RESUMO
A study was conducted to determine the taxonomic status of six actinomycete strains isolated from root nodules of Lupinus angustifolius. The strains were filamentous, Gram-positive and produced single spores at the tip of the hyphae. Phylogenetic, chemotaxonomic and morphological analyses demonstrated that all six strains belonged to the genus Micromonospora. According to the 16S rRNA gene sequence data, the strains were divided into two clusters that are moderately related to Micromonospora mirobrigensis, Micromonospora matsumotoense and Micromonospora purpureochromogenes. Fatty acid patterns also supported the division of the strains, and significant differences between the two groups were found in the amounts of iso-15 : 0, iso-16 : 0, iso-16 : 1 and iso-17 : 0. Furthermore, the two groups showed physiological differences which included utilization of arabinose, trehalose, alanine and sucrose and xylan hydrolysis. Finally, DNA-DNA hybridization and ribotyping studies confirmed that each group represents a novel species. Based on the genotypic and phenotypic data, the novel species Micromonospora lupini sp. nov. (type strain Lupac 14N(T) =DSM 44874(T) =LMG 24055(T)) and Micromonospora saelicesensis sp. nov. (type strain Lupac 09(T) =DSM 44871(T) =LMG 24056(T)) are proposed.
Assuntos
Lupinus/microbiologia , Micromonospora/classificação , Micromonospora/isolamento & purificação , Raízes de Plantas/microbiologia , Alanina/metabolismo , Técnicas de Tipagem Bacteriana , Metabolismo dos Carboidratos , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Ácidos Graxos/análise , Genes de RNAr , Micromonospora/química , Micromonospora/genética , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Filogenia , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Ribotipagem , Homologia de Sequência do Ácido Nucleico , Esporos Bacterianos/citologiaRESUMO
An actinomycete strain was recovered from a pond where radon is known to be dissolved. A polyphasic study was undertaken to identify the new isolate. The 16S rRNA gene sequence of strain WA201(T) showed closest similarity to the type strains of Micromonospora carbonacea (98.5 %) and Micromonospora matsumotoense (98.1 %). The chemotaxonomic results confirmed the taxonomic position of the isolate in the genus Micromonospora. DNA-DNA relatedness values supported the classification of this isolate as a novel species. A number of physiological and biochemical tests were able to distinguish strain WA201(T) from its closest phylogenetic neighbours. Therefore, it is proposed that isolate WA201(T) (=DSM 44830(T)=LMG 22229(T)) be considered the type strain representing a novel species, Micromonospora mirobrigensis sp. nov.