title: Isolation and characterization of a bacteriophage specific for Sphaerotilus natans which contain an unusual base in its deoxyribonucleic acid.
abstract: A bacteriophage was isolated specific for Sphaerotilus natans, an organism for which bacteriophages have not been previously described. This phage (designated SN1) was found to infect both the single-cell (S-type) and filamentous (R-type) forms of the host, although the sheath appeared to provide R-type cells with a degree of physical protection from infection. SN1 had a hexagonal head and a long flexible tail resembling most closely the phages in Bradley's group B. The nucleic acid was found to be deoxyribonucleic acid and contained an unusual base which substituted for 35% of the guanine. Deoxyribonucleic acid base composition was 56% cytosine plus guanine.
mesh_terms: D000327:Adsorption; D001435:Bacteriophages / Q000254:growth & development / Q000302:isolation & purification* / Q000648:ultrastructure; D001483:Base Sequence; D003596:Cytosine / Q000032:analysis; D004279:DNA, Viral / Q000032:analysis*; D006088:Gram-Negative Aerobic Bacteria; D006147:Guanine / Q000032:analysis; D012722:Sewage; D014779:Virus Replication; D014871:Water Microbiology; D014876:Water Pollution / Q000517:prevention & control*
chemical_list: D004279:DNA, Viral; D012722:Sewage; D006147:Guanine; D003596:Cytosine