Populations of Rhizobium leguminosarum biovar viciae were sampled from two bulk soils, rhizosphere, and nodules of host legumes, fava bean (Vicia faba) and pea (Pisum sativum) grown in the same soils. Additional populations nodulating peas, fava beans, and vetches (Vicia sativa) grown in other soils and fava bean-nodulating strains from various geographic sites were also analyzed. The rhizobia ...

Rhizobia are non-spore-forming soil bacteria that fix atmospheric nitrogen into ammonia in a symbiosis with legume roots. However, in the absence of a legume host, rhizobia manage to survive and hence must have evolved strategies to adapt to diverse environmental conditions. The capacity to respond to variations in nutrient availability enables the persistence of rhizobial species in soil, and ...

The formation of a nitrogen-fixing nodule requires the coordinated development of rhizobial colonization and nodule organogenesis. Based on its mutant phenotype, lumpy infections (lin), LIN functions at an early stage of the rhizobial symbiotic process, required for both infection thread growth in root hair cells and the further development of nodule primordia. We show that spontaneous nodulati...

Two diametric paradigms have been proposed to model the molecular co-evolution of microbial mutualists and their eukaryotic hosts. In one, mutualist and host exhibit an antagonistic arms race and each partner evolves rapidly to maximize their own fitness from the interaction at potential expense of the other. In the opposing model, conflicts between mutualist and host are largely resolved and t...

Rhizobia are nitrogen-fixing soil bacteria that establish endosymbiosis with some leguminous plants. The completion of several rhizobial genome sequences provides opportunities for genome-wide functional studies of the physiological roles of many rhizobial genes. In order to carry out genome-wide phenotypic screenings, we have constructed a large mutant library of the nitrogen-fixing symbiotic ...

The purpose of this study was to determine the effectiveness Spirulina platensis for remediation vannamei shrimp culture waste. method used in a Non-Factoral Completely Randomized Design (CRD) with 4 treatments and 3 replications, namely (A) Control; (B) 50% waste (1500 ml + 1500 water) technical fertilizer inoculant; (C) 75% (2,250 750 (D) 100% inoculant. Data analysis ANOVA 95% confidence lev...

Low soil fertility in savanna soils has been linked to low crop yields, with nitrogen being the most limiting factor yield. Soil used this pot experiment was obtained from Motshephiri village total N, NO3− and high NH4+. A conducted a greenhouse laid Randomized Complete Block Design four treatments (1) control, (2) Bradyrhizobium japonicum inoculant, (3) superphosphate (4) inoculant + superphos...

The relationship between environment and abundance of rhizobia was described by determining the populations of root nodule bacteria at 14 diverse sites on the island of Maui. Mean annual rainfall at the sites ranged from 320 to 1,875 mm, elevation from 37 to 1,650 m, and soil pH from 4.6 to 7.9. Four different soil orders were represented in this study: inceptisols, mollisols, ultisols, and an ...

The symbiotic relationship between the soybean plant and rhizobium results in fixation of atmospheric nitrogen (N(2)) in the root nodules, with the result that nitrogenous fertilization of the soybean is unnecessary. The effectiveness of nodule formation and N(2) fixation with rhizobial strains is under genetic control with two general categories identified: (1) promiscuous, which produces func...

Bacteria belonging to the genera Rhizobium, Mesorhizobium, Sinorhizobium, Bradyrhizobium, and Azorhizobium (collectively referred to as rhizobia) grow in the soil as free-living organisms but can also live as nitrogen-fixing symbionts inside root nodule cells of legume plants. The interactions between several rhizobial species and their host plants have become models for this type of nitrogen-f...