Figure 7. Excess thiamine pyrophosphate production by P. gingivalis.

The E. coli TPP auxotrophic strain JW3957-1 (black shading) and the parent strain JRG902 (white shading) were cultured in M9 growth medium (that lacks thiamine) supplemented with either (a) uninoculated P. gingivalis medium (that lacks thiamine) or (b) cell-free P. gingivalis spent medium. The bacterium was cultured with or without TPP addition (5.88 nM).