Fig. 1

Effect of growth medium on the formation of β-galactosidase and α-galactosidase activities in whole cells of G. dipsosauri strain DD1. Bacteria were grown to exponential phase in tryptic soy broth containing 1.0 mol l⁻¹ KCl (TSB), tryptic soy broth without dextrose containing 1.0 mol l⁻¹ KCl (TSB-d), tryptic soy broth without dextrose containing 1.0 mol l⁻¹ KCl and 0.5% (w/v) D-glucose (TSB-d + Glc), tryptic soy broth without dextrose containing 1.0 mol l⁻¹ KCl and 0.5% (w/v) D-galactose (TSB-d + Gal), tryptic soy broth without dextrose containing 1.0 mol l⁻¹ KCl and 0.5% (w/v) lactose (TSB-d + Lac), tryptic soy broth without dextrose containing 1.0 mol l⁻¹ KCl and 0.5% (w/v) D-melibiose (TSB-d + Mel), tryptic soy broth without dextrose containing 1.0 mol l⁻¹ KCl and 0.5% (w/v) D-raffinose (TSB-d + Raf), or tryptic soy broth without dextrose containing 1.0 mol l⁻¹ KCl and 0.5% (v/v) glycerol (TSB-d + Gly). Bacteria were harvested, washed with 0.85% NaCl, resuspended in 0.85% NaCl to give a suspension with 100 Klett Units, frozen, and thawed. Cells were treated with 0.005% Triton X-100 prior to enzyme assays with β-ONPG as the substrate for β-galactosidase activity (light bars) or with α-PNPG as the substrate for α-galactosidase activity (dark bars). Data show the means and standard deviations of assays from one of several experiments