Functional magnetic mesoporous nanoparticles for efficient purification of laccase from fermentation broth in magnetically stabilized fluidized bed.

A magnetically stabilized fluidized bed (MSFB) with the Cu(2+)-chelated magnetic mesoporous silica nanoparticles (MMSNPs-Cu(2+)) was established to purify laccase directly from the fermentation broth of Trametes versicolor. The MMSNPs-Cu(2+) particles in the MSFB maintained a stable bed expansion of two to threefold at a flow rate of 120-180 cm/h. At the optimal magnetic field intensity of 120 Gs, both the maximal Bodenstein number and the smallest axial dispersion coefficient were achieved, which resulted in a stable fluidization stage. The dynamic binding capacity of laccase in the MSFB decreased from 192.5 to144.3 mg/g when the flow velocity through the bed increased from 44.2 to 69.8 cm/h. The MSFB with MMSNPs-Cu(2+) achieved efficient laccase purification from the fermentation broth with 62.4-fold purification of laccase and 108.9 % activity yield. These results provided an excellent platform for the application of these magnetic mesoporous nanoparticles integrated with the MSFB in developing novel protein purification process.