Bio production of Indole 3-Acetic Acid by Bacillus pumilus DS5 isolated from agricultural field soils of Andhra Pradesh

Bacillus pumilus DS5, a plant growth-promoting bacterium, was isolated from soil samples taken from agricultural fields in the vicinity of Guntur, Andhra Pradesh. The isolate was characterized using morphological, biochemical, and physiological methods to determine its taxonomic position. The bacterium was identified by sequencing its 16S rRNA and depositing the sequences in GenBank (NCBI) under accession number (MG870111). The strain was found to produce Indole Acetic Acid (IAA) in YEM broth medium, and the production of IAA was further studied in optimization experiments. The effects of incubation period, pH, temperature, vitamins, carbon, and nitrogen sources on IAA production were investigated. The maximum IAA production of 105 µg/ml was observed after 48 h of incubation using 0.1% L-tryptophan at pH 7.0. Additionally, the effects of different carbon and nitrogen sources on IAA production were examined. Sucrose and yeast extract were found to be the best carbon and nitrogen sources, respectively, for maximum production of IAA. These results suggest that Bacillus pumilus DS5 could be a useful bacterium for promoting plant growth promoting studies.