Phospho-β-glucosidases and β-Glucoside Permeases in Streptococcus, Bacillus , and Staphylococcus

Abstract

The presence of phospho-β-glucosidases and β-glucoside permeases was found in strains of Streptococcus, Bacillus, and Staphylococcus. In streptococci, the phospho-β-glucosidase activity depends on the antigenic group. The highest activity was found in strains of group D. In group D strains, phospho-β-glucosidase activity is induced by β-methyl glucoside and cellobiose but not by thiophenyl β-glucoside (TPG). With the exception of four strains isolated in Japan, all strains of B. subtilis tested possess an inducible phospho-β-glucosidase activity, β-methyl glucoside, cellobiose, and TPG acting as inducers. S. aureus strains possess phospho-β-glucosidase A but not phospho-β-glucosidase B, whereas most S. albus strains show no detectable phospho-β-glucosidase activity. The prompt fermentation of β-methyl glucoside by S. aureus strains could serve as an additional criterion for their differentiation from S. albus. A comparative investigation of the active uptake of ¹⁴C-TPG showed that a Streptococcus group D strain and a B. subtilis strain posses two inducible permeases with characteristics similar to the β-glucoside permeases I and II of Enterobacteriaceae. In S. aureus, TPG is accumulated by a constitutive permease with high affinity for aromatic β-glucosides and glucose. The active uptake of TPG by S. aureus appears to depend on the activity of the phosphoenol pyruvate-dependent phosphotransferase system.