Figure 1.

Transmission electron micrographs of negative-stained bacteriophages present in the Methylomirabilis bioreactor enrichment culture. Four viral morphotypes were observed. (A) Viral morphotype with putative icosahedral symmetry of the head (~71 nm diameter), without a tail or other appendages but with a central round internal core (~25 nm diameter, see arrows). (B–D) Three additional viral morphotypes all with a tail and a putative icosahedral symmetry of the head (~87, ~50, and ~41 nm diameter respectively). Scale bars; 50 nm.