Activatory Effect of Germination on Catalytic Capacity of Urease Extracted from Beans Samples (Effect of Germination on the Kinetics of Urease from Beans)

Aim: This research work was designed to determine the effect of germination on catalytic capacity of urease extracted from seven beans samples.

Study Design: Experimental.

Place and Duration: Department of Biochemistry, School of Science and Science Education, Federal University of Technology, Minna, Nigeria, between December, 2010 and September, 2011.

Methodology: Seven samples of beans namely; Phaseolus lunatus, Parchyrhizus tuberrosus, Glycine max, Cajanus cajan, Mucuna pruriens, Kerstings geocarpa and Vigna mungo were used by comparing urease activity in germinated to ungerminated beans samples.

Result: The protein level in germinated and ungerminated beans samples as well as, optimum pH, optimum temperature, substrate concentration and kinetic parameters, Vmax, Km, and Vmax/Km of urease were determined. The pH, temperature and substrate concentration ranged from 5.50-8.0, 30-80ºC and 0.1-0.6M respectively. From the results, the protein level in germinated beans samples reduced significantly (p<0.05) compared to ungerminated beans samples. The optimum pH and temperature ranged from 6.5-7.0 and 60-70ºC respectively for both germinated and ungerminated beans sample. Therefore, germination did not affect the pH and temperature stability of urease when compared to ungerminated beans samples. The results showed that germination significantly (p=0.05) increased Vmax and there was no significant (p=0.05) difference in Km of urease in germinated and ungerminated beans sample studied. However, the catalytic capacity (Vmax/Km) of urease in germinated beans was significantly (p=0.05) higher than ungerminated.

Conclusion: This implies that, with germination urease activity can be increased to meet both application of urea as fertilizer (agriculture), clinical analysis of urea in biological fluid, artificial kidney development and other applications.