The citrus black spot (CBS), caused by Phyllosticta citricarpa, is one of the most important citrus diseases in subtropical regions of Africa, Asia, Oceania, and the Americas, and fruits with CBS lesions are still subject to quarantine regulations in the European Union. Despite the high application of fungicides, the disease remains present in the citrus crops of Central and South America. In order to find alternatives to help control CBS and reduce the use of fungicides, we explored the antifungal potential of endophytic actinomycetes isolated from the Brazilian medicinal plant Vochysia divergens found in the Pantanal biome. Two different culture media and temperatures were selected to identify the most efficient conditions for the production of active secondary metabolites. The metabolites produced by strain Microbacterium sp. LGMB471 cultured in SG medium at 36 °C considerably inhibited the development of P. citricarpa. Three isoflavones and five diketopiperazines were identified, and the compounds 7-O-β-D-glucosyl-genistein and 7-O-β-D-glucosyl-daidzein showed high activity against P. citricarpa, with the MIC of 33 μg/mL and inhibited the production of asexual spores of P. citricarpa on leaves and citrus fruits. Compounds that inhibit conidia formation may be a promising alternative to reduce the use of fungicides in the control of CBS lesions, especially in regions where sexual reproduction does not occur, as in the USA. Our data suggest the use of Microbacterium sp. LGMB471 or its metabolites as an ecological alternative to be used in association with the fungicides for the control of CBS disease.
- MeSH
- Actinomycetales chemie MeSH
- Ascomycota účinky léků MeSH
- Citrus mikrobiologie MeSH
- diketopiperaziny izolace a purifikace farmakologie MeSH
- fungicidy průmyslové izolace a purifikace farmakologie MeSH
- isoflavony izolace a purifikace farmakologie MeSH
- kultivační média MeSH
- listy rostlin mikrobiologie MeSH
- mikrobiální testy citlivosti MeSH
- nemoci rostlin mikrobiologie MeSH
- sekundární metabolismus MeSH
- spory hub účinky léků MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Asie MeSH
- Brazílie MeSH
- Spojené státy americké MeSH
Three different transformation strategies were tested and compared in an attempt to facilitate and improve the genetic transformation of Acremonium chrysogenum, the exclusive producer of the pharmaceutically relevant β-lactam antibiotic cephalosporin C. We investigated the use of high-voltage electric pulse to transform germinated conidia and young mycelium and compared these procedures with traditional PEG-mediated protoplast transformation, using phleomycin resistance as selection marker in all cases. The effect of the field strength and capacitance on transformation frequency and cell viability was evaluated. The electroporation of germinated conidia and young mycelium was found to be appropriate for transforming A. chrysogenum with higher transformation efficiencies than those obtained with the conventional protoplast-based transformation procedures. The developed electroporation strategy is fast, simple to perform, and highly reproducible and avoids the use of chemicals toxic to cells. Electroporation of young mycelium represents an alternative method for transformation of fungal strains with reduced or no sporulation, as often occurs in laboratory-developed strains in the search for high-yielding mutants for industrial bioprocesses.
- MeSH
- Acremonium účinky léků genetika metabolismus MeSH
- bakteriální léková rezistence MeSH
- cefalosporiny biosyntéza MeSH
- elektroporace metody MeSH
- fleomyciny farmakologie MeSH
- mikrobiální viabilita MeSH
- mycelium účinky léků genetika metabolismus MeSH
- protoplasty fyziologie MeSH
- spory hub účinky léků genetika metabolismus MeSH
- transformace genetická * MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
The inactivation of four micromycete species by action of non-thermal plasma was followed. Two sources of plasma were compared, namely, positive corona discharge and dielectric barrier discharge. The corona discharge appeared as suitable for fungal spore inactivation in water suspension, whereas the barrier discharge inactivated spores on the surface of cultivation agar. Cladosporium sphaerospermum was the most sensitive, being inactivated within 10 min of exposure to plasma, whereas Aspergillus oryzae displayed decrease in viable cell count only, the complete inactivation was not achieved even after 40 min of exposure. Intermediate sensitivity was found for Alternaria sp. and Byssochlamys nivea. The significant delay of growth was observed for all fungi after exposure to sublethal dose of plasma, but we failed to express this effect quantitatively.
The present study was conducted to evaluate the methanolic extracts from several plant leaves widely used in traditional medicine to cure digestive tract disorders and in the self-medication of wild animals such as non-human primates, namely Archidendron fagifolium, Diospyros sumatrana, Shorea sumatrana, and Piper betle leaves, with regard to their antimicrosporidial activity against Encephalitozoon cuniculi in immunocompetent BALB/c mice determined using molecular detection of microsporidial DNA (qPCR) in various tissues and body fluids of infected, treated mice. Of the plant extracts tested, Diospyros sumatrana provided the most promising results, reducing spore shedding by 88% compared to untreated controls. Moreover, total burden per 1 g of tissue in the D. sumatrana extract-treated group reached 87% reduction compared to untreated controls, which was comparable to the effect of the standard drug, Albendazole. This data represents the baseline necessary for further research focused on determining the structure, activity and modes of action of the active compounds, mainly of D. sumatrana, enabling subsequent development of antimicrosporidial remedies.
- MeSH
- albendazol farmakologie terapeutické užití MeSH
- antifungální látky farmakologie terapeutické užití MeSH
- Cercopithecus aethiops MeSH
- dimethylsulfoxid farmakologie terapeutické užití MeSH
- Diospyros chemie MeSH
- Dipterocarpaceae chemie MeSH
- DNA fungální izolace a purifikace MeSH
- Encephalitozoon cuniculi účinky léků MeSH
- encephalitozoonóza farmakoterapie MeSH
- Fabaceae chemie MeSH
- feces parazitologie MeSH
- gastrointestinální trakt mikrobiologie MeSH
- imunokompetence MeSH
- listy rostlin chemie MeSH
- myši inbrední BALB C MeSH
- myši MeSH
- Piper betle chemie MeSH
- rostlinné extrakty farmakologie terapeutické užití MeSH
- spory hub účinky léků MeSH
- Vero buňky MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Indonésie MeSH
Coniochaeta pulveracea is a dimorphic lignicolous fungus that has mostly been isolated from decaying wood. However, relatively little work was conducted on the conditions for the dimorphic switch or the biological interactions of the fungus in its yeast-like microcyclic growth phase. Therefore, in this study, the microcyclic conidiation of C. pulveracea strains and representatives of the closely related species, Coniochaeta boothii and Coniochaeta subcorticalis, was studied under different environmental conditions. The strains were found to exhibit hyphal growth on solid substrates and underwent a dimorphic switch to produce microcycle conidiation upon transfer to a liquid medium which differed in physico-chemical composition compared to the original solid medium. Factors that were found to contribute to this dimorphic switch were temperature, pH and the presence of complex nitrogen sources such as casamino acids and peptone in the medium. However, C. pulveracea showed intraspecific differences with regard to its response to changes in the physico-chemical environment. The interactions of microcyclic Coniochaeta strains with selected yeasts, such as representatives of Meyerozyma guilliermondii and Cryptococcus neoformans, were subsequently studied in complex liquid media and it was found that, depending on medium composition, the microcyclic Coniochaeta exerted different effects on the different yeasts strains. In some co-cultures, a positive effect on yeast growth was observed, whilst in other cases microcyclic Coniochaeta inhibited yeast growth.
- MeSH
- Ascomycota cytologie účinky léků růst a vývoj účinky záření MeSH
- Cryptococcus neoformans růst a vývoj MeSH
- hyfy cytologie účinky léků růst a vývoj účinky záření MeSH
- koncentrace vodíkových iontů MeSH
- kultivační média chemie MeSH
- mikrobiální interakce MeSH
- Saccharomycetales růst a vývoj MeSH
- sloučeniny dusíku metabolismus MeSH
- spory hub cytologie účinky léků růst a vývoj účinky záření MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
The yeast strains VKM Y-2977 and VKM Y-2978, derived from the isolate Pa-202, were examined for their physiological properties and mycocin sensitivities and studied by light, phase-contrast, fluorescence, transmission and scanning electron microscopy. The cells of the first strain produced long stalk-like conidiophores, whereas the cells of the second one had the appearance of a typical budding yeast under the light microscope. Transmission and scanning electron microscopy showed the formation of stalk-like conidiophores and long necks in VKM Y-2977, similar in appearance to Fellomyces fuzhouensis. The actin cytoskeleton, microtubules and nuclei were similar as well, but due to presence of a capsule, they were not clearly visible. The second isolate, VKM Y-2978, had very short stalk-like conidiophores, and the neck, microtubules and actin cables were shorter as well. The actin patches, actin cables, and microtubules were similar in VKM Y-2977 and VKM Y-2978 and not clearly visible. The physiological characteristics and mycocin sensitivity patterns, together with the microscopic structures and ultrastructures, led us to conclude that both strains belong to Fellomyces penicillatus, even though they differ in the lengths of their stalk-like conidiophores and necks.
- MeSH
- aktiny ultrastruktura MeSH
- antifungální látky farmakologie MeSH
- Basidiomycota klasifikace účinky léků růst a vývoj ultrastruktura MeSH
- buněčné jádro ultrastruktura MeSH
- cytoplazma ultrastruktura MeSH
- mikroskopie MeSH
- mikrotubuly ultrastruktura MeSH
- spory hub účinky léků růst a vývoj ultrastruktura MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: The aim of this basic study was to investigate by scanning electron microscopy the effects of cytoskeleton inhibitors on conidiogenesis and capsule in the yeast Fellomyces fuzhouensis CBS 8243, related to Cryptococcus neoformans. METHODS: Cells were treated by methyl benzimidazole-2-ylcarbamate (BCM) and latrunculin A (LAT) in yeast extract peptone dextrose medium and examined by scanning electron microscopy. RESULTS: During conidiogenesis, mother cells covered by capsule formed hypha-like stalks and at the hyphal tip yeast-like conidium developed. LAT blocked both stages of conidiogenesis. Inhibited mother cells and conidia became spherical and their capsule disappeared. BCM did not block formation of conidia that were neckless, or affect capsule. Combined application of LAT and BCM blocked both stages of conidiogenesis, cells became spherical and their capsule disappeared. CONCLUSION: Yeast cells with disrupted actin cytoskeleton do not reproduce by conidiogenesis and do not retain inherited cell shape and capsule.
- MeSH
- Basidiomycota účinky léků ultrastruktura MeSH
- bicyklické sloučeniny heterocyklické farmakologie MeSH
- cytoskelet účinky léků ultrastruktura MeSH
- mikroskopie elektronová rastrovací metody MeSH
- spory hub účinky léků ultrastruktura MeSH
- thiazolidiny farmakologie MeSH
- tvar buňky účinky léků MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
The allelopathic potential of an artificially applied allelochemical, benzoic acid, on in vitro Fusarium oxysporum f.sp. niveum (a soil-borne pathogen causing watermelon wilt) was evaluated. Benzoic acid strongly inhibited its growth, sporulation and conidia germination, whereas it stimulated virulence factors of this pathogen. The biomass was reduced by 83-96 % and the conidia germinating rate and conidia production rate were decreased by 100 % at a concentration of >200 mg/L. However, phytopathogenic enzyme activities and mycotoxin production were stimulated with an increase of 10.2-1250 % for enzyme activities and 610-2630 % for mycotoxin yield.
- MeSH
- Citrullus mikrobiologie MeSH
- financování organizované MeSH
- Fusarium MeSH
- fylogeneze MeSH
- kyselina benzoová farmakologie MeSH
- molekulární sekvence - údaje MeSH
- mykotoxiny metabolismus MeSH
- nemoci rostlin mikrobiologie MeSH
- rostlinné exsudáty farmakologie MeSH
- spory hub fyziologie účinky léků MeSH
- MeSH
- alkaloidy aplikace a dávkování farmakologie MeSH
- houby účinky léků MeSH
- klíčení účinky léků MeSH
- spory hub účinky léků MeSH
- Publikační typ
- techniky in vitro MeSH
