Mycosides C: behavior as receptor site substance for mycobacteriophage D4

Interpretation of an earlier published infrared spectrum of Mycobacterium smegmatis lipids with receptor site activity for D4 phage led us to the inference that the active substance is very likely a mycoside C. This hypothesis was confirmed: the well-characterized mycosides C(s) and C(1217) elaborated by the heterologous strains M. scrofulaceum and Mycobacterium species 1217, respectively, are essentially indistinguishable from the smegmatis lipids in their behavior toward D4. Minute quantities adsorb and extensively inactivate the phage on appropriate incubations. In accord with derivative expectations, Mycobacterium species 1217 is a permissive host, attacked and lysed by D4. However, our current strains of M. butyricum, M. avium, and M. scrofulaceum, which reputedly produce various related mycosides C, are neither lysed by nor do they significantly adsorb the phage. Implications of these observations are discussed.