Peptone Water, buffered, 1 l, 10 x 100 ml

Buffered peptone water is a non-selective medium recommended as a preenrichtment medium by EN ISO 6579 normative in food samples containing suspected contaminants such as Salmonella and in ISO 22964 in milk and milk products for Enterobacter sakazakii.

This broth is rich in nutrients and produces high resuscitation rates for sublethally injured bacteria and intense growth.
Changes in pH my cause damages to bacteria growth. Buffered peptone water maintains a high pH over the enrichment period via the posphate buffer system and allows repair of injured cells sensitive to low pH.
Pancreatic digest of casein provides nitrogen, vitamins, minerals and amino acids essential for growth. Sodium pyruvate can be added as an additional source of energy, but may also have protective effects against hydrogen peroxide that aids in the resuscitation of stressed organisms. Sodium chloride supplies essentials electrolytes for transport and osmotic balance.