SP3: a flagellotropic bacteriophage of Bacillus subtilis.

Bacillus subtilis bacteriophage SP3 was shown to be flagellotropic. Mechanical deflagellation of host strain 168wt prevented phage adsorption but adsorption was normal when deflagellated 186wt was allowed sufficient time to regenerate flagella. Two host strains lacking flagella (130 fla- and 19 fla-) did not adsorb SP3. Two host strains with paralysed flagella (38mot- and 13mot-) adsorbed SP3 inefficiently. Revertants of fla- and mot- strains to the motile phenotype adsorbed SP3 normally. A temperature-sensitive host mutant, ts46, with reduced numbers of flagella at 46 degrees C was incapable of efficient SP3 adsorption at this temperature. However, transfection of ts46 by SP3 DNA occurred with virtually identical efficiency at either temperature. Adsorption of a non-flagellotropic phage, SP82, to all bacterial strains used was unaffected by absence of flagella. Isolated flagella adsorbed SP3 inefficiently. Spontaneously non-motile strains of 168wt had lost the ability to support growth of SP3 but SP82 grew normally. Revertants of these strains to the motile phenotype regained the ability to support SP3 growth. Strains derived from surviving bacteria in SP3 lysates of 168wt were non-motile.