TABLE 4.

Protease activity of S. gordonii Challis by azocasein assays^a

S. gordonii strain	OD420b
	Cell pellet	Supernatant
Challis	0.174 ± 0.055	0.452 ± 0.044
41A9	0.011 ± 0.034	0.255 ± 0.016
BYW1	0.103 ± 0.031	0.233 ± 0.013

^aThe cell pellets and supernatant fluids were from cultures of S. gordonii Challis grown overnight in THB. The supernatant fluids were concentrated as described in Materials and Methods. All of the cell pellets and the concentrated supernatant fluids from 50-ml cultures were utilized in the assays.

^bValues are means ± standard deviations from three experiments.