| Nanoparticle-Supported Multi-Enzyme Biocatalysis | ||
| Wen-Fang Liu1, Mu-Qing Zheng2, Song-Ping Zhang2 and Ping Wang3, (1)Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100080, China; Beijing Institute of Technology, Beijing, 100081, China, (2)Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100080, China, (3)Department of Bioproducts and Biosystems Engineering, University of Minnesota, St Paul, MN 55108 Glutamate dehydrogenase (GLDH), lactate dehydrogenase (LDH) and coenzyme NAD+ were attached onto silica nanoparticles examined for biosynthesis of α-ketoglutarate from L-glutamate. The immobilized multi-enzyme catalyst retained about 50% of the activity of the free-enzyme system for the coupled reactions. Since nanoparticles always tend to agglomerate in the absence of dispersing agents such as surfactants, it was found that liquid-solid ratio of the reaction system had a great effect on the activity of the catalyst system. Overall, the particle-attached NAD+ showed effective interaction with the enzymes immobilized in the same way and achieved a TTN of around 20000 within one hour of reaction, corresponding to a glutamate conversion of 22.7%. Magnetic nanosilica particles were also examined for the immobilization of the catalyst system for easy catalyst recovery and reuse. Extended Abstract Status: Not Uploaded | ||