RESUMEN
The taxonomic position of a thermophilic actinomycete strain isolated from poultry faeces was examined using a polyphasic approach. The isolate, designated B19T, was assigned to the genus Streptomyces on the basis of chemotaxonomic and morphological criteria. An almost complete 16S rRNA gene (rDNA) sequence obtained for the test strain was compared with those of representative streptomycetes, notably thermophilic streptomycetes. 16S rDNA sequence data not only supported the assignment of the strain to the genus Streptomyces but also showed that the isolate formed a distinct phyletic line within the evolutionary branch composed of Streptomyces thermodiastaticus and related species. The strain was distinguished from related validly described Streptomyces species by a number of phenotypic properties. It is, therefore, proposed that strain B19T be classified in the genus Streptomyces as Streptomyces thermocoprophilus sp. nov.
Asunto(s)
Celulasa/metabolismo , Streptomyces/clasificación , Xilosidasas/metabolismo , Animales , Composición de Base , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Ácido Diaminopimélico/análisis , Endo-1,4-beta Xilanasas , Heces/microbiología , Datos de Secuencia Molecular , Fenotipo , Filogenia , Aves de Corral , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Streptomyces/química , Streptomyces/enzimología , Streptomyces/fisiologíaRESUMEN
The taxonomic position of a streptomycete strain isolated from Malaysian soil was established using a polyphasic approach. The organism, designated strain ATB-11T, was found to have chemical and morphological properties consistent with its classification in the genus Streptomyces. An almost complete 16S rRNA gene (rDNA) sequence determined for the test strain was compared with those of previously studied streptomycetes by using two treeing algorithms. The 16S rDNA sequence data not only supported classification of the strain in the genus Streptomyces but also showed that it formed a distinct phyletic line. At maturity, the aerial hyphae of strain ATB-11T differentiated into tight, spiral chains of rugose, cylindrical spores. The organism was readily distinguished from representatives of validly described Streptomyces species with rugose spores by using a combination of phenotypic features. It is proposed, therefore, that strain ATB-11T be classified in the genus Streptomyces as Streptomyces malaysiensis sp. nov.
Asunto(s)
Microbiología del Suelo , Streptomyces/clasificación , Streptomyces/genética , Técnicas de Tipificación Bacteriana , ADN Ribosómico/genética , Genes de ARNr , Datos de Secuencia Molecular , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Esporas Bacterianas/fisiología , Streptomyces/química , Streptomyces/fisiologíaRESUMEN
1. A rough inverse correlation between liver serine dehydratase activity and species body size was observed with mammals. This was not found for glutamate, malate or lactate dehydrogenase, fumarase or aspartate-2-oxoglutarate aminotransferase. Serine dehydratase (and certain liver aminotransferases showing a similar species-size dependence) may have a role in the stimulation of heat production. 2. Cold-exposed rats showed a 3-4 fold increase in serine dehydratase activity. 3. No liver serine dehydratase was measurable in amphibia. 4. In mammals high liver serine-pyruvate aminotransferase is associated with a flesh-eating dietary habit. High activity was found in amphibia and goldfish. A gluconeogenic role is suggested.
Asunto(s)
L-Serina Deshidratasa/metabolismo , Hígado/enzimología , Transaminasas/metabolismo , Animales , Peso Corporal , Especificidad de la Especie , VertebradosRESUMEN
Rat liver l-serine-pyruvate aminotransferase activity exceeds markedly the normal adult value (a) in the neonatal period, (b) after glucagon injection and (c) after alloxan injection, observations that reinforce the suggestion from comparative findings that the aminotransferase has a role in gluconeogenesis. Some findings, however, argue in favour of l-serine dehydratase as the enzyme of gluconeogenesis from l-serine.