RESUMO
Strains of hyperthermophilic anaerobic hydrothermal vent archaea maintained in the culture collection assembled by Holger Jannasch at the Woods Hole Oceanographic Institution between 1984 and 1998 were identified and partially characterized by Denaturing Gradient Gel Electrophoresis, 16S rRNA gene sequencing, and by growth tests at different temperatures and on different organic carbon and nitrogen sources. All strains were members of the genera Thermococcus and Pyrococcus. The greatest phylogenetic diversity was found in strains from a single Guaymas Basin core isolated by serial dilution from four different depth horizons of heated sediment incubated at the corresponding in situ temperatures. In contrast, geographically distinct vent locations and sample materials yielded a lower diversity of isolates when enriched under uniform temperature regimes and without prior dilution of the source material.
Assuntos
Sedimentos Geológicos/microbiologia , Fontes Termais/microbiologia , Pyrococcus/isolamento & purificação , Thermococcus/isolamento & purificação , Técnicas Bacteriológicas , Meios de Cultura , DNA Bacteriano/genética , Biologia Marinha , México , Dados de Sequência Molecular , Filogenia , Pyrococcus/classificação , Pyrococcus/genética , Pyrococcus/crescimento & desenvolvimento , Pyrococcus/metabolismo , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Ribotipagem , Especificidade da Espécie , Temperatura , Thermococcus/classificação , Thermococcus/genética , Thermococcus/crescimento & desenvolvimento , Thermococcus/metabolismoRESUMO
Growth medium components and cultivation conditions for the extremely thermophilic Archaea Thermococcus celer and Pyrococcus woesei were optimized. A culture media based in marine water was formulated. Both Archaea demonstrated to be strictly anaerobic with optimal growth temperature of 85 degrees and 95 degrees C, respectively. Sodium sulfide, but not cysteine, was used as a sulfur and reductive capacity source. It was observed that hydrogen sulfide could be replaced by 30 microM titanium (III) nitrile acetate. The addition of elemental S(o) enhanced growth of both microorganisms, with T. celer far more sensitive than P. woesei to the absence of S(o). P. woesei utilized maltose as a carbon source, while T. celer was able to use only peptides from yeast extract, peptone and tryptone as its carbon source. Optimum carbon source concentrations were 1.25 g/L for T. celer and 5 g/L for P. woesei. Although both Archaea required peptides as a nitrogen source, the addition of ammonia chloride to a nitrogen-limited media did not stimulate growth, which suggests that neither Archaea appear to metabolize ammonia. The growth of P. woesei, but not T. celer, was stimulated considerably in the presence of iron. Co, Ni, Zn, Mo. Mn and Mg were essential trace elements needed for optimal growth of both bacteria.