Farmers extract organic biofertilizer (FEOB), known as a local wisdom technology, has been widely used a significant role in demonstrating the ecological value of traditional practices in sustainable agriculture. FEOB utilize diverse microbial communities and rich in beneficial microbes, including plant growth-promoting bacteria (PGPB), to enhance nutrient bioavailability and support maize growth. This research aims to assess the synergistic interactions among three selected PGPB. The characterization and biochemical activity test were conducted to assess nitrogenase activity, production of indole acetic acid (IAA), organic acid and bioassay was conducted to evaluate the synergistic effects between the isolates. The results of the synergistic test of PGPB demonstrated a synergistic interaction between isolates N1, N3, and N6. The consortium of N136 exhibited the greatest value for plant height (30.17 cm, or approximately 68.83% higher than the control) and root length (33.33 cm, or 115.45%). Furthermore, the isolates exhibited nitrogenase activity, capable of producing IAA and organic acids, which significantly increased the chlorophyll content and biomass of maize plants by 93.62% and 94.74%, respectively, compared to the control. This finding suggests that the consortium of PGPB can be developed as an active ingredient of bioagent or biofertilizers for enhancing the agronomic characteristics of maize.