'current 1 Antibiotic removal 1 Antibiotics 1 Catalyst activity 1 Cloning 1 Enzyme activity 1 Enzyme immobilization 1 Enzymes activity 1 Escherichia coli 1 Free enzyme Immobilisation 1 Immobilized enzyme 1 Lactamases 1 Magnetic separation 1 Magnetite 1 Nanobiocatalyst 1 Penicillin G 1 Reusability 1 Silica 1 Water resources 1 Waters resources 1 antibiotic removal 1 enzyme immobilization 1 nanobiocatalyst 1 wastewater 1