Table 1.

Spontaneous induction of λ cI857 S7 prophage in E. coli cells cultivated in media supporting different growth rates

Medium	Growth rate (doublings per hour)	Frequency of spontaneous prophage
		induction (phages per cell)a
LB	1.0	6.6 × 10-7
M9GluCaa	0.8	4.0 × 10-8
M9Glu	0.6	< 1 × 10-9
M9Gly	0.4	< 1 × 10-9
M9Suc	0.3	< 1 × 10-9

^aThe results are average values from three measurements. In all cases, the standard deviation was below 10%