A Virus of Blue‐green Algae From Freshwater Habitats in Scotland

Summary A virus which is pathogenic to certain blue‐green algae belonging to the genera Plectonema, Phormidium and Lyngbya has been isolated from a variety of freshwater habitats in Scotland and has been detected over a 12‐month period in one of these habitats. The virus (D‐1) is a cyanophage, has an isohedral head and a short tail and is morphologically and serologically related to the LPP‐1 virus isolated from the United States and the GIII virus isolated from Israel by other workers. The partially purified virus has an absorption spectrum characteristic of a nucleoprotein with a maximum at 260 nm and a minimum at 243 nm. D‐1 is temperature sensitive being inactivated on heating at 60°C for 6 minutes. Its multiplication rate is fast, increasing from an initial titre of 103 to 1012PFU/ml within 40 hours. The lysis of the host cell results in a rapid loss of the phycobilin and chlorophyll pigments.