Isolation and Characterization of Indigenous Rhizosphere Bacteria Producing Gibberellic Acid and Indole Acetic Acid from Local Soybeans in South Sulawesi

This study aimed to isolate and characterize the indigenous rhizosphere bacteria producing Gibberellic Acid and Indole Acetic Acid as plant growth regulators isolated from local soybean of South Sulawesi, Indonesia. Several root samples and soil samples of soybean plants were collected from the rhizosphere of local soybeans in three different areas of South Sulawesi such as Soppeng, Bone and Takalar. There were fifty six isolates of bacteria taken from Soybean roots and soil and grouped into gram-positive bacteria and gram negative bacteria. There were 35 isolates that produced a thick slime or felt slimy when cultured on Natrium Broth media and the remaining 21 produced spores. The results showed considerable potential for the bacterial isolated to produce Gibbrelic Acid in high concentration. The best isolates of thick slime producing Gibberellin Acid was RK 30 (4.670 mg/ml), RK 17 (3.797 mg/ml), RK 15 (3.703) and RK 35 (3.222 mg/ml). There were 4 isolates that produced high concentrations of Indole Acetic Acid including RK 32 (2.794 mg / ml) followed by RK 8 (1.810 mg/ml), RK 23 (1.714 mg / ml), and RK 30 (1.678mg / ml) respectively.