Adjective
phagosomal (not comparable)
Of or pertaining to a phagosome.
It is important to note that the cyanobacterial endosymbiont already had a double membrane—the phagosomal vacuole -derived membrane was lost. Source: Internet
It used to be widely assumed that the inner membrane is the original membrane of the once independent prokaryote, while the outer one is the food vacuole (phagosomal membrane) it was enclosed in initially. Source: Internet
Euglenophyte chloroplasts have three membranes—it is thought that the membrane of the primary endosymbiont was lost, leaving the cyanobacterial membranes, and the secondary host's phagosomal membrane. Source: Internet
The two additional membranes are thought to correspond to the plasma membrane of the engulfed alga and the phagosomal membrane of the host cell. Source: Internet