Table 2.

Comparison of β-galactosidase activity in cell lysates and corresponding cell-free supernatants from pneumococcal cultures treated with different peptide pheromones

Pheromone added*	Competence-induced	Cell lysates†	Supernatants†
None	No	634.1  ± 19.6	0.63  ± 0.41
CSP-1	Yes	817.8  ± 26.4	38.4  ± 3.1
CSP-2	No	700.4  ± 22.7	0.26  ± 0.2
SpiP	No	699.2  ± 18.2	0.41  ± 0.2

^*Peptide pheromones were added at a concentration of 250 ng/ml. 

^† β-Galactosidase activities are given in Miller units and are the means ± SEs of triplicate samples.