TABLE 3.

Permeability coefficients of the outer membranes

Strain	Permeability coefficient (cm s−1)
	Cefazolin	Cephaloridine	Cefotaxime
98R mutant	3.7 × 10−5	5.7 × 10−5	4.4 × 10−7
520R mutant	0.7 × 10−5	1.3 × 10−5	7.5 × 10−8