16 research outputs found

    Life Cycle of the Oriental Compost Worm Perionyx Excavatus (Oligochaeta)

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    In order to exploit the concept of using vermiculture as biotechnology for waste control and protein production, the life cycle of the vermicomposting species, Perionyx excavatus, was studied. The development, growth and reproduction of P. excavatus  were investigated. Urine free cattle manure with a moisture content of 76-83% and a temperature of 25°C was used as substrate. Data were gathered over a period of 300 days. It was found that mating is not a prerequisite for cocoon production, which starts at the mean age of 24 days. Maturation was attained at the age of approximately 21 days. Cocoons were produced at a mean rate of 1,1 cocoons per worm per day. The mean incubation period of cocoons produced by batches of worms was 18,7 days with a mean hatching success of 63,4%. The mean incubation period of cocoons produced by single worms was 20,4 days with a mean hatching success of 40,4%. As a rule only one worm hatched per cocoon. The life cycle of this species is presented diagrammatically

    Efficacy of Origanum essential oils for inhibition of potentially pathogenic fungi

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    This study aimed to assess the efficacy of O. vulgare L. and O. majorana L. essential oil in inhibiting the growth and survival of potentially pathogenic fungal strains and also sought to evaluate the possible mechanisms involved in the establishment of the antifungal property of the tested essential oils through assays of osmotic stability and morphogenesis. Test strains included in this study were Candida albicans ATCC 7645, C. tropicalis LM-14, C. krusei LM-09, Cryptococcus neoformans FGF-5, Aspergillus flavus LM-02, A. fumigatus IPP-21, T. rubrum ATCC 28184, T. mentagrophytes LM-64, Microsporum gypseum ATCC 184, M. canis LM-36 and Cladosporium herbarium ATCC 26362. O. vulgare essential oil presented a MIC value of 80 µL/mL, while for O. majorana this was 160 µL/mL. C. krusei LM-09 was the only strain resistant to all assayed concentrations of both essential oils. O. vulgare and O. majorana essential oil at their MIC values provided a cidal effect against C. albicans ATCC 7645 after 4 h of exposure. O. vulgare essential oil at 80 µL/mL exhibited 100 % inhibition of the radial mycelia growth of T. rubrum ATCC 28184 and M. canis LM-36 for 14 days. Assayed fungus strain protected by sorbitol (osmo-protectant agent) grew in media containing higher concentrations of O. vulgare and O. majorana essential oil in comparison to media without sorbitol, suggesting some specificity of these essential oils for targeting cell wall in the fungi cell. Main morphological changes observed under light microscopy provided by the essential oil of O. vulgare in A. flavus LM-02 were decreased conidiation, leakage of cytoplasm, loss of pigmentation and disrupted cell structure indicating fungal wall degeneration. These results suggest that essential oils from Origanum could be regarded as a potential antifungal compound for controlling the growth of pathogen fungi and the occurrence of mycoses.<br>O objetivo deste estudo foi observar a eficácia do óleo essencial de O. vulgare L. e O. majorana L. na inibição do crescimento e sobrevivência de cepas de fungos potencialmente patogênicas, bem como avaliar os possíveis mecanismos envolvidos no estabelecimento da propriedade antifúngica dos óleos essenciais testados através do ensaio de estabilidade osmótica e morfogênese. As cepas fúngicas utilizadas neste estudo foram Candida albicans ATCC 7645, C. tropicalis LM-14, C. krusei LM-09, Cryptococcus neoformans FGF-5, Aspergillus flavus LM-02, A. fumigatus IPP-21, T. rubrum ATCC 28184, T. mentagrophytes LM-64, Microsporum gypseum ATCC 184, M. canis LM-36 e Cladosporium herbarium ATCC 26362. O óleo essencial de O. vulgare apresentou valor de CIM de 80 µL/mL, enquanto o óleo essencial de O. majorana apresentou valor de CIM de 160 µL/mL. C. krusei LM-09 apresentou-se como a única cepa resistente a todas as concentrações ensaiadas de ambos os óleos essenciais. Os óleos essenciais testados quando ensaiadas em seu valor de CIM causaram um efeito fungicida contra C. albicans ATCC 7645 após 4 h de exposição. O óleo essencial de O. vulgare na concentração de 80 µL/mL exibiu uma total inibição do crescimento micelial radial de T. rubrum ATCC 28184 e M. canis LM-36 ao longo de 14 dias. As cepas fúngicas ensaiadas quando tratadas com sorbitol (agente osmo-protetor) foram capazes de crescer em meio adicionado de mais altas concentrações dos óleos essenciais quando comparados ao meio não adicionado de sorbitol, sugerindo especificidade destes produtos a parede celular como alvo na célula fúngica. As principais alterações causadas pelo óleo essencial de O. vulgare sobre a morfologia de A. flavus LM-02 foram diminuída conidiação, perda de citoplasma, perda de pigmentação e ruptura da estrutura celular indicando degeneração da parede celular fúngica. Estes resultados sugerem que óleos essenciais de espécies de Origanum poderiam ser considerados como potenciais antifúngicos para o controle de fungos patógenos e ocorrência de micoses

    One fungus, one name: defining the genus Fusarium in a scientifically robust way that preserves longstanding use

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    In this letter, we advocate recognizing the genus Fusarium as the sole name for a group that includes virtually all Fusarium species of importance in plant pathology, mycotoxicology, medicine, and basic research. This phylogenetically guided circumscription will free scientists from any obligation to use other genus names, including teleomorphs, for species nested within this clade, and preserve the application of the name Fusarium in the way it has been used for almost a century. Due to recent changes in the International Code of Nomenclature for algae, fungi, and plants, this is an urgent matter that requires community attention. The alternative is to break the longstanding concept of Fusarium into nine or more genera, and remove important taxa such as those in the F. solani species complex from the genus, a move we believe is unnecessary. Here we present taxonomic and nomenclatural proposals that will preserve established research connections and facilitate communication within and between research communities, and at the same time support strong scientific principles and good taxonomic practice
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