Fig 5. De-chaining activity of recLytB.

Aliquots from cultures of S. gordonii V288 and ΔlytB mutant GP1485 were collected at the following OD₅₉₀ values: 0.2, 0.8, 1.9 and ~1.7 (ON) (since the growth curves of the two strains were essentially indistinguishable (see Fig 1), same OD₅₉₀ values corresponded to the same time points). Cells were washed, resuspended in buffer Tris 50 mM pH 7.0, and incubated with or without recLytB at 37°C. V288 without recLytB (white bar), GP1485 without recLytB (black bar), GP1485 with 0.2 μg μl^-1 of recLytB (gray bar). After 6 hours of incubation, bacteria were observed by light microscopy to count the number of chain-forming bacteria. Data are expressed as the mean ± SEM of the number of cells forming a chain (mean chain length) in at least three microscopy fields. The asterisks indicate *P < 0.05 and ***P < 0.001. Data from one representative experiment (of two independent experiments) are shown.