RESUMO
A thermophilic, anaerobic, chemo-organotrophic bacterium, designated MV1087T, was isolated from a deep-sea hydrothermal chimney sample collected from the Mid-Atlantic Ridge. The cells were straight, motile and stained gram-negative. Growth was observed from 45 to 65 degrees C, with an optimum around 65 degrees C. No growth was observed at 40 or 70 degrees C. Growth was observed from pH 5.5 to 9.0 and the optimum pH was around 7. The salinity range for growth was 10-100 g sea salt l(-1) (corresponding to 6.5-65 g NaCl l(-1)) with an optimum at 30 g sea salt l(-1) (20 g NaCl l(-1)). Strain MV1087T was heterotrophic, able to ferment proteinaceous substrates, such as brain/heart infusion and gluten, and carbohydrates, such as glucose, xylan and starch. The DNA G+C content was 27 mol%. Phylogenetic analyses using 16S rDNA sequences indicated that strain MV1087T belonged to cluster XII of the Clostridium subphylum. Due to its phenotypic and genotypic characteristics, isolate MV1087T is proposed as a novel species of a new genus, Caloranaerobacter azorensis gen. nov., sp. nov. The type strain is MV1087T (= CNCM I-2543T = DSM 13643T).
Assuntos
Bactérias Anaeróbias/classificação , Bactérias Anaeróbias/isolamento & purificação , Água do Mar/microbiologia , Bactérias Anaeróbias/genética , Bactérias Anaeróbias/crescimento & desenvolvimento , Bactérias Anaeróbias/ultraestrutura , Meios de Cultura , DNA Ribossômico/análise , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , TemperaturaRESUMO
A thermophilic, anaerobic, chemo-organotrophic sulfur-reducing bacterium, designated MV1075T, was isolated from a deep-sea hydrothermal chimney sample collected on the Mid-Atlantic Ridge. Cells were rod-shaped with a sheath-like outer structure, motile with polar flagella and stained Gram-negative. They appeared singly, in pairs or in short chains. The temperature range for growth was 25-65 degrees C, with an optimum at 55 degrees C. Growth was observed from pH 5 to pH 9, and the optimum pH was around 7. The salinity range for growth was 15-70 g sea salt l(-1) (corresponding to 10-45 g NaCl l(-1)), with an optimum at 30 g l(-1) (20 g NaCl l(-1)). The isolate was able to grow on a broad spectrum of carbohydrates or complex proteinaceous substrates. Sulfur was not necessary for growth. Growth was inhibited by H2, but, in presence of sulfur, this inhibition was removed and H2S was produced. The G+C content of the genomic DNA was 29 mol %. Phylogenetic analyses of the 16S rRNA gene located the strain within the order Thermotogales, in the domain Bacteria. On the basis of 16S rDNA sequence comparisons, in combination with morphological and physiological characteristics, it is proposed that the isolate should be described as a novel species of a new genus, Marinitoga gen. nov., of which Marinitoga camini sp. nov. is the type species. The type strain is MV1075T (= CNCM 1-2413T = DSM 13578T).
Assuntos
Bacilos Gram-Negativos Anaeróbios Retos, Helicoidais e Curvos/classificação , Temperatura Alta , Água do Mar/microbiologia , Microbiologia da Água , Açores , DNA Ribossômico/genética , Bacilos Gram-Negativos Anaeróbios Retos, Helicoidais e Curvos/isolamento & purificação , Bacilos Gram-Negativos Anaeróbios Retos, Helicoidais e Curvos/ultraestrutura , Testes de Sensibilidade Microbiana , Mid-Atlantic Region , Dados de Sequência Molecular , RNA Ribossômico 16S/genética , Terminologia como AssuntoRESUMO
A deep-sea, facultatively anaerobic, heterotrophic, mesophilic new organism was isolated from the polychaete annelid Alvinella pompejana collected from a deep-sea hydrothermal field in the East Pacific Rise. On the basis of phenotypic characteristics, phylogenetic analyses, and DNA-DNA relatedness, this organism was identified as a new species of the genus Vibrio, for which the name Vibrio diabolicus is proposed. In batch cultures in the presence of glucose, this organism produced an innovative exopolysaccharide. This polymer had high contents of both uronic acids and hexosamines and was similar to other polysaccharides with interesting biological activities.
Assuntos
DNA Bacteriano/análise , Filogenia , Poliquetos/microbiologia , RNA Ribossômico 16S/análise , Vibrio/classificação , Vibrio/genética , Animais , Composição de Bases , Divisão Celular/fisiologia , Concentração de Íons de Hidrogênio , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Cloreto de Sódio , Temperatura , Vibrio/química , Vibrio/fisiologiaRESUMO
A deep-sea, aerobic, mesophilic and heterotrophic new bacterium was isolated from a sample of fluid collected among a dense population of Riftia pachyptila, in the vicinity of an active hydrothermal vent of the Southern depression of the Guaymas basin (Gulf of California). On the basis of phenotypic and phylogenetic analyses and DNA/DNA relatedness, the strain GY785 was recognized as a new species of the genus Alteromonas and the name of Alteromonas infernus is proposed. During the stationary phase in batch cultures in the presence of glucose, this bacterium secreted two unusual polysaccharides. The water-soluble exopolysaccharide-1 produced contained glucose, galactose, galacturonic and glucuronic acids as monosaccharides. The gel-forming exopolysaccharide-2 was separated from the bacterial cells by dialysis against distilled water and partially characterized.
Assuntos
Bactérias Aeróbias Gram-Negativas/isolamento & purificação , Filogenia , Polissacarídeos Bacterianos/biossíntese , Microbiologia da Água , Composição de Bases , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/genética , Glucose/metabolismo , Bactérias Aeróbias Gram-Negativas/genética , Bactérias Aeróbias Gram-Negativas/metabolismo , Dados de Sequência Molecular , Polissacarídeos Bacterianos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Homologia de Sequência do Ácido NucleicoRESUMO
A deep-sea, aerobic, mesophilic, heterotrophic bacterium was isolated from fluid collected near an active hydrothermal vent. On the basis of phenotypic and phylogenetic analyses and DNA-DNA relatedness, strain ST716 could be assigned to the species Alteromonas macleodii as a new subspecies. This bacterium secreted an unusual high-molecular-weight polysaccharide in the presence of glucose in batch cultures. The viscosity of this exopolysaccharide is of the same order of magnitude as that of xanthan, another bacterial polysaccharide of industrial interest. This polysaccharide, produced during the stationary phase, contained glucose, mannose, pyruvated mannose, and galactose along with galacturonic acid and glucuronic acid.
Assuntos
Bactérias Aeróbias Gram-Negativas/genética , Bactérias Aeróbias Gram-Negativas/metabolismo , Polímeros/metabolismo , Polissacarídeos Bacterianos/metabolismo , Microbiologia da Água , Composição de Bases , DNA Bacteriano/genética , Glucuronatos/análise , Ácido Glucurônico , Bactérias Aeróbias Gram-Negativas/isolamento & purificação , Hexoses/análise , Ácidos Hexurônicos/análise , Dados de Sequência Molecular , Peso Molecular , Filogenia , Polímeros/química , Polissacarídeos Bacterianos/química , RNA Ribossômico 16S/genética , Água do Mar , Alinhamento de Sequência , Análise de Sequência de DNARESUMO
The heterotrophic and mesophilic marine bacterium HYD-1545 was isolated on a metal-amended medium from the dorsal integument of the hydrothermal vent polychaete Alvinella pompejana. This strain, which can be assigned to the genus Alteromonas on the basis of its G+C content and phenotypical features, produced large amounts of an acidic polysaccharide in batch cultures. The polysaccharide was excreted during the stationary phase of growth and contained glucose, galactose, glucuronic acid, galacturonic acid, and 4,6-O-(1-carboxyethilidene)-galactose as major components. This polysaccharide was a polyelectrolyte, and the viscosity of its solutions depended on the ionic strength. The decrease in viscosity with increasing NaCl concentrations and the effect of Ca in decreasing the viscosity at low Ca concentrations support a model in which the polysaccharide carries anionic groups. However, an unusual behavior was observed at higher concentrations and could be related to intermolecular interactions involving Ca ions.