Indoleacetic acid production by Rhizobium sp. from a leguminous tree, Erythrina indica.

Rhizobium sp. isolated from the root nodules of Erythrina indica Lamk., a leguminous tree, produced large amounts of indoleacetic acid (IAA) from tryptophan. L-Tryptophan (2 mg/ mL) was preferred to DL-tryptophan for IAA synthesis. Attempts were made to optimize the cultural requirements for an accelerated IAA production. An enrichment of the carbon-free incubation medium with maltose (1 %), MnSO4 x H2O (5 microg/mL), and Triton X-100 (100 ppm) promoted the synthesized IAA content of the medium by 480 %.