Studies on megacinogeny in Bacillus cereus. I. Multiplication of phage wx causing lysogenic conversion to megacin A (phospholipase A) production.

Phage wx capable of reconverting Bacillus cereus strain W derivatives, cured to lose megacin A (phospholipase A) production into megacin A-producing cultures, exhibits unusual kinetics of multiplication; its clear mutant, phage wxc, behaves similarly. The phages are not adsorbed by stationary phase indicator bacteria. As sonicated bacteria fail to inactivate the phages, the absence of adsorption cannot be attributed to an undersurface localization of the receptors. Multiplying bacteria exert a slow and slight degree of phage adsorption. Cells inhibited by chloramphenicol produce no receptors. It has been assumed that the receptor, produced from a precursor involved in bacterial cell synthesis, either absorbs the phage in the nascent state or is incorporated in the cell and loses its phage-adsorbing capacity.