Isolation of promising strains of <i>Bacillus megaterium </i>and <i>Bacillus subtilis</i> with phosphate mobilizing and antimicrobial properties
This article presents data on the isolation and study of physiological and biochemical properties of cultures of Bacillus megaterium and Bacillus subtilis . The samples of black earth soils of wheat fields were used as materials for isolation of cultures, where 36 isolates with antimicrobial and 17 isolates with phosphate mobilizing properties were isolated from the samples. Microscopic observation of these isolates has shown that they are gram - positive, rod - shaped endospor - forming bacteria. According to cultural morphological and physiological - biochemical features, isolated isolates were identified as Bacillus subtilis and Bacillus megaterium. The efficiency of phosphate mobilization of Bacillus megaterium strains was studied. As a result, 5 of 17 isolates are showed the highest solubilizing capacity on a solid medium. Solubilizing ability was determined on NBRIP liquid medium, where the content of dissolved phosphorus increased in 4-7 times, and the pH of the cultural liquid in these strains decreased from 7.0 to 5.1-5.4. The antagonistic activity of isolated strains of Bacillus subtilis and Bacillus megaterium against 2 test strains, Fusarium graminearum and Fusarium oxysporum , was also carried out. On the basis of the data obtained, strains of Bacillius megaterium AA4, AA7, AA8, AA15 and AA17, as well as strains of Bacillus subtilis AS7, AS14, AS22, AS29 and AS34 have antagonistic activity against F. graminearum and F. oxysporum .