ISOLATION, CHARACTERIZATION AND IDENTIFICATION OF MULTIFACETED HALOTOLERANT BACILLUS LICHENIFORMIS AND BACILLUS WUDALIANCHIENSIS FROM RHIZOSPHERIC SOILS OF BANGALORE

Abstract

Plant growth promotion through versatile microorganisms inhabiting the rhizospheric region of the soil has emerged as a sustainable approach in improving the crop productivity and crop health management. The present study reports the isolation and characterization of halotolerant as well as drought tolerant isolates that possess exceptional plant growth promotional attributes. Out of 32 isolates obtained, 13 isolates exhibited excellent plant growth promotional attributes such as phosphate solubilization, phytohormone production, siderophore production etc. Among 13 isolates tested for stress tolerance studies, two isolates Mulberry -1 and Ragi-7 were able to tolerate both drought and saline stresses and were further identified as Bacillus licheniformis and Bacillus wudalianchiensis based on biochemical and molecular techniques. Antibiosis activity of both the isolates tested against two important plant pathogens Fusarium oxysporum and Phomopsis vexans was found to be positive. Bacillus licheniformis and Bacillus wudalianchiensis were further tested for their efficacy to solubilize five different inorganic phosphate sources. The amount of phosphate liberated was found to be highest (3562 mgml-1 and 1894 mgml-1) with diammonium phosphate followed by single super phosphate and tricalcium phosphate with respect to Bacillus licheniformis and Bacillus wudalianchiensis. Zea mays L. seeds treated with the culture filtrate of both the isolates were cultivated on Murashige-Skoog medium under In-vitro conditions. Bacillus wudalianchiensis was found to be better compared to Bacillus licheniformis with respect to plant growth promotional aspects as they were able to increase the root and shoot length of Zea mays L. under In-vitro conditions. Application of the multifaceted capabilities of unexplored halotolerant strain of Bacillus wudalianchiensis could open up a new avenue in plant biotechnology.