cogumelos frescos permaneceram em infusão aquosa por 12 horas e em seguida foram aquecidos em banho-maria por 15 min à 100ºC e a seguir o material foi filtrado. Os cogumelos desidratados foram deixados em infusão aquosa por 12 horas e a seguir filtrados. Ambos os filtrados foram usados como extratos. Os conídios de A. nidulans foram incubados por três horas em água e em extrato de cogumelo e somente após foram expostos a luz ultravioleta

  20. Cross-talk between light and glucose regulation controls toxin production and morphogenesis in Aspergillus nidulans

    International Nuclear Information System (INIS)

    Light is a major environmental stimulus that has a broad effect on organisms, triggering a cellular response that results in an optimal adaptation enhancing fitness and survival. In fungi, light affects growth, and causes diverse morphological changes such as those leading to reproduction. Light can also affect fungal metabolism, including the biosynthesis of natural products. In this study we show that in Aspergillus nidulans the effect of light on the production of the sterigmatocystin (ST) toxin depends on the glucose concentration. In cultures grown with 1% glucose and exposed to light, ST production was lower than when grown in the dark. This lower ST production coincided with an elevated rate of cellular damage with partial loss of nuclear integrity and vacuolated cytoplasm. However, in cultures grown with 2% glucose these effects were reversed and light enhanced ST production. Glucose abundance also affected the light-dependent subcellular localization of the VeA (velvet) protein, a key regulator necessary for normal light-dependent morphogenesis and secondary metabolism in Aspergilli and other fungal gen- era. The role of other VeA-associated proteins, particularly the blue-light-sensing proteins LreA and LreB (WC-1 and WC-2 orthologs), on conidiation could also be modified by the abundance of glucose. We also show that LreA and LreB, as well as the phytochrome FphA, modulate not only the synthesis of sterigmat- ocystin, but also the production of the antibiotic penicillin. (author)

  1. Dynamics of actin cables in polarized growth of the filamentous fungus Aspergillus nidulans

    Directory of Open Access Journals (Sweden)

    Anna eBergs

    2016-05-01

    Full Text Available Highly polarized growth of filamentous fungi requires a continuous supply of proteins and lipids to the hyphal tip. This transport is managed by vesicle trafficking via the actin and microtubule cytoskeletons and their associated motor proteins. Particularly, actin cables originating from the hyphal tip are essential for hyphal growth. Although specific marker proteins to visualize actin cables have been developed in filamentous fungi, the exact organization and dynamics of actin cables has remained elusive. Here we visualized actin cables using tropomyosin (TpmA and Lifeact fused to fluorescent proteins in Aspergillus nidulans and studied the dynamics and regulation. GFP tagged TpmA visualized dynamic actin cables formed from the hyphal tip with cycles of elongation and shrinkage. The elongation and shrinkage rates of actin cables were similar and approximately 0.6 μm/s. Comparison of actin markers revealed that high concentrations of Lifeact reduced actin dynamics. Simultaneous visualization of actin cables and microtubules suggests temporally and spatially coordinated polymerization and depolymerization between the two cytoskeletons. Our results provide new insights into the molecular mechanism of ordered polarized growth regulated by actin cables and microtubules.

  2. Live Cell Imaging of Actin Dynamics in the Filamentous Fungus Aspergillus nidulans.

    Science.gov (United States)

    Schultzhaus, Zachary; Quintanilla, Laura; Hilton, Angelyn; Shaw, Brian D

    2016-04-01

    Hyphal cells of filamentous fungi grow at their tips in a method analogous to pollen tube and root hair elongation. This process, generally referred to as tip growth, requires precise regulation of the actin cytoskeleton, and characterizing the various actin structures in these cell types is currently an active area of research. Here, the actin marker Lifeact was used to document actin dynamics in the filamentous fungus Aspergillus nidulans. Contractile double rings were observed at septa, and annular clusters of puncta were seen subtending growing hyphal tips, corresponding to the well-characterized subapical endocytic collar. However, Lifeact also revealed two additional structures. One, an apical array, was dynamic on the face opposite the tip, while a subapical web was dynamic on the apical face and was located several microns behind the growth site. Each was observed turning into the other over time, implying that they could represent different localizations of the same structure, although hyphae with a subapical web grew faster than those exhibiting an apical array. The subapical web has not been documented in any filamentous fungus to date, and is separate from the networks of F-actin seen in other tip-growing organisms surrounding septa or stationary along the plasmalemma. PMID:26879694

  3. Dynamics of Actin Cables in Polarized Growth of the Filamentous Fungus Aspergillus nidulans

    Science.gov (United States)

    Bergs, Anna; Ishitsuka, Yuji; Evangelinos, Minoas; Nienhaus, G. U.; Takeshita, Norio

    2016-01-01

    Highly polarized growth of filamentous fungi requires a continuous supply of proteins and lipids to the hyphal tip. This transport is managed by vesicle trafficking via the actin and microtubule cytoskeletons and their associated motor proteins. Particularly, actin cables originating from the hyphal tip are essential for hyphal growth. Although, specific marker proteins have been developed to visualize actin cables in filamentous fungi, the exact organization and dynamics of actin cables has remained elusive. Here, we observed actin cables using tropomyosin (TpmA) and Lifeact fused to fluorescent proteins in living Aspergillus nidulans hyphae and studied the dynamics and regulation. GFP tagged TpmA visualized dynamic actin cables formed from the hyphal tip with cycles of elongation and shrinkage. The elongation and shrinkage rates of actin cables were similar and approximately 0.6 μm/s. Comparison of actin markers revealed that high concentrations of Lifeact reduced actin dynamics. Simultaneous visualization of actin cables and microtubules suggests temporally and spatially coordinated polymerization and depolymerization between the two cytoskeletons. Our results provide new insights into the molecular mechanism of ordered polarized growth regulated by actin cables and microtubules.

  4. Cloning and Characterization of Filamentous Fungal S-Nitrosoglutathione Reductase from Aspergillus nidulans.

    Science.gov (United States)

    Zhou, Yao; Zhou, Shengmin; Yu, Haijun; Li, Jingyi; Xia, Yang; Li, Baoyi; Wang, Xiaoli; Wang, Ping

    2016-05-28

    S-Nitrosoglutathione reductase (GSNOR) metabolizes S-nitrosoglutathione (GSNO) and has been shown to play important roles in regulating cellular signaling and formulating host defense by modulating intracellular nitric oxide levels. The enzyme has been found in bacterial, yeast, mushroom, plant, and mammalian cells. However, to date, there is still no evidence of its occurrence in filamentous fungi. In this study, we cloned and investigated a GSNOR-like enzyme from the filamentous fungus Aspergillus nidulans. The enzyme occurred in native form as a homodimer and exhibited low thermal stability. GSNO was an ideal substrate for the enzyme. The apparent Km and kcat values were 0.55 mM and 34,100 min(-1), respectively. Substrate binding sites and catalytic center amino acid residues based on those from known GSNORs were conserved in this enzyme, and the corresponding roles were verified using site-directed mutagenesis. Therefore, we demonstrated the presence of GSNOR in a filamentous fungus for the first time. PMID:26869606

  5. Identificação do potencial amilolítico de linhagens mutantes do fungo filamentoso Aspergillus nidulans Identification of the amylolytic potential of mutant strains of the filamentous fungi Aspergillus nidulans

    Directory of Open Access Journals (Sweden)

    Izabel Aparecida Soares

    2010-09-01

    Full Text Available As amilases estão entre as mais importantes enzimas industriais, apresentando grande importância biotecnológica, principalmente na indústria alimentícia. Com o avanço no conhecimento das enzimas, a utilização dos fungos como fonte de enzimas vem adquirindo um status de destaque nas mais variadas áreas industriais e comerciais. Diante disso, o presente estudo procurou identificar a presença de atividade amilolítica em quatro linhagens do fungo filamentoso Aspergillus nidulans, selvagem, PAT, biA1methG1 e CLB3, utilizando dois meios distintos de cultura, BDA e Meio Completo a 2% amido, variando os tratamentos com adição ou não de glicose. Foram determinados o diâmetro médio da colônia, o diâmetro médio do halo e o Índice Enzimático. Como resultados, todas as linhagens testadas foram capazes de degradar o amido quando na ausência de glicose, porém o tratamento que obteve estatisticamente melhor crescimento e maior degradação do amido foi o MC sem glicose a 2% amido e a linhagem que se demonstrou potencialmente degradadora de amido foi o mutante CLB3. Conclui-se, portanto, que Aspergillus nidulans pode ser considerado como um produtor de amilases.The amylases are among the most important industrial enzymes showing great biotechnological importance, mainly in the food industry. Due to the advance knowledge in enzyme research, the use of fungi as source of enzymes has acquired a prominent status in most varied industrial and commercial areas. Thus, the present study tried to identify the presence of the amylolytic activity in four stains of filamentous fungi Aspergillus nidulans, selvagem, PAT, biA1methG1 and CLB3 by using two different culture means, PDA and Complete mean with 2% starch, varying the treatments with and without the addition of glucose. The colony average diameter, the halo average diameter, and the enzymatic index were determined. The results show that all strains tested were capable of degrading starch in the

  6. Gmca is a putative glucose-methanol-choline oxidoreductase required for the induction of asexual development in aspergillus nidulans

    OpenAIRE

    Oier Etxebeste; Erika Herrero-García; Cortese, Marc S.; Aitor Garzia; Elixabet Oiartzabal-Arano; Vivian de los Ríos; Unai Ugalde; Espeso, Eduardo A.

    2012-01-01

    Aspergillus nidulans asexual differentiation is induced by Upstream Developmental Activators (UDAs) that include the bZIP-type Transcription Factor (TF) FlbB. A 2D-PAGE/MS-MS-coupled screen for proteins differentially expressed in the presence and absence of FlbB identified 18 candidates. Most candidates belong to GO term classes involved in osmotic and/or oxidative stress response. Among these, we focused on GmcA, a putative glucose-methanol-choline oxidoreductase which is upregulated in a Δ...

  7. Mlp1 Acts as a Mitotic Scaffold to Spatially Regulate Spindle Assembly Checkpoint Proteins in Aspergillus nidulans

    OpenAIRE

    De Souza, Colin P.; Hashmi, Shahr B.; Nayak, Tania; Oakley, Berl; Osmani, Stephen A.

    2009-01-01

    During open mitosis several nuclear pore complex (NPC) proteins have mitotic specific localizations and functions. We find that the Aspergillus nidulans Mlp1 NPC protein has previously unrealized mitotic roles involving spatial regulation of spindle assembly checkpoint (SAC) proteins. In interphase, An-Mlp1 tethers the An-Mad1 and An-Mad2 SAC proteins to NPCs. During a normal mitosis, An-Mlp1, An-Mad1, and An-Mad2 localize similarly on, and around, kinetochores until telophase when they trans...

  8. Identification of the sites of action for regulatory genes controlling the amdS gene of Aspergillus nidulans.

    OpenAIRE

    Hynes, M J; Corrick, C M; Kelly, J M; Littlejohn, T G

    1988-01-01

    The amdS gene of Aspergillus nidulans, which encodes an acetamidase enzyme, is positively regulated by the trans-acting genes amdR, facB, amdA, and areA. Sequence changes in several cis-acting mutations in the 5' region of the gene which specifically affect amdS regulation were determined. The amdI9 mutation, which results in increased facB-dependent acetate induction, is due to a single-base change at base pair -210 relative to the start point of translation. The amdI93 mutation, which aboli...

  9. FlbD, a Myb Transcription Factor of Aspergillus nidulans, Is Uniquely Involved in both Asexual and Sexual Differentiation

    OpenAIRE

    Arratia-Quijada, Jenny; Sánchez, Olivia; Scazzocchio, Claudio; Aguirre, Jesús

    2012-01-01

    In the fungus Aspergillus nidulans, inactivation of the flbA to -E, fluG, fluF, and tmpA genes results in similar phenotypes, characterized by a delay in conidiophore and asexual spore production. flbB to -D encode transcription factors needed for proper expression of the brlA gene, which is essential for asexual development. However, recent evidence indicates that FlbB and FlbE also have nontranscriptional functions. Here we show that fluF1 is an allele of flbD which results in an R47P subst...

  10. The formamidase gene of Aspergillus nidulans: regulation by nitrogen metabolite repression and transcriptional interference by an overlapping upstream gene.

    OpenAIRE

    Fraser, J A; Davis, M A; Hynes, M J

    2001-01-01

    The ability to utilize formamide as a sole nitrogen source has been found in numerous fungi. We have cloned the fmdS gene encoding a formamidase from Aspergillus nidulans and found that it belongs to a highly conserved family of proteins separate from the major amidase families. The expression of fmdS is primarily regulated via AreA-mediated nitrogen metabolite repression and does not require the addition of exogenous inducer. Consistent with this, deletion analysis of the 5' region of fmdS h...

  11. Physiological characterisation of recombinant Aspergillus nidulans strains with different creA genotypes expressing A-oryzae alpha-amylase

    DEFF Research Database (Denmark)

    Agger, Teit; Petersen, J.B.; O'Connor, S.M.; Murphy, R.L.; Kelly, J.M.; Nielsen, Jette

    2002-01-01

    The physiology of three strains of Aspergillus nidulans was examined-a creA deletion strain, a wild type creA genotype and a strain containing extra copies of the creA gene, all producing Aspergillus oryzae alpha-amylase. The strains were cultured in batch and continuous cultivations and the...... biomass formation and alpha-amylase production was characterised. Overexpression of the creA gene resulted in a lower maximum specific growth rate and a slightly higher repression of the alpha-amylase production during conditions with high glucose concentration. No expression of creA also resulted in a...... sources on the alpha-amylase production in the creA deletion strain was investigated and it was found that starch was the best inducer. The degree of induction by starch increased almost linearly with the concentration of starch in starch/glucose mixtures. High-density batch cultivation was performed with...

  12. Recombinant production and characterisation of two related GH5 endo-β-1,4-mannanases from Aspergillus nidulans FGSC A4 showing distinctly different transglycosylation capacity

    DEFF Research Database (Denmark)

    Dilokpimol, Adiphol; Nakai, Hiroyuki; Gotfredsen, Charlotte Held;

    2011-01-01

    The glycoside hydrolase family 5 (GH5) endo-β-1,4-mannanases ManA and ManC from Aspergillus nidulans FGSC A4 were produced in Pichia pastoris X33 and purified in high yields of 120 and 145mg/L, respectively, from the culture supernatants. Both enzymes showed increasing catalytic efficiency (kcat...

  13. A WDR Gene Is a Conserved Member of a Chitin Synthase Gene Cluster and Influences the Cell Wall in Aspergillus nidulans

    Science.gov (United States)

    Guerriero, Gea; Silvestrini, Lucia; Obersriebnig, Michael; Hausman, Jean-Francois; Strauss, Joseph; Ezcurra, Inés

    2016-01-01

    WD40 repeat (WDR) proteins are pleiotropic molecular hubs. We identify a WDR gene that is a conserved genomic neighbor of a chitin synthase gene in Ascomycetes. The WDR gene is unique to fungi and plants, and was called Fungal Plant WD (FPWD). FPWD is within a cell wall metabolism gene cluster in the Ascomycetes (Pezizomycotina) comprising chsD, a Chs activator and a GH17 glucanase. The FPWD, AN1556.2 locus was deleted in Aspergillus nidulans strain SAA.111 by gene replacement and only heterokaryon transformants were obtained. The re-annotation of Aspergilli genomes shows that AN1556.2 consists of two tightly linked separate genes, i.e., the WDR gene and a putative beta-flanking gene of unknown function. The WDR and the beta-flanking genes are conserved genomic neighbors localized within a recently identified metabolic cell wall gene cluster in genomes of Aspergilli. The heterokaryons displayed increased susceptibility to drugs affecting the cell wall, and their phenotypes, observed by optical, confocal, scanning electron and atomic force microscopy, suggest cell wall alterations. Quantitative real-time PCR shows altered expression of some cell wall-related genes. The possible implications on cell wall biosynthesis are discussed. PMID:27367684

  14. Comparative Reannotation of 21 Aspergillus Genomes

    Energy Technology Data Exchange (ETDEWEB)

    Salamov, Asaf; Riley, Robert; Kuo, Alan; Grigoriev, Igor

    2013-03-08

    We used comparative gene modeling to reannotate 21 Aspergillus genomes. Initial automatic annotation of individual genomes may contain some errors of different nature, e.g. missing genes, incorrect exon-intron structures, 'chimeras', which fuse 2 or more real genes or alternatively splitting some real genes into 2 or more models. The main premise behind the comparative modeling approach is that for closely related genomes most orthologous families have the same conserved gene structure. The algorithm maps all gene models predicted in each individual Aspergillus genome to the other genomes and, for each locus, selects from potentially many competing models, the one which most closely resembles the orthologous genes from other genomes. This procedure is iterated until no further change in gene models is observed. For Aspergillus genomes we predicted in total 4503 new gene models ( ~;;2percent per genome), supported by comparative analysis, additionally correcting ~;;18percent of old gene models. This resulted in a total of 4065 more genes with annotated PFAM domains (~;;3percent increase per genome). Analysis of a few genomes with EST/transcriptomics data shows that the new annotation sets also have a higher number of EST-supported splice sites at exon-intron boundaries.

  15. Genetic involvement of a cAMP-dependent protein kinase in a G protein signaling pathway regulating morphological and chemical transitions in Aspergillus nidulans.

    OpenAIRE

    Shimizu, K; Keller, N P

    2001-01-01

    In the filamentous fungus Aspergillus nidulans, a heterotrimeric G protein alpha-subunit and an RGS domain protein, encoded by fadA and flbA, respectively, regulate production of the carcinogenic metabolite sterigmatocystin (ST) and asexual spores (i.e., conidia). We investigated the genetic involvement of the cAMP-dependent protein kinase catalytic subunit (PkaA), a potential downstream target of FadA activity, in ST production and conidiation. Relative to wild type, sporulation was decrease...

  16. Aspergillus nidulans transcription factor AtfA interacts with the MAPK SakA to regulate general stress responses, development and spore functions

    OpenAIRE

    Lara-Rojas, Fernando; Sánchez, Olivia; Kawasaki, Laura; Aguirre, Jesús

    2011-01-01

    Fungi utilize a phosphorelay system coupled to a MAP kinase module for sensing and processing environmental signals. In Aspergillus nidulans, response regulator SskA transmits osmotic and oxidative stress signals to the stress MAPK (SAPK) SakA. Using a genetic approach together with GFP tagging and molecular bifluorescence we show that SakA and ATF/CREB transcription factor AtfA define a general stress-signalling pathway that plays differential roles in oxidative stress responses during growt...

  17. Position-dependent and -independent mechanisms regulate cell-specific expression of the SpoC1 gene cluster of Aspergillus nidulans.

    OpenAIRE

    Miller, B.L.; Miller, K. Y.; Roberti, K A; Timberlake, W E

    1987-01-01

    Many genes that are expressed specifically in the differentiating asexual spores (conidia) of Aspergillus nidulans are organized into clusters. We investigated the effects of altered chromosomal position on expression of a gene from the conidiation-specific SpoC1 gene cluster. The gene became deregulated when integrated at nonhomologous chromosomal sites, in that transcript levels were elevated in vegetative cells (hyphae) and variably altered in conidia. We also investigated the effects on e...

  18. The pH dependence of the mutagenicity of methyl benzimidazol-2-yl carbamate (MBC) towards Aspergillus nidulans (Eidam) Winter and Cladosporium cucumerinum Ellis & Arth.

    Science.gov (United States)

    Nirenberg, H I; Speakman, J B

    1981-01-01

    The ability of methyl benzimidazol-2-yl carbamate (MBC) to induce point mutations to carboxin and MBC resistance in Aspergillus nidulans (Eidam) Winter and Cladosporium cucumerinum Ellis & Arth. was dependent upon the pH value of the agar medium into which it had been incorporated. The relevance of this in relation to testing chemicals for a possible mutagenic activity with microorganisms is discussed. PMID:7010148

  19. Physiological characterisation of recombinant Aspergillus nidulans strains with different creA genotypes expressing A. oryzae alpha-amylase.

    Science.gov (United States)

    Agger, Teit; Petersen, Jesper B; O'Connor, Susan M; Murphy, Rachael L; Kelly, Joan M; Nielsen, Jens

    2002-01-18

    The physiology of three strains of Aspergillus nidulans was examined--a creA deletion strain, a wild type creA genotype and a strain containing extra copies of the creA gene, all producing Aspergillus oryzae alpha-amylase. The strains were cultured in batch and continuous cultivations and the biomass formation and alpha-amylase production was characterised. Overexpression of the creA gene resulted in a lower maximum specific growth rate and a slightly higher repression of the alpha-amylase production during conditions with high glucose concentration. No expression of creA also resulted in a decreased maximum specific growth rate, but also in drastic changes in morphology. Furthermore, the expression of alpha-amylase was completely derepressed and creA thus seems to be the only regulatory protein responsible for glucose repression of alpha-amylase expression. The effect of different carbon sources on the alpha-amylase production in the creA deletion strain was investigated and it was found that starch was the best inducer. The degree of induction by starch increased almost linearly with the concentration of starch in starch/glucose mixtures. High-density batch cultivation was performed with the creA deletion strain and a final titre of 6.0 g l(-1) of alpha-amylase was reached after 162 h of cultivation. PMID:11689252

  20. acon-3, the Neurospora crassa ortholog of the developmental modifier, medA, complements the conidiation defect of the Aspergillus nidulans mutant.

    Science.gov (United States)

    Chung, Da-Woon; Greenwald, Charles; Upadhyay, Srijana; Ding, Shengli; Wilkinson, Heather H; Ebbole, Daniel J; Shaw, Brian D

    2011-04-01

    Aspergillus nidulans and Neurospora crassa are ascomycetes that produce asexual spores through morphologically distinct processes. MedA, a protein with unknown function, is required for normal asexual and sexual development in A. nidulans. We determined that the N. crassa ortholog of medA is acon-3, a gene required for early conidiophore development and female fertility. To test hypotheses about the evolutionary origins of asexual development in distinct fungal lineages it is important to understand the degree of conservation of developmental regulators. The amino acid sequences of A. nidulans MedA and N. crassa ACON-3 shared 37% identity and 51% similarity. acon-3 is induced at late time points of conidiation. In contrast, medA is constitutively expressed and MedA protein localizes to nuclei in all tissue types. Nonetheless, expression of acon-3 using its native promoter complemented the conidiation defects of the A. nidulans ΔmedA and medA15 mutants. We conclude that the biochemical activity of the medA orthologs is conserved for conidiation. PMID:21220038

  1. Expression and secretion in Aspergillus nidulans and Aspergillus niger of a cell surface glycoprotein from the cattle tick, Boophilus microplus, by using the fungal amdS promoter system.

    OpenAIRE

    Turnbull, I F; Smith, D R; Sharp, P. J.; Cobon, G S; Hynes, M J

    1990-01-01

    A cell surface glycoprotein (Bm86) from cells of the digestive tract of the cattle tick Boophilus microplus, which has been shown to elicit a protective immunological response in vaccinated cattle, was expressed and secreted in the filamentous fungi Aspergillus nidulans and Aspergillus niger by using the fungal amdS promoter system. The cloned gene coded for the Bm86 secretory signal and all of the Bm86 mature polypeptide except for the hydrophobic carboxy-terminal segment. High levels of Bm8...

  2. Identificación de la quinasa HalA y el estudio de su papel en la regulación de la homeostasis de cationes en Aspergillus nidulans

    OpenAIRE

    Cobeño Fariñas, Laura

    2010-01-01

    Aspergillus nidulans es un hongo filamentoso que presenta un tipo de crecimiento hiperpolarizado formando largos filamentos denominados hifas y muestra ramificación lateral en los compartimentos celulares más posteriores de la hifa. El genoma de A. nidulans se publicó en diciembre de 2005. La disponibilidad de dicha información es una nueva e importante herramienta de trabajo y supone un avance significativo que permitirá seguir utilizando A. nidulans como organismo modelo, genéticamente mani...

  3. Co-cultivation of Aspergillus nidulans recombinant strains produces an enzymatic cocktail as alternative to alkaline sugarcane bagasse pretreatment

    Directory of Open Access Journals (Sweden)

    Matheus Sanita Lima

    2016-04-01

    Full Text Available Plant materials represent a strategic energy source because they can give rise to sustainable biofuels through the fermentation of their carbohydrates. A clear example of a plant-derived biofuel resource is the sugar cane bagasse exhibiting 60 % - 80 % of fermentable sugars in its composition. However, the current methods of plant bioconversion employ severe and harmful chemical/physical pretreatments raising biofuel cost production and environmental degradation. Replacing these methods with co-cultivated enzymatic cocktails is an alternative. Here we propose a pretreatment for sugarcane bagasse using a multi-enzymatic cocktail from the co-cultivation of four Aspergillus nidulans recombinant strains. The co-cultivation resulted in the simultaneous production of GH51 arabinofuranosidase (AbfA, GH11 endo-1,4-xylanase (XlnA, GH43 endo-1,5-arabinanase (AbnA and GH12 xyloglucan specific endo-β-1,4-glucanase (XegA. This core set of recombinant enzymes was more efficient than the alternative alkaline method in maintaining the cellulose integrity and exposing this cellulose to the following saccharification process. Thermogravimetric and differential thermal analysis revealed residual byproducts on the alkali pretreated biomass, which were not found in the enzymatic pretreatment. Therefore, the enzymatic pretreatment was residue-free and seemed to be more efficient than the applied alkaline method, which makes it suitable for bioethanol production.

  4. Genetic control of chromosome instability in Aspergillus nidulans as a means for gene amplification in eukaryotic microorganisms

    International Nuclear Information System (INIS)

    A haploid strain of Aspergillus nidulans carrying I-II duplication homozygous for the leaky mutation adE20 shows improved growth on minimal medium. The duplication, though more stable than disomics, still shows instability. Several methods were used for detecting genetic control of improved stability. a) visual selection, using a duplicated strain which is very unstable due to UV sensitivity, (adE20, biAl/dp yA2; uvsB). One stable strain showed a deletion (or a lethal mutation) distal to biA on the segment at the original position (on chromosome I). This deletion reduces crossing-over frequency detween the two homologous segments. As the deletion of the non-translated segment (yellow sectors) must be preceded by crossing-over, the above reduces the frequency of yellow sectors. A deletion of the translocated segment (green sectors) results in non-viability due to the deletion, and such sectors do not appear. The net result is a stable duplication involving only 12 C.O. units carrying the gene in concern. b) Suppressors of UV sensitivity (su-uvsB) were attempted using the above uvs duplicated strain. Phenotypic revertants were easily obtained, but all were back mutations at the uvsB locus. c) Mutations for UV resistance higher than that of the wild type were not obtained, in spite of the strong selective pressure inserted. d) Recombination deficient mutations (rec), six altogether, all uvs+, did not have any effect on stability. (orig.)

  5. Co-cultivation of Aspergillus nidulans Recombinant Strains Produces an Enzymatic Cocktail as Alternative to Alkaline Sugarcane Bagasse Pretreatment.

    Science.gov (United States)

    Lima, Matheus S; Damasio, André R de L; Crnkovic, Paula M; Pinto, Marcelo R; da Silva, Ana M; da Silva, Jean C R; Segato, Fernando; de Lucas, Rosymar C; Jorge, João A; Polizeli, Maria de L T de M

    2016-01-01

    Plant materials represent a strategic energy source because they can give rise to sustainable biofuels through the fermentation of their carbohydrates. A clear example of a plant-derived biofuel resource is the sugar cane bagasse exhibiting 60-80% of fermentable sugars in its composition. However, the current methods of plant bioconversion employ severe and harmful chemical/physical pretreatments raising biofuel cost production and environmental degradation. Replacing these methods with co-cultivated enzymatic cocktails is an alternative. Here we propose a pretreatment for sugarcane bagasse using a multi-enzymatic cocktail from the co-cultivation of four Aspergillus nidulans recombinant strains. The co-cultivation resulted in the simultaneous production of GH51 arabinofuranosidase (AbfA), GH11 endo-1,4-xylanase (XlnA), GH43 endo-1,5-arabinanase (AbnA) and GH12 xyloglucan specific endo-β-1,4-glucanase (XegA). This core set of recombinant enzymes was more efficient than the alternative alkaline method in maintaining the cellulose integrity and exposing this cellulose to the following saccharification process. Thermogravimetric and differential thermal analysis revealed residual byproducts on the alkali pretreated biomass, which were not found in the enzymatic pretreatment. Therefore, the enzymatic pretreatment was residue-free and seemed to be more efficient than the applied alkaline method, which makes it suitable for bioethanol production. PMID:27199917

  6. An Aspergillus nidulans GH26 endo-β-mannanase with a novel degradation pattern on highly substituted galactomannans.

    Science.gov (United States)

    von Freiesleben, Pernille; Spodsberg, Nikolaj; Blicher, Thomas Holberg; Anderson, Lars; Jørgensen, Henning; Stålbrand, Henrik; Meyer, Anne S; Krogh, Kristian B R M

    2016-02-01

    The activity and substrate degradation pattern of a novel Aspergillus nidulans GH26 endo-β-mannanase (AnMan26A) was investigated using two galactomannan substrates with varying amounts of galactopyranosyl residues. The AnMan26A was characterized in parallel with the GH26 endomannanase from Podospora anserina (PaMan26A) and three GH5 endomannanases from A. nidulans and Trichoderma reesei (AnMan5A, AnMan5C and TrMan5A). The initial rates and the maximal degree of enzymatically catalyzed conversion of locust bean gum and guar gum galactomannans were determined. The hydrolysis product profile at maximal degree of conversion was determined using DNA sequencer-Assisted Saccharide analysis in High throughput (DASH). This is the first reported use of this method for analyzing galactomannooligosaccharides. AnMan26A and PaMan26A were found to have a novel substrate degradation pattern on the two galactomannan substrates. On the highly substituted guar gum AnMan26A and PaMan26A reached 35-40% as their maximal degree of conversion whereas the three tested GH5 endomannanases only reached 8-10% as their maximal degree of conversion. α-Galactosyl-mannose was identified as the dominant degradation product resulting from AnMan26A and PaMan26A action on guar gum, strongly indicating that these two enzymes can accommodate galactopyranosyl residues in the -1 and in the +1 subsite. The degradation of α-6(4)-6(3)-di-galactosyl-mannopentaose by AnMan26A revealed accommodation of galactopyranosyl residues in the -2, -1 and +1 subsite of the enzyme. Accommodation of galactopyranosyl residues in subsites -2 and +1 has not been observed for other characterized endomannanases to date. Docking analysis of galactomannooligosaccharides in available crystal structures and homology models supported the conclusions drawn from the experimental results. This newly discovered diversity of substrate degradation patterns demonstrates an expanded functionality of fungal endomannanases, than hitherto

  7. Studies of the Production of Fungal Polyketides in Aspergillus nidulans by Using Systems Biology Tools▿ †

    OpenAIRE

    Panagiotou, Gianni; Andersen, Mikael R.; Grotkjaer, Thomas; Regueira, Torsten B.; Nielsen, Jens; Olsson, Lisbeth

    2009-01-01

    Many filamentous fungi produce polyketide molecules with great significance as human pharmaceuticals; these molecules include the cholesterol-lowering compound lovastatin, which was originally isolated from Aspergillus terreus. The chemical diversity and potential uses of these compounds are virtually unlimited, and it is thus of great interest to develop a well-described microbial production platform for polyketides. Using genetic engineering tools available for the model organism Aspergillu...

  8. Quantitative Analysis of the Relative Transcript Levels of ABC Transporter Atr Genes in Aspergillus nidulans by Real-Time Reverse Transcription-PCR Assay

    OpenAIRE

    Pizeta Semighini, Camile; Marins, Mozart; Goldman, Maria Helena S.; Goldman, Gustavo Henrique

    2002-01-01

    The development of assays for quantitative analysis of the relative transcript levels of ABC transporter genes by real-time reverse transcription-PCR (RT-PCR) might provide important information about multidrug resistance in filamentous fungi. Here, we evaluate the potential of real-time RT-PCR to quantify the relative transcript levels of ABC transporter Atr genes from Aspergillus nidulans. The AtrA to AtrD genes showed different and higher levels in the presence of structurally unrelated dr...

  9. Modelling and mutational analysis of Aspergillus nidulans UreA, a member of the subfamily of urea/H+ transporters in fungi and plants

    OpenAIRE

    Sanguinetti, Manuel; Amillis, Sotiris; Pantano, Sergio; Scazzocchio, Claudio; Ramón, Ana

    2014-01-01

    We present the first account of the structure–function relationships of a protein of the subfamily of urea/H+ membrane transporters of fungi and plants, using Aspergillus nidulans UreA as a study model. Based on the crystal structures of the Vibrio parahaemolyticus sodium/galactose symporter (vSGLT) and of the Nucleobase-Cation-Symport-1 benzylhydantoin transporter from Microbacterium liquefaciens (Mhp1), we constructed a three-dimensional model of UreA which, combined with site-directed and ...

  10. Hypomorphic bimA(APC3) alleles cause errors in chromosome metabolism that activate the DNA damage checkpoint blocking cytokinesis in Aspergillus nidulans.

    OpenAIRE

    Wolkow, T D; Mirabito, P.M.; Venkatram, S; Hamer, J. E.

    2000-01-01

    The Aspergillus nidulans sepI(+) gene has been implicated in the coordination of septation with nuclear division and cell growth. We find that the temperature-sensitive (ts) sepI1 mutation represents a novel allele of bimA(APC3), which encodes a conserved component of the anaphase-promoting complex/cyclosome (APC/C). We have characterized the septation, nuclear division, cell-cycle checkpoint defects, and DNA sequence alterations of sepI1 (renamed bimA10) and two other ts lethal bimA(APC3) al...

  11. Evidence that two Pcl-like cyclins control Cdk9 activity during cell differentiation in Aspergillus nidulans asexual development.

    Science.gov (United States)

    Kempf, Claudia; Bathe, Friederike; Fischer, Reinhard

    2013-01-01

    Cyclin-dependent protein kinases (CDKs) are usually involved in cell cycle regulation. However, Cdk9 is an exception and promotes RNA synthesis through phosphorylation of the carboxy-terminal domain (CTD) of the largest subunit of RNA polymerase II (RNAPII). The CTD is comprised of repeating heptapeptides, in which serine residues at positions 2, 5, and 7 are of crucial importance. Ser5 phosphorylation causes transcription initiation and promoter escape. However, RNAPII pauses 20 to 50 bp downstream from the transcription start site, until Cdk9 phosphorylates Ser2. This event relieves the checkpoint and promotes the processivity of elongation. Here we present evidence that in the filamentous fungus Aspergillus nidulans, a Cdk9 homologue, PtkA, serves specific functions in conidiophore development. It was previously shown that PtkA interacts with two cyclins, PclA and the T cyclin PchA. Using yeast two-hybrid screens, we identified a third cyclin, PclB, and a kinase, PipA(Bud32). Both proteins were expressed in hyphae and in conidiophores, but interaction between each protein and PtkA was restricted to the conidiophores. Deletion of pchA caused a severe growth defect, and deletion of pipA was lethal, suggesting basic functions in PtkA-dependent gene transcription. In contrast, deletion of pclB in combination with deletion of pclA essentially caused a block in spore formation. We present evidence that the phosphorylation status of the CTD of RNA polymerase II in the conidiophore changes upon deletion of pclA or pclB. Our results suggest that tissue-specific modulation of Cdk9 activity by PclA and PclB is required for proper differentiation. PMID:23104571

  12. ATP-citrate lyase is required for production of cytosolic acetyl coenzyme A and development in Aspergillus nidulans.

    Science.gov (United States)

    Hynes, Michael J; Murray, Sandra L

    2010-07-01

    Acetyl coenzyme A (CoA) is a central metabolite in carbon and energy metabolism and in the biosynthesis of cellular molecules. A source of cytoplasmic acetyl-CoA is essential for the production of fatty acids and sterols and for protein acetylation, including histone acetylation in the nucleus. In Saccharomyces cerevisiae and Candida albicans acetyl-CoA is produced from acetate by cytoplasmic acetyl-CoA synthetase, while in plants and animals acetyl-CoA is derived from citrate via ATP-citrate lyase. In the filamentous ascomycete Aspergillus nidulans, tandem divergently transcribed genes (aclA and aclB) encode the subunits of ATP-citrate lyase, and we have deleted these genes. Growth is greatly diminished on carbon sources that do not result in cytoplasmic acetyl-CoA, such as glucose and proline, while growth is not affected on carbon sources that result in the production of cytoplasmic acetyl-CoA, such as acetate and ethanol. Addition of acetate restores growth on glucose or proline, and this is dependent on facA, which encodes cytoplasmic acetyl-CoA synthetase, but not on the regulatory gene facB. Transcription of aclA and aclB is repressed by growth on acetate or ethanol. Loss of ATP-citrate lyase results in severe developmental effects, with the production of asexual spores (conidia) being greatly reduced and a complete absence of sexual development. This is in contrast to Sordaria macrospora, in which fruiting body formation is initiated but maturation is defective in an ATP-citrate lyase mutant. Addition of acetate does not repair these defects, indicating a specific requirement for high levels of cytoplasmic acetyl-CoA during differentiation. Complementation in heterokaryons between aclA and aclB deletions for all phenotypes indicates that the tandem gene arrangement is not essential. PMID:20495057

  13. A combined genetic and multi medium approach revels new secondary metabolites in Aspergillus nidulans

    OpenAIRE

    Klejnstrup, Marie Louise; Nielsen, Morten Thrane; Frisvad, Jens Christian; Mortensen, Uffe Hasbro; Larsen, Thomas Ostenfeld

    2011-01-01

    Secondary metabolites are a diverse group of metabolites which serve as important natural sources of drugs for treating diseases. The availability of full genome sequences of several filamentous fungi has revealed a large genetic potential for production of secondary metabolites that are not observed under standard laboratory conditions. Genetic approaches have proven a fruitfull strategy towards the production and identification of these unknown metabolites. Examples include deletion of the ...

  14. The Aspergillus Genome Database, a curated comparative genomics resource for gene, protein and sequence information for the Aspergillus research community

    OpenAIRE

    Arnaud, Martha B.; Chibucos, Marcus C; Costanzo, Maria C.; Crabtree, Jonathan; Inglis, Diane O.; Lotia, Adil; Orvis, Joshua; Shah, Prachi; Skrzypek, Marek S.; Binkley, Gail; Miyasato, Stuart R.; Wortman, Jennifer R.; Sherlock, Gavin

    2009-01-01

    The Aspergillus Genome Database (AspGD) is an online genomics resource for researchers studying the genetics and molecular biology of the Aspergilli. AspGD combines high-quality manual curation of the experimental scientific literature examining the genetics and molecular biology of Aspergilli, cutting-edge comparative genomics approaches to iteratively refine and improve structural gene annotations across multiple Aspergillus species, and web-based research tools for accessing and exploring ...

  15. Quantitative Analysis of the Relative Transcript Levels of ABC Transporter Atr Genes in Aspergillus nidulans by Real-Time Reverse Transcription-PCR Assay

    Science.gov (United States)

    Pizeta Semighini, Camile; Marins, Mozart; Goldman, Maria Helena S.; Goldman, Gustavo Henrique

    2002-01-01

    The development of assays for quantitative analysis of the relative transcript levels of ABC transporter genes by real-time reverse transcription-PCR (RT-PCR) might provide important information about multidrug resistance in filamentous fungi. Here, we evaluate the potential of real-time RT-PCR to quantify the relative transcript levels of ABC transporter Atr genes from Aspergillus nidulans. The AtrA to AtrD genes showed different and higher levels in the presence of structurally unrelated drugs, such as camptothecin, imazalil, itraconazole, hygromycin, and 4-nitroquinoline oxide. We also verified the relative transcript levels of the Atr genes in the A. nidulans imazalil-resistant mutants. These genes displayed a very complex pattern in different ima genetic backgrounds. The imaB mutant has higher basal transcript levels of AtrB and -D than those of the wild-type strain. The levels of these two genes are comparable when the imaB mutant is grown in the presence and absence of imazalil. The imaC, -D, and -H mutants have higher basal levels of AtrA than that of the wild type. The same behavior is observed for the relative transcript levels of AtrB in the imaG mutant background. PMID:11872487

  16. Analysis of the Aspergillus nidulans thaumatin-like cetA gene and evidence for transcriptional repression of pyr4 expression in the cetA-disrupted strain.

    Science.gov (United States)

    Greenstein, Shulamit; Shadkchan, Yona; Jadoun, Jeries; Sharon, Chaim; Markovich, Sarit; Osherov, Nir

    2006-01-01

    The asexual spore or conidium plays a critical role in the life cycle of many filamentous fungi. However, the process of conidial germination remains surprisingly obscure. To better understand this process at the molecular level we characterized the Aspergillus nidulans cetA gene which is uniquely transcribed in conidiating cultures and whose transcript is significantly enriched in mature conidia. CetA is a member of a novel family of fungal genes of unknown function with homology to plant thaumatin-like (PR-5) defense proteins. We demonstrate by Northern analysis that cetA is a glucose-repressible gene. Transcriptional repression is dependent on the presence of protein kinase A. Western analysis indicates that the CETA protein is absent from conidia but is highly expressed during the first 6h of germination and is secreted into the medium. Disruption of the cetA gene seemingly results in delayed germination, slow growth, abnormal hyphal branching, and cell-wall defects. However, further analysis shows that the mutant phenotype is the result of glucose-dependent transcriptional repression of the pyr4 selectable marker used to disrupt the cetA gene. This is the first time that repression of a selectable marker ("position effect") has been reported in A. nidulans, a finding that may well be of significance in the analysis and interpretation of mutant phenotypes in this organism. PMID:16376592

  17. An ortholog of farA of Aspergillus nidulans is implicated in the transcriptional activation of genes involved in fatty acid utilization in the yeast Yarrowia lipolytica

    International Nuclear Information System (INIS)

    Research highlights: → POR1 is a Yarrowia lipolytica ortholog of farA involved in fatty acid response in A. nidulans. → Deletion of POR1 caused growth defects on fatty acids. → Δpor1 strain exhibited defects in the induction of genes involved in fatty acid utilization. -- Abstract: The yeast Yarrowia lipolytica effectively utilizes hydrophobic substrates such as fatty acids and n-alkanes. To identify a gene(s) regulating fatty acid utilization in Y. lipolytica, we first studied homologous genes to OAF1 and PIP2 of Saccharomyces cerevisiae, but their disruption did not change growth on oleic acid at all. We next characterized a Y. lipolytica gene, POR1 (primary oleate regulator 1), an ortholog of farA encoding a transcriptional activator that regulates fatty acid utilization in Aspergillus nidulans. The deletion mutant of POR1 was defective in the growth on various fatty acids, but not on glucose, glycerol, or n-hexadecane. It exhibited slight defect on n-decane. The transcriptional induction of genes involved in β-oxidation and peroxisome proliferation by oleate was distinctly diminished in the Δpor1 strains. These data suggest that POR1 encodes a transcriptional activator widely regulating fatty acid metabolism in Y. lipolytica.

  18. An ortholog of farA of Aspergillus nidulans is implicated in the transcriptional activation of genes involved in fatty acid utilization in the yeast Yarrowia lipolytica

    Energy Technology Data Exchange (ETDEWEB)

    Poopanitpan, Napapol; Kobayashi, Satoshi; Fukuda, Ryouichi; Horiuchi, Hiroyuki [Department of Biotechnology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657 (Japan); Ohta, Akinori, E-mail: aaohta@mail.ecc.u-tokyo.ac.jp [Department of Biotechnology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657 (Japan)

    2010-11-26

    Research highlights: {yields} POR1 is a Yarrowia lipolytica ortholog of farA involved in fatty acid response in A. nidulans. {yields} Deletion of POR1 caused growth defects on fatty acids. {yields} {Delta}por1 strain exhibited defects in the induction of genes involved in fatty acid utilization. -- Abstract: The yeast Yarrowia lipolytica effectively utilizes hydrophobic substrates such as fatty acids and n-alkanes. To identify a gene(s) regulating fatty acid utilization in Y. lipolytica, we first studied homologous genes to OAF1 and PIP2 of Saccharomyces cerevisiae, but their disruption did not change growth on oleic acid at all. We next characterized a Y. lipolytica gene, POR1 (primary oleate regulator 1), an ortholog of farA encoding a transcriptional activator that regulates fatty acid utilization in Aspergillus nidulans. The deletion mutant of POR1 was defective in the growth on various fatty acids, but not on glucose, glycerol, or n-hexadecane. It exhibited slight defect on n-decane. The transcriptional induction of genes involved in {beta}-oxidation and peroxisome proliferation by oleate was distinctly diminished in the {Delta}por1 strains. These data suggest that POR1 encodes a transcriptional activator widely regulating fatty acid metabolism in Y. lipolytica.

  19. The mutagenic effect of near ultraviolet light on the nvs strains of Aspergillus nidulans in the presence of 8-metoxypsoralen or angelicin

    International Nuclear Information System (INIS)

    The mutual mutagenic effect of long-wave ultraviolet radiation (EUV) with angelicin which forms monoadducts in DNA and 8-metoxypsoralen (8 MOP) which forms monoadducts and joints, on conidia of uvs- and uvs+ strains of Aspergillus nidulans, is studied. The two types of interaction are shown to induce mutations intensively. Mutation induction with angelicin shows the role of psoralen pyrimidine monoadducts in mutagenesis. The technique of fractionated EUV radiation and studying the effect of monoadduct repair effectiveness on mutation output permits to prove that interthread DNA joints induced by 8-MOP+EUV are also highly mutagenous. The products of UVS/2, 20b, 26 genes which take part in the excision of DNA damages do not take part in the formation of mutations induced in aspergil by furocoumarine + EUV. The products of uvs 19, 20a genes which take part in the postreplicative DNA reduction are neccessary for the repair of premutation damages induced by furocoumarine + EUV

  20. X-ray induced degradation of DNA in Aspergillus nidulans cells comparative analysis of UV- and X-ray induced DNA degradation

    International Nuclear Information System (INIS)

    Irradiating cells of Aspergillus nidulans of the wild type in the logarythmical growth phase with X-rays leads to a certain retention in DNA synthesis. This period is characterized by an insignificant fermentative DNA degradation connected with a process of its repair. There is no direct dependence between the radiation dose and the level of DNA degradation. The investigation of X-ray induced DNA degradation in a number of UVS-mutants permits to show the existence of two branches of DNA degradation - dependent and independent of the exogenic energy source. The dependence of DNA degradation on albumen synthesis prior to irradiation and after it, is demonstrated. It is supposed that the level of X-ray induced DNA degradation is determined by two albumen systems, one of which initiates degradation and the other terminates it. The comparative analysis of UV and X-ray induced DNA degradation is carried out

  1. A short-term test adapted to detect the genotoxic effects of environmental volatile pollutants (benzene fumes) using the filamentous fungus Aspergillus nidulans.

    Science.gov (United States)

    Domingues Zucchi, Tiago; Domingues Zucchi, Fernando; Poli, Paola; Soares de Melo, Itamar; Zucchi, Tania M A D

    2005-06-01

    With the recent focus on environmental problems, increasing awareness of the harmful effects of industrial and agricultural pollution has created a demand for progressively more sophisticated pollutant and toxicity detection methods. Using Aspergillus nidulans strains this work presents a new short term-test that, most importantly, enables the rapid and inexpensive detection of volatile pollutants that induce genotoxic/carcinogenic effects in animals. The main aim is to contribute to environmental health protection, and special attention is directed to monitoring the hazard posed by benzene (as a carcinogenic agent model) mainly because its ubiquitous presence often leads to severe noxious effects in humans among whom increased rates of human leukemia have been reported. To evaluate even the submutagenic effects of benzene fumes, two Aspergillus nidulans diploid strains, heterozygous for several auxotrophic mutations, were used. The DNA lesions produced stimulate mitotic recombination and homozygotization of auxotrophic recessive mutations. Conidial exposure to a saturated atmosphere of benzene fumes for 20 s was enough to increase the mitotic recombination frequencies significantly. Genetic analyses of treated diploids evidenced alterations related to mitotic recombination frequencies, gene expression, and allelic segregation rates. Altogether they reflect the potential of benzene to induce alterations in the fungal DNA, and albeit indirectly, they also respond for the genotoxic/carcinogenic harmful side effects widely connected to benzene. This is the first description of a sensitive, rapid and inexpensive test able to detect the submutagenic dose effects of volatile environmental compounds. In addition, despite concentrating on benzene the same test can be applied to many other pollutants, volatile or not. Additionally, the test can also be used to detect the antigenotoxic properties of foods and drugs. PMID:15931421

  2. The induction of mutations to 2-thioxanthine resistance in inhibitor depleted conidia of Aspergillus nidulans by gamma-radiation in the presence of oxygen or nitrogen

    International Nuclear Information System (INIS)

    A strain of Aspergillus nidulans has been used to study the inactivating and mutagenic effect of 60Coγ-rays in the presence of oxygen or nitrogen. Mutation was studied by the 2-thioxanthine system which selectively detects forward mutation at a number of gene loci (at least 16). Mutants resistant to conidial pigmentation effects of 2-thioxanthine can be divided into four main classes (2TxR, hx, uaY and cnx) and three of these classes (hx, uaY and cnx) can be further characterized at the gene level. The results demonstrate the existence of a marked differential forward mutational response of gene loci in Aspergillus conidia which is dependent upon whether γ-irradiation in aqueous suspension was carried out in the presence of oxygen or nitrogen: this effect is independent of the dose of radiation exposure. The specificity for mutation is altered by the presence of the self-inhibitor of germination for the anoxic treatment but not the oxic irradiation. The implication of different oxygen enhancement ratios for mutation induction in different classes or genes for the mechanism and type of damage induced by the two radiation conditions are discussed

  3. Mutation in the bimD gene of Aspergillus nidulans confers a conditional mitotic block and sensitivity to DNA damaging agents

    International Nuclear Information System (INIS)

    Mutation in the bimD gene of Aspergillus nidulans results in a mitotic block in anaphase characterized by a defective mitosis. Mutation in bimD also confers, at temperatures permissive for the mitotic arrest phenotype, an increased sensitivity to DNA damaging agents, including methyl methanesulfonate and ultraviolet light. In order to better understand the relationship between DNA damage and mitotic progression, the authors cloned the bimD gene from Aspergillus. A cosmid containing the bimD gene was identified among pools of cosmids by cotransformation with the nutritional selective pyrG gene of a strain carrying the recessive, temperature-sensitive lethal bimD6 mutation. The bimD gene encodes a predicted polypeptide of 166,000 daltons in mass and contains amino acid sequence motifs similar to those found in some DNA-binding transcription factors. These sequences include a basic domain followed by a leucine zipper, which together are called a bZIP motif, and a carboxyl-terminal domain enriched in acidic amino acids. Overexpression of the wild-type bimD protein resulted in an arrest of the nuclear division cycle that was reversible and determined to be in either the G1 or S phase of the cell cycle. The data suggest that bimD may play an essential regulatory role relating to DNA metabolism which is required for a successful mitosis. 7l refs., 7 figs., 1 tab

  4. Genome-wide analysis of the Zn(II)₂Cys₆ zinc cluster-encoding gene family in Aspergillus flavus.

    Science.gov (United States)

    Chang, Perng-Kuang; Ehrlich, Kenneth C

    2013-05-01

    Proteins with a Zn(II)₂Cys₆ domain, Cys-X₂-Cys-X₆-Cys-X₅₋₁₂-Cys-X₂-Cys-X₆₋₉-Cys (hereafter, referred to as the C6 domain), form a subclass of zinc finger proteins found exclusively in fungi and yeast. Genome sequence databases of Saccharomyces cerevisiae and Candida albicans have provided an overview of this family of genes. Annotation of this gene family in most fungal genomes is still far from perfect and refined bioinformatic algorithms are urgently needed. Aspergillus flavus is a saprophytic soil fungus that can produce the carcinogenic aflatoxin. It is the second leading causative agent of invasive aspergillosis. The 37-Mb genome of A. flavus is predicted to encode 12,000 proteins. Two and a half percent of the total proteins are estimated to contain the C6 domain, more than twofold greater than those estimated for yeast, which is about 1 %. The variability in the spacing between cysteines, C₃-C₄ and C₅-C₆, in the zinc cluster enables classification of the domains into distinct subgroups, which are also well conserved in Aspergillus nidulans. Sixty-six percent (202/306) of the A. flavus C6 proteins contain a specific transcription factor domain, and 7 % contain a domain of unknown function, DUF3468. Two A. nidulans C6 proteins containing the DUF3468 are involved in asexual conidiation and another two in sexual differentiation. In the anamorphic A. flavus, a homolog of the latter lacks the C6 domain. A. flavus being heterothallic and reproducing mainly through conidiation appears to have lost some components involved in homothallic sexual development. Of the 55 predicted gene clusters thought to be involved in production of secondary metabolites, only about half have a C6-encoding gene in or near the gene clusters. The features revealed by the A. flavus C6 proteins likely are common for other ascomycete fungi. PMID:23563886

  5. Aspergillus nidulans Synthesize Insect Juvenile Hormones upon Expression of a Heterologous Regulatory Protein and in Response to Grazing by Drosophila melanogaster Larvae

    DEFF Research Database (Denmark)

    Nielsen, Morten Thrane; Klejnstrup, Marie Louise; Rohlfs, Marko;

    2013-01-01

    Secondary metabolites are known to serve a wide range of specialized functions including communication, developmental control and defense. Genome sequencing of several fungal model species revealed that the majority of predicted secondary metabolite related genes are silent in laboratory strains,...... larvae induced synthesis of juvenile hormone in A. nidulans indicating a possible role of juvenile hormone biosynthesis in affecting fungal-insect antagonisms....

  6. Arabidopsis and Brachypodium distachyon transgenic plants expressing Aspergillus nidulans acetylesterases have decreased degree of polysaccharide acetylation and increased resistance to pathogens.

    Science.gov (United States)

    Pogorelko, Gennady; Lionetti, Vincenzo; Fursova, Oksana; Sundaram, Raman M; Qi, Mingsheng; Whitham, Steven A; Bogdanove, Adam J; Bellincampi, Daniela; Zabotina, Olga A

    2013-05-01

    The plant cell wall has many significant structural and physiological roles, but the contributions of the various components to these roles remain unclear. Modification of cell wall properties can affect key agronomic traits such as disease resistance and plant growth. The plant cell wall is composed of diverse polysaccharides often decorated with methyl, acetyl, and feruloyl groups linked to the sugar subunits. In this study, we examined the effect of perturbing cell wall acetylation by making transgenic Arabidopsis (Arabidopsis thaliana) and Brachypodium (Brachypodium distachyon) plants expressing hemicellulose- and pectin-specific fungal acetylesterases. All transgenic plants carried highly expressed active Aspergillus nidulans acetylesterases localized to the apoplast and had significant reduction of cell wall acetylation compared with wild-type plants. Partial deacetylation of polysaccharides caused compensatory up-regulation of three known acetyltransferases and increased polysaccharide accessibility to glycosyl hydrolases. Transgenic plants showed increased resistance to the fungal pathogens Botrytis cinerea and Bipolaris sorokiniana but not to the bacterial pathogens Pseudomonas syringae and Xanthomonas oryzae. These results demonstrate a role, in both monocot and dicot plants, of hemicellulose and pectin acetylation in plant defense against fungal pathogens. PMID:23463782

  7. GmcA is a putative glucose-methanol-choline oxidoreductase required for the induction of asexual development in Aspergillus nidulans.

    Directory of Open Access Journals (Sweden)

    Oier Etxebeste

    Full Text Available Aspergillus nidulans asexual differentiation is induced by Upstream Developmental Activators (UDAs that include the bZIP-type Transcription Factor (TF FlbB. A 2D-PAGE/MS-MS-coupled screen for proteins differentially expressed in the presence and absence of FlbB identified 18 candidates. Most candidates belong to GO term classes involved in osmotic and/or oxidative stress response. Among these, we focused on GmcA, a putative glucose-methanol-choline oxidoreductase which is upregulated in a ΔflbB background. GmcA is not required for growth since no differences were detected in the radial extension upon deletion of gmcA. However, its activity is required to induce conidiation under specific culture conditions. A ΔgmcA strain conidiates profusely under acid conditions but displays a characteristic fluffy aconidial phenotype in alkaline medium. The absence of asexual development in a ΔgmcA strain can be suppressed, on one hand, using high concentrations of non-fermentable carbon sources like glycerol, and on the other hand, when the cMyb-type UDA TF flbD is overexpressed. Overall, the results obtained in this work support a role for GmcA at early stages of conidiophore initiation.

  8. GmcA is a putative glucose-methanol-choline oxidoreductase required for the induction of asexual development in Aspergillus nidulans.

    Science.gov (United States)

    Etxebeste, Oier; Herrero-García, Erika; Cortese, Marc S; Garzia, Aitor; Oiartzabal-Arano, Elixabet; de los Ríos, Vivian; Ugalde, Unai; Espeso, Eduardo A

    2012-01-01

    Aspergillus nidulans asexual differentiation is induced by Upstream Developmental Activators (UDAs) that include the bZIP-type Transcription Factor (TF) FlbB. A 2D-PAGE/MS-MS-coupled screen for proteins differentially expressed in the presence and absence of FlbB identified 18 candidates. Most candidates belong to GO term classes involved in osmotic and/or oxidative stress response. Among these, we focused on GmcA, a putative glucose-methanol-choline oxidoreductase which is upregulated in a ΔflbB background. GmcA is not required for growth since no differences were detected in the radial extension upon deletion of gmcA. However, its activity is required to induce conidiation under specific culture conditions. A ΔgmcA strain conidiates profusely under acid conditions but displays a characteristic fluffy aconidial phenotype in alkaline medium. The absence of asexual development in a ΔgmcA strain can be suppressed, on one hand, using high concentrations of non-fermentable carbon sources like glycerol, and on the other hand, when the cMyb-type UDA TF flbD is overexpressed. Overall, the results obtained in this work support a role for GmcA at early stages of conidiophore initiation. PMID:22792266

  9. Mutagenicity of monoadducts and cross-links induced in Aspergillus nidulans by 8-methoxypsoralen plus 365 nm radiation

    International Nuclear Information System (INIS)

    8-Methoxypsoralen plus 365 nm radiation induces mutation at the methionine supressor loci of Aspergillus inhibitor-deficient conidia at low doses of near-UV radiation with one-hit kinetics and at higher near-UV radiation doses with two-hit kinetics. These results and others suggest that both monoadducts and cross-links, formed by 8-methoxypsoralen and DNA upon exposure to UV radiation, are capable of inducing mutation. Evidence is also presented that induced furocoumarin cross-links are responsible for the inactivation of the Aspergillus conidium. (author)

  10. Utilização de linhagens diplóides uvsH//uvsH de Aspergillus nidulans (Ascomycetes para a avaliação do potencial recombinagênico de agentes químicos e físicos uvsH//uvsH diploid strain favors an efficient method to evaluate the recombinagenic effect of chemical and physical agents in Aspergillus nidulans (Ascomycetes

    Directory of Open Access Journals (Sweden)

    Francielle Baptista

    2001-05-01

    Full Text Available O ascomiceto Aspergillus nidulans apresenta-se como um excelente sistema para o estudo da recombinação somática, por passar grande parte de seu ciclo celular em G2 e por apresentar mutações uvs que promovem aumento das freqüências normais de recombinação mitótica (uvsF e uvsH. O presente trabalho teve como objetivo obter uma nova linhagem diplóide de A. nidulans, com características apropriadas para estudos da recombinagênese, tais como: hetererozigose para marcadores nutricionais e de coloração de conidios e homozigose para a mutação uvsH. A maior sensibilidade do diplóide uvsH//uvsH no monitoramento de eventos de recombinação mitótica foi demonstrada através dos mais altos índices de recombinação mitótica espontânea por ele apresentados, em comparação com o diplóide uvsH+//uvsH +. A nova linhagem apresenta-se como uma ferramenta versátil, podendo ser utilizada em diferentes estudos relacionados à recombinação mitótica em A. nidulansAscomycete Aspergillus nidulans is an excellent system for mitotic crossing-over studies. This is due to the fact that much of its cell cycle is passed in G2 and presents uvs mutations that increase frequencies of normal mitotic recombinations (uvsF and uvsH. The aim of this research was to obtain a new diploid strain of A. nidulans with proper characteristics for recombinagenesis investigations, or rather, heterozygous for nutritional markers and conidia coloration and homozygous for uvsH mutation. Higher sensitivity of diploid uvsH//uvsH in the monitoring of mitotic recombination events was shown by higher indexes of the diploid’s spontaneous mitotic recombination when compared with diploid uvsH+//uvsH +. New strain is a versatile tool that may be used in different studies on mitotic recombination in A. nidulans

  11. The TamA protein fused to a DNA-binding domain can recruit AreA, the major nitrogen regulatory protein, to activate gene expression in Aspergillus nidulans.

    OpenAIRE

    Small, A J; Hynes, M J; Davis, M A

    1999-01-01

    The areA gene of Aspergillus nidulans encodes a GATA zinc finger transcription factor that activates the expression of a large number of genes subject to nitrogen metabolite repression. The amount and activity of the AreA protein under different nitrogen conditions is modulated by transcriptional, post-transcriptional, and post-translational controls. One of these controls of AreA activity has been proposed to involve the NmrA protein interacting with the DNA-binding domain and the extreme C ...

  12. Sexual structures in Aspergillus: morphology, importance and genomics.

    Science.gov (United States)

    Geiser, David M

    2009-01-01

    The genus Aspergillus comprises a few hundred species sharing a common asexual spore forming structure, the aspergillum. Approximately one-third of these species also produce a sexual stage, all but five of which are known to be homothallic. Sexual stages associated with Aspergillus fall into approximately ten different genera, reflecting a tremendous degree of phylogenetic and biological diversity. Sexual stages in Aspergillus are plectomycetous, typical for the order in which it resides, the Eurotiales. Theoretically, a homothallic Aspergillus species can produce both asexual conidia and sexual ascospores in both clonal and recombinant fashion, although the actual significance of these potential modes of reproduction is unclear. Aspergillus species with known sexual stages tend to be minor players in infections of humans, perhaps because of their tendency to produce fewer asexual spores compared to their non-teleomorphic congeners. The discovery of population genetic and genomic evidence for sex in species with no known sexual stage indicates that no assumptions can be made about the clonal versus recombinant life histories of a species based on its known mitotic and/or meiotic reproductive modes. PMID:18608901

  13. Calcineurin and Calcium Channel CchA Coordinate the Salt Stress Response by Regulating Cytoplasmic Ca2+ Homeostasis in Aspergillus nidulans.

    Science.gov (United States)

    Wang, Sha; Liu, Xiao; Qian, Hui; Zhang, Shizhu; Lu, Ling

    2016-06-01

    The eukaryotic calcium/calmodulin-dependent protein phosphatase calcineurin is crucial for the environmental adaption of fungi. However, the mechanism of coordinate regulation of the response to salt stress by calcineurin and the high-affinity calcium channel CchA in fungi is not well understood. Here we show that the deletion of cchA suppresses the hyphal growth defects caused by the loss of calcineurin under salt stress in Aspergillus nidulans Additionally, the hypersensitivity of the ΔcnaA strain to extracellular calcium and cell-wall-damaging agents can be suppressed by cchA deletion. Using the calcium-sensitive photoprotein aequorin to monitor the cytoplasmic Ca(2+) concentration ([Ca(2+)]c) in living cells, we found that calcineurin negatively regulates CchA on calcium uptake in response to external calcium in normally cultured cells. However, in salt-stress-pretreated cells, loss of either cnaA or cchA significantly decreased the [Ca(2+)]c, but a deficiency in both cnaA and cchA switches the [Ca(2+)]c to the reference strain level, indicating that calcineurin and CchA synergistically coordinate calcium influx under salt stress. Moreover, real-time PCR results showed that the dysfunction of cchA in the ΔcnaA strain dramatically restored the expression of enaA (a major determinant for sodium detoxification), which was abolished in the ΔcnaA strain under salt stress. These results suggest that double deficiencies of cnaA and cchA could bypass the requirement of calcineurin to induce enaA expression under salt stress. Finally, YvcA, a member of the transient receptor potential channel (TRPC) protein family of vacuolar Ca(2+) channels, was proven to compensate for calcineurin-CchA in fungal salt stress adaption.IMPORTANCE The feedback inhibition relationship between calcineurin and the calcium channel Cch1/Mid1 has been well recognized from yeast. Interestingly, our previous study (S. Wang et al., PLoS One 7:e46564, 2012, http://dx.doi.org/10.1371/journal

  14. Aspergillus nidulans transcription factor AtfA interacts with the MAPK SakA to regulate general stress responses, development and spore functions.

    Science.gov (United States)

    Lara-Rojas, Fernando; Sánchez, Olivia; Kawasaki, Laura; Aguirre, Jesús

    2011-04-01

    Fungi utilize a phosphorelay system coupled to a MAP kinase module for sensing and processing environmental signals. In Aspergillus nidulans, response regulator SskA transmits osmotic and oxidative stress signals to the stress MAPK (SAPK) SakA. Using a genetic approach together with GFP tagging and molecular bifluorescence we show that SakA and ATF/CREB transcription factor AtfA define a general stress-signalling pathway that plays differential roles in oxidative stress responses during growth and development. AtfA is permanently localized in the nucleus, while SakA accumulates in the nucleus in response to oxidative or osmotic stress signals or during normal spore development, where it physically interacts with AtfA. AtfA is required for expression of several genes, the conidial accumulation of SakA and the viability of conidia. Furthermore, SakA is active (phosphorylated) in asexual spores, remaining phosphorylated in dormant conidia and becoming dephosphorylated during germination. SakA phosphorylation in spores depends on certain (SskA) but not other (SrrA and NikA) components of the phosphorelay system. Constitutive phosphorylation of SakA induced by the fungicide fludioxonil prevents both, germ tube formation and nuclear division. Similarly, Neurospora crassa SakA orthologue OS-2 is phosphorylated in intact conidia and gets dephosphorylated during germination. We propose that SakA-AtfA interaction regulates gene expression during stress and conidiophore development and that SAPK phosphorylation is a conserved mechanism to regulate transitions between non-growing (spore) and growing (mycelia) states. PMID:21320182

  15. Genome-scale analysis of the high-efficient protein secretion system of Aspergillus oryzae

    DEFF Research Database (Denmark)

    Liu, Lifang; Feizi, Amir; Osterlund, Tobias; Hjort, Carsten; Nielsen, Jens

    2014-01-01

    Background: The koji mold, Aspergillus oryzae is widely used for the production of industrial enzymes due to its particularly high protein secretion capacity and ability to perform post-translational modifications. However, systemic analysis of its secretion system is lacking, generally due to the...... related fungal species such as Aspergillus nidulans and Aspergillus niger. To evaluate the defined component list, we performed transcriptome analysis on three a-amylase over-producing strains with varying levels of secretion capacities. Specifically, secretory components involved in the ER...... overproducing amylase. Conclusion: In combination with the transcriptome data, the most complete secretory component list and the putative secretome, we improved the systemic understanding of the secretory machinery of A. oryzae in response to high levels of protein secretion. The roles of many newly predicted...

  16. Characterization of oxylipins and dioxygenase genes in the asexual fungus Aspergillus niger

    OpenAIRE

    Kalkhove Stefanie IC; de Vries Ronald P; Wadman Mayken W; Veldink Gerrit A; Vliegenthart Johannes FG

    2009-01-01

    Abstract Background Aspergillus niger is an ascomycetous fungus that is known to reproduce through asexual spores, only. Interestingly, recent genome analysis of A. niger has revealed the presence of a full complement of functional genes related to sexual reproduction 1. An example of such genes are the dioxygenase genes which in Aspergillus nidulans, have been shown to be connected to oxylipin production and regulation of both sexual and asexual sporulation 234. Nevertheless, the presence of...

  17. Development of a Candida glabrata dominant nutritional transformation marker utilizing the Aspergillus nidulans acetamidase gene (amdS).

    Science.gov (United States)

    Fu, Jianmin; Blaylock, Morganne; Wickes, Cameron F; Welte, William; Mehrtash, Adrian; Wiederhold, Nathan; Wickes, Brian L

    2016-05-01

    The gene encodingAspergillus nidulansacetamidase (amdS) was placed under control ofCandida albicans ACT1promoter and terminator sequences and then cloned into a plasmid containingC. glabrata ARS10,CEN8orARS10+CEN8sequences. All plasmids transformedC. glabratawild-type cells to acetamide+, with theARS-only containing plasmid transforming cells at the highest frequencies (>1.0 × 10(4)transformants μg(-1)). Plasmids were rapidly lost under non-selective conditions with the frequency dependent on chromosomal element, thus recycling the acetamide- phenotype. TheamdSplasmid was used to transform a set of clinical isolates resistant to a variety of antifungal drugs. All strains were successfully transformed to the acetamide+ phenotype at high frequency, confirming that this plasmid construct could be used as a simple dominant marker on virtually any strain. Gap repair experiments demonstrated that just as inSaccharomyces cerevisiae, gap repair functions efficiently inC. glabrata, suggesting thatC. glabratahas numerous similarities toS. cerevisiaewith regard to ease of molecular manipulation. TheamdSsystem is inexpensive and efficient, and combined with existingC. glabrataplasmid elements, confers a high transformation frequency forC. glabratawith a phenotype that can be easily recycled. PMID:26975388

  18. An efficient arabinoxylan-debranching α-L-arabinofuranosidase of family GH62 from Aspergillus nidulans contains a secondary carbohydrate binding site.

    Science.gov (United States)

    Wilkens, Casper; Andersen, Susan; Petersen, Bent O; Li, An; Busse-Wicher, Marta; Birch, Johnny; Cockburn, Darrell; Nakai, Hiroyuki; Christensen, Hans E M; Kragelund, Birthe B; Dupree, Paul; McCleary, Barry; Hindsgaul, Ole; Hachem, Maher Abou; Svensson, Birte

    2016-07-01

    An α-L-arabinofuranosidase of GH62 from Aspergillus nidulans FGSC A4 (AnAbf62A-m2,3) has an unusually high activity towards wheat arabinoxylan (WAX) (67 U/mg; k cat = 178/s, K m = 4.90 mg/ml) and arabinoxylooligosaccharides (AXOS) with degrees of polymerisation (DP) 3-5 (37-80 U/mg), but about 50 times lower activity for sugar beet arabinan and 4-nitrophenyl-α-L-arabinofuranoside. α-1,2- and α-1,3-linked arabinofuranoses are released from monosubstituted, but not from disubstituted, xylose in WAX and different AXOS as demonstrated by NMR and polysaccharide analysis by carbohydrate gel electrophoresis (PACE). Mutants of the predicted general acid (Glu(188)) and base (Asp(28)) catalysts, and the general acid pK a modulator (Asp(136)) lost 1700-, 165- and 130-fold activities for WAX. WAX, oat spelt xylan, birchwood xylan and barley β-glucan retarded migration of AnAbf62A-m2,3 in affinity electrophoresis (AE) although the latter two are neither substrates nor inhibitors. Trp(23) and Tyr(44), situated about 30 Å from the catalytic site as seen in an AnAbf62A-m2,3 homology model generated using Streptomyces thermoviolaceus SthAbf62A as template, participate in carbohydrate binding. Compared to wild-type, W23A and W23A/Y44A mutants are less retarded in AE, maintain about 70 % activity towards WAX with K i of WAX substrate inhibition increasing 4-7-folds, but lost 77-96 % activity for the AXOS. The Y44A single mutant had less effect, suggesting Trp(23) is a key determinant. AnAbf62A-m2,3 seems to apply different polysaccharide-dependent binding modes, and Trp(23) and Tyr(44) belong to a putative surface binding site which is situated at a distance of the active site and has to be occupied to achieve full activity. PMID:26946172

  19. Response regulators SrrA and SskA are central components of a phosphorelay system involved in stress signal transduction and asexual sporulation in Aspergillus nidulans.

    Science.gov (United States)

    Vargas-Pérez, Itzel; Sánchez, Olivia; Kawasaki, Laura; Georgellis, Dimitris; Aguirre, Jesús

    2007-09-01

    Among eukaryotes, only slime molds, fungi, and plants contain signal transduction phosphorelay systems. In filamentous fungi, multiple sensor kinases appear to use a single histidine-containing phosphotransfer (HPt) protein to relay signals to two response regulators (RR). In Aspergillus nidulans, the RR SskA mediates activation of the mitogen-activated protein kinase SakA in response to osmotic and oxidative stress, whereas the functions of the RR SrrA were unknown. We used a genetic approach to characterize the srrA gene as a new member of the skn7/prr1 family and to analyze the roles of SrrA in the phosphorelay system composed of the RR SskA, the HPt protein YpdA, and the sensor kinase NikA. While mutants lacking the HPt protein YpdA are unviable, mutants lacking SskA (DeltasskA), SrrA (DeltasrrA), or both RR (DeltasrrA DeltasskA) are viable and differentially affected in osmotic and oxidative stress responses. Both RR are involved in osmostress resistance, but DeltasskA mutants are more sensitive to this stress, and only SrrA is required for H(2)O(2) resistance and H(2)O(2)-mediated induction of catalase CatB. In contrast, both RR are individually required for fungicide sensitivity and calcofluor resistance and for normal sporulation and conidiospore viability. The DeltasrrA and DeltasskA sporulation defects appear to be related to decreased mRNA levels of the key sporulation gene brlA. In contrast, conidiospore viability defects do not correlate with the activity of the spore-specific catalase CatA. Our results support a model in which NikA acts upstream of SrrA and SskA to transmit fungicide signals and to regulate asexual sporulation and conidiospore viability. In contrast, NikA appears dispensable for osmotic and oxidative stress signaling. These results highlight important differences in stress signal transmission among fungi and define a phosphorelay system involved in oxidative and osmotic stress, cell wall maintenance, fungicide sensitivity, asexual

  20. The complete mitochondrial genome sequence of Aspergillus flavus.

    Science.gov (United States)

    Yan, Zhengsong; Chen, Dan; Shen, Yiping; Ye, Baodong

    2016-07-01

    Aspergillus flavus is a haploid filamentous fungus that is common in the environment and has been implicated in human infections. The complete mitochondrial genome of A. flavus has been determined by high-throughput sequencing technology in this work. Our study revealed that the mitochondrial genome of A. flavus is 31,602 bp long, with an A + T content of 74.83%, which consists of a usual set of mitochondrial proteins and RNA genes, including large and small ribosomal RNAs, 15 proteins, and 20 tRNA genes and contains two introns. Notably, it also contains two hypothetical proteins without obvious homology to any known proteins. All structural genes are located on one strand and are apparently transcribed in one direction. Codon usage analysis indicated that all protein coding genes employ the standard fungal mitochondrial start and stop codons; and the nucleotide bias toward AT was also reflected in the codon usage. The complete mitochondrial genomes of A. flavus would be useful for future investigation of the genetic, evolution, and clinical identification of Aspergillus species. PMID:25922962

  1. A p53-like transcription factor similar to Ndt80 controls the response to nutrient stress in the filamentous fungus, Aspergillus nidulans [v1; ref status: indexed, http://f1000r.es/y2

    Directory of Open Access Journals (Sweden)

    Margaret E Katz

    2013-03-01

    Full Text Available The Aspergillus nidulans xprG gene encodes a putative transcriptional activator that is a member of the Ndt80 family in the p53-like superfamily of proteins. Previous studies have shown that XprG controls the production of extracellular proteases in response to starvation. We undertook transcriptional profiling to investigate whether XprG has a wider role as a global regulator of the carbon nutrient stress response. Our microarray data showed that the expression of a large number of genes, including genes involved in secondary metabolism, development, high-affinity glucose uptake and autolysis, were altered in an xprGΔ null mutant. Many of these genes are known to be regulated in response to carbon starvation. We confirmed that sterigmatocystin and penicillin production is reduced in xprG- mutants. The loss of fungal mass and secretion of pigments that accompanies fungal autolysis in response to nutrient depletion was accelerated in an xprG1 gain-of-function mutant and decreased or absent in an xprG- mutant. The results support the hypothesis that XprG plays a major role in the response to carbon limitation and that nutrient sensing may represent one of the ancestral roles for the p53-like superfamily. Disruption of the AN6015 gene, which encodes a second Ndt80-like protein, showed that it is required for sexual reproduction in A. nidulans.

  2. An Aspergillus nidulans GH26 endo-β-mannanase with a novel degradation pattern on highly substituted galactomannans

    DEFF Research Database (Denmark)

    von Freiesleben, Pernille; Spodsberg, Nikolaj; Holberg Blicher, Thomas; Anderson, Lars; Jørgensen, Henning; Stålbrand, Henrik; Meyer, Anne S.; Krogh, Kristian B. R. M.

    2016-01-01

    Podospora anserina (PaMan26A) and three GH5 endomannanases from A. nidulans and Trichoderma reesei (AnMan5A, AnMan5C and TrMan5A). The initial rates and the maximal degree of enzymatically catalyzed conversion of locust bean gum and guar gum galactomannans were determined. The hydrolysis product profile at...

  3. Nitrogen Metabolism and Growth Enhancement in Tomato Plants Challenged with Trichoderma harzianum Expressing the Aspergillus nidulans Acetamidase amdS Gene

    Science.gov (United States)

    Domínguez, Sara; Rubio, M. Belén; Cardoza, Rosa E.; Gutiérrez, Santiago; Nicolás, Carlos; Bettiol, Wagner; Hermosa, Rosa; Monte, Enrique

    2016-01-01

    Trichoderma is a fungal genus that includes species that are currently being used as biological control agents and/or as biofertilizers. In addition to the direct application of Trichoderma spp. as biocontrol agents in plant protection, recent studies have focused on the beneficial responses exerted on plants, stimulating the growth, activating the defenses, and/or improving nutrient uptake. The amdS gene, encoding an acetamidase of Aspergillus, has been used as a selectable marker for the transformation of filamentous fungi, including Trichoderma spp., but the physiological effects of the introduction of this gene into the genome of these microorganisms still remains unexplored. No evidence of amdS orthologous genes has been detected within the Trichoderma spp. genomes and the amdS heterologous expression in Trichoderma harzianum T34 did not affect the growth of this fungus in media lacking acetamide. However, it did confer the ability for the fungus to use this amide as a nitrogen source. Although a similar antagonistic behavior was observed for T34 and amdS transformants in dual cultures against Rhizoctonia solani, Botrytis cinerea, and Fusarium oxysporum, a significantly higher antifungal activity was detected in amdS transformants against F. oxysporum, compared to that of T34, in membrane assays on media lacking acetamide. In Trichoderma-tomato interaction assays, amdS transformants were able to promote plant growth to a greater extent than the wild-type T34, although compared with this strain the transformants showed similar capability to colonize tomato roots. Gene expression patterns from aerial parts of 3-week-old tomato plants treated with T34 and the amdS transformants have also been investigated using GeneChip Tomato Genome Arrays. The downregulation of defense genes and the upregulation of carbon and nitrogen metabolism genes observed in the microarrays were accompanied by (i) enhanced growth, (ii) increased carbon and nitrogen levels, and (iii) a

  4. New resources for functional analysis of omics data for the genus Aspergillus

    Directory of Open Access Journals (Sweden)

    Meyer Vera

    2011-10-01

    Full Text Available Abstract Background Detailed and comprehensive genome annotation can be considered a prerequisite for effective analysis and interpretation of omics data. As such, Gene Ontology (GO annotation has become a well accepted framework for functional annotation. The genus Aspergillus comprises fungal species that are important model organisms, plant and human pathogens as well as industrial workhorses. However, GO annotation based on both computational predictions and extended manual curation has so far only been available for one of its species, namely A. nidulans. Results Based on protein homology, we mapped 97% of the 3,498 GO annotated A. nidulans genes to at least one of seven other Aspergillus species: A. niger, A. fumigatus, A. flavus, A. clavatus, A. terreus, A. oryzae and Neosartorya fischeri. GO annotation files compatible with diverse publicly available tools have been generated and deposited online. To further improve their accessibility, we developed a web application for GO enrichment analysis named FetGOat and integrated GO annotations for all Aspergillus species with public genome sequences. Both the annotation files and the web application FetGOat are accessible via the Broad Institute's website (http://www.broadinstitute.org/fetgoat/index.html. To demonstrate the value of those new resources for functional analysis of omics data for the genus Aspergillus, we performed two case studies analyzing microarray data recently published for A. nidulans, A. niger and A. oryzae. Conclusions We mapped A. nidulans GO annotation to seven other Aspergilli. By depositing the newly mapped GO annotation online as well as integrating it into the web tool FetGOat, we provide new, valuable and easily accessible resources for omics data analysis and interpretation for the genus Aspergillus. Furthermore, we have given a general example of how a well annotated genome can help improving GO annotation of related species to subsequently facilitate the

  5. Aspergillus and Penicillium in the Post-genomic Era

    DEFF Research Database (Denmark)

    and a whole genus genome sequencing project in progress for Aspergillus. This book highlights some of the changes in the studies into these fungi, since the availability of genome sequences. The contributions vary from insights in the taxonomy of these genera, use of genomics for forward genetics and......Genome sequencing has affected studies into the biology of all classes of organisms and this is certainly true for filamentous fungi. The level with which biological systems can be studied since the availability of genomes and post-genomic technologies is beyond what most people could have imagined...... previously. The fungal genera Aspergillus and Penicillium contain some species that are amongst the most widely used industrial microorganisms and others that are serious pathogens of plants, animals and humans. These genera are also at the forefront of fungal genomics with many genome sequences available...

  6. The population genomics of mycotoxin diversity in Aspergillus flavus and Aspergillus parasiticus

    Science.gov (United States)

    Mycotoxins, and especially the aflatoxins, are an enormous problem in agriculture, with aflatoxin B1 being the most carcinogenic known natural compound. The worldwide costs associated with aflatoxin monitoring and crop losses are in the hundreds of millions of dollars. Aspergillus flavus and A. par...

  7. Draft Genome Sequence of Aspergillus niger Strain An76

    OpenAIRE

    Gong, Weili; Cheng, Zhi; Zhang, Huaiqiang; Liu, Lin; Gao, Peiji; Wang, Lushan

    2016-01-01

    The filamentous fungus Aspergillus niger has become one of the most important fungi in industrial biotechnology, and it can efficiently secrete both polysaccharide-degrading enzymes and organic acids. We report here the 6,074,961,332-bp draft sequence of A. niger strain An76, and the findings provide important information related to its lignocellulose-degrading ability.

  8. Genome sequencing and analysis of the versatile cell factory Aspergillus niger CBS 513.88

    DEFF Research Database (Denmark)

    Pel, Herman J.; de Winde, Johannes H.; Archer, David B.;

    2007-01-01

    The filamentous fungus Aspergillus niger is widely exploited by the fermentation industry for the production of enzymes and organic acids, particularly citric acid. We sequenced the 33.9-megabase genome of A. niger CBS 513.88, the ancestor of currently used enzyme production strains. A high level...

  9. Genome Sequences of Eight Aspergillus flavus spp. and One A. parasiticus sp., Isolated from Peanut Seeds in Georgia

    Science.gov (United States)

    Wang, Xinye Monica; Palencia, Edwin R.

    2016-01-01

    Aspergillus flavus and A. parasiticus fungi produce carcinogenic mycotoxins in peanut seeds, causing considerable impact on both human health and the economy. Here, we report nine genome sequences of Aspergillus spp., isolated from Georgia peanut seeds in 2014. The information obtained will lead to further biodiversity studies that are essential for developing control strategies. PMID:27081142

  10. Genome Sequences of Eight Aspergillus flavus spp. and One A. parasiticus sp., Isolated From Peanut Seeds in Georgia

    Science.gov (United States)

    Aspergillus flavus and A. parasiticus fungi, carcinogen-mycotoxins producers, infect peanut seeds, causing considerable impact on both human health and the economy. Here we report 9 genome sequences of Aspergillus spp. isolated from peanut seeds. The information obtained will allow conducting biodiv...

  11. Versatile Enzyme Expression and Characterization System for Aspergillus nidulans, with the Penicillium brevicompactum Polyketide Synthase Gene from the Mycophenolic Acid Gene Cluster as a Test Case

    DEFF Research Database (Denmark)

    Hansen, Bjarne Gram; Salomonsen, Bo; Nielsen, Morten Thrane;

    2011-01-01

    Assigning functions to newly discovered genes constitutes one of the major challenges en route to fully exploiting the data becoming available from the genome sequencing initiatives. Heterologous expression in an appropriate host is central in functional genomics studies. In this context, filamen...

  12. What can comparative genomics tell us about species concepts in the genus Aspergillus?

    Energy Technology Data Exchange (ETDEWEB)

    Rokas, Antonis; payne, gary; Federova, Natalie D.; Baker, Scott E.; Machida, Masa; yu, Jiujiang; georgianna, D. R.; Dean, Ralph A.; Bhatnagar, Deepak; Cleveland, T. E.; Wortman, Jennifer R.; Maiti, R.; Joardar, V.; Amedeo, Paolo; Denning, David W.; Nierman, William C.

    2007-12-15

    Understanding the nature of species" boundaries is a fundamental question in evolutionary biology. The availability of genomes from several species of the genus Aspergillus allows us for the first time to examine the demarcation of fungal species at the whole-genome level. Here, we examine four case studies, two of which involve intraspecific comparisons, whereas the other two deal with interspecific genomic comparisons between closely related species. These four comparisons reveal significant variation in the nature of species boundaries across Aspergillus. For example, comparisons between A. fumigatus and Neosartorya fischeri (the teleomorph of A. fischerianus) and between A. oryzae and A. flavus suggest that measures of sequence similarity and species-specific genes are significantly higher for the A. fumigatus - N. fischeri pair. Importantly, the values obtained from the comparison between A. oryzae and A. flavus are remarkably similar to those obtained from an intra-specific comparison of A. fumigatus strains, giving support to the proposal that A. oryzae represents a distinct ecotype of A. flavus and not a distinct species. We argue that genomic data can aid Aspergillus taxonomy by serving as a source of novel and unprecedented amounts of comparative data, as a resource for the development of additional diagnostic tools, and finally as a knowledge database about the biological differences between strains and species.

  13. Recent advances in genome mining of secondary metabolites in Aspergillus terreus

    OpenAIRE

    Guo, Chun-Jun; Wang, Clay C. C.

    2014-01-01

    Filamentous fungi are rich resources of secondary metabolites (SMs) with a variety of interesting biological activities. Recent advances in genome sequencing and techniques in genetic manipulation have enabled researchers to study the biosynthetic genes of these SMs. Aspergillus terreus is the well-known producer of lovastatin, a cholesterol-lowering drug. This fungus also produces other SMs, including acetylaranotin, butyrolactones, and territram, with interesting bioactivities. This review ...

  14. Signaling pathways for stress responses and adaptation in Aspergillus species: stress biology in the post-genomic era.

    Science.gov (United States)

    Hagiwara, Daisuke; Sakamoto, Kazutoshi; Abe, Keietsu; Gomi, Katsuya

    2016-09-01

    Aspergillus species are among the most important filamentous fungi in terms of industrial use and because of their pathogenic or toxin-producing features. The genomes of several Aspergillus species have become publicly available in this decade, and genomic analyses have contributed to an integrated understanding of fungal biology. Stress responses and adaptation mechanisms have been intensively investigated using the accessible genome infrastructure. Mitogen-activated protein kinase (MAPK) cascades have been highlighted as being fundamentally important in fungal adaptation to a wide range of stress conditions. Reverse genetics analyses have uncovered the roles of MAPK pathways in osmotic stress, cell wall stress, development, secondary metabolite production, and conidia stress resistance. This review summarizes the current knowledge on the stress biology of Aspergillus species, illuminating what we have learned from the genomic data in this "post-genomic era." PMID:27007956

  15. Recent advances in genome mining of secondary metabolites in Aspergillus terreus

    Directory of Open Access Journals (Sweden)

    Clay Chia Chun Wang

    2014-12-01

    Full Text Available Filamentous fungi are rich resources of secondary metabolites (SMs with a variety of interesting biological activities. Recent advances in genome sequencing and techniques in genetic manipulation have enabled researchers to study the biosynthetic genes of these SMs. Aspergillus terreus is the well-known producer of lovastatin, a cholesterol-lowering drug. This fungus also produces other SMs, including acetylaranotin, butyrolactones and territram, with interesting bioactivities. This review will cover recent progress in genome mining of SMs identified in this fungus. The identification and characterization of the gene cluster for these SMs, as well as the proposed biosynthetic pathways, will be discussed in depth.

  16. Aspergillus: a primer for the novice.

    Science.gov (United States)

    Bennett, J W

    2009-01-01

    Aspergillus is a genus of molds named after the morphological structure that bears asexual spores, the aspergillum, which resembles a liturgical device. This genus contains several species of positive or negative economic importance in industry, agriculture and medicine. The majority of aspergilli, including most species of economic importance, are known to reproduce only by asexual spores. Genome projects have been completed for A. fumigatus, A. nidulans, A. niger and A. oryzae; several other species are also being sequenced. The data from these genome projects have been useful in elucidating aspects of phylogeny, the evolution of sexuality and the extent of secondary metabolite diversity. To date, however, the impact on drug discovery, diagnosis of aspergillosis, and our understanding of fungal pathogenesis has been less pronounced. PMID:19253144

  17. Cryptic Sexuality in Aspergillus parasiticus and A. flavus

    Science.gov (United States)

    Ascomycetous fungi of the genus Aspergillus comprise a wide variety of species of biotechnological importance (e.g. A. sojae, A. oryzae, A. niger) as well as pathogens and toxin producers (e.g. A. flavus, A. parasiticus, A. fumigatus, A. nidulans). With the exception of A. nidulans, which is a homot...

  18. Whole genome evaluation of horizontal transfers in the pathogenic fungus Aspergillus fumigatus

    Directory of Open Access Journals (Sweden)

    Deschavanne Patrick

    2010-03-01

    Full Text Available Abstract Background Numerous cases of horizontal transfers (HTs have been described for eukaryote genomes, but in contrast to prokaryote genomes, no whole genome evaluation of HTs has been carried out. This is mainly due to a lack of parametric methods specially designed to take the intrinsic heterogeneity of eukaryote genomes into account. We applied a simple and tested method based on local variations of genomic signatures to analyze the genome of the pathogenic fungus Aspergillus fumigatus. Results We detected 189 atypical regions containing 214 genes, accounting for about 1 Mb of DNA sequences. However, the fraction of atypical DNA detected was smaller than the average amount detected in the same conditions in prokaryote genomes (3.1% vs 5.6%. It appeared that about one third of these regions contained no annotated genes, a proportion far greater than in prokaryote genomes. When analyzing the origin of these HTs by comparing their signatures to a home made database of species signatures, 3 groups of donor species emerged: bacteria (40%, fungi (25%, and viruses (22%. It is to be noticed that though inter-domain exchanges are confirmed, we only put in evidence very few exchanges between eukaryotic kingdoms. Conclusions In conclusion, we demonstrated that HTs are not negligible in eukaryote genomes, bearing in mind that in our stringent conditions this amount is a floor value, though of a lesser extent than in prokaryote genomes. The biological mechanisms underlying those transfers remain to be elucidated as well as the biological functions of the transferred genes.

  19. Exploiting proteomic data for genome annotation and gene model validation in Aspergillus niger

    Directory of Open Access Journals (Sweden)

    Grigoriev Igor V

    2009-02-01

    Full Text Available Abstract Background Proteomic data is a potentially rich, but arguably unexploited, data source for genome annotation. Peptide identifications from tandem mass spectrometry provide prima facie evidence for gene predictions and can discriminate over a set of candidate gene models. Here we apply this to the recently sequenced Aspergillus niger fungal genome from the Joint Genome Institutes (JGI and another predicted protein set from another A.niger sequence. Tandem mass spectra (MS/MS were acquired from 1d gel electrophoresis bands and searched against all available gene models using Average Peptide Scoring (APS and reverse database searching to produce confident identifications at an acceptable false discovery rate (FDR. Results 405 identified peptide sequences were mapped to 214 different A.niger genomic loci to which 4093 predicted gene models clustered, 2872 of which contained the mapped peptides. Interestingly, 13 (6% of these loci either had no preferred predicted gene model or the genome annotators' chosen "best" model for that genomic locus was not found to be the most parsimonious match to the identified peptides. The peptides identified also boosted confidence in predicted gene structures spanning 54 introns from different gene models. Conclusion This work highlights the potential of integrating experimental proteomics data into genomic annotation pipelines much as expressed sequence tag (EST data has been. A comparison of the published genome from another strain of A.niger sequenced by DSM showed that a number of the gene models or proteins with proteomics evidence did not occur in both genomes, further highlighting the utility of the method.

  20. Improved annotation through genome-scale metabolic modeling of Aspergillus oryzae

    DEFF Research Database (Denmark)

    Vongsangnak, Wanwipa; Olsen, Peter; Hansen, Kim;

    2008-01-01

    Background: Since ancient times the filamentous fungus Aspergillus oryzae has been used in the fermentation industry for the production of fermented sauces and the production of industrial enzymes. Recently, the genome sequence of A. oryzae with 12,074 annotated genes was released but the number...... of hypothetical proteins accounted for more than 50% of the annotated genes. Considering the industrial importance of this fungus, it is therefore valuable to improve the annotation and further integrate genomic information with biochemical and physiological information available for this microorganism and other...... related fungi. Here we proposed the gene prediction by construction of an A. oryzae Expressed Sequence Tag (EST) library, sequencing and assembly. We enhanced the function assignment by our developed annotation strategy. The resulting better annotation was used to reconstruct the metabolic network leading...

  1. Genome Sequences of Eight Aspergillus flavus spp. and One A. parasiticus sp., Isolated from Peanut Seeds in Georgia.

    Science.gov (United States)

    Faustinelli, Paola C; Wang, Xinye Monica; Palencia, Edwin R; Arias, Renée S

    2016-01-01

    Aspergillus flavusandA. parasiticusfungi produce carcinogenic mycotoxins in peanut seeds, causing considerable impact on both human health and the economy. Here, we report nine genome sequences ofAspergillusspp., isolated from Georgia peanut seeds in 2014. The information obtained will lead to further biodiversity studies that are essential for developing control strategies. PMID:27081142

  2. Comparative genomics of citric-acid-producing Aspergillus niger ATCC 1015 versus enzyme-producing CBS 513.88

    DEFF Research Database (Denmark)

    Andersen, Mikael Rørdam; Salazar, Margarita Pena; Schaap, Peter J.;

    2011-01-01

    The filamentous fungus Aspergillus niger exhibits great diversity in its phenotype. It is found globally, both as marine and terrestrial strains, produces both organic acids and hydrolytic enzymes in high amounts, and some isolates exhibit pathogenicity. Although the genome of an industrial enzym...

  3. Aflatoxin B1-producing Aspergillus in sun-dried medicinal plant materials

    OpenAIRE

    Chinaputi, A.; Lim, S; Petcharat, V.; Chuenchit, S.; Pathanadech, A.

    2001-01-01

    Fifty sun-dried medicinal plants were obtained from fraditional drug stores in Songkhla Province, Thailand, and examined for Aspergillus and aflatoxin B1. 288 isolates of Aspergillus were obtaines by standard blotter plate and 25 species were identified. The most common species were A. niger with 99 isolates, A. Flavus 84 isolates, A. terreus 33 isolates, A. oryzae 25 isolates, A.nidulans (Emericella nidulans) 10 isolates, A fumigatus 9 isolates and A. chevalieri (Eurotium chevalieri) 8 isola...

  4. Characterization of oxylipins and dioxygenase genes in the asexual fungus Aspergillus niger

    Directory of Open Access Journals (Sweden)

    Kalkhove Stefanie IC

    2009-03-01

    Full Text Available Abstract Background Aspergillus niger is an ascomycetous fungus that is known to reproduce through asexual spores, only. Interestingly, recent genome analysis of A. niger has revealed the presence of a full complement of functional genes related to sexual reproduction 1. An example of such genes are the dioxygenase genes which in Aspergillus nidulans, have been shown to be connected to oxylipin production and regulation of both sexual and asexual sporulation 234. Nevertheless, the presence of sex related genes alone does not confirm sexual sporulation in A. niger. Results The current study shows experimentally that A. niger produces the oxylipins 8,11-dihydroxy octadecadienoic acid (8,11-diHOD, 5,8-dihydroxy octadecadienoic acid (5,8-diHOD, lactonized 5,8-diHOD, 8-hydroxy octadecadienoic acid (8-HOD, 10-hydroxy octadecadienoic acid (10-HOD, small amounts of 8-hydroxy octadecamonoenoic acid (8-HOM, 9-hydroxy octadecadienoic acid (9-HOD and 13-hydroxy octadecadienoic acid (13-HOD. Importantly, this study shows that the A. niger genome contains three putative dioxygenase genes, ppoA, ppoC and ppoD. Expression analysis confirmed that all three genes are indeed expressed under the conditions tested. Conclusion A. niger produces the same oxylipins and has similar dioxygenase genes as A. nidulans. Their presence could point towards the existence of sexual reproduction in A. niger or a broader role for the gene products in physiology, than just sexual development.

  5. Analysis and prediction of gene splice sites in four Aspergillus genomes

    DEFF Research Database (Denmark)

    Wang, Kai; Ussery, David; Brunak, Søren

    2009-01-01

    , splice site prediction program called NetAspGene, for the genus Aspergillus. Gene sequences from Aspergillus fumigatus, the most common mould pathogen, were used to build and test our model. Compared to many animals and plants, Aspergillus contains smaller introns; thus we have applied a larger window...... better splice site prediction than other available tools. NetAspGene will be very helpful for the study in Aspergillus splice sites and especially in alternative splicing. A webpage for NetAspGene is publicly available at http://www.cbs.dtu.dk/services/NetAspGene....

  6. Functional Genomic Analysis of Aspergillus flavus Interacting with Resistant and Susceptible Peanut

    Directory of Open Access Journals (Sweden)

    Houmiao Wang

    2016-02-01

    Full Text Available In the Aspergillus flavus (A. flavus–peanut pathosystem, development and metabolism of the fungus directly influence aflatoxin contamination. To comprehensively understand the molecular mechanism of A. flavus interaction with peanut, RNA-seq was used for global transcriptome profiling of A. flavus during interaction with resistant and susceptible peanut genotypes. In total, 67.46 Gb of high-quality bases were generated for A. flavus-resistant (af_R and -susceptible peanut (af_S at one (T1, three (T2 and seven (T3 days post-inoculation. The uniquely mapped reads to A. flavus reference genome in the libraries of af_R and af_S at T2 and T3 were subjected to further analysis, with more than 72% of all obtained genes expressed in the eight libraries. Comparison of expression levels both af_R vs. af_S and T2 vs. T3 uncovered 1926 differentially expressed genes (DEGs. DEGs associated with mycelial growth, conidial development and aflatoxin biosynthesis were up-regulated in af_S compared with af_R, implying that A. flavus mycelia more easily penetrate and produce much more aflatoxin in susceptible than in resistant peanut. Our results serve as a foundation for understanding the molecular mechanisms of aflatoxin production differences between A. flavus-R and -S peanut, and offer new clues to manage aflatoxin contamination in crops.

  7. Sporogenic Effect of Polyunsaturated Fatty Acids on Development of Aspergillus spp.

    OpenAIRE

    Calvo, Ana M.; Hinze, Lori L.; Gardner, Harold W.; Keller, Nancy P

    1999-01-01

    Aspergillus spp. are frequently occurring seed-colonizing fungi that complete their disease cycles through the development of asexual spores, which function as inocula, and through the formation of cleistothecia and sclerotia. We found that development of all three of these structures in Aspergillus nidulans, Aspergillus flavus, and Aspergillus parasiticus is affected by linoleic acid and light. The specific morphological effects of linoleic acid include induction of precocious and increased ...

  8. Genome wide association mapping of Aspergillus flavus and aflatoxin accumulation resistance in maize

    Science.gov (United States)

    Contamination of maize with aflatoxin, produced by the fungus Aspergillus flavus, has severe health and economic consequences. Efforts to reduce aflatoxin accumulation in maize have focused on identifying and selecting germplasm with natural host resistance factors, and several maize lines with sign...

  9. Aspergillus flavus whole genome and EST sequence releases and construction of homologous gene search blast server

    Science.gov (United States)

    Aflatoxins are toxic and carcinogenic secondary metabolites. These compounds, produced by Aspergillus flavus and A. parasiticus, contaminate pre-harvest agricultural crops in the field and post-harvest grains during storage. In order to reduce and eliminate aflatoxin contamination of food and feed...

  10. Aspergillus flavus Genomic Data Mining Provides Clues for Its Use in Producing Biobased Products

    Science.gov (United States)

    Aspergillus flavus is notorious for its ability to produce aflatoxins. It is also an opportunistic pathogen that infects plants, animals and human beings. The ability to survive in the natural environment, living on plant tissues (leaves or stalks), live or dead insects make A. flavus a ubiquitous...

  11. Draft genome sequences of two closely-related aflatoxigenic Aspergillus species obtained from the Ivory Coast

    Science.gov (United States)

    The genomes of the A. ochraceoroseus and A. rambellii type strains were sequenced using a personal genome machine, followed by annotation of their genes. The genome size for A. ochraceoroseus was found to be approximately 23 Mb and contained 7,837 genes, while the A. rambellii genome was found to be...

  12. Mutagenesis and mitotic recombination in Aspergillus niger, an expedition from gene to genome

    OpenAIRE

    Vondervoort, Peter Jozef Ida van de

    2007-01-01

    Aspergillus niger is a cosmopolitan fungus and its spores can be found in air and soil worldwide. This saprophyte is used in food biotechnology for the production of proteins, mainly enzymes and for the production of organic acids. In the production of proteins, several problems are encountered such as repressed gene-expression, morphologic and genetic instability and undesired metabolite accumulation. To find solutions to these problems, often mutagenesis and mitotic recombination have been ...

  13. Assessment of the pectinolytic network of Aspergillus niger by functional genomics : insights from the transcriptome

    OpenAIRE

    Martens-Uzunova, E S

    2008-01-01

    More than a century ago, in 1889, A. Fernbach presented a detailed report about the invertase of Aspergillus niger in the third edition of “Annales De L'institut Pasteur”. Since then, many of the enzymes secreted by A. niger have found a broad range of applications, and today they are produced on an industrial scale. This filamentous fungus is also used as a primary source for the production of organic acids and other economically important metabolites. Although, many of these fermentation pr...

  14. Genome-based Characterization of Two Prenylation Steps in the Assembly of the Stephacidin and Notoamide Anticancer Agents in a Marine-derived Aspergillus sp

    OpenAIRE

    Ding, Yousong; de Wet, Jeffrey R.; Cavalcoli, James; Li, Shengying; Greshock, Thomas J.; Miller, Kenneth A.; Finefield, Jennifer M.; Sunderhaus, James D.; McAfoos, Timothy; Tsukamoto, Sachiko; Williams, Robert M.; Sherman, David H.

    2010-01-01

    Stephacidin and notoamide natural products belong to a group of prenylated indole alkaloids containing a core bicyclo[2.2.2]diazaoctane ring system. These bioactive fungal secondary metabolites have a range of unusual structural and stereochemical features but their biosynthesis has remained uncharacterized. Herein, we report the first biosynthetic gene cluster for this class of fungal alkaloids based on whole genome sequencing of a marine-derived Aspergillus sp. Two central pathway enzymes c...

  15. Biosynthetic Pathway for the Epipolythiodioxopiperazine Acetylaranotin in Aspergillus terreus Revealed by Genome-based Deletion Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Chun-Jun; Yeh, Hsu-Hua; Chiang, Yi Ming; Sanchez, James F.; Chang, ShuLin; Bruno, Kenneth S.; Wang, Clay C.

    2013-04-15

    Abstract Epipolythiodioxopiperazines (ETPs) are a class of fungal secondary metabolites derived from cyclic peptides. Acetylaranotin belongs to one structural subgroup of ETPs characterized by the presence of a seven-membered dihydrooxepine ring. Defining the genes involved in acetylaranotin biosynthesis should provide a means to increase production of these compounds and facilitate the engineering of second-generation molecules. The filamentous fungus Aspergillus terreus produces acetylaranotin and related natural products. Using targeted gene deletions, we have identified a cluster of 9 genes including one nonribosomal peptide synthase gene, ataP, that is required for acetylaranotin biosynthesis. Chemical analysis of the wild type and mutant strains enabled us to isolate seventeen natural products that are either intermediates in the normal biosynthetic pathway or shunt products that are produced when the pathway is interrupted through mutation. Nine of the compounds identified in this study are novel natural products. Our data allow us to propose a complete biosynthetic pathway for acetylaranotin and related natural products.

  16. Comparative genomics of citric-acid producing Aspergillus niger ATCC 1015 versus enzyme-producing CBS 513.88

    Energy Technology Data Exchange (ETDEWEB)

    Grigoriev, Igor V.; Baker, Scott E.; Andersen, Mikael R.; Salazar, Margarita P.; Schaap, Peter J.; Vondervoot, Peter J.I. van de; Culley, David; Thykaer, Jette; Frisvad, Jens C.; Nielsen, Kristen F.; Albang, Richard; Albermann, Kaj; Berka, Randy M.; Braus, Gerhard H.; Braus-Stromeyer, Susanna A.; Corrochano, Luis M.; Dai, Ziyu; Dijck, Piet W.M. van; Hofmann, Gerald; Lasure, Linda L.; Magnusson, Jon K.; Meijer, Susan L.; Nielsen, Jakob B.; Nielsen, Michael L.; Ooyen, Albert J.J. van; Panther, Kathyrn S.; Pel, Herman J.; Poulsen, Lars; Samson, Rob A.; Stam, Hen; Tsang, Adrian; Brink, Johannes M. van den; Atkins, Alex; Aerts, Andrea; Shapiro, Harris; Pangilinan, Jasmyn; Salamov, Asaf; Lou, Yigong; Lindquist, Erika; Lucas, Susan; Grimwood, Jane; Kubicek, Christian P.; Martinez, Diego; Peij, Noel N.M.E. van; Roubos, Johannes A.; Nielsen, Jens

    2011-04-28

    The filamentous fungus Aspergillus niger exhibits great diversity in its phenotype. It is found globally, both as marine and terrestrial strains, produces both organic acids and hydrolytic enzymes in high amounts, and some isolates exhibit pathogenicity. Although the genome of an industrial enzyme-producing A. niger strain (CBS 513.88) has already been sequenced, the versatility and diversity of this species compels additional exploration. We therefore undertook whole genome sequencing of the acidogenic A. niger wild type strain (ATCC 1015), and produced a genome sequence of very high quality. Only 15 gaps are present in the sequence and half the telomeric regions have been elucidated. Moreover, sequence information from ATCC 1015 was utilized to improve the genome sequence of CBS 513.88. Chromosome-level comparisons uncovered several genome rearrangements, deletions, a clear case of strain-specific horizontal gene transfer, and identification of 0.8 megabase of novel sequence. Single nucleotide polymorphisms per kilobase (SNPs/kb) between the two strains were found to be exceptionally high (average: 7.8, maximum: 160 SNPs/kb). High variation within the species was confirmed with exo-metabolite profiling and phylogenetics. Detailed lists of alleles were generated, and genotypic differences were observed to accumulate in metabolic pathways essential to acid production and protein synthesis. A transcriptome analysis revealed up-regulation of the electron transport chain, specifically the alternative oxidative pathway in ATCC 1015, while CBS 513.88 showed significant up-regulation of genes relevant to glucoamylase A production, such as tRNA-synthases and protein transporters. Our results and datasets from this integrative systems biology analysis resulted in a snapshot of fungal evolution and will support further optimization of cell factories based on filamentous fungi.[Supplemental materials (10 figures, three text documents and 16 tables) have been made available

  17. Negative regulation and developmental competence in Aspergillus.

    Science.gov (United States)

    Lee, Mi-Kyung; Kwon, Nak-Jung; Lee, Im-Soon; Jung, Seunho; Kim, Sun-Chang; Yu, Jae-Hyuk

    2016-01-01

    Asexual development (conidiation) in the filamentous fungus Aspergillus nidulans is governed by orchestrated gene expression. The three key negative regulators of conidiation SfgA, VosA, and NsdD act at different control point in the developmental genetic cascade. Here, we have revealed that NsdD is a key repressor affecting the quantity of asexual spores in Aspergillus. Moreover, nullifying both nsdD and vosA results in abundant formation of the development specific structure conidiophores even at 12 h of liquid culture, and near constitutive activation of conidiation, indicating that acquisition of developmental competence involves the removal of negative regulation exerted by both NsdD and VosA. NsdD's role in repressing conidiation is conserved in other aspergilli, as deleting nsdD causes enhanced and precocious activation of conidiation in Aspergillus fumigatus or Aspergillus flavus. In vivo NsdD-DNA interaction analyses identify three NsdD binding regions in the promoter of the essential activator of conidiation brlA, indicating a direct repressive role of NsdD in conidiation. Importantly, loss of flbC or flbD encoding upstream activators of brlA in the absence of nsdD results in delayed activation of brlA, suggesting distinct positive roles of FlbC and FlbD in conidiation. A genetic model depicting regulation of conidiation in A. nidulans is presented. PMID:27364479

  18. Biotransformation von 11-Desoxycortisol mit Schizosaccharomyces pombe und Aspergillus nidulans

    OpenAIRE

    Appel, Daniel

    2005-01-01

    In diesem Projekt, welches in Kooperation mit dem Institut für Biochemie der Universität des Saarlandes und der Schering AG Bergkamen durchgeführt wurde, sollte mit Hilfe von rekombinanten Spalthefestämmen, welche die humane Monooxygenase P450 CYP11B1 exprimieren, eine nachhaltigere Bio-Produktion von Hydrocortison entwickelt werden, um das bestehende Verfahren der Hydrocortisonherstellung, mittels des filamentösen Pilz Curvularia lunata zu ersetzen. Um die Optimierung der Hydrocortisonpro...

  19. Expression and characterization of an endo-1,4-β-galactanase from Emericella nidulans in Pichia pastoris for enzymatic design of potentially prebiotic oligosaccharides from potato galactans

    DEFF Research Database (Denmark)

    Michalak, Malwina; Thomassen, Lise Vestergaard; Roytio, Henna;

    2012-01-01

    Potato pulp is a high-volume side-stream from industrial potato starch manufacturing. Enzymatically solubilized β-1,4-galactan-rich potato pulp polysaccharides of molecular weights >100kDa (SPPP) are highly bifidogenic in human fecal sample fermentations in vitro. The objective of the present study...... was to use potato β-1,4-galactan and the SPPP as substrates for enzymatic production of potentially prebiotic compounds of lower and narrower molecular weight. A novel endo-1,4-β-galactanase from Emericella nidulans (anamorph Aspergillus nidulans), GH family 53, was produced in a recombinant Pichia...... pastoris strain. The enzyme was purified by Cu2+ affinity chromatography and its optimal reaction conditions were determined to pH 5 and 49°C via a statistical experimental design. The specific activity of the E. nidulans enzyme expressed in P. pastoris was similar to that of an endo-1,4-β-galactanase from...

  20. Effect of serum components on biofilm formation by Aspergillus fumigatus and other Aspergillus species.

    Science.gov (United States)

    Wuren, Tuya; Toyotome, Takahito; Yamaguchi, Masashi; Takahashi-Nakaguchi, Azusa; Muraosa, Yasunori; Yahiro, Maki; Wang, Dan-Ni; Watanabe, Akira; Taguchi, Hideaki; Kamei, Katsuhiko

    2014-01-01

    Biofilm production by microorganisms is critical for their pathogenicity. Serum promotes biofilm production by Aspergillus fumigatus; however, its effects on other Aspergillus spp. have not been reported. We analyzed biofilm formation by five Aspergillus spp., i.e., A. fumigatus, A. flavus, A. nidulans, A. niger, and A. terreus, and examined the effects of serum/serum proteins such as fetal bovine serum (FBS), fetuin A, and bovine serum albumin (BSA) on hyphal growth, hyphal branching, and extracellular matrix (ECM) formation. The antifungal susceptibility of A. fumigatus isolates that formed biofilms was also examined. All serum/serum proteins promoted the growth of all these fungal species; growth promotion was most evident with FBS, followed by fetuin A and BSA. This effect was most evident in case of A. fumigatus and least evident in case of A. terreus. Electron microscopy showed thick ECM layers surrounding fungal cell walls after culture with FBS, particularly in A. fumigatus. An increase in hyphal branching caused by fetuin A was the highest in case of A. fumigatus and A. nidulans. Biofilm-forming A. fumigatus showed resistance to most antifungal agents, although a synergism of micafungin and amphotericin B was suggested. Our results indicate that serum promotes biofilm formation, including thick ECM, by many Aspergillus spp., particularly A. fumigatus, and that this may be closely related to its virulence. PMID:24858605

  1. Upstream and Downstream Regulation of Asexual Development in Aspergillus fumigatus†

    OpenAIRE

    Mah, Jae-Hyung; Yu, Jae-Hyuk

    2006-01-01

    The opportunistic human pathogen Aspergillus fumigatus produces a large quantity of asexual spores (conidia), which are the primary agent causing invasive aspergillosis in immunocompromised patients. We investigated the mechanisms controlling asexual sporulation (conidiation) in A. fumigatus via examining functions of four key regulators, GpaA (Gα), AfFlbA (RGS), AfFluG, and AfBrlA, previously studied in Aspergillus nidulans. Expression analyses of gpaA, AfflbA, AffluG, AfbrlA, and AfwetA thr...

  2. Suppression of Aspergillus by Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Jensen, Britt Guillaume; Jelsbak, Lars; Søndergaard, Ib;

    suppressed growth of A. fumigatus, A. niger, A. flavus, A. oryzae, A. terreus and E. nidulans. HPLC and LC-DAD-MS results showed an increase in phenazine-1-carboxylic acid and phenazine-1-carboxamide production by P. aeruginosa in the contact area of Aspergillus. Different quinolones were also identified......, here among 2-heptyl-3-hydroxy-4-quinolone (PQS). An unidentified green pseudomonas compound was also observed. Interestingly the P. aeruginosa mutant rpoN was unable to suppress A. fumigatus, but suppressed A. flavus, A. oryzae and A. niger. However several other P. aeruginosa mutants suppressed A...

  3. The Putative Guanine Nucleotide Exchange Factor RicA Mediates Upstream Signaling for Growth and Development in Aspergillus

    OpenAIRE

    Kwon, Nak-Jung; Park, Hee-Soo; Jung, Seunho; Kim, Sun Chang; Yu, Jae-Hyuk

    2012-01-01

    Heterotrimeric G proteins (G proteins) govern growth, development, and secondary metabolism in various fungi. Here, we characterized ricA, which encodes a putative GDP/GTP exchange factor for G proteins in the model fungus Aspergillus nidulans and the opportunistic human pathogen Aspergillus fumigatus. In both species, ricA mRNA accumulates during vegetative growth and early developmental phases, but it is not present in spores. The deletion of ricA results in severely impaired colony growth ...

  4. Genome sequence of Aspergillus flavus NRRL 3357, a strain that causes aflatoxin contamination of food and feed

    Science.gov (United States)

    Aflatoxin contamination of food and livestock feed results in significant annual crop losses internationally. Aspergillus flavus is the major fungus responsible for this loss. Additionally, A. flavus is the second leading cause of aspergillosis in immune compromised human patients. Here we report th...

  5. Three extracellular dipeptidyl peptidases found in Aspergillus oryzae show varying substrate specificities.

    Science.gov (United States)

    Maeda, Hiroshi; Sakai, Daisuke; Kobayashi, Takuji; Morita, Hiroto; Okamoto, Ayako; Takeuchi, Michio; Kusumoto, Ken-Ichi; Amano, Hitoshi; Ishida, Hiroki; Yamagata, Youhei

    2016-06-01

    Three extracellular dipeptidyl peptidase genes, dppB, dppE, and dppF, were unveiled by sequence analysis of the Aspergillus oryzae genome. We investigated their differential enzymatic profiles, in order to gain an understanding of the diversity of these genes. The three dipeptidyl peptidases were expressed using Aspergillus nidulans as the host. Each recombinant enzyme was purified and subsequently characterized. The enzymes displayed similar optimum pH values, but optimum temperatures, pH stabilities, and substrate specificities varied. DppB was identified as a Xaa-Prolyl dipeptidyl peptidase, while DppE scissile substrates were similar to the substrates for Aspergillus fumigatus DPPV (AfDPPV). DppF was found to be a novel enzyme that could digest both substrates for A. fumigatus DPPIV and AfDPPV. Semi-quantitative PCR revealed that the transcription of dppB in A. oryzae was induced by protein substrates and repressed by the addition of an inorganic nitrogen source, despite the presence of protein substrates. The transcription of dppE depended on its growth time, while the transcription of dppF was not affected by the type of the nitrogen source in the medium, and it started during the early stage of the fungal growth. Based on these results, we conclude that these enzymes may represent the nutrition acquisition enzymes. Additionally, DppF may be one of the sensor peptidases responsible for the detection of the protein substrates in A. oryzae environment. DppB may be involved in nitrogen assimilation control, since the transcription of dppB was repressed by NaNO3, despite the presence of protein substrates. PMID:26846741

  6. Construction of a promoter probe vector autonomously maintained in Aspergillus and characterization of promoter regions derived from A. niger and A. oryzae genomes.

    Science.gov (United States)

    Ozeki, K; Kanda, A; Hamachi, M; Nunokawa, Y

    1996-03-01

    We used a plasmid carrying a sequence for autonomous maintenance in Aspergillus (AMA1) and the E. coli uidA gene as a reporter gene to search the A. oryzae and A. niger genomes for DNA fragments having strong promoter activity. Beta-glucuronidase (GUS)-producing A. oryzae transformants containing the No. 8AN derived from A. niger, or the No. 9AO derived from A. oryzae, were constitutive for the expression of the uidA gene when cultivated in the presence of a variety of carbon and nitrogen sources. When the GUS-producing transformants were grown in liquid culture, the No. 8AN showed an increase of approximately 3-fold in GUS activity compared to the amyB (alpha-amylase encoding gene) promoter. There was also a corresponding increase in the amount of GUS gene-specific mRNA. When these transformants were grown as rice-koji, the No. 8AN showed an increase of approximately 6-fold compared to the amyB promoter, and the amount of GUS protein produced also increased. These strong promoter regions might be applicable to the production of other heterologous proteins in Aspergillus species. PMID:8901095

  7. Fine de novo sequencing of a fungal genome using only SOLiD short read data: verification on Aspergillus oryzae RIB40.

    Directory of Open Access Journals (Sweden)

    Myco Umemura

    Full Text Available The development of next-generation sequencing (NGS technologies has dramatically increased the throughput, speed, and efficiency of genome sequencing. The short read data generated from NGS platforms, such as SOLiD and Illumina, are quite useful for mapping analysis. However, the SOLiD read data with lengths of <60 bp have been considered to be too short for de novo genome sequencing. Here, to investigate whether de novo sequencing of fungal genomes is possible using only SOLiD short read sequence data, we performed de novo assembly of the Aspergillus oryzae RIB40 genome using only SOLiD read data of 50 bp generated from mate-paired libraries with 2.8- or 1.9-kb insert sizes. The assembled scaffolds showed an N50 value of 1.6 Mb, a 22-fold increase than those obtained using only SOLiD short read in other published reports. In addition, almost 99% of the reference genome was accurately aligned by the assembled scaffold fragments in long lengths. The sequences of secondary metabolite biosynthetic genes and clusters, whose products are of considerable interest in fungal studies due to their potential medicinal, agricultural, and cosmetic properties, were also highly reconstructed in the assembled scaffolds. Based on these findings, we concluded that de novo genome sequencing using only SOLiD short reads is feasible and practical for molecular biological study of fungi. We also investigated the effect of filtering low quality data, library insert size, and k-mer size on the assembly performance, and recommend for the assembly use of mild filtered read data where the N50 was not so degraded and the library has an insert size of ∼2.0 kb, and k-mer size 33.

  8. Antifungal activity of oregano extract against A. Versicolor, E. Nidulans and Eurotium spp.: Producers of sterigmatocystin

    Directory of Open Access Journals (Sweden)

    Kocić-Tanackov Sunčica D.

    2011-01-01

    Full Text Available The paper presents the influence of oregano extract (Origanum vulgare L. on growth of Aspergillus versicolor, Emericella nidulans, Eurotium herbariorum, E. amstelodami, E. chevalieri and E. rubrum - producers of sterigmatocystin (STC isolated from salads. Antifungal tests were performed by agar plates method. The composition of the active component of extract was determined by GC-MS method and the major components were: carvacrol (34.20%, triacetin (22.91%, carvone (18.05%, p-cymene (8.05% and thymol (3.74%. The examined extract showed the ability to reduce mold growth at all applied concentrations. Minimum inhibitory concentrations (MIC for E. nidulans, E. chevalieri and E. amstelodami were 2.5% (v/v and over 2.5% (v/v for A. versicolor. At 1.5% (v/v concentration the extract completely inhibited the growth of E. rubrum, whereas higher dose of 2.5% (v/v was fungicidal against E. herbariorum. Besides its sensory role in food products, the examined oregano extract also exhibits antifungal activities against producers of STC.

  9. Recombinant bacterial hemoglobin alters metabolism of Aspergillus niger

    DEFF Research Database (Denmark)

    Hofmann, Gerald; Diano, Audrey; Nielsen, Jens

    2009-01-01

    The filamentous fungus Aspergillus niger is used extensively for the production of enzymes and organic acids. A major problem in industrial fermentations with this fungus is to ensure sufficient supply of oxygen required for respiratory metabolism of the fungus. In case of oxygen limitation, the ...... to attenuate unwanted side effects resulting from oxygen limitation during industrial fermentations with A. niger.......The filamentous fungus Aspergillus niger is used extensively for the production of enzymes and organic acids. A major problem in industrial fermentations with this fungus is to ensure sufficient supply of oxygen required for respiratory metabolism of the fungus. In case of oxygen limitation, the...... behind the strong gpdA promoter from Aspergillus nidulans. Analysis of secreted metabolites, oxygen uptake, CO2 evolution and biomass formation points towards a relief of stress in the mutant expressing VHB when it is exposed to oxygen limitation. Our findings therefore point to an interesting strategy...

  10. Transcriptional profiling of Aspergillus niger

    NARCIS (Netherlands)

    Veen, van der D.

    2009-01-01

    The industrially important fungus Aspergillus niger feeds naturally on decomposing plant material, of which a significant proportion is lipid. Examination of the A. niger genome sequence suggested that all proteins required for metabolic conversion of lipids are present, including 63 predicted lipas

  11. Uncovering transcriptional regulation of glycerol metabolism in Aspergilli through genome-wide gene expression data anlysis

    DEFF Research Database (Denmark)

    Salazar, Margarita Pena; Vongsangnak, Wanwipa; Panagiotou, Gianni;

    2009-01-01

    Glycerol is catabolized by a wide range of microorganisms including Aspergillus species. To identify the transcriptional regulation of glycerol metabolism in Aspergillus, we analyzed data from triplicate batch fermentations of three different Aspergilli (Aspergillus nidulans, Aspergillus oryzae and...... Aspergillus niger) with glucose and glycerol as carbon sources. Protein comparisons and cross-analysis with gene expression data of all three species resulted in the identification of 88 genes having a conserved response across the three Aspergilli. A promoter analysis of the up-regulated genes led to the...... identification of a conserved binding site for a putative regulator to be 5′-TGCGGGGA-3′, a binding site that is similar to the binding site for Adr1 in yeast and humans. We show that this Adr1 consensus binding sequence was over-represented on promoter regions of several genes in A. nidulans, A. oryzae and A...

  12. Purification and enzymatic characterization of secretory glycoside hydrolase family 3 (GH3) aryl β-glucosidases screened from Aspergillus oryzae genome.

    Science.gov (United States)

    Kudo, Kanako; Watanabe, Akira; Ujiie, Seiryu; Shintani, Takahiro; Gomi, Katsuya

    2015-12-01

    By a global search of the genome database of Aspergillus oryzae, we found 23 genes encoding putative β-glucosidases, among which 10 genes with a signal peptide belonging to glycoside hydrolase family 3 (GH3) were overexpressed in A. oryzae using the improved glaA gene promoter. Consequently, crude enzyme preparations from three strains, each harboring the genes AO090038000223 (bglA), AO090103000127 (bglF), and AO090003001511 (bglJ), showed a substrate preference toward p-nitrophenyl-β-d-glucopyranoside (pNPGlc) and thus were purified to homogeneity and enzymatically characterized. All the purified enzymes (BglA, BglF, and BglJ) preferentially hydrolyzed aryl β-glycosides, including pNPGlc, rather than cellobiose, and these enzymes were proven to be aryl β-glucosidases. Although the specific activity of BglF toward all the substrates tested was significantly low, BglA and BglJ showed appreciably high activities toward pNPGlc and arbutin. The kinetic parameters of BglA and BglJ for pNPGlc suggested that both the enzymes had relatively higher hydrolytic activity toward pNPGlc among the fungal β-glucosidases reported. The thermal and pH stabilities of BglA were higher than those of BglJ, and BglA was particularly stable in a wide pH range (pH 4.5-10). In contrast, BglJ was the most heat- and alkaline-labile among the three β-glucosidases. Furthermore, BglA was more tolerant to ethanol than BglJ; as a result, it showed much higher hydrolytic activity toward isoflavone glycosides in the presence of ethanol than BglJ. This study suggested that the mining of novel β-glucosidases exhibiting higher activity from microbial genome sequences is of great use for the production of beneficial compounds such as isoflavone aglycones. PMID:25936960

  13. Transcriptional profiling of Aspergillus niger

    OpenAIRE

    Veen, van der, J.T.

    2009-01-01

    The industrially important fungus Aspergillus niger feeds naturally on decomposing plant material, of which a significant proportion is lipid. Examination of the A. niger genome sequence suggested that all proteins required for metabolic conversion of lipids are present, including 63 predicted lipases. In contrast to polysaccharide-degrading enzyme networks, not much is known about the signaling and regulatory processes that control lipase expression and activity in fungi. This project was ai...

  14. Study on the molecular basis of glucoamylase overproduc-tion of a mutant strain Aspergillus niger T21

    Institute of Scientific and Technical Information of China (English)

    FAN; Xiaochun

    2001-01-01

    [1]Qiao, D., Tang, G., Zhong, L. et al., The overall analysis and comparison of the expression of glucoamylase in the over-production strain A. niger T21 and its original strain A. niger 3.795, Acta Microbiologica Sinica (in Chinese), 1997, 37(5): 349.[2]Zhong, L, Qiao, D, Tang, G. et al., Cloning, sequencing and comparison of the 5′-flanking regions of glaA gene from high and low glucoamylase producing strains of Aspergillus niger, Acta Microbiologica Sinica (in Chinese), 1996, 36: 181.[3]Qiao, D., Zhong, L., Tang, G. et al., Cloning and sequencing of glucoamylase gene from Aspergillus niger 3.795, Chinese J. Biochem. and Mol. Biology (in Chinese), 1998, 14: 254.[4]Zhong, L., Fan, X., Tang, G., Cotransformation of glucoamylase overproducing strain Aspergillus niger T21 with niaD and uidA gene, Mycosystema (in Chinese), 1999, 18: 172.[5]Roberts, I. N., Oliver, R. P., Punt, P. J. et al., Expression of the Escherichia coli b-glucuronidase gene in industrial and phytopathogenic filamentous fungi, Curr. Genet., 1989, 15: 177.[6]Lowry, O. H., Rosebrough, N. J., Farr, A. L. et al., Protein measurement with the folin phenol reagent, J. Biochem., 1951, 193: 268.[7]Zhu, H., Qu, F., Zhu, L., Isolation of genomic DNAs from fungi using benzyl chloride, Acta Mycologica Sinica (in Chi-nese), 1994, 13: 34.[8]Verwoerd, T. C., Dekker, B. M. M., Hoekema, A., A small-scale procedure for the rapid isolation of plant RNAs, Nucleic Acids Research, 1989, 17: 2362.[9]Campbell, E. I., Unkles, S. E., Marco, J. A. et al., Improved transformation efficiency of Aspergillus niger using the ho-mologous niaD gene for nitrate reductase, Curr. Genet., 1989, 16: 53.[10]Fowler, T., Berka, R. M., Ward, M., Regulation of the glaA gene of Aspergillus niger, Curr. Genet., 1990, 18: 537.[11]Verdoes, J. C., Punt, P. J., Stouthamer, A. H. et al., The effect of multiple copies of the upstream region on expression of the Aspergillus niger glucoamylase

  15. Hapalopilus nidulans (Polyporales: Polyporaceae a new record from India

    Directory of Open Access Journals (Sweden)

    C.K. Tiwari

    2011-06-01

    Full Text Available Hapalopilus nidulans (Polyporales: Polyporaceae is reported for the first time from India. It was collected on stored wood of Anogeissus latifolia, Chloroxylon swietenia, Ougeinia oojeinensis, Shorea robusta and Terminalia tomentosa from forest depots of Chhattisgarh, India. The species is being re-described on the basis of morphology, anatomy and cultural characters.

  16. The two genome sequence release and blast server construction for aflatoxin-producing L and S strains Aspergillus parasiticus and A. flavus

    Science.gov (United States)

    Aflatoxins are toxic and carcinogenic secondary metabolites. These compounds, produced by Aspergillus flavus and A. parasiticus, contaminate pre-harvest agricultural crops in the field and post-harvest grains during storage. In order to reduce and eliminate aflatoxin contamination of food and feed...

  17. Aspergillus niger genome-wide analysis reveals a large number of novel alpha-glucan acting enzymes with unexpected expression profiles

    NARCIS (Netherlands)

    Yuan, X.-L.; Kaaij, R.M. van der; Hondel, C.A.M.J.J. van den; Punt, P.J.; Maarel, M.J.E.C. van der; Dijkhuizen, L.; Ram, A.F.J.

    2008-01-01

    The filamentous ascomycete Aspergillus niger is well known for its ability to produce a large variety of enzymes for the degradation of plant polysaccharide material. A major carbon and energy source for this soil fungus is starch, which can be degraded by the concerted action of α-amylase, glucoamy

  18. RNA-Seq analysis of stuA mutants in Fusarium verticillioides indicates dramatic genomic wide transcriptional reprogramming

    Science.gov (United States)

    StuA, first discovered in Aspergillus nidulans and a member of the APSES class of transcription factors, regulates several essential developmental stages in fungi such as virulence, sporulation and toxin production in phytopathogenic fungi. Fusarium verticillioides (Fv), a maize phytopathogen, produ...

  19. ASPERGILLUS BOMBYCIS GENOTYPES (RFLP) FROM SILKWORM CULTIVATION

    Science.gov (United States)

    Eighteen isolates of Aspergillus bombycis from samples of dust, insect frass, and soil collected from 8 silkworm rearing facilities in Japan, as well as single silkworm rearing facilities in Indonesia and Malaysia, were subjected to DNA fingerprinting. PstI digests of total genomic DNA from each is...

  20. New applications for known drugs: Human glycogen synthase kinase 3 inhibitors as modulators of Aspergillus fumigatus growth.

    Science.gov (United States)

    Sebastián, Víctor; Manoli, Maria-Tsampika; Pérez, Daniel I; Gil, Carmen; Mellado, Emilia; Martínez, Ana; Espeso, Eduardo A; Campillo, Nuria E

    2016-06-30

    Invasive aspergillosis (IA) is one of the most severe forms of fungi infection. IA disease is mainly due to Aspergillus fumigatus, an air-borne opportunistic pathogen. Mortality rate caused by IA is still very high (50-95%), because of difficulty in early diagnostics and reduced antifungal treatment options, thus new and efficient drugs are necessary. The aim of this work is, using Aspergillus nidulans as non-pathogen model, to develop efficient drugs to treat IA. The recent discovered role of glycogen synthase kinase-3 homologue, GskA, in A. fumigatus human infection and our previous experience on human GSK-3 inhibitors focus our attention on this kinase as a target for the development of antifungal drugs. With the aim to identify effective inhibitors of colonial growth of A. fumigatus we use A. nidulans as an accurate model for in vivo and in silico studies. Several well-known human GSK-3β inhibitors were tested for inhibition of A. nidulans colony growth. Computational tools as docking studies and binding site prediction was used to explain the different biological profile of the tested inhibitors. Three of the five tested hGSK3β inhibitors are able to reduce completely the colonial growth by covalent bind to the enzyme. Therefore these compounds may be useful in different applications to eradicate IA. PMID:27131621

  1. Picosecond energy transfer in Porphyridium cruentum and Anacystis nidulans.

    OpenAIRE

    Brody, S. S.; Treadwell, C; Barber, J

    1981-01-01

    Picosecond energy transfer is measured in Anacystis nidulans and Porphyridium cruentum. Fluorescence is sensitized by a 6-ps laser flash, at 530 nm. The time dependence of fluorescence is measured with reference to the laser pulse. Fluorescence is recorded from phycoerythrin (576 nm), R-phycocyanin (640 nm), allophycocyanin (666 nm), Photosystem II chlorophyll (690 nm) and long wave length chlorophyll (715 nm). Energy transfer measurements are made at 37 degrees C, 23 degrees C, and 0 degrees...

  2. Aspergillus antigen skin test (image)

    Science.gov (United States)

    The aspergillus antigen skin test determines whether or not a person has been exposed to the mold aspergillus. It is performed by injecting an aspergillus antigen under the skin with a needle. After 48 ...

  3. Systems Analysis Unfolds the Relationship between the Phosphoketolase Pathway and Growth in Aspergillus nidulans

    DEFF Research Database (Denmark)

    Panagiotou, Gianni; Andersen, Mikael Rørdam; Grotkjær, Thomas;

    2008-01-01

    significantly affected by overexpression of the phk, while more than half of the affected genes were carbon source specific. During growth on glucose medium, the transcriptome analysis showed that the response to phk over-expression is targeted to neutralize the effect of the over-expression by regulating the...... on xylose, glycerol or ethanol as the sole carbon sources....

  4. Reducing fitness costs associated with antibiotic resistance: experimental evolution in the filamentous fungus Aspergillus nidulans

    OpenAIRE

    Schoustra, S.E.

    2004-01-01

    The 1990s saw the growth of two distinct strands of debates on the transformations and emerging problems besetting the urban space. One of these has focused on the relationship between globalisation and the similar changes metropolitan cities are undergoing, as they become home to numerous global economic agents such as multinational firms. According to it, globalisation can be understood as a worldwide reaching 'space of flows' - of money, information, and physical streams - emerging within ...

  5. Genetic and physical mapping of two centromere-proximal regions of chromosome IV in Aspergillus nidulans

    DEFF Research Database (Denmark)

    Aleksenko, Alexei Y.; Nielsen, Michael Lynge; Clutterbuck, A.J.

    2001-01-01

    revision of the genetic map of the chromosome, including the position of the centromere, Comparison of physical and genetic maps indicates that meiotic recombination is low in subcentromeric DNA, its frequency being reduced from 1 crossover per 0.8 Mb to approximately 1 crossover per 5 Mb per meiosis, The...

  6. Large-Scale Metabolomics Reveals A Complex Response of Aspergillus nidulans to Epigenetic Perturbation

    OpenAIRE

    Albright, Jessica C.; Henke, Matthew T.; Soukup, Alexandra A.; McClure, Ryan A.; Thomson, Regan J.; Keller, Nancy P.; Kelleher, Neil L.

    2015-01-01

    The microbial world offers a rich source of bioactive compounds for those able to sift through it. Technologies capable of quantitatively detecting natural products while simultaneously identifying known compounds would expedite the search for new pharmaceutical leads. Prior efforts have targeted histone deacetylases in fungi to globally activate the production of new secondary metabolites, yet no study has directly assessed its effects with minimal bias at the metabolomic level. Using untarg...

  7. Reducing fitness costs associated with antibiotic resistance: experimental evolution in the filamentous fungus Aspergillus nidulans

    NARCIS (Netherlands)

    Schoustra, S.E.

    2004-01-01

    The 1990s saw the growth of two distinct strands of debates on the transformations and emerging problems besetting the urban space. One of these has focused on the relationship between globalisation and the similar changes metropolitan cities are undergoing, as they become home to numerous global ec

  8. Aspergillus nidulans ArfB Plays a Role in Endocytosis and Polarized Growth ▿ †

    OpenAIRE

    Lee, Soo Chan; Schmidtke, Sabrina N.; Dangott, Lawrence J.; Shaw, Brian D.

    2008-01-01

    Filamentous fungi undergo polarized growth throughout most of their life cycles. The Spitzenkörper is an apical organelle composed primarily of vesicles that is unique to filamentous fungi and is likely to act as a vesicle supply center for tip growth. Vesicle assembly and trafficking are therefore important for hyphal growth. ADP ribosylation factors (Arfs), a group of small GTPase proteins, play an important role in nucleating vesicle assembly. Little is known about the role of Arfs in fila...

  9. Aspergillus spinal epidural abscess

    International Nuclear Information System (INIS)

    A spinal epidural abscess developed in a renal transplant recipient; results of a serum radioimmunoassay for Aspergillus antigen were positive. Laminectomy disclosed an abscess of the L4-5 interspace and L-5 vertebral body that contained hyphal forms and from which Aspergillus species was cultured. Serum Aspergillus antigen radioimmunoassay may be a valuable, specific early diagnostic test when systemic aspergillosis is a consideration in an immunosuppressed host

  10. Metabolomics of Aspergillus fumigatus

    DEFF Research Database (Denmark)

    Frisvad, Jens Christian; Rank, Christian; Nielsen, Kristian Fog; Larsen, Thomas Ostenfeld

    2009-01-01

    Aspergillus fumigatus is the most important species in Aspergillus causing infective lung diseases. This species has been reported to produce a large number of extrolites, including secondary metabolites, acids, and proteins such as hydrophobins and extracellular enzymes. At least 226 potentially...

  11. Diversity, molecular phylogeny and fingerprint profiles of airborne Aspergillus species using random amplified polymorphic DNA.

    Science.gov (United States)

    Kermani, Firoozeh; Shams-Ghahfarokhi, Masoomeh; Gholami-Shabani, Mohammadhassan; Razzaghi-Abyaneh, Mehdi

    2016-06-01

    In the present study, diversity and phylogenetic relationship of Aspergillus species isolated from Tehran air was studied using random amplified polymorphic DNA (RAPD)-polymerase chain reaction (RAPD-PCR). Thirty-eight Aspergillus isolates belonging to 12 species i.e. A. niger (28.94 %, 11 isolates), A. flavus (18.42 %, 7 isolates), A. tubingensis (13.15 %, 5 isolates), A. japonicus (10.52 %, 4 isolates), A. ochraceus (10.52 %, 4 isolates), and 2.63 %, 1 isolate from each A. nidulans, A. amstelodami, A. oryzae, A. terreus, A. versicolor, A. flavipes and A. fumigatus were obtained by settle plate method which they were distributed in 18 out of 22 sampling sites examined. Fungal DNA was extracted from cultured mycelia of all Aspergillus isolates on Sabouraud Dextrose Agar and used for amplification of gene fragments in RAPD-PCR using 11 primers. RAPD-PCR data was analyzed using UPGMA software. Resulting dendrogram of combined selected primers including PM1, OPW-04, OPW-05, P160, P54, P10 and OPA14 indicated the distribution of 12 Aspergillus species in 8 major clusters. The similarity coefficient of all 38 Aspergillus isolates ranged from 0.02 to 0.40 indicating a wide degree of similarities and differences within and between species. Taken together, our results showed that various Aspergillus species including some important human pathogenic ones exist in the outdoor air of Tehran by different extents in distribution and diversity and suggested inter- and intra-species genetic diversity among Aspergillus species by RAPD-PCR as a rapid, sensitive and reproducible method. PMID:27116962

  12. Restriction endonuclease analysis of Aspergillus fumigatus DNA.

    OpenAIRE

    Burnie, J P; Coke, A.; Matthews, R. C.

    1992-01-01

    AIMS: To develop a genome based DNA fingerprinting system for Aspergillus fumigatus mould. METHODS: DNA was extracted from 21 isolates obtained from eight patients with an aspergilloma. This was with a freeze-dried mycelial extract fragmented in liquid nitrogen. DNA was subsequently purified by phenol-chloroform extraction followed by ultracentrifugation on a caesium chloride gradient. The DNA was restricted by EcoRI and Xba I. RESULTS: All isolates were identical when cut by EcoRI; Xba I del...

  13. PHOTOSYNTHESIS ACTION SPECTRA IN ANACYSTIS NIDULANS AS DETERMINED BY PHOTOACOUSTIC SPECTROSCOPY

    OpenAIRE

    Carpentier, R.; LaRue, B; Leblanc, R.

    1983-01-01

    Acoustic data from Anacystis nidulans are used to obtain the action spectrum for photochemical energy storage. It is concluded that phycocyanin harvests light for both photoreactions but that chlorophyll a molecules convey most of their excitation energy to photoreaction I.

  14. Fine De Novo Sequencing of a Fungal Genome Using only SOLiD Short Read Data: Verification on Aspergillus oryzae RIB40

    OpenAIRE

    Myco Umemura; Yoshinori Koyama; Itaru Takeda; Hiroko Hagiwara; Tsutomu Ikegami; Hideaki Koike; Masayuki Machida

    2013-01-01

    The development of next-generation sequencing (NGS) technologies has dramatically increased the throughput, speed, and efficiency of genome sequencing. The short read data generated from NGS platforms, such as SOLiD and Illumina, are quite useful for mapping analysis. However, the SOLiD read data with lengths of

  15. Toward systems metabolic engineering of Aspergillus and Pichia species for the production of chemicals and biofuels

    DEFF Research Database (Denmark)

    Caspeta, Luis; Nielsen, Jens

    2013-01-01

    Recently genome sequence data have become available for Aspergillus and Pichia species of industrial interest. This has stimulated the use of systems biology approaches for large-scale analysis of the molecular and metabolic responses of Aspergillus and Pichia under defined conditions, which has...... resulted in much new biological information. Case-specific contextualization of this information has been performed using comparative and functional genomic tools. Genomics data are also the basis for constructing genome-scale metabolic models, and these models have helped in the contextualization of...... knowledge on the fundamental biology of Aspergillus and Pichia species. Furthermore, with the availability of these models, the engineering of Aspergillus and Pichia is moving from traditional approaches, such as random mutagenesis, to a systems metabolic engineering approach. Here we review the recent...

  16. (+)-Geodin from Aspergillus terreus

    DEFF Research Database (Denmark)

    Rønnest, Mads Holger; Nielsen, Morten Thrane; Leber, Blanka; Mortensen, Uffe Hasbro; Krämer, Alwin; Clausen, Mads Hartvig; Larsen, Thomas Ostenfeld; Harris, Pernille

    The fungal metabolite (+)-geodin [systematic name: (2R)-methyl 5,7-dichloro-4-hydroxy-6'-methoxy-6-methyl-3,4'-dioxospiro[benzofuran-2,1'-cyclohexa-2',5'-diene]-2'-carboxylate], C(17)H(12)Cl(2)O(7), was isolated from Aspergillus terreus. The crystal structure contains two independent molecules in...

  17. Optimization of glucose oxidase production by Aspergillus niger using genetic- and process-engineering techniques.

    Science.gov (United States)

    Hellmuth, K; Pluschkell, S; Jung, J K; Ruttkowski, E; Rinas, U

    1995-11-01

    Wild-type Aspergillus niger NRRL-3 was transformed with multiple copies of the glucose oxidase structural gene (god). The gene was placed under the control of the gpdA promoter of A. nidulans. For more efficient secretion the alpha-amylase signal peptide from A. oryzae was inserted in front of god. Compared to the wild type, the recombinant strain NRRL-3 (GOD3-18) produced up to four times more extracellular glucose oxidase under identical culture conditions. Addition of yeast extract (2 gl-1) to a mineral salts medium containing only glucose as carbon source increased volumetric and specific extracellular glucose oxidase activities by 130% and 50% respectively. With the same medium composition and inoculum size, volumetric and specific extracellular glucose oxidase activities increased more than ten times in bioreactor cultivations compared to shake-flask cultures. PMID:8590664

  18. New taxa in Aspergillus section Usti

    DEFF Research Database (Denmark)

    Samson, R. A.; Varga, J.; Meijer, M.;

    2011-01-01

    Based on phylogenetic analysis of sequence data, Aspergillus section Usti includes 21 species, inducing two teleomorphic species Aspergillus heterothallicus (=Emericella heterothallica) and Fennellia monodii. Aspergillus germanicus sp. nov. was isolated from indoor air in Germany. This species ha...

  19. Studies on Aspergillus flavus

    International Nuclear Information System (INIS)

    In vitro studies were conducted on conidia of Aspergillus flavus Link (aflatoxin producing) and Aspergillus flavus oryzae (non-toxigenic) strains isolated and identified in this laboratory. These strains differed in resistance to heat and gamma radiation, the toxigenic strain being more resistant to both treatments. Results of tests on dose-modifying factors indicated that composition, temperature and pH of suspending media affected radiation resistance. On the other hand, the size of the initial population and the age of the conidia did not influence the radiation resistance of either strain. Studies on thermal inactivation of the conidia suggested that the temperature employed was more important than the time of heat treatment. Conidia of both strains showed a synergistic effect of combined heat and radiation treatments, although a heat-radiation sequence was more effective than a radiation-heat sequence. (author)

  20. Identification of possible targets of the Aspergillus fumigatus CRZ1 homologue, CrzA

    Directory of Open Access Journals (Sweden)

    Goldman Gustavo H

    2010-01-01

    Full Text Available Abstract Background Calcineurin, a serine/threonine-specific protein phosphatase, plays an important role in the control of cell morphology and virulence in fungi. Calcineurin regulates localization and activity of a transcription factor called CRZ1. Recently, we characterize Aspergillus fumigatus CRZ1 homologue, AfCrzA. Here, we investigate which pathways are influenced by A. fumigatus AfCrzA during a short pulse of calcium by comparatively determining the transcriptional profile of A. fumigatus wild type and ΔAfcrzA mutant strains. Results We were able to observe 3,622 genes modulated in at least one timepoint in the mutant when compared to the wild type strain (3,211 and 411 at 10 and 30 minutes, respectively. Decreased mRNA abundance in the ΔcrzA was seen for genes encoding calcium transporters, transcription factors and genes that could be directly or indirectly involved in calcium metabolism. Increased mRNA accumulation was observed for some genes encoding proteins involved in stress response. AfCrzA overexpression in A. fumigatus increases the expression of several of these genes. The deleted strain of one of these genes, AfRcnA, belonging to a class of endogenous calcineurin regulators, calcipressins, had more calcineurin activity after exposure to calcium and was less sensitive to menadione 30 μM, hydrogen peroxide 2.5 mM, EGTA 25 mM, and MnCl2 25 mM. We constructed deletion, overexpression, and GFP fusion protein for the closely related A. nidulans AnRcnA. GFP::RcnA was mostly detected along the germling, did not accumulate in the nuclei and its location is not affected by the cellular response to calcium chloride. Conclusion We have performed a transcriptional profiling analysis of the A. fumigatus ΔAfcrzA mutant strain exposed to calcium stress. This provided an excellent opportunity to identify genes and pathways that are under the influence of AfCrzA. AfRcnA, one of these selected genes, encodes a modulator of calcineurin

  1. Pituitary aspergillus infection.

    Science.gov (United States)

    Moore, Lauren A; Erstine, Emily M; Prayson, Richard A

    2016-07-01

    Fungal infection should be considered in the differential diagnosis of a pituitary or sellar mass, albeit fungal infections involving the pituitary gland and sella are a rare occurrence. We report a case of Aspergillus infection involving the pituitary gland and sellar region discovered in a 74-year-old man. The patient had a history of hypertension, chronic renal disease, autoimmune hemolytic anemia and presented with right eye pain, headaches and worsening hemiparesis. Imaging studies revealed a right internal carotid artery occlusion and an acute right pontine stroke along with smaller infarcts in the right middle cerebral artery distribution. Clinically, the patient was thought to have vasculitis. An infectious etiology was not identified. He developed respiratory distress and died. At autopsy, necrotizing meningitis was discovered. A predominantly chronic inflammatory cell infiltrate consisting of benign-appearing lymphocytes, plasma cells and macrophages was accompanied by acute angle branching, angioinvasive hyphae which were highlighted on Gomori methenamine silver staining and were morphologically consistent with Aspergillus species. In previously reported cases of Aspergillus infection involving the pituitary or sella, most presented with headaches or impaired vision and were not immunocompromised. A transsphenoidal surgical approach is recommended in suspected cases in order to minimize the risk of dissemination of the infection. Some patients have responded well to antifungal medications once diagnosed. PMID:26896907

  2. Diversity and specificity of microsatellites within Aspergillus section Fumigati

    Directory of Open Access Journals (Sweden)

    Araujo Ricardo

    2012-07-01

    Full Text Available Abstract Background Microsatellites (or short tandem repeats, STRs are the genetic markers of choice for studying Aspergillus fumigatus molecular epidemiology due to its reproducibility and high discrimination power. However, the specificity of these markers must be investigated in a group of isolates from closely related species. The aim of this work was to test a microsatellite-based PCR multiplex previously designed for A. fumigatus in a set of species belonging to section Fumigati, namely Aspergillus fumigatiaffinis, Aspergillus lentulus, Aspergillus novofumigatus, Aspergillus unilateralis, Aspergillus viridinutans, Neosartorya fischeri, Neosartorya hiratsukae, Neosartorya pseudofischeri and Neosartorya udagawae. Results The reference A. fumigatus strain ATCC 46645 was easily genotyped in standard conditions showing a final electrophoretic profile of 8 expected peaks corresponding to each microsatellite locus. Inversely, no peaks were observed for all other species from section Fumigati, with an exception for marker MC6b in A. unilateralis. By screening the genome sequence of Neosartorya fischeri NRRL 181, the results showed that MC3, MC6a and MC7 might be employed for N. fischeri genotyping since these markers present several repeats of each motif. The accumulation of insertions and deletions was frequently observed in the genomic regions surrounding the microsatellites, including those where the A. fumigatus primers are located. The amplification of microsatellite markers in less stringent amplification conditions resulted in a distinct electrophoretic profile for species within section Fumigati. Conclusions Therefore, the microsatellite-based PCR multiplex allow simple identification of A. fumigatus and, with a slight modification of temperature conditions, it also allows discriminating other pathogenic species within section Fumigati, particularly A. fumigatiaffinis, N. fischeri and N. udagawae.

  3. Aspergillus flavus VelB acts distinctly from VeA in conidiation and may coordinate with FluG to modulate sclerotial production.

    Science.gov (United States)

    Chang, Perng-Kuang; Scharfenstein, Leslie L; Li, Ping; Ehrlich, Kenneth C

    2013-01-01

    The proteins VeA, VelB and LaeA of Aspergillus nidulans form a heterotrimeric complex (the velvet complex) in the dark to coordinate sexual development and production of some secondary metabolites. VeA and VelB of A. nidulans and Aspergillus fumigatus also are repressors of conidiation, but VeA of Aspergillus flavus in studied strains acts positively on conidiation. In the present study, we show via yeast-two hybrid assays that interactions among A. flavus VeA, VelB, and LaeA are conserved as in the A. nidulans velvet complex. We found that FluG, which is required for conidiophore formation in A. nidulans but whose deletion in A. flavus delays onset of conidiation, was probably an interacting partner of VelB. Deletion of velB in A. flavus CA14 severely impaired conidiation in the dark although to a lesser extent than deletion of veA. In both mutants fluG deletion resulted in further decreased conidiation even in the light. Deletion of fluG in the ΔlaeA strain, however, did not affect conidiation. All mutant types were unable to produce aflatoxin and sclerotia. Cross-complementation of the ΔvelB strain with gpdA::veA restored conidiation but not aflatoxin production although aflR, the aflatoxin pathway regulatory gene, was expressed at a normal level. Cross-complementation of the ΔveA strain with gpdA::velB failed to restore conidiation and aflatoxin production. The ΔvelB strain complemented with or a wild type transformed by gpdA::velB had elevated sclerotial production as the ΔfluG strain. Concerted interactions of A. flavus VeA and VelB with LaeA are critical for conidiation and aflatoxin biosynthesis. VelB may have a dual role and likely coordinates with FluG to modulate sclerotial production. PMID:23994319

  4. In vitro susceptibility testing of Aspergillus spp. against voriconazole, itraconazole, posaconazole, amphotericin B and caspofungin

    Institute of Scientific and Technical Information of China (English)

    SHI Jun-yan; WANG He; GUO Li-na; XU Ying-chun; SHI Yi; L(U) Huo-xiang; LIU Yong; ZHAO Wang-sheng; CHEN Dong-mei; XI Li-yan; ZHOU Xin

    2010-01-01

    Background During recent years, the incidence of serious infections caused by opportunistic fungi has increased dramatically due to alterations of the immune status of patients with hematological diseases, malignant tumors,transplantations and so forth. Unfortunately, the wide use of triazole antifungal agents to treat these infections has lead to the emergence of Aspergillus spp. resistant to triazoles. The present study was to assess the in vitro activities of five antifungal agents (voriconazole, itraconazole, posaconazole, amphotericin B and caspofungin) against different kinds of Aspergillus spp. that are commonly encountered in the clinical setting.Methods The agar-based Etest MIC method was employed. One hundred and seven strains of Aspergillus spp. (5 species) were collected and prepared according to Etest Technique Manuel. Etest MICs were determined with RPMI agar containing 2% glucose and were read after incubation for 48 hours at 35℃. MIC50, MIC90 and MIC range were acquired by Whonet 5.4 software.Results The MIC90 of caspofungin against A. fumigatus, A. flavus and A. nidulans was 0.094 μg/ml whereas the MIC90 against A. niger was 0.19 μg/ml. For these four species, the MlC90 of caspofungin was the lowest among the five antifungal agents. For A. terrus, the MIC90 of posaconazole was the lowest. For A. fumigatus and A. flavus, the MlC90in order of increasing was caspofungin, posaconazole, voriconazole, itraconazole, and amphotericin B. The MIC of amphotericin B against A. terrus was higher than 32 μg/ml in all 7 strains tested.Conclusions The in vitro antifungal susceptibility test shows the new drug caspofungin, which is a kind of echinocandins, has good activity against the five species of Aspergillus spp. and all the triazoles tested have better in vitro activity than traditional amphotericin B.

  5. An Aspergillus nidulans bZIP response pathway hardwired for defensive secondary metabolism operates through aflR

    OpenAIRE

    Yin, Wenbing; Amaike, Saori; Wohlbach, Dana J.; Gasch, Audrey P.; Chiang, Yi-Ming; Wang, Clay C.; Bok, JinWoo; Rohlfs, Marko; Keller, Nancy P

    2012-01-01

    The eukaryotic bZIP transcription factors are critical players in organismal response to environmental challenges. In fungi, the production of secondary metabolites (SMs) is hypothesized as one of the responses to environmental insults, e.g. attack by fungivorous insects, yet little data to support this hypothesis exists. Here we establish a mechanism of bZIP regulation of SMs through RsmA, a recently discovered YAP-like bZIP protein. RsmA greatly increases SM production by binding to two sit...

  6. Aspergillus nidulans as a platform for discovery and characterization of complex biosynthetic pathways

    DEFF Research Database (Denmark)

    Anyaogu, Diana Chinyere

    Filamentous fungi produce a wide range of bioactive compounds, classified as secondary metabolites,which have the potential to be used as pharmaceuticals, insecticides, fungicides and food additives.Secondary metabolites also include mycotoxins, which are produced by fungi that contaminate food...

  7. Aspergillus nidulans α-galactosidase of glycoside hydrolase family 36 catalyses the formation of α-galacto-oligosaccharides by transglycosylation

    DEFF Research Database (Denmark)

    Nakai, Hiroyuki; Baumann, Martin; Petersen, B. O.;

    2010-01-01

    transglycosylate monosaccharides without the 6-hydroxymethyl group, i.e. xylose, l-arabinose, l-fucose and l-rhamnose, or with axial 3-OH, i.e. gulose, allose, altrose and l-rhamnose. Structural modelling using Thermotoga maritima GH36 α-galactosidase as the template and superimposition of melibiose from the...

  8. Aspergillus saccharolyticus sp. nov., a new black Aspergillus species isolated in Denmark

    DEFF Research Database (Denmark)

    Sørensen, Annette; Lübeck, Peter S.; Lübeck, Mette; Nielsen, Kristian Fog; Ahring, Birgitte K.; Teller, Philip J.; Frisvad, Jens Christian

    2011-01-01

    A novel species, Aspergillus saccharolyticus sp. nov., belonging to the Aspergillus section Nigri group is described. This species was isolated in Denmark from treated hardwood. Its taxonomic status was determined using a polyphasic taxonomic approach including phenotypic (morphology and extrolite...... Aspergillus species that is morphologically similar to Aspergillus japonicus and Aspergillus aculeatus, but has a totally different extrolite profile compared to any known Aspergillus species. The type strain of A. saccharolyticus sp. nov. is CBS 127449T ( = IBT 28509T)....

  9. Aspergillus-Related Lung Disease

    Directory of Open Access Journals (Sweden)

    Alia Al-Alawi

    2005-01-01

    Full Text Available Aspergillus is a ubiquitous dimorphic fungus that causes a variety of human diseases ranging in severity from trivial to life-threatening, depending on the host response. An intact host defence is important to prevent disease, but individuals with pre-existing structural lung disease, atopy, occupational exposure or impaired immunity are susceptible. Three distinctive patterns of aspergillus-related lung disease are recognized: saprophytic infestation of airways, cavities and necrotic tissue; allergic disease including extrinsic allergic alveolitis, asthma, allergic bronchopulmonary aspergillosis, bronchocentric granulomatosis and chronic eosinophilic pneumonia; and airway and tissue invasive disease -- pseudomembranous tracheobronchitis, acute bronchopneumonia, angioinvasive aspergillosis, chronic necrotizing aspergillosis and invasive pleural disease. A broad knowledge of these clinical presentations and a high index of suspicion are required to ensure timely diagnosis and treatment of the potentially lethal manifestations of aspergillus-related pulmonary disease. In the present report, the clinical, radiographic and pathological aspects of the various aspergillus-related lung diseases are briefly reviewed.

  10. Aspergillus fumigatus in Poultry

    Directory of Open Access Journals (Sweden)

    Pascal Arné

    2011-01-01

    Full Text Available Aspergillus fumigatus remains a major respiratory pathogen in birds. In poultry, infection by A. fumigatus may induce significant economic losses particularly in turkey production. A. fumigatus develops and sporulates easily in poor quality bedding or contaminated feedstuffs in indoor farm environments. Inadequate ventilation and dusty conditions increase the risk of bird exposure to aerosolized spores. Acute cases are seen in young animals following inhalation of spores, causing high morbidity and mortality. The chronic form affects older birds and looks more sporadic. The respiratory tract is the primary site of A. fumigatus development leading to severe respiratory distress and associated granulomatous airsacculitis and pneumonia. Treatments for infected poultry are nonexistent; therefore, prevention is the only way to protect poultry. Development of avian models of aspergillosis may improve our understanding of its pathogenesis, which remains poorly understood.

  11. Update on antifungal drug resistance mechanisms of Aspergillus fumigatus.

    Science.gov (United States)

    Chamilos, G; Kontoyiannis, D P

    2005-12-01

    Although the arsenal of agents with anti-Aspergillus activity has expanded over the last decade, mortality due to invasive aspergillosis (IA) remains unacceptably high. Aspergillus fumigatus still accounts for the majority of cases of IA; however less susceptible to antifungals non-fumigatus aspergilli began to emerge. Antifungal drug resistance of Aspergillus might partially account for treatment failures. Recent advances in our understanding of mechanisms of antifungal drug action in Aspergillus, along with the standardization of in vitro susceptibility testing methods, has brought resistance testing to the forefront of clinical mycology. In addition, molecular biology has started to shed light on the mechanisms of resistance of A. fumigatus to azoles and the echinocandins, while genome-based assays show promise for high-throughput screening for genotypic antifungal resistance. Several problems remain, however, in the study of this complex area. Large multicenter clinical studies--point prevalence or longitudinal--to capture the incidence and prevalence of antifungal resistance in A. fumigatus isolates are lacking. Correlation of in vitro susceptibility with clinical outcome and susceptibility breakpoints has not been established. In addition, the issue of cross-resistance between the newer triazoles is of concern. Furthermore, in vitro resistance testing for polyenes and echinocandins is difficult, and their mechanisms of resistance are largely unknown. This review examines challenges in the diagnosis, epidemiology, and mechanisms of antifungal drug resistance in A. fumigatus. PMID:16488654

  12. Repair of X-ray induced ruptures in DNA of blue-green alga Anacystis nidulans

    International Nuclear Information System (INIS)

    The work deals with systems of repair of radiation damage in the DNA of the blue-green alga Anacystis nidulans by the modified method of DNA fractionation by molecular weight with centrifuging in an alkaline sucrose gradient. It is shown that effective post-radiation repair of X-ray-induced breaks in DNA in A. nidulans cells takes place only after irradiation in a tris-HCl buffer at 200C. It is assumed that the system of restoration in actively metabolizing cells is similar to the mechanism of ''slow'' repair, which is responsible for repair synthesis and the elimination of the gaps formed during excision or post-replicative repair. On the basis of the differences found in the DNA sedimentation profiles immediately after irradiation of cells at 00 or 200 in a tris-HCl or a cerium buffer, the authors conclude that A. nidulans cells also have ''rapid'' repair systems which operate right in the irradiation period and resotre the single-strand breaks in DNA. Irradiation in a cerium buffer or at low temperature inhibited both the ''rapid'' and the ''slow'' repair of breaks in DNA. (V.A.P.)

  13. The complete nucleotide sequence of a 16S ribosomal RNA gene from a blue-green alga, Anacystis nidulans.

    Science.gov (United States)

    Tomioka, N; Sugiura, M

    1983-01-01

    The complete nucleotide sequence of a 16S ribosomal RNA gene from a blue-green alga, Anacystis nidulans, has been determined. Its coding region is estimated to be 1,487 base pairs long, which is nearly identical to those reported for chloroplast 16S rRNA genes and is about 4% shorter than that of the Escherichia coli gene. The 16S rRNA sequence of A. nidulans has 83% homology with that of tobacco chloroplast and 74% homology with that of E. coli. Possible stem and loop structures of A. nidulans 16S rRNA sequences resemble more closely those of chloroplast 16S rRNAs than those of E. coli 16S rRNA. These observations support the endosymbiotic theory of chloroplast origin. PMID:6412038

  14. Aspergillus flavus Blast2GO gene ontology database: elevated growth temperature alters amino acid metabolism

    Science.gov (United States)

    The availability of a representative gene ontology (GO) database is a prerequisite for a successful functional genomics study. Using online Blast2GO resources we constructed a GO database of Aspergillus flavus. Of the predicted total 13,485 A. flavus genes 8,987 were annotated with GO terms. The mea...

  15. Comparative chemistry of Aspergillus oryzae (RIB40) and A. flavus (NRRL 3357)

    DEFF Research Database (Denmark)

    Rank, Christian; Klejnstrup, Marie Louise; Petersen, Lene Maj;

    2012-01-01

    Aspergillus oryzae and A. flavus are important species in industrial biotechnology and food safety and have been some of the first aspergilli to be fully genome sequenced. Bioinformatic analysis has revealed 99.5% gene homology between the two species pointing towards a large coherence in the...

  16. The molecular and genetic basis of conidial pigmentation in Aspergillus niger

    DEFF Research Database (Denmark)

    Jørgensen, Thomas R.; Park, Joohae; Arentshorst, Mark;

    2011-01-01

    A characteristic hallmark of Aspergillus niger is the formation of black conidiospores. We have identified four loci involved in spore pigmentation of A. niger by using a combined genomic and classical complementation approach. First, we characterized a newly isolated color mutant, colA, which la...

  17. The chemical heritage of Aspergillus flavus in A. oryzae RIB 40

    DEFF Research Database (Denmark)

    Rank, Christian; Klejnstrup, Marie Louise; Petersen, Lene Maj; Frisvad, Jens Christian; Larsen, Thomas Ostenfeld

    Aspergillus oryzae is a very important species in biotechnology and has been used for centuries in traditional Asian fermentation. The RIB40 strain is particularly interesting as it was one of the first genome sequenced Aspergilli together with A. flavus, a prominent food and feed contaminant...... with indications to specific genetic changes. Several new metabolites and changes in biosynthetic routes have been found in A. oryzae, indicating subtle changes in the genomic heritage from A. flavus....

  18. 76 FR 16297 - Aspergillus flavus

    Science.gov (United States)

    2011-03-23

    ... exemptions for experimental use of Aspergillus flavus AF36 on pistachio (72 FR 28871, May 23, 2007) (FRL-8129... Findings In the Federal Register of March 3, 2010 (75 FR 9596) (FRL-8811-2), EPA issued a notice pursuant..., 2003 (68 FR 41541) (FRL-7311-6). Those health effects data were the basis for establishing...

  19. Aspergillus infections in cystic fibrosis.

    Science.gov (United States)

    King, Jill; Brunel, Shan F; Warris, Adilia

    2016-07-01

    Patients with cystic fibrosis (CF) suffer from chronic lung infection and airway inflammation. Respiratory failure secondary to chronic or recurrent infection remains the commonest cause of death and accounts for over 90% of mortality. Bacteria as Staphylococcus aureus, Pseudomonas aeruginosa and Burkholderia cepacia complex have been regarded the main CF pathogens and their role in progressive lung decline has been studied extensively. Little attention has been paid to the role of Aspergillus spp. and other filamentous fungi in the pathogenesis of non-ABPA (allergic bronchopulmonary aspergillosis) respiratory disease in CF, despite their frequent recovery in respiratory samples. It has become more apparent however, that Aspergillus spp. may play an important role in chronic lung disease in CF. Research delineating the underlying mechanisms of Aspergillus persistence and infection in the CF lung and its link to lung deterioration is lacking. This review summarizes the Aspergillus disease phenotypes observed in CF, discusses the role of CFTR (cystic fibrosis transmembrane conductance regulator)-protein in innate immune responses and new treatment modalities. PMID:27177733

  20. Aspergillus mediastinitis after cardiac surgery

    Directory of Open Access Journals (Sweden)

    Marie-Josée Caballero

    2016-03-01

    Conclusion: The clinical features of postoperative Aspergillus mediastinitis may be paucisymptomatic, emphasizing the need for a low index of suspicion in cases of culture-negative mediastinitis or in indolent wound infections. In addition to surgical debridement, the central component of antifungal therapy should include amphotericin B or voriconazole.

  1. Induction of mutations in blue-green alga Anacystis nidulans by consolidated and split UV irradiation

    International Nuclear Information System (INIS)

    Ultraviolet mutability of consolidated and split dose treatment in A. nidulans was investigated with reference to induction of phage- and streptomycin-resistant markers. The consolidated UV treatment induced both the markers about 100-150-fold, whereas under photoreactivating conditions the survival of alga was enhanced and mutation frequency was decreased. The split UV treatment with 6 hr dark incubation between two UV exposures enhanced the survival and mutation frequencies to 500-700 fold above the back-ground level. The data give indirect evidence for the presence of error-prone dark repair system in this organism. (auth.)

  2. Transcriptional organization of the phycocyanin subunit gene clusters of the cyanobacterium Anacystis nidulans UTEX 625.

    OpenAIRE

    Kalla, S R; Lind, L K; Lidholm, J; Gustafsson, P

    1988-01-01

    The phycocyanin subunit gene cluster is duplicated on the chromosome of the cyanobacterium Anacystis nidulans UTEX 625. The two gene clusters cpcB1A1 (left) and cpcB2A2 (right) are separated by about 2,500 base pairs, and in each cluster the beta-subunit gene is located upstream from the alpha-subunit gene. Filter hybridizations with phycocyanin-specific probes to total RNA detected at least two major transcripts that were 1,300 to 1,400 nucleotides long. Besides these major mRNA species, two...

  3. Identification of thermostable beta-xylosidase activities produced by Aspergillus brasiliensis and Aspergillus niger

    DEFF Research Database (Denmark)

    Pedersen, Mads; Lauritzen, H.K.; Frisvad, Jens Christian; Meyer, Anne S.

    2007-01-01

    Twenty Aspergillus strains were evaluated for production of extracellular cellulolytic and xylanolytic activities. Aspergillus brasiliensis, A. niger and A. japonicus produced the highest xylanase activities with the A. brasiliensis and A. niger strains producing thermostable beta-xylosidases. The...

  4. Identification of thermostable β-xylosidase activities produced by Aspergillus brasiliensis and Aspergillus niger

    DEFF Research Database (Denmark)

    Pedersen, Mads; Lauritzen, Henrik Klitgaard; Frisvad, Jens Christian; Meyer, Anne Boye Strunge

    2007-01-01

    Twenty Aspergillus strains were evaluated for production of extracellular cellulolytic and xylanolytic activities. Aspergillus brasiliensis, A. niger and A. japonicus produced the highest xylanase activities with the A. brasiliensis and A. niger strains producing thermostable beta-xylosidases. The...

  5. DNA apophotolyase from Anacystis nidulans: 1.8 A structure, 8-HDF reconstitution and X-ray-induced FAD reduction.

    NARCIS (Netherlands)

    R. Kort; H. Komori; S. Adachi; K. Miki; A. Eker

    2004-01-01

    DNA photolyase is a unique flavoenzyme that repairs UV-induced DNA lesions using the energy of visible light. Anacystis nidulans photolyase contains a light-harvesting chromophore, 8-hydroxy-5-deazaflavin (8-HDF), and flavin adenine dinucleotide (FAD) which, in contrast to the 8-HDF chromophore, is

  6. Cloning of a third nitrate reductase gene from the cyanobacterium Anacystis nidulans R2 using a shuttle cosmid library

    NARCIS (Netherlands)

    Kuhlemeier, C.J.; Teeuwsen, V.J.P.; Janssen, M.J.T.; Arkel, G.A. van

    1984-01-01

    A strategy for gene cloning in the cyanobacterium Anacystis nidulans R2 was developed which made use of a gene library constructed in a shuttle cosmid vector. The method involved phenotypic complementation of mutants with pooled cosmid DNA. The development of the procedure and its application to the

  7. Ochratoxin A-Produktion durch Aspergillus ochraceus

    OpenAIRE

    Mühlencoert, Ellen

    2006-01-01

    Ochratoxin A, one of the 5 most important mycotoxins in food safety, is produced by several Aspergillus and Penicillium strains growing on grain, grapes and coffee. OTA biosynthesis in Aspergillus spp. depends more on the complex interaction of diverse environmental conditions than on a single growth factor or even the genetic ability to produce OTA. No apparent connection between biomass and OTA production was observed. OTA production by Aspergillus ochraceus could be controlled by the pH of...

  8. Developmental regulators in Aspergillus fumigatus.

    Science.gov (United States)

    Park, Hee-Soo; Yu, Jae-Hyuk

    2016-03-01

    The filamentous fungus Aspergillus fumigatus is the most prevalent airborne fungal pathogen causing severe and usually fatal invasive aspergillosis in immunocompromised patients. This fungus produces a large number of small hydrophobic asexual spores called conidia as the primary means of reproduction, cell survival, propagation, and infectivity. The initiation, progression, and completion of asexual development (conidiation) is controlled by various regulators that govern expression of thousands of genes associated with formation of the asexual developmental structure conidiophore, and biogenesis of conidia. In this review, we summarize key regulators that directly or indirectly govern conidiation in this important pathogenic fungus. Better understanding these developmental regulators may provide insights into the improvement in controlling both beneficial and detrimental aspects of various Aspergillus species. PMID:26920882

  9. Regulatory processes in Aspergillus niger

    DEFF Research Database (Denmark)

    Poulsen, Lars

    Filamentous fungi are extensively used in the fermentation industry for synthesis of numerous products. One of the most important, is the fungus Aspergillus niger, used industrially for production of organic acids, and homologous as well as heterologous enzymes. This fungus has numerous of advant...... fumonisin production, identified. These formed the basis for the subsequent examinations, which resulted in the identification of azelaic acid, a plant hormone and a very potent fumonisin inducer....

  10. Germination of Aspergillus niger conidia

    OpenAIRE

    Hayer, Kimran

    2014-01-01

    Aspergillus niger is a black-spored filamentous fungus that forms asexual spores called conidospores (‘conidia’). Germination of conidia, leading to the formation of hyphae, is initiated by conidial swelling and mobilisation of endogenous carbon and energy stores, followed by polarisation and emergence of a hyphal germ tube. These morphological and biochemical changes which define the model of germination have been studied with the aim of understanding how conidia sense and utilise different...

  11. The Volatome of Aspergillus fumigatus

    OpenAIRE

    Heddergott, C.; Calvo, A. M.; Latgé, J P

    2014-01-01

    Early detection of invasive aspergillosis is absolutely required for efficient therapy of this fungal infection. The identification of fungal volatiles in patient breath can be an alternative for the detection of Aspergillus fumigatus that still remains problematic. In this work, we investigated the production of volatile organic compounds (VOCs) by A. fumigatus in vitro, and we show that volatile production depends on the nutritional environment. A. fumigatus produces a multiplicity of VO...

  12. High abundance of Serine/Threonine-rich regions predicted to be hyper-O-glycosylated in the secretory proteins coded by eight fungal genomes

    Directory of Open Access Journals (Sweden)

    González Mario

    2012-09-01

    Full Text Available Abstract Background O-glycosylation of secretory proteins has been found to be an important factor in fungal biology and virulence. It consists in the addition of short glycosidic chains to Ser or Thr residues in the protein backbone via O-glycosidic bonds. Secretory proteins in fungi frequently display Ser/Thr rich regions that could be sites of extensive O-glycosylation. We have analyzed in silico the complete sets of putatively secretory proteins coded by eight fungal genomes (Botrytis cinerea, Magnaporthe grisea, Sclerotinia sclerotiorum, Ustilago maydis, Aspergillus nidulans, Neurospora crassa, Trichoderma reesei, and Saccharomyces cerevisiae in search of Ser/Thr-rich regions as well as regions predicted to be highly O-glycosylated by NetOGlyc (http://www.cbs.dtu.dk. Results By comparison with experimental data, NetOGlyc was found to overestimate the number of O-glycosylation sites in fungi by a factor of 1.5, but to be quite reliable in the prediction of highly O-glycosylated regions. About half of secretory proteins have at least one Ser/Thr-rich region, with a Ser/Thr content of at least 40% over an average length of 40 amino acids. Most secretory proteins in filamentous fungi were predicted to be O-glycosylated, sometimes in dozens or even hundreds of sites. Residues predicted to be O-glycosylated have a tendency to be grouped together forming hyper-O-glycosylated regions of varying length. Conclusions About one fourth of secretory fungal proteins were predicted to have at least one hyper-O-glycosylated region, which consists of 45 amino acids on average and displays at least one O-glycosylated Ser or Thr every four residues. These putative highly O-glycosylated regions can be found anywhere along the proteins but have a slight tendency to be at either one of the two ends.

  13. Identification of Two Different 14-α Sterol Demethylase-Related Genes (cyp51A and cyp51B) in Aspergillus fumigatus and Other Aspergillus Species

    OpenAIRE

    Mellado, E.; Diaz-Guerra, T. M.; Cuenca-Estrella, M.; Rodriguez-Tudela, J. L.

    2001-01-01

    Two cyp51-related genes (cyp51A and cyp51B) encoding 14-α sterol demethylase-like enzymes were identified in the opportunistic human pathogen Aspergillus fumigatus. PCR amplification using degenerate oligonucleotides based on conserved areas of cytochrome P450 demethylases of other filamentous fungi and yeasts allowed the cloning and sequencing of two different homologue genes in A. fumigatus. Southern analysis confirmed that both genes hybridized to distinct genomic loci and that both are re...

  14. Liver injury in invasive aspergillus. Echographic findings

    International Nuclear Information System (INIS)

    Aspergillus is the second most common mycoses in immuno compromised patients. The invasive form is associated with a mortality of approximately 100%. We present a case of invasive aspergillus in a heart transplant recipient in whom ultrasound disclosed the presence of liver injury which was later confirmed by necropsy. We review the available literature. (Author) 15 refs

  15. Identification of a classical mutant in the industrial host Aspergillus niger by systems genetics: LaeA is required for citric acid production and regulates the formation of some secondary metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jing; Arentshorst, Mark; Nair, Deepa; Dai, Ziyu; Baker, Scott E.; Frisvad, Jens; Nielsen, Kristian F.; Punt, Peter J.; Ram, Arthur F.

    2016-01-11

    Rapid acidification of the culture medium by the production of organic acids and the production of acid-induced proteases are key characteristics of the filamentous fungus Aspergillus niger. The D15 mutant of A. niger is non-acidifying mutant and used often for the expression of recombinant proteins in A. niger, because of its reduced production of extracellular proteases under non-acidic conditions. In this study, the D15 mutant is characterized in detail. Strongly reduced levels of citric and oxalic acid were observed in the D15 mutant both in shake flask cultures and in controlled batch cultivations. To identify the mutation in the D15 mutant, we successfully combined high-throughput sequencing (Illumina) with bulk segregant analysis. Because of the lack of a sexual cycle for A. niger, the parasexual cycle was used to generate a pool of segregants. From the 52 single nucleotide polymorphisms (SNPs) between the parental strains, three SNPs were homozygous in the genomic DNA of pool of segregants. These three SNPs mapped to all the right arm of chromosome II, indicating that this region contains the genetic locus affecting the phenotype related to acid production. Of the three SNPs, one mutation resulted in a missense mutation in the gene encoding the A. niger homologue of the A. nidulans methyltransferase gene laeA. Complementation analysis of the original mutant with the laeA gene and targeted disruption of laeA further confirmed that LaeA is involved in citric acid production in A. niger lab (N402) and citric acid production strains (ATCC 11414). Analysis of the secondary metabolite (SM) profile of the laeA mutants indicate that LaeA is required for the production of several SMs (asperrubrol, atromentin and JBIR86), but deletion of laeA also resulted in the presence of SMs (aspernigrin A/B and BMS-192548) that were not detected in the wild-type strain. The levels of ten other SMs were not strongly affected as a result of laeA deletion indicating that only a

  16. Two novel species of Aspergillus section Nigri from indoor air

    Science.gov (United States)

    Aspergillus collinsii, Aspergillus floridensis, and Aspergillus trinidadensis are described as novel uniseriate species of Aspergillus section Nigri isolated from air samples. To describe the species we used phenotypes from 7-d Czapek yeast extract agar culture (CYA) and malt extract agar culture (M...

  17. CO{sub 2}-removal characteristics of Anacystis nidulans R2 in airlift bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, H.; Ohkuni, N.; Kajiwara, S.; Ohtaguchi, K. [Tokyo Institute of Technology, Tokyo (Japan). Dept. of Chemical Engineering

    1997-02-01

    The cyanobacterium Anocystis nidulans R2 is a photosynthetic procaryote grown only under inorganic carbon conditions. The authors studied cell-growth (CO{sub 2}-removal) characteristics of this strain, cultivated photoautotrophically at 30{degree}C in 1.1. dm{sup 3} in airlift bioreactors. The highest growth rate of 0.046 h{sup -1} was achieved when the culture was illuminated at 8 klx and sparged with 5% CO{sub 2} (volume/volume). But, the level of attainable cell mass concentration was not greatly affected by the CO{sub 2} concentration between 5% and 30%. These results are suggestive of an opportunity to integrate this bioreactor as a technique for direct CO{sub 2} removal from boiler flue gas. 16 refs., 3 figs., 1 tab.

  18. Aspergillus Osteomyelitis of the Skull.

    Science.gov (United States)

    Nicholson, Simon; King, Richard; Chumas, Paul; Russell, John; Liddington, Mark

    2016-07-01

    Osteomyelitis of the craniofacial skeleton is rare, with fungal pathogens least commonly implicated. The authors present 2 patients of osteomyelitis of the skull caused by Aspergillus spp. and discuss the diagnosis, clinicopathological course, and management strategies.Late recurrence seen in this type of infection warrants long-term follow-up and a high index of suspicion for the clinical signs associated with recurrence.Such patients would benefit from their surgical debridement being planned and managed via a specialist craniofacial unit, so as to utilize the most aesthetically sensitive approach and the experience of specialists from several surgical disciplines. PMID:27391523

  19. Ribonuclease Production by Aspergillus species

    OpenAIRE

    Eleni Gomes; Roberto da Silva; Alcides Serzedello

    1998-01-01

    Ribonuclease production by Aspergillus flavipes, A. sulphureus and A. fischeri in semi-synthetic medium, after 24-144 hours at 30ºC under shaking, was studied. After cultivation, the medium was separated from micelia by filtration and the resultant solution was used as enzymatic extract. The highest amount of biomass and RNase was obtained after 96 hours of cultivation. The enzymes produced by three species presented similar characteristics, with optimum temperature at 55ºC and two peaks of a...

  20. Two novel, putatively cell wall-associated and glycosylphosphatidylinositol-anchored alpha-glucanotransferase enzymes of aspergillus niger

    NARCIS (Netherlands)

    van der Kaaij, R. A.; Yuan, X.-L.; Franken, A.; Ram, A. F. J.; Punt, P. J.; Dijkhuizen, L.; Maarel, M.J.E.C. van der

    2007-01-01

    In the genome sequence of Aspergillus niger CBS 513.88, three genes were identified with high similarity to fungal alpha-amylases. The protein sequences derived from these genes were different in two ways from all described fungal alpha-amylases: they were predicted to be glycosylphosphatidyllinosit

  1. Two novel, putatively cell wall-associated and glycosylphosphatidylinositol-anchored α-glucanotransferase enzymes of Aspergillus niger

    NARCIS (Netherlands)

    Kaaij, R.M. van der; Yuan, X.L.; Franken, A.; Ram, A.F.J.; Punt, P.J.; Maarel, M.J.E.C. van der; Dijkhuizen, L.

    2007-01-01

    In the genome sequence of Aspergillus niger CBS 513.88, three genes were identified with high similarity to fungal α-amylases. The protein sequences derived from these genes were different in two ways from all described fungal α-amylases: they were predicted to be glycosylphosphatidylinositol anchor

  2. Diversity of Aspergillus oryzae genotypes (RFLP) isolated from traditional soy sauce production within Malaysia and Southeast Asia

    Science.gov (United States)

    DNA fingerprinting was performed on 64 strains of Aspergillus oryzae and one strain of A. sojae isolated from soysauce factories within Malaysia and Southeast Asia that use primitive traditional methods in producing 'tamari type' Cantonese soy sauce. PstI digests of total genomic DNA from each isol...

  3. Aspergillus niger: an unusual cause of invasive pulmonary aspergillosis

    OpenAIRE

    Person, A. K.; Chudgar, S. M.; Norton, B. L.; Tong, B. C.; Stout, J E

    2010-01-01

    Infections due to Aspergillus species cause significant morbidity and mortality. Most are attributed to Aspergillus fumigatus, followed by Aspergillus flavus and Aspergillus terreus. Aspergillus niger is a mould that is rarely reported as a cause of pneumonia. A 72-year-old female with chronic obstructive pulmonary disease and temporal arteritis being treated with steroids long term presented with haemoptysis and pleuritic chest pain. Chest radiography revealed areas of heterogeneous consolid...

  4. rtfA, a putative RNA-Pol II transcription elongation factor gene, is necessary for normal morphological and chemical development in Aspergillus flavus.

    Science.gov (United States)

    Lohmar, Jessica M; Harris-Coward, Pamela Y; Cary, Jeffrey W; Dhingra, Sourabh; Calvo, Ana M

    2016-06-01

    The filamentous fungus Aspergillus flavus is an agriculturally important opportunistic plant pathogen that produces potent carcinogenic compounds called aflatoxins. We identified the A. flavus rtfA gene, the ortholog of rtf1 in Saccharomyces cerevisiae and rtfA in Aspergillus nidulans. Interestingly, rtfA has multiple cellular roles in this mycotoxin-producing fungus. In this study, we show that rtfA regulates conidiation. The rtfA deletion mutant presented smaller conidiophores with significantly reduced conidial production compared to the wild-type strain. The absence of rtfA also resulted in a significant decrease or lack of sclerotial production under conditions that allowed abundant production of these resistance structures in the wild type. Importantly, the deletion of rtfA notably reduced the production of aflatoxin B1, indicating that rtfA is a regulator of mycotoxin biosynthesis in A. flavus. In addition, the deletion rtfA also altered the production of several unknown secondary metabolites indicating a broader regulatory scope. Furthermore, our study revealed that rtfA controls the expression of the global regulators veA and laeA, which further influence morphogenesis and secondary metabolism in A. flavus. PMID:27020290

  5. Genetic diversity of Aspergillus species isolated from onychomycosis and Aspergillus hongkongensis sp. nov., with implications to antifungal susceptibility testing.

    Science.gov (United States)

    Tsang, Chi-Ching; Hui, Teresa W S; Lee, Kim-Chung; Chen, Jonathan H K; Ngan, Antonio H Y; Tam, Emily W T; Chan, Jasper F W; Wu, Andrea L; Cheung, Mei; Tse, Brian P H; Wu, Alan K L; Lai, Christopher K C; Tsang, Dominic N C; Que, Tak-Lun; Lam, Ching-Wan; Yuen, Kwok-Yung; Lau, Susanna K P; Woo, Patrick C Y

    2016-02-01

    Thirteen Aspergillus isolates recovered from nails of 13 patients (fingernails, n=2; toenails, n=11) with onychomycosis were characterized. Twelve strains were identified by multilocus sequencing as Aspergillus spp. (Aspergillus sydowii [n=4], Aspergillus welwitschiae [n=3], Aspergillus terreus [n=2], Aspergillus flavus [n=1], Aspergillus tubingensis [n=1], and Aspergillus unguis [n=1]). Isolates of A. terreus, A. flavus, and A. unguis were also identifiable by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The 13th isolate (HKU49(T)) possessed unique morphological characteristics different from other Aspergillus spp. Molecular characterization also unambiguously showed that HKU49(T) was distinct from other Aspergillus spp. We propose the novel species Aspergillus hongkongensis to describe this previously unknown fungus. Antifungal susceptibility testing showed most Aspergillus isolates had low MICs against itraconazole and voriconazole, but all Aspergillus isolates had high MICs against fluconazole. A diverse spectrum of Aspergillus species is associated with onychomycosis. Itraconazole and voriconazole are probably better drug options for Aspergillus onychomycosis. PMID:26658315

  6. Aspergillus uvarum sp. nov., an uniseriate black Aspergillus species isolated from grapes in Europe

    DEFF Research Database (Denmark)

    Perrone, Giancarlo; Varga, János; Susca, Antonia;

    2008-01-01

    A novel species, Aspergillus uvarum sp. nov., is described within Aspergillus section Nigri. This species can be distinguished from other black aspergilli based on internal transcribed spacers (ITS), beta-tubulin and calmodulin gene sequences, by AFLP analysis and by extrolite profiles. Aspergill...... atypical strains of Aspergillus aculeatus, CBS 114.80 and CBS 620.78, and was isolated from grape berries in Portugal, Italy, France, Israel, Greece and Spain. The type strain of Aspergillus uvarum sp. nov. is IMI 388523(T)=CBS 127591(T)= ITEM 4834(T)= IBT26606(T)....

  7. Challenges in Whole-Genome Annotation of Pyrosequenced Eukaryotic Genomes

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, Alan; Grigoriev, Igor

    2009-04-17

    Pyrosequencing technologies such as 454/Roche and Solexa/Illumina vastly lower the cost of nucleotide sequencing compared to the traditional Sanger method, and thus promise to greatly expand the number of sequenced eukaryotic genomes. However, the new technologies also bring new challenges such as shorter reads and new kinds and higher rates of sequencing errors, which complicate genome assembly and gene prediction. At JGI we are deploying 454 technology for the sequencing and assembly of ever-larger eukaryotic genomes. Here we describe our first whole-genome annotation of a purely 454-sequenced fungal genome that is larger than a yeast (>30 Mbp). The pezizomycotine (filamentous ascomycote) Aspergillus carbonarius belongs to the Aspergillus section Nigri species complex, members of which are significant as platforms for bioenergy and bioindustrial technology, as members of soil microbial communities and players in the global carbon cycle, and as agricultural toxigens. Application of a modified version of the standard JGI Annotation Pipeline has so far predicted ~;;10k genes. ~;;12percent of these preliminary annotations suffer a potential frameshift error, which is somewhat higher than the ~;;9percent rate in the Sanger-sequenced and conventionally assembled and annotated genome of fellow Aspergillus section Nigri member A. niger. Also,>90percent of A. niger genes have potential homologs in the A. carbonarius preliminary annotation. Weconclude, and with further annotation and comparative analysis expect to confirm, that 454 sequencing strategies provide a promising substrate for annotation of modestly sized eukaryotic genomes. We will also present results of annotation of a number of other pyrosequenced fungal genomes of bioenergy interest.

  8. Phylogeny and subgeneric taxonomy of Aspergillus

    DEFF Research Database (Denmark)

    Peterson, S.W.; Varga, Janos; Frisvad, Jens Christian; Samson, Robert A.

    The phylogeny of the genus Aspergillus and its teleomorphs is discussed based on multilocus sequence data. DNA sequence analysis was used to formulate a nucleotide sequence framework of the genus and to analyze character changes in relationship to the phylogeny hypothesized from the DNA sequence...... analysis. The sequence data used to delimitate subgeneric taxa included partial calmodulin, rDNA and RNA polymerase gene sequences. In our phylogenic structure of Aspergillus extrolite data of the various Aspergillus taxa collected from ex-type cultures and numerous other isolates are also discussed. A new...... subgeneric classification is proposed which includes 8 subgenera and 22 sections within the Aspergillus genus. Characteristics of these taxa are shortly discussed in this chapter....

  9. Putative virulence factors of Aspergillus fumigatus

    NARCIS (Netherlands)

    Tomee, JFC; Kauffman, HF

    2000-01-01

    Various putative virulence factors of Aspergillus fumigatus have been studied over the past decades. A. fumigatus gliotoxin is a potent inhibitor of the mucociliary system. Several fungal metabolites interfere with phagocytosis and opsonization including toxins, 'conidial inhibitory factor', 'A. fum

  10. Polyketides in Aspergillus terreus: biosynthesis pathway discovery and application.

    Science.gov (United States)

    Yin, Ying; Cai, Menghao; Zhou, Xiangshan; Li, Zhiyong; Zhang, Yuanxing

    2016-09-01

    The knowledge of biosynthesis gene clusters, production improving methods, and bioactivity mechanisms is very important for the development of filamentous fungi metabolites. Metabolic engineering and heterologous expression methods can be applied to improve desired metabolite production, when their biosynthesis pathways have been revealed. And, stable supplement is a necessary basis of bioactivity mechanism discovery and following clinical trial. Aspergillus terreus is an outstanding producer of many bioactive agents, and a large part of them are polyketides. In this review, we took polyketides from A. terreus as examples, focusing on 13 polyketide synthase (PKS) genes in A. terreus NIH 2624 genome. The biosynthesis pathways of nine PKS genes have been reported, and their downstream metabolites are lovastatin, terreic acid, terrein, geodin, terretonin, citreoviridin, and asperfuranone, respectively. Among them, lovastatin is a well-known hypolipidemic agent. Terreic acid, terrein, citreoviridin, and asperfuranone show good bioactivities, especially anticancer activities. On the other hand, geodin and terretonin are mycotoxins. So, biosynthesis gene cluster information is important for the production or elimination of them. We also predicted three possible gene clusters that contain four PKS genes by homologous gene alignment with other Aspergillus strains. We think that this is an effective way to mine secondary metabolic gene clusters. PMID:27455860

  11. Data on the presence or absence of genes encoding essential proteins for ochratoxin and fumonisin biosynthesis in Aspergillus niger and Aspergillus welwitschiae.

    Science.gov (United States)

    Massi, Fernanda Pelisson; Sartori, Daniele; Ferranti, Larissa de Souza; Iamanaka, Beatriz Thie; Taniwaki, Marta Hiromi; Vieira, Maria Lucia Carneiro; Fungaro, Maria Helena Pelegrinelli

    2016-06-01

    We present the multiplex PCR data for the presence/absence of genes involved in OTA and FB2 biosynthesis in Aspergillus niger/Aspergillus welwitschiae strains isolated from different food substrates in Brazil. Among the 175 strains analyzed, four mPCR profiles were found: Profile 1 (17%) highlights strains harboring in their genome the pks, radH and the fum8 genes. Profile 2 (3.5%) highlights strains harboring genes involved in OTA biosynthesis i.e. radH and pks. Profile 3 (51.5%) highlights strains harboring the fum8 gene. Profile 4 (28%) highlights strains not carrying the genes studied herein. This research content is supplemental to our original research article, "Prospecting for the incidence of genes involved in ochratoxin and fumonisin biosynthesis in Brazilian strains of A. niger and A. welwitschiae" [1]. PMID:27054181

  12. Data on the presence or absence of genes encoding essential proteins for ochratoxin and fumonisin biosynthesis in Aspergillus niger and Aspergillus welwitschiae

    Science.gov (United States)

    Massi, Fernanda Pelisson; Sartori, Daniele; Ferranti, Larissa de Souza; Iamanaka, Beatriz Thie; Taniwaki, Marta Hiromi; Vieira, Maria Lucia Carneiro; Fungaro, Maria Helena Pelegrinelli

    2016-01-01

    We present the multiplex PCR data for the presence/absence of genes involved in OTA and FB2 biosynthesis in Aspergillus niger/Aspergillus welwitschiae strains isolated from different food substrates in Brazil. Among the 175 strains analyzed, four mPCR profiles were found: Profile 1 (17%) highlights strains harboring in their genome the pks, radH and the fum8 genes. Profile 2 (3.5%) highlights strains harboring genes involved in OTA biosynthesis i.e. radH and pks. Profile 3 (51.5%) highlights strains harboring the fum8 gene. Profile 4 (28%) highlights strains not carrying the genes studied herein. This research content is supplemental to our original research article, “Prospecting for the incidence of genes involved in ochratoxin and fumonisin biosynthesis in Brazilian strains of A. niger and A. welwitschiae” [1]. PMID:27054181

  13. In-silico analysis of Aspergillus niger beta-glucosidases

    Science.gov (United States)

    Yeo S., L.; Shazilah, K.; Suhaila, S.; Abu Bakar F., D.; Murad A. M., A.

    2014-09-01

    Genomic data mining was carried out and revealed a total of seventeen β-glucosidases in filamentous fungi Aspergillus niger. Two of them belonged to glycoside hydrolase family 1 (GH1) while the rest belonged to genes in family 3 (GH3). These proteins were then named according to the nomenclature as proposed by the International Union of Biochemistry (IUB), starting from the lowest pI and glycoside hydrolase family. Their properties were predicted using various bionformatic tools showing the presence of domains for signal peptide and active sites. Interestingly, one particular domain, PA14 (protective antigen) was present in four of the enzymes, predicted to be involved in carbohydrate binding. A phylogenetic tree grouped the two glycoside hydrolase families with GH1 and GH3 related organisms. This study showed that the various domains present in these β-glucosidases are postulated to be crucial for the survival of this fungus, as supported by other analysis.

  14. Scientific Advances with Aspergillus Species that Are Used for Food and Biotech Applications.

    Science.gov (United States)

    Biesebeke, Rob Te; Record, Erik

    2008-01-01

    Yeast and filamentous fungi have been used for centuries in diverse biotechnological processes. Fungal fermentation technology is traditionally used in relation to food production, such as for bread, beer, cheese, sake and soy sauce. Last century, the industrial application of yeast and filamentous fungi expanded rapidly, with excellent examples such as purified enzymes and secondary metabolites (e.g. antibiotics), which are used in a wide range of food as well as non-food industries. Research on protein and/or metabolite secretion by fungal species has focused on identifying bottlenecks in (post-) transcriptional regulation of protein production, metabolic rerouting, morphology and the transit of proteins through the secretion pathway. In past years, genome sequencing of some fungi (e.g. Aspergillus oryzae, Aspergillus niger) has been completed. The available genome sequences have enabled identification of genes and functionally important regions of the genome. This has directed research to focus on a post-genomics era in which transcriptomics, proteomics and metabolomics methodologies will help to explore the scientific relevance and industrial application of fungal genome sequences. PMID:21558706

  15. Ribonuclease Production by Aspergillus species

    Directory of Open Access Journals (Sweden)

    Eleni Gomes

    1998-09-01

    Full Text Available Ribonuclease production by Aspergillus flavipes, A. sulphureus and A. fischeri in semi-synthetic medium, after 24-144 hours at 30ºC under shaking, was studied. After cultivation, the medium was separated from micelia by filtration and the resultant solution was used as enzymatic extract. The highest amount of biomass and RNase was obtained after 96 hours of cultivation. The enzymes produced by three species presented similar characteristics, with optimum temperature at 55ºC and two peaks of activity at pH 4.5 and 7.0. A. flavipes RNases were more sensitive to temperature: 50% of the initial activity was lost after 1 hour at 70ºC. After this heat treatment, RNase of A. sulphureus lost 30% of this activity and that of A. fischeri only 16%. The nucleotides released by enzimatic hydrolysis of RNA were separated by ion exchange chromatography in a AG-1X8-formiate column and identified by paper chromatography. This procedure indicated that the raw enzymatic extract of Aspergillus flavipes is able to hydrolyze RNA, releasing 3'-nucleotides monophosphate at pH 4.5 and 3' and 5'-nucleotides monophosphate at pH 7.0 and 8.5. This result suggests that this strain produces two different types of RNase, one acidic and other alcaline, with different specificities.A produção de ribonucleases extracelulares pelos fungos Aspergillus flavipes, A. sulphureus e A. fischeri foi estudada em meio semi-sintético por períodos de 24 a 144 horas, em "shaker" a 30ºC. Após o cultivo, o meio foi separado da massa micelial por filtração, sendo o filtrado utilizado como solução enzimática bruta. As três espécies produziram maior quantidade de biomassa e ribonuclease após 96 horas de cultivo. O estudo das RNases como extrato enzimático bruto demonstrou que existe grande similaridade entre as enzimas das três espécies, com temperaturas ótimas de 55ºC e dois picos de atividade a pH 4,5 e a pH 7,0. A RNAse produzida pelo fungo A. flavipes demonstrou ser mais

  16. Estimating microalgae Synechococcus nidulans daily biomass concentration using neuro-fuzzy network

    Directory of Open Access Journals (Sweden)

    Vitor Badiale Furlong

    2013-02-01

    Full Text Available In this study, a neuro-fuzzy estimator was developed for the estimation of biomass concentration of the microalgae Synechococcus nidulans from initial batch concentrations, aiming to predict daily productivity. Nine replica experiments were performed. The growth was monitored daily through the culture medium optic density and kept constant up to the end of the exponential phase. The network training followed a full 3³ factorial design, in which the factors were the number of days in the entry vector (3,5 and 7 days, number of clusters (10, 30 and 50 clusters and internal weight softening parameter (Sigma (0.30, 0.45 and 0.60. These factors were confronted with the sum of the quadratic error in the validations. The validations had 24 (A and 18 (B days of culture growth. The validations demonstrated that in long-term experiments (Validation A the use of a few clusters and high Sigma is necessary. However, in short-term experiments (Validation B, Sigma did not influence the result. The optimum point occurred within 3 days in the entry vector, 10 clusters and 0.60 Sigma and the mean determination coefficient was 0.95. The neuro-fuzzy estimator proved a credible alternative to predict the microalgae growth.

  17. Effects of long-wavelength ultraviolet (UV-A) radiation on the growth of Anacystis Nidulans

    International Nuclear Information System (INIS)

    The growth of Anacystis nidulans cells which had been grown under visible light only (>390 nm) was suppressed by long-wavelength ultraviolet (UV-A, 320-390 nm) radiation. The growth resumed after 24 h. Cells grown under UV-A supplemented light contained less chlorophyll and phycocyanin and more carotenoid than control cells. The finding that UV-A radiation inhibited the rate of delta-aminolevulinic acid synthesis indicated that the decreases in the photosynthetic pigments were mainly due to the inhibition of their biosynthesis rather than to photodestruction of pigments by UV-A radiation. The primary cause of the inhibitory effects seems to be the inhibition of the photosynthetic process which can be measured as the rho-benzoquinone Hill reaction. Previous exposure to UV-A radiation conferred some resistance on the cells to this inhibitory radiation. Thus UV-A radiation itself may activate a system that repairs damage caused by UV-A radiation and/or protects against the radiation. (author)

  18. Effect of carbon and nitrogen assimilation on chlorophyll fluorescence emission by the cyanobacterium Anacystis nidulans

    Energy Technology Data Exchange (ETDEWEB)

    Romero, J.M.; Lara, C. (Instituto de Bioquimica Vegetal y Fotosintesis, Univ. de Sevilla y CSIC, Sevilla (ES)); Sivak, M.N. (Dept. of Biochemistry, Michigan State Univ., East Lansing (US))

    1992-01-01

    O{sub 2} evolution and chlorophyll A fluorescence emission have been monitored in intact cells of the cyanobacterium Anacystis nidulans 1402-1 to study the influence of carbon and nitrogen assimilation on the operation of the photosynthetic apparatus. The pattern of fluorescence induction in dark-adapted cyanobacterial cells was different from that of higher plants. Cyanobacteria undergo large, rapid state transitions upon illumination, which lead to marked changes in the fluorescence yield, complicating the estimation of quenching coefficients. The Kautsky effect was not evident, although it could be masked by a state II-state I transition, upon illumination with actinic light. The use of inhibitors of carbon assimilation such as D,L-glyceraldehyde or iodoacetamide allowed us to relate changes in variable fluorescence to active CO{sub 2} fixation. Ammonium, but not nitrate, induced non-photochemical fluorescence quenching, in agreement with a previous report on green algae, indicative of an ammonium-induced state i transition. (au).

  19. Neuroimaging features of cerebral aspergillus abscess: Case report

    Directory of Open Access Journals (Sweden)

    Jie Bai

    2015-06-01

    Conclusion: Cerebral aspergillus abscesses possess some degree neuroimaging features on traditional CT/MR imaging. Combined with patient's clinical history, CT/MRI examination could facilitate early diagnosis of aspergillus abscesses in central nervous system.

  20. Virulence of catalase-deficient aspergillus nidulans in p47(phox)-/- mice. Implications for fungal pathogenicity and host defense in chronic granulomatous disease.

    OpenAIRE

    Chang, Y.C.; Segal, B.H.; Holland, S M; Miller, G.F.; Kwon-Chung, K. J.

    1998-01-01

    Chronic granulomatous disease (CGD) is a rare genetic disorder in which phagocytes fail to produce superoxide because of defects in one of several components of the NADPH oxidase complex. As a result, patients develop recurrent life-threatening bacterial and fungal infections. The organisms to which CGD patients are most susceptible produce catalase, regarded as an important factor for microbial pathogenicity in CGD. To test the role of pathogen-derived catalase in CGD directly, we have gener...

  1. Post-Synthetic Defucosylation of AGP by Aspergillus nidulans α-1,2-Fucosidase Expressed in Arabidopsis Apoplast Induces Compensatory Upregulation of α-1,2-Fucosyltransferases

    Science.gov (United States)

    Pogorelko, Gennady V.; Reem, Nathan T.; Young, Zachary T.; Chambers, Lauran; Zabotina, Olga A.

    2016-01-01

    Cell walls are essential components of plant cells which perform a variety of important functions for the different cell types, tissues and organs of a plant. Besides mechanical function providing cell shape, cell walls participate in intercellular communication, defense during plant-microbe interactions, and plant growth. The plant cell wall consists predominantly of polysaccharides with the addition of structural glycoproteins, phenolic esters, minerals, lignin, and associated enzymes. Alterations in the cell wall composition created through either changes in biosynthesis of specific constituents or their post-synthetic modifications in the apoplast compromise cell wall integrity and frequently induce plant compensatory responses as a result of these alterations. Here we report that post-synthetic removal of fucose residues specifically from arabinogalactan proteins in the Arabidopsis plant cell wall induces differential expression of fucosyltransferases and leads to the root and hypocotyl elongation changes. These results demonstrate that the post-synthetic modification of cell wall components presents a valuable approach to investigate the potential signaling pathways induced during plant responses to such modifications that usually occur during plant development and stress responses. PMID:27448235

  2. Post-Synthetic Defucosylation of AGP by Aspergillus nidulans α-1,2-Fucosidase Expressed in Arabidopsis Apoplast Induces Compensatory Upregulation of α-1,2-Fucosyltransferases.

    Science.gov (United States)

    Pogorelko, Gennady V; Reem, Nathan T; Young, Zachary T; Chambers, Lauran; Zabotina, Olga A

    2016-01-01

    Cell walls are essential components of plant cells which perform a variety of important functions for the different cell types, tissues and organs of a plant. Besides mechanical function providing cell shape, cell walls participate in intercellular communication, defense during plant-microbe interactions, and plant growth. The plant cell wall consists predominantly of polysaccharides with the addition of structural glycoproteins, phenolic esters, minerals, lignin, and associated enzymes. Alterations in the cell wall composition created through either changes in biosynthesis of specific constituents or their post-synthetic modifications in the apoplast compromise cell wall integrity and frequently induce plant compensatory responses as a result of these alterations. Here we report that post-synthetic removal of fucose residues specifically from arabinogalactan proteins in the Arabidopsis plant cell wall induces differential expression of fucosyltransferases and leads to the root and hypocotyl elongation changes. These results demonstrate that the post-synthetic modification of cell wall components presents a valuable approach to investigate the potential signaling pathways induced during plant responses to such modifications that usually occur during plant development and stress responses. PMID:27448235

  3. Post-Synthetic Defucosylation of AGP by Aspergillus nidulans α-1,2-Fucosidase Expressed in Arabidopsis Apoplast Induces Compensatory Upregulation of α-1,2-Fucosyltransferases.

    Directory of Open Access Journals (Sweden)

    Gennady V Pogorelko

    Full Text Available Cell walls are essential components of plant cells which perform a variety of important functions for the different cell types, tissues and organs of a plant. Besides mechanical function providing cell shape, cell walls participate in intercellular communication, defense during plant-microbe interactions, and plant growth. The plant cell wall consists predominantly of polysaccharides with the addition of structural glycoproteins, phenolic esters, minerals, lignin, and associated enzymes. Alterations in the cell wall composition created through either changes in biosynthesis of specific constituents or their post-synthetic modifications in the apoplast compromise cell wall integrity and frequently induce plant compensatory responses as a result of these alterations. Here we report that post-synthetic removal of fucose residues specifically from arabinogalactan proteins in the Arabidopsis plant cell wall induces differential expression of fucosyltransferases and leads to the root and hypocotyl elongation changes. These results demonstrate that the post-synthetic modification of cell wall components presents a valuable approach to investigate the potential signaling pathways induced during plant responses to such modifications that usually occur during plant development and stress responses.

  4. Enzymatic synthesis of β-xylosyl-oligosaccharides by transxylosylation using two beta-xylosidases of glycoside hydrolase family 3 from Aspergillus nidulans FGSC A4

    DEFF Research Database (Denmark)

    Dilokpimol, Adiphol; Nakai, Hiroyuki; Gotfredsen, Charlotte Held;

    2011-01-01

    alcohols as acceptors 18 different p-xylosyl-oligosaccharides were synthesised in 2-36% (BxlA) and 6-66% (BxlB) yields by transxylosylation. BxlA utilised the monosaccharides D-mannose, D-lyxose, D-talose, D-xylose, D-arabinose, L-fucose, D-glucose, D-galactose and D-fructose as acceptors, whereas Bxl......B used the same except for D-lyxose, D-arabinose and L-fucose. BxlB transxylosylated the disaccharides xylobiose, lactulose, sucrose, lactose and turanose in upto 35% yield, while BxlA gave inferior yields on these acceptors. The regioselectivity was acceptor dependent and primarily involved beta-1,4 or...

  5. Chemodiversity in the genus Aspergillus

    DEFF Research Database (Denmark)

    Frisvad, Jens Christian; Larsen, Thomas Ostenfeld

    2015-01-01

    characterized. The genus Aspergillus is cladistically holophyletic but phenotypically polythetic and very diverse and is associated to quite different sexual states. Following the one fungus one name system, the genus Aspergillus is restricted to a holophyletic clade that include the morphologically different...... biosynthetic family isoextrolites. However, it appears that secondary metabolites from one Aspergillus section have analogous metabolites in other sections (here also called heteroisoextrolites). In this review, we give a genus-wide overview of secondary metabolite production in Aspergillus species. Extrolites...

  6. Aspergillus species: An emerging pathogen in onychomycosis among diabetics

    OpenAIRE

    Wijesuriya, T. M.; Kottahachchi, J.; T. D. C. P. Gunasekara; Bulugahapitiya, U.; K. N. P. Ranasinghe; Neluka Fernando, S. S.; M M Weerasekara

    2015-01-01

    Introduction: Approximately, 33% patients with diabetes are afflicted with onychomycosis. In the past, nondermatophyte molds have been regarded as opportunistic pathogens; recently, Aspergillus species are considered as emerging pathogens of toenail infections. In Sri Lanka, the prevalence of Aspergillus species in onychomycosis among diabetics is not well documented. Objective: To determine the proportion of Aspergillus onychomycosis, risk factors and knowledge among diabetics. Materials and...

  7. 21 CFR 866.3040 - Aspergillus spp. serological reagents.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Aspergillus spp. serological reagents. 866.3040... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3040 Aspergillus spp. serological reagents. (a) Identification. Aspergillus spp. serological reagents are devices...

  8. Combined molecular and biochemical approach identifies Aspergillus japonicus and Aspergillus aculeatus as two species

    DEFF Research Database (Denmark)

    Parenicova, L.; Skouboe, P.; Frisvad, Jens Christian; Samson, R.A.; Rossen, L.; Hoor-Suykerbuyk, M.; Visser, J.

    2001-01-01

    We examined nine Aspergillus japonicus isolates and 10 Aspergillus aculeatus isolates by using molecular and biochemical markers, including DNA sequences of the ITS1-5.8S rRNA gene-ITS2 region, restriction fragment length polymorphisms (RFLP), and secondary-metabolite profiles. The DNA sequence of...... the internal transcribed spacers (ITS1 and ITS2) and the 5.8S rRNA gene could not be used to distinguish between A. japonicus and A. aculeatus but did show that these two taxa are more closely related to each other than to other species of black aspergilli. Aspergillus niger pyruvate kinase (pkiA) and...

  9. The binding of zinc ions to Emericella nidulans endo-β-1,4-galactanase is essential for crystal formation

    DEFF Research Database (Denmark)

    Otten, Harm; Michalak, Malwina; Mikkelsen, Jørn Dalgaard;

    2013-01-01

    A novel Emericella nidulans endo-β-1,4-galactanase (EnGAL) demonstrates a strong capacity to generate high levels of very potent prebiotic oligosaccharides from potato pulp, a by-product of the agricultural potato-starch industry. EnGAL belongs to glycoside hydrolase family 53 and shows high (72...... belonging to GH53. It also revealed 15 zinc ions bound to the protein, one of which is located in the active site, where it is coordinated by residues Glu136 and Glu246 which comprise the catalytic machinery. The majority of the zinc ions are located on the surface of the enzyme, in some cases with side...

  10. A rare case of bilateral aspergillus endophthalmitis

    Science.gov (United States)

    Gupta, Saurabh; Loudill, Cameron; Tammara, Anita; Chow, Robert T.

    2015-01-01

    Aspergillus endophthalmitis is a devastating inflammatory condition of the intraocular cavities that may result in irreparable loss of vision and rapid destruction of the eye. Almost all cases in the literature have shown an identified source causing aspergillus endophthalmitis as a result of direct extension of disease. We present a rare case of bilateral aspergillus endophthalmitis. A 72-year-old woman with a history of diabetes mellitus, congenital Hirschsprung disease, and recent culture-positive candida pyelonephritis with hydronephrosis status post-surgical stent placement presented with difficulty opening her eyes. She complained of decreased vision (20/200) with pain and redness in both eyes – right worse then left. Examination demonstrated multiple white fungal balls in both retinas consistent with bilateral fungal endophthalmitis. Bilateral vitreous taps for cultures and staining were performed. Patient was given intravitreal injections of amphotericin B, vancomycin, ceftazidime, and started on oral fluconazole. Patient was scheduled for vitrectomy to decrease organism burden and to remove loculated areas of infection that would not respond to systemic antifungal agents. Four weeks after initial presentation, the fungal cultures revealed mold growth consistent with aspergillus. Patient was subsequently started on voriconazole and fluconazole was discontinued due to poor efficacy against aspergillus. Further workup was conducted to evaluate for the source of infection and seeding. Transthoracic cardiogram was unremarkable for any vegetation or valvular abnormalities. MRI of the orbits and sinuses did not reveal any mass lesions or bony destruction. CT of the chest was unremarkable for infection. Aspergillus endophthalmitis may occur because of one of these several mechanisms: hematogenous dissemination, direct inoculation by trauma, and contamination during surgery. Our patient's cause of bilateral endophthalmitis was through an unknown iatrogenic seed

  11. A rare case of bilateral aspergillus endophthalmitis.

    Science.gov (United States)

    Gupta, Saurabh; Loudill, Cameron; Tammara, Anita; Chow, Robert T

    2015-01-01

    Aspergillus endophthalmitis is a devastating inflammatory condition of the intraocular cavities that may result in irreparable loss of vision and rapid destruction of the eye. Almost all cases in the literature have shown an identified source causing aspergillus endophthalmitis as a result of direct extension of disease. We present a rare case of bilateral aspergillus endophthalmitis. A 72-year-old woman with a history of diabetes mellitus, congenital Hirschsprung disease, and recent culture-positive candida pyelonephritis with hydronephrosis status post-surgical stent placement presented with difficulty opening her eyes. She complained of decreased vision (20/200) with pain and redness in both eyes - right worse then left. Examination demonstrated multiple white fungal balls in both retinas consistent with bilateral fungal endophthalmitis. Bilateral vitreous taps for cultures and staining were performed. Patient was given intravitreal injections of amphotericin B, vancomycin, ceftazidime, and started on oral fluconazole. Patient was scheduled for vitrectomy to decrease organism burden and to remove loculated areas of infection that would not respond to systemic antifungal agents. Four weeks after initial presentation, the fungal cultures revealed mold growth consistent with aspergillus. Patient was subsequently started on voriconazole and fluconazole was discontinued due to poor efficacy against aspergillus. Further workup was conducted to evaluate for the source of infection and seeding. Transthoracic cardiogram was unremarkable for any vegetation or valvular abnormalities. MRI of the orbits and sinuses did not reveal any mass lesions or bony destruction. CT of the chest was unremarkable for infection. Aspergillus endophthalmitis may occur because of one of these several mechanisms: hematogenous dissemination, direct inoculation by trauma, and contamination during surgery. Our patient's cause of bilateral endophthalmitis was through an unknown iatrogenic seed

  12. A rare case of bilateral aspergillus endophthalmitis

    Directory of Open Access Journals (Sweden)

    Saurabh Gupta

    2015-12-01

    Full Text Available Aspergillus endophthalmitis is a devastating inflammatory condition of the intraocular cavities that may result in irreparable loss of vision and rapid destruction of the eye. Almost all cases in the literature have shown an identified source causing aspergillus endophthalmitis as a result of direct extension of disease. We present a rare case of bilateral aspergillus endophthalmitis. A 72-year-old woman with a history of diabetes mellitus, congenital Hirschsprung disease, and recent culture-positive candida pyelonephritis with hydronephrosis status post-surgical stent placement presented with difficulty opening her eyes. She complained of decreased vision (20/200 with pain and redness in both eyes – right worse then left. Examination demonstrated multiple white fungal balls in both retinas consistent with bilateral fungal endophthalmitis. Bilateral vitreous taps for cultures and staining were performed. Patient was given intravitreal injections of amphotericin B, vancomycin, ceftazidime, and started on oral fluconazole. Patient was scheduled for vitrectomy to decrease organism burden and to remove loculated areas of infection that would not respond to systemic antifungal agents. Four weeks after initial presentation, the fungal cultures revealed mold growth consistent with aspergillus. Patient was subsequently started on voriconazole and fluconazole was discontinued due to poor efficacy against aspergillus. Further workup was conducted to evaluate for the source of infection and seeding. Transthoracic cardiogram was unremarkable for any vegetation or valvular abnormalities. MRI of the orbits and sinuses did not reveal any mass lesions or bony destruction. CT of the chest was unremarkable for infection. Aspergillus endophthalmitis may occur because of one of these several mechanisms: hematogenous dissemination, direct inoculation by trauma, and contamination during surgery. Our patient's cause of bilateral endophthalmitis was through an

  13. Aspergillus species: An emerging pathogen in onychomycosis among diabetics

    Science.gov (United States)

    Wijesuriya, T. M.; Kottahachchi, J.; Gunasekara, T. D. C. P.; Bulugahapitiya, U.; Ranasinghe, K. N. P.; Neluka Fernando, S. S.; Weerasekara, M. M.

    2015-01-01

    Introduction: Approximately, 33% patients with diabetes are afflicted with onychomycosis. In the past, nondermatophyte molds have been regarded as opportunistic pathogens; recently, Aspergillus species are considered as emerging pathogens of toenail infections. In Sri Lanka, the prevalence of Aspergillus species in onychomycosis among diabetics is not well documented. Objective: To determine the proportion of Aspergillus onychomycosis, risk factors and knowledge among diabetics. Materials and Methods: This was descriptive cross-sectional study. Three hundred diabetic patients were included. Clinical examinations of patients’ toenails were performed by a clinical microbiologist. Laboratory identification was done, and pathogens were identified to the species level by morpho-physiological methods. All inferential statistics were tested at P onychomycosis. Aspergillus species were most commonly isolated n = 180 (71%) followed by dermatophytes, yeasts, and other molds n = 75 (29%). Of the patients having Aspergillus onychomycosis, 149 (83%) were in the > age group. In men, Aspergillus onycomycosis was seen in 82%. Among patients who had Aspergillus nail infection, 114 (63%) had diabetes for a period of > years. Among patients who were engaged in agricultural activities, 77% were confirmed to have infected nails due to Aspergillus species. Conclusion: Aspergillus niger was the most common pathogen isolated from toenail infection. Aspergillus species should be considered as an important pathogen in toenail onychomycosis in diabetic patients. Risk factors associated with Aspergillus onychomycosis were age, gender, duration of diabetes, length of exposure to fungi, and occupation. PMID:26693433

  14. The transcriptional activator GaaR of Aspergillus niger is required for release and utilization of D-galacturonic acid from pectin

    NARCIS (Netherlands)

    Alazi, Ebru; Niu, Jing; Kowalczyk, Joanna E; Peng, Mao; Aguilar Pontes, Maria Victoria; van Kan, Jan A L; Visser, Jaap; de Vries, Ronald P; Ram, Arthur F J

    2016-01-01

    We identified the D-galacturonic acid (GA) responsive transcriptional activator GaaR of the saprotrophic fungus Aspergillus niger, which was found to be essential for growth on GA and polygalacturonic acid (PGA). Growth of the ΔgaaR strain was reduced on complex pectins. Genome-wide expression analy

  15. The transcriptional activator GaaR of Aspergillus niger is required for release and utilization of d-galacturonic acid from pectin

    NARCIS (Netherlands)

    Alazi, Ebru; Niu, Jing; Kowalczyk, Joanna E.; Peng, Mao; Aguilar Pontes, Maria Victoria; Kan, Van Jan A.L.; Visser, Jaap; Vries, De Ronald P.; Ram, Arthur F.J.

    2016-01-01

    We identified the d-galacturonic acid (GA)-responsive transcriptional activator GaaR of the saprotrophic fungus, Aspergillus niger, which was found to be essential for growth on GA and polygalacturonic acid (PGA). Growth of the ΔgaaR strain was reduced on complex pectins. Genome-wide expression anal

  16. Aspergillus niger mstA encodes a high affinity sugar/H+ symporter which is regulated in persponse to extracellular pH

    NARCIS (Netherlands)

    Kuyk, van P.A.; Diderich, J.A.; MacCabe, A.P.; Hererro, O.; Ruijter, G.J.G.; Visser, J.

    2004-01-01

    A sugar-transporter-encoding gene, mstA, which is a member of the major facilitator superfamily, has been cloned from a genomic DNA library of the filamentous fungus Aspergillus niger. To enable the functional characterization of MSTA, a full-length cDNA was expressed in a Saccharomyces cerevisiae s

  17. Identification and toxigenic potential of the industrially important fungi, Aspergillus oryzae and Aspergillus sojae

    DEFF Research Database (Denmark)

    Jørgensen, Thomas R

    2007-01-01

    Mold strains belonging to the species Aspergillus oryzae and Aspergillus sojae are highly valued as koji molds in the traditional preparation of fermented foods, such as miso, sake, and shoyu, and as protein production hosts in modern industrial processes. A. oryzae and A. sojae are relatives of...... the wild molds Aspergillus flavus and Aspergillus parasiticus. All four species are classified to the A. flavus group. Strains of the A. flavus group are characterized by a high degree of morphological similarity. Koji mold species are generally perceived of as being nontoxigenic, whereas wild molds...... are associated with the carcinogenic aflatoxins. Thus, reliable identification of individual strains is very important for application purposes. This review considers the pheno- and genotypic markers used in the classification of A. flavus group strains and specifically in the identification of A...

  18. Genomic sequences of Aspergillus flavus accessions in Georgia USA

    Data.gov (United States)

    US Agency for International Development — The data was produced as part of the Feed the Future Innovation Lab for Collaborative Research on Peanut Productivity and Aflatoxin Control (the Peanut &...

  19. Aspergillus pragensis sp nov discovered during molecular reidentification of clinical isolates belonging to Aspergillus section Candidi

    Czech Academy of Sciences Publication Activity Database

    Hubka, Vít; Lysková, P.; Frisvad, J.C.; Peterson, S.W.; Skořepová, M.; Kolařík, Miroslav

    2014-01-01

    Roč. 52, č. 6 (2014), s. 565-576. ISSN 1369-3786 R&D Projects: GA MŠk(CZ) EE2.3.20.0055; GA MŠk(CZ) EE2.3.30.0003 Institutional support: RVO:61388971 Keywords : Aspergillus candidus * Aspergillus tritici * antifungal susceptibility testing Subject RIV: EE - Microbiology, Virology Impact factor: 2.335, year: 2014

  20. The Production of Itaconic Acid from Sweet Potato Peel Using Aspergillus niger and Aspergillus terreus

    OpenAIRE

    OMOJASOLA PATRICIA FOLAKEMI; ADENIRAN EUNICE ADERONKE

    2014-01-01

    Accumulation of large quantities of agricultural residues results in deterioration of the environment and biomass loss which could be processed to yield value-added products like fuels and a variety of acids. The quest for a solution led to the fermentation of Ipomoea batatas using fungi. Aspergillus niger (ATCC 16404) and Aspergillus terreus (ATCC 20542) were used to ferment sweet potato peel (SPP), an agro-based waste. The physico-chemical analysis of the SPP was carried out. SPP was dried...

  1. A new approach for molecular cloning in cyanobacteria: cloning of an anacystis nidulans met gene using a Tn 907-induced mutant

    NARCIS (Netherlands)

    Tandeau de Marsac, N.; Borrias, W.E.; Kuhlemeijer, C.J.; Castets, A.M.; Arkel, G.A. van; Hondel, C.A.M.J.J. van den

    1982-01-01

    A new strategy for molecular cloning in the cyanobacterium Anacystis nidulans R-2 is described. This strategy involved the use of a transposon and was developed for the cloning of a gene encoding methionine biosynthesis. A met::Tn 901 mutant was isolated. Chromosomal DNA fragments were cloned in the

  2. Study of effect ultraviolet radiation on Aspergillus Flavus and Aspergillus Parasiticus

    International Nuclear Information System (INIS)

    In this article the results of ultraviolet radiation effects on Aspergillus Flavus and Aspergillus parasiticus to reach the quality control standards are presented. The purpose was to test the effect of ultraviolet radiation in 254 nanometer wavelength for fungi decontamination with respect to the exposure time of radiation and the distance between samples and radiation source. The ultraviolet radiation effects on plates containing Aspergillus Flavus and Aspergillus Parasiticus fungi were studied in the exposure time duration of 30, to 360 seconds of a fixed distance, and also for variable distances from 10 to 40 cm at a given exposure time. It is shown that in the exposure time of more than 360 second the ultraviolet radiation exposure highly decreases the number of Aspergillus Flavus and Aspergillus Parasiticus fungi colonies. By reducing the distance, the number of colonies decreases and it is minimized at a 10 cm distance in the time exposure of 360 second. The above results show that the ultraviolet radiation is an effective method for food decontamination and can be used in industry

  3. Taxonomic Characterization and Secondary Metabolite Profiling of Aspergillus Section Aspergillus Contaminating Feeds and Feedstuffs

    Science.gov (United States)

    Greco, Mariana; Kemppainen, Minna; Pose, Graciela; Pardo, Alejandro

    2015-01-01

    Xerophilic fungal species of the genus Aspergillus are economically highly relevant due to their ability to grow on low water activity substrates causing spoilage of stored goods and animal feeds. These fungi can synthesize a variety of secondary metabolites, many of which show animal toxicity, creating a health risk for food production animals and to humans as final consumers, respectively. Animal feeds used for rabbit, chinchilla and rainbow trout production in Argentina were analysed for the presence of xerophilic Aspergillus section Aspergillus species. High isolation frequencies (>60%) were detected in all the studied rabbit and chinchilla feeds, while the rainbow trout feeds showed lower fungal charge (25%). These section Aspergillus contaminations comprised predominantly five taxa. Twenty isolates were subjected to taxonomic characterization using both ascospore SEM micromorphology and two independent DNA loci sequencing. The secondary metabolite profiles of the isolates were determined qualitatively by HPLC-MS. All the isolates produced neoechinulin A, 17 isolates were positive for cladosporin and echinulin, and 18 were positive for neoechinulin B. Physcion and preechinulin were detected in a minor proportion of the isolates. This is the first report describing the detailed species composition and the secondary metabolite profiles of Aspergillus section Aspergillus contaminating animal feeds. PMID:26364643

  4. New species in Aspergillus section Terrei

    DEFF Research Database (Denmark)

    Samson, R. A.; Peterson, S. W.; Frisvad, Jens Christian;

    2011-01-01

    Section Terrei of Aspergillus was studied using a polyphasic approach including sequence analysis of parts of the beta-tubulin and calmodulin genes and the ITS region, macro- and micromorphological analyses and examination of extrolite profiles to describe three new species in this section. Based...

  5. Organic acid production by Aspergillus niger

    DEFF Research Database (Denmark)

    Jongh, Wian de

    2006-01-01

    . Specielt Aspergillus niger er interessant i forbindelse med produktion af organiske syrer, idet denne organisme tolerer lavt pH, kan give høje produktudbytter, og kan give høje produktiviteter som allerede illustreret i anvendelsen af denne organisme i produktionen af citronsyre. Disse faktorer gør A...

  6. Phylogeny and subgeneric taxonomy of Aspergillus

    DEFF Research Database (Denmark)

    Peterson, S.W.; Varga, Janos; Frisvad, Jens Christian;

    2008-01-01

    The phylogeny of the genus Aspergillus and its teleomorphs is discussed based on multilocus sequence data. DNA sequence analysis was used to formulate a nucleotide sequence framework of the genus and to analyze character changes in relationship to the phylogeny hypothesized from the DNA sequence...

  7. Proteomic analysis of the secretory response of Aspergillus niger to D-maltose and D-xylose

    OpenAIRE

    Ferreira de Oliveira, J.M.P.; Passel,; Schaap, P.J.; Graaff, de, F.M.

    2011-01-01

    Fungi utilize polysaccharide substrates through extracellular digestion catalyzed by secreted enzymes. Thus far, protein secretion by the filamentous fungus Aspergillus niger has mainly been studied at the level of individual proteins and by genome and transcriptome analyses. To extend these studies, a complementary proteomics approach was applied with the aim to investigate the changes in secretome and microsomal protein composition resulting from a shift to a high level secretion condition....

  8. Proteomic Analysis of the Secretory Response of Aspergillus niger to D-Maltose and D-Xylose

    OpenAIRE

    Ferreira de Oliveira, José Miguel P.; van Passel, Mark W. J.; Schaap, Peter J; de Graaff, Leo H

    2011-01-01

    Fungi utilize polysaccharide substrates through extracellular digestion catalyzed by secreted enzymes. Thus far, protein secretion by the filamentous fungus Aspergillus niger has mainly been studied at the level of individual proteins and by genome and transcriptome analyses. To extend these studies, a complementary proteomics approach was applied with the aim to investigate the changes in secretome and microsomal protein composition resulting from a shift to a high level secretion condition....

  9. Identifying and characterizing the most significant β-glucosidase of the novel species Aspergillus saccharolyticus

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, Anette; Ahring, Birgitte K.; Lubeck, Mette; Ubhayasekera, Wimal; Bruno, Kenneth S.; Culley, David E.; Lubeck, Peter S.

    2012-08-20

    A newly discovered fungal species, Aspergillus saccharolyticus, was found to produce a culture broth rich in beta-glucosidase activity. In this present work, the main beta-glucosidase of A. saccharolyticus responsible for the efficient hydrolytic activity was identified, isolated, and characterized. Ion exchange chromatography was used to fractionate the culture broth, yielding fractions with high beta-glucosidase activity and only one visible band on an SDS-PAGE gel. Mass spectrometry analysis of this band gave peptide matches to beta-glucosidases from aspergilli. Through a PCR approach using degenerate primers and genome walking, a 2919 base pair sequence encoding the 860 amino acid BGL1 polypeptide was determined. BGL1 of A. saccharolyticus has 91% and 82% identity with BGL1 from Aspergillus aculeatus and BGL1 from Aspergillus niger, respectively, both belonging to Glycoside hydrolase family 3. Homology modeling studies suggested beta-glucosidase activity with preserved retaining mechanism and a wider catalytic pocket compared to other beta-glucosidases. The bgl1 gene was heterologously expressed in Trichoderma reesei QM6a, purified, and characterized by enzyme kinetics studies. The enzyme can hydrolyze cellobiose, pNPG, and cellodextrins. The enzyme showed good thermostability, was stable at 50°C, and at 60°C it had a half-life of approximately 6 hours.

  10. Bisulfite sequencing reveals that Aspergillus flavus holds a hollow in DNA methylation

    DEFF Research Database (Denmark)

    Liu, Si-Yang; Lin, Jian-Qing; Wu, Hong-Long;

    2012-01-01

    Aspergillus flavus first gained scientific attention for its production of aflatoxin. The underlying regulation of aflatoxin biosynthesis has been serving as a theoretical model for biosynthesis of other microbial secondary metabolites. Nevertheless, for several decades, the DNA methylation status......, one of the important epigenomic modifications involved in gene regulation, in A. flavus remains to be controversial. Here, we applied bisulfite sequencing in conjunction with a biological replicate strategy to investigate the DNA methylation profiling of A. flavus genome. Both the bisulfite sequencing...... detection in species with low DNA methylation may serve as a reference for later scientific investigations in other hypomethylated species....

  11. Two novel species of Aspergillus section Nigri from Thai coffee beans

    DEFF Research Database (Denmark)

    Noonim, Paramee; Mahakarnchanakul, Warapa; Varga, Janos; Frisvad, Jens Christian; Samson, Robert A.

    2008-01-01

    Two novel species of Aspergillus section Nigri from Thai coffee beans are described as Aspergillus aculeatinus sp. nov. and Aspergillus sclerotiicarbonarius sp. nov. Their taxonomic status was determined using a polyphasic taxonomic approach with phenotypic (morphology and extrolite profiles) and...

  12. Two novel species of Aspergillus section Nigri from Thai coffee beans

    DEFF Research Database (Denmark)

    Noonim, Paramee; Mahakarnchanakul, Warapa; Varga, Janos;

    2008-01-01

    Two novel species of Aspergillus section Nigri from Thai coffee beans are described as Aspergillus aculeatinus sp. nov. and Aspergillus sclerotiicarbonarius sp. nov. Their taxonomic status was determined using a polyphasic taxonomic approach with phenotypic (morphology and extrolite profiles...

  13. Phylogeny, identification and nomenclature of the genus Aspergillus

    DEFF Research Database (Denmark)

    Samson, R.A.; Visagie, C.M.; Houbraken, J.;

    2014-01-01

    Aspergillus comprises a diverse group of species based on morphological, physiological and phylogenetic characters, which significantly impact biotechnology, food production, indoor environments and human health. Aspergillus was traditionally associated with nine teleomorph genera, but phylogenetic...... data suggest that together with genera such as Polypaecilum, Phialosimplex, Dichotomomyces and Cristaspora, Aspergillus forms a monophyletic clade closely related to Penicillium. Changes in the International Code of Nomenclature for algae, fungi and plants resulted in the move to one name per species......, meaning that a decision had to be made whether to keep Aspergillus as one big genus or to split it into several smaller genera. The International Commission of Penicillium and Aspergillus decided to keep Aspergillus instead of using smaller genera. In this paper, we present the arguments for this decision...

  14. Aspergillus triggers phenazine production in Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Jensen, Britt Guillaume; Jelsbak, Lars; Søndergaard, Ib;

    Objectives: Pseudomonas aeruginosa is an opportunistic human pathogen, commonly infecting cystic fibrosis (CF) patients. Aspergilli, especially Aspergillus fumigatus, are also frequently isolated from CF patients. Our aim was to examine the possible interaction between P. aeruginosa and different...... the contact area of A. niger, A. flavus, A. oryzae, but not A. fumigatus. In addition, other metabolites with UV chromophores similar to the phenazines were only found in the contact zone between Aspergillus and Pseudomonas. No change in secondary metabolite profiles were seen for the Aspergilli, when...... comparing with or without the presence of Pseudomonas. Conclusion: All Aspergilli tested, with the exception of A. fumigatus, triggered the upregulation of phenazine-1-carboxamide and phenazine-1-carboxylic acid production by P. aeruginosa. Surprisingly no changes in secondary metabolite profiles were...

  15. Aspergillus species: An emerging pathogen in onychomycosis among diabetics

    Directory of Open Access Journals (Sweden)

    T M Wijesuriya

    2015-01-01

    Full Text Available Introduction: Approximately, 33% patients with diabetes are afflicted with onychomycosis. In the past, nondermatophyte molds have been regarded as opportunistic pathogens; recently, Aspergillus species are considered as emerging pathogens of toenail infections. In Sri Lanka, the prevalence of Aspergillus species in onychomycosis among diabetics is not well documented. Objective: To determine the proportion of Aspergillus onychomycosis, risk factors and knowledge among diabetics. Materials and Methods: This was descriptive cross-sectional study. Three hundred diabetic patients were included. Clinical examinations of patients' toenails were performed by a clinical microbiologist. Laboratory identification was done, and pathogens were identified to the species level by morpho-physiological methods. All inferential statistics were tested at P age group. In men, Aspergillus onycomycosis was seen in 82%. Among patients who had Aspergillus nail infection, 114 (63% had diabetes for a period of > years. Among patients who were engaged in agricultural activities, 77% were confirmed to have infected nails due to Aspergillus species. Conclusion: Aspergillus niger was the most common pathogen isolated from toenail infection. Aspergillus species should be considered as an important pathogen in toenail onychomycosis in diabetic patients. Risk factors associated with Aspergillus onychomycosis were age, gender, duration of diabetes, length of exposure to fungi, and occupation.

  16. Increased enzyme production under liquid culture conditions in the industrial fungus Aspergillus oryzae by disruption of the genes encoding cell wall α-1,3-glucan synthase.

    Science.gov (United States)

    Miyazawa, Ken; Yoshimi, Akira; Zhang, Silai; Sano, Motoaki; Nakayama, Mayumi; Gomi, Katsuya; Abe, Keietsu

    2016-09-01

    Under liquid culture conditions, the hyphae of filamentous fungi aggregate to form pellets, which reduces cell density and fermentation productivity. Previously, we found that loss of α-1,3-glucan in the cell wall of the fungus Aspergillus nidulans increased hyphal dispersion. Therefore, here we constructed a mutant of the industrial fungus A. oryzae in which the three genes encoding α-1,3-glucan synthase were disrupted (tripleΔ). Although the hyphae of the tripleΔ mutant were not fully dispersed, the mutant strain did form smaller pellets than the wild-type strain. We next examined enzyme productivity under liquid culture conditions by transforming the cutinase-encoding gene cutL1 into A. oryzae wild-type and the tripleΔ mutant (i.e. wild-type-cutL1, tripleΔ-cutL1). A. oryzae tripleΔ-cutL1 formed smaller hyphal pellets and showed both greater biomass and increased CutL1 productivity compared with wild-type-cutL1, which might be attributable to a decrease in the number of tripleΔ-cutL1 cells under anaerobic conditions. PMID:27442340

  17. CYANOBACTERIAL BIOMASS AS N-SUPPLEMENT TO OIL PALM EMPTY FRUIT BUNCH (OPEFB FIBRE FOR IMPROVEMENT OF CELLULASE PRODUCTION BY ASPERGILLUS TERREUS IN SUBMERGED FERMENTATION

    Directory of Open Access Journals (Sweden)

    Mahdi Shahriarinour

    2011-03-01

    Full Text Available The possibility of using dry biomass of a cyanobacterium, Anacystis nidulans, as nitrogen source supplement for improvement of cellulase production by Aspergillus terreus was studied in submerged fermentation using oil palm empty fruit bunch (OPEFB fibre as a carbon source. For comparison, four other nitrogen sources (ammonium sulphate, urea, peptone, and yeast extract were also tested. Growth and cellulase production were greatly enhanced in fermentation using biomass of cyanobacterium as the nitrogen source. The use of cyanobacterial biomass as a nitrogen source also reduced the inhibitory effect of high concentrations of CaCl2 to growth of A. terreus and cellulase production. The addition of 0.3 g L-1 CaCl2 to the medium containing OPEFB fibre and cyanobacterial biomass further enhanced the cellulase production, though growth remained unchanged. The final FPase, CMCase, and β-glucosidase obtained in fermentation using 10 g L-1 OPEFB fibre and 6 g/L cynaobacterial biomass with the addition of 3 mM CaCl2 was 0.97 U mL-1, 14.1 U mL-1, and 10.4 U mL-1, respectively.

  18. SYNTHESIS OF COPPER NANOPARTICLES BY ASPERGILLUS SPECIES

    OpenAIRE

    Kantabathini Venkata Pavani; Nandigam Srujana; Guntur Preethi; Tandale Swati

    2013-01-01

    Recent developments in the biosynthesis of nanomaterials have demonstrated the important role of microorganisms in nanotechnology. The organisms show a unique potential in environmentally friendly production and accumulation of nanoparticles with different shapes and sizes. The present study proposed a green process for synthesis of copper nanoparticles using Aspergillus species. Syntheses of copper nanoparticles were characterized by UV-visible spectroscopy. The extracellular synthesis of co...

  19. SYNTHESIS OF COPPER NANOPARTICLES BY ASPERGILLUS SPECIES

    Directory of Open Access Journals (Sweden)

    Kantabathini Venkata Pavani

    2013-06-01

    Full Text Available Recent developments in the biosynthesis of nanomaterials have demonstrated the important role of microorganisms in nanotechnology. The organisms show a unique potential in environmentally friendly production and accumulation of nanoparticles with different shapes and sizes. The present study proposed a green process for synthesis of copper nanoparticles using Aspergillus species. Syntheses of copper nanoparticles were characterized by UV-visible spectroscopy. The extracellular synthesis of copper nanoparticles was characterized by scanning electron microscopy and Transmission electron microscopy.

  20. Degradation of melanin by Aspergillus fumigatus.

    OpenAIRE

    Luther, J P; Lipke, H.

    1980-01-01

    A strain of Aspergillus fumigatus from composted coffee and garden wastes utilized natural deproteinized insect, banana, hair, octopus, and synthetic tyrosine and dopa melanins as sole sources of carbon. With a sucrose supplement, degradation was essentially complete after 50 days in Czapek medium pH 6.5 at 30 degrees C. The catabolic rate differed for each substrate pigment, as did the molecular weight distribution of products accumulating in the medium. After incubation with L-[U-14C]melani...

  1. Aspergillus bertholletius sp. nov. from Brazil Nuts

    OpenAIRE

    Taniwaki, Marta H.; Pitt, John I.; Iamanaka, Beatriz T.; Sartori, Daniele; Copetti, Marina V.; Balajee, Arun; Fungaro, Maria Helena P.; Frisvad, Jens Christian

    2012-01-01

    During a study on the mycobiota of brazil nuts (Bertholletia excelsa) in Brazil, a new Aspergillus species, A. bertholletius, was found, and is described here. A polyphasic approach was applied using morphological characters, extrolite data as well as partial beta-tubulin, calmodulin and ITS sequences to characterize this taxon. A. bertholletius is represented by nineteen isolates from samples of brazil nuts at various stages of production and soil close to Bertholletia excelsa trees. The fol...

  2. Pectinolytic activity of Aspergillus section Nigri strains

    OpenAIRE

    Maciel, M. H. C.; Ottoni, C. A.; Santos, C.; Moreira, K.; Lima, Nelson; Motta, Cristina Souza

    2012-01-01

    Pectinases are a heterogeneous group of related enzymes that hydrolyze pectic substances present mostly in plants. Pectinases are produced by plants, fungi, yeasts and bacteria. Filamentous fungi are good producers of pectinolytic enzymes (e.g., exopolygalacturonase (exo-PG) and endopolygalacturonase (endo-PG) and Aspergillus niger is the most commonly used fungal species for industrial production of pectinolytic enzymes. The application of pectinolytic enzymes plays an importa...

  3. Functional analysis of Abp1p-interacting proteins involved in endocytosis of the MCC component in Aspergillus oryzae.

    Science.gov (United States)

    Matsuo, Kento; Higuchi, Yujiro; Kikuma, Takashi; Arioka, Manabu; Kitamoto, Katsuhiko

    2013-07-01

    We have investigated the functions of three endocytosis-related proteins in the filamentous fungus Aspergillus oryzae. Yeast two-hybrid screening using the endocytic marker protein AoAbp1 (A.oryzae homolog of Saccharomyces cerevisiae Abp1p) as a bait identified four interacting proteins named Aip (AoAbp1 interacting proteins). In mature hyphae, EGFP (enhanced green fluorescent protein) fused to Aips colocalized with AoAbp1 at the hyphal tip region and the plasma membrane, suggesting that Aips function in endocytosis. aipA is a putative AAA ATPase and its function has been dissected (Higuchi et al., 2011). aipB, the homolog of A. nidulans myoA, encodes an essential class I myosin and its conditional mutant showed a germination defect. aipC and aipD do not contain any recognizable domains except some proline-rich regions which may interact with two SH3 (Src homology 3) domains of AoAbp1. Neither aipC nor aipD disruptants showed any defects in their growth, but the aipC disruptant formed less conidia compared with the control strain. In addition, the aipC disruptant was resistant to the triazole antifungal drugs that inhibit ergosterol biosynthesis. Although no aip disruptants showed any defects in the uptake of the fluorescent dye FM4-64, the endocytosis of the arginine permease AoCan1, one of the MCC (membrane compartment of Can1p) components, was delayed in both aipC and aipD disruptants. In A. oryzae, AoCan1 localized mainly at the plasma membrane in the basal region of hyphae, suggesting that different endocytic mechanisms exist in apical and basal regions of highly polarized cells. PMID:23597630

  4. Transcriptome analysis of Aspergillus niger grown on sugarcane bagasse

    Directory of Open Access Journals (Sweden)

    Goldman Gustavo H

    2011-10-01

    Full Text Available Abstract Background Considering that the costs of cellulases and hemicellulases contribute substantially to the price of bioethanol, new studies aimed at understanding and improving cellulase efficiency and productivity are of paramount importance. Aspergillus niger has been shown to produce a wide spectrum of polysaccharide hydrolytic enzymes. To understand how to improve enzymatic cocktails that can hydrolyze pretreated sugarcane bagasse, we used a genomics approach to investigate which genes and pathways are transcriptionally modulated during growth of A. niger on steam-exploded sugarcane bagasse (SEB. Results Herein we report the main cellulase- and hemicellulase-encoding genes with increased expression during growth on SEB. We also sought to determine whether the mRNA accumulation of several SEB-induced genes encoding putative transporters is induced by xylose and dependent on glucose. We identified 18 (58% of A. niger predicted cellulases and 21 (58% of A. niger predicted hemicellulases cellulase- and hemicellulase-encoding genes, respectively, that were highly expressed during growth on SEB. Conclusions Degradation of sugarcane bagasse requires production of many different enzymes which are regulated by the type and complexity of the available substrate. Our presently reported work opens new possibilities for understanding sugarcane biomass saccharification by A. niger hydrolases and for the construction of more efficient enzymatic cocktails for second-generation bioethanol.

  5. Plant-like biosynthesis of isoquinoline alkaloids in Aspergillus fumigatus.

    Science.gov (United States)

    Baccile, Joshua A; Spraker, Joseph E; Le, Henry H; Brandenburger, Eileen; Gomez, Christian; Bok, Jin Woo; Macheleidt, Juliane; Brakhage, Axel A; Hoffmeister, Dirk; Keller, Nancy P; Schroeder, Frank C

    2016-06-01

    Natural product discovery efforts have focused primarily on microbial biosynthetic gene clusters (BGCs) containing large multimodular polyketide synthases and nonribosomal peptide synthetases; however, sequencing of fungal genomes has revealed a vast number of BGCs containing smaller NRPS-like genes of unknown biosynthetic function. Using comparative metabolomics, we show that a BGC in the human pathogen Aspergillus fumigatus named fsq, which contains an NRPS-like gene lacking a condensation domain, produces several new isoquinoline alkaloids known as the fumisoquins. These compounds derive from carbon-carbon bond formation between two amino acid-derived moieties followed by a sequence that is directly analogous to isoquinoline alkaloid biosynthesis in plants. Fumisoquin biosynthesis requires the N-methyltransferase FsqC and the FAD-dependent oxidase FsqB, which represent functional analogs of coclaurine N-methyltransferase and berberine bridge enzyme in plants. Our results show that BGCs containing incomplete NRPS modules may reveal new biosynthetic paradigms and suggest that plant-like isoquinoline biosynthesis occurs in diverse fungi. PMID:27065235

  6. A novel non-thermostable deuterolysin from Aspergillus oryzae.

    Science.gov (United States)

    Maeda, Hiroshi; Katase, Toru; Sakai, Daisuke; Takeuchi, Michio; Kusumoto, Ken-Ichi; Amano, Hitoshi; Ishida, Hiroki; Abe, Keietsu; Yamagata, Youhei

    2016-09-01

    Three putative deuterolysin (EC 3.4.24.29) genes (deuA, deuB, and deuC) were found in the Aspergillus oryzae genome database ( http://www.bio.nite.go.jp/dogan/project/view/AO ). One of these genes, deuA, was corresponding to NpII gene, previously reported. DeuA and DeuB were overexpressed by recombinant A. oryzae and were purified. The degradation profiles against protein substrates of both enzymes were similar, but DeuB showed wider substrate specificity against peptidyl MCA-substrates compared with DeuA. Enzymatic profiles of DeuB except for thermostability also resembled those of DeuA. DeuB was inactivated by heat treatment above 80° C, different from thermostable DeuA. Transcription analysis in wild type A. oryzae showed only deuB was expressed in liquid culture, and the addition of the proteinous substrate upregulated the transcription. Furthermore, the NaNO3 addition seems to eliminate the effect of proteinous substrate for the transcription of deuB. PMID:27050120

  7. Bisulfite sequencing reveals that Aspergillus flavus holds a hollow in DNA methylation.

    Directory of Open Access Journals (Sweden)

    Si-Yang Liu

    Full Text Available Aspergillus flavus first gained scientific attention for its production of aflatoxin. The underlying regulation of aflatoxin biosynthesis has been serving as a theoretical model for biosynthesis of other microbial secondary metabolites. Nevertheless, for several decades, the DNA methylation status, one of the important epigenomic modifications involved in gene regulation, in A. flavus remains to be controversial. Here, we applied bisulfite sequencing in conjunction with a biological replicate strategy to investigate the DNA methylation profiling of A. flavus genome. Both the bisulfite sequencing data and the methylome comparisons with other fungi confirm that the DNA methylation level of this fungus is negligible. Further investigation into the DNA methyltransferase of Aspergillus uncovers its close relationship with RID-like enzymes as well as its divergence with the methyltransferase of species with validated DNA methylation. The lack of repeat contents of the A. flavus' genome and the high RIP-index of the small amount of remanent repeat potentially support our speculation that DNA methylation may be absent in A. flavus or that it may possess de novo DNA methylation which occurs very transiently during the obscure sexual stage of this fungal species. This work contributes to our understanding on the DNA methylation status of A. flavus, as well as reinforces our views on the DNA methylation in fungal species. In addition, our strategy of applying bisulfite sequencing to DNA methylation detection in species with low DNA methylation may serve as a reference for later scientific investigations in other hypomethylated species.

  8. Systemic analysis of the response of Aspergillus niger to ambient pH

    DEFF Research Database (Denmark)

    Andersen, Mikael Rørdam; Lehmann, Linda Olkjær; Nielsen, Jens

    2009-01-01

    highly efficient acidification as well as production process applicable knowledge on the transcriptional regulation of pH response in the industrially important A. niger. It has also made clear that filamentous fungi have evolved to employ several offensive strategies for out-competing rival organisms.......Background: The filamentous fungus Aspergillus niger is an exceptionally efficient producer of organic acids, which is one of the reasons for its relevance to industrial processes and commercial importance. While it is known that the mechanisms regulating this production are tied to the levels of...... ambient pH, the reasons and mechanisms for this are poorly understood. Methods: To cast light on the connection between extracellular pH and acid production, we integrate results from two genome-based strategies: A novel method of genome-scale modeling of the response, and transcriptome analysis across...

  9. Clonality and sex impact aflatoxigenicity in Aspergillus populations

    Science.gov (United States)

    Species in Aspergillus section Flavi commonly infect agricultural staples such as corn, peanuts, cottonseed, and tree nuts and produce an array of mycotoxins, the most potent of which are aflatoxins. Aspergillus flavus is the dominant aflatoxin-producing species in the majority of crops. Populatio...

  10. The current status of species recognition and identification in Aspergillus

    Science.gov (United States)

    The genus Aspergillus is a large economically important genus of fungi. In agriculture, some of the 250 species in this genus cause disease in plants and animals and some also produce poisons (mycotoxins) in foods and feeds. Aspergillus is a major killer of immunosuppressed people, such as diabeti...

  11. Aspergillus fumigatus conidial melanin modulates host cytokine response

    NARCIS (Netherlands)

    L.Y.A. Chai (Louis); M.G. Netea (Mihai); J. Sugui (Janyce); A.G. Vonk (Alieke); W.W.J. van de Sande (Wendy); A. Warris (Adilia); K.J. Kwon-Chung (Kyung); B. Jan Kullberg (Bart)

    2010-01-01

    textabstractMelanin biopigments have been linked to fungal virulence. Aspergillus fumigatus conidia are melanised and are weakly immunogenic. We show that melanin pigments on the surface of resting Aspergillus fumigatus conidia may serve to mask pathogen-associated molecular patterns (PAMPs)-induced

  12. Phylogeny, identification and nomenclature of the genus Aspergillus.

    Science.gov (United States)

    Samson, R A; Visagie, C M; Houbraken, J; Hong, S-B; Hubka, V; Klaassen, C H W; Perrone, G; Seifert, K A; Susca, A; Tanney, J B; Varga, J; Kocsubé, S; Szigeti, G; Yaguchi, T; Frisvad, J C

    2014-06-01

    Aspergillus comprises a diverse group of species based on morphological, physiological and phylogenetic characters, which significantly impact biotechnology, food production, indoor environments and human health. Aspergillus was traditionally associated with nine teleomorph genera, but phylogenetic data suggest that together with genera such as Polypaecilum, Phialosimplex, Dichotomomyces and Cristaspora, Aspergillus forms a monophyletic clade closely related to Penicillium. Changes in the International Code of Nomenclature for algae, fungi and plants resulted in the move to one name per species, meaning that a decision had to be made whether to keep Aspergillus as one big genus or to split it into several smaller genera. The International Commission of Penicillium and Aspergillus decided to keep Aspergillus instead of using smaller genera. In this paper, we present the arguments for this decision. We introduce new combinations for accepted species presently lacking an Aspergillus name and provide an updated accepted species list for the genus, now containing 339 species. To add to the scientific value of the list, we include information about living ex-type culture collection numbers and GenBank accession numbers for available representative ITS, calmodulin, β-tubulin and RPB2 sequences. In addition, we recommend a standard working technique for Aspergillus and propose calmodulin as a secondary identification marker. PMID:25492982

  13. Aspergillus brasiliensis sp. nov., a biseriate black Aspergillus species with world-wide distribution

    DEFF Research Database (Denmark)

    Varga, János; Kocsubé, Sándor; Tóth, Beáta;

    2007-01-01

    to produce ochratoxin A, kotanins, funalenone or pyranonigrins. The novel species was most closely related to A. niger, and was isolated from soil from Brazil, Australia, USA and The Netherlands, and from grape berries from Portugal. The type strain of Aspergillus brasiliensis sp. nov. is CBS 101740...

  14. Two novel aflatoxin-producing Aspergillus species from Argentinean peanuts

    DEFF Research Database (Denmark)

    Pildain, M.B.; Frisvad, Jens Christian; Vaamonde, G.; Cabral, D.; Varga, J.; Samson, R.A.

    2008-01-01

    (morphology and extrolite profiles) and molecular (beta-tubulin and calmodulin gene sequences) characters. A. minisclerotigenes resembles Aspergillus flavus and Aspergillus parvisclerotigenus in producing aflatoxins B-1 and B-2, cyclopiazonic acid, kojic acid and aspergillic acid, but in addition it produces......Two novel species from Aspergillus section Flavi from different species of Arachis (peanuts) in Argentina are described as Aspergillus arachidicola sp. nov. and Aspergillus minisclerotigenes sp. nov. Their novel taxonomic status was determined using a polyphasic taxonomic approach with phenotypic...... aflatoxins G(1) and G(2), aflavarins, aflatrem, aflavinines, parasiticolides and paspaline. This species also includes several isolates previously assigned to A. flavus group II and three Australian soil isolates. A. arachidicola produces aflatoxins B-1, B-2, G(1) and G(2), kojic acid, chrysogine and...

  15. Cloning and Characterization of the Aspergillus ochraceoroseus Aflatoxin Biosynthetic Gene Cluster

    Science.gov (United States)

    Production of the carcinogenic mycotoxin aflatoxin B1 has been reported from members of Aspergillus section Flavi, Aspergillus section Nidulantes, and a newly proposed section, Aspergillus section Ochraceorosei that consists of Aspergillus ochraceoroseus and the closely related A. rambellii. A. och...

  16. Aspergillus bertholletius sp. nov. from Brazil Nuts

    DEFF Research Database (Denmark)

    Taniwaki, Marta H.; Pitt, John I.; Iamanaka, Beatriz T.;

    2012-01-01

    During a study on the mycobiota of brazil nuts (Bertholletia excelsa) in Brazil, a new Aspergillus species, A. bertholletius, was found, and is described here. A polyphasic approach was applied using morphological characters, extrolite data as well as partial beta-tubulin, calmodulin and ITS...... sequences to characterize this taxon. A. bertholletius is represented by nineteen isolates from samples of brazil nuts at various stages of production and soil close to Bertholletia excelsa trees. The following extrolites were produced by this species: aflavinin, cyclopiazonic acid, kojic acid, tenuazonic...

  17. Production of amylases by Aspergillus tamarii

    OpenAIRE

    Moreira Fabiana Guillen; Lima Francieli Arrias de; Pedrinho Sophia Renata Fazzano; Lenartovicz Veridiana; Souza Cristina Giatti Marques de; Peralta Rosane Marina

    1999-01-01

    A strain of Aspergillus tamarii, a filamentous fungus isolated from soil, was able to produce both a-amylase and glucoamylase activities in mineral media supplemented with 1% (w/v) starch or maltose as the carbon source. Static cultivation led to significantly higher yields than those obtained using shaking culture. The production of amylases was tolerant to a wide range of initial culture pH values (from 4 to 10) and temperature (from 25 to 42oC). Two amylases, one a-amylase and one glucoamy...

  18. Aspergillus endophthalmitis in orthotopic liver transplantation

    Directory of Open Access Journals (Sweden)

    Hosseini Hamid

    2009-06-01

    Full Text Available In this report, we describe a patient with drug-induced liver failure who developed endogenous endophthalmitis after liver transplantation. Our patient′s clinical course was so fulminant that the eye was lost in less than 1 month, without any response to therapy. Recognition of this infection is important because many patients die of disseminated Aspergillus infection, which may be detected early with bedside funduscopic examination by an ophthalmologist. Probably if the patient had referred to us earlier, it may have been possible to save the eye.

  19. Scleral buckle infection with aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Bouhaimed Manal

    2008-01-01

    Full Text Available Purpose: To present a case of scleral buckle infection with Aspergillus flavus in a tertiary eye center in Saudi Arabia. Methods: A retrospective case report of a 28-year-old Saudi male who presented with a six-month history of conjunctival injection and discharge from the left eye which had undergone uncomplicated conventional retinal detachment surgery, at the King Khaled Eye Specialist Hospital in Riyadh, Saudi Arabia, in the form of cryopexy, subretinal fluid drainage and scleral buckle (grooved segmental sponge and circumferential band with sleeve for a macula on retinal detachment four years earlier. A diagnosis of infected extruded scleral buckle was made and the buckle was removed. Results: The infected scleral buckle was removed under local anesthesia with administration of sub-conjunctival irrigation of 50 mg solution of Vancomycin, and sub-conjunctival injection of 25mg of Vancomycin. Post operative microbiological studies revealed infection with silver staining of moderate Aspergillus flavus hyphae. Visual acuity of the left eye improved from 20/200 before surgery to 20/60 in the two years follow-up visit. Conclusion: This case report indicates the importance of considering infection with multiple organisms - including fungal ones - in cases of scleral buckle infections in our population.

  20. Aspergillus pneumonia in renal transplant recipients

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-dong; HU Xiao-peng; YIN Hang; WANG Wei; ZHANG Xin; MA Lin-lin; WANG Yong

    2008-01-01

    Background Filamentous fungal infections are associated with a high morbidity and mortality in solid organ transplants.The present study aimed to investigate the aspergillus pneumonia in renal transplant recipients, and its diagnosis as well as treatment.Methods Approximately 2000 cases of renal transplants were retrospectively studied and we focused on cases hospitalized during August 1, 2005 and February 1, 2007, as the study period. The clinical database and electronic records were analyzed. Recently published literature was reviewed.Results There was more diabetes and hypertension in the infected group than in the non-infected group (86% vs 62% and 57% vs 39%, respectively). Eighty-six percent of recipients from the infected group had delayed graft function. Seven cases with aspergillus pneumonia were identified based on either fungal culture or radiology. Of the 7 cases, 4 died in a few days after diagnosis. Liposomal amphotericin B was used as a first-line therapy.Conclusions Incidences of fungal infection are increasing among renal transplant recipients. Early diagnosis and treatment are critical steps in curing aspergillosis.

  1. Aspergillus in the lung: diverse and coincident forms

    International Nuclear Information System (INIS)

    Pulmonary disease caused by the fungus Aspergillus has traditionally been regarded as belonging to one of the following, apparently distinct, entities: saprophytic aspergilloma; allergic bronchopulmonary aspergillosis (ABPA); and invasive aspergillosis (IPA); which may be further categorised as angioinvasive, acute or chronic airway invasive [1]. It is not always obvious that there is overlap between these entities, and that in any given patient more than one Aspergillus-related pathological process can co-exist [2]. The aim of this article is to review the clinical and imaging features of the main categories of Aspergillus-related pulmonary disease and, in particular, to highlight the overlap between them. (orig.)

  2. Pulmonary hypersensitivity to Alternaria and Aspergillus in baker's asthma.

    Science.gov (United States)

    Klaustermeyer, W B; Bardana, E J; Hale, F C

    1977-05-01

    In two cases of baker's asthma pulmonary hypersensitivity was found to the fungi Alternaria and Aspergillus. Provocative bronchial challenge revealed a dual response; an immediate and an Arthus type hypersensitivity to Aspergillus in the first case. A primary binding assay revealed high titres of anti-Aspergillus antibody in the serum. In the second case intradermal and bronchial challenge suggested an immediate type I hypersensitivity response to Alternaria. The suspected organisms were present in the room air of the bakeries. It is suggested that an immunological response to these airborne fungi may have contributed to the pathogenesis of baker's asthma. PMID:561668

  3. Effect of gamma radiation on Aspergillus flavus and Aspergillus ochraceus ultrastructure and mycotoxin production

    International Nuclear Information System (INIS)

    The aim of this work was to study the effect of gamma radiation (2 kGy) on Aspergillus flavus and Aspergillus ochraceus ultrastructure. Moreover, the influence on aflatoxin B1 and ochratoxin A production was also observed. Irradiated A. flavus strain showed a dull orangish colony while control strain showed the typical green color. Minor differences were observed on stipes, metulae and conidia size between control and irradiated A. flavus and A. ochraceus strains. Irradiated fungi showed ultrastructural changes on cell wall, plasmalema and cytoplasm levels. The levels of mycotoxins produced by irradiated strains were two times greater than those produced by control strains. Successive transferences of irradiated strains on malt extract agar allowed the fungus to recuperate morphological characteristics. Although minor changes in the fungal morphology were observed, ultrastructural changes at cell wall level and the increase of mycotoxin production ability were observed. Inappropriate storage of irradiated food and feed would allow the development of potentially more toxicogenic fungal propagules.

  4. Effect of gamma radiation on Aspergillus flavus and Aspergillus ochraceus ultrastructure and mycotoxin production

    Science.gov (United States)

    Ribeiro, J.; Cavaglieri, L.; Vital, H.; Cristofolini, A.; Merkis, C.; Astoreca, A.; Orlando, J.; Carú, M.; Dalcero, A.; Rosa, C. A. R.

    2011-05-01

    The aim of this work was to study the effect of gamma radiation (2 kGy) on Aspergillus flavus and Aspergillus ochraceus ultrastructure. Moreover, the influence on aflatoxin B 1 and ochratoxin A production was also observed. Irradiated A. flavus strain showed a dull orangish colony while control strain showed the typical green color. Minor differences were observed on stipes, metulae and conidia size between control and irradiated A. flavus and A. ochraceus strains. Irradiated fungi showed ultrastructural changes on cell wall, plasmalema and cytoplasm levels. The levels of mycotoxins produced by irradiated strains were two times greater than those produced by control strains. Successive transferences of irradiated strains on malt extract agar allowed the fungus to recuperate morphological characteristics. Although minor changes in the fungal morphology were observed, ultrastructural changes at cell wall level and the increase of mycotoxin production ability were observed. Inappropriate storage of irradiated food and feed would allow the development of potentially more toxicogenic fungal propagules.

  5. Aspergillus pragensis sp nov discovered during molecular reidentification of clinical isolates belonging to Aspergillus section Candidi

    DEFF Research Database (Denmark)

    Lyskova, Pavlina; Hubka, Vit; Kolarik, Miroslav;

    2014-01-01

    The identity of nine clinical isolates recovered from Czech patients and presumptively identified as Aspergillus sp. section Candidi based on colony morphology was revised using sequences of beta-tubulin, calmodulin gene sequence, and internal transcribed spacer rDNA. Six isolates were from...... secondary metabolite analysis was also provided with comparison of metabolite spectrum to other species. Section Candidi now encompasses five species for which a dichotomous key based on colony characteristics is provided. All clinical isolates were tested for susceptibilities to selected antifungal agents...... suspected and proven onychomycosis, one from otitis externa, and two associated with probable invasive aspergillosis. The results showed that one Aspergillus candidus isolate was the cause of otitis externa, and both isolates obtained from sputa of patients with probable invasive aspergillosis were...

  6. A novel fungal fruiting structure formed by Aspergillus niger and Aspergillus carbonarius in grape berries.

    Science.gov (United States)

    Pisani, Cristina; Nguyen, Trang Thoaivan; Gubler, Walter Douglas

    2015-09-01

    Sour rot, is a pre-harvest disease that affects many grape varieties. Sour rot symptoms include initial berry cracking and breakdown of berry tissue. This is a disease complex with many filamentous fungi and bacteria involved, but is usually initiated by Aspergillus niger or Aspergillus carbonarius. Usually, by the time one sees the rot there are many other organisms involved and it is difficult to attribute the disease to one species. In this study two species of Aspergillus were shown to produce a previously unknown fruiting structure in infected berries. The nodulous morphology, bearing conidia, suggests them to be an 'everted polymorphic stroma'. This structure forms freely inside the berry pulp and assumes multiple shapes and sizes, sometimes sclerotium-like in form. It is composed of a mass of vegetative hyphae with or without tissue of the host containing spores or fruiting bodies bearing spores. Artificially inoculated berries placed in soil in winter showed the possible overwintering function of the fruiting body. Inoculated berry clusters on standing vines produced fruiting structures within 21 d post inoculation when wounds were made at veraison or after (July-September). Histological studies confirmed that the fruiting structure was indeed fungal tissue. PMID:26321727

  7. Extrolites of Aspergillus fumigatus and Other Pathogenic Species in Aspergillus Section Fumigati

    Science.gov (United States)

    Frisvad, Jens C.; Larsen, Thomas O.

    2016-01-01

    Aspergillus fumigatus is an important opportunistic human pathogen known for its production of a large array of extrolites. Up to 63 species have been described in Aspergillus section Fumigati, some of which have also been reliably reported to be pathogenic, including A. felis, A. fischeri, A. fumigatiaffinis, A. fumisynnematus, A. hiratsukae, A. laciniosus, A. lentulus, A. novofumigatus, A. parafelis, A. pseudofelis, A. pseudoviridinutans, A. spinosus, A. thermomutatus, and A. udagawae. These species share the production of hydrophobins, melanins, and siderophores and ability to grow well at 37°C, but they only share some small molecule extrolites, that could be important factors in pathogenicity. According to the literature gliotoxin and other exometabolites can be contributing factors to pathogenicity, but these exometabolites are apparently not produced by all pathogenic species. It is our hypothesis that species unable to produce some of these metabolites can produce proxy-exometabolites that may serve the same function. We tabulate all exometabolites reported from species in Aspergillus section Fumigati and by comparing the profile of those extrolites, suggest that those producing many different kinds of exometabolites are potential opportunistic pathogens. The exometabolite data also suggest that the profile of exometabolites are highly specific and can be used for identification of these closely related species. PMID:26779142

  8. GH11 xylanase from Emericella nidulans with low sensitivity to inhibition by ethanol and lignocellulose-derived phenolic compounds.

    Science.gov (United States)

    Silva, Caio de Oliveira Gorgulho; Aquino, Elaine Nascimento; Ricart, Carlos André Ornelas; Midorikawa, Gláucia Emy Okida; Miller, Robert Neil Gerard; Filho, Edivaldo Ximenes Ferreira

    2015-07-01

    An endo-β-1,4-xylanase (X22) was purified from crude extract of Emericella nidulans when cultivated on submerged fermentation using sugarcane bagasse as the carbon source. The purified protein was identified by mass spectrometry and was most active at pH and temperature intervals of 5.0-6.5 and 50-60°C, respectively. The enzyme showed half-lives of 40, 10 and 7 min at 28, 50 and 55°C, respectively, and pH 5.0. Apparent Km and Vmax values on soluble oat spelt xylan were 3.39 mg/mL and 230.8 IU/mg, respectively, while Kcat and Kcat/Km were 84.6 s(-1) and 25.0 s(-1) mg(-1) mL. Incubation with phenolic compounds showed that tannic acid and cinnamic acid had an inhibitory effect on X22 but no time-dependent deactivation. On the other hand, ferulic acid, 4-hydroxybenzoic acid, vanillin and p-coumaric acid did not show any inhibitory effect on X22 activity, although they changed X22 apparent kinetic parameters. Ethanol remarkably increased enzyme thermostability and apparent Vmax and Kcat values, even though the affinity and catalytic efficiency for xylan were lowered. PMID:26040589

  9. Nonfunctionality of Aspergillus sojae aflR in a Strain of Aspergillus parasiticus with a Disrupted aflR Gene

    OpenAIRE

    Takahashi, Tadashi; Chang, Perng-Kuang; Matsushima, Kenichiro; Yu, Jiujiang; Abe, Keietsu; Bhatnagar, Deepak; Cleveland, Thomas E.; Koyama, Yasuji

    2002-01-01

    Aspergillus sojae belongs to the Aspergillus section Flavi but does not produce aflatoxins. The functionality of the A. sojae aflR gene (aflRs) was examined by transforming it into an ΔaflR strain of A. parasiticus, derived from a nitrate-nonutilizing, versicolorin A (VERA)-accumulating strain. The A. parasiticus aflR gene (aflRp) transformants produced VERA, but the aflRs transformants did not. Even when aflRs was placed under the control of the amylase gene (amyB) promoter of Aspergillus or...

  10. Aspergillus antigen testing in bone marrow transplant recipients

    OpenAIRE

    Williamson, E; Oliver, D.; Johnson, E.; Foot, A.; D. Marks; Warnock, D.

    2000-01-01

    Aims—To assess the clinical usefulness of a commercial aspergillus antigen enzyme linked immunosorbent assay (ELISA) in the diagnosis of invasive aspergillosis (IA) in bone marrow transplant recipients, and to compare it with a commercial latex agglutination (LA) test.

  11. Septic arthritis due to tubercular and Aspergillus co-infection

    Directory of Open Access Journals (Sweden)

    Mukesh Kumar

    2016-01-01

    Full Text Available Aspergillus septic arthritis is a rare and serious medical and surgical problem. It occurs mainly in immunocompromised patients. Aspergillus fumigatus is the most common causative organism followed by Aspergillus flavus. The most common site affected is knee followed by shoulder, ankle, wrist, hip and sacroiliac joint. Debridement and voriconazole are primary treatment of articular aspergilosis. To the best of our knowledge, there are no reported cases of co-infection of tuberculosis (TB and Aspergillus infecting joints. We report a case of co-infection of TB and A. flavus of hip and knee of a 60-year-old male, with type 2 diabetes mellitus. He was treated with debridement, intravenous voriconazole, and antitubercular drugs.

  12. Polyphasic taxonomy of Aspergillus fumigatus and related species

    DEFF Research Database (Denmark)

    Hong, S.B.; Go, S.J.; Shin, H.D.;

    2005-01-01

    The variability within Aspergillus fumigalus Fresenius and related species was examined using macro-, micro-morphology, growth temperature regimes and extrolite patterns. In addition, DNA analyses including partial beta-tubulin, calmodulin and actin gene sequences were used. Detailed examination ...

  13. Nutrient environment influences competition among Aspergillus flavus genotypes

    Science.gov (United States)

    Structures of Aspergillus flavus populations, shaped by intraspecific competition, influence the incidences and severities of crop aflatoxin contamination. Competition for nutrients may be one factor modulating intraspecific interactions, but influences of specific types and concentrations of nutrie...

  14. Aspergillus niger contains the cryptic phylogenetic species A. awamori

    DEFF Research Database (Denmark)

    Perrone, Giancarlo; Stea, Gaetano; Epifani, Filomena;

    2011-01-01

    . Phylogenetic analyses of sequences generated from portions of three genes coding for the proteins β-tubulin (benA), calmodulin (CaM), and the translation elongation factor-1 alpha (TEF-1α) of a population of A. niger strains isolated from grapes in Europe revealed the presence of a cryptic phylogenetic species......Aspergillus section Nigri is an important group of species for food and medical mycology, and biotechnology. The Aspergillus niger ‘aggregate’ represents its most complicated taxonomic subgroup containing eight morphologically indistinguishable taxa: A. niger, Aspergillus tubingensis, Aspergillus...... mycotoxins ochratoxin A and fumonisin B2, and they also share the production of pyranonigrin A, tensidol B, funalenone, malformins, and naphtho-γ-pyrones. In addition, sequence analysis of four putative A. awamori strains from Japan, used in the koji industrial fermentation, revealed that none of these...

  15. Microbial transformation of curcumol by Aspergillus niger.

    Science.gov (United States)

    Chen, Li-Xia; Zhang, Hui; Zhao, Qian; Yin, Shi-Yu; Zhang, Zhong; Li, Tian-Xian; Qiu, Feng

    2013-02-01

    Curcumol is a representative index component for the quality control of the essential oil of Curcuma wenyujin Y.H. Chen et C. Ling, an antivirus and anticancer drug in China. Microbial transformation of curcumol (1) by Aspergillus niger AS 3.739 yielded two products. Their structures were elucidated as 3alpha-hydroxycurcumol (2) and 3alpha-(4'-methoxy-succinyloxy)-curcumol (3) by extensive spectroscopic methods including 2D-NMR and HRESI-MS. Among them, 3 is a new compound. Esterification of the substrate with succinic acid is a novel reaction in the field of microbial transformation of natural products. Compound 2, the major transformation product of 1, was a high regio- and stereo-specific hydroxylation product and showed significant antiviral effects. PMID:23513713

  16. Synthesis of lead nanoparticles by Aspergillus species.

    Science.gov (United States)

    Pavani, K V; Kumar, N Sunil; Sangameswaran, B B

    2012-01-01

    In the context of the current demand to develop green technologies in material synthesis, a natural process in the synthesis of lead particles by Aspergillus species to suit such technology is reported. The fungal strain was grown in medium containing different concentrations of lead (0.2-1.5 mM) to determine its resistance to heavy metals. The organism was found to utilize some mechanism and accumulate lead particles outside and inside the cell. The extracellular presence of lead particles in the range of 1.77-5.8 microm was characterized by scanning electron microscopy. The presence of particles of lead in the 5-20 nm size range was found on the cell surface, in the periplasmic space and in the cytoplasm and was analyzed by transmission electron microscopy. PMID:22708348

  17. Production of amylases by Aspergillus tamarii

    Directory of Open Access Journals (Sweden)

    Moreira Fabiana Guillen

    1999-01-01

    Full Text Available A strain of Aspergillus tamarii, a filamentous fungus isolated from soil, was able to produce both a-amylase and glucoamylase activities in mineral media supplemented with 1% (w/v starch or maltose as the carbon source. Static cultivation led to significantly higher yields than those obtained using shaking culture. The production of amylases was tolerant to a wide range of initial culture pH values (from 4 to 10 and temperature (from 25 to 42oC. Two amylases, one a-amylase and one glucoamylase, were separated by ion exchange chromatography. Both partially purified enzymes had optimal activities at pH values between 4.5 and 6.0 and were stable under acid conditions (pH 4.0-7.0. The enzymes exhibited optimal activities at temperatures between 50o and 60o C and were stable for more than ten hours at 55oC.

  18. Studies on Aspergillus Flavus Link. Isolated From Maize in Iran

    OpenAIRE

    Houshyar-Fard Mahmoud; Rouhani Hamid; Falahati-Rastegar Mahrokh; Mahdikhani-Moghaddam Esmat; Malekzadeh-Shafaroudi Saeed; Probst Claudia

    2014-01-01

    The Aspergillus flavus population structure from maize kernels was examined. During 2011, samples were collected from two main grain maize production areas in Iran (Fars and Ardebil provinces), shortly before harvest. One-hundred nine A. flavus isolates were recovered on Dichloran Rose Bengal Chloramphenicole (DRBC) agar and Aspergillus flavus/parasiticus medium (AFPA) and grouped into morphotypes and Vegetative Compatibility Groups (VCGs) based on morphological (e.g. sclerotia production), p...

  19. New ochratoxin A producing species of Aspergillus section Circumdati

    DEFF Research Database (Denmark)

    Frisvad, Jens Christian; Frank, J.M.; Houbraken, J.A.M.P.; Kuijpers, A.F.A.; Samson, R.A.

    Aspergillus section Circumdati contains species with yellow to ochre conidia and non-black sclerotia that produce at least one of the following extrolites: ochratoxins, penicillic acids, xanthomegnins or melleins. The exception to this is A. robustus, which produces black sclerotia, phototropic...... A: Aspergillus cretensis, A. flocculosus, A. pseudoelegans, A. roseoglobulosus, A. westerdijkiae, A. sulphurous, and Neopetromyces muricatus. Two species produce large or small amounts of ochratoxin A, but less consistently: A. ochraceus and A. sclerotiorum. Ochratoxin production in these species...

  20. Significance and occurrence of fumonisins from Aspergillus niger

    OpenAIRE

    Mogensen, Jesper Mølgaard; Nielsen, Kristian Fog; Larsen, Thomas Ostenfeld; Frisvad, Jens Christian

    2012-01-01

    Fumonisins is a well-studied group of mycotoxins, mainly produced in maize by Fusarium species. However with the recent discovery of a fumonisin production by Aspergillus niger, other food commodities are at risk, since A. niger is a ubiquitous contaminant of many food and feed products. The objective of this thesis was to determine the significance and occurrence of fumonisins from Aspergillus niger in food, the frequency of fumonisin production in A. niger isolates, as well as studies of th...

  1. Aspergillus Mycoviruses Are Targets and Suppressors of RNA Silencing▿ †

    OpenAIRE

    Hammond, T. M.; Andrewski, M. D.; Roossinck, M J; Keller, N P

    2007-01-01

    RNA silencing can function as a virus defense mechanism in a diverse range of eukaryotes, and many viruses are capable of suppressing the silencing machinery targeting them. However, the extent to which this occurs between fungal RNA silencing and mycoviruses is unclear. Here, three Aspergillus dsRNA mycoviruses were partially characterized, and their relationship to RNA silencing was investigated. Aspergillus virus 1816 is related to Agaricus bisporus white button mushroom virus 1 and suppre...

  2. Aspergillus fumigatus Conidial Melanin Modulates Host Cytokine Response

    OpenAIRE

    Chai, Louis; Netea, Mihai; SUGUI, JANYCE; Vonk, Alieke; van de Sande, Wendy; Warris, Adilia; Kwon-Chung, Kyung; Jan Kullberg, Bart

    2009-01-01

    textabstractMelanin biopigments have been linked to fungal virulence. Aspergillus fumigatus conidia are melanised and are weakly immunogenic. We show that melanin pigments on the surface of resting Aspergillus fumigatus conidia may serve to mask pathogen-associated molecular patterns (PAMPs)-induced cytokine response. The albino conidia induced significantly more proinflammatory cytokines in human peripheral blood mononuclear cells (PBMC), as compared to melanised wild-type conidia. Blocking ...

  3. Immobilization of Isolated Lipase From Moldy Copra (Aspergillus Oryzae)

    OpenAIRE

    Seniwati

    2012-01-01

    Enzyme immobilization is a recovery technique that has been studied in several years, using support as a media to help enzyme dissolutions to the reaction substrate. Immobilization method used in this study was adsorption method, using specific lipase from Aspergillus oryzae. Lipase was partially purified from the culture supernatant of Aspergillus oryzae. Enzyme was immobilized by adsorbed on silica gel. Studies on free and immobilized lipase systems for determination of op...

  4. Immobilization of Isolated Lipase From Moldy Copra (Aspergillus Oryzae)

    OpenAIRE

    Seniwati Dali; A. B. D. Rauf Patong; M.Noor Jalaluddin; Pirman; Baharuddin Hamzah

    2011-01-01

    Enzyme immobilization is a recovery technique that has been studied in several years, using support as a media to help enzyme dissolutions to the reaction substrate. Immobilization method used in this study was adsorption method, using specific lipase from Aspergillus oryzae. Lipase was partially purified from the culture supernatant of Aspergillus oryzae. Enzyme was immobilized by adsorbed on silica gel. Studies on free and immobilized lipase systems for determination of optimum pH, optimum ...

  5. Accessory enzymes from Aspergillus involved in xylan and pectin degradation

    OpenAIRE

    Vries, de, G.

    1999-01-01

    The xylanolytic and pectinolytic enzyme systems from Aspergillus have been the subject of study for many years. Although the main chain cleaving enzymes and their encoding genes have been studied in detail, little information is available about most of the accessory enzymes and their corresponding genes. This thesis describes the purification and characterisation of two accessory enzymes from Aspergillus , feruloyl esterase A (FaeA) andα-glucuronidase A (AguA), and the activities of these enz...

  6. Systems biology studies of Aspergilli - from sequence to science

    DEFF Research Database (Denmark)

    Andersen, Mikael Rørdam

    2008-01-01

    The recent dawn of the new biological mindset called systems biology has put forth a new way of analyzing and understanding biology. Carried by the notion that no element of a cell is an island, systems biology takes a holistic approach, and attempts to understand life as systems that have co...... transcriptomic to mention a few. The recent publication of the genome sequences of several filamentous fungi of the Aspergillus species (Aspergilli), has, along with the accumulation of years of reductionist studies, been a catalyst for the application of systems biology to this interesting group of fungi. Among...... the genome sequenced Aspergilli are a known human pathogen (Aspergillus fumigatus), a model organism for cellular mechanisms (Aspergillus nidulans) and two industrial workhorses (Aspergillus niger and Aspergillus oryzae). In the presented work, new analytical and computational tools have been designed...

  7. Utilization of Low-Cost Ellagitannins for Ellagic Acid Production and Antimicrobial Phenolics Enhancing By Aspergillus awamorii and Aspergillus oryzae

    International Nuclear Information System (INIS)

    Three fungal strains, Aspergillus awamorii A9, Aspergillus awamorii A23 and Aspergillus oryzae O2, were selected out of ten fungal strains for their activeness in converting pomegranate peel ellagitannins into ellagic acid. When pomegranate peel was fermented by Aspergillus awamorii A9, the highest yields of ellagic acid (7.93±0.23 mg/g solid substrate) and total soluble phenolics (14.61±0.36 mg/g solid substrate) were produced at 5 and 10 days of incubation, respectively. Also, blue berry pomace, red grape pomace, strawberry pomace were evaluated as low cost ellagitannin sources for ellagic acid and soluble phenolics production. The antimicrobial activity of soluble phenolics extracted from fermented pomegranate peel and strawberry pomace was tested against two food-borne pathogens (Escherichia coli and Salmonella typhimurium). This study also revealed that 3 kGy enhanced the activity of antimicrobial phenolics

  8. Identification and characterization of the polyketide synthase involved in ochratoxin A biosynthesis in Aspergillus carbonarius.

    Science.gov (United States)

    Gallo, Antonia; Knox, Benjamin P; Bruno, Kenneth S; Solfrizzo, Michele; Baker, Scott E; Perrone, Giancarlo

    2014-06-01

    Ochratoxin A (OTA) is a potent mycotoxin produced by Aspergillus and Penicillium species and is a common contaminant of a wide variety of food commodities, with Aspergillus carbonarius being the main producer of OTA contamination in grapes and wine. The molecular structure of OTA comprises a dihydroisocoumarin ring linked to phenylalanine and, as shown in different producing fungal species, a polyketide synthase (PKS) is a component of the OTA biosynthetic pathway. Similar to observations in other filamentous ascomycetes, the genome sequence of A. carbonarius contains a large number of genes predicted to encode PKSs. In this work a pks gene identified within the putative OTA cluster of A. carbonarius, designated as AcOTApks, was inactivated and the resulting mutant strain was unable to produce OTA, confirming the role of AcOTApks in this biosynthetic pathway. AcOTApks protein is characteristic of the highly reduced (HR)-PKS family, and also contains a putative methyltransferase domain likely responsible for the addition of the methyl group to the OTA polyketide structure. AcOTApks is different from the ACpks protein that we previously described in A. carbonarius, which showed an expression profile compatible with OTA production. We performed phylogenetic analyses of the β-ketosynthase and acyl-transferase domains of the OTA PKSs that had been identified and characterized in different OTA producing fungal species. The phylogenetic results were similar for both domains analyzed and showed that OTA PKS of A. carbonarius, Aspergillus niger and Aspergillus ochraceus clustered in a monophyletic group with 100% bootstrap support suggesting a common origin, while the other OTA PKSs analyzed were phylogenetically distant. A quantitative RT-PCR assay monitored AcOTApks expression during fungal growth and concomitant production of OTA by A. carbonarius in synthetic grape medium. A clear correlation between the expression profile of AcOTApks and kinetics of OTA production was

  9. Identification and characterization of the polyketide synthase involved in ochratoxin A biosynthesis in Aspergillus carbonarius

    Energy Technology Data Exchange (ETDEWEB)

    Gallo, Antonia; Knox, Benjamin P.; Bruno, Kenneth S.; Solfrizzo, Michele; Baker, Scott E.; Perrone, Giancarlo

    2014-06-02

    Ochratoxin A (OTA) is a potent mycotoxin produced by Aspergillus and Penicillium species and is a common contaminant of a wide variety of food commodities, with Aspergillus carbonarius being the main producer of OTA contamination in grapes and wine. The molecular structure of OTA is composed of a dihydroisocoumarin ring linked to phenylalanine and, as shown in different producing fungal species, a polyketide synthase (PKS) is a component of the OTA biosynthetic pathway. Similar to observations in other filamentous ascomycetes, the genome sequence of A. carbonarius contains a large number of genes predicted to encode PKSs. In this work a pks gene identified within the putative OTA cluster of A. carbonarius, designated as AcOTApks, was inactivated and the resulting mutant strain was unable to produce OTA, confirming the role of AcOTApks in this biosynthetic pathway. AcOTApks protein is characteristic of the highly reduced (HR)-PKS family, and also contains a putative methyltransferase domain likely responsible for the addition of the methyl group to the OTA polyketide structure. AcOTApks is different from the ACpks protein that we previously described which showed an expression profile compatible with OTA production. We performed phylogenetic analyses of the β-ketosynthase and acyl-transferase domains of the OTA PKSs which had been identified and characterized in different OTA producing fungal species. The phylogenetic results were similar for both the two domains analyzed and showed that OTA PKS of A. carbonarius, Aspergillus niger, and Aspergillus ochraceus clustered in a monophyletic group with 100% bootstrap support suggesting a common origin, while the other OTA PKSs analyzed were phylogenetically distant. A qRT-PCR assay monitored AcOTApks expression during fungal growth and concomitant production of OTA by A. carbonarius in synthetic grape medium. A clear correlation between the expression profile of AcOTApks and kinetics of OTA production was observed with

  10. Estimating microalgae Synechococcus nidulans daily biomass concentration using neuro-fuzzy network Estimador neuro-fuzzy de concentração diária de biomassa da microalga Synechococcus nidulans

    Directory of Open Access Journals (Sweden)

    Vitor Badiale Furlong

    2013-02-01

    Full Text Available In this study, a neuro-fuzzy estimator was developed for the estimation of biomass concentration of the microalgae Synechococcus nidulans from initial batch concentrations, aiming to predict daily productivity. Nine replica experiments were performed. The growth was monitored daily through the culture medium optic density and kept constant up to the end of the exponential phase. The network training followed a full 3³ factorial design, in which the factors were the number of days in the entry vector (3,5 and 7 days, number of clusters (10, 30 and 50 clusters and internal weight softening parameter (Sigma (0.30, 0.45 and 0.60. These factors were confronted with the sum of the quadratic error in the validations. The validations had 24 (A and 18 (B days of culture growth. The validations demonstrated that in long-term experiments (Validation A the use of a few clusters and high Sigma is necessary. However, in short-term experiments (Validation B, Sigma did not influence the result. The optimum point occurred within 3 days in the entry vector, 10 clusters and 0.60 Sigma and the mean determination coefficient was 0.95. The neuro-fuzzy estimator proved a credible alternative to predict the microalgae growth.Neste trabalho, foi construído um estimador neuro-fuzzy da concentração de biomassa da microalga Synechococcus nidulans a partir de concentrações iniciais da batelada, visando possibilitar a predição da produtividade. Nove experimentos em réplica foram realizados. O crescimento foi acompanhado diariamente pela transmitância do meio e mantido até o final da fase exponencial de crescimento. O treinamento das redes ocorreu segundo delineamento experimental 3³, os fatores foram o número de dias no vetor de entrada (3, 5 e 7 dias, o número de clusters (10, 30 e 50 clusters e o valor de abrandamento do filtro interno (Sigma (0,30, 0,45 e 0,60. A variável resposta foi o somatório do erro quadrático das validações. Estas possuíam 24 (A

  11. Aproximación genético-bioquímica al estudio de la asimilación de nitrato en la cianobacteria "Anacystis nidulans R2"

    OpenAIRE

    Madueño Albi, Francisco

    1987-01-01

    Tras mutagénesis con transposón se han aislado 19 estirpes de la Cianobacteria Anacystis nidulans R2 incapaces de crecer en medio con nitrato como única fuente de nitrógeno. Se distinguen tres diferentes fenotipos en relación a la a ... ctividad de las enzimas implicadas en la reducción del nitrato. La estirpe FM16 muestra tanto actividad nitrato reductasa como actividad nitrito reductasa FM2 carece de la actividad nitrito reductasa y las restantes 16 estirpes carecen de la actividad nitrat...

  12. A modified recombineering protocol for the genetic manipulation of gene clusters in Aspergillus fumigatus.

    Directory of Open Access Journals (Sweden)

    Laura Alcazar-Fuoli

    Full Text Available Genomic analyses of fungal genome structure have revealed the presence of physically-linked groups of genes, termed gene clusters, where collective functionality of encoded gene products serves a common biosynthetic purpose. In multiple fungal pathogens of humans and plants gene clusters have been shown to encode pathways for biosynthesis of secondary metabolites including metabolites required for pathogenicity. In the major mould pathogen of humans Aspergillus fumigatus, multiple clusters of co-ordinately upregulated genes were identified as having heightened transcript abundances, relative to laboratory cultured equivalents, during the early stages of murine infection. The aim of this study was to develop and optimise a methodology for manipulation of gene cluster architecture, thereby providing the means to assess their relevance to fungal pathogenicity. To this end we adapted a recombineering methodology which exploits lambda phage-mediated recombination of DNA in bacteria, for the generation of gene cluster deletion cassettes. By exploiting a pre-existing bacterial artificial chromosome (BAC library of A. fumigatus genomic clones we were able to implement single or multiple intra-cluster gene replacement events at both subtelomeric and telomere distal chromosomal locations, in both wild type and highly recombinogenic A. fumigatus isolates. We then applied the methodology to address the boundaries of a gene cluster producing a nematocidal secondary metabolite, pseurotin A, and to address the role of this secondary metabolite in insect and mammalian responses to A. fumigatus challenge.

  13. Neopetromyces gen. nov and an overview of teleomorphs of Aspergillus subgenus Circumdati

    DEFF Research Database (Denmark)

    Frisvad, Jens Christian; Samson, R. A.

    2000-01-01

    Species in the anamorph genus Aspergillus are associated with several teleomorphic genera in the Eurotiales and the most important mycotoxin producers are concentrated in Aspergillus subgenus Circumdati. A new genus, Neopetromyces, is proposed for the recently described Petromyces muricatus, beca...

  14. The potential impact of the pulmonary microbiome on immunopathogenesis of Aspergillus-related lung disease

    NARCIS (Netherlands)

    Kolwijck, E.; Veerdonk, F.L. van de

    2014-01-01

    Aspergillosis is an infection or allergic response caused by fungi of the genus Aspergillus. The most common forms of aspergillosis are allergic bronchopulmonary aspergillosis, chronic pulmonary aspergillosis, and invasive pulmonary aspergillosis. Aspergillus also plays an important role in fungal s

  15. Overexpression of protein disulfide isomerase in Aspergillus.

    Science.gov (United States)

    El-Adawi, H; Khanh, N Q; Gassen, H

    2000-10-01

    One of the major problems with the production of biotechnologically valuable proteins has been the purification of the product. For Escherichia coli and Saccharomyces cerevisiae, there are several techniques for the purification of intracellular proteins, but these are time consuming and often result in poor yields. Purification can be considerably facilitated, if the product is secreted from the host cell. In the work presented, we have constructed an expression vector (pSGNH2) for the secretion of protein disulfide isomerase (PDI; EC 5.3.4.1) from Aspergillus niger, in which the retention signal His-Asp-Glu-Leu (H-D-E-L) was modified to Ala-Leu-Glu-Gln (A-L-E-Q) via the polymerase chain reaction (PCR) method. The PDI gene was placed under the control of the A. oryzae alpha-amylase promoter. This expression vector was transformed into A. niger NRRL3, resulting in PDI secretion into the medium. The catalytic activity of overexpressed PDI from A. niger was indistinguishable from that of PDI isolated from bovine liver. With further strain improvement and optimization of culture conditions, it could be possible to raise the PDI production to the bioprocessing scale. PMID:10977899

  16. Fingernail Onychomycosis Due to Aspergillus niger.

    Science.gov (United States)

    Kim, Dong Min; Suh, Moo Kyu; Ha, Gyoung Yim; Sohng, Seung Hyun

    2012-11-01

    Onychomycosis is usually caused by dermatophytes, but some species of nondermatophytic molds and yeasts are also associated with nail invasion. Aspergillus niger is a nondermatophytic mold which exists as an opportunistic filamentous fungus in all environments. Here, we report a case of onychomycosis caused by A. niger in a 66-year-old female. The patient presented with a black discoloration and a milky white base and onycholysis on the proximal portion of the right thumb nail. Direct microscopic examination of scrapings after potassium hydroxide (KOH) preparation revealed dichotomous septate hyphae. Repeated cultures on Sabouraud's dextrose agar (SDA) without cycloheximide produced the same black velvety colonies. No colony growth occurred on SDA with cycloheximide slants. Biseriate phialides covering the entire vesicle with radiate conidial heads were observed on the slide culture. The DNA sequence of the internal transcribed spacer region of the clinical sample was a 100% match to that of A. niger strain ATCC 16888 (GenBank accession number AY373852). A. niger was confirmed by KOH mount, colony identification, light microscopic morphology, and DNA sequence analysis. The patient was treated orally with 250 mg terbinafine daily and topical amorolfine 5% nail lacquer for 3 months. As a result, the patient was completely cured clinically and mycologically. PMID:23197914

  17. Ultrasonographic findings of aspergillus bursitis in a patient with a renal transplantation: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Byeong Seong; Yang, Myeon Jun; Kim, Young Min; Youm, Yoon Seok; Choi, Seong Hoon; Park, Sung Bin; Jeong, Ae Kyung [University of Ulsan College of Medicine, Ulsan University Hospital, Ulsan (Korea, Republic of)

    2008-04-15

    Aspergillus bursitis is an uncommon condition demonstrated as a nonspecific soft tissue mass. To our knowledge, the ultrasonographic findings of aspergillus bursitis in immunocompromised patients have not been previously reported. Here, we report a case of aspergillus bursitis in a renal transplant recipient, accompanied by the associated ultrasonographic findings.

  18. Ultrasonographic findings of aspergillus bursitis in a patient with a renal transplantation: a case report

    International Nuclear Information System (INIS)

    Aspergillus bursitis is an uncommon condition demonstrated as a nonspecific soft tissue mass. To our knowledge, the ultrasonographic findings of aspergillus bursitis in immunocompromised patients have not been previously reported. Here, we report a case of aspergillus bursitis in a renal transplant recipient, accompanied by the associated ultrasonographic findings

  19. Involvement of the opportunistic pathogen Aspergillus tubingensis in osteomyelitis of the maxillary bone: a case report

    Directory of Open Access Journals (Sweden)

    Bathoorn Erik

    2013-02-01

    Full Text Available Abstract Background Aspergillus tubingensis is a black Aspergillus belonging to the Aspergillus section Nigri, which includes species that morphologically resemble Aspergillus niger. Recent developments in species determination have resulted in clinical isolates presumed to be Aspergillus niger being reclassified as Aspergillus tubingensis by sequencing. We present a report of a patient with an osteomyelitis of the maxillary bone with a probable invasive Aspergillus tubingensis infection. Case presentation We describe an immune compromised patient suffering from osteomyelitis of the maxillary bone after tooth extraction. The osteomyelitis probably resulted in dentogenic pansinusitis presenting as an acute ethmoiditis. Histologic examination of biopsy samples showed osteomyelitis, and inflammation of the surrounding connective tissue. Cultures of the alveolar wound grew Aspergillus tubingensis. The patient was treated with liposomal amphoterocin B, which was changed to oral treatment with voriconazole based on susceptibility testing (MIC for voriconazole was 1 μg/ml. Conclusion This case shows that Aspergillus tubingensis may have the potential to cause severe invasive infections in immunocompromised hosts. A larger proportion of Aspergillus tubingensis isolates are less susceptible to azoles compared to Aspergillus niger. Therefore, correct species identification and susceptibility testing is crucial for the choice of anti-fungal treatment, screening of azole resistance, and characterization of the pathogenic potential of the various species within Aspergillus section Nigri.

  20. Effect of gamma radiation on Aspergillus flavus and Aspergillus ochraceus ultrastructure and mycotoxin production

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, J. [Departamento de Microbiologia e Inmunologia Veterinaria, Universidad Federal Rural de Rio de Janeiro (UFRRJ) (Brazil); Cavaglieri, L., E-mail: lcavaglieri@arnet.com.a [Departamento de Microbiologia e Inmunologia, Universidad Nacional de Rio Cuarto (UNRC), Rio Cuarto, Cordoba (Argentina); Member of Consejo Nacional de Investigaciones Cientificas y Tecnologicas (CIC-CONICET) (Argentina); Vital, H. [Centro Tecnologico do Exercito (CTEx), Secao de Defesa Nuclear, Rio de Janeiro (Brazil); Cristofolini, A.; Merkis, C. [Departamento de Microscopia Electronica, Universidad Nacional de Rio Cuarto. Ruta 36 km 601 (5800) Rio Cuarto (Argentina); Astoreca, A. [Departamento de Microbiologia e Inmunologia, Universidad Nacional de Rio Cuarto (UNRC), Rio Cuarto, Cordoba (Argentina); Member of Consejo Nacional de Investigaciones Cientificas y Tecnologicas (CIC-CONICET) (Argentina); Orlando, J.; Caru, M. [Departamento de Ciencias Ecologicas, Facultad de Ciencias, Universidad de Chile, Santiago (Chile); Dalcero, A. [Departamento de Microbiologia e Inmunologia, Universidad Nacional de Rio Cuarto (UNRC), Rio Cuarto, Cordoba (Argentina); Member of Consejo Nacional de Investigaciones Cientificas y Tecnologicas (CIC-CONICET) (Argentina); Rosa, C.A.R. [Departamento de Microbiologia e Inmunologia Veterinaria, Universidad Federal Rural de Rio de Janeiro (UFRRJ) (Brazil); Member of Consejo Nacional de Pesquisas (CNPq) (Brazil)

    2011-05-15

    The aim of this work was to study the effect of gamma radiation (2 kGy) on Aspergillus flavus and Aspergillus ochraceus ultrastructure. Moreover, the influence on aflatoxin B{sub 1} and ochratoxin A production was also observed. Irradiated A. flavus strain showed a dull orangish colony while control strain showed the typical green color. Minor differences were observed on stipes, metulae and conidia size between control and irradiated A. flavus and A. ochraceus strains. Irradiated fungi showed ultrastructural changes on cell wall, plasmalema and cytoplasm levels. The levels of mycotoxins produced by irradiated strains were two times greater than those produced by control strains. Successive transferences of irradiated strains on malt extract agar allowed the fungus to recuperate morphological characteristics. Although minor changes in the fungal morphology were observed, ultrastructural changes at cell wall level and the increase of mycotoxin production ability were observed. Inappropriate storage of irradiated food and feed would allow the development of potentially more toxicogenic fungal propagules.

  1. Transcriptomic profiling of Aspergillus flavus in response to 5-azacytidine.

    Science.gov (United States)

    Lin, Jian-Qing; Zhao, Xi-Xi; Zhi, Qing-Qing; Zhao, Ming; He, Zhu-Mei

    2013-07-01

    Aspergillus flavus is a common saprophyte and opportunistic pathogen producing aflatoxin (AF) and many other secondary metabolites. 5-Azacytidine (5-AC), a derivative of the nucleoside cytidine, is widely used for studies in epigenetics and cancer biology as an inactivator of DNA methyltransferase and is also used for studying secondary metabolism in fungi. Our previous studies showed that 5-AC affects development and inhibits AF production in A. flavus, and that A. flavus lacks DNA methylation. In this study, an RNA-Seq approach was applied to explore the mechanism of 5-AC's effect on A. flavus. We identified 240 significantly differentially expressed (Q-value<0.05) genes after 5-AC treatment, including two backbone genes respectively in secondary metabolite clusters #27 and #35. These two clusters are involved in development or survival of sclerotia. GO functional enrichment analysis showed that these significantly differentially expressed genes were mainly involved in catalytic activity and proteolytic functions. The expressed transcripts of most genes in the AF biosynthetic gene cluster in A. flavus showed no significant changes after treatment with 5-AC and were expressed at low levels, and the transcription regulator genes aflR and aflS in this cluster did not show differential expression relative to the sample without 5-AC treatment. We found that the veA gene, which encodes protein bridges VelB and LaeA, decreased profoundly the expressed transcripts, and brlA, which encodes an early regulator of development, increased its transcripts in A. flavus after 5-AC treatment. Our data support a model whereby 5-AC affects development through increasing the expression of brlA by depressing the expression of veA and AF production through suppressing veA expression and dysregulating carboxypeptidase activity, which then prevents the aflatoxisomes (vesicles) from performing their normal function in AF formation. Furthermore, the suppressed veA expression weakens or

  2. Electrochemical monitoring of citric acid production by Aspergillus niger

    International Nuclear Information System (INIS)

    Highlights: • Citric acid fermentation process (production) by Aspergillus niger. • Qualitative/quantitative monitoring of standard culture and culture infected with yeast. • Electronic tongue based on potentiometric and voltammetric sensors. • Evaluation of the progress and the correctness of the fermentation process. • The highest classification abilities of the hybrid electronic tongue. - Abstract: Hybrid electronic tongue was developed for the monitoring of citric acid production by Aspergillus niger. The system based on various potentiometric/voltammetric sensors and appropriate chemometric techniques provided correct qualitative and quantitative classification of the samples collected during standard Aspergillus niger culture and culture infected with yeast. The performance of the proposed approach was compared with the monitoring of the fermentation process carried out using classical methods. The results obtained proved, that the designed hybrid electronic tongue was able to evaluate the progress and correctness of the fermentation process

  3. Electrochemical monitoring of citric acid production by Aspergillus niger

    Energy Technology Data Exchange (ETDEWEB)

    Kutyła-Olesiuk, Anna; Wawrzyniak, Urszula E.; Ciosek, Patrycja; Wróblewski, Wojciech, E-mail: wuwu@ch.pw.edu.pl

    2014-05-01

    Highlights: • Citric acid fermentation process (production) by Aspergillus niger. • Qualitative/quantitative monitoring of standard culture and culture infected with yeast. • Electronic tongue based on potentiometric and voltammetric sensors. • Evaluation of the progress and the correctness of the fermentation process. • The highest classification abilities of the hybrid electronic tongue. - Abstract: Hybrid electronic tongue was developed for the monitoring of citric acid production by Aspergillus niger. The system based on various potentiometric/voltammetric sensors and appropriate chemometric techniques provided correct qualitative and quantitative classification of the samples collected during standard Aspergillus niger culture and culture infected with yeast. The performance of the proposed approach was compared with the monitoring of the fermentation process carried out using classical methods. The results obtained proved, that the designed hybrid electronic tongue was able to evaluate the progress and correctness of the fermentation process.

  4. Variability in Galactomannan detection by platelia Aspergillus EIA™ according to the Aspergillus species Variabilidade na detecção de galactomanana pelo Platelia Aspergillus EIA® de acordo com a espécie de Aspergillus

    Directory of Open Access Journals (Sweden)

    Melissa Orzechowski Xavier

    2013-06-01

    Full Text Available Here we investigate the extent to which different Aspergillus species release galactomannan (GM in vitro. Marked variability was observed in GM reactivity between and within Aspergillus species, with A. terreus strains showing the highest GM indexes. The in vivo significance of these findings remains to be determined.O estudo objetivou investigar a liberação in vitro de galactomanana (GM em distintas espécies patogênicas de fungos do gênero Aspergillus. Grande variabilidade foi detectada tanto intra quanto inter espécies, sendo as cepas da espécie A. terreus relacionadas aos maiores índices de GM detectados. O significado in vivo destes achados permanece em aberto, porém merece investigação.

  5. Phosphate solubilizing ability of two Arctic Aspergillus niger strains

    Directory of Open Access Journals (Sweden)

    Shiv Mohan Singh,

    2011-06-01

    Full Text Available Many filamentous fungi were isolated from the soils of Ny-Ålesund, Spitsbergen, Svalbard, and were screened in vitro for their phosphate solubilizing ability. Two strains of Aspergillus niger showed good tricalcium phosphate (TCP solubilizing ability in Pikovskaya's medium. The TCP solubilization index was calculated at varying levels of pH and temperatures. The ability of Aspergillus niger strain-1 to solubilize and release inorganic-P was 285 µg ml–1, while Aspergillus niger strain-2 solubilized 262 µg ml–1 from 0.5% TCP after seven days. This is the first report of TCP solubilization by Arctic strains that may serve as very good phosphate solubilizers in the form of biofertilizer.

  6. Heterologous expression of Aspergillus terreus fructosyltransferase in Kluyveromyces lactis.

    Science.gov (United States)

    Spohner, Sebastian C; Czermak, Peter

    2016-06-25

    Fructo-oligosaccharides are prebiotic and hypocaloric sweeteners that are usually extracted from chicory. They can also be produced from sucrose using fructosyltransferases, but the only commercial enzyme suitable for this purpose is Pectinex Ultra, which is produced with Aspergillus aculeatus. Here we used the yeast Kluyveromyces lactis to express a secreted recombinant fructosyltransferase from the inulin-producing fungus Aspergillus terreus. A synthetic codon-optimised version of the putative β-fructofuranosidase ATEG 04996 (XP 001214174.1) from A. terreus NIH2624 was secreted as a functional protein into the extracellular medium. At 60°C, the purified A. terreus enzyme generated the same pattern of oligosaccharides as Pectinex Ultra, but at lower temperatures it also produced oligomers with up to seven units. We achieved activities of up to 986.4U/mL in high-level expression experiments, which is better than previous reports of optimised Aspergillus spp. fermentations. PMID:27084521

  7. Aspergillus sellar abscess: Case report and review of the literature

    Directory of Open Access Journals (Sweden)

    Hao Li

    2008-01-01

    Full Text Available Aspergillus sellar abscess is a very rare form of fungal infections of the central nervous system (CNS. In this report, we describe the successful treatment of a patient with aspergillus sellar abscess. A 65-year-old woman presented with headache, nasal discharge and decreased visual acuity. The diagnosis of sellar mass was made on the basis of magnetic resonance imaging (MRI examination. The computed tomography (CT scan revealed sellar enlargement and sellar floor bony destruction. After hospitalization the patient underwent transsphenoidal surgery. Histopathological examination of the sellar mass revealed aspergillosis. Postoperatively, amphotericine-B and itraconazole therapy was started. During a six-month follow-up, the patient′s headache and inertia disappeared, visual acuity improved. Aspergillus sellar abscess must be considered in the differential diagnosis of a sellar mass. The correct diagnosis of pituitary aspergillosis can only be achieved by histopathological examination. Surgical intervention and antifungal therapy should be considered the optimal treatment.

  8. Biosorption potency of Aspergillus niger for removal of chromium (VI).

    Science.gov (United States)

    Srivastava, Shaili; Thakur, Indu Shekhar

    2006-09-01

    Aspergillus niger isolated from soil and effluent of leather tanning mills had higher activity to remove chromium. The potency of Aspergillus niger was evaluated in shake flask culture by absorption of chromium at pH 6 and temperature 30 degrees C. The results of the study indicated removal of more than 75% chromium by Aspergillus niger determined by diphenylcarbazide colorimetric assay and atomic absorption spectrophotometry after 7 days. Study of microbial Cr(VI) reduction and identification of reduction intermediates has been hindered by the lack of analytical techniques that can identify the oxidation state with subcellular spatial resolution. Therefore, removal of chromium was further substantiated by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX), which indicated an accumulation of chromium in the fungal mycelium. PMID:16874547

  9. Acute community acquired Aspergillus pneumonia in a presumed immunocompetent host

    Science.gov (United States)

    Sridhar, Varun; Rajagopalan, Natarajan; C, Shivaprasad; Patil, Mahantesh; Varghese, Jaicob

    2012-01-01

    Infection from Aspergillus results in a wide range of diseases from simple Aspergillus pneumonia to fatal invasive Aspergillosis. Though the fungus is known to predominantly affect the immunocompromised host, it has also been known to cause acute pneumonia in immunocompetent hosts which is invariably fatal. It presents as an acute pneumonia with bilateral chest infiltrates on radiograph. Early clinical suspicion and microbiological identification by measures such as broncho alveolar lavage and initiation of therapy with voricanozole significantly increase the chances of survival. In this article the authors discuss a case of acute community acquired Aspergillus pneumonia in an immunocompetent host who survived due to early identification and prompt treatment with appropriate antifungal medication. PMID:22605848

  10. A G-Protein β Subunit Required for Sexual and Vegetative Development and Maintenance of Normal Gα Protein Levels in Neurospora crassa

    OpenAIRE

    Yang, Qi; Poole, Sheven I.; Borkovich, Katherine A.

    2002-01-01

    The genome of the filamentous fungus Neurospora crassa contains a single gene encoding a heterotrimeric G-protein β subunit, gnb-1. The predicted GNB-1 protein sequence is most identical to Gβ proteins from the filamentous fungi Cryphonectria parasitica and Aspergillus nidulans. N. crassa GNB-1 is also 65% identical to the human GNB-1 protein but only 38 and 45% identical to Gβ proteins from budding and fission yeasts. Previous studies in animal and fungal systems have elucidated phenotypes o...

  11. Polyphasic taxonomy of Aspergillus section Fumigati and its teleomorph Neosartorya

    Directory of Open Access Journals (Sweden)

    S.W. Peterson

    2007-12-01

    Full Text Available The taxonomy of Aspergillus section Fumigati with its teleomorph genus Neosartorya is revised. The species concept is based on phenotypic (morphology and extrolite profiles and molecular (β-tubulin and calmodulin gene sequences characters in a polyphasic approach. Four new taxa are proposed: N. australensis N. ferenczii, N. papuaensis and N. warcupii. All newly described and accepted species are illustrated. The section consists of 33 taxa: 10 strictly anamorphic Aspergillus species and 23 Neosartorya species. Four other Neosartorya species described previously were not available for this monograph, and consequently are relegated to the category of doubtful species

  12. Experimental study of Aspergillus flavus fungus from uranium mines

    International Nuclear Information System (INIS)

    Cultivation is discussed of fungus strain Aspergillus flavus obtained from materials from uranium mines. It was found that an addition of 0.6 g of uranium in form of uranyl acetate or of 0.6 g of thorium in form on thorium nitrate in 1000 ml of the standard medium had stimulating effects on the growth and sporulation of Aspergillus flavus. Irradiating the cultivated fungus through a polyethylene foil did not show a stimulating effect. It is stated that uranium and its daughters must be directly present in the culture medium for their stimulating effect on growth and sporulation to manifest itself. (H.S.)

  13. New and revisited species in Aspergillus section Nigri

    DEFF Research Database (Denmark)

    Varga, J.; Frisvad, Jens Christian; Kocsube, S.;

    2011-01-01

    based on either beta-tubulin or calmodulin sequence data. Aspergillus eucalypticola produced pyranonigrin A, funalenone, aurasperone B and other naphtho-gamma-pyrones. Aspergillus neoniger is also a biseriate species isolated from desert sand in Namibia, and mangrove water in Venezuela, which produces...... and A. awamori are also detailed. Although these species differ in their occurrence and several physiological means (elastase activities, abilities to utilise 2-deoxy-D-glucose as sole carbon source), our data indicate that only molecular approaches including sequence analysis of calmodulin or beta...

  14. [Investigation of the relation between pigment composition and CO2 exchange in the blue-green alga anacystis nidulans].

    Science.gov (United States)

    Döhler, G; Przybylla, K R

    1970-06-01

    Changes in culture conditions caused strong changes in the pigment composition in the blue-green alga Anacystis nidulans. Under "normal" illumination (white light; 0.6·10(3) erg/cm(2)·sec) the relation between the amounts of chlorophyll a and phycocyanin was 1:6.6. In a high light intensity (20.8·10(3) erg/cm(2)·sec) the phycocyanin content was reduced and the relations thus changed to 1:1.9. Growing the algae in red light of high intensity (20·10(3) erg/cm(2)·sec) increased the phycocyanin content; the chlorophyll a: phycocyanin relation was then 1:12.1.The action spectrum of apparent photosynthesis showed a minimum at 473 nm in all three cultures. The maximum of photosynthesis in low light cultures fell in the absorption region of phycocyanin at 621 nm. The action spectrum of the red light culture showed a reduced rate of photosynthesis in the same region. The strong light culture had an action spectrum similar to that of the red light culture with a maximum at 651 nm. The differing action spectrum of the low light culture may be a result of interruption in the energy transfer from phycocyanin to chlorophyll a within pigment system II.The transients of CO2 exchange are independent of the pigment composition. Two different types of transients were found depending on the wavelength of the incident light. In red light of 550-650 nm a higher stationary rate was reached after a maximum of photosynthesis at the beginning of the illumination period. In blue and far red light a lower rate was found after the first maximum. Following a illumination period in blue or far red light a CO2 evolution in the dark was observed. On the other hand, this CO2 evolution was not found after illumination with red light. These effects are possiblt caused by a decarboxylation reaction (photorespiration) which occurs only in blue and far red light. PMID:24500744

  15. Antifungal Effects of Thyme, Agastache and Satureja Essential Oils on Aspergillus fumigatus, Aspergillus flavus and Fusarium solani

    Directory of Open Access Journals (Sweden)

    Karim Mardani

    2010-09-01

    Full Text Available Growth inhibition of Aspergillus fumigatus,Aspergillus flavus and Fusarum solani exposed to the essential oils including Thyme, Agastache and Satureja were studied. Disc Diffusion Method was used to evaluate the fungal growth inhibitory effects of the essential oils. Minimal inhibitory concentration (MIC and minimal fungicidal concentration (MFC of the oils were determined and compared with each other. The results showed that all three essential oils examined, had antifungal effects against three fungi species. The MIC data revealed that Thyme oil was the most effective essential oil with the MIC of 62.5 μl ml-1.

  16. Bola fúngica por Aspergillus fumigatus em cavidade pleural Aspergillus fumigatus fungus ball in the pleural cavity

    OpenAIRE

    Luciana Silva Guazzelli; Cecília Bittencourt Severo; Leonardo Santos Hoff; Geison Leonardo Fernandes Pinto; José Jesus Camargo; Luiz Carlos Severo

    2012-01-01

    OBJETIVO: Relatar os casos de 6 pacientes com bola fúngica (BF) na cavidade pleural por Aspergillus fumigatus. MÉTODOS: Entre 1980 e 2009, foram diagnosticados 391 pacientes com BF aspergilar no Complexo Hospitalar Santa Casa de Porto Alegre (RS). O diagnóstico de BF na cavidade pleural foi definido com exames de imagem demonstrando derrame e espessamento pleural com nível líquido; exame micológico direto demonstrando hifas septadas, consistentes com Aspergillus sp.; e cultura positiva para A...

  17. The Production of Itaconic Acid from Sweet Potato Peel Using Aspergillus niger and Aspergillus terreus

    Directory of Open Access Journals (Sweden)

    OMOJASOLA PATRICIA FOLAKEMI

    2014-12-01

    Full Text Available Accumulation of large quantities of agricultural residues results in deterioration of the environment and biomass loss which could be processed to yield value-added products like fuels and a variety of acids. The quest for a solution led to the fermentation of Ipomoea batatas using fungi. Aspergillus niger (ATCC 16404 and Aspergillus terreus (ATCC 20542 were used to ferment sweet potato peel (SPP, an agro-based waste. The physico-chemical analysis of the SPP was carried out. SPP was dried, ground, pre-treated with alkali and steam, re-dried and used as substrate in media containing mineral salt medium and inocula of A. niger and A. terreus. Fermentation was submerged at pH 5.0; 10% substrate concentration; 10 mL inocula size; temperature 250 C for five days with carboxylmethylcellulose (CMC as control. Optimization experiments were conducted by varying fermentation parameters. Results of physico-chemical analysis revealed carbohydrate 65.9%; sugars 22.60%; protein 5.38%; fibre 3.48%; fat 4.0% ash 4.02% and moisture 8.13%. Itaconic acid yield of 67.67+1.20 mg mL-1 and 70.67+2.60 mg mL-1 produced by A. niger and A. terreus from SPP respectively. The CMC yielded 3.00 +0.6 mg mL-1. Results of the optimization experiments showed higher yields of itaconic acid by A. niger and A. terreus to 112.67+5.20 mg mL-1 and 115.67+5.30 mg mL-1 from SPP respectively at pH 4.0; 10% substrate concentration; 5 mL inocula size on Day-5 of the fermentation. This represented an increase in product yield by both organisms and supports the potential use of this waste for the industrial production of itaconic acid.

  18. Metabolic activity in dormant conidia of Aspergillus niger and developmental changes during conidial outgrowth.

    Science.gov (United States)

    Novodvorska, Michaela; Stratford, Malcolm; Blythe, Martin J; Wilson, Raymond; Beniston, Richard G; Archer, David B

    2016-09-01

    The early stages of development of Aspergillus niger conidia during outgrowth were explored by combining genome-wide gene expression analysis (RNAseq), proteomics, Warburg manometry and uptake studies. Resting conidia suspended in water were demonstrated for the first time to be metabolically active as low levels of oxygen uptake and the generation of carbon dioxide were detected, suggesting that low-level respiratory metabolism occurs in conidia for maintenance. Upon triggering of spore germination, generation of CO2 increased dramatically. For a short period, which coincided with mobilisation of the intracellular polyol, trehalose, there was no increase in uptake of O2 indicating that trehalose was metabolised by fermentation. Data from genome-wide mRNA profiling showed the presence of transcripts associated with fermentative and respiratory metabolism in resting conidia. Following triggering of conidial outgrowth, there was a clear switch to respiration after 25min, confirmed by cyanide inhibition. No effect of SHAM, salicylhydroxamic acid, on respiration suggests electron flow via cytochrome c oxidase. Glucose entry into spores was not detectable before 1h after triggering germination. The impact of sorbic acid on germination was examined and we showed that it inhibits glucose uptake. O2 uptake was also inhibited, delaying the onset of respiration and extending the period of fermentation. In conclusion, we show that conidia suspended in water are not completely dormant and that conidial outgrowth involves fermentative metabolism that precedes respiration. PMID:27378203

  19. Transformation of Aspergillus parasiticus with a homologous gene (pyrG) involved in pyrimidine biosynthesis

    International Nuclear Information System (INIS)

    The lack of efficient transformation methods for aflatoxigenic Aspergillus parasiticus has been a major constraint for the study of aflatoxin biosynthesis at the genetic level. A transformation system with efficiencies of 30 to 50 stable transformants per μg of DNA was developed for A. parasiticus by using homologous pyrG gene. The pyrG gene from A. parasiticus was isolated by in situ plaque hybridization of a lambda genomic DNA library. Uridine auxotrophs of A. parasiticus ATCC 36537, a mutant blocked in aflatoxin biosynthesis, were isolated by selection on 5-fluoroorotic acid following nitrosoguanidine mutagenesis. Isolates with mutations in the pyrG gene resulting in elimination of orotidine monophosphate (OMP) decarboxylase activity were detected by assaying cell extracts for their ability to convert [14C]OMP to [14C]UMP. Transformation of A. parasiticus pyrG protoplasts with the homologous pyrG gene restored the fungal cells to prototrophy. Enzymatic analysis of cell extracts of transformant clones demonstrated that these extracts had the ability to convert [14C]OMP to [14C]UMP. Southern analysis of DNA purified from transformant clones indicated that both pUC19 vector sequences and pyrG sequences were integrated into the genome. The development of this pyrG transformation system should allow cloning of the aflatoxin-biosynthetic genes, which will be useful in studying the regulation of aflatoxin biosynthesis and may ultimately provide a means for controlling aflatoxin production in the field

  20. Biomarkers of Aspergillus spores: Strain typing and protein identification

    Czech Academy of Sciences Publication Activity Database

    Šulc, Miroslav; Pešlová, Kateřina; Žabka, Martin; Hajdúch, M.; Havlíček, Vladimír

    2009-01-01

    Roč. 280, 1-3 (2009), s. 162-168. ISSN 1387-3806 R&D Projects: GA MŠk LC07017; GA ČR GP203/05/P575 Institutional research plan: CEZ:AV0Z50200510 Keywords : aspergillus * spore * protein Subject RIV: EE - Microbiology, Virology Impact factor: 2.117, year: 2009

  1. An amendment of Aspergillus section Candidi based on chemotaxonomical evidence

    DEFF Research Database (Denmark)

    Rahbaek, L.; Frisvad, Jens Christian; Christophersen, C.

    2000-01-01

    candidus and therefore a large number of Aspergilli were screened for production of these compounds to see whether they could be regarded as chemotaxonomical indicators of section membership in the monotypic Aspergillus section Candidi. The results indicated that A. campestris and A. taichungensis should...

  2. Kinetics of alpha-amylase secretion in Aspergillus oryzae

    DEFF Research Database (Denmark)

    Henriksen, Anne Laurence Santerre; Carlsen, Morten; Bang de, H.; Nielsen, Jens Bredal

    1999-01-01

    Pulse and pulse-chase experiments have been performed to study L-[S-35] methionine incorporation and protein secretion kinetics in Aspergillus oryzae. Pulse experiments confirmed the mechanism of methionine uptake reported previously for Penicillium chrysogenum (Benko et al., 1967). Pulse...

  3. Genetic relationships among strains of the Aspergillus niger aggregate

    DEFF Research Database (Denmark)

    Ferracin, L.M.; Frisvad, Jens Christian; Taniwaki, M.H.; Iamanaka, B.T.; Sartori, D.; Schaoavaloff, M.E.; Fungaro, M.H.P.

    2009-01-01

    We analyzed the genetic relationships between 51 fungal isolates previously identified as A. niger aggregate, obtained from dried fruit samples from worldwide origin and 7 A. tubingensis obtained from Brazilian coffee beans samples. Greater fungal diversity was found in black sultanas. Aspergillus...

  4. Metabolic control analysis of Aspergillus niger L-arabinose catabolism

    DEFF Research Database (Denmark)

    de Groot, M.J.L.; Prathumpai, Wai; Visser, J.; Ruijter, G.J.G.

    2005-01-01

    A mathematical model of the L-arabinose/D-xylose catabolic pathway of Aspergillus niger was constructed based on the kinetic properties of the enzymes. For this purpose L-arabinose reductase, L-arabitol dehydrogenase and D-xylose reductase were purified using dye-affinity chromatography, and their...

  5. QUANTITATIVE PCR OF SELECTED ASPERGILLUS, PENICILLIUM AND PAECILOMYCES SPECIES

    Science.gov (United States)

    A total of 65 quantitative PCR (QPCR) assays, incorporating fluorigenic 5' nuclease (TaqMan®) chemistry and directed at the nuclear ribosomal RNA operon, internal transcribed spacer regions (ITS1 or ITS2) was developed and tested for the detection of Aspergillus, Penicillium and ...

  6. Nuclear heterogeneity in conidial populations of Aspergillus flavus

    Science.gov (United States)

    Aspergillus flavus is a major producer of aflatoxin and an opportunistic pathogen for a wide range of hosts. Understanding genotypic and phenotypic variations within strains of A. flavus is important for controlling disease and reducing aflatoxin contamination. A. flavus is multinucleate and predomi...

  7. Metabolic control analysis of xylose catabolism in Aspergillus

    DEFF Research Database (Denmark)

    Prathumpai, Wai; Gabelgaard, J.B.; Wanchanthuek, P.;

    2003-01-01

    dogma specifying that flux control often resides at the step following an intermediate present at high concentrations was, therefore, shown not to hold. The intracellular xylitol concentration was measured in batch cultivations of two different strains of Aspergillus niger and two different strains of...

  8. Study on radiation sterilization of aspergillus niger pectinase

    International Nuclear Information System (INIS)

    The result of radiation sterilization of aspergillus niger pectinase liquid by 60Co γ-rays was reported. When absorbed dose was from 1 to 25 kGy, enzyme activity didn't reduce. When absorbed dose was 15 kGy. There are no active strains in the enzyme liquid; and enzyme activity of the enzyme liquid preserved had better preserved effect

  9. Sexual Reproduction in Aflatoxin-Producing Aspergillus nomius

    Science.gov (United States)

    Aflatoxins are fungal secondary metabolites that exhibit carcinogenic, hepatotoxic and immunosuppressive properties. Aspergillus nomius is a potent producer of aflatoxins and was formerly considered to be strictly asexual in reproduction. In this research, mating-type genes MAT1-1 and MAT1-2 were ...

  10. The maize rachis affects Aspergillus flavus movement during ear development

    Science.gov (United States)

    Aspergillus flavus expressing green fluorescent protein (GFP) was used to follow infection in ears of maize hybrids resistant and susceptible to the fungus. Developing ears were needle-inoculated with GFP-transformed A. flavus 20 days after silk emergence, and GFP fluorescence in the pith was evalu...

  11. Enhanced citrate production through gene insertion in Aspergillus niger

    DEFF Research Database (Denmark)

    Jongh, Wian de; Nielsen, Jens

    2007-01-01

    The effect of inserting genes involved in the reductive branch of the tricarboxylic acid (TCA) cycle on citrate production by Aspergillus niger was evaluated. Several different genes were inserted individually and in combination, i.e. malate dehydrogenase (mdh2) from Saccharomyces cerevisiae, two...

  12. Metabolic control analysis of xylose catabolism in Aspergillus

    NARCIS (Netherlands)

    Prathumpai, W.; Gabelgaard, J.B.; Wanchanthuek, P.; Vondervoort, van de P.J.I.; Groot, de M.J.L.; McIntyre, M.; Nielsen, J.

    2003-01-01

    A kinetic model for xylose catabolism in Aspergillus is proposed. From a thermodynamic analysis it was found that the intermediate xylitol will accumulate during xylose catabolism. Use of the kinetic model allowed metabolic control analysis (MCA) of the xylose catabolic pathway to be carried out, an

  13. Production of Aspergillus niger beta-mannosidase in Pichia pastoris

    Czech Academy of Sciences Publication Activity Database

    Fliedrová, Barbora; Gerstorferová, Daniela; Křen, Vladimír; Weignerová, Lenka

    2012-01-01

    Roč. 85, č. 2 (2012), s. 159-164. ISSN 1046-5928 R&D Projects: GA ČR GAP207/10/0321; GA ČR GD305/09/H008; GA MŠk(CZ) 7E11011 Keywords : Beta-mannosidase * Aspergillus niger * Cloning Subject RIV: CE - Biochemistry Impact factor: 1.429, year: 2012

  14. Novofumigatonin, a New Orthoester Meroterpenoid from Aspergillus novofumigatus

    DEFF Research Database (Denmark)

    Rank, Christian; Phipps, Richard Kerry; Harris, Pernille; Fristrup, Peter; Larsen, Thomas Ostenfeld; Gotfredsen, Charlotte Held

    2008-01-01

    Novofumigatonin (1), a new metabolite, has been isolated from Aspergillus novofumigatus. The structure and relative stereochemistry were determined from HR ESI MS, one- and two-dimensional NMR, and single-crystal X-ray analysis. The absolute configuration was assigned using vibrational circular...

  15. epi-Aszonalenins A, B, and C from Aspergillus novofumigatus

    DEFF Research Database (Denmark)

    Rank, Christian; Phipps, Richard Kerry; Harris, Pernille;

    2006-01-01

    Three new benzodiazepines have been isolated from an unusual chemotype of Aspergillus novofumigatus: epi-aszonalenins A, B, and C. The structures were elucidated by use of one- and two-dimensional NMR spectroscopic techniques and HR ESI MS. The relative configuration was established on the basis ...

  16. Cryptic Sexuality Influences Aflatoxigenicity in Aspergillus parasiticus and A. flavus

    Science.gov (United States)

    Ascomycetous fungi of the genus Aspergillus comprise a wide variety of species of biotechnological importance as well as pathogens and toxin producers. Recent studies report A. fumigatus to be heterothallic and possibly undergoing sexual reproduction. We therefore investigated whether compatible mat...

  17. Cancer genomics

    DEFF Research Database (Denmark)

    Norrild, Bodil; Guldberg, Per; Ralfkiær, Elisabeth Methner

    2007-01-01

    Almost all cells in the human body contain a complete copy of the genome with an estimated number of 25,000 genes. The sequences of these genes make up about three percent of the genome and comprise the inherited set of genetic information. The genome also contains information that determines whe...

  18. Tet-on, or Tet-off, that is the question: Advanced conditional gene expression in Aspergillus.

    Science.gov (United States)

    Wanka, Franziska; Cairns, Timothy; Boecker, Simon; Berens, Christian; Happel, Anna; Zheng, Xiaomei; Sun, Jibin; Krappmann, Sven; Meyer, Vera

    2016-04-01

    In Aspergillus, controlled gene expression is often achieved using the reverse tetracycline-controlled transactivator (rtTA) dependent Tet-on system, whereby transcription is activated in a titratable manner by addition of the tetracycline derivative doxycycline. The complementary Tet-off system utilises the tetracycline-controlled transactivator (tTA) component to quantitatively reduce gene expression. In this study, we utilised a synthetic biological approach to engineer highly optimised Tet-off conditional expression systems in Aspergillus niger and Aspergillus fumigatus. Steps for delivery of these tools include utilising codon optimised cassette components, testing several promoters for improved genetic stability and validating two modified luciferase reporters for highly accurate measurements of gene expression. The Tet-off cassettes developed in this study enable facile and quantitative functional analysis, as validated by Tet-off analysis of genes involved in chitin synthesis and cell wall polarity in A. niger, and para-aminobenzoic acid synthesis in A. fumigatus. We also used a racA(G18V) dominant allele to demonstrate that Tet-off in A. niger enables gene over-expression and downregulation in a single isolate. Additionally, we used the improved luciferase reporters to show that the Tet-off cassette in A. niger enables quantification of gene oscillations. In order to demonstrate that synthetic biological approaches developed here are broadly applicable to engineering transcriptional circuits in filamentous fungi, we used our strategy for improving cassette stability by promoter replacement in the A. niger Tet-on system, which resulted in a modified Tet-on cassette with higher stability in recipient genomes. PMID:26555930

  19. AMINO ACID SUPPLEMENTATION REVEALS DIFFERENTIAL REGULATION OF AFLATOXIN BIOSYNTHESIS IN ASPERGILLUS FLAVUS NRRL 3357 AND ASPERGILLUS PARASITICUS SRRC 143

    Science.gov (United States)

    Aflatoxins are toxic and carcinogenic secondary metabolites produced by the fungi Aspergillus flavus and A. parasiticus. In order to better understand the molecular mechanisms that regulate aflatoxin production, the biosynthesis of the toxin in A. flavus and A. parasiticus grown in yeast extract su...

  20. Metabolomics Analysis Reveals Specific Novel Tetrapeptide and Potential Anti-Inflammatory Metabolites in Pathogenic Aspergillus species

    Directory of Open Access Journals (Sweden)

    Kim-Chung Lee

    2015-06-01

    Full Text Available Infections related to Aspergillus species have emerged to become an important focus in infectious diseases, as a result of the increasing use of immunosuppressive agents and high fatality associated with invasive aspergillosis. However, laboratory diagnosis of Aspergillus infections remains difficult. In this study, by comparing the metabolomic profiles of the culture supernatants of 30 strains of six pathogenic Aspergillus species (A. fumigatus, A. flavus, A. niger, A. terreus, A. nomius and A. tamarii and 31 strains of 10 non-Aspergillus fungi, eight compounds present in all strains of the six Aspergillus species but not in any strain of the non-Aspergillus fungi were observed. One of the eight compounds, Leu–Glu–Leu–Glu, is a novel tetrapeptide and represents the first linear tetrapeptide observed in Aspergillus species, which we propose to be named aspergitide. Two other closely related Aspergillus-specific compounds, hydroxy-(sulfooxybenzoic acid and (sulfooxybenzoic acid, may possess anti-inflammatory properties, as 2-(sulfooxybenzoic acid possesses a structure similar to those of aspirin [2-(acetoxybenzoic acid] and salicylic acid (2-hydroxybenzoic acid. Further studies to examine the potentials of these Aspergillus-specific compounds for laboratory diagnosis of aspergillosis are warranted and further experiments will reveal whether Leu–Glu–Leu–Glu, hydroxy-(sulfooxybenzoic acid and (sulfooxybenzoic acid are virulent factors of the pathogenic Aspergillus species.

  1. A CIS-Dominant Mutation in ASPERGILLUS NIDULANS Affecting the Expression of the amdS Gene in the Presence of Mutations in the Unlinked Gene, amdA

    OpenAIRE

    Hynes, Michael J.

    1982-01-01

    A mutant producing very high levels of the acetamidase enzyme encoded by the amdS gene has been isolated in a strain containing the amdA7 mutation, which itself causes high levels of this enzyme. Genetic analysis has shown that this mutation, designated amdI66, is adjacent to the amdS gene and is cis-dominant in its effect. The amdI66 mutation has little effect on amdS expression when present in strains not containing the amdA7 mutation. Two other amdA mutations investigated also interact wit...

  2. Characterization of a polyketide synthase in Aspergillus niger whose product is a precursor for both dihydroxynaphthalene (DHN) melanin and naphtho-γ-pyrone.

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, Yi Ming; Meyer, Kristen M; Praseuth, Michael; Baker, Scott E; Bruno, Kenneth S; Wang, Clay C

    2010-12-06

    The genome sequencing of the fungus Aspergillus niger, an industrial workhorse, uncovered a large cache of genes encoding enzymes thought to be involved in the production of secondary metabolites yet to be identified. Identification and structural characterization of many of these predicted secondary metabolites are hampered by their low concentration relative to the known A. niger metabolites such as the naphtho-γ-pyrone family of polyketides. We deleted a nonreducing PKS gene in A. niger strain ATCC 11414, a daughter strain of A. niger ATCC strain 1015 whose genome was sequenced by the DOE Joint Genome Institute. This PKS encoding gene is a predicted ortholog of alb1 from Aspergillus fumigatus which is responsible for production of YWA1, a precursor of fungal DHN melanin. Our results show that the A. niger alb1 PKS is responsible for the production of the polyketide precursor for DHN melanin biosynthesis. Deletion of alb1 elimnates the production of major metabolites, naphtho-γ-pyrones. The generation of an A. niger strain devoid of naphtho-γ-pyrones will greatly facilitate the elucidation of cryptic biosynthetic pathways in this organism.

  3. .i.Aspergillus baeticus./i. sp. nov. and .i.Aspergillus thesauricus./i. sp. nov., two species in section .i.Usti./i. from Spanish caves

    Czech Academy of Sciences Publication Activity Database

    Nováková, Alena; Hubka, Vít; Saiz-Jimenez, C.; Kolařík, Miroslav

    2012-01-01

    Roč. 62, November (2012), s. 2778-2785. ISSN 1466-5026 Grant ostatní: GAUK(CZ) 607812 Institutional research plan: CEZ:AV0Z60660521; CEZ:AV0Z50200510 Keywords : Aspergillus baeticus sp. nov. * Aspergillus thesauricus sp.nov. * Spanish caves Subject RIV: EH - Ecology, Behaviour Impact factor: 2.112, year: 2012

  4. Transcriptional regulation of chemical diversity in Aspergillus fumigatus by LaeA.

    Directory of Open Access Journals (Sweden)

    Robyn M Perrin

    2007-04-01

    Full Text Available Secondary metabolites, including toxins and melanins, have been implicated as virulence attributes in invasive aspergillosis. Although not definitively proved, this supposition is supported by the decreased virulence of an Aspergillus fumigatus strain, DeltalaeA, that is crippled in the production of numerous secondary metabolites. However, loss of a single LaeA-regulated toxin, gliotoxin, did not recapitulate the hypovirulent DeltalaeA pathotype, thus implicating other toxins whose production is governed by LaeA. Toward this end, a whole-genome comparison of the transcriptional profile of wild-type, DeltalaeA, and complemented control strains showed that genes in 13 of 22 secondary metabolite gene clusters, including several A. fumigatus-specific mycotoxin clusters, were expressed at significantly lower levels in the DeltalaeA mutant. LaeA influences the expression of at least 9.5% of the genome (943 of 9,626 genes in A. fumigatus but positively controls expression of 20% to 40% of major classes of secondary metabolite biosynthesis genes such as nonribosomal peptide synthetases (NRPSs, polyketide synthases, and P450 monooxygenases. Tight regulation of NRPS-encoding genes was highlighted by quantitative real-time reverse-transcription PCR analysis. In addition, expression of a putative siderophore biosynthesis NRPS (NRPS2/sidE was greatly reduced in the DeltalaeA mutant in comparison to controls under inducing iron-deficient conditions. Comparative genomic analysis showed that A. fumigatus secondary metabolite gene clusters constitute evolutionarily diverse regions that may be important for niche adaptation and virulence attributes. Our findings suggest that LaeA is a novel target for comprehensive modification of chemical diversity and pathogenicity.

  5. Concomitant Aspergillus Species Infection and Squamous Cell Carcinoma Diagnosed on Pap Smear.

    Science.gov (United States)

    Gupta, Prajwala; Goyal, Snigdha; Kaushal, Manju

    2016-01-01

    Concomitant infection with Aspergillus species and cervical squamous cell carcinoma in the female genital tract is a rare occurrence and attributed to the opportunistic nature of infection in the immunocompromised state due to the underlying malignancy. The contamination of smears with Aspergillus species should be excluded. The diagnosis of Aspergillus species infection along with squamous cell carcinoma was established on cervicovaginal pap smears in a 62-year-old female presented to gynecological clinic with complaints of stress urinary incontinence. Speculum examination revealed first-degree cervical descent. Smears showed features of squamous cell carcinoma along with fungal spores and fruiting body with hyphae of Aspergillus species. The presence of fruiting bodies and hyphae of Aspergillus species with coexisting squamous cell carcinoma is rare in routine pap smears. True infection needs to be distinguished from contamination by Aspergillus species. Early diagnosis can be established on routine cervicovaginal Pap smear examination. PMID:24272933

  6. Segregação mitótica induzida pelo edulcorante L-Aspartil-L-Fenilalanina-Metil-Ester (aspartame) em células diplóides de Aspergillus nidulans - DOI: 10.4025/actascibiolsci.v25i1.2121 Mitotic segregation induced by edulcorant l-aspartyl-l-phenylalanine-metyl-ester (aspartame) in diploid cells of Aspergillus nidulans - DOI: 10.4025/actascibiolsci.v25i1.2121

    OpenAIRE

    Marialba Avezum Alves Castro Prado; Munif Gebara; Carmem Boto Querol; Josil Santos Gebara

    2003-01-01

    O presente trabalho demonstra o efeito recombinagênico do edulcorante artificial L-Aspartil-L-Fenilalanina-Metil-Ester (aspartame), amplamente utilizado em dietas hipocalóricas e de baixo consumo de glicose. Este efeito pode refletir respostas celulares a danos genéticos induzidos pelo edulcorante artificial, no período G2 do ciclo celular e demonstra sua capacidade de induzir homozigose de genes recessivos previamente presentes em heterozigoseThis study aims to verify the recombinogenic effe...

  7. Segregação mitótica induzida pelo edulcorante L-Aspartil-L-Fenilalanina-Metil-Ester (aspartame em células diplóides de Aspergillus nidulans - DOI: 10.4025/actascibiolsci.v25i1.2121 Mitotic segregation induced by edulcorant l-aspartyl-l-phenylalanine-metyl-ester (aspartame in diploid cells of Aspergillus nidulans - DOI: 10.4025/actascibiolsci.v25i1.2121

    Directory of Open Access Journals (Sweden)

    Marialba Avezum Alves Castro Prado

    2003-04-01

    Full Text Available O presente trabalho demonstra o efeito recombinagênico do edulcorante artificial L-Aspartil-L-Fenilalanina-Metil-Ester (aspartame, amplamente utilizado em dietas hipocalóricas e de baixo consumo de glicose. Este efeito pode refletir respostas celulares a danos genéticos induzidos pelo edulcorante artificial, no período G2 do ciclo celular e demonstra sua capacidade de induzir homozigose de genes recessivos previamente presentes em heterozigoseThis study aims to verify the recombinogenic effect of artificial edulcorant l-aspartil-l-phenylalanine-metyl-ester (aspartame, widely used in hypocaloric and low-glucose diets. Such effect may reflect cell response to genetic damage, induced by artificial edulcorant in the cell cycle G2 period and shows its capacity to induce homozygosis of recessive genes, previously present in heterozygosis

  8. Peanut gene expression profiling in developing seeds at different reproduction stages during Aspergillus parasiticus infection

    Directory of Open Access Journals (Sweden)

    Liang Xuanqiang

    2008-02-01

    Full Text Available Abstract Background Peanut (Arachis hypogaea L. is an important crop economically and nutritionally, and is one of the most susceptible host crops to colonization of Aspergillus parasiticus and subsequent aflatoxin contamination. Knowledge from molecular genetic studies could help to devise strategies in alleviating this problem; however, few peanut DNA sequences are available in the public database. In order to understand the molecular basis of host resistance to aflatoxin contamination, a large-scale project was conducted to generate expressed sequence tags (ESTs from developing seeds to identify resistance-related genes involved in defense response against Aspergillus infection and subsequent aflatoxin contamination. Results We constructed six different cDNA libraries derived from developing peanut seeds at three reproduction stages (R5, R6 and R7 from a resistant and a susceptible cultivated peanut genotypes, 'Tifrunner' (susceptible to Aspergillus infection with higher aflatoxin contamination and resistant to TSWV and 'GT-C20' (resistant to Aspergillus with reduced aflatoxin contamination and susceptible to TSWV. The developing peanut seed tissues were challenged by A. parasiticus and drought stress in the field. A total of 24,192 randomly selected cDNA clones from six libraries were sequenced. After removing vector sequences and quality trimming, 21,777 high-quality EST sequences were generated. Sequence clustering and assembling resulted in 8,689 unique EST sequences with 1,741 tentative consensus EST sequences (TCs and 6,948 singleton ESTs. Functional classification was performed according to MIPS functional catalogue criteria. The unique EST sequences were divided into twenty-two categories. A similarity search against the non-redundant protein database available from NCBI indicated that 84.78% of total ESTs showed significant similarity to known proteins, of which 165 genes had been previously reported in peanuts. There were

  9. Enhanced aflatoxin production by aspergillus parasiticus and aspergillus flavus after low dose gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Hitoshi (Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment)

    1992-09-01

    Spores of Aspergillus parasiticus IFO 30179 and A. flavus var. columnaris S46 were irradiated at 0.05, 0.2 and 0.4 kGy in the synthetic low salts (SL) broth, and the effect on aflatoxin production was examined after 10 days incubation at 30 or 25degC. In these two strains, irradiation of spores at 0.05 kGy resulted in higher B1 or G1 production than the non-irradiated controles. However, spores of the both strains irradiated at 0.2 or 0.4 kGy produced less aflatoxins than non-irradiated controles. In the SL broth, apparent stimulation by low dose irradiation was slight, and these enhanced effects were not observed after reinfection to fresh SL broth. In the case of food samples, the levels of aflatoxin B[sub 1] and G[sub 1] with A. parasiticus were increased from 15 to 90% by incubation of irradiated spores at 1 kGy in autoclaved polished rice, black pepper, white pepper and red pepper. These enhancement would be induced by change of composition in each substrates. Mutations of fungi induced by irradiation is not effective for enhancement of aflatoxin production. (author).

  10. Expression of an alpha-galactosidase from Saccharomyces cerevisiae in Aspergillus awamori and Aspergillus oryzae.

    Science.gov (United States)

    Murphy, R A; Power, R F G

    2002-02-01

    A gene encoding alpha-galactosidase activity was isolated by polymerase chain reaction (PCR) from Saccharomyces cerevisiae NCYC686 and separately placed under the control of transcriptional elements regulating alpha-amylase expression in Aspergillus oryzae and glucoamylase expression in A. awamori. Following transformation of both A. oryzae and A. awamori with their respective expression vectors, induction of heterologous alpha-galactosidase from positively selected clones was effected through the addition of soluble starch (10% wt/vol) to the growth medium. Upon induction in A. oryzae, a transcriptional instability resulted in degradation of mRNA encoding heterologous alpha-galactosidase, thus preventing expression of the active enzyme. The use of a gene fusion strategy in A. awamori overcame this instability and resulted in stable expression of S. cerevisiae alpha-galactosidase. Subsequent to initial (shake flask) experiments, a series of scale-up and optimisation studies led to heterologous expression of the recombinant enzyme in batch fermentation at 51 U mg(-1) total extracellular protein. This was higher than previously published works, which reported extracellular levels of heterologous alpha-galactosidase up to 38 U mg(-1) total protein. Analysis of crude extracts of the fermentation medium revealed significant differences between the activity parameters reported previously in the literature for this enzyme and those observed here. The recombinant enzyme exhibited thermostability properties not previously reported for S. cerevisiae alpha-galactosidase, a trait which would make it suitable for use in processes requiring high temperatures. PMID:12074058

  11. Enhanced aflatoxin production by aspergillus parasiticus and aspergillus flavus after low dose gamma irradiation

    International Nuclear Information System (INIS)

    Spores of Aspergillus parasiticus IFO 30179 and A. flavus var. columnaris S46 were irradiated at 0.05, 0.2 and 0.4 kGy in the synthetic low salts (SL) broth, and the effect on aflatoxin production was examined after 10 days incubation at 30 or 25degC. In these two strains, irradiation of spores at 0.05 kGy resulted in higher B1 or G1 production than the non-irradiated controles. However, spores of the both strains irradiated at 0.2 or 0.4 kGy produced less aflatoxins than non-irradiated controles. In the SL broth, apparent stimulation by low dose irradiation was slight, and these enhanced effects were not observed after reinfection to fresh SL broth. In the case of food samples, the levels of aflatoxin B1 and G1 with A. parasiticus were increased from 15 to 90% by incubation of irradiated spores at 1 kGy in autoclaved polished rice, black pepper, white pepper and red pepper. These enhancement would be induced by change of composition in each substrates. Mutations of fungi induced by irradiation is not effective for enhancement of aflatoxin production. (author)

  12. Evaluation of antifungal activity of essential oils against potentially mycotoxigenic Aspergillus flavus and Aspergillus parasiticus

    Directory of Open Access Journals (Sweden)

    Fernanda C. da Silva

    2012-10-01

    Full Text Available The antifungal activity of essential oils of fennel (Foeniculum vulgare Mill., Apiaceae, ginger (Zingiber officinale Roscoe, Zingiberaceae, mint (Mentha piperita L., Lamiaceae and thyme (Thymus vulgaris L., Lamiaceae was evaluated against mycotoxin producers Aspergillus flavus and A. parasiticus. High Resolution Gas Chromatography was applied to analyze chemical constituents of essential oils. The effect of different concentrations of essential oils was determined by solid medium diffusion assay. Mycelial growth and sporulation were determined for each essential oil at the concentrations established by solid medium diffusion assay. At the fifth, seventh and ninth days the mycelial diameter (Ø mm and spore production were also determined. FUN-1 staining was performed to assess cell viability after broth macrodilution assay. Trans-anethole, zingiberene, menthol and thymol are the major component of essential oils of fennel, ginger, mint and thyme, respectively. The effective concentrations for fennel, ginger, mint and thyme were 50, 80, 50 and 50% (oil/DMSO; v/v, respectively. The four essential oils analysed in this study showed antifungal effect. Additionally, FUN-1 staining showed to be a suitable method to evaluate cell viability of potential mycotoxigenic fungi A. flavus and A. parasiticus after treatment with essential oils.

  13. Research on Real-Time Quantitative PCR Technology of Common Aspergillus Species%常见曲霉菌的实时定量PCR诊断技术的研究

    Institute of Scientific and Technical Information of China (English)

    武学成; 龚文胜

    2012-01-01

    Objective The detected method of real-time quantitative PCR technology on common Aspergillus Species was developed. Methods The employing universal, fungus-specific primers and DNA probes, directed to the conservative internal transcribed spacer 2(ITS2) region of ribosomal DNA from A, terreus, A flavus, A. Fumigatus, A. Terreus, A. Nidulans and A niger were designed. Five kinds of common Aspergillus Species were detected by the quantitative real-time PCR and common PCR technology. Results DNA from each Aspergillus species for which DNA probes were designed produced am-plicons of approximately 350bp in size. Melting temperature of A, terreus, A. Flavus, A. Fumigatus,A terreus, A. Nidulajis and A. Niger was respectively 57℃ ± 0. 12℃ , 59℃ ± 0. 13℃ , 63℃ ± 0. 17℃ , 66°C ± 0. 15℃ , 66℃ ± 0. 14℃ and 68℃± 0. 12°C by melting peak analysis for five different Aspergillus spp. The minimum reaction concentration of DNA response template of A terreus, A flavus, A fumigatus, A nidulans and A niger was respectively 82. 4, 621. 3, 51. 2, 520. 8 and 19. 5 fg/μl by sensitivity analysis of common Aspergillus species. Conclusion The developed technology of real-time quantitative PCR is simple, rapid, and sensitive for the identification of medically important common Aspergillus species, which was a new option in invasive aspergillosis diagnosis.%目的 建立常见曲霉菌的实时定量PCR诊断技术.方法 针对黄曲霉菌、烟曲霉菌、构巢曲霉菌、黑曲霉菌和土曲霉菌内转录间隔区2(internal transcribed spacer 2,ITS2)保守基因设计引物和探针,通过普通PCR扩增其ITS2基因片段,作为实时定量PCR反应模板,通过实时定量扩增和分析其解链曲线来鉴定常见曲霉菌,同时分析该方法灵敏度.结果 真菌通用引物扩增五种常见曲霉菌ITS2基因DNA片段,大小为350 bp左右.实时定量PCR分析和探针解链曲线分析结果显示土曲霉解链温度(melting temperature

  14. Aspergillus as a multi-purpose cell factory: current status and perspectives

    OpenAIRE

    2010-01-01

    Abstract Aspergilli have a long history in biotechnology as expression platforms for the production of food ingredients, pharmaceuticals and enzymes. The achievements made during the last years, however, have the potential to revolutionize Aspergillus biotechnology and to assure Aspergillus a dominant place among microbial cell factories. This mini-review will highlight most recent breakthroughs in fundamental and applied Aspergillus research with a focus on new molecular tools, te...

  15. In Vitro Interactions between Target of Rapamycin Kinase Inhibitor and Antifungal Agents against Aspergillus Species.

    Science.gov (United States)

    Gao, Lujuan; Ding, Xiaozhen; Liu, Zhun; Wu, Qingzhi; Zeng, Tongxiang; Sun, Yi

    2016-06-01

    In vitro interactions of INK128, a target of rapamycin (TOR) kinase inhibitor, and antifungals, including itraconazole, voriconazole, posaconazole, amphotericin B, and caspofungin, against Aspergillus spp. were assessed with the broth microdilution checkerboard technique. Our results suggested synergistic effects between INK128 and all azoles tested, against multiple Aspergillus fumigatus and Aspergillus flavus isolates. However, no synergistic effects were observed when INK128 was combined with amphotericin B or caspofungin. No antagonism was observed for any combination. PMID:26976874

  16. Immunosuppressive Compounds Exhibit Particular Effects on Functional Properties of Human Anti-Aspergillus TH1 Cells

    OpenAIRE

    Tramsen, Lars; Schmidt, Stanislaw; Roeger, Frauke; Schubert, Ralf; Salzmann-Manrique, Emilia; Latgé, Jean-Paul; Klingebiel, Thomas; Lehrnbecher, Thomas

    2014-01-01

    Allogeneic hematopoietic stem cell transplant (HSCT) recipients are at high risk for invasive aspergillosis. Whereas adoptive immunotherapy transferring donor-derived anti-Aspergillus TH1 cells has been shown to be beneficial for HSCT recipients suffering from invasive aspergillosis, little is known about the impact of commonly used immunosuppressants on the functional properties of anti-Aspergillus TH1 cells. Anti-Aspergillus TH1 cells were coincubated with different concentrations of methyl...

  17. Invasive aspergillosis in the aortic arch with infectious Aspergillus lesions in pulmonary bullae

    Directory of Open Access Journals (Sweden)

    Isao Watanabe

    2015-03-01

    Full Text Available A patient with pulmonary bullae died of massive hemoptysis. At autopsy a hole was observed in the aortic wall. A microscopic examination indicated small Aspergillus lesions in pulmonary bullae and extensive necrotic lesions with Aspergillus hyphae in the media of the thoracic aorta. These findings led to a diagnosis of invasive aspergillosis in the aortic arch. This is a rare case in which Aspergillus invaded the aorta in a patient without hematologic neoplasms or neutropenia.

  18. Production of biologically active recombinant human lactoferrin in Aspergillus oryzae.

    Science.gov (United States)

    Ward, P P; Lo, J Y; Duke, M; May, G S; Headon, D R; Conneely, O M

    1992-07-01

    We report the production of recombinant human lactoferrin in Aspergillus oryzae. Expression of human lactoferrin (hLF), a 78 kD glycoprotein, was achieved by placing the cDNA under the control of the A. oryzae alpha-amylase promoter and the 3' flanking region of the A. niger glucoamylase gene. Using this system, hLF is expressed and secreted into the growth medium at levels up to 25 mg/l. The recombinant lactoferrin is indistinguishable from human milk lactoferrin with respect to its size, immunoreactivity, and iron-binding capacity. The recombinant protein appears to be appropriately N-linked glycosylated and correctly processed at the N-terminus by the A. oryzae secretory apparatus. Lactoferrin is the largest heterologous protein and the first mammalian glycoprotein expressed in the Aspergillus system to date. Hence, this expression system appears suitable for the large-scale production and secretion of biologically active mammalian glycoproteins. PMID:1368268

  19. Decolorization of Direct Black 22 by Aspergillus ficuum

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The decolorization of Direct Black 22 by Aspergillus ficuum has been studied. It was found that Aspergillus ficuum could effectively decolorize Direct Black 22 especially when grown as pelleted mycelia. Results showed that the media containing Direct Black 22 at 50 mg/L could be decolorized by 98.05% of the initial color in 24 h. The optimum pH and temperature of decolorization are 4.0 and 33 ℃ respectively. Aeration was quite beneficial to decolorization. Medium composition and the concentration of Direct Black 22 could affect the rate of decolorization. The dye degraded products assayed by UV-visible spectrophotometer and macroscopic observation showed that the decolorization of Direct Black 22 by mycelial pellets includes two important processes: bioadsorption and biodegradation.The degradation experiment agree with the Michaelis-Menten kinetics equation

  20. Biosorption of Cadmium by Fungal Biomass of Aspergillus niger

    Institute of Scientific and Technical Information of China (English)

    QI YANG; JIAN-LONG WANG; ZHI XING

    2005-01-01

    Objective To investigate the removal of cadmium from aqueous solution by waste fungal biomass of Aspergillus niger, originated from citric acid fermentation industry. Methods Batch adsorption test was used to study the biosorption equilibrium and isotherm. The Cd2+ concentration was measured with atomic adsorption spectrophotometer (AAS) HITACHI 180-80. Results The biosorption achieved equilibrium within 30 min. The adsorption isotherm could be described by Freundlich adsorption model, and the constants KF and 1/n were determined to be 2.07 and 0.18, respectively, and the correlation efficiency was 0.97. The optimal pH for Cd adsorption was 6.0. The cadmium-laden biomass could be effectively regenerated using 0.1 N HCl. Conclusion The waste biomass of Aspergillus niger, a by-product of fermentation industry, is a potential biosorbent for the removal of cadmium from aqueous solution.

  1. Different species of Aspergillus involved in ungual pathologies

    Directory of Open Access Journals (Sweden)

    M. Zotti

    2011-01-01

    Full Text Available In recent years non dermatophyte fungi (NDF are often described as responsible for onychomycosis. The problem related to these fungi concern their identification and treatment. Nowadays a number of Aspergillus were observed in this kind of pathologies but the identification at level of species is frequently omitted. In this work we analysed 26 cases of onychomycosis caused by Aspergillus, belonging to 8 different species. The identification were based on micro- and macro-morphological characteristics; physiological characters; and molecular analysis (B-tubulin gene. 3 species are very interesting: A. perii, a species recently described; A.nominus, never described before in onychomycosis, and A.melleus, likely a new opportunistic fungus involved in medical mycology. Though the identification of these fungi is an additional workload for the laboratory of medical mycology, there is the need to increase the number of identified NDF in order to improve the management of onychomycosis.

  2. Biosorption of cadmium using the fungus Aspergillus niger

    Directory of Open Access Journals (Sweden)

    L.M. Barros Júnior

    2003-09-01

    Full Text Available Sorption experiments using the Aspergillus niger fungus for cadmium removal were carried out to study the factors influencing and optimizing the biosorption of this metal. The effects of pH, time, biomass concentration, and initial concentration of the heavy metal on the rate of metallic biosorption were examined. An experimental design was also used to determine the values of the under study variables that provided the greatest biosorption efficiency. A technique for biomass recovery was also developed with the objective of determining the capacity of the regenerated biomass to biosorb the metals in solution. This research proved that with a pH of 4.75, a biomass concentration of 0.7 g/L, and a heavy metal concentration varying between 5 and 10 mg/L a biosorption process of biosorption with Aspergillus niger could be successfully used for heavy metal removal from oil field water in the oil industry.

  3. Primary cutaneous aspergillosis due to Aspergillus flavus: a case report

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qiang-qiang; LI Li; ZHU Min; ZHANG Chao-ying; WANG Jia-jun

    2005-01-01

    @@ Infections caused by opportunistic organisms which have been known as etiologic agents of disease become more and more frequent.Aspergillus spp. is one of the agents. Fungi of aspergillus genus are widely distributed in nature, particularly in the soil and in the decomposed vegetation. They are frequent opportunist pathogens in immunocompromised patients. The most frequent causative organisms that cause cutaneous aspergillosis are A.fumigatus and A.flavus.1-3 In this report, we present a case of primary cutaneous aspergillosis manifested by ulceration of the shank due to A. flavus. The patient had no deficiency of immunological status and severe disease associated with fungal infection. Excellent response was shown to anti-fungal therapy.

  4. Fumonisin and Ochratoxin Production in Industrial Aspergillus niger Strains

    DEFF Research Database (Denmark)

    Frisvad, Jens Christian; Larsen, Thomas Ostenfeld; Thrane, Ulf;

    2011-01-01

    Aspergillus niger is perhaps the most important fungus used in biotechnology, and is also one of the most commonly encountered fungi contaminating foods and feedstuffs, and occurring in soil and indoor environments. Many of its industrial applications have been given GRAS status (generally regarded...... as safe). However, A. niger has the potential to produce two groups of potentially carcinogenic mycotoxins: fumonisins and ochratoxins. In this study all available industrial and many non-industrial strains of A. niger (180 strains) as well as 228 strains from 17 related black Aspergillus species...... were examined for mycotoxin production. None of the related 17 species of black Aspergilli produced fumonisins. Fumonisins (B(2), B(4), and B(6)) were detected in 81% of A. niger, and ochratoxin A in 17%, while 10% of the strains produced both mycotoxins. Among the industrial strains the same ratios...

  5. Significance and occurrence of fumonisins from Aspergillus niger

    DEFF Research Database (Denmark)

    Mogensen, Jesper Mølgaard

    Fumonisins is a well-studied group of mycotoxins, mainly produced in maize by Fusarium species. However with the recent discovery of a fumonisin production by Aspergillus niger, other food commodities are at risk, since A. niger is a ubiquitous contaminant of many food and feed products. The...... objective of this thesis was to determine the significance and occurrence of fumonisins from Aspergillus niger in food, the frequency of fumonisin production in A. niger isolates, as well as studies of the effect of physiological factors affecting fumonisin production. Major findings in this context have....... Sixty-six A. niger strains were isolated and screened for a fumonisin production, and 77 % produced fumonisin on agar media. Worst-case scenarios were made by inoculation of A. niger on grapes and solidified the thought that a potential fumonisin production/contamination in grapes and derived products...

  6. Fumonisins in Aspergillus niger: Industrial and food aspects

    DEFF Research Database (Denmark)

    Frisvad, Jens Christian; Nielsen, Kristian Fog; Mogensen, Jesper;

    Introduction: Fumonisins are toxic seconday metabolites from Fusarium verticillioides and other Fusaria, from Tolypocladium and Aspergillus niger 1,2. Being a generalist Aspergillus niger is the workhorse in a very large number of industrial applications, and is also a common contaminant in foods...... ever used in biotechnology could produce fuminisins B2, B4 & B6. The strains could be subdivided into two clades (representing A. niger and the “phylospecies” A. awamori), and there were fumonisin producers in both clades. Ochratoxin A was also produced by strains in both clades, but only...... of approximately 6% of the strains. None of the other species in the black Aspergilli produced fumonisins. One strain (NRRL 337), called the “food fungus”, because it is used for single cell protein based on cheap growth substrates, produced both fumonisins and ochratoxin A. Industrial citric acid producers...

  7. Metabolic control analysis of xylose catabolism in Aspergillus

    DEFF Research Database (Denmark)

    Prathumpai, Wai; Gabelgaard, J.B.; Wanchanthuek, P.; van de Vondervoort, P.J.I.; de Groot, M.J.L.; Mcintyre, Mhairi; Nielsen, Jens

    2003-01-01

    A kinetic model for xylose catabolism in Aspergillus is proposed. From a thermodynamic analysis it was found that the intermediate xylitol will accumulate during xylose catabolism. Use of the kinetic model allowed metabolic control analysis (MCA) of the xylose catabolic pathway to be carried out......, and flux control was shown to be dependent on the metabolite levels. Due to thermodynamic constraints, flux control may reside at the first step in the pathway, i.e., at the xylose reductase, even when the intracellular xylitol concentration is high. On the basis of the kinetic analysis, the general...... dogma specifying that flux control often resides at the step following an intermediate present at high concentrations was, therefore, shown not to hold. The intracellular xylitol concentration was measured in batch cultivations of two different strains of Aspergillus niger and two different strains of...

  8. Biotransformation of steviol derivatives by Aspergillus niger and Fusarium moniliforme

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Bras H. de; Leal, Paulo C. [Parana Univ., Curitiba, PR (Brazil). Dept. de Quimica]. E-mail: bho@ufpr.br; Souza Filho, Jose Dias [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Quimica

    2005-04-01

    Steviol derivatives have been submitted to biotransformations by fungi. Methyl ent-11{beta},13-dihydroxy-15,16-epoxikauran-19-oate was hydroxylated at C-11 by Aspergillus niger, whereas ent-16{beta}-hydroxybeyeran-19-oic acid was hydroxylated at C-6 and C-7 by Fusarium moniliforme. The hydroxylation at non-activated positions at the carbon skeleton is discussed in connection with the properties of important polyhydroxylated diterpenoids described in the literature. (author)

  9. Biosorption of cadmium using the fungus Aspergillus niger

    OpenAIRE

    Barros Júnior L.M.; Macedo G.R.; Duarte M.M.L.; Silva E.P.; Lobato A.K.C.L.

    2003-01-01

    Sorption experiments using the Aspergillus niger fungus for cadmium removal were carried out to study the factors influencing and optimizing the biosorption of this metal. The effects of pH, time, biomass concentration, and initial concentration of the heavy metal on the rate of metallic biosorption were examined. An experimental design was also used to determine the values of the under study variables that provided the greatest biosorption efficiency. A technique for biomass recovery was als...

  10. Protein secretion in the filamentous fungus Aspergillus niger

    OpenAIRE

    Weenink, Xavier Oswin

    2008-01-01

    Filamentous fungi are multicellular eukaryotic organisms, which represent a separate taxonomic group organisms within the fungal kingdom, apart from the yeasts. These fungi always need a substrate to grow on, this can be living or dead material. Fungi possess the capacity to secrete high levels of enzymes. Because of this specific property, fungi are already used for centuries as miniature factories for the production of extracellular proteins. Aspergillus niger is an attractive organism beca...

  11. Four Novel Hydropyranoindeno- Derivatives from Marine Fungus Aspergillus versicolor

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    From the cultured filtrates of fungus Aspergillus versicolor,isolated from marine sponge Xestospongia exigua,four novel secondary metabolites,namely aspergillone 1,aspergillodiol 2, aspergillol 3 and 12-acetyl-aspergillol 4,have been isolated by column chromatographic separation.The structures of all the new compounds are established on the basis of extensive 2D NMR spectroscopy in conjugation with MS,UV spectral analysis.The basic structure pattern of those compounds possessed an hydroindenoisopyran nucleus.

  12. Raw starch conversion by Saccharomyces cerevisiae expressing Aspergillus tubingensis amylases

    OpenAIRE

    Viktor, Marko J; Rose, Shaunita H.; van Zyl, Willem H; Viljoen-Bloom, Marinda

    2013-01-01

    Background Starch is one of the most abundant organic polysaccharides available for the production of bio-ethanol as an alternative transport fuel. Cost-effective utilisation of starch requires consolidated bioprocessing (CBP) where a single microorganism can produce the enzymes required for hydrolysis of starch, and also convert the glucose monomers to ethanol. Results The Aspergillus tubingensis T8.4 α-amylase (amyA) and glucoamylase (glaA) genes were cloned and expressed in the laboratory ...

  13. Calcineurin Controls Growth, Morphology, and Pathogenicity in Aspergillus fumigatus

    OpenAIRE

    Steinbach, William J.; Cramer, Robert A; Perfect, B. Zachary; Asfaw, Yohannes G.; Sauer, Theodor C.; Najvar, Laura K.; Kirkpatrick, William R.; Thomas F. Patterson; Benjamin, Daniel K., Jr.; Heitman, Joseph; Perfect, John R.

    2006-01-01

    Calcineurin is implicated in a myriad of human diseases as well as homeostasis and virulence in several major human pathogenic microorganisms. The fungus Aspergillus fumigatus is a leading cause of infectious death in the rapidly expanding immunocompromised patient population. Current antifungal treatments for invasive aspergillosis are often ineffective, and novel therapeutic approaches are urgently needed. We demonstrate that a mutant of A. fumigatus lacking the calcineurin A (cnaA) catalyt...

  14. Isolation and Characterization of Aspergillus oryzae Vacuolar Protein Sorting Mutants

    OpenAIRE

    Ohneda, Mamoru; Arioka, Manabu; Kitamoto, Katsuhiko

    2005-01-01

    The vacuolar protein sorting (vps) system in the filamentous fungus Aspergillus oryzae, which has unique cell polarity and the ability to secrete large amounts of proteins, was evaluated by using mutants that missort vacuolar proteins into the medium. Vacuolar carboxypeptidase Y (CPY) fused with enhanced green fluorescent protein (EGFP) was used as a vacuolar marker. Twenty dfc (dim EGFP fluorescence in conidia) mutants with reduced intracellular EGFP fluorescence in conidia were isolated by ...

  15. Central nervous system aspergillus infection complicating renal transplantation

    International Nuclear Information System (INIS)

    A case of catastrophic intracerebral haemorrhage secondary to aspergillus infection in an immunocompromised renal transplant patient is presented. The pathological features and related images are described and the radiology of CNS aspergillus infection is reviewed. A 37-year-old woman was admitted with abdominal pain. She had recently received a cadaveric renal transplant following failure of the previous live donor kidney. Gastroscopy showed changes suspicious of cytomegalovirus (CMV) gastroduodenitis and she was treated with gancyclovir, with resolution of her symptoms. While in hospital her creatinine began to rise. The renal biopsy was suggestive of cyclosporin toxicity and the cyclosporin level was raised 537 mg/mL (normal 160-360 mg/mL). Several days later, she developed slurred speech and weakness in her right arm. Non-contrast CT showed multifocal regions of low attenuation over the right temporal convexity, within the basal ganglia, inferior frontal lobe and corona radiata on the left side. Magnetic resonance imaging on the same day showed multiple areas of high signal on the FLAIR images, some of which contained central areas of low signal. There was no significant enhancement post gadolinium but several of the lesions showed increased signal on the diffusion-weighted images, reflecting cytotoxic oedema. Repeat CT showed an increase in the size of the cerebral lesions with haemorrhagic transformation of the right basal ganglia mass. A further lesion with a peripheral dense rim on the non-contrast images was identified in the right cerebellar hemisphere. The possibility of a vasculitis secondary to a fungal infection was raised. Two days later the patient became comatose with CT showing a large intracerebral haematoma in the left basal ganglia, intraventricular blood and hydrocephalus. The patient died soon afterwards. Post-mortem examination showed multifocal cerebral haemorrhage associated with necrotizing vasculitis and aspergillus infection

  16. Eosinophil Deficiency Compromises Lung Defense against Aspergillus fumigatus

    OpenAIRE

    Lilly, Lauren M.; Scopel, Michaella; Nelson, Michael P.; Burg, Ashley R.; Dunaway, Chad W; Steele, Chad

    2014-01-01

    Exposure to the mold Aspergillus fumigatus may result in allergic bronchopulmonary aspergillosis, chronic necrotizing pulmonary aspergillosis, or invasive aspergillosis (IA), depending on the host's immune status. Neutrophil deficiency is the predominant risk factor for the development of IA, the most life-threatening condition associated with A. fumigatus exposure. Here we demonstrate that in addition to neutrophils, eosinophils are an important contributor to the clearance of A. fumigatus f...

  17. Nutrient Environments Influence Competition among Aspergillus flavus Genotypes

    OpenAIRE

    Mehl, Hillary L.; Cotty, Peter J.

    2013-01-01

    The population dynamics of Aspergillus flavus, shaped in part by intraspecific competition, influence the likelihood and severity of crop aflatoxin contamination. Competition for nutrients may be one factor modulating intraspecific interactions, but the influences of specific types and concentrations of nutrients on competition between genotypes of A. flavus have not been investigated. Competition between paired A. flavus isolates on agar media was affected by varying concentrations of carbon...

  18. DECOLORIZATION OF BLUE 13 WITH ASPERGILLUS NIVEUS AND FUSARIUM MONILIFORME

    OpenAIRE

    Hülya KARACA; Merih KIVANÇ

    2012-01-01

    Depending on the changing world trends has been increasing interest in colored products. In the textile industry, to give the blue color to the textiles the heavily used Ambifiks Blue H5R (Blue 13) dye. This dye has been given from plants in the environment of the receiving water to results from the toxic effects. For reduction of this toxic effect has been isolated Aspergillus niveus and Fusarium moniliforme from porsuk Stream were invastigated because of decolorizasyon capabilities with dif...

  19. Modelling Aspergillus fumigatus infections in racing pigeons (Columba livia domestica)

    OpenAIRE

    Beernaert, Lies Angèle; Pasmans, Frank; Haesebrouck, Freddy; Martel, An

    2008-01-01

    Abstract In vivo modelling of aspergillosis in birds allows the evaluation of control measures and the study of host-pathogen interactions. In this study the impact of the use of different inoculation routes and immunosuppression on the course of an infection with Aspergillus fumigatus in racing pigeons (Columba livia domestica) was examined. A. fumigatus conidia were inoculated in the thoracic air sac, lung or trachea in immunocompetent or immunosuppressed pigeon squabs. Immunosup...

  20. Biotransformation of steviol derivatives by Aspergillus niger and Fusarium moniliforme

    International Nuclear Information System (INIS)

    Steviol derivatives have been submitted to biotransformations by fungi. Methyl ent-11β,13-dihydroxy-15,16-epoxikauran-19-oate was hydroxylated at C-11 by Aspergillus niger, whereas ent-16β-hydroxybeyeran-19-oic acid was hydroxylated at C-6 and C-7 by Fusarium moniliforme. The hydroxylation at non-activated positions at the carbon skeleton is discussed in connection with the properties of important polyhydroxylated diterpenoids described in the literature. (author)

  1. Pectinases of Aspergillus niger: A Molecular and Biochemical Characterisation

    OpenAIRE

    Parenicová, L.

    2000-01-01

    The major topics of this thesis are the microfilamentous fungus Aspergillus niger and the pectinases a group of extracellular enzymes. Many 'products' of this species hold the GRAS (Generally Regarded As Safe) status and thus pectinases find a broad range of applications in food, feed and beverage industries.Pectinases are enzymes which degrade pectin, a heteropolysaccharide found in the middle lamella and the primary cell wall of higher plants. The number of pectinase-encoding genes identifi...

  2. Voriconazole for the treatment of refractory Aspergillus fumigatus keratitis

    OpenAIRE

    Mehta, Hijab; Mehta, Hitendra B; Garg, Prashant; Kodial, Harish

    2008-01-01

    We report a case of Aspergillus fumigatus keratitis in a 53-year-old, well-controlled diabetic female who did not respond to standard antifungal treatment. She was started on topical natamycin eye drops, but the infiltrate continued to progress. Topical amphotericin B and systemic ketoconazole was added, however, there was no response and the infiltrate increased further. She was then switched to topical and systemic voriconazole. Steady resolution of the infiltrate was noted within 2 weeks o...

  3. Voriconazole for the treatment of refractory Aspergillus fumigatus keratitis

    Directory of Open Access Journals (Sweden)

    Mehta Hijab

    2008-01-01

    Full Text Available We report a case of Aspergillus fumigatus keratitis in a 53-year-old, well-controlled diabetic female who did not respond to standard antifungal treatment. She was started on topical natamycin eye drops, but the infiltrate continued to progress. Topical amphotericin B and systemic ketoconazole was added, however, there was no response and the infiltrate increased further. She was then switched to topical and systemic voriconazole. Steady resolution of the infiltrate was noted within 2 weeks of therapy.

  4. Diketopiperazines produced by an Aspergillus fumigatus Brazilian strain

    International Nuclear Information System (INIS)

    Seven diketopiperazines, corresponding to the cycles (L)-Pro-(L)-Phe, (L)-Pro-Gly, (L)-Pro- (L)-Pro, (L)-Pro-(L)-Val, (L)-4-OH-Pro-(L)-Leu, (L)-4-OH-Pro-(L)-Phe, and (L)-Pro-(L)-Leu, were isolated from the Aspergillus fumigatus fermentation broth. The relative and absolute stereochemistries were determined on the basis of NOESY experiments and by using a modified version of Marfey's method using HPLC, respectively. (author)

  5. Diketopiperazines produced by an Aspergillus fumigatus Brazilian strain

    Energy Technology Data Exchange (ETDEWEB)

    Furtado, Niege A.J.C; Pupo, Monica T.; Carvalho, Ivone; Campo, Vanessa L. Campo; Bastos, Jairo K. [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas]. E-mail: jkbastos@fcfrp.usp.br; Duarte, Marta Cristina T. [Universidade Estadual de Campinas, SP (Brazil). Centro Pluridisciplinar de Pesquisas Quimicas, Biologicas e Agricolas

    2005-11-15

    Seven diketopiperazines, corresponding to the cycles (L)-Pro-(L)-Phe, (L)-Pro-Gly, (L)-Pro- (L)-Pro, (L)-Pro-(L)-Val, (L)-4-OH-Pro-(L)-Leu, (L)-4-OH-Pro-(L)-Phe, and (L)-Pro-(L)-Leu, were isolated from the Aspergillus fumigatus fermentation broth. The relative and absolute stereochemistries were determined on the basis of NOESY experiments and by using a modified version of Marfey's method using HPLC, respectively. (author)

  6. A rare pigmented keratitis caused by Aspergillus fumigatus

    Institute of Scientific and Technical Information of China (English)

    Mauricio; Vélez; Kepa; Balparda; Ana; María; Díaz

    2015-01-01

    <正>Dear Sir,I am Mauricio Vélez,from the Department of Ophthalmology,Cornea Service Director,Universidad Pontificia Bolivariana in Medellín,Colombia.Below,I would like to share an interesting case I managed recently,which I’ve entitled"A rare pigmented keratitis caused by Aspergillus fumigatus".Fungi are a relatively uncommon cause of microbial keratitis

  7. Growth and production of amylotic enzymes by aspergillus spp

    OpenAIRE

    Murphy, Mary B.

    1987-01-01

    The growth and production of ©¿-amylase and amyloglucosidase by Aspergillus awamori NRRL 3112 and A. niger CBS 26265 were investigated, with a view to obtaining optimal levels of both these enzymes in shake flask culture, and subsequently on the large scale. The effect of various parameters, such as carbon source, nitrogen source, presence/absence of buffering agents, carbon:nitrogen ratio , pH values, and time were examined. Following the screening of ten strains of As...

  8. Aspergillus fumigatus-Related Species in Clinical Practice

    Science.gov (United States)

    Lamoth, Frédéric

    2016-01-01

    Aspergillus fumigatus is the main etiologic agent of invasive aspergillosis (IA). Other Aspergillus species belonging to the section Fumigati (A. fumigatus complex) may occasionally be the cause of IA. These strains are often misidentified, as they cannot be distinguished from A. fumigatus by conventional morphological analysis and sequencing methods. This lack of recognition may have important consequences as these A. fumigatus-related species often display some level of intrinsic resistance to azoles and other antifungal drugs. A. lentulus, A. udagawae, A. viridinutans, and A. thermomutatus (Neosartorya pseudofischeri) have been associated with refractory cases of IA. Microbiologists should be able to suspect the presence of these cryptic species behind a putative A. fumigatus isolate on the basis of some simple characteristics, such as defect in sporulation and/or unusual antifungal susceptibility profile. However, definitive species identification requires specific sequencing analyses of the beta-tubulin or calmodulin genes, which are not available in most laboratories. Multiplex PCR assays or matrix-assisted laser desorption ionization – time-of-flight mass spectrometry (MALDI-TOF MS) gave promising results for rapid and accurate distinction between A. fumigatus and other Aspergillus spp. of the section Fumigati in clinical practice. Improved diagnostic procedures and antifungal susceptibility testing may be helpful for the early detection and management of these particular IA cases.

  9. Acquired antifungal drug resistance in Aspergillus fumigatus: epidemiology and detection.

    Science.gov (United States)

    Howard, Susan Julie; Arendrup, Maiken Cavling

    2011-04-01

    Voriconazole is the recommended agent for invasive aspergillosis, with lipid amphotericin B or caspofungin as second line treatment choices. Being the only agents available in oral formulation, azoles are used in chronic infections and often over longer time periods. In addition to being used in clinical medicine, azoles are employed extensively in agriculture. Azole-resistant Aspergillus has been isolated in azole naïve patients, in azole exposed patients and in the environment. The primary underlying mechanism of resistance is as a result of alterations in the cyp51A target gene, with a variety of mutations found in clinical isolates but just one identified in a environmental strain (a point mutation at codon 98 accompanied by a tandem repeat in the promoter region). Much less is currently known about echinocandin resistance in Aspergillus, in part because susceptibility testing is not routinely performed and because the methods suffer from technical difficulties and suboptimal reproducibility. Clinical breakthrough cases have been reported however, and resistance has been confirmed in vivo. In this paper we review the current knowledge on epidemiology, susceptibility testing and underlying mechanisms involved in azole and echinocandin resistance in Aspergillus. PMID:20795765

  10. EFFECT OF GAMMA IRRADIATION AND ENVIRONMENTAL FACTORS ON -AMYLASE PRODUCTION BY ASPERGILLUS NIGER AND ASPERGILLUS ORYZAE FROM SOME AGRICULTURAL WASTES

    International Nuclear Information System (INIS)

    Amylases are one of the most important and oldest industrial enzymes. The optimization of production of α -amylase from Aspergillus niger and Aspergillus oryzae fungi, using different agro-wastes as sole carbon sources, was performed. The highest productivity of α -amylase by the two organisms was recorded at pH 6 and incubation temperature at 300C when the two organisms were grown on potato peels (PPs) and/or wheat straw (Ws) after days of cultivation. Pre-treated PPs and Ws with 20 kGy gave the best enzyme productivity by the two organisms compared with untreated ones. Also, exposing the inoculums of A. niger and A.oryzae to 0.5 and 0.75 kGy, respectively, led to enhancement of α-amylase to 48 and 46 μ/ml, respectively

  11. Aspergillus mulundensis sp. nov., a new species for the fungus producing the antifungal echinocandin lipopeptides, mulundocandins

    DEFF Research Database (Denmark)

    Bills, Gerald F.; Yue, Qun; Chen, Li;

    2016-01-01

    The invalidly published name Aspergillus sydowii var. mulundensis was proposed for a strain of Aspergillus that produced new echinocandin metabolites designated as the mulundocadins. Reinvestigation of this strain (Y-30462=DSMZ 5745) using phylogenetic, morphological, and metabolic data indicated...

  12. Phytase Production by Aspergillus niger CFR 335 and Aspergillus ficuum SGA 01 through Submerged and Solid-State Fermentation

    Directory of Open Access Journals (Sweden)

    Gunashree B. Shivanna

    2014-01-01

    Full Text Available Fermentation is one of the industrially important processes for the development of microbial metabolites that has immense applications in various fields. This has prompted to employ fermentation as a major technique in the production of phytase from microbial source. In this study, a comparison was made between submerged (SmF and solid-state fermentations (SSF for the production of phytase from Aspergillus niger CFR 335 and Aspergillus ficuum SGA 01. It was found that both the fungi were capable of producing maximum phytase on 5th day of incubation in both submerged and solid-state fermentation media. Aspergillus niger CFR 335 and A. ficuum produced a maximum of 60.6 U/gds and 38 U/gds of the enzyme, respectively, in wheat bran solid substrate medium. Enhancement in the enzyme level (76 and 50.7 U/gds was found when grown in a combined solid substrate medium comprising wheat bran, rice bran, and groundnut cake in the ratio of 2 : 1 : 1. A maximum of 9.6 and 8.2 U/mL of enzyme activity was observed in SmF by A. niger CFR 335 and A.ficuum, respectively, when grown in potato dextrose broth.

  13. Nonfunctionality of Aspergillus sojae aflR in a strain of Aspergillus parasiticus with a disrupted aflR gene.

    Science.gov (United States)

    Takahashi, Tadashi; Chang, Perng-Kuang; Matsushima, Kenichiro; Yu, Jiujiang; Abe, Keietsu; Bhatnagar, Deepak; Cleveland, Thomas E; Koyama, Yasuji

    2002-08-01

    Aspergillus sojae belongs to the Aspergillus section Flavi but does not produce aflatoxins. The functionality of the A. sojae aflR gene (aflRs) was examined by transforming it into an DeltaaflR strain of A. parasiticus, derived from a nitrate-nonutilizing, versicolorin A (VERA)-accumulating strain. The A. parasiticus aflR gene (aflRp) transformants produced VERA, but the aflRs transformants did not. Even when aflRs was placed under the control of the amylase gene (amyB) promoter of Aspergillus oryzae, the amy(p)::aflRs transformants did not produce VERA. A chimeric construct containing the aflRs promoter plus the aflRs N- and aflRp C-terminal coding regions could restore VERA production, but a construct containing the aflRp promoter plus the aflRp N- and aflRs C-terminal coding regions could not. These results show that the A. sojae aflR promoter is functional in A. parasiticus and that the HAHA motif does not affect the function of the resulting hybrid AflR. We conclude that the lack of aflatoxin production by A. sojae can be attributed, at least partially, to the premature termination defect in aflRs, which deletes the C-terminal transcription activation domain that is critical for the expression of aflatoxin biosynthetic genes. PMID:12147467

  14. Discovery and analysis of an active long terminal repeat-retrotransposable element in Aspergillus oryzae.

    Science.gov (United States)

    Jie Jin, Feng; Hara, Seiichi; Sato, Atsushi; Koyama, Yasuji

    2014-01-01

    Wild-type Aspergillus oryzae RIB40 contains two copies of the AO090005001597 gene. We previously constructed A. oryzae RIB40 strain, RKuAF8B, with multiple chromosomal deletions, in which the AO090005001597 copy number was found to be increased significantly. Sequence analysis indicated that AO090005001597 is part of a putative 6,000-bp retrotransposable element, flanked by two long terminal repeats (LTRs) of 669 bp, with characteristics of retroviruses and retrotransposons, and thus designated AoLTR (A. oryzae LTR-retrotransposable element). AoLTR comprised putative reverse transcriptase, RNase H, and integrase domains. The deduced amino acid sequence alignment of AoLTR showed 94% overall identity with AFLAV, an A. flavus Tf1/sushi retrotransposon. Quantitative real-time RT-PCR showed that AoLTR gene expression was significantly increased in the RKuAF8B, in accordance with the increased copy number. Inverse PCR indicated that the full-length retrotransposable element was randomly integrated into multiple genomic locations. However, no obvious phenotypic changes were associated with the increased AoLTR gene copy number. PMID:24646755

  15. Expanding the chemical space for natural products by Aspergillus-Streptomyces co-cultivation and biotransformation.

    Science.gov (United States)

    Wu, Changsheng; Zacchetti, Boris; Ram, Arthur F J; van Wezel, Gilles P; Claessen, Dennis; Hae Choi, Young

    2015-01-01

    Actinomycetes and filamentous fungi produce a wide range of bioactive compounds, with applications as antimicrobials, anticancer agents or agrochemicals. Their genomes contain a far larger number of gene clusters for natural products than originally anticipated, and novel approaches are required to exploit this potential reservoir of new drugs. Here, we show that co-cultivation of the filamentous model microbes Streptomyces coelicolor and Aspergillus niger has a major impact on their secondary metabolism. NMR-based metabolomics combined with multivariate data analysis revealed several compounds that correlated specifically to co-cultures, including the cyclic dipeptide cyclo(Phe-Phe) and 2-hydroxyphenylacetic acid, both of which were produced by A. niger in response to S. coelicolor. Furthermore, biotransformation studies with o-coumaric acid and caffeic acid resulted in the production of the novel compounds (E)-2-(3-hydroxyprop-1-en-1-yl)-phenol and (2E,4E)-3-(2-carboxy-1-hydroxyethyl)-2,4-hexadienedioxic acid, respectively. This highlights the utility of microbial co-cultivation combined with NMR-based metabolomics as an efficient pipeline for the discovery of novel natural products. PMID:26040782

  16. RNA-Seq Reveals OTA-Related Gene Transcriptional Changes in Aspergillus carbonarius.

    Directory of Open Access Journals (Sweden)

    Donato Gerin

    Full Text Available Ochratoxin A (OTA is a mycotoxin harmful for animals and humans. Aspergillus carbonarius is the main responsible for OTA contamination of grapes and derived products. Gene transcriptional profiling of 4 A. carbonarius strains was carried out by RNA-Seq analysis to study transcriptome changes associated with OTA production. By comparing OTA inducing (OTAI vs. non-inducing (OTAN cultural conditions, a total of 3,705 differentially expressed genes (DEGs (fold change > |2| and FDR ≤ 0.05 were identified. Several genes involved in primary metabolic processes, with particular regard to carbohydrate and amino acid metabolisms, secondary metabolic processes, transport, response to stress and sporulation were up-regulated by OTAI conditions at all the analysed sampling times (4, 6 and 8 DAI or starting from 6 DAI. Highly up-regulated DEGs encoding enzymes involved in biosynthesis of secondary metabolites, oxidoreductases, transporters and transcription factors were examined for their potential involvement in OTA biosynthesis and related metabolic pathways. Differential expression of genes encoding polyketide synthases (pks, non-ribosomal peptide synthetases (nrps and chloroperoxidase (cpo was validated by RT-qPCR. Among clusters of co-regulated genes involved in SM biosynthesis, one putative OTA-gene cluster, including both pks and nrps genes, was detected in the A. carbonarius genome.

  17. RNA-Seq Reveals OTA-Related Gene Transcriptional Changes in Aspergillus carbonarius.

    Science.gov (United States)

    Gerin, Donato; De Miccolis Angelini, Rita M; Pollastro, Stefania; Faretra, Francesco

    2016-01-01

    Ochratoxin A (OTA) is a mycotoxin harmful for animals and humans. Aspergillus carbonarius is the main responsible for OTA contamination of grapes and derived products. Gene transcriptional profiling of 4 A. carbonarius strains was carried out by RNA-Seq analysis to study transcriptome changes associated with OTA production. By comparing OTA inducing (OTAI) vs. non-inducing (OTAN) cultural conditions, a total of 3,705 differentially expressed genes (DEGs) (fold change > |2| and FDR ≤ 0.05) were identified. Several genes involved in primary metabolic processes, with particular regard to carbohydrate and amino acid metabolisms, secondary metabolic processes, transport, response to stress and sporulation were up-regulated by OTAI conditions at all the analysed sampling times (4, 6 and 8 DAI) or starting from 6 DAI. Highly up-regulated DEGs encoding enzymes involved in biosynthesis of secondary metabolites, oxidoreductases, transporters and transcription factors were examined for their potential involvement in OTA biosynthesis and related metabolic pathways. Differential expression of genes encoding polyketide synthases (pks), non-ribosomal peptide synthetases (nrps) and chloroperoxidase (cpo) was validated by RT-qPCR. Among clusters of co-regulated genes involved in SM biosynthesis, one putative OTA-gene cluster, including both pks and nrps genes, was detected in the A. carbonarius genome. PMID:26765536

  18. RNA-Seq Reveals OTA-Related Gene Transcriptional Changes in Aspergillus carbonarius

    Science.gov (United States)

    Gerin, Donato; De Miccolis Angelini, Rita M.; Pollastro, Stefania; Faretra, Francesco

    2016-01-01

    Ochratoxin A (OTA) is a mycotoxin harmful for animals and humans. Aspergillus carbonarius is the main responsible for OTA contamination of grapes and derived products. Gene transcriptional profiling of 4 A. carbonarius strains was carried out by RNA-Seq analysis to study transcriptome changes associated with OTA production. By comparing OTA inducing (OTAI) vs. non-inducing (OTAN) cultural conditions, a total of 3,705 differentially expressed genes (DEGs) (fold change > |2| and FDR ≤ 0.05) were identified. Several genes involved in primary metabolic processes, with particular regard to carbohydrate and amino acid metabolisms, secondary metabolic processes, transport, response to stress and sporulation were up-regulated by OTAI conditions at all the analysed sampling times (4, 6 and 8 DAI) or starting from 6 DAI. Highly up-regulated DEGs encoding enzymes involved in biosynthesis of secondary metabolites, oxidoreductases, transporters and transcription factors were examined for their potential involvement in OTA biosynthesis and related metabolic pathways. Differential expression of genes encoding polyketide synthases (pks), non-ribosomal peptide synthetases (nrps) and chloroperoxidase (cpo) was validated by RT-qPCR. Among clusters of co-regulated genes involved in SM biosynthesis, one putative OTA-gene cluster, including both pks and nrps genes, was detected in the A. carbonarius genome. PMID:26765536

  19. Expression and characterization of a cutinase (AnCUT2 from Aspergillus niger

    Directory of Open Access Journals (Sweden)

    Ahmed Al-Tammar Khadijah

    2016-03-01

    Full Text Available Cutin hydrolase (EC 3.1.1.74, an extracellular polyesterase found in pollens, bacteria and fungi, is an efficient catalyst that exhibits hydrolytic activity on a variety of water-soluble esters, synthetic fibers, plastics and triglycerides. Thus, cutinase can be used in various applications such as ester synthesis, bio-scouring, food and detergent industries. Ancut2 is one of five genes encoding cutinases present in the Aspergillus niger ATCC 10574 genome. The cDNA of Ancut2 comprising of an open reading frame of 816 bp encoding a protein of 271 amino acid residues, was isolated and expressed in Pichia pastoris. The partially purified recombinant cutinase exhibited a molecular mass of approximately 40 kDa. The enzyme showed highest activity at 40°C with a preference for acidic pH (5.0-6.0. AnCUT2 showed hydrolytic activity towards various p-nitrophenyl esters with preference towards shorter chain esters such as p-nitrophenyl butyrate (C4. Scanning Electron Microscopy demonstrated that AnCUT2 was capable of modifying surfaces of synthetic polycaprolactone and polyethylene terephthalate plastics. The properties of this enzyme suggest that it may be applied in synthetic fiber modification and fruit processing industries.

  20. 302 Screening for Allergic Bronchopulmonary Aspergillosis in Patients with Aspergillus + Asthma From 2000 to 2010

    OpenAIRE

    Greenberger, Paul

    2012-01-01

    Background Approximately 25% of patients with persistent asthma have immediate skin reactivity to Aspergillus species. The purpose of this study was to screen all patients with immediate hypersensitivity to Aspergillus for evidence of Allergic Bronchopulmonary Aspergillosis (ABPA). Methods All patients with asthma underwent immediate cutaneous testing including prick (epicutaneous) with a mix of Aspergillus species and if negative, intradermal at 1000 PNU/mL, Aspergillus fumigatus (Af). Sera ...