Cyanobacterial blooms are a growing concern in the Pacific Northwest because of their
threat to watershed health and drinking water supplies. Bacteriophages are pathogens of
bacteria and may contribute to the growth and decline of seasonal blooms. Bacteriophage
S-CRM01, a lytic T4-type myophage, has been isolated from a freshwater strain of
Synechococcus (Dreher et al., 2011). This phage was isolated from a cyanobacterial
bloom of primarily toxic Microcystis aeruginosa, but an endemic Synechococcus lineage,
that was a minor constituent of the bloom, is the actual host for this phage. This survey
was conducted to assess the distribution of phage S-CRM01 in Oregon and Northern
California in bodies of water with cyanobacterial blooms. On the basis of PCR
identification of plaques on LC16 cyanobacteria plates, S-CRM01 was present across a
length of about 250 km along the Klamath River valley, from the Williamson River Delta
at the northern end of Upper Klamath Lake as far downstream as Seiad Valley in 2009.
Although this phage has not been shown to infect toxic cyanobacteria, it is still valuable
in the freshwater phage community where few genomes have been sequenced