Bacteria of the species Listeria innocua are non-pathogenic bacteria found in the environment and in food that have been used as model organisms in research because of their similarity to pathogenic bacteria of the species Listeria monocytogenes. Bacteria of the species L. innocua and L. monocytogenes form a biofilm that increases the survival of microorganisms in the food processing industry. Biofilm can be a source of contamination of work surfaces and hence transmission of pathogens to food. Due to the serious problems of biofilm formation within the food processing industry, the development of new alternative and cost-effective methods with rapid, accurate and specific analysis is urgently needed. In this master thesis, a new method was presented to quantify the presence, adhesion (incubation time 4, 8 and 24 hours) and film formation (incubation time 48 and 72 hours) of L. innocua bacteria with inserted luciferase gene and evaluation of quantification by measuring bioluminescence. The results were compared with those of previously established methods - the method for determining the number of adherent cells and biofilm cells, and the method for determining biomass after staining with the dye crystal violet. Quantification of presence, adhesion and film formation were also checked after treatment of cells with aqueous extracts from higher fungi. It was shown that the presented quantitative method by measuring bioluminescence is reproducible, sensitive, fast and specific and allows a more realistic assessment of presence, adhesion and film formation.
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