sentence: To examine the ability of newly isolated phages to form plaques on alternative hosts seven different strains of R. capsulatus , YW1 [ 34 ] , YW2 [ 34 ] , B6 [ 34 ] , B10 [ 34 ] , St. Louis [ 34 ] , 37B4 [ 49 ] , and Iona ( an isolate of the Beatty lab ) , and two marine Rhodobacteraceae , D. shibae DFL12 and R. pomeroyi DSS3 were used as potential hosts in spot assays with high titer ( > 10 pfu / ml ) lysates .