Characterization of SPβ: a temperate bacteriophage from Bacillus subtilis 168M

Abstract
Bacillus subtilis 168M is lysogenic for a temperate bacteriophage called SPβ. The virus head is 76 m wide by 82 m long and the tail measures 12 by 358 m. The DNA molecular weight is 62 million. SPβ is spontaneously released at low levels in cultures of B. subtilis 168M, and can be induced at higher levels by treatment with mitomycin C or N-methyl-N′-nitro-N-nitroso-guanidine.