Table 3. Relative sensitivities to J1 phage infection among MNNG-induced J1 phage-resistant mutants.

		Relative J1 phage sensitivity
		Plasmid
Strain		–	/pYCAT	/pYCAT-asnH
L. casei	ATCC 27139	1.0	NT	NT
	MT77	4.4×10−5	4.9×10−5	1.1
	J1R	1.2×10−4	3.0×10−4	0.8
	J1R2	1.1×10−4	1.4×10−4	1.1
	J1R3	1.1×10−4	2.1×10−4	1.1
	J1R4	1.4×10−4	8.4×10−5	0.8

The relative sensitivities to J1 phage were assessed as the ratio of PFU for MNNG-induced mutants to that of the wild-type strain. NT, not tested.