Effects of microfluidization on kinetic parameter values of lipase hydrolysis reaction

Microfluidic system is a useful alternative for the determination of enzyme kinetic parameter values from minute amounts of pure enzyme and substrate(s) requirement. Lipase reaction was comparatively studied in microfluidic system alongside 1-cm cuvette and cylindrical vessel. Kinetic parameter (Km, kcat, Vmax, kcat/Km) values determined in them were compared. Different geometries of micromixers yielded comparable Km values, representing intermediate values between cuvette and cylindrincal vessel. Comparable values for kcat (≅ Vmax) were obtained for cuvette and cylindrical vessel. kcat (≅ Vmax) values were found to decrease in the micromixers compared to the batch system. Highest specificity kcat/Km was determined in the cuvette system whilst comparable for the rest of studied systems. The observed differences in kinetic parameter values were discussed against prevailing hydrodynamics in the different systems. The findings highlighted important implication in employing different systems to determine enzyme kinetic parameter values.