THE AMINO ACID REQUIREMENTS FOR PYOCYANIN PRODUCTION

Abstract

A medium consisting of acid-hydrolysed casein, glycerol, and a salt mixture has been shown to yield pyocyanin by Pseudomonas aeruginosa equal in amount to that obtained from glycerol peptone agar. The monoaminomonocarboxylic acids fraction obtained from casamino acids (Bacto) has been shown to be the source of nitrogen essential to pigment formation. Glycine, dl-alanine, dl-valine, or l-tyrosine have been shown to produce pyocyanin when employed as sole sources of nitrogen. The addition of l-leucine to media containing glycine or dl-alanine markedly increased pyocyanin formation. The addition of dl-phenylalanine to a synthetic medium inhibited pigment production. A synthetic medium consisting of dl-alanine or glycine at 0.4% concentration combined with 0.8% l-leucine, 1.0% glycerol, and a salt mixture has been shown to be the most suitable medium for pyocyanin production by five representative strains of Pseudomonas aeruginosa.