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Jens Christian Frisvad - One of the best experts on this subject based on the ideXlab platform.
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distribution of sterigmatocystin in filamentous fungi
Fungal Biology, 2011Co-Authors: Christian Rank, Janos Varga, R A Samson, Kristian Fog Nielsen, Thomas Ostenfeld Larsen, Jens Christian FrisvadAbstract:Abstract During the last 50 y, the carcinogenic mycotoxin sterigmatocystin (ST) has been reported in several phylogenetically and phenotypically different genera: Aschersonia, Aspergillus, Bipolaris, Botryotrichum, Chaetomium, Emericella, Eurotium, Farrowia, Fusarium, Humicola, Moelleriella, Monocillium and Podospora. We have reexamined all available strains of the original producers, in addition to ex type and further strains of each species reported to produce ST and the biosynthetically derived aflatoxins. We also screened strains of all available species in Penicillium and Aspergillus for ST and aflatoxin. Six new ST producing fungi were discovered: Aspergillus asperescens, Aspergillus aureolatus, Aspergillus eburneocremeus, Aspergillus protuberus, Aspergillus tardus, and Penicillium inflatum and one new aflatoxin producer: Aspergillus togoensis (=Stilbothamnium togoense). ST was confirmed in 23 Emericella, four Aspergillus, five Chaetomium, one Botryotrichum and one Humicola species grown on a selection of secondary metabolite inducing media, and using multiple detection methods: HPLC–UV/Vis DAD, – HRMS and – MS/MS. The immediate precursor for aflatoxin, O-methylsterigmatocystin was found in Chaetomium cellulolyticum, Chaetomium longicolleum, Chaetomium malaysiense and Chaetomium virescens, but aflatoxin was not detected from any Chaetomium species. In all 55 species, representing more than 11 clades throughout the Pezizomycotina, can be reliably claimed to be ST producers and 13 of these can also produce aflatoxins. It is not known yet whether the ST/aflatoxin pathway has been developed independently 11 times, or is the result of partial horizontal gene transfer.
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taxonomic comparison of three different groups of aflatoxin producers and a new efficient producer of aflatoxin b1 sterigmatocystin and 3 o methylsterigmatocystin aspergillus rambellii sp nov
Systematic and Applied Microbiology, 2005Co-Authors: Jens Christian Frisvad, Pernille Skouboe, Robert A SamsonAbstract:Abstract Accumulation of the carcinogenic mycotoxin aflatoxin B 1 has been reported from members of three different groups of Aspergilli (4) Aspergillus flavus, A. flavus var. parvisclerotigenus, A. parasiticus , A. toxicarius , A. nomius , A. pseudotamarii , A. zhaoqingensis , A. bombycis and from the ascomycete genus Petromyces ( Aspergillus section Flavi ), (2) Emericella astellata and E. venezuelensis from the ascomycete genus Emericella ( Aspergillus section Nidulantes ) and (3) Aspergillus ochraceoroseus from a new section proposed here: Aspergillus section Ochraceorosei . We here describe a new species, A. rambellii referable to Ochraceorosei , that accumulates very large amounts of sterigmatocystin, 3- O -methylsterigmatocystin and aflatoxin B 1 , but not any of the other known extrolites produced by members of Aspergillus section Flavi or Nidulantes . G type aflatoxins were only found in some of the species in Aspergillus section Flavi , while the B type aflatoxins are common in all three groups. Based on the cladistic analysis of nucleotide sequences of ITS1 and 2 and 5.8S, it appears that type G aflatoxin producers are paraphyletic and that section Ochraceorosei is a sister group to the sections Flavi, Circumdati and Cervini , with Emericella species being an outgroup to these sister groups. All aflatoxin producing members of section Flavi produce kojic acid and most species, except A. bombycis and A. pseudotamarii, produce aspergillic acid. Species in Flavi, that produce B type aflatoxins, but not G type aflatoxins, often produced cyclopiazonic acid. No strain was found which produce both G type aflatoxins and cyclopiazonic acid. It was confirmed that some strains of A. flavus var. columnaris produce aflatoxin B 2 , but this extrolite was not detected in the ex type strain of that variety. A. flavus var. parvisclerotigenus is raised to species level based on the specific combination of small sclerotia, profile of extrolites and rDNA sequence differences. A. zhaoqingensis is regarded as a synonym of A. nomius, while A. toxicarius resembles A. parasiticus but differs with at least three base pair differences. At least 10 Aspergillus species can be recognized which are able to biosynthesize aflatoxins, and they are placed in three very different clades.
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Emericella venezuelensis a new species with stellate ascospores producing sterigmatocystin and aflatoxin b1
Systematic and Applied Microbiology, 2004Co-Authors: Jens Christian Frisvad, R A SamsonAbstract:Summary Emericella venezuelensis is a new species, differing from two other species with stellate ascospores, E. variecolor and E. pluriseminata, by triangular flaps on the convex sides of the ascospores, and further from E. variecolor by producing an Aspergillus anamorph only on unconventional growth media. The three species also differ in their profiles of extrolites (secondary metabolites). Emericella venezuelensis produces aflatoxin B1, sterigmatocystin, and terrein and compounds with chromophores of the shamixanthone, emerin and desertorin type of compounds. E. variecolor produces asteltoxin, shamixanthone, asperthecin, and terrein, in addition to metabolites unequivocally recorded in the literature or tentatively identified here as astellolide A & B, andibenin A, B, C, andilesin A, B, C, anditomin, astellatol, stellatic acid, stellatin, tajixanthone, radixanthone, najamxanthone, ajamxanthone, variecoxanthone A, B, C, isoemericellin, kojic acid, varitriol, varioxiran, dihydroterrein, 7-hydroxyemodin, avariquinone and stromemycin. E. pluriseminata produces several unknown specific extrolites. E. venezuelensis is the first organism of marine origin reported to produce aflatoxin. Aflatoxin production by E. venezuelensis makes this species an attractive model organism for the study of the regulation of this important type of carcinogenic mycotoxins in combination with the knowledge on sterigmatocystin production by E. nidulans, soon to be whole genome sequenced. The isolates were also analyzed cladistically using partial sequences of the β-tubulin gene. Since three species of Emericella have stellate ascospores, and the type material of E. variecolor is equivocal, this species is epitypified with CBS 598.65. Emericella species normally do not appear to cause problems for food safety, as they are most often found in litter and soil.
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Emericella astellata, a new producer of aflatoxin B1, B2 and sterigmatocystin
Letters in applied microbiology, 2004Co-Authors: Jens Christian Frisvad, Robert A Samson, Jørn SmedsgaardAbstract:J . C . F R I S V A D , R . A . S A M S O N A N D J . S M E D S G A A R D . 2004. Aims: To report on aflatoxin B1 and B2 production from a species of Emericella. Methods and Results: Aflatoxins and sterigmatocystin were determined by high-pressure liquid chromatography (HPLC) with diode array detection and confirmed by HPLC with mass spectrometry detection. Among 30 known species of Emericella only one species produced aflatoxin. Strains originating from the same geographical source material had different patterns of aflatoxin and sterigmatocystin production on different media, indicating that epigenetic factors may be involved in the regulation of aflatoxin production. However, two cultures from the same original genet were very similar. Conclusions: Emericella astellata can produce small amounts of sterigmatocystin and aflatoxin B1 and B2. Significance and Impact of the Study: Emericella has been used extensively in genetic studies and therefore the isolates producing aflatoxin can be used to elucidate the genetic, evolutionary and maybe ecological role of aflatoxins using molecular genetic methods.
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fungal depside guisinol from a marine derived strain of Emericella unguis
Phytochemistry, 1999Co-Authors: Joan Nielsen, Per Halfdan Nielsen, Jens Christian FrisvadAbstract:Abstract A marine isolate of the fungus Emericella unguis gave a new antibacterial depside, guisinol (1). The structure determination was based on mass spectrometry and NMR spectroscopical studies. Structurally 1 resembles the depsidones emeguisin A→C previously isolated from another strain of the same species. Five other isolates of E. unguis also produced the same qualitative profile of secondary metabolites including guisinol and dechloronidulin. Other species of Emericella did not produce any of these compounds and they are thus of chemotaxonomic significance.
Josep Guarro - One of the best experts on this subject based on the ideXlab platform.
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Onychomycosis Due to Emericella quadrilineata
Journal of clinical microbiology, 2004Co-Authors: Harish C. Gugnani, Vk Vijayan, Puneet Tyagi, Sonal Sharma, Alberto M. Stchigel, Josep GuarroAbstract:Nondermatophytic fungi are increasingly being reported as etiological agents of onychomycosis. We describe here a case of hand nail infection caused by Emericella quadrilineata (anamorph Aspergillus tetrazonus), a species not so far known to be an etiological agent of onychomycosis.
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A new species of Emericella and a rare morphological variant of E. quadrilineata
Mycological Research, 1999Co-Authors: A.m. Stchigel, Joan Cano, Josep GuarroAbstract:Emericella indica sp. nov. and a peculiar morphological variant of E. quadrilineata are described and illustrated. The former is characterized by large, smooth, violet ascospores and the latter by apparently budding ascospores. Analysis of the sequences of the nuclear rDNA ITS region gene of these species and E. nidulans and E. variecolor support our concepts based on morphological criteria.
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A new species of Emericella from Indian soil
Mycologia, 1997Co-Authors: Alberto M. Stchigel, Josep GuarroAbstract:Emericella pluriseminata sp. nov. (Euro- tiales, Ascomycota), isolated from Indian soil, is de- scribed and illustrated. It differs from the other spe- cies of the genus by having ascomata appearing very late, 16-spored asci, large, stellate, violet-brown asco- spores and in lacking an anamorph.
R A Samson - One of the best experts on this subject based on the ideXlab platform.
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distribution of sterigmatocystin in filamentous fungi
Fungal Biology, 2011Co-Authors: Christian Rank, Janos Varga, R A Samson, Kristian Fog Nielsen, Thomas Ostenfeld Larsen, Jens Christian FrisvadAbstract:Abstract During the last 50 y, the carcinogenic mycotoxin sterigmatocystin (ST) has been reported in several phylogenetically and phenotypically different genera: Aschersonia, Aspergillus, Bipolaris, Botryotrichum, Chaetomium, Emericella, Eurotium, Farrowia, Fusarium, Humicola, Moelleriella, Monocillium and Podospora. We have reexamined all available strains of the original producers, in addition to ex type and further strains of each species reported to produce ST and the biosynthetically derived aflatoxins. We also screened strains of all available species in Penicillium and Aspergillus for ST and aflatoxin. Six new ST producing fungi were discovered: Aspergillus asperescens, Aspergillus aureolatus, Aspergillus eburneocremeus, Aspergillus protuberus, Aspergillus tardus, and Penicillium inflatum and one new aflatoxin producer: Aspergillus togoensis (=Stilbothamnium togoense). ST was confirmed in 23 Emericella, four Aspergillus, five Chaetomium, one Botryotrichum and one Humicola species grown on a selection of secondary metabolite inducing media, and using multiple detection methods: HPLC–UV/Vis DAD, – HRMS and – MS/MS. The immediate precursor for aflatoxin, O-methylsterigmatocystin was found in Chaetomium cellulolyticum, Chaetomium longicolleum, Chaetomium malaysiense and Chaetomium virescens, but aflatoxin was not detected from any Chaetomium species. In all 55 species, representing more than 11 clades throughout the Pezizomycotina, can be reliably claimed to be ST producers and 13 of these can also produce aflatoxins. It is not known yet whether the ST/aflatoxin pathway has been developed independently 11 times, or is the result of partial horizontal gene transfer.
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Emericella venezuelensis a new species with stellate ascospores producing sterigmatocystin and aflatoxin b1
Systematic and Applied Microbiology, 2004Co-Authors: Jens Christian Frisvad, R A SamsonAbstract:Summary Emericella venezuelensis is a new species, differing from two other species with stellate ascospores, E. variecolor and E. pluriseminata, by triangular flaps on the convex sides of the ascospores, and further from E. variecolor by producing an Aspergillus anamorph only on unconventional growth media. The three species also differ in their profiles of extrolites (secondary metabolites). Emericella venezuelensis produces aflatoxin B1, sterigmatocystin, and terrein and compounds with chromophores of the shamixanthone, emerin and desertorin type of compounds. E. variecolor produces asteltoxin, shamixanthone, asperthecin, and terrein, in addition to metabolites unequivocally recorded in the literature or tentatively identified here as astellolide A & B, andibenin A, B, C, andilesin A, B, C, anditomin, astellatol, stellatic acid, stellatin, tajixanthone, radixanthone, najamxanthone, ajamxanthone, variecoxanthone A, B, C, isoemericellin, kojic acid, varitriol, varioxiran, dihydroterrein, 7-hydroxyemodin, avariquinone and stromemycin. E. pluriseminata produces several unknown specific extrolites. E. venezuelensis is the first organism of marine origin reported to produce aflatoxin. Aflatoxin production by E. venezuelensis makes this species an attractive model organism for the study of the regulation of this important type of carcinogenic mycotoxins in combination with the knowledge on sterigmatocystin production by E. nidulans, soon to be whole genome sequenced. The isolates were also analyzed cladistically using partial sequences of the β-tubulin gene. Since three species of Emericella have stellate ascospores, and the type material of E. variecolor is equivocal, this species is epitypified with CBS 598.65. Emericella species normally do not appear to cause problems for food safety, as they are most often found in litter and soil.
Alexandre Alanio - One of the best experts on this subject based on the ideXlab platform.
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Iterative breakthrough invasive aspergillosis due to TR(34) /L98H azole-resistant Aspergillus fumigatus and Emericella sublata in a single hematopoietic stem cell transplant patient
Transplant Infectious Disease: An Official Journal of the Transplantation Society, 2014Co-Authors: F. S. Fontbrune, B. Denis, M. Meunier, D. Garcia-hermoso, S. Bretagne, Alexandre AlanioAbstract:We report 3 consecutive episodes of invasive aspergillosis in a single hematopoietic stem cell transplant patient successively attributed to TR(34) /L98H azole-resistant Aspergillus fumigatus and to a first occurrence of invasive Emericella sublata infection. This case illustrates potential selection of resistant molds during antifungal therapy in hematological patient.
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Iterative breakthrough invasive aspergillosis due to TR(34)/L98H azole‐resistant Aspergillus fumigatus and Emericella sublata in a single hematopoietic stem cell transplant patient
Transplant infectious disease : an official journal of the Transplantation Society, 2014Co-Authors: F. S. Fontbrune, B. Denis, M. Meunier, D. Garcia-hermoso, S. Bretagne, Alexandre AlanioAbstract:We report 3 consecutive episodes of invasive aspergillosis in a single hematopoietic stem cell transplant patient successively attributed to TR(34) /L98H azole-resistant Aspergillus fumigatus and to a first occurrence of invasive Emericella sublata infection. This case illustrates potential selection of resistant molds during antifungal therapy in hematological patient.
Wenhan Lin - One of the best experts on this subject based on the ideXlab platform.
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Diasteltoxins A–C, Asteltoxin-Based Dimers from a Mutant of the Sponge-Associated Emericella variecolor Fungus
Organic letters, 2016Co-Authors: Hailin Long, Zhongbin Cheng, Wei Huang, Jingrong Cui, Peter Proksch, Wenhan LinAbstract:Three novel asteltoxin-bearing dimers namely diasteltoxins A–C (1–3) along with asteltoxin were isolated from a mutated strain of a sponge-derived fungus Emericella variecolor XSA-07-2. Their structures were determined by extensive spectroscopic analyses including the computed electronic circular dichroism (ECD) data for the configurational assignment. The biogenetic formation of the dimers through [2 + 2] cycloaddition of asteltoxin was postulated. Diasteltoxins 1–3 exerted inhibitory effects against the tumor cell lines H1299 and MCF7 and exhibited significant inhibition against thioredoxin reductase (TrxR).
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Diasteltoxins A–C, Asteltoxin-Based Dimers from a Mutant of the Sponge-Associated Emericella variecolor Fungus
2016Co-Authors: Hailin Long, Zhongbin Cheng, Wei Huang, Jingrong Cui, Peter Proksch, Wenhan LinAbstract:Three novel asteltoxin-bearing dimers namely diasteltoxins A–C (1–3) along with asteltoxin were isolated from a mutated strain of a sponge-derived fungus Emericella variecolor XSA-07-2. Their structures were determined by extensive spectroscopic analyses including the computed electronic circular dichroism (ECD) data for the configurational assignment. The biogenetic formation of the dimers through [2 + 2] cycloaddition of asteltoxin was postulated. Diasteltoxins 1–3 exerted inhibitory effects against the tumor cell lines H1299 and MCF7 and exhibited significant inhibition against thioredoxin reductase (TrxR)