Occurrence of polyamines in coliphages T5, phiX174 and in phage infected bacteria

The polyamine spermidine and the diamine putrescine have been detected in coliphages T5 and phiX174. Polyamines were identified by thin layer chromatography and mass spectrometry of dansyl derivatives, as well as by ion exchange chromatography. In phiX174 phages, polyamines were sufficient to neutralize 0.5% of DNA phosphates. The polyamine content of T5 phages depended on growth media and purification procedures, but at least 1% of DNA phosphates were neutralized by polyamines. After infection, an increase in cellular polyamine was noticed. This increase paralleled variations in ornithine decarboxylase activity.