Staphylococcus
The Micrococcaceae species most often encountered in the largest numbers in indigenous fermented sausages are different species of Staphylococcus, more specifically S. xylosus, S. saprophyticus and occasionally S. carnosus. Staphylococcus species are thus clearly dominant compared to the Kocuria species sometimes offered, due to their higher salt tolerance and lower oxygen requirements.
Staphylococcus species are facultative anaerobic cocci capable of reducing both nitrate and nitrite and possessing diverse enzymatic activities of major importance for the flavor formation of the fermented dried sausage. More specifically: catalase activity, lipolytic and proteolytic activity, and high capability of degrading amino acids and fatty acids into a wide variety of aroma compounds.
|
Culture |
S. carnosus |
S. xylosus |
Microccaceae spp |
|
Growth temperature optimum/Max/min (°F/°C) |
86/30 |
86/30 |
86/30 |
|
Salt limit (% salt in water) |
16 |
15 |
16 |
|
Fermentable sugars Glucose (dextrose) Fructose Maltose Lactose Sucrose Starch |
+ + - + - - |
+ + + + + - |
+ + - + - - |
Table: Micrococcaceae species offered by Chr. Hansen
Debaryomyces
Yeasts are often associated with indigenous fermented sausages, but species from the genus Debaryomyces, and in particular Debaryomyces hansenii, predominate due to their high salt tolerance.
Hansenii does not reduce nitrate, but decomposes peroxides and consumes both lactic and acetic acids in the sausage thereby increasing pH during the ripening period.
Additionally, D. hansenii produces ammonia, which also increases sausage pH, and possesses lipolytic and proteolytic activities of importance to flavor development. D. hansenii only grows near to the surface of the ripening sausage as it needs oxygen for growth.
Source: Chr.Hansen