TL;DR: It is hypothesize that the pairs of strains isolated from O. triphylla root nodules can be co-microsymbionts having complementary sets of symbiotic genes and their simultaneous presence in roots is required for efficient nodulation of the host plant.
Abstract: Four pairs of strains were isolated from four individual root nodules collected from different plants of the Miocene-Pliocene relict legume Oxytropis triphylla growing in the Baikal region (one nodule – one pair of strains). Identification of these strains by the 16S rRNA gene sequencing showed that one strain of each pair was fast-growing and phylogenetically closest to the type strains Phyllobacterium endophyticum PEPV15T (98.8–99.5% 16S rDNA similarity) and Phyllobacterium bourgognense STM 201T (98.8–99.3% 16S rDNA similarity). The other strain was slow-growing and closely related to the type strains Bosea vestrisii 34635T and Bosea eneae 34614T (99.5–99.8% 16S rDNA similarity). Results of the atpD gene sequencing suggested that Phyllobacterium-related isolates most probably belong to a new species of Phyllobacterium. It is known that none of the currently described strains of P. endophyticum, P. bourgognense (family Phyllobacteriaceae), B. vestrisii and B. eneae (family Bradyrhizobiaceae) can ...
TL;DR: After phenotypic, chemotaxonomic and genomic analyses, this isolate was identified as a novel species for which the name Bosea psychrotolerans is proposed.
Abstract: Three strains of a Gram-stain negative bacterium were isolated from Lake Michigan water. 16S rRNA gene sequence analysis revealed that strain 1131 had sequence similarities to
Bosea vaviloviae
LMG 28367T,
Bosea lathyri
LMG 26379T,
Bosea lupini
LMG 26383T,
Bosea eneae
CCUG 43111T,
Bosea vestrisii
CCUG 43114T and
Bosea
massiliensis
CCUG 43117T of 99.8, 99.1, 98.4, 98.4, 98.4 and 98.2 %, respectively. The average nucleotide identity value between strain 1131T and
Bosea vaviloviae
Vaf-18T was 93.4 % and the DNA relatedness was 38 %. The primary cellular fatty acids of strain 1131T were C16 : 1ω7c and C18 : 1ω7c. The primary polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine. The major compound in the quinone system was ubiquinone Q-10 and in the polyamine pattern sym-homospermidine was predominant. Additional phenotypic characteristics included growth at 5–35 °C, pH values of pH 5.5–8.0, a salt tolerance range of 0.0–1.2 % (w/v), and production of an unknown water soluble brown pigment. After phenotypic, chemotaxonomic and genomic analyses, this isolate was identified as a novel species for which the name
Bosea
psychrotolerans is proposed. The type strain is 1131T (NRRL B-65405=LMG 30034).
TL;DR: The novel species of the genus Bosea proposed here form a well-separated cluster in the Bradyrhizobium group of the alpha-2 subclass of the Proteobacteria, on the basis of 16S rDNA gene sequence analysis, which was not sufficient to delineate the species.
Abstract: On the basis of phenotypic and DNA relatedness data, three novel species of the genus Bosea are proposed, Bosea massiliensis (63287T =CIP 106336T =CCUG 43117T), Bosea vestrisii (34635T =CIP 106340T =CCUG 43114T) and Bosea eneae (34614T =CIP 106338T =CCUG 43111T). The original description of the genus Bosea included thiosulphate oxidation as a phenotypic feature, when the sole and type species of the genus, Bosea thiooxidans, was proposed. The three novel species described herein were not able to oxidize thiosulphate; thus, it is proposed that this characteristic be removed from the description of the genus and considered as specific for B. thiooxidans. The novel species of the genus Bosea proposed here form a well-separated cluster in the Bradyrhizobium group of the α-2 subclass of the Proteobacteria, on the basis of 16S rDNA gene sequence analysis. However, 16S rDNA gene sequence analysis was not sufficient to delineate the species; hence, DNA–DNA relatedness and phenotypic data were also required. All of the novel species described in this study are fastidious bacteria isolated from a hospital water supply, using co-cultivation with amoebae. This group of bacteria are hypothesized to be a potential cause of nosocomial infections. For treatment of infections caused by these novel bacteria, doxycycline appears to be the sole antibacterial compound with a consistently low MIC value.