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Have you always thought that bacteria were dangerous, harmful and can kill you! Well, you’d be surprised to know that certain bacteria actually live within our bodies and can greatly benefit our health. Furthermore, certain strains of bacteria can be very useful, aiding in pharmaceutical research, cosmetics, environmental remediation and one of the most important processes of them all, fermentation.
In order to prepare fermented meats such as sausages and salami, specific steps are required. First the meat is ground in order to get the desired texture. Flavourings, salts, and other spices are then added and mixed into the meat. The meat is then packed, and starter cultures of bacteria are added to the meat. One of the bacteria used, known as Staphylococcus carnosus plays an important role in the fermentation of meat as it adds flavour to the meat, preserves the meat, and adds texture to the meat.
Staphylococcus carnosus (S. carnosus) is a gram-positive species of bacteria that belongs to the genus Staphylococcus and is found in various environments such as in soil, in water, and in the mucous membranes/skins of certain animals. Its cells are spherical in shape and are arranged in grape like clusters (staphylococcus). S. carnosus is also a facultative anaerobe and can therefore live in the presence/absence of oxygen.
This occurs as the lipases break down triglycerides into free fatty acids while the proteases break down proteins into peptides and amino acids resulting in a more textured and distinctly tasting meat (Fatty due to the free fatty acids and savoury due to the amino acids/peptides).
("Staphylococcus Carnosus - an overview | ScienceDirect Topics")
Although the organism S. carnosus does not produce toxins, under certain conditions it has a low probability of producing harmful metabolites. Cross contamination as well as poor sanitation protocols could cause S. carnosus to spread to other food manufacturing processes resulting in health risks. It is therefore important to maintain proper hygiene while working with microorganisms despite the microorganism being “safe” under certain conditions.
It is also important to note that although the species S. carnosus is safe to use in the fermentation process, other strains within the genus Staphylococcus can be very harmful. You should therefore be able to distinguish between coagulase positive Staphylococci (harmful Staphylococci) and coagulase negative Staphylococci (“safe” Staphylococci).
https://www.sciencedirect.com/science/article/abs/pii/S0168160508003954
https://www.sciencedirect.com/science/article/abs/pii/S0956713516300433
S. carnosus is able to convert the sugars present in meat into lactic acid due to the production of certain enzymes such as lactase. This results in lower Ph levels, producing a tangy flavour. S. carnosus also alters the fatty acid complex of the meat due to the production of lipases and proteases.
("Staphylococcus carnosus: from starter culture to protein engineering platform - PubMed (nih.gov)")
