Stabilization and reutilization ofBacillus megaterium glucose dehydrogenase by immobilization.
June 27th, 2008 | by admin |Stabilization and reutilization ofBacillus megaterium glucose dehydrogenase by immobilization.
Glucose dehydrogenase (GDH) fromBacillus megaterium was immobilized using aminopropyl controlled-pore silica (CPS, average pore sizes of 170 and 500 A) as a support and glutaraldehyde as a bifunctional crosslinking agent. The CPS-immobilized enzyme could be reused 12 times and the best results were obtained using aminopropyl CPS-500 and bovine serum albumin as a feeder for stabilizing the protein layer on the support. DEAE-Sephadex (A-25 and A-50) was also used as a support for immobilizing GDH, with yields of around 42% for A-25 and 25-30% for A-50. The effect of pH on the immobilization procedure showed pH 6.5 to be better than pH 7.5 with respect to the recovery of enzyme activity. Both preparations of DEAE-Sephadex immobilized GDH could be reused several times and were thermostable at 40 degrees C for 7 h. The kinetic parameters as Michaelis constant and maximum rate were determined for the immobilized enzyme and compared with those for the freeform.
Baron M, Fontana JD, Guimarães MF, Woodward J.
Biomass Chemo/Biotechnology Laboratory, Department of Biochemistry, Federal University of Paraná, P. O. Box 19046, 81531-970, Curitiba, PR, Brazil.