Colicins are not transiently accumulated in the periplasmic space before release from colicinogenic cells

Abstract
Colicins are released into the spent medium from colicinogenic cells. The pathway of release was investigated. The localization in producing cells of colicins A, E3 and of cloacin DF13 was determined at various times after mitomycin C addition. No transient accumulation in the periplasmic space of colicinogenic E. coli K12 strains was detected by EM for any of the bacteriocins tested. Asynchronous induction in individual cells was detected for each bacteriocin tested. Apparently colicins, as well as cloacin DF13, do not transit through the periplasmic space before release from colicinogenic cells.