Phenol degradation activity and reusability of Corynebacterium glutamicum coated with NH ₂-functionalized silica-encapsulated Fe ₃O ₄ nanoparticles

In this study, a novel method to immobilize and separate Corynebacterium glutamicum for phenol degradation was developed using Fe ₃O ₄ nanoparticles (NPs). The Fe ₃O ₄ NPs were encapsulated with silica and functionalized with NH ₂ groups to enhance their capacity to adsorb on the cell surface. The results showed that the NH ₂-functionalized silica-encapsulated Fe ₃O ₄ NPs strongly adsorbed on the cell surface of C. glutamicum during 32d culture without any interruptions of their normal cell growth. The coated C. glutamicum were easily separated from the culture broth within 2min by applying an external magnetic field Also, the coated C. glutamicum were able to completely degrade 50ppm phenol in the culture broth after 8d culture at 30°C. Concerning reusability, the coated cells could completely degrade phenol during the first 2 cycles, and retain ∼60% activity of phenol degradation for the third and four cycles.