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1.
Microb Ecol ; 85(4): 1215-1225, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-35415771

RESUMO

Anthropogenic change at a global scale is affecting life on Earth with impacts on freshwaters. Aquatic hyphomycetes are fungi that drive organic matter decomposition in freshwaters and mediate energy transfer to higher trophic levels. Intraspecific trait variability affects ecological processes and can account for species adaptations to environmental change. To ascertain how aquatic hyphomycetes respond to global change related stressors, we selected 20 strains (7 species), based on their co-occurrence in streams and phylogenetic relatedness. We measured fungal growth rates at different temperatures (7 levels), nutrient concentrations (6 levels) and medium moisture (6 levels). Our results indicate that all stressors affected fungal growth, and responses to nutrient enrichment and moisture were strain specific. Fungal responses to the stressors were not explained by their phylogenetic relatedness. In the absence of stressors, interspecific diversity best explained the variance in fungal traits, while the increase in the stress gradient increased the importance of intraspecific diversity.


Assuntos
Fungos Mitospóricos , Filogenia , Fungos Mitospóricos/fisiologia , Rios/microbiologia , Água Doce , Fenótipo , Folhas de Planta/microbiologia , Fungos/genética , Ecossistema
2.
Int J Mol Sci ; 21(12)2020 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-32545883

RESUMO

We present a case study report into nutritional competition between Trichoderma spp. isolated from wild raspberries and fungal phytopathogenic isolates (Colletotrichum sp., Botrytis sp., Verticillium sp. and Phytophthora sp.), which infect soft fruit ecological plantations. The competition was evaluated on the basis of nutritional potentiates. Namely, these were consumption and growth, calculated on the basis of substrate utilization located on Biolog® Filamentous Fungi (FF) plates. The niche size, total niche overlap and Trichoderma spp. competitiveness indices along with the occurrence of a stressful metabolic situation towards substrates highlighted the unfolding step-by-step approach. Therefore, the Trichoderma spp. and pathogen niche characteristics were provided. As a result, the substrates in the presence of which Trichoderma spp. nutritionally outcompete pathogens were denoted. These were adonitol, D-arabitol, i-erythritol, glycerol, D-mannitol and D-sorbitol. These substrates may serve as additives in biopreparations of Trichoderma spp. dedicated to plantations contaminated by phytopathogens of the genera Colletotrichum sp., Botrytis sp., Verticillium sp. and Phytophthora sp.


Assuntos
Fungos Mitospóricos/fisiologia , Phytophthora/crescimento & desenvolvimento , Rubus/crescimento & desenvolvimento , Trichoderma/fisiologia , Botrytis/crescimento & desenvolvimento , Colletotrichum/crescimento & desenvolvimento , Eritritol/análise , Frutas/crescimento & desenvolvimento , Frutas/microbiologia , Glicerol/análise , Manitol/análise , Ribitol/análise , Rubus/microbiologia , Saccharomycetales/crescimento & desenvolvimento , Microbiologia do Solo , Sorbitol/análise , Álcoois Açúcares/análise
3.
An Acad Bras Cienc ; 91(3): e20180545, 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31365651

RESUMO

Fungi play an important role in litter decomposition in forest ecosystems and are considered an undersampled group in the Amazon biome. This study aims to describe the composition, richness and frequency of species of conidial fungi associated with palm trees in an area of ​​the Amapá National Forest, State of Amapá, Brazil. Palm leaf litter was collected from July 2009 to June 2010, incubated in moist chambers and examined for the presence of fungi. One hundred and seven species of conidial fungi were identified, in 79 genera and 25 families. As for the relative frequency of the species, the majority (94.4%) was sporadic and occurred on leaflets. We report new records for South America (Chaetopsis intermedia, Chaetochalara laevis and Thysanophora verrucosa) and Brazil (Chloridium phaeosporum, Helminthosporiella stilbacea and Zygosporium geminatum), and 83 for the State of Amapá, while 15 are also new for the Brazilian Amazon. This study significantly increases the knowledge about the distribution of the fungal species in the Amazon biome, and emphasizes the importance of the conservation of these organisms particularly in view of the large number of sporadic species recorded.


Assuntos
Arecaceae/microbiologia , Biodiversidade , Fungos Mitospóricos/fisiologia , Esporos Fúngicos/fisiologia , Brasil , Estações do Ano
4.
Microb Ecol ; 76(2): 328-339, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29417187

RESUMO

Aquatic hyphomycetes represent a large component of the microbial assemblage that decomposes submerged leaf-litter in fluvial ecosystems. The structure and activity of these fungal decomposers depend on environmental factors. Fungal communities may adapt to local habitat conditions; however, little is known about how fungal communities respond to abrupt changes in factors such as nutrient availability and temperature. To respond to this question, we carried out a cross-transplantation experiment, which assessed the decomposer activity and structure of this microbial community on decaying leaves transplanted from a cold and oligotrophic stream (S1) to a warmer and nitrogen-richer one (S2) and vice versa. Results were compared to those from untransplanted leaves decomposing either at S1 or at S2. In terms of days, untransplanted leaves were decomposed at a similar rate in both streams; the change to warmer and nitrogen-richer waters (S1 ➔ S2) significantly enhanced the decomposition process while the reciprocal transplantation (S2 ➔ S1) did not alter decomposition rate. However, when standardizing the temperature effects by using degree-days, microbial decomposers under colder conditions were more efficient in terms of accumulated heat, independent of the initial or final incubation site. Regarding community structure, taxa richness and diversity of aquatic hyphomycetes appear to be favoured under warmer and richer conditions, increasing after transplantation to S2 but with little effect on the predominant taxa. However, the reciprocal transplantation (S2 ➔ S1) yielded a clear decline of the dominant taxa at S2 (Lunulospora curvula) in favour of the local dominant ones. Thus, effects of environmental changes on activity and community structure can be highly variable and not always clearly linked or reciprocal. Therefore, results from simplified experimental designs (e.g. artificial assemblages under laboratory conditions) must be taken with caution. Additional field studies and manipulative experimentation dealing with natural communities are required when trying to extend individual results to complex scenarios such as those projected by global change.


Assuntos
Fungos Mitospóricos/fisiologia , Nutrientes , Rios/microbiologia , Temperatura , Oceano Atlântico , Biodiversidade , Canadá , Ecossistema , Microbiologia Ambiental , Microbiota , Fungos Mitospóricos/classificação , Micobioma , Nitrogênio , Folhas de Planta/microbiologia , Rios/química
5.
Artigo em Inglês | MEDLINE | ID: mdl-28643953

RESUMO

In this study, we investigated the effect of the entomopathogenic fungus Nomuraea rileyi on Helicoverpa armigera cellular immune responses. Nomuraea rileyi infection had no effect on total hemocyte count (THC), but impaired hemocyte-mediated phagocytosis, nodulation, and encapsulation responses. Nomuraea rileyi infection led to a significant reduction in hemocyte spreading. An in vitro assay revealed that plasma from N. rileyi infected H. armigera larvae suppressed the spreading ability of hemocytes from naïve larvae. We infer that N. rileyi suppresses the cellular immune response of its host, possibly by secreting exogenous, cytotoxic compounds into the host's hemolymph.


Assuntos
Interações Hospedeiro-Patógeno , Imunidade Celular , Fungos Mitospóricos/fisiologia , Mariposas/imunologia , Animais , Mariposas/microbiologia
6.
Orig Life Evol Biosph ; 46(4): 403-418, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27106019

RESUMO

In this study we investigated the security of a spaceflight experiment from two points of view: spreading of dried fungal spores placed on the different wafers and their viability during short and long term missions on the International Space Station (ISS). Microscopic characteristics of spores from dried spores samples were investigated, as well as the morphology of the colonies obtained from spores that survived during mission. The selected fungal species were: Aspergillus niger, Cladosporium herbarum, Ulocladium chartarum, and Basipetospora halophila. They have been chosen mainly based on their involvement in the biodeterioration of different substrate in the ISS as well as their presence as possible contaminants of the ISS. From biological point of view, three of the selected species are black fungi, with high melanin content and therefore highly resistant to space radiation. The visual inspection and analysis of the images taken before and after the short and the long term experiments have shown that all biocontainers were returned to Earth without damages. Microscope images of the lids of the culture plates revealed that the spores of all species were actually not detached from the surface of the wafers and did not contaminate the lids. From the adhesion point of view all types of wafers can be used in space experiments, with a special comment on the viability in the particular case of iron wafers when used for spores that belong to B. halophila (halophilic strain). This is encouraging in performing experiments with fungi without risking contamination. The spore viability was lower in the experiment for long time to ISS conditions than that of the short experiment. From the observations, it is suggested that the environment of the enclosed biocontainer, as well as the species'specific behaviour have an important effect, reducing the viability in time. Even the spores were not detached from the surface of the wafers, it was observed that spores used in the long term experiment lost the outer layer of their coat without affecting the viability since they were still protected by the middle and the inner layer of the coating. This research highlights a new protocol to perform spaceflight experiments inside the ISS with fungal spores in microgravity conditions, under the additional effect of possible cosmic radiation. According to this protocol the results are expressed in terms of viability, microscopic and morphological changes.


Assuntos
Radiação Cósmica/efeitos adversos , Fungos Mitospóricos/fisiologia , Voo Espacial , Esporos Fúngicos/fisiologia , Ausência de Peso/efeitos adversos , Viabilidade Microbiana/efeitos da radiação , Fungos Mitospóricos/efeitos da radiação , Astronave , Esporos Fúngicos/efeitos da radiação
7.
Gig Sanit ; 95(10): 293-9, 2016.
Artigo em Russo | MEDLINE | ID: mdl-29431333

RESUMO

The composition and the structure of microbial communities in areas of Arctic settlements were studied. The main attention has been given to microscopic fungi. As result of observation of 5 Arctic regions 117 species of microscopic fungi are revealed in soils and anthropogenic substrates. The identification was carried out with the use ofmycological and molecular genetic methods. Most ofspecies belong to the Ascomycotina. Genus Penicillium is characterized by the most species diversity (24 species). Most offungi are destructors of various materials and potential human pathogens. Dominant species are revealed. The distribution of microorganisms in the living and working areas of polar stations, as well as the adjacent areas are described. Black-colored fungi adapted to unfavorable environment are often the dominated group of microorganisms on soils and anthropogenic substrates. The shaping of soil microbiota was shown to be related to the anthropogenic impact. Considerable similarity of microbial communities composition in the soil and man-made substrates is fixed. As result of mycological analysis of contaminated soils 76 species of microscopic fungi were observed, but 41 species of them (53.9%) were identified in the areas of Arctic polar stations on the man-made materials. These species include the representatives of the genera Alternaria, Aspergillus, Aureobasidium, Chaetomium, Cladosporium, Exophiala, Geomyces, Humicola, Penicillium, Mucor, Phoma, Rhodotorula, Trichoderma and Ulocladium. The obtained data show a significant similarity in species composition of contaminated soils and anthropogenic substrates. Human activity contributes to the distribution of cosmopolitan species, including opportunistic fungi, in the Arctic region. The high numbers of organotrophic bacteria were revealed in soil samples. Some species of microorganisms produce the organic acids in an external environment that promotes the erosion of materials.


Assuntos
Fungos Mitospóricos , Microbiologia do Solo , Solo/normas , Regiões Árticas/epidemiologia , Biota , Monitoramento Ambiental/métodos , Monitoramento Ambiental/estatística & dados numéricos , Humanos , Microbiota , Fungos Mitospóricos/classificação , Fungos Mitospóricos/isolamento & purificação , Fungos Mitospóricos/fisiologia , Filogeografia , Federação Russa/epidemiologia
8.
Phytopathology ; 105(12): 1568-72, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26555672

RESUMO

Blast, caused by Pyricularia oryzae, is one of the major diseases of wheat in South America. We identified a new gene for resistance to Triticum isolates of P. oryzae in common wheat 'S-615', and designated it "resistance to Magnaporthe grisea 8" (Rmg8). Rmg8 was assigned to chromosome 2B through molecular mapping with simple-sequence repeat markers. To identify an avirulence gene corresponding to Rmg8, Triticum isolate Br48 (avirulent on S-615) was crossed with 200R29 (virulent on S-615), an F1 progeny derived from a cross between an Eleusine isolate (MZ5-1-6) and Br48. Segregation analysis of their progeny revealed that avirulence of Br48 on S-615 was conditioned by a single gene, which was designated AVR-Rmg8. AVR-Rmg8 was closely linked to AVR-Rmg7, which corresponded to Rmg7 located on chromosome 2A of tetraploid wheat.


Assuntos
Interações Hospedeiro-Patógeno/genética , Fungos Mitospóricos/fisiologia , Triticum/genética , Mapeamento Cromossômico , Cromossomos de Plantas , Genes de Plantas , Imunidade Vegetal/genética , Poliploidia , Triticum/imunologia
9.
Mycoses ; 58(5): 267-72, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25728464

RESUMO

Chromoblastomycosis is a chronic granulomatous disease caused frequently by fungi of the Fonsecaea genus. The objective of this study was the phenotypic and molecular identification of F. pedrosoi strains isolated from chromoblastomycosis patients in Mexico and Venezuela. Ten strains were included in this study. For phenotypic identification, we used macroscopic and microscopic morphologies, carbohydrate assimilation test, urea hydrolysis, cixcloheximide tolerance, proteolitic activity and the thermotolerance test. The antifungal activity of five drugs was evaluated against the isolates. Molecular identification was performed by sequencing the internal transcribed spacer (ITS) ribosomal DNA regions of the isolated strains. The physiological analysis and morphological features were variable and the precise identification was not possible. All isolates were susceptible to itraconazole, terbinafine, voriconazole and posaconazole. Amphotericin B was the least effective drug. The alignment of the 559-nucleotide ITS sequences from our strains compared with sequences of GenBank revealed high homology with F. pedrosoi (EU285266.1). In this study, all patients were from rural areas, six from Mexico and four from Venezuela. Ten isolates were identified by phenotypic and molecular analysis, using ITS sequence and demonstrated that nine isolates from Mexico and Venezuela were 100% homologous and one isolate showed a small genetic distance.


Assuntos
Ascomicetos/isolamento & purificação , Cromoblastomicose/microbiologia , Fungos Mitospóricos/isolamento & purificação , Pele/microbiologia , Adulto , Idoso , Anfotericina B/farmacologia , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Ascomicetos/classificação , Ascomicetos/genética , Ascomicetos/fisiologia , Cromoblastomicose/tratamento farmacológico , DNA Espaçador Ribossômico/genética , Feminino , Humanos , Itraconazol/farmacologia , Masculino , México , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Fungos Mitospóricos/classificação , Fungos Mitospóricos/genética , Fungos Mitospóricos/fisiologia , Dados de Sequência Molecular , Fenótipo , Análise de Sequência de DNA , Venezuela , Voriconazol/farmacologia
10.
Commun Agric Appl Biol Sci ; 80(2): 205-11, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-27145587

RESUMO

In this study, biological activity of entomopathogenic fungi (4 strains) isolated from the Colorado potato beetle and the commercial biopesticides containing entomopathogenic fungi; Priority® (Paecilomyces fumosoroseus), Nibortem® (Verticillium lecanii), Nostalgist® (Beauveria bassiana), Bio-Magic* (Metarhizium anisopliae), Bio-Nematon* (Paeciliomyces sp.) and plant extracts; Nimbedicine EC* (Azadiractin) were determined against Leptinotarsa decemlineata under laboratory conditions. An Imidacloprid active ingredient commercial insecticide was also used to compare the insecticidal activity and distilled water was used as control. The biological control agents were applied to 2nd-3rd larval instars, 4th larval instars and adults with spray and leaf dipping methods. Single concentration (108 conidia/mL⁻¹) of entomopathogenic fungi and recommended dose of bioinsecticides were prepared for application. The number of dead insects were determined at 3, 5, and 7 days after applications. Experiments were conducted at 25 ±1° C and 60% ± 5 relative humidity with 16:8 h light: dark conditions. Entomopathogenic fungi and bioinsecticides were found to be more effective on larval stage than 4th larval instars and adults. In spray methods, Bio-Magic®, Nibortem®, and Nostalgist® caused 96.4%, 92.9% and 82.1% mortality on 2nd larval instars and 20%, 36.7% and 33.3% mortality on adults, respectively. All local fungal isolates (B. bassiana) applied on 2nd and 4th larval instars caused 100% mortality. Adults showed 58.6-86.2% mortality.


Assuntos
Agentes de Controle Biológico/farmacologia , Besouros/efeitos dos fármacos , Controle de Insetos , Inseticidas/farmacologia , Controle Biológico de Vetores , Animais , Besouros/crescimento & desenvolvimento , Besouros/microbiologia , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Larva/microbiologia , Limoninas/farmacologia , Fungos Mitospóricos/fisiologia , Extratos Vegetais/farmacologia , Especificidade da Espécie
11.
ScientificWorldJournal ; 2014: 250693, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24587715

RESUMO

Endophytes are microorganisms (bacteria or fungi or actinomycetes) that dwell within robust plant tissues by having a symbiotic association. They are ubiquitously associated with almost all plants studied till date. Some commonly found endophytes are those belonging to the genera Enterobacter sp., Colletotrichum sp., Phomopsis sp., Phyllosticta sp., Cladosporium sp., and so forth. Endophytic population is greatly affected by climatic conditions and location where the host plant grows. They produce a wide range of compounds useful for plants for their growth, protection to environmental conditions, and sustainability, in favour of a good dwelling place within the hosts. They protect plants from herbivory by producing certain compounds which will prevent animals from further grazing on the same plant and sometimes act as biocontrol agents. A large amount of bioactive compounds produced by them not only are useful for plants but also are of economical importance to humans. They serve as antibiotics, drugs or medicines, or the compounds of high relevance in research or as compounds useful to food industry. They are also found to have some important role in nutrient cycling, biodegradation, and bioremediation. In this review, we have tried to comprehend different roles of endophytes in plants and their significance and impacts on man and environment.


Assuntos
Mudança Climática , Ecossistema , Enterobacter/fisiologia , Fungos Mitospóricos/fisiologia , Modelos Biológicos , Plantas/microbiologia , Animais , Humanos
12.
World J Microbiol Biotechnol ; 30(5): 1639-47, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24310522

RESUMO

The use of antagonist microorganisms against fungal plant pathogens is an attractive and ecologically alternative to the use of chemical pesticides. Streptomyces are beneficial soil bacteria and potential candidates for biocontrol agents. This study reports the isolation, characterization and antagonist activity of soil streptomycetes from the Los Petenes Biosphere Reserve, a Natural protected area in Campeche, Mexico. The results showed morphological, physiological and biochemical characterization of six actinomycetes and their inhibitory activity against Curvularia sp., Aspergillus niger, Helminthosporium sp. and Fusarium sp. One isolate, identified as Streptomyces sp. CACIS-1.16CA showed the potential to inhibit additional pathogens as Alternaria sp., Phytophthora capsici, Colletotrichum sp. and Rhizoctonia sp. with percentages ranging from 47 to 90 %. This study identified a streptomycete strain with a broad antagonist activity that could be used for biocontrol of plant pathogenic fungi.


Assuntos
Actinobacteria/isolamento & purificação , Agentes de Controle Biológico , Fungos Mitospóricos/fisiologia , Phytophthora/fisiologia , Microbiologia do Solo , Streptomyces/isolamento & purificação , Sequência de Bases , DNA Bacteriano/análise , DNA Ribossômico/análise , Dados de Sequência Molecular , Filogenia , Doenças das Plantas/microbiologia , Streptomyces/classificação , Streptomyces/fisiologia
13.
Mycologia ; 105(3): 521-9, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23233506

RESUMO

The Eocene (~ 48.7 Ma, Ypresian-Lutetian) Princeton Chert of British Columbia, Canada, has long been recognized as a significant paleobotanical locality, and a diverse assemblage of anatomically preserved fossil plants has been extensively documented. Co-occurring fossil fungi also have been observed, but the full scope of their diversity has yet to be comprehensively assessed. Here, we present the first of a series of investigations of fossilized fungi associated with the silicified plants of the Princeton Chert. This report focuses on saprotrophic, facultative-aquatic hyphomycetes observed in cortical aerenchyma tissue of an enigmatic angiosperm, Eorhiza arnoldii. Our use of paleontological thin sections provides the opportunity to observe and infer developmental features, making it possible to more accurately attribute two hyphomycetes that were observed in previous studies. These comprise multiseptate, holothallic, chlamydospore-like phragmoconidia most similar to extant Xylomyces giganteus and basipetal phragmospore-like chains of amerospores like those of extant Thielaviopsis basicola. We also describe a third hyphomycete that previously has not been recognized from this locality; biseptate, chlamydosporic phragmoconidia are distinguished by darkly melanized, inflated apical cells and are morphologically similar to Brachysporiella rhizoidea or Culcitalna achraspora.


Assuntos
Fósseis , Magnoliopsida/microbiologia , Fungos Mitospóricos/isolamento & purificação , Fungos Mitospóricos/fisiologia , Fungos Mitospóricos/genética , Fungos Mitospóricos/ultraestrutura , Paleontologia
14.
Wei Sheng Wu Xue Bao ; 53(9): 957-65, 2013 Sep 04.
Artigo em Zh | MEDLINE | ID: mdl-24377248

RESUMO

OBJECTIVE: We isolated Pseudomonas strains from soil samples collected from Changsha, Hunan province, catalogued them and studied the antimicrobial and antitumor activity. METHODS: We isolated Pseudomonas strains from soil samples through Galleria bait method, identified and catalogued the isolated strains according to morphological observation, physiological and biochemical characteristics and the homologous analysis of 16S rRNA sequences of nucleotides. Antimicrobial, antagonistic fungi and anti-tumor activities were studied by diffusion plate assay, dual-culture assay and cytotoxicity test respectively. RESULTS: We isolated 5 Pseudomonas strains from vegetable field and forest land of Changsha suburb, catalogued and named them as Pseudomonas protegens CY01, Pseudomonas chlororaphis CY02, Pseudomonas oryzihabitans CY04, Pseudomonas sp. CY05 and Pseudomonas putida CY06 respectively. P. protegens CY01 and P. chlororaphis CY02 have antibacterial activity against Bacillus subtillis and Staphylococcus aureus. P. chlororaphis CY02 has antagonistic activity against Pyricularia oryzae and anti-tumor cell activity against mouse melanoma B16 cells. CONCLUSION: The isolated P. chlororaphis CY02 has a significant effect on pathogenic bacteria, Pyricularia oryzae and tumor cells.


Assuntos
Antibiose , Pseudomonas/isolamento & purificação , Pseudomonas/fisiologia , Microbiologia do Solo , Animais , Bacillus/fisiologia , Linhagem Celular Tumoral , Camundongos , Fungos Mitospóricos/fisiologia , Dados de Sequência Molecular , Oryza/microbiologia , Filogenia , Doenças das Plantas/microbiologia , Pseudomonas/classificação , Pseudomonas/genética , Staphylococcus aureus/fisiologia
15.
Mikrobiol Z ; 75(4): 69-73, 2013.
Artigo em Ucraniano | MEDLINE | ID: mdl-24006787

RESUMO

The structure of mycobiota (epiphytic and from inner tissues) of Q. robur acorns (580 samples) under conditions of Kyiv Polissya was studied. Acorn samples were collected from oak trees during vegetation period. The epiphytes and mycobiota isolated from inner tissues of acorns was represented by 38 and 20 species, respectively. The majority of fungi were isolated in July. Cosmopolitan and non-specific species Acremonium sp., Alternaria alternata, Cladosporium cladosporioides, Trichoderma harzianum, T. viride and specific ones - Phoma sp. and Phomopsis sp. were isolated from inner acorn tissues. It was established that potential seed and seedling pathogens infect acorns during the process of their formation. The paper is presented in Ukrainian.


Assuntos
Fungos Mitospóricos/isolamento & purificação , Doenças das Plantas/microbiologia , Quercus/microbiologia , Sementes/microbiologia , Fungos Mitospóricos/classificação , Fungos Mitospóricos/patogenicidade , Fungos Mitospóricos/fisiologia , Estações do Ano , Sementes/crescimento & desenvolvimento , Ucrânia
16.
Microb Ecol ; 64(2): 279-90, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22354313

RESUMO

The community of aquatic hyphomycetes associated with decomposing alder leaf litter was studied during autumn-winter in nine headwater reference streams of the Basque Country (northern Spain). In order to study the spatial variability in composition and community structure, three streams from each of three different river basins were compared. The colonization dynamics and community changes throughout the decomposition process were also followed in three of the rivers (one per basin). The taxonomic richness and community structure of these fungi varied among rivers, including similar streams of a given watershed. However, neither species diversity nor total abundance was statistically related to environmental variables. Only the conidial production of two of the species, Flagellospora curvula and Lunulospora curvula appeared to be enhanced by nitrate availability in the water. The taxonomic richness and the reproductive activity (sporulation rate) were positively related to the leaf litter decomposition rate. The changes in conidial production along the process were similar for all the streams and helped explain leaf litter quality dynamics.


Assuntos
Alnus/microbiologia , Biodegradação Ambiental , Ecossistema , Fungos Mitospóricos/fisiologia , Folhas de Planta/metabolismo , Rios/microbiologia , Fungos Mitospóricos/classificação , Fungos Mitospóricos/genética , Fungos Mitospóricos/isolamento & purificação , Folhas de Planta/microbiologia , Rios/química , Espanha , Esporos Fúngicos/fisiologia
17.
Phytopathology ; 102(7): 707-16, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22512466

RESUMO

Pycnidial fungi belonging to the genus Ampelomyces are common intracellular mycoparasites of powdery mildews worldwide. Some strains have already been developed as commercial biocontrol agents (BCAs) of Erysiphe necator and other powdery mildew species infecting important crops. One of the basic, and still debated, questions concerning the tritrophic relationships between host plants, powdery mildew fungi, and Ampelomyces mycoparasites is whether Ampelomyces strains isolated from certain species of the Erysiphales are narrowly specialized to their original mycohosts or are generalist mycoparasites of many powdery mildew fungi. This is also important for the use of Ampelomyces strains as BCAs. To understand this relationship, the nuclear ribosomal DNA internal transcribed spacer (ITS) and partial actin gene (act1) sequences of 55 Ampelomyces strains from E. necator were analyzed together with those of 47 strains isolated from other powdery mildew species. These phylogenetic analyses distinguished five major clades and strains from E. necator that were present in all but one clade. This work was supplemented with the selection of nine inter-simple sequence repeat (ISSR) markers for strain-specific identification of Ampelomyces mycoparasites to monitor the environmental fate of strains applied as BCAs. The genetic distances among strains calculated based on ISSR patterns have also highlighted the genetic diversity of Ampelomyces mycoparasites naturally occurring in grapevine powdery mildew. Overall, this work showed that Ampelomyces strains isolated from E. necator are genetically diverse and there is no indication of strict mycohost associations in these strains. However, these results cannot rule out a certain degree of quantitative association between at least some of the Ampelomyces lineages identified in this work and their original mycohosts.


Assuntos
Ascomicetos/fisiologia , Especificidade de Hospedeiro , Fungos Mitospóricos/fisiologia , DNA Intergênico , Genes Fúngicos , Marcadores Genéticos , Variação Genética , Fungos Mitospóricos/genética , Doenças das Plantas , Vitis/microbiologia
18.
J Infect Chemother ; 18(5): 698-703, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22410856

RESUMO

Biofilms are considered as the most important developmental characteristics in ocular infections. Biofilm eradication is a major challenge today to overcome the incidence of drug resistance. This report demonstrates the in vitro ability of biofilm formation on contact lens by three common keratitis-associated fungal pathogens, namely, Aspergillus fumigatus, Fusarium solani, and Candida albicans. Antifungal sensitivity testing performed for both planktonic cells and biofilm revealed the sessile phenotype to be resistant at MIC levels for the planktonic cells and also at higher concentrations. A prototype lens care solution was also found to be partially effective in eradication of the mature biofilm from contact lenses. Lactoferricin B (Lacf, 64 µg/ml), an antimicrobial peptide, exhibited almost no effect on the sessile phenotype. However, the combinatory effect of Lacf with antifungals against planktonic cells and biofilms of three fungal strains that were isolated from keratitis patients exhibited a reduction of antifungal dose more than eightfold. Furthermore, the effect of Lacf in lens care solution against biofilms in which those strains formed was eradicated successfully. These results suggest that lactoferricin B could be a promising candidate for clinical use in improving biofilm susceptibility to antifungals and also as an antibiofilm-antifungal additive in lens care solution.


Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Infecções Oculares Fúngicas/microbiologia , Ceratite/microbiologia , Lactoferrina/farmacologia , Fungos Mitospóricos/efeitos dos fármacos , Fungos Mitospóricos/fisiologia , Sequência de Aminoácidos , Soluções para Lentes de Contato/química , Soluções para Lentes de Contato/farmacologia , Lentes de Contato/microbiologia , Humanos , Testes de Sensibilidade Microbiana , Microscopia de Fluorescência , Dados de Sequência Molecular , Fenótipo
19.
Exp Parasitol ; 130(3): 300-5, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22143088

RESUMO

Ticks are serious health threats for humans, and both domestic and wild animals. Ticks are controlled mostly by application of chemical products; but these acaricides have several negative side effects, including toxicity to animals, environmental contamination, and induction of chemical resistance in some tick populations. Entomopathogenic fungi infect arthropods in nature and can occur at enzootic or epizootic levels in their host populations. Laboratory studies clearly demonstrate that these fungi can cause high mortality in all developmental stages of several tick species, and also reduce oviposition of infected engorged females. Tick mortality following application of fungi in the field, however, often is less than that suggested by laboratory tests. This is due to many negative biotic and climatic factors. To increase efficacy of fungal agents for biological control of ticks under natural conditions, several points need consideration: (1) select effective isolates (viz., high virulence; and tolerance to high temperature, ultraviolet radiation and desiccation); (2) understand the main factors that affect virulence of fungal isolates to their target arthropods including the role of toxic metabolites of the fungal isolates; and (3) define with more precision the immune response of ticks to infection by entomopathogenic fungi. The current study reviews recent literature on biological control of ticks, and comments on the relevance of these results to advancing the development of fungal biocontrol agents, including improving formulation of fungal spores for use in tick control, and using entomopathogenic fungi in integrated pest (tick) management programs.


Assuntos
Fungos Mitospóricos/fisiologia , Controle Biológico de Vetores/métodos , Carrapatos/microbiologia , Animais , Beauveria/genética , Beauveria/patogenicidade , Beauveria/fisiologia , Feminino , Variação Genética , Humanos , Metarhizium/genética , Metarhizium/patogenicidade , Metarhizium/fisiologia , Fungos Mitospóricos/genética , Fungos Mitospóricos/patogenicidade , Micotoxinas/metabolismo , Micotoxinas/toxicidade , Carrapatos/fisiologia , Virulência
20.
Mycologia ; 104(3): 613-22, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22123653

RESUMO

Aquatic hyphomycetes, a group of polyphyletic fungi, have been reported in streams contaminated with metals. This tolerance to metal contamination however can result in limited performance and limited ability to cope with additional environmental change. The predicted increase in water temperature, as a consequence of global warming, will have an additional effect on many streams. The sensitivity to temperature of strains of three aquatic hyphomycete species isolated from a metal-contaminated stream and an uncontaminated stream was assessed by determining their radial growth and activity (conidial production, oxygen consumption, mycelial biomass accumulation, fine particulate organic matter [FPOM] production, and microbial induced leaf mass loss) at 13 C (present water temperature in autumn) and at 18 C (predicted water temperature under global warming). Growth and reproductive activity generally were depressed for the strains isolated from the metal-contaminated stream when compared with those isolated from the unpolluted stream. These differences however were not translated into differences in FPOM production and leaf-litter mass loss, indicating that the strains isolated from the contaminated stream can decompose leaf litter similar to those of the reference stream. The 5 C increase in temperature stimulated fungal activity and litter decomposition, irrespective of species and strain. This might have strong effect on aquatic food-web and ecosystem functioning under global warming because increases in litter decomposition might lead to food shortage for higher trophic levels. The sensitivity to temperature depended on the response variable, species and strain. FPOM production was the variable most sensitive to temperature across strains and species and that for which temperature sensitivities differed most between strains. Fungal tolerance to metal contamination affects the extent to which its functions are stimulated by an increase in temperature, constituting an additional cost of metal tolerance.


Assuntos
Metais , Fungos Mitospóricos/crescimento & desenvolvimento , Rios/microbiologia , Temperatura , Poluição Química da Água , Alnus/microbiologia , Biomassa , Mudança Climática , Metais/efeitos adversos , Fungos Mitospóricos/efeitos dos fármacos , Fungos Mitospóricos/isolamento & purificação , Fungos Mitospóricos/fisiologia , Micélio/efeitos dos fármacos , Micélio/crescimento & desenvolvimento , Micélio/fisiologia , Oxigênio/metabolismo , Folhas de Planta/microbiologia , Rios/química , Especificidade da Espécie , Esporos Fúngicos/efeitos dos fármacos , Esporos Fúngicos/crescimento & desenvolvimento , Esporos Fúngicos/fisiologia , Microbiologia da Água , Poluição Química da Água/efeitos adversos
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