Uricase Kinetic Determination of Bacillus subtilis, B. megaterium, and B. cereus Cells

Abstract

Uric acid concentration could be determined based on the oxidation of uric acid into alantoin with the presence of uricase. Determination is needed to diagnose the occurrence of kidney disease in gout patients. This research used uricase cells derived from Bacillus subtilis, B. megaterium, and B. cereus to study their kinetics using spectrophotometry method to measures the decrease of uric acid absorbance at 293 nm. The optimum conditions of uricase activity from the three bacterial cells occured in physiological conditions and uricase activity was stable until the second day. The values of maximum velocity (Vmax) for B. subtilis, B. megaterium, and B. cereus were 0.0853, 0.0824, and 0.0412 mM/min, respectively. The values of Michaelis-Menten constant (Km) for B. subtilis, B. megaterium and B. cereus were 0.0029, 0.0036, and 0.0036 mM, respectively. The value of catalytic constant (kkat) for B. subtilis, B. megaterium, and B. cereus were 266.4109, 171.6797, and 257.6257 mM/min mL OD=1, respectively. Based on these results that the most powerful bacteria bind the substrate was B. subtilis with the least Km value, and the highest Vmax and kkat.