CATABOLISM OF INDOLE-3-ACETIC-ACID AND 4-CHLOROINDOLE-3-ACETIC AND 5-CHLOROINDOLE-3-ACETIC ACID IN BRADYRHIZOBIUM-JAPONICUM

Some strains of Bradyrhizobium japonicum have the ability to catabolize indole-3-acetic acid, Indoleacetic acid (IAA), 4-chloro-IAA (4-Cl-IAA), and 5-Cl-IAA were metabolized to different extents by strains 61A24 and 110, Metabolites were isolated and analyzed by high-performance liquid chromatography and conventional mass spectrometry (MS) methods, including MS-mass spectroscopy, UV spectroscopy, and high-performance liquid chromatography-MS. The identified products indicate a novel metabolic pathway in which IAA is metabolized via dioxindole 3-acetic acid, dioxindole, isatin, and 2-aminophenyl glyoxylic acid (isatinic acid) to anthranilic acid, which is further metabolized, Degradation of 4-Cl-IAA apparently stops at the 4-Cl-dioxindole step in contrast to 5-Cl-IAA which is metabolized to 5-Cl-anthranilic acid.