Characterization of a Heavy Metal-Resistant and Plant Growth-Promoting Rhizobacterium, Methylo-bacterium sp.

摘要

Department of Environmental Science and Engineering, Ewha Womans University - The role of soil microorganisms, specifically rhizobacteria, in the development of rhizoremediation techniques is important to speed up the process and to increase the rateof mobilization or absorption of heavy metals to the plant. In this study, Methylobacterium sp. SY-NiRl was isolated from the rhizosphere soils of plants in oil and heavy metal-contaminated soil. Based on its pink pig-mented colony, rod-shape cells, andbelonging in a-Proteobacteria, Methylobacterium sp. SY-NiRl is considered a pink-pigmented facultative methylotroph. SY-NiRl had the ability to produce indole acetic acid which is one of phytohormones. This bacterium showed resistance against multiple heavy metals such as Cd, Cr, Cu, Pb, Ni, Zn, and the order of its resistance based on EC_(50) was Zn>,Ni > Cu> Pb > Cd > Cr. Therefore, Methylobacterium sp. SY-NiRl can stimulate seed germination and plant-growth in soil contaminated with heavy metals.