Extracellular deoxyribonuclease activity of Pseudomonas aeruginosa.

Pseudomonas aeruginosa cultured on deoxyribonucleic acid (DNA) media containing Nissan's heart extract or chicken heart extract could produce extracellular deoxyribonuclease, while on other DNA media with heart extracts from cow, pig and mouse could not. Variation in the kind of peptones in the DNA media did not make significant difference in this activity, although some peptones caused cloudiness of the media. P. aeruginosa did not need cation activators of chloride compounds to produce extracellular deoxyribonuclease. On the modified Eiken's DNA medium, gram negative bacilli other than P. aeruginosa and Serratia marcescens, i.e. Klebsiella, Salmonella, Shigella, Escherichia coli and Alcaligenes did not produce deoxyribonuclease. The production of extracellular deoxyribonuclease activity on the modified Eiken's DNA medium can be used as a supporting test for biochemical identification of P. aeruginosa.