[Characteristics of a new cyanophage lysing unicellular cyanobacteria of the genus Synechococcus].

A new cyanophage S-2L growing on three strains of the cyanobacterium belonging to the Synechococcus genus has been isolated. The cyanophage has an icosahedral head, 56 nm in diameter, and flexible tail with a non-contracting sheath, 120 nm long. Over 95 per cent of the cyanophage particles are adsorbed within 10 min, the rate constant of adsorption being 3.2-10(-9) ml/min. The latent period lasts 5 hours, the yield is 100 particles per cell. The intracellular growth is characterized by the accumulation of the cyanophage particles at the poles of the cell. The photosynthetic lamellae remain intact up to the beginning of lysis which consists in local disruptions of the cell envelope.