Figure 5

Functional dispaly of beta-galactosidase (A) and two proteins simultaneously (B) on the LAB cells. (A) PBS, Gal and Gal-LcsB were added to equal amounts of L. lactis, Lb. crispatus, Lb. brevis, Lb. delbrueckii and Lb. helveticus, respectively. After the binding experiment, the surface-exposed beta-galactosidase activities of various LAB cells were measured. (B) The samples which contained GFP-LcsB and Gal-LcsB fusion proteins at different ratio were added to the cells of L. brevis and fluorescence intenstiy and enzymatic activity were measured. Bar A, incubation with 1 volume of cell-free culture supernatant containing GFP-LcsB; bar B, incubation with 1 volume of cell-free culture supernatant containing 4/5 GFP-LcsB and 1/5 volume of Gal-LcsB; bar C, incubation with 1 volume of cell-free culture supernatant containing 3/5 GFP-LcsB and 2/5 volume of Gal-LcsB; bar D, incubation with 1 volume of cell-free culture supernatant containing 2/5 GFP-LcsB and 3/5 volume of Gal-LcsB; bar E, incubation with 1 volume of cell-free culture supernatant containing GFP-LcsB 1/5 and 4/5 volume of Gal-LcsB; bar F, incubation with 1 volume of cell-free culture supernatant containing Gal-LcsB. The mean value for three determinations was normalized to the activities for samples A and B, which were defined as 100%.