This study was conducted to isolate and identify Bacillus subtilis from different Rhizosphere of Tomato, wheat, Corn, Barley, Gumbo, and Berseem soils in AlMuthanna governorate, to test its efficiency to solubilize phosphate in broth media. Twenty five Rhizosphere soil samples were collected, then subjected to serial dilution and plated on Nutrient agar medium. Microscope and biochemical characterizes were used to diagnosis these bacterial isolates. Results showed that ten isolates were belong to B. subtilis. Ten isolates differed in their ability to solubilize tricalcium phosphate. Spectrophotometer was used to quantify the amount of solubilize phosphate in the broth medium at 430 nm. Isolates, which have local number B11 and B6 were superior in their efficiency to solubilize phosphate (34.03, 31.9 mg.L-1, respectively), whereas isolates number B22 and B17 gave the lowest amount of solubilized phosphate (33.09 and 20.63 mgP.L-1, respectively). In addition to that medium pH drop to 6.5 in medium inoculated with B11 isolate compared with 7.0 in control and it reach to 6.54 with B6 isolate with strong relationship with the increasing of solubilized phosphate.
Hassan Ali abdul- Ratha/ Agric. College/Baghdad Univ.
Abdallah Kreem Jbar// Agric. College/AlMuthanna Univ.