Formation of Nitrile Hydratase CLEAs in Mesoporous Silica

Formation of Nitrile Hydratase Cross-Linked Enzyme Aggregates in Mesoporous Onion-like Silica: Preparation and Catalytic Properties

Jing Gao, Qi Wang, Yanjun Jiang*, Junkai Gao, Zhihua Liu, Liya Zhou, and Yufei Zhang,

Ind. Eng. Chem. Res., 2015, 54 (1), pp 83–90

Nitrile hydratase CLEAs) were formed in mesoporous onion-like silica (NHase-CLEAs@MOS) by using macromolecular dextran polyaldehyde as a cross-linker through the carrier-bound CLEAs method. Effect of pH, thermal and storage stability, and kinetic parameters of NHase-CLEAs@MOS were also studied. The maximum amount of NHase absorbed in MOS was 535 mg/g. Under optimized conditions, the maximum activity recovery of NHase-CLEAs@MOS was 48.2%. The stabilities of NHase-CLEAs@MOS were improved significantly compared to the NHase@MOS prepared by physical adsorption and free NHase.

Immobilization of nitrilase for synthesis of 2-hydroxy-4-(methylthio) butanoic acid

Immobilization of nitrilase on bioinspired silica for efficient synthesis of 2-hydroxy-4-(methylthio) butanoic acid from 2-hydroxy-4-(methylthio) butanenitrile  from Li-Qun Jin, Dong-Jing Guo, Zong-Tong Li, Zhi-Qiang Liu, Yu-Guo Zheng

Journal of Industrial Microbiology & Biotechnology, DOI 10.1007/s10295-016-1747-5

This paper describes a simple and effective method to immobilize recombinant nitrilase, for efficient production of 2-hydroxy-4-(methylthio) butanoic acid from 2-hydroxy-4-(methylthio) butanenitrile. The immobilized enzyme displayed better thermal stability, pH stability and shelf life compared to free nitrilase. Moreover, it showed excellent reusability and could be recycled up to 16 batches without significant loss in activity. 200 mM 2-hydroxy-4-(methylthio) butanenitrile was completely converted by the immobilized enzyme within 30 min, and the accumulation amount of 2-hydroxy-4-(methylthio) butanoic acid reached 130 mmol/g of immobilized beads after 16 batches.