RESUMEN
Three pink-pigmented, aerobic, Gram-stain-negative, rod-shaped and facultatively methylotrophic strains were isolated from the phyllosphere of Trifolium repens and Cerastium holosteoides. 16S rRNA gene sequence analysis support the affiliation of all strains to the genus Methylobacterium. The closest relatives of strains C34(T) and T5 were Methylobacterium gnaphalii 23e(T) (98.0 and 98.5 % sequence similarity, respectively) and Methylobacterium organophilum JCM 2833(T) (97.0 and 97.2 %, respectively). Strain TA73(T) showed the highest sequence similarities to Methylobacterium marchantiae JT1(T) and Methylobacterium bullatum F3.2(T) (both 97.9 %), followed by Methylobacterium phyllosphaerae CBMB27(T) and Methylobacterium brachiatum DSM 19569(T) (both 97.8 %), Methylobacterium cerastii C15(T) and Methylobacterium radiotolerans JCM 2831(T) (both 97.7 %). The major components in the fatty acid profiles were C18 : 1ω7c, C16 : 0 and one unknown fatty acid for strain TA73(T) and C18 : 1ω7c, C16 : 1ω7c/iso-C15 : 0 2-OH, C18 : 0 and C16 : 0 for strains C34(T) and T5. Physiological and biochemical analysis, including DNA-DNA hybridization, revealed clear differences between the investigated strains and their closest phylogenetic neighbours. DNA-DNA hybridization studies also showed high similarities between strains C34(T) and T5 (59.6-100 %). Therefore, the isolates represent two novel species within the genus Methylobacterium, for which the names Methylobacterium trifolii sp. nov. (type strain TA73(T) = LMG 25778(T) = CCM 7786(T)) and Methylobacterium thuringiense sp. nov. (type strain C34(T) = LMG 25777(T) = CCM 7787(T)) are proposed.
Asunto(s)
Caryophyllaceae/microbiología , Metanol/metabolismo , Methylobacterium/clasificación , Filogenia , Pigmentación , Trifolium/microbiología , Técnicas de Tipificación Bacteriana , ADN Bacteriano/genética , Ácidos Grasos/análisis , Alemania , Methylobacterium/genética , Methylobacterium/aislamiento & purificación , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Hojas de la Planta/microbiología , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNRESUMEN
Two Gram-positive, non-endospore-forming rods, strains C5(T) and T8(T), were isolated from the phyllospheres of Cerastium holosteoides and Trifolium repens, respectively, and were studied in detail for their taxonomic position. 16S rRNA gene sequence analysis allocated both isolates clearly to the genus Rhodococcus. Isolate C5(T) was most closely related to Rhodococcus fascians and Rhodococcus yunnanensis, showing 99.2â% gene sequence similarity to both species. Strain T8(T) revealed the highest 16S rRNA gene sequence similarity to Rhodococcus corynebacterioides (98.8â%) and Rhodococcus kroppenstedtii (98.6â%). The quinone system of both strains was composed of dihydrogenated menaquinones with eight (major amount) as well as nine, seven and six isoprenoid units (MK-8H2, MK-9H2 MK-7H2 MK-6H2).The polar lipid profiles of strains C5(T) and T8(T) consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside and one unknown phospholipid. Additionally, strain C5(T) contained one unknown glycolipid, and strain T8(T) three unknown aminolipids. The fatty acid profiles contained major amounts of C16â:â0, C18â:â1ω9c and 10-methyl C18â:â0, which supported the grouping of the two isolates in the genus Rhodococcus. Physiological/biochemical characterization and DNA-DNA hybridizations with the type strains of the most closely related species allowed a clear phenotypic and genotypic differentiation of both strains. For this reason, we propose strain C5(T) (â=âLMG 26203(T) â=âCCM 7906(T)) as the type strain of a novel species with the name Rhodococcus cerastii sp. nov., and strain T8(T) (â=âLMG 26204(T) â=âCCM 7905(T)) as the type strain of a second novel species with the name Rhodococcus trifolii sp. nov.
Asunto(s)
Filogenia , Hojas de la Planta/microbiología , Rhodococcus/clasificación , Técnicas de Tipificación Bacteriana , Caryophyllaceae/microbiología , ADN Bacteriano/genética , Ácidos Grasos/análisis , Alemania , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Fosfolípidos/análisis , Quinonas/análisis , ARN Ribosómico 16S/genética , Rhodococcus/genética , Rhodococcus/aislamiento & purificación , Análisis de Secuencia de ADN , Trifolium/microbiologíaRESUMEN
Two Gram-stain-negative, non-endospore-forming, rod-like strains, designated C15T and C44, were isolated from the phyllosphere of Cerastium holosteoides and were studied in detail in order to assess their taxonomic position. 16S rRNA gene sequence analysis allocated both isolates clearly to the genus Methylobacterium. Both strains showed the highest 16S rRNA gene sequence similarity to Methylobacterium marchantiae JT1T (97.5â%) and Methylobacterium jeotgali S2R03-9T (97.4â%). The fatty acid profiles contained major amounts of C16:0, C18:1ω7c and C16:1ω7c/iso-C15:0 2-OH (summed feature 3), which supported the grouping of the isolates in the genus Methylobacterium. Physiological/biochemical characterization and DNA-DNA hybridizations with the type strains of the most closely related species allowed a clear phenotypic and genotypic differentiation of the strains. For this reason, we propose for strain C15T (=DSM 23679T=CCUG 60040T=CCM 7788T) a novel species with the name Methylobacterium cerastii sp. nov. Strain C44 (=DSM 23675=CCM 7789) is an additional strain of M. cerastii.
Asunto(s)
Caryophyllaceae/microbiología , Methylobacterium/clasificación , Filogenia , Hojas de la Planta/microbiología , Técnicas de Tipificación Bacteriana , ADN Bacteriano/genética , Ácidos Grasos/química , Genotipo , Alemania , Methylobacterium/genética , Methylobacterium/aislamiento & purificación , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Pigmentación , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNRESUMEN
On the basis of cultivation-dependent (isolation on mineral salt medium supplemented with 0.5% methanol) and -independent (DGGE analysis) methods, we investigated the influence of the host plant species Trifolium repens and Cerastium holosteoides, three geographic locations and the land-use types meadow, mown pasture and pasture on the abundance and community composition of selected phyllosphere bacteria with emphasis on Methylobacterium species. Methylobacterium abundance was significantly higher on leaves of T. repens (mean value 2.0×10(7) CFU PPFM per g leaf) than on leaves of C. holosteoides (mean value 2.0×10(6) CFU per g leaf). Leaves from the sampling site Schorfheide-Chorin showed slightly lower Methylobacterium numbers than leaves of the other sampling sites. Land-use and sampling period had no consistent influence on Methylobacterium community size. Methylobacterium community composition was very similar over both sampling periods, all three sampling sites, all land-use types and both plant species. Moreover, no relationship between geographic and genetic distance was observed. Community composition of selected Proteobacteria was influenced by plant species, geographic location and land-use. Often, differences in community composition could be observed between meadows, mown pastures and pastures but not between different kinds of meadows (cutted once versus three times) and mown pastures (fertilized versus non-fertilized). The results also indicate, that whether there are differences between land-use types or not strongly depends on the investigated host plant species and ecosystem. Besides Methylobacterium, representatives of Methylophilus were detected. The results indicate that Methylobacterium species are generally abundant and stable members of the phyllosphere community whereas other genera occur more occasionally, and that Methylobacterium clearly dominates the methylotrophic phyllosphere community.
Asunto(s)
Bacterias , Methylobacterium , Hojas de la Planta/microbiología , Microbiología del Suelo , Trifolium/microbiología , Bacterias/clasificación , Bacterias/genética , Medios de Cultivo , Ecosistema , Electroforesis , Alemania , Methylobacterium/clasificación , Methylobacterium/genética , Methylobacterium/aislamiento & purificación , Datos de Secuencia Molecular , Plantas/microbiología , Análisis de Secuencia de ADN , Especificidad de la EspecieRESUMEN
A Gram-positive-staining, non-endospore-forming actinobacterium, designated C7(T), was isolated from the leaf surface of Trifolium repens. On the basis of 16S rRNA gene sequence analysis, strain C7(T) was shown to belong to the genus Williamsia and was most closely related to Williamsia maris SJS0289/JS1(T) (98.0 % 16S rRNA gene sequence similarity), Williamsia deligens IMMIB RIV-956(T) (96.4 %) and Williamsia serinedens IMMIB SR-4(T) (95.7 %). The quinone system consisted predominantly of the menaquinones MK-9(H(2)), MK-8(H(2)) and MK-7(H(2)). The major components in the polar lipid profile were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylinositol. Mycolic acids were present. These chemotaxonomic traits and the major fatty acids, which were C(16 : 1)ω7c, C(16 : 0), C(18 : 0), C(18 : 1)ω9c and tuberculostearic acid, supported the affiliation of strain C7(T) with the genus Williamsia. Physiological and biochemical analysis revealed clear differences between strain C7(T) and its closest phylogenetic neighbours. Therefore, strain C7(T) represents a novel species, for which the name Williamsia phyllosphaerae sp. nov. is proposed. The type strain is C7(T) ( = CCUG 60465(T) = CCM 7855(T)).
Asunto(s)
Actinomycetales/clasificación , Actinomycetales/aislamiento & purificación , Hojas de la Planta/microbiología , Trifolium/microbiología , Actinomycetales/genética , Actinomycetales/metabolismo , ADN Bacteriano/genética , Ácidos Grasos/metabolismo , Datos de Secuencia Molecular , Filogenia , ARN Ribosómico 16S/genéticaRESUMEN
A pink-pigmented, facultatively methylotrophic bacterium, designated strain JT1(T), was isolated from a thallus of the liverwort Marchantia polymorpha L. and was analysed by using a polyphasic approach. Comparative 16S rRNA gene sequence analysis placed the strain in a clade with Methylobacterium adhaesivum AR27(T), Methylobacterium fujisawaense DSM 5686(T), Methylobacterium radiotolerans JCM 2831(T) and Methylobacterium jeotgali S2R03-9(T), with which it showed sequence similarities of 97.8, 97.7, 97.2 and 97.4â%, respectively. However, levels of DNA-DNA relatedness between strain JT1(T) and these and the type strains of other closely related species were lower than 70â%. Cells of JT1(T) stained Gram-negative and were motile, rod-shaped and characterized by numerous fimbriae-like appendages on the outer surface of their wall (density up to 200 µm(-2)). Major fatty acids were C(18â:â1)ω7c and C(16â:â0). Based on the morphological, physiological and biochemical data presented, strain JT1(T) is considered to represent a novel species of the genus Methylobacterium, for which the name Methylobacterium marchantiae sp. nov. is proposed. The type strain is JT1(T) (â=âDSM 21328(T) â=âCCUG 56108(T)).