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The thesis deals with microbiology of dairy products made from goat's milk. The theoretical part deals with goat's milk, dairy products, and last but not least technologically and hygienically relevant microorganisms, located in products made from goat milk. This section also included measures as from unwanted and dangerous microorganisms defend. The practical part includes microbiological determination in 6 goat cheese samples and 5 goat products that were purchased directly on goat farms and in specialized stores. Microbiological analysis identified the following groups of microorganisms: the total number of microorganisms, lactic acid bacteria, yeasts and molds, enterococci and coliforms. The results were evaluated and compared with current legislation

The aim of the dissertation thesis, The Isolation of Microorganisms Producing Biogenic Amines from Milks and Dairy Products, was to isolate pure bacterial cultures of the genus Enterococcus and coliform bacteria from milks and cheeses and to test them for ability to produce biogenic amines. Isolated strains were identified and decarboxylase activity was tested on several amino-acids (lysine, histidine, tyrosine, tryptamine, ornithine, phenylalanine and arginine) at four different temperatures. At the end of the experiment, PCR was processed for the presence of tyrosine decarboxylase gene in enterococci strains. Identification showed higher variability of microorganisms isolated from cheeses rather than from milks. Decarboxylation activity test has revealed ability of genus Enterococcus to decarboxylate tyrosin and arginine. Coliform bacteria were found to be possibly able to decarboxylate arginine, tyrosin, ornithine, lysine and histidine. The subsequent PCR reaction confirmed most of the enterococci isolates to be producers of tyramine.

This masters thesis deals of microbial contamination of chicken eggs in storage. Test samples were tracked for the following microbial indicators: Total Viable Count (TVC), bacteria of the Enterobacteriaceae family, bacteria of the Enterococcus genus, psychrotrophic microorganisms, yeasts and molds. Microbial analysis was made for eggs acquired from market chains, originating from three different farming environments: enriched cages, cage-free and free range. Samples were stored in three different temperature environments: refrigerated at 5 °C for the whole storage period, stored in a thermostated box at 28 °C for the whole storage period and alternating between 5 °C and 28 °C temperature environments with one week storage periods each. The analysis of acquired test samples shows that TVC did not change significantly between different farming environments and storage temperature environments. Cage-free eggs show increasing TVC in long time storage (21 days). Cage-free and free range eggs also show higher count for Enterobacteriaceae. Enterobacteriaceae counts show significant differences between samples stored at constant 28 °C and alternating temperatures. Lowest microorganism count for bacteria of the Enterobacteriaceae family was observed at alternating temperatures. Long time storage resulted in elevated Enterobacteriaceae count in cage-free eggs. Presence of Enterococcus, psychotrophic microorganism and molds was detected in a low number of samples.

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