Figure 2. Sucrose-dependent adhesion to a glass surface with co-culture of S. mutans isogenic mutants and other oral streptococci. S. mutans MT8148 (D) and its isogenic mutants (A–C) were co-cultured with other oral streptococci at a total inoculum volume of 60 µL, with various volumes of each bacterial suspension in 6-µL increments. BHI medium containing 1.0% sucrose was added to make the total volume 3.0 mL. The following strains were used for mixed cultures: S. sanguinis ATCC10556, S. oralis ATCC10557, S. gordonii ATCC10558, S. anginosus FW73, and S. mitis SK142. Sucrose-dependent adhesion of the organisms to smooth surfaces was determined as described in MATERIALS & METHODS. The results with transformant B42-10 were nearly the same as those with mutant B72, as shown in panel A.