Enhanced Kinetic Performance of CLEA-Lipase Extracted from Skim Latex of Hevea brasiliensis upon Immobilization on Magnetic Iron Nanoparticles

Abstract

In this research, lipase recovered from the skim latex of Hevea brasiliensis was immobilized via cross-linked enzyme aggregates (CLEA) technology, while supported by magnetic nanoparticles (MNPs), for properties enhancement. Hybrid immobilization may have affected the kinetic performances of the biocatalysts. The kinetic performance of both MNP supported and unsupported CLEA-lipase, were evaluated based on the Michaelis-Menten model using p-nitrophenyl palmitate as the substrate. Three different linearization model equations were used to compute the kinetic properties, v_max and K_m, and a hyperbolic regression was conducted with computer software. Based on the best fitted model, v_max of MNP-CLEA-lipase, obtained from the Lineweaver-Burk plot (R2=0.9823), was 0.0023 µmol/min.mL, which is higher than CLEA-lipase (0.0015 µmol/min.mL), indicating it needs much higher substrate concentration to saturate the enzymatic sites to reach its maximum velocity. K_m for MNP-CLEA-lipase was 0.4400 µmol, compared to 0.5188 µmol for CLEA-lipase, inferring that it has a higher affinity towards substrates, whereby its rate will approach v_max with lower substrate concentration. Overall, this research demonstrated that wasteful by-products such as skim latex can be converted to useful value-added biocatalyst. A better understanding of the kinetic parameters of this newly produced MNP immobilized biocatalyst is necessary for its further development.