Requirements for Pyocyanine Production by Pseudomonas aeruginosa (Schroeter) Migula

SUMMARY: Substances found to be essential for pyocyanine production by Psaulomonas aeruginosa were Mg, PO4, SO4 and NH4 ions, together with a carbon source, preferably glucose, glycerol or ethanol. Ca, Na, K, Fe ions were not essential, nor was asparagine. Pyocyanine was formed in nutrient broth prepared with distilled water; the addition of chalk improved pigment production. Reliable and good yields were regularly obtained on an ordinary broth medium containing glucose (0·2%) and chalk.

Recommended media for stimulating pyocyanine production were tested. Turfitt′s medium gave more reliable pyocyanine formation when the NH4NO3 was replaced by NH4Cl and chalk was added. Increasing the MgSO4. 7H2O content of this medium from 0·25% to 0·2% inhibited pyocyanine production.

Various amino-acids were tested. Glycine, l-tyrosine, dl-alanine, l-leucine, when added separately or in various combinations to a salt mixtureglucose, glycerol or ethanol permitted the production of pyocyanine. A mixture of glycine, l-leucine and dl-alartine (recommended by Burton, Campbell & Eagles, 1947) exerted a stimulating effect on pyocyanine production far superior to that obtained on any other medium tested.

The highest yield reached was 231 mg. pyocyanine/100 ml. of a medium consisting of: 0·4% dl-alanine; 0·8% l-leucine; 0·2% MgSO4. 7H2O; 0·05% K2HPO4; 0·001% FeSO4. 7H2O; 1% glycerol and chalk.