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【Objective】The present paper aimed to obstain Bacillus mucilaginosus from the rhizosphere soil of Luoyang tobacco plant and improve the content of available free potassium of plants in soil. 【Method】B. mucilaginosus in soil was identified by plate dilution coating, gram staining, physiological and biochemical detection and 16 S rDNA sequence analysis, and the potassium solubility of the strain was compared with that of the standard strain by sodium tetraphenylborate precipitation method. 【Result】Nine single colonies, which were round, white and transparent, with neat edges and smooth protruding, were isolated from the root soil samples of tobacco fields at different growth stages in three counties of Henan province. Which the physiological and biochemical characters of strain 005, 008 and standard strains, were facultative anaerobic bacteria, and hydrogen peroxide enzyme reaction, also can make the starch hydrolysis, sugar alcohol fermentation, nitrate reduction, in the determination of V-P with M. R results have shown positive, in litmus milk test reaction can produce acid reaction, cannot make gelatin liquefaction, which can use citrate. The 16 S rDNA sequences of strain 005（MN227334） and strain 008（MN227337） were 99% homologous to GenBank（EU048557）. It was identified as B. mucilaginosus. The results showed that the precipitation weight of strain 005, 008 and standard strain 23575 was 0. 140, 0. 136 and 0. 166 g, respectively, with a significant difference of 0. 05, which were all 0. 040 g higher than that of the blank group. 【Conclusion】In the rhizosphere soil of Luoyang tobacco plant, there are round, white and transparent facultative anaerobic bacillus coleformis, which can hydrolyze starch, ferment sugar alcohol, reduce nitrate, and have strong ability to release potassium. [ABSTRACT FROM AUTHOR]