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1.
Antonie Van Leeuwenhoek ; 117(1): 53, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38483617

RESUMO

The genus Sporendonema (Gymnoascaceae, Onygenales) was introduced in 1827 with the type species S. casei for a red mould on cheese. Cheese is a consistent niche for this species. Sphaerosporium equinum is another species classified in Gymnoascaceae and has also been reported from cheese. Recently, other habitats have been reported for both Sporendonema casei and Sphaerosporium equinum. The present study aimed to investigate the taxonomy of Sporendonema and Sphaerosporium, as well as a close neighbour, Arachniotus. Two strains of Hormiscium aurantiacum, another related cheese-associated species were also included in the analyses. Strains were evaluated in terms of macro- and micromorphology, physiology including salt tolerance, growth rate at different temperatures, casein degradation, cellulase activity, lipolytic activity, and multi-locus phylogeny with sequences of the nuclear ribosomal internal transcribed spacer region, the D1-D2 region of the large subunit and partial ß-tubulin locus sequences. The results showed that the analysed species were congeneric, and the generic names Arachniotus and Sphaerosporium should be reduced to the synonymy of Sporendonema. Therefore, four new combinations as well as one lectotype and one epitype were designated in Sporendonema. Two strains attributed to Sphaerosporium equinum from substrates other than cheese were found to be phylogenetically and morphologically deviant and were introduced as a new species named Sporendonema isthmoides.


Assuntos
Ascomicetos , Filogenia , DNA Espaçador Ribossômico
2.
Toxins (Basel) ; 16(2)2024 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-38393177

RESUMO

Fusarium is a genus that mostly consists of plant pathogenic fungi which are able to produce a broad range of toxic secondary metabolites. In this study, we focus on a type A trichothecene-producing isolate (15-39) of Fusarium sporotrichioides from Lower Austria. We assessed the secondary metabolite profile and optimized the toxin production conditions on autoclaved rice and found that in addition to large amounts of T-2 and HT-2 toxins, this strain was able to produce HT-2-glucoside. The optimal conditions for the production of T-2 toxin, HT-2 toxin, and HT-2-glucoside on autoclaved rice were incubation at 12 °C under constant light for four weeks, darkness at 30 °C for two weeks, and constant light for three weeks at 20 °C, respectively. The HT-2-glucoside was purified, and the structure elucidation by NMR revealed a mixture of two alpha-glucosides, presumably HT-2-3-O-alpha-glucoside and HT-2-4-O-alpha-glucoside. The efforts to separate the two compounds by HPLC were unsuccessful. No hydrolysis was observed with two the alpha-glucosidases or with human salivary amylase and Saccharomyces cerevisiae maltase. We propose that the two HT-2-alpha-glucosides are not formed by a glucosyltransferase as they are in plants, but by a trans-glycosylating alpha-glucosidase expressed by the fungus on the starch-containing rice medium.


Assuntos
Fusarium , Micotoxinas , Oryza , Toxina T-2/análogos & derivados , Humanos , Glucosídeos/metabolismo , Fusarium/metabolismo , Oryza/metabolismo , Micotoxinas/metabolismo
3.
Fungal Biol Biotechnol ; 10(1): 13, 2023 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-37355668

RESUMO

BACKGROUND: Fungi are important sources for bioactive compounds that find their applications in many important sectors like in the pharma-, food- or agricultural industries. In an environmental monitoring project for fungi involved in soil nitrogen cycling we also isolated Cephalotrichum gorgonifer (strain NG_p51). In the course of strain characterisation work we found that this strain is able to naturally produce high amounts of rasfonin, a polyketide inducing autophagy, apoptosis, necroptosis in human cell lines and showing anti-tumor activity in KRAS-dependent cancer cells. RESULTS: In order to elucidate the biosynthetic pathway of rasfonin, the strain was genome sequenced, annotated, submitted to transcriptome analysis and genetic transformation was established. Biosynthetic gene cluster (BGC) prediction revealed the existence of 22 BGCs of which the majority was not expressed under our experimental conditions. In silico prediction revealed two BGCs with a suite of enzymes possibly involved in rasfonin biosynthesis. Experimental verification by gene-knock out of the key enzyme genes showed that one of the predicted BGCs is indeed responsible for rasfonin biosynthesis. CONCLUSIONS: This study identified a biosynthetic gene cluster containing a key-gene responsible for rasfonin production. Additionally, molecular tools were established for the non-model fungus Cephalotrichum gorgonifer which allows strain engineering and heterologous expression of the BGC for high rasfonin producing strains and the biosynthesis of rasfonin derivates for diverse applications.

4.
Microbiol Spectr ; : e0332622, 2023 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-36802215

RESUMO

Candida glabrata is a human-associated opportunistic fungal pathogen. It shares its niche with Lactobacillus spp. in the gastrointestinal and vaginal tract. In fact, Lactobacillus species are thought to competitively prevent Candida overgrowth. We investigated the molecular aspects of this antifungal effect by analyzing the interaction of C. glabrata strains with Limosilactobacillus fermentum. From a collection of clinical C. glabrata isolates, we identified strains with different sensitivities to L. fermentum in coculture. We analyzed the variation of their expression pattern to isolate the specific response to L. fermentum. C. glabrata-L. fermentum coculture induced genes associated with ergosterol biosynthesis, weak acid stress, and drug/chemical stress. L. fermentum coculture depleted C. glabrata ergosterol. The reduction of ergosterol was dependent on the Lactobacillus species, even in coculture with different Candida species. We found a similar ergosterol-depleting effect with other lactobacillus strains (Lactobacillus crispatus and Lactobacillus rhamosus) on Candida albicans, Candida tropicalis, and Candida krusei. The addition of ergosterol improved C. glabrata growth in the coculture. Blocking ergosterol synthesis with fluconazole increased the susceptibility against L. fermentum, which was again mitigated by the addition of ergosterol. In accordance, a C. glabrata Δerg11 mutant, defective in ergosterol biosynthesis, was highly sensitive to L. fermentum. In conclusion, our analysis indicates an unexpected direct function of ergosterol for C. glabrata proliferation in coculture with L. fermentum. IMPORTANCE The yeast Candida glabrata, an opportunistic fungal pathogen, and the bacterium Limosilactobacillus fermentum both inhabit the human gastrointestinal and vaginal tract. Lactobacillus species, belonging to the healthy human microbiome, are thought to prevent C. glabrata infections. We investigated the antifungal effect of Limosilactobacillus fermentum on C. glabrata strains quantitively in vitro. The interaction between C. glabrata and L. fermentum evokes an upregulation of genes required for the synthesis of ergosterol, a sterol constituent of the fungal plasma membrane. We found a dramatic reduction of ergosterol in C. glabrata when it was exposed to L. fermentum. This effect extended to other Candida species and other Lactobacillus species. Furthermore, fungal growth was efficiently suppressed by a combination of L. fermentum and fluconazole, an antifungal drug which inhibits ergosterol synthesis. Thus, fungal ergosterol is a key metabolite for the suppression of C. glabrata by L. fermentum.

5.
Environ Microbiol ; 24(10): 4899-4914, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35848075

RESUMO

Co-culturing the bacterium Streptomyces rapamycinicus and the ascomycete Aspergillus nidulans has previously been shown to trigger the production of orsellinic acid (ORS) and its derivates in the fungal cells. Based on these studies it was assumed that direct physical contact is a prerequisite for the metabolic reaction that involves a fungal amino acid starvation response and activating chromatin modifications at the biosynthetic gene cluster (BGC). Here we show that not physical contact, but a guanidine containing macrolide, named polaramycin B, triggers the response. The substance is produced constitutively by the bacterium and above a certain concentration, provokes the production of ORS. In addition, several other secondary metabolites were induced by polaramycin B. Our genome-wide transcriptome analysis showed that polaramycin B treatment causes downregulation of fungal genes necessary for membrane stability, general metabolism and growth. A compensatory genetic response can be observed in the fungus that included upregulation of BGCs and genes necessary for ribosome biogenesis, translation and membrane stability. Our work discovered a novel chemical communication, in which the antifungal bacterial metabolite polaramycin B leads to the production of antibacterial defence chemicals and to the upregulation of genes necessary to compensate for the cellular damage caused by polaramycin B.


Assuntos
Aspergillus nidulans , Streptomyces , Aminoácidos/metabolismo , Antibacterianos/farmacologia , Antifúngicos/metabolismo , Aspergillus nidulans/genética , Aspergillus nidulans/metabolismo , Cromatina/metabolismo , Eletrólitos , Guanidinas , Macrolídeos/metabolismo , Família Multigênica , Resorcinóis , Metabolismo Secundário/genética , Streptomyces/genética , Streptomyces/metabolismo
6.
Mycotoxin Res ; 38(2): 117-136, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35347677

RESUMO

Fungi and mycotoxins in silage can have detrimental consequences for both cattle and human health. This pilot study identified, via the routinary direct plating method, the dominant cultivable fungi in mouldy grass silages (GS) (n = 19) and maize silages (MS) (n = 28) from Austria. The profiles of regulated, modified, and emerging mycotoxins together with other fungal metabolites were analysed via LC-(ESI)MS/MS. Penicillium roqueforti, Saccharomyces spp., Geotrichum candidum, Aspergillus fumigatus and Monascus ruber were the most frequent fungal organisms identified. Other species including Mucor circinelloides, Fusarium spp. and Paecilomyces niveus were detected at lower frequencies. The presence of complex mixtures of toxic and potentially toxic compounds was evidenced by high levels and occurrences (≥ 50%) of Penicillium-produced compounds such as mycophenolic acid (MPA), roquefortines (ROCs), andrastins (ANDs) and marcfortine A. Mouldy silages contained toxins commonly produced by genus Fusarium (e.g. zearalenone (ZEN) and trichothecenes), Alternaria (like tenuazonic acid (TeA) and alternariol (AHO)) and Aspergillus (such as sterigmatocystin (STC)). Compared to those in GS, mouldy spots in MS presented significantly higher fungal counts and more diverse toxin profiles, in addition to superior levels of Fusarium spp., Penicillium spp. and total fungal metabolites. Generally, no correlation between mould counts and corresponding metabolites was detected, except for the counts of P. roqueforti, which were positively correlated with Penicillium spp. metabolites in mouldy MS. This study represents a first assessment of the fungal diversity in mouldy silage in Austria and highlights its potential role as a substantial contributor to contamination with complex mycotoxin mixtures in cattle diets.


Assuntos
Fusarium , Micotoxinas , Alternaria/metabolismo , Animais , Áustria , Bovinos , Contaminação de Alimentos/análise , Fusarium/metabolismo , Micotoxinas/análise , Projetos Piloto , Poaceae , Silagem/análise , Espectrometria de Massas em Tandem , Zea mays/microbiologia
7.
Molecules ; 26(21)2021 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-34770997

RESUMO

In the process of screening for new bioactive microbial metabolites we found a novel Æ´-pyrone derivative for which we propose the trivial name luteapyrone, in a recently described microscopic filamentous fungus, Metapochonia lutea BiMM-F96/DF4. The compound was isolated from the culture extract of the fungus grown on modified yeast extract sucrose medium by means of flash chromatography followed by preparative HPLC. The chemical structure was elucidated by NMR and LC-MS. The new compound was found to be non-cytotoxic against three mammalian cell lines (HEK 263, KB-3.1 and Caco-2). Similarly, no antimicrobial activity was observed in tested microorganisms (gram positive and negative bacteria, yeast and fungi).


Assuntos
Fungos/química , Hypocreales/química , Estrutura Molecular
8.
J Fungi (Basel) ; 7(7)2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34356936

RESUMO

Two new species, Penicillium krskae (isolated from the air as a lab contaminant in Tulln (Austria, EU)) and Penicillium silybi (isolated as an endophyte from asymptomatic milk thistle (Silybum marianum) stems from Josephine County (Oregon, USA)) are described. The new taxa are well supported by phenotypic (especially conidial ornamentation under SEM, production of red exudate and red pigments), physiological (growth at 37 °C, response to cycloheximide and CREA), chemotaxonomic (production of specific extrolites), and multilocus phylogenetic analysis using RNA-polymerase II second largest subunit (RPB2), partial tubulin (benA), and calmodulin (CaM). Both new taxa are resolved within the section Exilicaulis in series Restricta and show phylogenetic affiliation to P. restrictum sensu stricto. They produce a large spectrum of toxic anthraquinoid pigments, namely, monomeric anthraquinones related to emodic and chloremodic acids and other interesting bioactive extrolites (i.e., endocrocin, paxilline, pestalotin, and 7-hydroxypestalotin). Of note, two bianthraquinones (i.e., skyrin and oxyskyrin) were detected in a culture extract of P. silybi. Two new chloroemodic acid derivatives (2-chloro-isorhodoptilometrin and 2-chloro-desmethyldermoquinone) isolated from the exudate of P. krskae ex-type culture were analyzed by nuclear magnetic resonance (NMR) and liquid chromatography-mass spectrometry (LC-MS).

9.
IMA Fungus ; 12(1): 17, 2021 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-34233753

RESUMO

Four new Keratinophyton species (Ascomycota, Pezizomycotina, Onygenales), K. gollerae, K. lemmensii, K. straussii, and K. wagneri, isolated from soil samples originating from Europe (Austria, Italy, and Slovakia) are described and illustrated. The new taxa are well supported by phylogenetic analysis of the internal transcribed spacer region (ITS) region, the combined data analysis of ITS and the nuclear large subunit (LSU) rDNA, and their phenotype. Based on ITS phylogeny, within the Keratinophyton clade, K. lemmensii is clustered with K. durum, K. hubeiense, K. submersum, and K. siglerae, while K. gollerae, K. straussii and K. wagneri are resolved in a separate terminal cluster. All four new species can be well distinguished from other species in the genus based on phenotype characteristics alone. Ten new combinations are proposed for Chrysosporium species which are resolved in the monophyletic Keratinophyton clade. A new key to the recognized species is provided herein.

10.
Int J Microbiol ; 2019: 6253829, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31662760

RESUMO

A new species, Saksenaea dorisiae (Mucoromycotina, Mucorales), isolated from a water sample originating from a private well in Manastirica, Petrovac, in the Republic of Serbia (Europe), is described and illustrated. The new taxon is well supported by multilocus phylogenetic analysis that included the internal transcribed spacer (ITS) region, domains D1 and D2 of the 28S rRNA gene (LSU), and translation elongation factor-1α gene (tef-1α), and it is resolved in a clade with S. oblongispora and S. trapezispora. This fungus is characterized by its moderately slow growth at 15 and 37°C, sparse rhizoids, conical-shaped sporangia, and short-cylindrical sporangiospores. Saksenaea dorisiae is a member of the opportunistic pathogenic genus often involved in severe human and animal mucormycoses encountered in tropical and subtropical regions. Despite its sensitivity to several conventional antifungals (terbinafine and ciclopirox), the fungus can potentially evoke clinically challenging infections. This is the first novel taxon of the genus Saksenaea described from the moderately continental climate area of Europe.

11.
Mycotoxin Res ; 30(4): 213-20, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25109845

RESUMO

The secondary metabolite profiles of microfungi of the genus Penicillium isolated from samples of grape berries collected in two different phases during two vegetative seasons in Slovakia is described to assess the taxonomy. Three Slovak vine regions have been selected for this study, based on their climatic differences and national economic importance. Cultures of microfungi isolated from berries were incubated on different selective media for macro and micromorphology identification. The species Penicillium brevicompactum, Penicillium crustosum, Penicillium chrysogenum, Penicillium expansum, Penicillium palitans and Penicillium polonicum were identified according to growth and morphology. The related strains were found to produce a broad spectrum of fungal metabolites, including roquefortine C, chaetoglobosin A, penitrem A, cyclopeptin, cyclopenin, viridicatin, methylviridicatin, verrucofortine, secalonic acid D, cyclopiazonic acid, fumigaclavine and mycophenolic acid. Chemotaxonomy was performed using high-performance liquid chromatography (HPLC) and mass spectrometry (MS). Dried grape berries were also analyzed allowing to assess the presence of patulin, roquefortine C and penicillic acid; this last one has been identified in dried berries but not in vitro.


Assuntos
Produtos Biológicos/análise , Frutas/microbiologia , Penicillium/química , Penicillium/classificação , Vitis/microbiologia , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas , Penicillium/crescimento & desenvolvimento , Penicillium/isolamento & purificação , Eslováquia
12.
BMC Microbiol ; 13: 165, 2013 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-23865912

RESUMO

BACKGROUND: HC-toxin, a cyclic tetrapeptide, is a virulence determinant for the plant pathogenic fungus Cochliobolus carbonum. It was recently discovered that another fungus, Alternaria jesenskae, also produces HC-toxin. RESULTS: The major genes (collectively known as AjTOX2) involved in the biosynthesis of HC-toxin were identified from A. jesenskae by genomic sequencing. The encoded orthologous proteins share 75-85% amino acid identity, and the genes for HC-toxin biosynthesis are duplicated in both fungi. The genomic organization of the genes in the two fungi show a similar but not identical partial clustering arrangement. A set of representative housekeeping proteins show a similar high level of amino acid identity between C. carbonum and A. jesenskae, which is consistent with the close relatedness of these two genera within the family Pleosporaceae (Dothideomycetes). CONCLUSIONS: This is the first report that the plant virulence factor HC-toxin is made by an organism other than C. carbonum. The genes may have moved by horizontal transfer between the two species, but it cannot be excluded that they were present in a common ancestor and lost from other species of Alternaria and Cochliobolus.


Assuntos
Alternaria/genética , Vias Biossintéticas/genética , Peptídeos Cíclicos/biossíntese , DNA Fúngico/química , DNA Fúngico/genética , Proteínas Fúngicas/genética , Duplicação Gênica , Ordem dos Genes , Genes Fúngicos , Dados de Sequência Molecular , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Fatores de Virulência/biossíntese
13.
Mycopathologia ; 174(3): 239-45, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22539211

RESUMO

A total of 939 isolates of 11 genera representing 15 species of keratinophilic fungi were isolated and identified from the soils of three long-term fold-grazed pastures in national parks of Slovakia (Pod Ploskou, Strungový príslop, and Pod Keckou) and one non-fold-grazed pasture in sierra Stolicke vrchy (Diel) using the hair-baiting technique. Keratinophilic fungi were present in all soil samples with a prevalence of Trichophyton ajelloi and Paecilomyces lilacinus. These fungi were more abundant in soil from fold-grazed pasture (Strungový príslop) compared to non-fold-grazed pasture (Diel). The occurrence of the other keratinophilic fungi was substantially lower, likely because of low pH in some soils.


Assuntos
Biodiversidade , Fungos/isolamento & purificação , Fungos/metabolismo , Queratinas/metabolismo , Microbiologia do Solo , Fungos/classificação , Fungos/crescimento & desenvolvimento , Cabelo/microbiologia , Eslováquia
14.
J Environ Sci Health B ; 46(3): 213-9, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21442537

RESUMO

The aim of this in vitro study was to examine the secretion activity, markers of proliferation and apoptosis in porcine ovarian granulosa cells (GCs) after deoxynivalenol (DON) addition. Ovarian granulosa cells were incubated with DON for 24h: 10, 100 and 1000 ng/mL, while the control group received no DON. The secretion of insulin-like growth factor I (IGF-I) and progesterone was determined by radioimmunoassay (RIA) and expression of cyclin B1, PCNA and caspase-3 by immunocytochemistry. IGF-I release by GCs was inhibited by DON, while progesterone release and the expression of cyclin B1 was stimulated by DON (at 1000 ng/mL but not at 10 and 100 ng/mL). PCNA expression was stimulated by DON (at 100 and 1000 ng/mL but not at 10 ng/mL). Caspase-3 expression was not influenced by DON treatment (at all doses). In conclusion, our results indicate, (1) a direct effect of DON on secretion of growth factor IGF-I and steroid hormone progesterone, (2) expression of markers of proliferation (cyclin B1 and PCNA) but not on the (3) expression of marker of apoptosis (caspase-3) in porcine ovarian granulosa cells. This in vitro study suggests the dose-dependent association of DON on porcine ovarian functions.


Assuntos
Células da Granulosa/efeitos dos fármacos , Tricotecenos/toxicidade , Animais , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Ciclina B1/metabolismo , Relação Dose-Resposta a Droga , Feminino , Células da Granulosa/metabolismo , Imuno-Histoquímica , Fator de Crescimento Insulin-Like I/metabolismo , Progesterona/metabolismo , Suínos , Fatores de Tempo , Tricotecenos/química
15.
J Ind Microbiol Biotechnol ; 38(9): 1329-35, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21132348

RESUMO

Tolypocladium inflatum is known primarily for its production of the cyclosporines that are used as an immunosuppressive drug. However, we report here the production of the carcinogenic fumonisins B(2) and B(4) by this biotechnologically relevant fungal genus. These mycotoxins were detected in 11 strains tested from three species: Tolypocladium inflatum, T. cylindrosporum, and T. geodes. Production of fumonisins by Fusarium spp. and Aspergillus niger is highly medium- and temperature-dependent, so the effect of these parameters on fumonisin production by three T. inflatum strains was studied. Maximum production was achieved on media with high sugar content incubated at 25-30°C. Since these results demonstrate that fumonisin production could be widespread within the genus Tolypocladium, the potential contamination of commercial cyclosporine preparations with fumonisins needs to be investigated.


Assuntos
Fumonisinas/metabolismo , Hypocreales/metabolismo , Micotoxinas/biossíntese , Aspergillus niger/metabolismo , Fumonisinas/química , Micotoxinas/química , Temperatura
16.
Anal Bioanal Chem ; 395(5): 1355-72, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19669641

RESUMO

This paper describes the application of a previously published multi-mycotoxin method for food and feed matrices based on liquid chromatography/electrospray ionization-tandem mass spectrometry (HPLC/ESI-MS/MS) to the analysis of microbial metabolites in indoor matrices. The range of investigated analytes has been extended by 99 fungal and bacterial metabolites to cover now 186 compounds overall. The method is based on a single extraction step using an acidified acetonitrile/water mixture (which has been determined to be preferable to methanol and ethyl acetate) followed by analysis of the diluted crude extract. The analytical signal of one third of the investigated analytes was reduced by more than 50% due to matrix effects in a spiked extract of house dust, whereas the other investigated materials were less critical in that aspect. For determination of method performance characteristics, a spiked reference material for house dust was chosen as a model sample for an extremely complex matrix. With few exceptions, coefficients of variation of the whole procedure of <10% and limits of detection of <50 microg kg(-1) were obtained. The apparent recoveries were below 50% for half of the investigated analytes due to incomplete extraction and/or detection-related matrix effects. The application of the method to 14 samples from damp buildings revealed the presence of 20 different analytes at concentrations of up to 130 mg kg(-1). Most of these compounds have never been identified before in real-world samples, although they are known to be produced by indoor-relevant fungi. This underlines the great value of the described method for the on-site determination of microbial metabolites.


Assuntos
Bactérias/química , Cromatografia Líquida de Alta Pressão/métodos , Poeira/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos , Bactérias/metabolismo
17.
Ann Agric Environ Med ; 16(2): 325-31, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20047270

RESUMO

To survey the overall fungal contamination and toxicological potential of isolated fungi, a mycological investigation of 56 samples of wheat bran was carried out during March-June 2004 in Slovakia. Despite of low values of water activity found in the samples reaching an average of 0.54, the individual samples were contaminated with fungi in a range from 1.82 x 10(1) - 3.42 x 10(4) colonies forming units per gram of sample (CFU/g). A total number of 65 fungal species pertaining to 23 genera were recovered. The most dominant and diverse genus was Penicillium (20 spp.) followed by Aspergillus (10 spp.) and Cladosporium (3 spp.) with 100 percentages, 89 percentages and 72 percentages frequency, respectively. Isolates of potentially toxinogenic species recovered from the samples were found to produce various mycotoxins, namely citrinin (23 isolates), cyclopiazonic acid (43 isolates), griseofulvin (23 isolates), ochratoxin A (14 isolates), patulin (30 isolates), penitrem A (18 isolates) and sterigmatocystin (7 isolates). Furthermore, fumonisin B1 as well as moniliformin producing Fusarium strains, were recovered. It is evident that this type of cereal commodity is a significant source of toxicologically relevant species of which majority are true toxinogenic.


Assuntos
Fibras na Dieta/microbiologia , Fungos/isolamento & purificação , Micotoxinas/análise , Contagem de Colônia Microbiana , Fungos/patogenicidade
18.
Microbiol Res ; 163(2): 208-14, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-16793249

RESUMO

Alternaria jesenskae sp. nov. recovered from seeds of a shrubby perennial plant Fumana procumbens (Cistaceae) in Slovakia is described and illustrated. The new taxon can be clearly separated from the other related large-spored and filament-beaked Alternaria species based on sequences of the ITS1, 5.8S and ITS2 region as well as by its distinctive morphology. Even though the molecular data have shown close relatedness with A. multirostrata, the new species is morphologically most similar to A. tomatophila distinguished primarily by the pronounced colony pigmentation, conidial septation and beak branching.


Assuntos
Alternaria/isolamento & purificação , Cistaceae/microbiologia , Alternaria/classificação , Alternaria/citologia , Alternaria/genética , DNA Fúngico/genética , DNA Ribossômico/genética , DNA Espaçador Ribossômico/genética , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 18S/genética , RNA Ribossômico 5,8S/genética , Sementes/microbiologia , Eslováquia
19.
Ann Agric Environ Med ; 13(2): 193-200, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17195991

RESUMO

To contribute towards the knowledge of microbiology of feeds, more than 100 samples of poultry feed mixtures from Slovakia were mycologically investigated in terms of the overall fungal diversity and toxicological potential of isolated fungi. The study revealed that out of 22 genera recovered, Penicillium was the most frequent and diverse genus, followed by Aspergillus and Mucor being found in 89 % (34 spp.), 69 % (11 spp.) and 50 % (4 spp.), respectively. The most frequently encountered taxa were Fusarium proliferatum, followed by Penicillium aurantiogriseum, Mucor racemosus, Penicillium crustosum and Aspergillus flavus . In addition, the following genera were recorded (in descending order) Rhizopus (44 %, 3 spp.), Eurotium (42 %, 5 spp.), Fusarium (42 %, 3 spp.), Cladosporium (31 %, 1 sp.), Alternaria (22 %, 3 spp.), Absidia (16 %, 3 spp.), Acremonium (12 %, 2 spp.), Scopulariopsis (10 %, 2 spp.), Paecilomyces (4 %, 1 sp.), Ulocladium (3 %, 1 sp.), Trichoderma (2 %, 1 sp.), Zygorrhynchus (2 %, 1 sp.), and finally Emericella, Epicoccum, Geosmithia, Monascus, Stachybotrys, Syncephalastrum and Wardomyces , all were encountered in 1 % of the samples being represented by a single species. The mean value counts of total fungi ranged from 1 x 10 (3) to 200 x 10(5) cfu/g. Outcomes from mycotoxin screening within the appropriate potentially toxinogenic species showed a number of mycotoxin producers, namely those forming aflatoxin B (1) (n=3), citrinin (17), cyclopiazonic acid (76), fumonisin B(1) (86), griseofulvin (42), moniliformin (18), ochratoxin A (5), patulin (56), penitrem A (30) and sterigmatocystin (10).


Assuntos
Ração Animal/microbiologia , Fungos/isolamento & purificação , Fungos/efeitos da radiação , Aves Domésticas , Sementes/microbiologia , Ração Animal/análise , Ração Animal/toxicidade , Animais , Aspergillus flavus/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Microbiologia de Alimentos , Fusarium/isolamento & purificação , Mucor/isolamento & purificação , Micoses/microbiologia , Micoses/veterinária , Penicillium/isolamento & purificação , Sementes/toxicidade , Eslováquia
20.
Int J Food Microbiol ; 105(1): 19-25, 2005 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-16046021

RESUMO

A total of 50 samples of poultry feed mixtures of Slovakian origin were analyzed for eight toxicologically significant Fusarium mycotoxins, namely zearalenone (ZON), A-trichothecenes: diacetoxyscirpenol (DAS), T-2 toxin (T-2) and HT-2 toxin (HT-2) and B-trichothecenes: deoxynivalenol (DON), 3-acetyl-deoxynivalenol (3-ADON), 15-acetyl-deoxynivalenol (15-ADON) and nivalenol (NIV). The A-trichothecenes and the B-trichothecenes were detected by means of high pressure liquid chromatography with tandem mass spectrometry detection (HPLC-MS/MS) and gas chromatography electron capture detection (GC-ECD), respectively. Reversed phase-high performance liquid chromatography with a fluorescence detector (RP-HPLC-FLD) was used for ZON detection. The most frequent mycotoxin detected was T-2, which was found in 45 samples (90%) in relatively low concentrations ranging from 1 to 130 microg kg(-1) (average 13 microg kg(-1)), followed by ZON that was found in 44 samples (88%) in concentrations ranging from 3 to 86 microg kg(-1) (average 21 microg kg(-1)). HT-2 and DON were detected in 38 (76%) and 28 (56%) samples, respectively, in concentrations of 2 to 173 (average 18 microg kg(-1)) for HT-2 and 64 to 1230 microg kg(-1) sample (average 303 microg kg(-1)) for DON. The acetyl-derivatives of DON were in just four samples, while NIV was not detected in any of the samples investigated. In as many as 22 samples (44%), a combination of four simultaneously co-occurring mycotoxins, i.e. T-2, HT-2, ZON and DON, was revealed. Despite the limited number of samples investigated during this study poultry feed mixtures may represent a risk from a toxicological point of view and should be regarded as a potential source of the Fusarium mycotoxins in Central Europe. This is the first reported study dealing with zearalenone and trichothecene contamination of poultry mixed feeds from Slovakia.


Assuntos
Ração Animal/análise , Contaminação de Alimentos/análise , Tricotecenos/isolamento & purificação , Zearalenona/isolamento & purificação , Animais , Cromatografia Líquida de Alta Pressão/métodos , Análise de Alimentos , Microbiologia de Alimentos , Incidência , Espectrometria de Massas/métodos , Aves Domésticas , Eslováquia , Tricotecenos/análise , Zearalenona/análise
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