Production of Cell Membrane-Bound α- and β-Glucosidase by Lactobacillus acidophilus
2012
Mahajan, P. M. | Desai, K. M. | Lele, S. S.
Hydrolytic enzymes, viz. α- and β-glucosidase, were produced from indigenous isolate, Lactobacillus acidophilus, isolated from fermented Eleusine coracana. Production of these enzymes was enhanced by optimizing media using one factor at a time followed by response surface methodology. The optimized media resulted in a 2.5- and 2.1-fold increase in α- and β-glucosidase production compared with their production in basal MRS medium. Localization studies indicated 80% of the total activity to be present in the cell membrane-bound fraction. Lack of sufficient release of these enzymes using various physical, chemical, and enzymatic methods confirmed their unique characteristic of being tightly cell membrane bound. Enzyme characterization revealed that both α- and β-glucosidase exhibited optimum catalytic activity at 50 °C and pH 6.0 and 5.0, respectively. K m and V max of α-glucosidase were 4.31 mM and 149 μmol min−1 mL−1 for p-nitrophenyl-α-D: -glucopyranoside as substrate and 3.8 mM and 120 μmol min−1 mL−1 for β-glucosidase using p-nitrophenyl-β-D: -glucopyranoside as the substrate.
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