Thiamine stimulates the production of a red pigment , which is chromatographically and spectrophotometrically identical to prodigiosin , by growing cultures of serratia marcescens mutant 9-3-3 . this mutant is blocked in the formation of 2- methyl -3- amyl pyrorol( MAP),the monopyrrole moiety of prodigiosin , but accumulates 4-methoxy-2, 2-bipyrrole -5- carboxaldehyde (MBC) and can couple this compound with( MAP) to form prodigiosin . Addition of thiamine caused production of( MAP) , and as little as 0.02 mg of thiamine / ml in peptone- glycerol medium stimulated production of measurable amounts of prodigiosin. Phosphate saltes and another type of peptone decreased the thiamine- induced formation of prodigiosin ,yeast extract and glycerol enhanced formation of this substance. Thiamine also enhanced production of prodigiosin by wiled – type Strain Nima of S. marcescens . The pyrimidine moiety of thiamine was also 10% as effective as the vitamin ; the thiazol moiety only 4% , and the two moieties together , 25% . Thiamine did not stimulate production of prodigiosin biosynthesis as strain 9-3-3 . This is not surprising since strain 9-3-3 originated as a result of two mutational events one event may involve thiamine directly , and the other may involve the biosynthesis of( MAP).
