Indole acetic acid (IAA) production by endophytic bacterial isolate Agrobacterium tumefaciens BE-1 from roots of Musa acuminata

Abstract

We have screened 23 endophytic isolates to estimate the production of indole acetic acid (IAA) from the root of the banana (Musa spp) by using Salkowski’s reagent spectrophotometric method with and without L- tryptophan supplement. Amongst 23 isolates only eight isolates, showed the ability to produce IAA. It is observed that one isolates out of eight produced maximum amount of IAA supplemented with and without L-tryptophan in medium. Based on morphological, cultural, biochemical and 16s rRNA gene sequencing method, this promising endophytic bacterial isolate (BE 1) was identified as Agrobacterium tumefaciens. IAA production of BE-1 was further confirmed by Thin-layer chromatography as well as by High-Performance Liquid Chromatography with and without L-tryptophan in medium. Statistical analysis was carried out using paired t-test to test whether the production of IAA significantly increased by using L-tryptophan in medium.