RESUMO
Three novel bacterial strains, PVAS-1(T), B3W22(T) and B8W22(T), were isolated from cryotubes used to collect air samples at altitudes of between 27 and 41 km. Based on phenotypic characteristics, chemotaxonomic features, DNA-DNA hybridization with the nearest phylogenetic neighbours and phylogenetic analysis based on partial 16S rRNA gene sequences (PVAS-1(T), 1196 nt; B3W22(T), 1541 nt; B8W22(T), 1533 nt), the three strains were identified as representing novel species, and the names proposed are Janibacter hoylei sp. nov. (type strain PVAS-1(T) =MTCC 8307(T) =DSM 21601(T) =CCUG 56714(T)), Bacillus isronensis sp. nov. (type strain B3W22(T) =MTCC 7902(T) =JCM 13838(T)) and Bacillus aryabhattai sp. nov. (type strain B8W22(T) =MTCC 7755(T) =JCM 13839(T)).
Assuntos
Actinomycetales/classificação , Actinomycetales/isolamento & purificação , Microbiologia do Ar , Ar/análise , Bacillus/isolamento & purificação , Equipamentos e Provisões/microbiologia , Actinomycetales/genética , Bacillus/classificação , Bacillus/genética , DNA Bacteriano/genética , DNA Ribossômico/genética , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/genéticaRESUMO
Four novel bacterial strains were isolated from cryogenic tubes used to collect air samples at altitudes of 24, 28 and 41 km. The four strains, 24K(T), 28K(T), 41KF2a(T) and 41KF2b(T), were identified as members of the genus Bacillus. Phylogenetic analysis based on 16S rRNA gene sequences indicated that three of the strains, 24K(T), 28K(T) and 41KF2a(T), are very similar to one another (>98 % sequence similarity) and show a similarity of 98-99 % with Bacillus licheniformis and 98 % with Bacillus sonorensis. DNA-DNA hybridization studies showed that strains 24K(T), 28K(T) and 41KF2a(T) exhibit <70 % similarity with each other and with B. licheniformis and B. sonorensis. Differences in phenotypic and chemotaxonomic characteristics between the novel strains and B. licheniformis and B. sonorensis further confirmed that these three isolates are representatives of three separate novel species. Strain 41KF2b(T) showed 100 % 16S rRNA gene sequence similarity to Bacillus pumilus, but differed from its nearest phylogenetic neighbour in a number of phenotypic and chemotaxonomic characteristics and showed only 55 % DNA-DNA relatedness. Therefore, the four isolates represent four novel species for which the names Bacillus aerius sp. nov. (type strain, 24K(T)=MTCC 7303(T)=JCM 13348(T)), Bacillus aerophilus sp. nov. (type strain, 28K(T)=MTCC 7304(T)=JCM 13347(T)), Bacillus stratosphericus sp. nov. (type strain, 41KF2a(T)=MTCC 7305(T)=JCM 13349(T)) and Bacillus altitudinis sp. nov. (type strain, 41KF2b(T)=MTCC 7306(T)=JCM 13350(T)) are proposed.
Assuntos
Microbiologia do Ar , Altitude , Bacillus/classificação , Bacillus/isolamento & purificação , Antibacterianos/farmacologia , Bacillus/química , Bacillus/genética , Bacillus/fisiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , Temperatura Baixa , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Ácidos Graxos/análise , Ácidos Graxos/isolamento & purificação , Genes de RNAr/genética , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Filogenia , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNARESUMO
Samples of air removed from the stratosphere, at an altitude of 41 km, were previously found to contain viable, but non-cultureable bacteria (cocci and rods). Here, we describe experiments aimed at growing these, together with any other organisms, present in these samples. Two bacteria (Bacillus simplex and Staphylococcus pasteuri) and a single fungus, Engyodontium album (Limber) de Hoog were isolated from the samples. Although the possibility of contamination can never be ruled out when space-derived samples are studied on earth, we are confident that the organisms originated from the stratosphere. Possible mechanisms by which these organisms could have attained such a height are discussed.
Assuntos
Atmosfera , Bacillus/isolamento & purificação , Meio Ambiente Extraterreno , Staphylococcus/isolamento & purificação , Altitude , Bacillus/classificação , Meio Ambiente , Fungos/isolamento & purificação , Filogenia , Staphylococcus/classificaçãoRESUMO
Biscalar and bivector Green's functions of wave equations are calculated explicitly in de Sitter space time. The calculation is performed by considering the electromagnetic field generated by the spontaneous creation of an electric charge.
