Abstract:

In this study, two strains of Lactobacillus plantarum (L. plantarum) with the highest β-D-glucosidase activity
were obtained from five L. plantarum strains with p-nitro-phenyl-β-D-glucopyranoside as the substrate and their cellular
localization of β-D-glucosidase was studied by using fractional precipitation with differential centrifugation. In addition,
the enzymatic activity of β-D-glucosidase was determined under different growth conditions, followed by analyzing the
growth of L. plantarum. Our results supported the conclusion that β-D-glucosidase was membrane-associated and might be
insoluble. The highest activity was displayed at the late exponential phase and an improved MRS was verified as the optimal
medium. For whole cells, β-D-glucosidase was induced by cellobiose and arbutin, but arbutin played more important role in
the enzymatic activity.

Key words: Lactobacillus plantarum, β-D-glucosidase, cellular localization, enzymatic activity