Table 3.

Leucine leaked from scavenger bacteria supporting the cells' growth and mutation

Number of cells per culture at starting time	Number of leu+ revertants in different media
	Time of scavenger bacteria culturing (day)
	0	6 hours	24 hours	48 hours	120 hours	168 hours
2.89 × 105	0	0	0	0	0	0
2.89 × 106	0	0	0	0	0	0
2.89 × 107	0	0	0	1	2	1
2.89 × 108	0	1	1	5	4	5
2.89 × 109	0	2	3	17	21	17
Total revertants	0	3	4	23	27	25
CFUA/culture	2.31 × 105	1.36 × 106	3.54 × 106	8.53 × 106	3.73 × 106	3.02 × 106
CFUB/culture	7.64 × 107	1.69 × 108	3.23 × 108	3.69 × 108	4.46 × 108	4.10 × 108
Leucine (ng/ml)	------	578.7	842.3	971.9	963.2	962.1

A: The number of viable cells of 31343 which were cultured in the medium at 37°C for 24 hours. The initial number of 31343 cells were 2.89 × 10⁵ cells/ml. The medium was MM+P in which the scavenger bacteria cells (in the dialysis tubings) of 35577 were pre-cultured for different days at the concentration of 7.97 × 10⁸ cells/ml. B Same as A except that the initial number of 31343 cells was 2.89 × 10⁸ cells/ml.