Characteristics of a soil-isolated Bacillus subtilis phage, GS1, and GS1-mediated plasmid transduction.

A previously described soil-isolated Bacillus subtilis bacteriophage, GS1, was further characterized. It is a tailed phage with regular head morphology and a discrete base plate. GS1 belongs to morphological group A1 of Bacillus phages. Its tail measured 170 nm and the head width was 92 nm. GS1 produced turbid plaques on its natural host strain, but clear plaque variants occurred at high frequency. All attempts to transduce either erythromycin (Em) or tetracycline (Tc) resistance markers, present in soil-isolated phage-sensitive bacilli, failed. Erythromycin resistance plasmid pE194, introduced into B. subtilis by protoplast transformation, was transduced among B. subtilis strains at a frequency of 10(-6) to 10(-7).