Abstract: The present invention provides an engineered nitrilase polypeptide capable of converting (1-cyanomethyl) cyclohexane-1-carbonitrile into (1-cyanocyclohexyl)-acetic acid. Utilizing advanced enzyme engineering techniques, the nitrilase exhibits enhanced stability and activity over natural variants. These engineered enzymes can hydrolyze a wide range of nitrile-containing compounds, including cyclic and aliphatic substrates. They handle higher substrate concentrations (200 g/L to 300 g/L), are thermostable above 50° C., and remain stable within a pH range of 5.5 to 8.0, making them suitable for various industrial applications. Their ability to convert substrates such as mandelonitrile, 2-(2-chlorophenyl)-2-hydroxyacetonitrile, 2-(6-methoxynaphthalen-2-yl)propanenitrile, and 2-[1-(aminomethyl)cyclohexyl]acetonitrile into corresponding carboxylic acids enables efficient and cost-effective production from diverse starting materials.