Fig. 1

Identification of Pseudanabaena sp. Chao 1811 and five cyanophages. A The image of Pseudanabaena sp. Chao 1811 photographed by inverted optical microscopy. It possesses a typical morphology similar to those previously reported Pseudanabaena strains [14]: (1) cell division in one plane and intercellular breakage of trichome (filament); (2) straight trichomes composed of multiple barrel-shaped cells; (3) cells with a length bigger than the diameter; (4) cell walls constricted at the cell junction. The scale bar is 10 μm. B–F Negative-staining images of the purified Pan1~Pan5 particles under a 120 kV transmission electron microscope. Pan1 has a prolate icosahedral head of 94 nm in length and 58 nm in width, whereas Pan2~Pan5 all possess a classic icosahedral head of about 60~70 nm in diameter. Except for the short-tailed Pan3, Pan1, 2, 4 and 5 have a long and flexible tail in length of 144, 210, 100 and 149 nm, respectively