Aminated Single-walled Carbon Nanotubes as Carrier for Covalent Immobilization of Phenylalanine Ammonia-lyase

作者：Bartha Vari Judith Hajnal; Bencze Laszlo Csaba; Bell Evelin; Poppe Laszlo; Katona Gabriel; Irimie Florin Dan; Paizs Csaba; Tosa Monica Ioana^*

来源：Periodica Polytechnica - Chemical Engineering, 2017, 61(1): 59-66.

DOI：10.3311/PPch.10417

• PAL
• aminated SwCNT
• covalent immobilization
• continuous-flow system

A new and efficient immobilized form of phenylalanine ammonia-lyase (PAL) was obtained by covalent linkage onto amino functionalized single-walled carbon nanotubes (SwCNT(NH2)) as carrier. The catalytic properties of the resulted nanostructured biocatalyst (SwCNT(NH2)-PAL) were tested in the kinetic resolution of racemic 2-amino-3-(thiophen-2-yl) propanoic acid 1 by ammonia elimination and in the enantiotope selective addition of ammonia onto (E)-3-(thiophen-2-yl) acrylic acid 2. SwCNT(NH2)-PAL was a durable biocatalyst in batch mode for ammonia elimination from 1 (>85% of original activity after 7 cycles) and in ammonia addition to 2 (>70% of original activity after 3 cycles in 6 M NH3, pH 10.0). The ammonia addition onto 2 was also studied in a continuous-flow microreactor packed with SwCNT(NH2)-PAL (2 M NH3, pH 10.0, 15 bar) in the 30-80 degrees C temperature range. No significant loss of PAL activity was observed over 72 h in the microreactor up to 60 degrees C. Productivity of SwCNT(NH2)-PAL at 30 degrees C was significantly higher in the enantiotope selective ammonia addition performed in a packed-bed reactor operated in continuousflow mode (r(flow) = 2.41 mmol min(-1) g(-1)) than in the reaction performed in batch system (r(batch) = 1.38 mmol min(-1) g(-1)).

• 出版日期2017