TABLE 2.

Transient loss of colony-forming ability is corrected by the presence of exogenous amino acids^a

Time of platingb	CFU/ml on:
	SMMc	SMM+CH+Trpd	TBAB
Prior to dilution	2 × 108	7 × 108	6 × 108
0 min after dilution	3 × 107	6 × 107	7 × 107
30 min after dilution	6 × 105	6 × 107	8 × 107
60 min after dilution	1 × 104	8 × 107	1 × 108
90 min after dilution	1 × 105	1 × 108	2 × 108
120 min after dilution	5 × 107	4 × 108	5 × 108

^aStrain YB955 was incubated with aeration (as described in the text) in GM1 (4) until 90 min following the cessation of exponential growth. At that point, the cells were diluted 1/10 into GM2. The experiments were repeated three times, and the results are representative. The cells were plated onto the three types of solid media prior to dilution into GM2 or at different time points after dilution. Once the cells were diluted into GM2, the incubation continued at 37°C with aeration. 

^bSMM, Spizizen minimal medium containing the amino acids needed to complement the auxotrophic requirements of the strain (i.e., His, Met, and Leu). 

^cSMM+CH+Trp, SMM to which casein hydrolysate (0.1%) and tryptophan (50 μg/ml) were added.