HOURS 



Fig. 12.4 — Growth curves of suppressor strains in absence and presence of the sulfonamide-requiring gene (sfo) 

 at 35° and 25° on minimal medium (light Hne), 10"* M />-aminobenzoic acid (line of open circles — PABA), and 



2 X 10"" M sulfanilamide (dotted line -SA). 



