# The Role of Microorganisms and Their Antibacterial Compounds in Food Biopreservation
## 6 New Technologies of Food Bioconversion as an Alternative to Artificial Preservation  
Generally, biopreservation is based on two principles, namely direct competition with undesirable microorganisms and the production of antimicrobial substances [108]. Meat and meat products are prone to spoilage and contamination by pathogenic microorganisms, and therefore require preservation. For this purpose, physicochemical treatments are widely used. Selected microorganisms, including probiotics, and natural antimicrobial agents inhibit spoilage and can also be effectively applied in meat and fish products as additional \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Food Product** & **Strain of Yeast** & **Action Mechanism** & **References** \\ \hline Cheese & _M. pulcherrina_ LMA 2038 & Antifungal and antibacterial inhibitions & [96] \\ \hline Coffee & _S.cerevisiae_ CCMA 1302 & Formation of biofilm, volatile organic compounds & [97] \\ \hline Apple juice & _R. mucilaginous_ & Competition for nutrients, degradation of the mycotoxin & [98] \\ \hline Wine & _M. pulcherrina_ & Secretion of lytic enzymes & [99] \\ \hline Fermented cured meat & _Meyerozyma guilliermondii_ & Degradation N-nitrosamine precursors; offer solution to problems with the high risk of generating nitrosamines such as N-nitrosodiethylamine (NDEA) by processing fermented meat products with nitrites as precursors. & [100] \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Usage of yeast in food biopreservation—selected examples. or alternative preservatives. Bacteriocins, especially nisin and pediocin, successfully inhibit the growth of _Listeria monocytogenes_ and have activity against _Salmonella_ spp., _Staphylocus aures_, and _E. coli_ in different meat and meat products [109; 110]. In dairy products such as milk, yoghurt, and cheeses, bioconservation was effective. The number of reports confirmed that LAB as a starter or adjunct culture, as well as bacteriocins (nisin, pediocin, lactisin, reuterin, enterocin) are successful in controlling pathogens occurring in dairy products (_Listeria monocytogenes_ and _Staphylococcus aureus_). In dairy products, bacteriocins alone do not ensure effective antimicrobial protection due to proteolytic degradation, poor solubility, and uneven distribution. Therefore, LAB strains producing bacteriocins are preferred because of safety, shelf-life lengthening, and sensory quality [70]. The shelf life of fresh-cut fruits and vegetables can also be improved using biocontrol agents, such as LAB, and their metabolites applied after inoculation or in edible coatings. These bacteria can reduce the contamination of fresh fruits and vegetables to pathogens [111]. There are many advantages of food biopreservation. The use of natural microbial preservation can be considered as an alternative or can supplement the physicochemical preservative methods (Table 4). The combination of bacteriocins with chemical preservatives offers potential antimicrobial synergistic results. Organic acids and NaCl treatment enhance the antimicrobial activity of most bacteriocins [112]. The antimicrobial synergistic effect of bacteriocins was shown also in a modified atmosphere (CO\({}_{2}\) and N\({}_{2}\)) [113]. The market is growing not only for natural preservatives but also for environmentally friendly and biodegradable packaging materials [114]. A common method of applying natural antimicrobial agents to food to extend shelf life is their direct addition and use in an active packaging system [114]. Active packaging is packaging in which additional ingredients have been placed inside the packaging and/or on the packaging in order to increase the efficiency of the packaging system. The task of active packaging is to extend the shelf life of food by actively influencing the packaging and/or packaging components on the packaged product or the environment inside the packaging [115]. The development and application of active packages for foods is a growing research area.