(北京工商大学 北京食品营养与人类健康高精尖创新中心/北京市食品添加剂工程技术研究中心/ 食品质量与安全北京实验室/北京市食品风味化学重点实验室, 北京 100048)
(Beijing Advanced Innovation Center for Food Nutrition and Human Health/Beijing Engineering and Technology Research Center of Food Additives/Beijing Laboratory for Food Quality and Safety/Beijing Key Laboratory of Flavor Chemistry, Beijing Technology and Business University,Beijing 100048, China)
The nano-spherical polyelectrolyte brush with polystyrene as the core and grafted acrylic monomer was synthesized by photoemulsion polymerization. The microsphere structure was characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy and laser particle size analyzer. The immobilization of alkaline protease was studied by using a ball brush as a carrier.The results showed that the prepared nano-spherical polyelectrolyte brush carrier had an average particle size of about 80nm, uniform size, and good dispersion. The optimal immobilization conditions for alkaline protease were buffer pH 9.0, immobilization time 6 h, and enzyme solution addition 1.2mg/mL.Compared with the free enzyme, the optimum pH (changed from 11.0 to 9.0). The optimum reaction temperature was 60℃, which increased 15℃ compared with free enzymes. Both temperature stability and acid-base stability were higher than free enzymes. The application range of the enzyme is widened, which is more conducive to industrial production.