Interaction between isolated DNA of phage λ and Escherichia coli spheroplasts treated with sturine

Centrifugation of preparations of spheroplast membranes, treated and untreated with sturine and infected with DNA of phage λ, in a sucrose density gradient (30–55%) showed that sturine treatment of the spheroplasts increases the adsorption of phage DNA by about three times. Under these circumstances, about 50% of the phage DNA molecules absorbed by the spheroplasts are bound with the cytoplasmic membrane of the sturine-treated spheroplasts, and 50% of the DNA molecules are bound with the cell wall of spheroplasts untreated with sturine. It can be concluded from these results that the stimulating effect of sturine in transfection ofE. coli spheroplasts by phage λ DNA is connected with a redistribution of phage DNA absorbed on the spheroplasts from the cell wall to the cytoplasmic membrane, thereby facilitating penetration and attachment of the introduced DNA to the membrane.