Preparation, characterization and stability of cross linked nitrilase aggregates (nitrilase–CLEAs) for hydroxylation of 2-chloroisonicotinonitrile to 2-chloroisonicotinic acid

Autor: Amol Gulab, Khatik, Arvind Kumar, Jain, Abhijeet Bhimrao, Muley
Rok vydání: 2022
Předmět:
Zdroj: Bioprocess and Biosystems Engineering. 45:1559-1579
ISSN: 1615-7605
1615-7591
DOI: 10.1007/s00449-022-02766-0
Popis: Nitrilases capable of performing hydroxylation of 2-chloroisonicotinonitrile to 2-chloroisonicotinic acid were screened, and ES-NIT-102 was the best nitrilase for said biotransformation. Nitrilase was immobilized as cross linked enzyme aggregates (nitrilase-CLEAs) by fractional precipitation with iso-propanol, and cross linked with glutaraldehyde. The nitrilase-CLEAs prepared with optimized 35 mM glutaraldehyde for 120 min cross linking time had 82.36 ± 4.45% residual activity, and displayed type-II structural CLEAs formation as confirmed by particle size, SEM, FTIR, and SDS-PAGE analysis. Nitrilase-CLEAs had superior pH and temperature stability, showed a shift in optimal temperature by 5 °C, and retained nearly 1.5 to 1.7 folds activity over free nitrilase at 50 °C and 55 °C after more than 9 h incubation. Nitrilase-CLEAs showed reduced affinity and decreased conversion of substrate as indicated by slightly higher K
Databáze: OpenAIRE