Isolation and characterization of diazotrophic growth promoting bacteria from rhizosphere of agricultural crops of Korea

plant namely sesame, maize, wheat, soybean, lettuce, pepper and rice grown in Chungbuk Province, Korea. Five isolates with nitrogenase activity above 150 nmol h(-1) mg(-1) protein were identified based on phenotypic and 16S rDNA sequences analysis. The strains were identified as Stenotrophomonas maltophilia (PM-1, PM-26), Bacillus fusiformis (PM-5, PM-24) and Pseudomonas fluorescens (PM-13), respectively. All the isotates produced indole-3-acetic acid (IAA), in the presence of tryptophan, ranging from 100.4 mu g ml(-1) (PM-13) to 255 mu g Ml(-1) (PM-24). The isolate PM-24 (Bacillus fusiformis) exhibiting highest nitrogenase activity (3677.81 nmol h(-1) mg(-1) protein) and IAA production (255 mu g ml(-1)) has a promising potential for developing as a plant growth promoting rhizobacteria. (c) 2004 Elsevier GrnbH. All rights reserved.