Invisible battle between bacteria determines the flavour and safety of salami
VUB-research could lead to safer products, more consistent quality, and potentially new flavours and textures.
Fermentation is one of the oldest methods of preserving food. Long before refrigerators existed, people relied on microorganisms to keep food – including meat – safe to eat. PhD research by VUB researcher Ana Sosa Fajardo (VUB Research Group of Industrial Microbiology and Food Biotechnology) now sheds light on why a fermented sausage, for instance, is not only safe to eat but also enjoyable in terms of flavour. According to the researcher, an invisible battle unfolds between bacteria during the fermentation process. Her PhD research shows how certain bacteria compete with one another or cooperate, and adapt in ways that ultimately ensure the flavour, colour and safety of fermented meat.
The fermentation process plays an important role in the production of cured meat products such as salami and other fermented meats. Yet we still do not fully understand exactly what happens during that process. “For fermentation to be successful, bacteria are constantly interacting with one another,” says Sosa Fajardo. “They have to adapt to a challenging and continuously changing environment. Some bacteria produce substances that inhibit competitors, while others become more efficient at taking up nutrients or protecting themselves against stress.”
Within this complex microbial community, two groups of bacteria play a key role. Lactic acid bacteria ensure that the product becomes more acidic, reducing opportunities for harmful microorganisms to thrive. A second group of bacteria mainly helps to develop flavour and colour. Until now, much less was known about this latter group.
For her PhD research, Sosa Fajardo focused on one particular bacterium: Staphylococcus shinii. Although the name may not sound familiar, the bacterium may play an important role during fermentation processes. Using advanced techniques, the researcher investigated not only the genetic properties of the bacterium, but above all which of these characteristics actually become active during the production of fermented meat.
What takes place within a piece of fermented meat turns out to be far more complex than it appears at first sight: inside the meat exists a microscopic society in which billions of bacteria are invisibly negotiating for dominance. “Competitive factors are essential for the survival of bacteria within a community,” says Sosa Fajardo. “At the same time, however, they can also determine the quality and safety of the final product.”
The findings offer a new perspective on fermentation: not as a simple process in which bacteria merely do their job, but as a dynamic ecosystem in which microorganisms continuously respond to their environment and to one another. In the future, this knowledge may help researchers and food producers manage fermentation processes more effectively. This could lead to even safer products, more consistent quality, and potentially new flavours and textures.
PhD title: Competitiveness-enhancing factors in the fermented meat isolate Staphylococcus shinii IMDO-S216: a genomic and (meta)transcriptomic approach
Link to a recent publication: https://link.springer.com/article/10.1186/s12864-024-10490-0
More information:
Ana Sosa Fajardo: Ana.Sosa.Fajardo@vub.be: +32 470 86 43 00
Supervisor:
Prof. dr. ir. Frédéric Leroy: +32 477 53 15 81
Frans Steenhoudt
