Asunto(s)
Benzopiranos/toxicidad , Citrinina/toxicidad , Micotoxinas/toxicidad , Animales , Peso Corporal/efectos de los fármacos , Ciego/efectos de los fármacos , Citrinina/efectos adversos , Citrinina/envenenamiento , Cobayas , Túbulos Renales Proximales/efectos de los fármacos , Dosificación Letal Mediana , Ratones , Micotoxinas/efectos adversos , Micotoxinas/envenenamiento , Necrosis , Conejos , Ratas , PorcinosAsunto(s)
Benzopiranos/toxicidad , Citrinina/toxicidad , Administración Oral , Animales , Peso Corporal/efectos de los fármacos , Citrinina/administración & dosificación , Dimetilsulfóxido/toxicidad , Etanol/toxicidad , Inyecciones Intraperitoneales , Inyecciones Subcutáneas , Riñón/patología , Ratones , Ratones Endogámicos ICRAsunto(s)
Benzopiranos/toxicidad , Caproatos/toxicidad , Citrinina/toxicidad , Ocratoxinas/toxicidad , Ácido Penicílico/toxicidad , Animales , Sinergismo Farmacológico , Femenino , Riñón/metabolismo , Dosificación Letal Mediana , Hígado/metabolismo , Ratones , Ácido Orótico/metabolismo , ARN/biosíntesisAsunto(s)
Aflatoxinas/toxicidad , Enfermedades Transmitidas por los Alimentos , Zea mays , Factores de Edad , Animales , Peso Corporal , Femenino , Microbiología de Alimentos , Enfermedades Transmitidas por los Alimentos/metabolismo , Enfermedades Transmitidas por los Alimentos/mortalidad , Metabolismo de los Lípidos , Hígado/metabolismo , Masculino , Ratones , Factores SexualesRESUMEN
One-hundred clinical isolates of Serratia marcescens were tested for susceptibility to cephalothin, carbenicillin, ticarcillin, ampicillin, and cefoxitin. The majority of the 100 isolates (>/=70%) were susceptible to carbenicillin, ticarcillin, and cefoxitin; less than one-half were susceptible to ampicillin; none were susceptible to cephalothin. Ten isolates from the 100 organisms tested were selectively assayed for their beta-lactamase activity. Enzyme activity was measured using either iodometric or spectrophotometric methods, and the microbiological assay technique. It was concluded that beta-lactamase production was not the sole determinant in beta-lactam antibiotic resistance. Resistance without demonstrable beta-lactamase was evident in strains for cephalothin, ampicillin, and cefoxitin. In addition, one strain which was susceptible to all antibiotics except cephalothin, elaborated considerable beta-lactamase activity.
Asunto(s)
Amidohidrolasas/metabolismo , Antibacterianos/farmacología , Cefalosporinasa/metabolismo , Serratia marcescens/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Pigmentación , Serratia marcescens/enzimologíaRESUMEN
A rapid method for preparing cell-free extracts of Aspergillus ochraceus was developed. Mycelial mats were prefrozen in liquid nitrogen, ground to a fine powder in a cold mortar, and homogenized in an all-glass mechanical homogenizer. This method provided preparations averaging 43.0 mg of protein per g of mycelium (wet weight). The method was fast, efficient, and did not subject the extract to temperatures above 1 C or to heavy metals. The preparation method was suitable for studying a variety of in vitro fungal enzyme systems. Amylase, acid phosphate dehydrogenase, beta-glucosidase, beta fructofuranosidase, and trehalase activities were measurable in the preparations.
Asunto(s)
Aspergillus , Fraccionamiento Celular/métodos , Fosfatasa Ácida/metabolismo , Fosfatasa Alcalina/metabolismo , Amilasas/metabolismo , Aspergillus/enzimología , Catalasa/metabolismo , Sistema Libre de Células , Ácido Graso Sintasas/metabolismo , Congelación , Glucosafosfato Deshidrogenasa/metabolismo , Glucosidasas/metabolismo , Presión , Sacarasa/metabolismo , Trehalasa/metabolismoRESUMEN
A convenient method is described for the production of up to 1.75 g of citrinin per liter by Penicillium citrinum growing in stationary culture in a 5-gallon (18.925 liters) carboy containing 4 liters of 4% sucrose and 2% yeast extract medium.
Asunto(s)
Antibacterianos/biosíntesis , Medios de Cultivo , Penicillium/metabolismo , Antibacterianos/aislamiento & purificación , Saccharomyces cerevisiae , SacarosaRESUMEN
Virus particles and their component double-stranded ribonucleic acid (dsRNA) have been isolated from conidia and mycelia of certain Penicillium species. The conidia and mycelia of P. stoloniferum NRRL 5267 contained 75 and 85 mug of dsRNA/g (dry weight), respectively. Of the total dsRNA released from NRRL 5267 conidia, 10% was nonencapsulated. Conidia of P. brevi-compactum NRRL 5260 and P. chrysogenum Q-176 contained 2 and 120 mug of dsRNA/g (dry weight), respectively, whereas mycelium from the two species contained 3 and 95 mug of dsRNA/g (dry weight), respectively. No viruses were isolated from conidia or mycelia of P. stoloniferum NRRL 859. A method is described for disruption of both conidia and mycelia. The technique facilitates the isolation and characterization of fungal viruses and their component dsRNA and also potentiates surveying of fungal isolates for the presence of virus.
Asunto(s)
Virus de Plantas/aislamiento & purificación , Virus ARN/aislamiento & purificación , Electroforesis en Gel de Poliacrilamida , Filtros Microporos , Microscopía Electrónica , Penicillium/enzimología , Penicillium/crecimiento & desarrollo , Virus de Plantas/análisis , ARN Viral/análisis , Especificidad de la Especie , Esporas Fúngicas , Trehalasa/metabolismo , UltracentrifugaciónRESUMEN
A rapid technique is described for propagation, harvest, and purification of gram quantities of conidia of five Aspergillus and six Penicillium species.
Asunto(s)
Aspergillus/crecimiento & desarrollo , Penicillium/crecimiento & desarrollo , Pan , Centrifugación , Métodos , Esporas FúngicasRESUMEN
Fifty-two isolates of Penicillium viridicatum Westling were divided into three groups based on ability to produce ochratoxin and/or citrinin, color, growth rate, type of growth, odor, and isolation source. Members of group I resemble one of the representative strains of P. viridicatum described in the literature; those belonging to group II differ from group I strains in several characteristics; group III is a heterogeneous series of highly variable isolates. Although three subgroupings can be recognized, retention of all isolates in the species P. viridicatum is deemed most appropriate at this time. Spore macerates of all isolates were examined for virus-like particles but none were detected.
Asunto(s)
Micotoxinas/biosíntesis , Penicillium/clasificación , Caproatos/biosíntesis , Cromatografía de Gases , Cromatografía en Capa Delgada , Color , Condimentos , Flavonoides/biosíntesis , Harina , Microbiología de Alimentos , Espectrometría de Masas , Ocratoxinas/biosíntesis , Odorantes , Penicillium/crecimiento & desarrollo , Penicillium/aislamiento & purificación , Penicillium/metabolismo , Virus de Plantas/aislamiento & purificación , Esporas Fúngicas/análisis , Triticum , Estados Unidos , Zea maysRESUMEN
The preparation of crystalline ochratoxin A from Aspergillus ochraceus nutrient solution is described. Methods are adaptable to large-scale fermentations.