Polycaprolactone (PCL) biodegradation activity and reusability of pseudozyma jejuensis coated with NH₂-functionalized silica-encapsulated Fe₃O₄ nanoparticles

In this study, a novel method to immobilize Pseudozyma jejuensis for polycaprolactone (PCL) biodegradation has been developed using Fe₃O₄ nanoparticles. The Fe₃O₄ nanoparticles were encapsulated with silica and functionalized with NH₂ groups to enhance their capacity to adsorb on the cell surface. The results show that the NH₂-functionalized silica-encapsulated Fe₃O₄ nanoparticles strongly adsorbed on the cell surface of P. Jejuensis without any interruptions of their normal cell growth. There was a significant increase in the total organic carbon (TOC) concentration of P. jejuensis cells coated with NH₂-functionalized silica-encapsulated Fe₃O₄ nanoparticles after 10 days biodegradation of PCL at 30 °C. Concerning reusability, the coated cells could completely degrade PCL during the first 2 cycles, and retain ∼80% activity for the third and 75% activity of PCL biodegradation for the fourth, fifth, and sixth cycles.