In this present study, a biosurfactant producing microorganism,
identified as Pseudomonas sp. AJ15, was selected to perform the
experiments on the basis of its plant growth promoting traits and
ability to degrade petroleum oil. This strain was isolated from petroleum
oil contaminated soil and stored in our laboratory. The
inoculum was prepared by transferring a loopful of bacterial culture
into 25 ml nutrient medium (composition g/l beef extract-3 g,
peptone-5 g, NaCl-5 g) in 250 ml Erlenmeyer flask and incubated at
30 C for 24 h. This inoculum contained 108 cells/ml.