Pantoea trifolii sp. nov., a novel bacterium isolated from Trifolium rubens root nodules.

A novel bacterium, designated strain MMK2, was isolated from a surface-sterilised root nodule of a Trifolium rubens plant growing in south-eastern Poland. Cells were Gram negative, non-spore forming and rod shaped. The strain had the highest 16S rRNA gene sequence similarity with P.

Assessment of Phenanthrene Degradation Potential by Plant-Growth-Promoting Endophytic Strain 23aP Isolated from (Hacq.) Rothm.

Polycyclic aromatic hydrocarbons (PAHs) are common xenobiotics that are detrimental to the environment and human health. Bacterial endophytes, having the capacity to degrade PAHs, and plant growth promotion (PGP) may facilitate their biodegradation. In this study, phenanthrene (PHE) utilization of a newly isolated PGP endophytic strain of 23aP and factors affecting the process were evaluated.

Cadmium-resistant Chryseobacterium sp. DEMBc1 strain: characteristics and potential to assist phytoremediation and promote plant growth.

The effectiveness of phytoremediation is closely related to the various interactions between pollutants, soil particles, rhizosphere microorganisms, and plants. Therefore, the object of current study was a cadmium-tolerant bacterium isolated from the rye rhizosphere, with a high degree of genetic similarity to the genus Chryseobacterium. Chryseobacterium sp.

Genetic and physiological diversity of white Spanish broom (Chamaecytisus albus) endophytes.

Chamaecytisus albus (Spanish broom) is a legume shrub that can be found in only one natural locality in Poland. This specimen is critically endangered; therefore, different actions focusing on protection of this plant in the natural habitat are undertaken, and one of them involves studies of the population of Chamaecytisus albus bacterial endophytes, which in the future could be used as bioprotectants and/or biofertilizers. A collection of 94 isolates was obtained from Spanish broom nodules, and the physiological and genetic diversity of these strains was studied.

Host-dependent symbiotic efficiency of Rhizobium leguminosarum bv. trifolii strains isolated from nodules of Trifolium rubens.

Trifolium rubens L., commonly known as the red feather clover, is capable of symbiotic interactions with rhizobia. Up to now, no specific symbionts of T.

Diversity and plant growth promoting properties of rhizobia isolated from root nodules of Ononis arvensis.

This is the first report describing isolates from root nodules of Ononis arvensis (field restharrow). The aim of this investigation was to describe the diversity, phylogeny, and plant growth promoting features of microsymbionts of O. arvensis, i.

Electrophoretic profiles of lipopolysaccharides from Rhizobium strains nodulating Pisum sativum do not reflect phylogenetic relationships between these strains.

Rhizobia that nodulate peas comprise a heterogeneous group of bacteria. The aim of this study was to investigate the relationship between phylogeny and electrophoretic and hydroxy fatty acid lipopolysaccharide (LPS) profiles of pea microsymbionts. Based on amplified fragment length polymorphism (AFLP) fingerprinting data, the pea microsymbionts were grouped into two clusters distinguished at 58% similarity level.

Purification and characterization of laccase from Sinorhizobium meliloti and analysis of the lacc gene.

The soil native bacterial strains were screened for laccase activity. Bacterial strain L3.8 with high laccase activity was identified as Sinorhizobium meliloti.

Nodulation competitiveness of Ensifer meliloti alfalfa nodule isolates and their potential for application as inoculants.

Alfalfa (Medicago sativa) is a widely cultivated legume, which enters into nitrogen-fixing symbiosis with Ensifer (Sinorhizobium) spp. In this study, an autochthonous rhizobial population of Ensifer sp. occupying alfalfa nodules grown in arable soil was used as the basis for selection of potential inoculants.

Rhizobium pisi sv. trifolii K3.22 harboring nod genes of the Rhizobium leguminosarum sv. trifolii cluster.

The taxonomic status of the Rhizobium sp. K3.22 clover nodule isolate was studied by multilocus sequence analysis (MLSA) of 16S rRNA and six housekeeping chromosomal genes, as well as by a subsequent phylogenic analysis.

Competitiveness of Rhizobium leguminosarum bv. trifolii strains in mixed inoculation of clover (Trifolium pratense).

Rhizobium leguminosarum by. trifolii (Rlt) establishes beneficial root nodule symbiosis with clover. Twenty Rlt strains differentially marked with antibiotic-resistance markers were investigated in terms of their competitiveness and plant growth promotion in mixed inoculation of clover in laboratory experiments.

Intragenomic diversity of Rhizobium leguminosarum bv. trifolii clover nodule isolates.

Background: Soil bacteria from the genus Rhizobium are characterized by a complex genomic architecture comprising chromosome and large plasmids. Genes responsible for symbiotic interactions with legumes are usually located on one of the plasmids, named the symbiotic plasmid (pSym). The plasmids have a great impact not only on the metabolic potential of rhizobia but also underlie genome rearrangements and plasticity.

Genetic and metabolic divergence within a Rhizobium leguminosarum bv. trifolii population recovered from clover nodules.

Rhizobia are able to establish symbiosis with leguminous plants and usually occupy highly complex soil habitats. The large size and complexity of their genomes are considered advantageous, possibly enhancing their metabolic and adaptive potential and, in consequence, their competitiveness. A population of Rhizobium leguminosarum bv.

Pretreatment of clover seeds with nod factors improves growth and nodulation of Trifolium pratense.

The increase in legume production in sustainable agriculture depends not only on the effectiveness of the selected nitrogen-fixing inoculants but also on their competitiveness in a soil environment containing an indigenous rhizobial population. In this study, we investigated the effect of pretreatment of red clover seeds with specific Nod factor (LCOs) on germination, growth, and nodulation of clover growing under sterile conditions and in the soil. We demonstrated that, although the symbiotic ability and competitiveness of the inoculant strain RtKO17 was not improved under competitive soil conditions, LCOs treatment of clover seeds significantly enhanced clover nodulation and growth of plants.

Response to flavonoids as a factor influencing competitiveness and symbiotic activity of Rhizobium leguminosarum.

Flavonoids play a crucial role as signal molecules in promoting the formation of nodules by symbiotic bacteria commonly known as rhizobia. The early interaction between flavonoids and NodD regulatory protein activates nod gene transcription and the synthesis of Nod factor that initiates nodule primordium. In this study, we assessed response to flavonoids as factors influencing competitiveness of rhizobia and their symbiotic activity.

Increased metabolic potential of Rhizobium spp. is associated with bacterial competitiveness.

Of 105 rhizobial isolates obtained from nodules of commonly cultivated legumes, we selected 19 strains on the basis of a high rate of symbiotic plant growth promotion. Individual strains within the species Rhizobium leguminosarum bv. trifolii, R.

The nadA gene of Pseudomonas fluorescens PGPR strain 267.1.

An insertion mutant of Pseudomonas fluorescens PGPR strain 267.1 was found to be auxotrophic for niacin (nicotinic acid) and could not synthesize quinolinic acid. The Tn5 interrupted gene was cloned and sequenced.