The aim of this study was to evaluate the combined effect of temperature (10, 20 and 37°C), pH (4, 5, 6, 7 and 8), and NaCl content (0, 1, 3, 4, 5 and 6% w/v) on the growth and putrescine and cadaverine production of Serratia marcescens CCM 303 under model conditions. The decarboxylase activity of S. marcescens was monitored in broth after cultivation. The cultivation medium was enriched with selected amino acids (ornithine, arginine and lysine; 0.2% w/v each) serving as precursors of biogenic amines. Levels of putrescine and cadaverine in broth were analysed by high-performance liquid chromatography after pre-column derivatisation with o-phthalaldehyde reagent. S. marcescens produced higher amounts of putrescine (up to 2096.8 mg L(-1)) compared to cadaverine content (up to 343.3 mg L(-1)) in all cultivation media. The highest putrescine and cadaverine concentrations were reached during cultivation at 10-20°C, pH 5-7 and NaCl content 1-3% w/v. On the other hand, the highest BAs production of individual cell (recalculated based on a cell; so called "yield factor") was observed at 10°C, pH 4 and salt concentration 3-5% w/v as a response to environmental stress.

The aim of this study was to characterise the contaminating microorganisms during individual stages of manufacture of quark-type cheese and also describe their capability of biogenic amine production. We isolated and identified 118 contaminating microorganisms for which the production of biogenic amines has been established. Over half of the isolates were capable of significantly producing at least one biogenic amine and, in some cases, multiple amines (content values for a particular biogenic amine exceeding 200 mg/L of broth). The strongest production ability of the isolated microorganisms was for putrescine and tyramine.

This study reports the development of selected indicators affecting changes in food quality and safety of selected long-life canned (Szeged goulash, canned chicken meat, pork pâté, canned tuna fish) and dehydrated (instant goulash soup) food during a two-year storage experiment at four different temperatures. The storage temperatures were selected to represent Arctic (−18 °C), temperate (5 °C), subtropical (25 °C) and tropical (40 °C) climatic zones where such food is likely to be stored during, for example, humanitarian and military missions. Microorganism amounts below the detection limit (p < 0.05), regardless of the storage temperature (p ≥ 0.05), were monitored in canned samples. The contents of dry matter, fat and proteins did not change during storage, regardless of the storage temperature (p ≥ 0.05). During the 24-month storage, all food showed an increase in the level of ammonia (p < 0.05) and the TBARS-value (p < 0.05), whereas the rate of increase in both parameters was significantly higher at higher storage temperatures (p < 0.05). The losses of individual amino acids during storage ranged from 5% rel. calculated on the amino acid contents in Month “0” up to 15% rel. (p < 0.05). With storage temperatures above the freezing point, the hardness values decreased with the increase in the storage temperature (p < 0.05) and prolongation of the storage period (p < 0.05). Moreover, with temperatures of −18 °C, the development of hardness, measured as the “decrease rate”, was significantly higher compared to the absolute values.

The aim of this study was the isolation and characterization of microorganisms able to degrade biogenic amines and their identification. Individual microorganisms were obtained by isolation from commercially available foodstuffs and food produced in the technological laboratories of Faculty of Technology, Tomas Bata University in Zlín and subsequently identified by MALDI-TOF MS. The results of MALDI-TOF MS identification were verified by 16S rRNA sequenation. In this work was studied the ability of 5 bacterial strains positive to biogenic amines degradation isolated from dairy products to decrease biogenic amines content in vitro and quantified reduction in the concentration of biogenic amines tryptamine, β-phenylethylamine, putrescine, cadaverine, histamine and tyramine. The level of degradation (decrease of biogenic amines) was determined on the base of the ability to grow in media with biogenic amines as the sole source carbon and nitrogen. The isolated strains with the ability of degradation of one or more biogenic amines were cultured in medium supplemented with relevant biogenic amines, the media derivatized with dansyl chloride and these amines separated by HPLC at a wavelength of 254 nm. From five tested strains identified as Bacillus subtilis, Bacillus pumilus, Enterobacter cloacae, Rhizobium radiobacter and Acinetobacter pitii, isolated from gouda type cheese, the greatest ability of degradation was observed in Bacillus subtilis, which was capable to degrade almost all amount of histamine, cadaverine and putrescine. Other four strains showed a lower rate of degradation than Bacillus subtilis, but the ability to degrade biogenic amines with these microorganisms was still significant.

The aim of the study was the monitoring of six biogenic amines (histamine, tyramine, phenylethylamine, tryptamine, putrescine, and cadaverine) and two polyamines (spermidine and spermine) in 30 samples of dairy products purchased in the Czech Republic, namely in 15 samples of mould-ripened cheeses and in 15 samples of smear-ripened cheeses. A further goal was the microbiological analysis of the individual samples of cheeses (total count of microorganisms, number of enterobacteria, enterococci, lactic acid bacteria, yeasts and moulds). The monitored biogenic amines were analyzed by a high performance liquid chromatography equipped with a UV/VIS DAD detector. The amount of enterobacteria in fresh cheese exceeded 10 5 CFU.g -1 . In smear-ripened cheese flavourless (Romadur type), the amount was >10 3 CFU.g -1 and 10 4 -10 5 CFU.g -1 in smear-ripened cheese with flavour. Biogenic amines were observed in two groups of blue cheeses (white veined cheese and blue veined cheese) and smear-ripened cheeses. In both groups, there is a possibility of the presence of biogenic amines because the number of microorganisms and concentration of free amino acids increase during ripening. In ten samples of soft smear-ripening acid cheese and in smear-ripened cheese, the total content of biogenic amines were 22-1000 mg.kg -1 and in 5 samples of these cheeses, it was in range 1000-6000 mg.kg -1 . The total amount of biogenic amines in the blue cheeses were in range 40-600 mg.kg -1. The presense of the tyramine was observed in the all analysed cheeses. The tyramine producing strains generated more than 900 mg.kg -1 of this biogenic amine. The production of tryptamine in the analysed cheeses was not proved by this study. The results of this study show that biogenic amines and polyamines are common in cheese. However, in some cases, they can pose a significant health danger for consumers. Any legislative control authority does not monitor them, as they are secondary metabolites even though they are potential health risks.