Lipopolysaccharides

Lipopolysaccharides (LPS) are complexes of polysaccharide (O-antigen, core) and lipid A forming the outer leaflet of the outer membrane of Gram-negative bacteria — key determinants of serological antigenicity and toxicity. Known as endotoxins, they are released when cells lyse and trigger strong immune responses — fever, inflammation, septic shock — in humans and animals. In food safety their presence signals Gram-negative contamination or biofilms, and sensitive assays (Limulus amoebocyte lysate, LAL) detect them in water, injectable-grade ingredients, infant formula plants and processing environments; controlling them means controlling Gram-negative growth through sanitation and process hygiene.