FIG. 3.

S. gordonii exhibits maximum induction of AI-2 production in THBS. Time courses of culture densities (A) and AI-2 induction levels (B) of wild-type (WT; open circles), luxS mutant (open squares), and complemented (Comp) luxS mutant (open triangles) S. gordonii strains grown in THBS are shown. Culture densities and AI-2 induction levels of the wild-type strain grown in THB lacking serum (dotted lines, no symbols) and in TY-glucose medium (filled diamonds) are also shown. All time course experiments were repeated at least six times, and the averages of three representative independent experiments with standard deviations are shown (B). KU, Klett units.