RESUMEN
A lactate dehydrogenase, specific for nicotinamide-adenine dinucleotide and D(-)-lactate, has been detected in extracts from two fungi of the order Leptomitales (Oomycetes). Several fungi of this order carry out a lactic acid fermentation under conditions of reduced oxygen tension.
Asunto(s)
Hongos/enzimología , L-Lactato Deshidrogenasa , Fenómenos Químicos , Química , Electroforesis , Técnicas In Vitro , Lactatos , NAD , PiruvatosRESUMEN
The uniflagellate aquatic phycomycete Blastocladia ramosa appears to be a facultative anaerobe. Blastocladia pringsheimii requires traces of oxygen. Growth of both species is no greater or only slightly greater at normal atmospheric oxygen pressure than under 0.2 percent oxygen pressure, but their growth is enhanced by the addition of 5 or 20 percent carbon dioxide. The cells of both species lack typical cristate mitochondria and contain only traces of cytochrome. Blastocladia resembles the biflagellate Aqualinderella fermentans in adaptation to an environment poor in oxygen and rich in carbon dioxide.
Asunto(s)
Cianuros/farmacología , Hongos/metabolismo , Consumo de Oxígeno/efectos de los fármacos , Antimicina A/farmacología , Medios de Cultivo , Farmacorresistencia Microbiana , Transporte de Electrón/efectos de los fármacos , Hongos/efectos de los fármacos , Glucosa/metabolismo , Ácidos Hidroxámicos/farmacología , Factores de TiempoAsunto(s)
Oxidorreductasas de Alcohol/metabolismo , Hongos/enzimología , Sistema Libre de Células , Medios de Cultivo , Etanol/biosíntesis , Fermentación , Hongos/clasificación , Hongos/crecimiento & desarrollo , Hongos/metabolismo , Glucosa/metabolismo , NAD/metabolismo , Especificidad de la Especie , Espectrofotometría , TemperaturaAsunto(s)
Hongos/enzimología , L-Lactato Deshidrogenasa/análisis , Sistema Libre de Células , Electroforesis en Gel de Almidón , Isoenzimas , L-Lactato Deshidrogenasa/metabolismo , NAD/metabolismo , NADP/metabolismo , Ácidos Nicotínicos/metabolismo , Piridinas/metabolismo , Espectrofotometría , TemperaturaAsunto(s)
Oxidorreductasas de Alcohol/análisis , Hongos/enzimología , Rhizopus/enzimología , Oxidorreductasas de Alcohol/metabolismo , Sistema Libre de Células , Estabilidad de Medicamentos , Etanol/metabolismo , Concentración de Iones de Hidrógeno , NAD/metabolismo , Oxidación-Reducción , Especificidad de la Especie , Espectrofotometría , TemperaturaRESUMEN
The electron transport systems of 2 species of aquatic fungi, Leptomitus lacteus and A podachlya punctata, contained cytochrome a-a(3) (605 mmu), 2 b type cytochromes (564 and 557 mmu), c type cytochrome (551 mmu), and flavoprotein, but they appeared to lack cytochrome c(1). Reduced-minus-oxidized difference spectra and difference spectra in the presence of antimycin A or cyanide were used to characterize these systems. Studies with the electron microscope revealed that hyphae of Leptomitus lacteus contained numerous, conspicuous mitochondria with tubular cristae.
RESUMEN
The cytochrome systems of two classes of aquatic fungi, the Oomycetes and Chytridiomycetes, were studied by means of reduced-minus-oxidized difference spectra at room and at low temperature. At room temperature, all of these fungi have a c-type cytochrome with an absorption maximum at 551 mmu and a b-type cytochrome at 564 mmu. The Oomycetes have a-type cytochromes at 605 mmu, and the Chytridiomycetes have a-type cytochromes at 606 mmu (Blastocladiales) or at 609 mmu (Monoblepharidales). Additional b-type cytochromes are found at 557 mmu in the Oomycetes and at approximately 560 mmu in the Chytridiomycetes. The data obtained from spectra at low temperature are consistent with these conclusions. Thus, the difference spectra reveal variation between the cytochrome systems of these two classes of aquatic fungi.
Asunto(s)
Citocromos/análisis , Microbiología del Agua , Hongos/análisis , TemperaturaRESUMEN
A glutamate dehydrogenase specific for nicotinamide-adenine-dinucleotide has been purified 50-fold from Apodachlya brachynema (Leptomitales). Certain physical, chemical, and kinetic properties of this enzyme have been studied, particularly specificity for coenzymes and substrates. With glucose as the sole carbon source, the synthesis of glutamate dehydrogenase was repressed, whereas glutamate, proline, alanine, or ornithine plus aspartate as sole carbon sources induced synthesis of the enzyme. These data indicate that the function of this enzyme is primarily degradative, although there is no evidence for a nicotinamide-adenine-dinucleotide-phosphate-specific biosynthetic glutamate dehydrogenase in Apodachlya.