In present study, the isolate SUP III showed maximum siderophore production in Burk’s medium with maximum 43% decolorization of CAS reagent in liquid CAS assay. Optimum yield of siderophore was obtained at pH 7.2. The culture was identified as Azotobacter sp. based on 16S rRNA gene sequencing and phylogenetic studies using MEGA 4. The siderophore extraction and purification was achieved using XAD2 column. Colorimetric reactions prove that purified siderophore is of catecholate type. Fourier – transform infrared (FTIR) analysis showed peaks at 3402 cm-1, 1652 cm-1, 1032 cm-1, and 1112 cm-1 which supported the colorimetric results. Antimicrobial activity of the purified siderophore showed significant zones of inhibition for some pathogens. This type of study has not been previously reported in this area.
Azotobacter sp., Siderophore, CAS agar, FTIR, XAD2