We report the whole-genome sequence of the non-rhizobial endosymbiotic bacteria Tardiphaga sp. strain 709, which was isolated from the root nodule of Astragalus inopinatus Borris. on the Kamchatka Peninsula, Russia. The genome consists of one chromosome and one plasmid with a total length of 6,359,564 bp and 61.5% of GC content.

The field studies of rhizobial inoculants require using simple and reliable methods for identification of the strains used to find out exactly which strain has formed a nitrogen-fixing nodule. This problem appears when testing the competitive ability of inoculant strains with respect to the local rhizobial strains, in order to follow the fate of inoculant strains in the long-term periods after introduction of the strains; finally, such methods may be in demand for protecting the rights of the owners and developers of the strains. The essence of the proposed identification method consists in the search of strain-specific DNA regions, which are absent in other genomes of the same species, and construction of a primer system for multiplex PCR, which allows simple, reliable, and rapid strain identification. The advantages of this approach relative to other identification techniques are, firstly, high reproducibility and, secondly, the fact that the method is based on detection of the structural variants, the contributions of which to the evolution of rhizobial genomes is rather high, whereas most of the genome fingerprinting techniques (AFLP, RAPD, REP, ERIC, etc.) are based on the detection of nucleotide polymorphisms in short genome fragments but miss a lot of events related to genome rearrangements and horizontal gene transfer. The method proposed can also be used for monitoring the evolutionary dynamics of rhizobial inoculant strains, particularly in unique fragments of the genome, which is very important for R. leguminosarum, where the proportion of unique sequences is much higher compared to other rhizobia.

A collection of twenty-eight strains isolated from root nodules of Astragalus inopinatus Boriss. and Astragalus umbellatus Bunge originating from the Kamchatka Peninsula (Russian Federation) was obtained for the first time. Analysis of the 16S ribosomal RNA gene sequence revealed a significant diversity of isolates belonging to 4 genera of the order Hyphomicrobiales: Mesorhizobium, Rhizobium, Bosea and Tardiphaga. The presence of phenotypically and taxonomically different strains (Bosea + Tardiphaga, Bosea + Mesorhizobium, Tardiphaga + Mesorhizobium, Bosea + Rhizobium) in some nodules of both plants was also observed. The symbiotic efficiency of strains isolated from A. inopinatus plants in the nodulation assay showed that most isolates of the genus Mesorhizobium and Rhizobium can form a nitrogen-fixing symbiosis with A. inopinatus, leading to a significant increase in plant biomass compared to the non-inoculated control.

A rhizosphere strain, Achromobacter insolitus LCu2, was isolated from alfalfa (Medicago sativa L.) roots. It was able to degrade of 50

In this article, we report the complete genome sequence of Microbacteriun strain A8/3-1 isolated from the root nodule of Oxytropis tragacanthoides Fisch. ex DC., growing in the Altai region, Russia. The sequence was obtained using Oxford Nanopore Technologies MinION.

The paper studies the genetic diversity of microorganisms isolated from root nodules of wild populations of the legumes Lathyrus pratensis L., Vicia cracca L., Trifolium repens L., and Astragalus schelichowii Turcz. collected near Norilsk (Arctic Russia). The taxonomic position of the 19 isolates obtained was determined by sequencing the 16S rRNA gene (rrs). The isolates were assigned to four genera of the order Hyphomicrobiales: Rhizobium, Pararhizobium, Bosea and Tardiphaga. Nine fast-growing isolates belonged to the genera Rhizobium and Pararhizobium. ITS region sequencing clarified the species identity of 6 rhizobial isolates. Isolates from V. cracca nodules were identified as Pararhizobium sp., P. herbae. Microsymbionts from T. repens were assigned to Rhizobium sp. and to the species R. beringeri, while isolates from L. pratensis were identified as P. herbae and R. beringeri. Symbiotic nodA and nodC genes were found in the Rhizobium strains P8/5-2, P9/1-1 and P9/3-2 from L. pratensis and T. repens nodules, nodA gene was detected in the Pararhizobium strains P7/3-1, P7/4-1, P7/5-1 from V. cracca nodules. Nine out of ten slow-growing isolates were assigned to the genus Bosea. Three isolates from the nodules of V. cracca were assigned to the species B. psychrotolerans. Six isolates from the nodules of A. schelichowii were identified as B. vaviloviae, B. lathyri and Bosea sp. The strain P22/3-5 isolated from the nodule of A. schelichowii was identified as Tardiphaga robiniae. Simultaneous presence of strains belonging to different genera of the order Hyphomicrobiales was detected in the nodules of V. cracca and A. schelichowii.

Nonylphenol (NP) is a ubiquitous environmental pollutant of major concern due to its toxicity to hydrobionts, animals, and humans. Moreover, NP is known as an endocrine disruptor. The aim of this study is to isolate from bottom sediments sampled in the southern Gulf of Finland (the Baltic Sea) and identify a highly-efficient NP-degrading bacterial strain and to analyze its NP-degrading capacity at different levels of temperature, initial pH, dissolved oxygen concentrations, and initial NP content. The isolated strain F8 was identified by phenotypic traits using standard methods and by Sanger sequencing of a fragment of the 16S rRNA gene sequence (rrs). NP content was determined by high-performance liquid chromatography. The novel NP-degrading bacterium Raoultella planticola F8 was isolated from the bottom sediments sampled in the Gulf of Finland. R. planticola F8 isolate was deposited in the Russian Collection of Agricultural Microorganisms (RCAM), All-Russia Research Institute for Agricultural Microbiology, as the strain RCAM 05450. The rrs sequence of the F8 isolate was deposited in the GenBank database (No. OL831016). This strain is highly efficient for NP degradation in aerobic conditions at different NP concentrations (up to 900 mg·L−1), in the temperature range of +5…+35 °C, the initial pH range of 5–9, and the dissolved oxygen concentration range of 0.8–2.46 mg·L−1. This is the first study to demonstrate the ability of R. planticola to degrade NP. Results of this investigation provide useful information for R. planticola F8 application in bioremediation processes.

Guar (Cyamopsis tetragonoloba (L.) Taub.) is an important legume plant used as food and industrial crop. Guar forms nitrogen-fixing symbiosis with nodule bacteria (rhizobia) supplying the plant with this important nutrient element. The ability to form symbiosis with rhizobia of various taxonomic groups of genera Bradyrhizobium and Ensifer is a common trait of guar with cowpea and soybean. Pot experiments were performed to compare nodulation and response of guar, cowpea and soybean to inoculation with nine strains isolated from guar nodules and belonging to the above-mentioned genera. Strains assigned to species Bradyrhizobium archetypum and Bradyrhizobium valentinum were isolated from nodules of guar for the first time. Nodule number and biomass on the inoculated guar roots significantly varied depending on the strain from 15 to 40 nodules per plant and from 20 to 54 mg dry weight (DW)/plant, respectively. Eight strains formed nitrogen-fixing symbiosis with cowpea. Nodule number and biomass on the cowpea roots varied depending on the strain from 19 to 67 nodules per plant and from 3 to 61 mg DW/plant, respectively. Significant differences among strains were also observed in acetylene reduction activity and positive effects of inoculation on shoot biomass and nitrogen content in shoots of plant species. However, symbiosis with soybean was inefficient, since only few small white nodules were observed and no effects were found on plant growth. Correlations between the symbiotic parameters in guar and cowpea dependent on the rhizobia strain were found and discussed in view of mechanisms underlying formation and functioning of nitrogen-fixing symbiosis. Several studied strains offer promise as inoculants for guar and cowpea and recommended for further field trials.

This study reports the whole-genome sequence of an endosymbiotic bacteria Bosea sp. strain 685, which was isolated from the root nodule of Astragalus umbellatus Bunge. in the Kamchatka Peninsula, Russia. The genome consists of one chromosome and one plasmid with a total length of 6,795,213 bp and 65.37% of GC content.

We present the genome sequence of Ensifer aridi strain RCAM05007 obtained from long reads. The strain was isolated from the root nodule of Cyamopsis tetragonoloba (L.) Taub. plant inoculated with a soil sample from India. The assembly contains one chromosome and two megaplasmids totalling ~6.7 Mbp with 61.6% GC content.

The ability of nine bacterial strains of the genus Rhizobium and Mesorhizobium, isolated from nodules of various species of legumes Oxytropis, Astragalus, Lathyrus, Vicia and Hedysarum growing in Arctic Yakutia, to form nitrogen-fixing symbiosis with Trifolium repens L., Medicago sativa L., Oxytropis adamsiana (Trautv.) Jurtzev and Astragalus frigidus L. under conditions of sterile test-tube experiment was studied. The ability of eight strains to form both ineffective and nitrogen-fixing nodules depending on the inoculation variant of legume plants was shown. The ability of O. adamsiana to form an effective symbiosis with three strains isolated from leguminous plants of the genera Hedysarum, Oxytropis and Astragalus allows us to classify it as promising for bioremediation of disturbed lands and creation of highly productive agrophytocenoses in various soil and climatic conditions of the Arctic.

Bacterial strains isolated from root nodules of the legume plant Hedysarum arcticum B. Fedtsch growing on Samoylov Island in the Lena River delta (Arctic zone of Yakutia) were assigned to the genera Rhizobium (family Rhizobiaceae) and Mesorhizobium (Phyllobacteriaceae) of the order Hyphomicrobiales (class Alphaproteobacteria) according to the rrs gene sequencing data. According to phylogenetic analysis of concatemers of the atpD, dnaK, gyrB, and rpoB genes, the strains belonged to the species Rhizobium giardinii and Mesorhizobium norvegicum. The strains were shown to be facultative psychrotrophs growing at 5 and 28°C. These microsymbionts are promising for further study of their symbiotic efficiency regarding other forage legume species, with an aim to establish highly productive agrophytocenoses in the Far North.

Permafrost is an extremely cold ecosystem that is inhabited by microorganisms with unique biochemical properties for potential biotechnological applications. Here, we present the complete genome sequence of Glutamicibacter sp. strain M10, which was isolated from a permafrost sample that had been collected at a depth of 2 m in West Spitsbergen, Norway.

Here, we present the draft genome sequence of Rhizobium sp. strain RCAM05973 which was isolated from a Cyamopsis tetragonoloba (guar) root nodule. The genome contains 6,937,221 bp in 2 contigs and has a GC content of 60%.

ABSTRACT The Shulgan-Tash (Kapova) cave is a unique object for scientific research. In this article, we report the draft genome sequence of Janibacter limosus strain P1(28)-3 (RCAM05316) isolated from cave lime mud, Russia (53° 2′ 0″ N, 57° 3′ 0″ E). The sequence was obtained using Oxford Nanopore Technologies MinION.

We report the draft genome sequence of Cupriavidus sp. strain D39, associated with the roots of pea plants. The genome is characterized by a GC content of 63.62% and a total length of 7.7 Mbp and contains several putative genes associated with resistance to metals and plant growth promotion.

This study reports the whole-genome sequence of an endosymbiotic bacterium, Rhizobium sp. strain 32-5/1, isolated from root nodules of the legume Vicia cracca L. in the Arctic region of Russia. The genome consists of two plasmids and one chromosome, with a total length of 5,621,108 bp and 59.5% GC content.

In this article, we report the complete genome sequences of Massilia sp. strains B-10 (RCAM05335) and H-1 (RCAM05339), which were isolated from the water of the Dal’nee Verkhnee Lake in the Shulgan-Tash cave in Russia (53°2′0″N, 57°3′0″E). The sequences were obtained using an Oxford Nanopore Technologies MinION system.

Microorganisms of extremely cold habitats are unique objects for studying their biogeochemical properties and mechanisms. Here, we present the complete genome sequence of the strain Rhodopseudomonas sp. P2A-2r, isolated from arctic soil in Svalbard, Norway. The genome consists of a 6.7-Mbp circular chromosome.

It is well known that plant-growth-promoting rhizobacteria (PGPRs) increase the tolerance of plants to abiotic stresses; however, the counteraction of Al toxicity has received little attention. The effects of specially selected Al-tolerant and Al-immobilizing microorganisms were investigated using pea cultivar Sparkle and its Al-sensitive mutant E107 (brz). The strain Cupriavidus sp. D39 was the most-efficient in the growth promotion of hydroponically grown peas treated with 80 µM AlCl3, increasing the plant biomass of Sparkle by 20% and of E107 (brz) by two-times. This strain immobilized Al in the nutrient solution and decreased its concentration in E107 (brz) roots. The mutant showed upregulated exudation of organic acids, amino acids, and sugars in the absence or presence of Al as compared with Sparkle, and in most cases, the Al treatment stimulated exudation. Bacteria utilized root exudates and more actively colonized the root surface of E107 (brz). The exudation of tryptophan and the production of IAA by Cupriavidus sp. D39 in the root zone of the Al-treated mutant were observed. Aluminum disturbed the concentrations of nutrients in plants, but inoculation with Cupriavidus sp. D39 partially restored such negative effects. Thus, the E107 (brz) mutant is a useful tool for studying the mechanisms of plant–microbe interactions, and PGPR plays an important role in protecting plants against Al toxicity.