The effect of inorganic phosphate on cyanogenesis by Pseudomonas aeruginosa

The biosynthesis of hydrogen cyanide (HCN) by a strain of Pseudomonas aeruginosa is found to be significantly influenced by inorganic phosphate. Optimum HCN production occurs when the phosphate concentration is between 1 and 10 mM. Above and below this concentration the amount of HCN produced decreases sharply and at 0.1 and 100 mM phosphate low HCN production occurs. If a culture growing at 0.1 mM phosphate and producing low HCN is shifted to 10 mM phosphate, HCN biosynthesis resumes. Experiments with chloramphenicol indicate that de novo-protein synthesis is required for the process.