After the recognition period, it becomes irreversibly attached via the pole opposite the flagellum. Once inside the periplasm, the "Bdellovibrio" cell seals the membrane hole and converts the host cell to a spherical morphology, this is due to secretion of L,D transpeptidases which breaks the peptidoglycan apart, and therefore causes the cell to become amorphous. The two-cell complex formed is called a bdelloplast. The "Bdellovibrio" cell uses hydrolytic enzymes to break down the host cell molecules, which it uses to grow filamentously. When the host cell nutrients are exhausted, the filament septates to form progeny "Bdellovibrios". The progeny become motile before they lyse the host cell and are released into the environment. The entire life cycle takes three to four hours, and produces an average of 3–6 progeny cells from a single "E. coli", or up to 90 from larger prey such as filamentous "E. coli".