title: Stereoselective nitrile hydrolysis by immobilized whole-cell biocatalyst.
abstract: The present work attempts to deal with the stability and reusability aspect of nitrilase from Alcaligenes faecalis for the production of (R)-(-)-mandelic acid. Four entrapment matrixes were screened to search for a suitable support, and alginate was found to have significant process advantages over its other counterparts. Thermodynamic analysis allowed us to account for decreased enantioselectivity (E) as a result of immobilization. The system was also characterized based on the Thiele modulus (phi). Efficient reusability of the biocatalyst up to 35 batches was achieved by immobilization as compared to 9 batches for free cells, and cross-linking extended it further to 40 batches. Finally, synthetic utility of the immobilized biocatalyst was demonstrated on a preparative scale to produce 640 g of (R)-(-)-mandelic acid with 97% enantiomeric excess (ee).
authors: Department of Pharmaceutical Technology, National Institute of Pharmaceutical Education and Research, Sector-67, SAS Nagar, Punjab, 160 062 India.
authors: Praveen
authors: P
authors: Kaul
authors: Anirban
authors: A
authors: Banerjee
authors: Uttam Chand
authors: UC
authors: Banerjee