Novel Virus on Filamentous Arthronema africanum Cyanobacterium.

Widely distributed in water environments and in soil, cyanobacteria are hosts of lysogenic or lytic bacterioviruses. A novel, probably lysogenic virus (phage) for which the name Arthronema africanum virus TR020 (Aa-TR020) is proposed, has been isolated from filamentous freshwater cyanobacterium Arthronema africanum. The virus formed turbid plaques on plate culture of A. africanum strain 1980/01 but not on other Arthronema strain and other bacterial species. The genome of Aa-TR020 is linear molecule of dsDNA, 44,805 bp in length with 216 bp long terminal repeats and with G + C content of 46%. Fifty-five genes organized on plus and minus strands were predicted there. The genome size, gene arrangement, and selected protein sequences showed relatedness to Phormidium virus Pf-WMP3 and other viruses known to infect cyanobacteria and classified in the family Podoviridae.