Peptide Extracts from Native Lactic Acid Bacteria Generate Ghost Cells and Spheroplasts upon Interaction with Salmonella enterica, as Promising Food Antimicrobials

Table 1

Summary of the various changes that are observed in antibacterial-treated Salmonella cells with Gt2, Cys5-4, and Gt28 peptide extracts.

Peptide/concentration applied (MIC)	Alteration	Brief description
Gt2/1 X MIC	Spheroplasts	Spherical bacteria; changed shape, the inner and outer membranes were intact, but they lost of peptidoglycans.
Gt2/2 X MIC	Spheroplasts	Spherical bacteria; changed shape, the inner and outer membranes were intact, but they lost of peptidoglycans.
	“Ghost’s cells”	The bacterial cells devoid or near-devoid of cytoplasm.
	Filamentation	Bacteria become much larger than normal.
	Intracellular vacuolation	Round-shaped transparent areas present in the bacterial cytoplasm.
Cys5-4/1 X MIC	Spheroplasts	Spherical bacteria; changed shape, the inner and outer membranes were intact, but they lost of peptidoglycans.
Cys5-4/2 X MIC	Filamentation	Bacteria become much larger than normal.
	Intracellular vacuolation	Round-shaped transparent areas present in the bacterial cytoplasm.
Gt28/1 X MIC	Filamentation	Bacteria become much larger than normal.
	Cell envelope layer separation	An increase in the distance between the cytoplasmic membrane and outer membrane of the gram-negative cell envelope.
	“Ghost’s cells”	The bacterial cells devoid or near-devoid of cytoplasm.
	Cell lysis	The cell membrane was damaged leading to leakage.
Gt28/2 X MIC	“Ghost’s cells”	The bacterial cells devoid or near-devoid of cytoplasm.
	Cell envelope layer separation	An increase in the distance between the cytoplasmic membrane and outer membrane of the gram-negative cell envelope.