RESUMO
Megacoelomyces (type species: Megacoelomyces sanchezii), an ascomycete asexual morph infecting Myrcia fenzliana (Myrtaceae) from the Brazilian Cerrado, is described as a new genus in the Phaeosphaeriaceae (Pleosporales, Dothideomycetes, Ascomycota), based on multilocus phylogeny (three nuclear ribosomal DNA and two protein-coding genes) in addition to morphological (light and scanning electron microscopy) and ecological data.
Assuntos
Classificação , Fungos Mitospóricos , Ascomicetos/classificação , Ascomicetos/citologia , Ascomicetos/genética , Ascomicetos/ultraestrutura , Brasil , DNA Fúngico/genética , DNA Ribossômico/genética , Genes Fúngicos , Microscopia Eletrônica de Varredura , Fungos Mitospóricos/classificação , Fungos Mitospóricos/citologia , Fungos Mitospóricos/genética , Fungos Mitospóricos/ultraestrutura , Myrtaceae/microbiologia , FilogeniaRESUMO
Microbial transformation of beta-amyrin by growing cells of the fungus Lecanicillium muscarinium (former Cephalosporium aphidicola) was successfully accomplished after 15 days of incubation with orbital shaking at 120 rpm. Two products purified by column chromatography were identified by 1H and 13C mono- and bi-dimensional nuclear magnetic resonance as 3beta-hydroxy-olean-12-en-11-one and 11alpha,12alpha-oxidotaraxerol; these later formed new compounds formed by an interesting oxidative rearrangement of the starting material, probably via an initial hydroxylation at C-11.
Assuntos
Fungos Mitospóricos/citologia , Fungos Mitospóricos/metabolismo , Ácido Oleanólico/análogos & derivados , Biotransformação , Estrutura Molecular , Ácido Oleanólico/química , Ácido Oleanólico/metabolismo , OxirreduçãoRESUMO
The aim of this study was to select virulent strains of microfungi against Leucoagaricus gongylophorus, a symbiotic fungus cultivated by leaf-cutting ants. The results from in vitro assays showed that microfungal strains had a variable and significant impact on the colony development of L. gongylophorus. Specifically, Trichoderma harzianum, Escovopsis weberi CBS 810.71 and E. weberi A088 were more effective, inhibiting the L. gongylophorus colonies by 75, 68 and 67%, respectively (P < 0.05) after 15 days. Strain E. weberi A086 and Acremonium kiliense were less effective: 43 and 26%, respectively (P < 0.05). In spite of the current negative perspective of a microbiological control approach for these ants, the present work discusses the possibility of using mycopathogenic fungi for the control of these insects, and points out the importance of encouraging more studies in this area.
Assuntos
Formigas/microbiologia , Basidiomycota/fisiologia , Controle de Insetos/métodos , Fungos Mitospóricos/fisiologia , Animais , Basidiomycota/citologia , Fungos Mitospóricos/citologia , SimbioseRESUMO
The genus Piricauda comprises eight species characterized by monotretic conidiogenous cells and micronematous arched conidiophores: P. cochinensis, P. cubensis, P. longispora, P. mexicana, P. paraguayensis, P. pseudarthriae, P. taiwanensis, and P. vulcanensis sp. nov. P. caribensis is transferred to Acrodictys. Species usually colonize dead petioles and rachides of palms in tropical and subtropical areas, but can also be found on branches and leaves of different trees. The species are illustrated and briefly described, and a key to them is provided.
Assuntos
Fungos Mitospóricos/classificação , Árvores/microbiologia , Fungos Mitospóricos/citologia , Especificidade da EspécieRESUMO
Seimatoantlerium gen. nov., type species, S. tepuiense sp. nov. is proposed for an acervular fungus producing 4-septate, holoblastic conidia with 6-8 unbranched, apical appendages that dehisce as an appendage apparatus and also commonly possessing one or two exogenous basal appendages as well as a pedicel. It is compared with Seimatosporium, Seimatosporiopsis, and other genera. It is epiphytic on Maguireothamnus speciosus, a rubiaceous plant endemic to the tepuis of southeastern Venezuela. It produces the anti-oomycetous anticancer compound, taxol, as shown by immunological and spectroscopic methods. Taxol production is discussed relative to the ability of this fungus to exist in an extremely moist ecosystem, as well as to its relationship to other plant associated fungi.
Assuntos
Antineoplásicos Fitogênicos/isolamento & purificação , Fungos Mitospóricos/química , Paclitaxel/isolamento & purificação , Plantas/microbiologia , Cromatografia em Camada Fina , Ecologia , Espectrometria de Massas , Fungos Mitospóricos/citologia , Fungos Mitospóricos/crescimento & desenvolvimento , Kit de Reagentes para DiagnósticoRESUMO
Seimatoantlerium gen. nov., type species, S.tepuiense sp. nov. is proposed for an acervular fungus producing 4-septate, holobastic conidia with 6-8 unbranched, apical appendages that dehisce as an appendage apparatus and also commonly possessing one or two exogenous basal appendages as well as a pedicel. It is compared with Seimatosporium, Seimatosporiopsis, and other genera. It is epiphytic on Maguireothamnus speciosus, a rubiaceous plant endemic to the tepuis of southeastern Venezuela. It produces the anti-oomycetous anticancer compound, taxol, as shown by immunological and spectroscopic methods. Taxol production is discussed relative to the ability of this fungus to exist in an extremely moist ecosystem, as well as to its relationship to other plant associated fungi. (AU)
Assuntos
Paclitaxel/isolamento & purificação , Fungos Mitospóricos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Plantas/microbiologia , Cromatografia em Camada Fina , Ecologia , Fungos Mitospóricos/citologia , Fungos Mitospóricos/crescimento & desenvolvimento , Kit de Reagentes para Diagnóstico , Espectrometria de MassasRESUMO
A case of peritonitis due to Curvularia lunata during continuous ambulatory peritoneal dialysis is reported. Diagnosis was established by culture of dialysis effluent and peritoneal exudate, and was also confirmed through histological examination.
Assuntos
Fungos Mitospóricos/patogenicidade , Micoses/etiologia , Diálise Peritoneal Ambulatorial Contínua/efeitos adversos , Peritonite/microbiologia , Complicações do Diabetes , Humanos , Pessoa de Meia-Idade , Fungos Mitospóricos/citologia , Fungos Mitospóricos/isolamento & purificação , Micoses/diagnóstico , Peritonite/diagnóstico , Peritonite/etiologia , Insuficiência Renal/etiologia , Insuficiência Renal/terapiaRESUMO
Two strains of an undescribed, soil-borne species of the genus Myxozyma were recovered. They differ from other accepted species of this genus in their carbon assimilation pattern, mol% G+C and low extent of DNA complementary. A description of the new species, Myxozyma neotropica, and a key to the species accepted in the genus are given.
Assuntos
Fungos Mitospóricos/classificação , Microbiologia do Solo , Composição de Bases , Metabolismo dos Carboidratos , Costa Rica , Meios de Cultura , DNA Fúngico/química , Fungos Mitospóricos/citologia , Fungos Mitospóricos/isolamento & purificação , Fungos Mitospóricos/fisiologiaRESUMO
Lesioned skin tissues from a female Caiabi indian with lobomycosis were processed for routine electron microscopy using, in the initial steps, solutions containing 2% lanthanum nitrate. The pattern of tracer distribution suggests that the tracer penetrates into the cavity containing the parasite through exocytotic-like apertures situated at the cell wall outer region. The tracer also infiltrates the virtual space between the cell wall and its recovering membrane, spreading over varying areas of the outer surface of the cell wall. The contrast imparted to the pericellular macrophage space by the lanthanum nitrate enabled easy localization of fibrillar, cell wall derived material which reaches the adjacent extracellular milieu.
Assuntos
Lantânio , Fungos Mitospóricos/citologia , Paracoccidioides/citologia , Adulto , Parede Celular , Dermatomicoses/patologia , Feminino , Humanos , Microscopia Eletrônica , Paracoccidioidomicose/patologia , Fagocitose , Pele/patologia , Pele/ultraestruturaRESUMO
The dimorphism of Scopulariopsis brevicaulus was induced in malt agar (Oxoid), at 37 degrees C and 5-10% rate of CO2. Six cultures of S. brevicaulus were converted from hyphae to yeast-like cells by the following processes: One was that the hyphae formed intercalar and terminal chlamydoconidia-like cells. These cells increased in size, gained double contour and gave rise to budding cells. The other process was via conidia that assumed yeast characteristics. So, a transformation cycle M----Y was proposed. The yeast-like form presented slow reversion to the mould phase, standing, many times, in transition forms. A high concentration of sugars, peptone, temperature of cultivation of 37 degrees C and 5-10% rate of CO2 seem to be favourable factors for the maintenance of the yeast phase. Ethanol, E.D.T.A., potassium nitrate, temperature of 25 degrees C and aerobiosis are considered favourable factors to conversion of the mould phase.