Assembly of the enveloped bacteriophage phi 6 in environments which perturb the host cell membranes

The effects of known membrane-perturbing agents (pH, Na+, Ca2+, and a small lipid-soluble molecule) on the enveloped bacteriophage phi 6 host cell system were investigated at the levels of cellular growth, virus assembly and stability, and the physical and chemical properties of host cell membranes. Spin-label probes of cellular membranes indicate that growth in high levels of Na+ or the small spherical hydrophobic molecule adamantanone results in membranes having increased "fluidity," while growth in high levels of Ca2+ results in slightly greater rigidity of the membranes. In addition, the phospholipid composition of the cellular membranes is dependent on the NaCl concentration in the growth medium. None of these membrane alterations, however, prevent the production of infectious phi 6 virus particles.