Genetic Analysis in Bacillus pumilus by PBS1-Mediated Transduction

Bacteriophage PBS1 mediates generalized transduction in Bacillus pumilus NRRL B-3275 (BpB1). Transduction frequencies for single auxotrophic markers are of the order of 10(-4) transductants per plaque-forming unit in crude phage lysates. The characteristics of PBS1 propagated on BpB1 and the properties of the system of transduction are similar to those reported for PBS1 propagated on Bacillus subtilis. By transduction, eight amino acid auxotrophic markers in BpB1 have been oriented into two linkage groups. One group contains the auxotrophic markers arginine A, leucine, and phenylalanine, and the other group contains the markers lysine, serine, tryptophan, isoleucine-valine, and isoleucine. The nature and relative order of the markers within each linkage group suggest that the arrangement of genes in these areas of the chromosome of BpB1 is similar to the arrangement of phenotypically comparable genes in two linkage groups (defined by PBS1 transduction) in B. subtilis. However, transduction of any of the above cited markers in BpB1 to prototrophy with PBS1 propagated on B. subtilis 168 could not be demonstrated. In addition to BpB1, seven other strains of B. pumilus can be infected with PBS1. Transduction has been demonstrated in three of these strains.