FACTORS INFLUENCING PIGMENT PRODUCTION IN A MUTANT STRAIN OF SERRATIA MARCESCENS

Abstract

A white mutant (254) which accumulates indole when grown on a defined medium will develop the characteristic red pigment of Serratia if L-tryptophan is added to the medium, in which case indole is not detected in the medium. In the presence of glycine, mutant 254 will develop red pigment slowly but the pigmentation is less intense than that induced by the addition of tryptophan. Mutant 254 will develop red pigment when grown adjacent to another color mutant of Serratia and white mutants have been isolated which will form pigment when grown with mutant 254. On the basis of these interactions a schema relating the position of mutants causing a block in pigment synthesis has been presented.