Aislamiento y caracterización morfológica-bioquímica de cepas de rizobios asociados del cultivo de fréjol

Abstract

Abstract: Because of the meaningful cultivated areas and capacity of setting atmospheric nitrogen through symbiosis among the soil bacterium (Rhizobium) and by the contribution in the diet of the people, leguminousare of both, agricultural and nutritional interest. The current investigation pretends both, the rhizobia strain isolation and morphological and biochemicalcharacterization which are associated with bean cultivation whose purpose is to establish a baseline for physiological tests and of the future fields aside from conservation of this microbial diversity. The samples were taken from bean plantations in the Loja canton. The nodules were extracted and taken to the laboratory where they were disinfectedand seeded in the yeast mannitol agar (YMA) + congo red(CR)medium. At the end of the planting and purification process, 18 strains were obtained. Of which 7 strains presented distinctive characteristics of fast-growing rhizobia, probably belonging to the genre Rhizobiumandin the GPA + PBC medium did not experience any tonality change and little growth was visualized. In the YLA+ RBmedium, the coloration of the 18 strains was blue, discarding the possibility of Agrobacterium.