Degradation pathway of penicillin by immobilized ß-lactamase

The ever-emerging environmental pollution as a result of the abuse of antibiotics and other pollutants has caused a serious threat to the ecological environment and human health. Therefore, development of effective strategies for degradation, as well as disposal of antibiotic residues in water is urgently needed. Antibiotics, such as penicillins, are extensively utilized for treatment of bacterial infections for humans and animals and have been spreading in water due to their extremely low metabolic rate. Immobilized ß-lactamase onto aminosilane magnetic nanoparticles (AMN-MNPs) was used for the degradation of penicillin (PEN). Thermal stability of such immobilized ß-lactamase was investigated, as well as enzyme kinetics of free ß-lactamase and immobilized ß-lactamase was determined. Degradation study of PEN was performed with free and immobilized ß-lactamase and analyzed using HPLC system. The obtained results show that immobilized ß-lactamase has many advantages compared to free ß-lactamase. The immobilized enzyme exhibited hyperactivation of the enzyme, resulting in 107 % residual activity with 100 % immobilization efficiency. Immobilized ß-lactamase showed good thermal stability at various temperatures above 40°C when compared to free ß-lactamase, which was inactivated when exposed to temperatures above 40°C. The results also suggest that the catalytic activity of immobilized ß-lactamase for the degradation of PEN has been significantly enhanced compared to free ß-lactamase, resulting in 98 % degradation of PEN, while only 22 % of PEN was degraded with the free enzyme after 24 hours.