RESUMEN
A marine strain of Penicillium waksmanii Zaleski was isolated from a sample of seawater from shellfish-farming area in the Loire estuary (France). The in vitro marine culture showed an important antifungal activity. Bioassay-guided fractionation was used to purify the crude extract. Dereplication by electrospray-ion trap/mass spectrometry (ESI-IT/MS) afforded the identification of the antifungal compound, after a semi-purification consisting of two stages. A comparison of the ionic composition between the active and the non-active fractions allowed the detection of a monocharged ion at m/z 353 containing a chlorine atom, which could be attributed to the antifungal griseofulvin [C17H17ClO6+H]+. Multi-stage fragmentation (MSn) confirmed the identity of the m/z 353 ion of the antifungal fraction as griseofulvin. It is the first description of griseofulvin production by a strain of P. waksmanii and the first chemical study of a strain of this species isolated from marine temperate cold water.
Asunto(s)
Antifúngicos/aislamiento & purificación , Griseofulvina/aislamiento & purificación , Penicillium/metabolismo , Agua de Mar/microbiología , Antifúngicos/química , Antifúngicos/metabolismo , Cromatografía en Gel , Cromatografía Líquida de Alta Presión , Griseofulvina/química , Griseofulvina/metabolismo , Penicillium/química , Espectrometría de Masa por Ionización de Electrospray , Microbiología del AguaRESUMEN
A new cytotoxic trichothecene sesquiterpene, verrol 4-acetate, was isolated, along with known macrocyclic trichothene mycotoxins and medicinal styrylpyrones, from cultures of a new deuteromycete Acremonium neo-caledoniae Roquebert et Dupont n. sp., taken from drifting wood in the southwestern lagoon of New Caledonia.
Asunto(s)
Acremonium/química , Citotoxinas/aislamiento & purificación , Micotoxinas/aislamiento & purificación , Tricotecenos/aislamiento & purificación , Citotoxinas/química , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Espectroscopía de Resonancia Magnética , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Micotoxinas/química , Tricotecenos/química , Células Tumorales CultivadasRESUMEN
To determine whether toxic metabolites produced by fungi could cause shellfish toxicities, mussels were contaminated in laboratory conditions by sterile filtrates of a liquid culture of a strain of the fungus Trichoderma koningii previously isolated from a shellfish, the cockle (Cerastoderma edule). Mussels were kept in aerated natural seawater and fed with a culture of the microalga Isochrysis galbana, to which a filtrate of liquid fungal culture was added. Mussels were exposed to contamination for 7 days at 16 or 20 degrees C and extractions were then performed and their activity tested on blowfly larvae. The same toxicity was found in the fungal filtrate and the shellfish, indicating bioaccumulation. The digestive gland was the most toxic part of the mussel, confirming contamination by filtration. Treated mussels produced a mucus which appeared to be a means of eliminating toxic metabolites.
Asunto(s)
Bivalvos/metabolismo , Contaminación de Alimentos/análisis , Toxinas Marinas/metabolismo , Micotoxinas/metabolismo , Mariscos/análisis , Trichoderma/metabolismo , Animales , Cnidarios , Eucariontes/metabolismo , Larva , Moco/metabolismo , TemperaturaRESUMEN
When cell membranes of Lentinus edodes mycelium were rapidly frozen at either 50 or 160°C/min, viability was lost and this correlated with rupture of the plasmalemma and residual membrane material and with alterations in the organelles. Although with slow cooling (1°C/min) 80% of the samples recovered viability, some cells still showed similar changes to those cooled rapidly, indicating that individual cells of the mycelium do not respond in the same way.
RESUMEN
The authors report fungal contamination of the water delivery system in one of their dialysis centers. They emphasize the insufficiency of the legal recommendations for water analysis, as well as the economical and logistical consequences of this type of contamination. Finally, they suggest disinfection procedures allowing eradication of fungi.
Asunto(s)
Hongos/aislamiento & purificación , Diálisis Renal , Abastecimiento de Agua/normas , Desinfección , Humanos , Microbiología del AguaRESUMEN
Antisera were obtained from a rabbit immunized with Penicillium verrucosum var. verrucosum. These antisera were characterized by immunofluorescence and by indirect enzyme-linked immunosorbent assay for their reactivity with 44 strains of moulds. Antigenically, P. verrucosum var. verrucosum (subgenus Penicillium) appears to be similar to strains belonging to subgenus Furcatum, but strongly different from Penicillium frequentans (subgenus Aspergilloides). Specific absorption of antibodies to antigens confirmed the existence of similar biochemical structures on Penicillium frequentans, Aspergillus versicolor, and Aspergillus fumigatus. Immunological procedures may thus significantly contribute to refine the taxonomic classification of moulds.