Isolation and Characterization of Azotobacter and Potash Solubilizing Bacteria Isolates from Rhizospheric Soil of Cauliflower (Brassica oleracea var. botrytis L.) Growing Areas of Kolhapur District, Maharashtra, India

Abstract

Nitrogen is a crucial nutrient for plant growth, development, and reproduction. Higher nitrogen levels enhance protein content and help reduce the bolting issue. The aim of the study is to isolate Azotobacter and potash solubilizing bacteria from rhizosphere of cauliflower in Kolhapur district and identify and characterize them and through systematic screening select the best performing Azotobacter and KSB isolates for their further use in cauliflower cultivation. Total twenty soil were collected from rhizospheric soil of cauliflower growing are in Kolhapur district among which Seven isolates of Azotobacter and three isolates of potash solubilizing bacteria were obtained. For KSB, two isolates were gram negative and one was gram positive, while all of the Azotobacter isolates that were collected were gram negative. Based on visual, microscopic, and several biochemical testing, all of the isolates were identified. Methyl Red, Nitrate Reduction, Starch Hydrolysis, Catalase, Indole Production, Oxidase, and Gelatine Hydrolysis were among the biochemical tests that were investigated. Most of the isolates showed positive while some showed negative test. Azotobacter I showed the maximum nitrogen fixing capacity 11.61 mg g-1of sucrose. Maximum solubilisation index was showed by KSB I (3.25) based on the solubilization index.