Organic acid
production was determined using high performance liquid chromatography (HPLC). The PSB
populations were higher in rhizosphere than non-rhizospheric soil and the highest population was
found in PS and Pikovskaya, while the lowest was found in PA media plates. The highest P solubilizing
activity (69.58%) was found in PSB9 strain grown in NBRIP plate. Isolated PSB were able to produce
different organic acids and growth hormone such as IAA. A number of PSB isolates belong to the
Bacillus sp. and proved for the antagonistic effect against R. solani (sheath blight) even though most of
the isolated strains can grow in nitrogen, free semi-solid medium and able to produce siderophore. PSB
inoculants with their beneficial traits would be considered as potential biofertilizer for the sustainable
aerobic rice cultivation system.