The symbiotic interaction between Rhizobium etli and Phaseolus vulgaris, the common bean plant, ultimately results in the formation of nitrogen-fixing nodules. Many aspects of the intermediate and late stages of this interaction are still poorly understood. The R. etli relA gene was identified through a genome-wide screening for R. etli symbiotic mutants. RelA has a pivotal role in cellular phy...

We present the genome sequence of Rhizobium sp. strain CCGE510, a nitrogen fixing bacterium taxonomically affiliated with the R. leguminosarum-R. etli group, isolated from wild Phaseolus albescens nodules grown in native pine forests in western Mexico. P. albescens is an endangered bean species phylogenetically related to P. vulgaris. In spite of the close host relatedness, Rhizobium sp. CCGE51...

Thirty-one strains of two new genomic species (genomic species 1 and 2) of rhizobia isolated from root nodules of Phaseolus vulgaris and originating from various locations in France were compared with reference strains of rhizobia by performing a numerical analysis of 64 phenotypic features. Each genomic species formed a distinct phenon and was separated from the other rhizobial species. A comp...

The plasmid-borne Rhizobium etli katG gene encodes a dual-function catalase-peroxidase (KatG) (EC 1.11.1.7) that is inducible and heat-labile. In contrast to other rhizobia, katG was shown to be solely responsible for catalase and peroxidase activity in R. etli. An R. etli mutant that did not express catalase activity exhibited increased sensitivity to hydrogen peroxide (H(2)O(2)). Pre-exposure...

Bacterial L-asparaginase has been a universal component of therapies for childhood acute lymphoblastic leukemia since the 1970s. Two principal enzymes derived from Escherichia coli and Erwinia chrysanthemi are the only options clinically approved to date. We recently reported a study of recombinant L-asparaginase (AnsA) from Rhizobium etli and described an increasing type of AnsA family members...

Abstract A collection of 160 isolates of rhizobia nodulating Phaseolus vulgaris in three geographical regions in Tunisia was characterized by restriction fragment length polymorphism analysis of polymerase chain reaction (PCR)-amplified 16S rDNA, nifH and nodC genes. Nine groups of rhizobia were delineated: Rhizobium gallicum biovar (bv.) gallicum, Rhizobium leguminosarum bv. phaseoli and bv. v...

Recent studies have shown that living and heat-killed cells of the rhizobacterium Rhizobium etli strain G12 induce in potato roots systemic resistance to infection by the potato cyst nematode Globodera pallida. To better understand the mechanisms of induced resistance, we focused on identifying the inducing agent. Since heat-stable bacterial surface carbohydrates such as exopolysaccharides (EPS...

Rhizobium etli mutants unable to grow on asparagine as the nitrogen and carbon source were isolated. Two kinds of mutants were obtained: AHZ1, with very low levels of aspartase activity, and AHZ7, with low levels of asparaginase and very low levels of aspartase compared to the wild-type strain. R. etli had two asparaginases differentiated by their thermostabilities, electrophoretic mobilities, ...