A method for recombinantly expressing a macromolecule in a host cell is disclosed which involves culturing a host cell which contains two nucleic acid sequences, i.e., a first nucleic acid sequence encoding a membrane-permeabilizing agent and a second nucleic acid sequence encoding a desired macromolecule under the operative control of an inducible promoter, to a selected cell density that permits accumulation of the agent. Thereafter the host cell is exposed to an environmental condition that induces the agent to disrupt the integrity of the cell membrane without complete lysis of the cell membrane. The host cell thereby allows transport through the membrane of small molecular weight compounds. These resulting host cells are cultured in the presence of a nutrient cocktail that contains components that can transport through the disrupted cell membrane, e.g., an inducing agent that induces the tightly regulated promoter and metabolic requirements that permit expression of the macromolecule.