Isolation and Characterization of Nitrogen Fixing Bacteria from Rhizospher of Chickpea and Peanodules, Hossana, Ethiopia

Abstract

One of the ways to increase the competitive survivability of rhizobial bio fertilizers and achieve better plant growth under such conditions is by modifying the rhizospheric environment or community by addition of non rhizobial nodule-associated bacteria (NAB) that cause better nodulation and plant growth when co-inoculated with rhizobia. To achieve this objective experimental design was carried out. Rhizobium is the root of legumes host nitrogen fixing bacteria which can invade root and get sugars from the plant. A study was performed to investigate the most commonly associated nodule-associated bacteria and the rhizospheric microorganisms associated with the legume plant. Present study on Isolation and characterization of Nitrogen Fixing Bacteria from agricultural rhizosphere was carried out with the aim of Isolation and characterization of Nitrogen Fixing Bacteria. The occurrence of Nitrogen Fixing Bacteria from root nodule of pea, white chickpea and red chickpea were investigated. Nitrogen fixing bacteria was isolated from root nodule of pea, white chickpea and red chickpea. The isolates were grown on yeast extract – mannitol agar (YEMA), and the morphologic characterization was done by Gram stain. A total of 21 isolates were isolated on Yeast Extract Mannitol (YEMA) agar medium. The isolates were circular, and irregular in form with smooth surface; entire, colony margins; with light pink coloured. The identification of isolated pure cultures through colony morphology analysis, cellular morphology and biochemical properties are including gram staining (negative), catalase test (negative), Methyl red test (negative), voges proskaeur test (positive), citrate utilization test (positive), starch hydrolysis test (positive) and mannitol salt agar (positive). Among the 21 bacterial isolates isolated, 18 were shown the characteristic of rhizobia. The effect of these 18 isolates those shows the characteristics of rhizobia were performed and all of them are significant, while compared with controls. These isolates will be useful to produce efficient bio fertilizers for Agriculture.