RESUMEN
DNA-DNA reassociation studies, 16S rRNA gene sequence comparisons and fatty acid analysis were used to reassess the taxonomic status of the type strain of Rhodothermus obamensis and several strains of the genus Rhodothermus isolated from widely distributed shallow marine hot springs. The results show that the type strain of R. obamensis, JCM 9785T, has a DNA-DNA reassociation value of 78% with the type strain of R. marinus, DSM 4252T. The other strains examined had DNA-DNA reassociation values that varied between about 68 and 94% with R. marinus. The 165 rRNA gene sequence was determined for the type strain of R. obamensis and found to share 99.5% similarity with the type strain of R. marinus. The fatty acid composition of R. obamensis was slightly different from that of the other strains examined, but indicated that this strain is very closely related to the other strains examined in this study. On the basis of DNA-DNA reassociation values, 16S rRNA gene sequence comparison and fatty acid profiles, it was concluded that R. obamensis and R. marinus represent the same species and that the name Rhodothermus obamensis should be regarded as a junior synonym of Rhodothermus marinus.
Asunto(s)
Bacterias Aerobias Gramnegativas/clasificación , Microbiología del Agua , Clonación Molecular , ADN Bacteriano/genética , ADN Ribosómico/genética , Ácidos Grasos/análisis , Bacterias Aerobias Gramnegativas/química , Bacterias Aerobias Gramnegativas/genética , ARN Bacteriano/análisis , ARN Ribosómico 16S/análisis , TemperaturaRESUMEN
Several yellow-pigmented isolates, with optimum growth temperatures of about 65-70 degrees C, were recovered from hot springs in Iceland. Phylogenetic analysis of the 16S rDNA and DNA-DNA reassociation values showed that these organisms represented two new species of the genus Thermus. Strains RF-4T and HN1-8 had maximum temperatures for growth below 80 degrees C, while strains HN3-7T and HN2-7, unlike all other strains of the species of the genus Thermus except those belonging to Thermus thermophilus, grew at 80 degrees C. The new isolates from Iceland could not be distinguished easily from each other or from other strains of the species of the genus Thermus by biochemical characteristics; however, strains RF-4T and HN1-8 assimilated ribitol, a characteristic which was not detected in any of the other strains examined. Moreover, the species represented by strains RF-4T and HN1-8 and the species represented by strains HN3-7T and HN2-7 could be distinguished clearly from the other species of Thermus by their fatty acid composition. Strains RF-4T and HN1-8 have the highest combined levels of iso-15:0 and iso-17:0 and the lowest levels of iso-16:0 of any of the strains of the species of Thermus, while strains HN3-7T and HN2-7 are characterized by a very low iso-15:0/iso-17:0 ratio. On the basis of the phylogenetic analysis, DNA-DNA reassociation values, physiological and biochemical characteristics and fatty acid composition, the name Thermus igniterrae sp. nov. is proposed for the species represented by strains RF-4T and HN1-8 and the name Thermus antranikianii sp. nov. is proposed for the species represented by strains HN3-7T and HN2-7.
Asunto(s)
Thermus/clasificación , Microbiología del Agua , Composición de Base , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Ácidos Grasos/análisis , Genes de ARNr , Concentración de Iones de Hidrógeno , Islandia , Lípidos/análisis , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Filogenia , Pigmentación , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Temperatura , Thermus/química , Thermus/genética , Thermus/crecimiento & desarrollo , Thermus/aislamiento & purificaciónRESUMEN
Several acidophilic, slightly thermophilic or thermophilic Gram-positive isolates were recovered from solfataric soil at Furnas on the Island of São Miguel in the Azores. Phylogenetic analysis of the 16S rRNA gene sequence showed that these organisms represented two novel species of the genus Alicyclobacillus. Strains FR-11T and FR-1b had an optimum growth temperature of about 50 degrees C, whereas strains FR-3 and FR-6T had an optimum growth temperature of about 60 degrees C. Biochemical, physiological and chemotaxonomic characteristics did not distinguish isolates FR-3 and FR-6T from the type strain of Alicyclobacillus acidocaldarius; however, strains FR-11T and FR-1b could be easily distinguished from the type strain of Alicyclobacillus acidoterrestris by the carbon source assimilation pattern and the fatty acid composition. On the basis of the phylogenetic analysis, physiological and biochemical characteristics, and fatty acid composition the name Alicyclobacillus hesperidum is proposed for the species represented by strains FR-11T and FR-1b; a formal name for the new genomic species represented by strains FR-3 and FR-6T is not proposed at this time.
Asunto(s)
Bacilos Grampositivos Formadores de Endosporas/clasificación , Bacilos Grampositivos Formadores de Endosporas/aislamiento & purificación , Microbiología del Suelo , Azores , Técnicas de Tipificación Bacteriana , Ácidos Grasos/análisis , Genes de ARNr , Bacilos Grampositivos Formadores de Endosporas/genética , Bacilos Grampositivos Formadores de Endosporas/fisiología , Lípidos/análisis , Datos de Secuencia Molecular , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , TemperaturaRESUMEN
Strains of Deinococcus geothermalis sp. nov. were isolated from the hot spring and runoff at Agnano, Naples, Italy, and from the hot spring at São Pedro do Sul in central Portugal, while strains of Deinococcus murrayi sp. nov. were isolated from the hot springs at São Pedro do Sul, São Gemil, and Alcafache in central Portugal. The strains of D. geothermalis and D. murrayi produce orange-pigmented colonies and have an optimum growth temperature of about 45 to 50 degrees C. The type strains of the two new species are extremely gamma radiation resistant. The fatty acids of these new species are primarily branched-chain fatty acids. The two new species can be distinguished from each other by the lower pH range of D. geothermalis than of D. murrayi, by their fatty acid compositions, and by several biochemical parameters, including the ability of D. geothermalis to grow in minimal medium without yeast extract. 16S rRNA gene sequencing also showed that the isolates constitute two species and that these species are distinct from the other species of the genus Deinococcus. The type strain of D. geothermalis is AG-3a (= DSM 11300), and the type strain of D. murrayi is ALT-1b (= DSM 11303).
Asunto(s)
ADN Bacteriano/análisis , Cocos Grampositivos/clasificación , Cocos Grampositivos/genética , Filogenia , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Composición de Base , Genes Bacterianos/genética , Glucosa/análisis , Cocos Grampositivos/química , Cocos Grampositivos/crecimiento & desarrollo , Cocos Grampositivos/ultraestructura , Concentración de Iones de Hidrógeno , Lípidos/análisis , Microscopía Electrónica , Datos de Secuencia Molecular , Tolerancia a Radiación , TemperaturaRESUMEN
Strains of Meiothermus cerbereus sp. nov. were isolated from the hot springs within the Geysir geothermal area of Iceland. The strains of Meiothermus cerbereus produce red-orange-pigmented colonies, have an optimum growth temperature of about 55 degrees C, and have higher levels of 3-OH fatty acids than the strains of the other species of the genus Meiothermus. These strains, unlike all other strains of the species of the genus Meiothermus examined previously, required cysteine, thiosulfate, or thioglycolate for growth in liquid Thermus medium, but not in the corresponding medium solidified with agar. Several strains belonging to Meiothermus silvanus, isolated from Geysir, also required reduced sulfur compounds for growth in liquid medium, leading to the hypothesis that this requirement is not a taxonomic characteristic of the new species. The new species represented by strains GY-1T and GY-5 can be distinguished from the other species of the genus Meiothermus by biochemical characteristics, fatty acid composition, DNA-DNA reassociation values, and 16S ribosomal DNA sequence. The type strain for Meiothermus cerbereus is GY-1 (= DSM 11376).
Asunto(s)
Ácidos Grasos/análisis , Thermus/química , Thermus/clasificación , Composición de Base , Medios de Cultivo/metabolismo , ADN Bacteriano/análisis , Lípidos/análisis , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Filogenia , ARN Ribosómico 16S/análisis , Thermus/genética , Thermus/crecimiento & desarrollo , Thermus/metabolismoRESUMEN
OBJECTIVE: To determine relation between schoolchildren's blood pressure, glycated haemoglobin level, and cholesterol concentration and their anthropometry, socioeconomic status, and birth measurements. DESIGN: Retrospective cohort study. SETTING: 27 schools closest to University Hospital of the West Indies, Kingston, Jamaica. SUBJECTS: 2337 children aged 6-16 years who were born at university hospital were recruited, and their birth records were recovered: 1610 had suitable records, 659 had records including birth length, and 610 of these were prepubertal. MAIN OUTCOME MEASURES: Blood pressure, glycated haemoglobin level, serum cholesterol concentration, anthropometry at birth, current anthropometry, and socioeconomic status. RESULTS: Multiple regression analysis showed that children's systolic blood pressure was inversely related to their birth weight (P < 0.0001) and directly related to their current weight. Glycated haemoglobin level was higher in children with thicker triceps skinfolds (P < 0.001) and who had been shorter at birth (P = 0.003). Serum cholesterol concentration was inversely related to current height (P = 0.001) and to length at birth (P = 0.09) and was directly related to triceps skinfold thickness and higher socioeconomic status (P < 0.001). CONCLUSIONS: Blood pressure in childhood was inversely related to birth weight and directly to current weight. Glycaemic control and serum cholesterol were related to short length at birth, height deficit in childhood, and childhood obesity.