Turnover of putrescine in a Pseudomonas species

A Pseudomonas species was found to readily take up labeled putrescine added in trace amounts to any of four growth media, bis-(3-aminopropyl)-amine, 4-aminobutyrate, glucose-NH(3), and Casamino Acids, although the rate of uptake varied considerably from one medium to another. Putrescine degradation, as well as excretion and conversion to hydroxyputrescine, was demonstrated in all four media, indicating that this organism has a constitutive putrescine degradation pathway. The extents of putrescine degradation, excretion, and conversion to hydroxyputrescine are shown for these four growth media through an incubation period of 1 hr. These results document more fully the experimental details behind a previous communication which postulated that the constitutive degradation of putrescine participates in the regulation of intracellular putrescine concentration. The significance of this apparent violation of the general concept that synthetic end products are normally not degraded is discussed.