How to Propionibacterium freudenreichii

What You Need to Know

Propionibacterium freudenreichii is a gram-positive, non-motile bacterium that plays an important role in the creation of Emmental cheese, and to some extent, Jarlsberg cheese, Leerdammer and Maasdam cheese. Its concentration in Swiss-type cheeses is higher than in any other cheese. Propionibacteria are commonly found in milk and dairy products, though they have also been extracted from soil. P. freudenreichii has a circular chromosome about 2.5 Mb long. When Emmental cheese is being produced, P. freudenreichii ferments lactate to form acetate, propionate, and carbon dioxide: (3 C3H6O3 → 2 C2H5CO2 + C2H3O2 + CO2).

Key Parameters

Steps

1. 1.

   Emmental cheese (Switzerland): Creates characteristic nutty flavor and eye formation

2. 2.

   Jarlsberg cheese (Norway): Develops mild, sweet flavor profile

3. 3.

   Leerdammer cheese (Netherlands): Contributes to semi-hard texture and mild taste

The Science

Primary Reaction

Lactic acid fermentation

Common Mistakes