ISOLATION AND CHARACTERIZATION OF NITROGEN-FIXING AND GA3 PRODUCING BACTERIA FROM RICE RIZHOSPHERE OF RAINFED RICE FIELD IN SOUTH SULAWESI, INDONESIA

Nitrogen fixing bacteria can fix nitrogen and produce hormones. The surrounding environment strongly influences the ability of a bacterial strain to survive and produce metabolites. The same type of bacteria from different places does not necessarily have the same potential. This study aims to obtain and determine the characteristics of rhizosphere bacteria originating from rainfed rice fields in South Sulawesi, which can fix nitrogen and produce the hormone gibberellin (GA3). This study was conducted by taking samples from the rhizosphere of rice plants in three South Sulawesi districts in rainfed rice fields. The results showed 12 isolates that we can grow on nitrogen-free media with various morphological and biochemical characters and can fix nitrogen and produce GA3. NG4.1 isolate from Gowa produced the highest nitrogen concentration of 0.157%. Isolate NG7.1 from Gowa produced the highest GA3 hormone, 3,936 mg L-1. Character profiles and isolates' physiological abilities need to be the basis for developing biofertilizers and biostimulants to develop environmentally-friendly rice cultivation.