Nitrilase mediated conversion of Indole-3-acetonitrile to Indole-3-acetic acid

An attempt has been made for the conversion of Indole-3-acetonitrile to Indole-3-acetic acid using whole cells of a thermostable nitrilase producing Streptomyces sp. MTCC 7546 as an enzyme source. The whole cell enzyme activity showed a broad pH range of action with an optimum at 7.5. The optimal temperature for the maximum conversion was 60 °C. The whole cells also showed good thermal stability with half-lives of 8 h at 50 °C, 5 h at 60 °C and 0.5 h at 70 °C, respectively. The Km and Vmax calculated from the Lineweaver plot were 1.3 mM and 28 µM/min. Among different solvents used for assessment on activity, 10% methanol (v/v of reaction mixture) showed maximum nitrilase specific cell activity. TLC, HPLC, FTIR and mass spectroscopy were performed for identification, confirmation as well as quantification of Indole 3-acetic acid.