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Assessment of the environment hygiene level in selected food establishments and households
DROZDOVÁ, Aneta
An adequate level of hygiene of the food handling environment is one of the important factors that influence the maintenance of food quality and safety. The aim of this thesis was (i) to assess the level of hygiene in selected households (n=3) and food processing establishments (n=3) by microbiological analysis. The microbiological analysis included the determination of: total aerobic and psychrotrophic microorganisms, coliforms, as well as yeasts and moulds. In addition, (ii) to examine information regarding food handling practices through a questionnaire survey of food establishment employees (n=50) and the general public (n=259).
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Mikrobiální kontaminace masa používaného ke krmení psů a koček v rámci syrové diety
HOSNEDLOVÁ, Barbora
Raw feeding, also called BAFR diet, is the practice of feeding a diet consisting of raw meat, offal and side dishes. The goals of the thesis were (i) to utilize a question-naire survey among breeders practicing the BARF diet (307 responders) to obtain further information about their motivation for practicing this diet, type of meat used and its treatment, and (ii) to microbiologically analyze two kinds (chicken, beef) of raw meat during the three days of its storing. It has been found that the main reason for practicing the BARF diet is that it's more natural and healthier for the animals according to the owners. The responders prefer frozen meat (87%) that they store in the refrigerator prior to consumption and keep it there for up to 3 days. The most commonly used types of meat are beef and poultry (55%). More than a half (58%) of the responders use the same tools for both preparing the feed dose as well as for preparing the meals for their household. The microbiological analysis of the meat confirmed an increase in the total number of microorganism and the number of coli-form bacteria during the three days of storage in the refrigerator - in chicken meat this increase was from 6.3 KTJ/g, respectively 4.8 KTJ/g (1st day) to 8.3 KTJ/g, respectively 6.4 KTJ/g (last day), for beef from 6.5 KTJ/g, respectively 4.3 KTJ/g (1st day) to 8.3 KTJ/g, respectively 5.5 KTJ/g (last day). A significant increase in number of microorganisms, some of which may cause human diseases, occurs while the feed meat is being stored in a refrigerator for a usual amount of time. It is therefore necessary to appeal for more hygienic manipu-lation when practicing this type of diet, which is also related to raising the pet own-ers' awareness of this issue.
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Posouzení účinnosti sanitace chladicích zařízení v různých provozech
DROZDOVÁ, Aneta
The adequate level of hygiene of refrigeration equipment is one of important factors that affects the maintenance of quality and safety of stored food. The aim of this bachelor thesis was to assess the efficiency of sanitation of selected refrigeration equipment in the household (n=3) and in gastronomic establishments (n=3). Microbiological analysis enabled the determination: total number of mesophilic, coliform and psychrotrophic microorganisms, and also yeasts and fungi.
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The Influence of Microbial Degradation of Biochar in Soil on its Physico-chemical Properties
Kurková, Marie ; Weidlich, Tomáš (referee) ; Kalina, Michal (advisor)
This master‘s thesis studies the different factors that can affect biochar in soil and cause its degradation. These factors include irrigation, root exudates and the action of microorganisms. In the experimental part, the degradation of biochar in the soil environment was studied in two ways, firstly without the action of microorganisms, where the effect of irrigation was simulated by leaching biochar in ultrapure distilled water and model rainwater, and the effect of root exudates was simulated by extracting of biochar in citric acid as a model root exudate of maize sown. The extracted biochar solutions without prior cultivation in soil were characterized by pH, conductivity, UV-VIS analysis and elemental analysis. The biochar residues after extractions were characterized for morphology by SEM, structural differences by FTIR, and organic and mineral content by TGA analysis. The biochar samples after cultivation in soil were subjected to extractions under the same conditions and the same analyses were performed. The effect of cultivation in soil on biochar resulted in a change in elemental composition, a decrease in biochar alkalinity and changes in the ratio of organic matter and mineral fraction were observed. The decrease in pH and conductivity of biochar was mainly related to potassium leaching. The structural and morphological analysis indicated that there is no significant degradation of the structure of the biochar due to washing or cultivation in soil, but there is a partial fouling of the biochar pores by low molecular weight impurities from the soil. These results suggest a short-term action of biochar in soils as a source of nutrients (potassium, phosphorus) and, conversely, a long-term action as a soil conditioner.
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The influence of the dominant trees and grain substrate the composition of the microbial community studied by PLFA
Stachová, Sandra ; Frouz, Jan (advisor) ; Heděnec, Petr (referee)
The aim of the thesis was to analyze soil microbial communities of three ecologically different locations, about 25 years old, forestry reclaimed dumps in the Republic of Poland, namely dumps of brown coal mine Bełchatów and sand mines Piaseczno and Szczakowa. I evaluated the degree of dependence of structure and composition of these communities on various substrate grain sizes and the influence of the dominant tree species. These were stands of birch (Betula pendula), pine (Pinus silvestris), oak (Quercus robur) and alder (Alnus glutinosa). Analysis of soil microbial communities was made by evaluating specific phospholipid fatty acids (PLFA) of microorganisms. It is the most appropriate way to implement the relatively rapid analysis of large numbers of samples, since PLFA are easily extractable and act as biomarkers indicating the presence of a number of different microorganisms (fungi, G- and G + bacteria, Actinobacteria, etc.) and thus allowing a qualitative and quantitative assessment of whole microbial communities. PLFA analysis enables to detect a total concentration of PLFA only in living soil microbial biomass. I analyzed 66 soil samples, 33 from an Oe layer and 33 from an A layer, every in three replications, i.e. three replications were collected at each location below each tree...
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Role of microorganisms in the evolution of reproductive strategies in birds
Novotná, Lucie ; Javůrková, Veronika (advisor) ; Ferenc, Michal (referee)
Microorganisms are ubiquitous and can be found on the body of birds, in avian nests or may be carried into the nest along with nest-lining material. Microorganisms may therefore colonize eggshells of eggs in a clutch and subsequently penetrate into the egg contents. This so called trans-shell infection has been observed to affect hatching success, cause embryo mortality or subsequently influence hatchlings phenotype. Nevertheless, the probability of eggshell bacterial load or trans-shell infection depends on many factors, including environmental conditions, nest type, incubation pattern, and nest-lining material. Furthermore, some modifications of avian reproductive strategies may lead to reduction of negative effect of trans-shell infections, and significantly improve reproductive success. These mechanisms include incubation, mechanical and chemical barriers of egg, eggshell pigments or using of feathers and specific plants as nest lining material. Based on these findings, it can be concluded that the different reproductive strategies in birds should be a result of strong selective pressure caused by microorganisms. Although many recent studies have supported this assumption, research on this issue still suffers from many methodological shortcomings that must be eliminated in future studies.
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Temperature-dependent activity of egg-white antimicrobial proteins in precocial and altricial birds
Novotná, Lucie ; Javůrková, Veronika (advisor) ; Krist, Miloš (referee)
Microorganisms are considered to be crucial selective factor affecting reproductive success of birds. It is hypothesized that egg-white antimicrobial proteins and incubation behavior are the most important defense mechanisms that eliminates the risk of microbial trans-shell infection. The latest studies supposed that incubation temperatures may significantly affect the antimicrobial activity of egg white proteins. The concentration of egg white antimicrobial proteins as well as incubation patterns differ among altricial and precocial species of birds. However, experimental study testing the effect of incubation temperature on the antimicrobial potential of antimicrobial egg white proteins in altricial and precocial birds is missing. In this study we tested in manipulative experiment the effect of partial and full incubation, the concentration of lysozyme and ovotransferrin and their interactions on the antimicrobial activity of egg whites of two model species - Japanese quail (Coturnix japonica) and home pigeon (Columba livia). Antimicrobial protein activity was determined by the agar well diffusion method against two Gram-positive bacteria - Bacillus subtilis and Micrococcus luteus that have been documented as pathogenic egg-white invaders of several birds. Moreover, we analyzed the effect of...
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Raman spectrometry of carotenoids of selected microorganisms
Novotná, Julie ; Jehlička, Jan (advisor) ; Machovič, Vladimír (referee)
In this thesis Raman spectroscopy is evaluated as a tool of identification and discrimination of carotenoids from microbial biomass. Microorganisms, halophilic or nonhalophilic, belong to Cyanobacteria, Proteobacteria, Chlorophyta, Rhodophyta and to others. Biomass was cultiveted under laboratory conditions and yielded varied colours. Raman spectra were recorded succesfully from lyophilized biomass by excitation wavelenth 514.5 nm (dispersive Raman microspectrometr) and 1064 nm (FT Raman spectrometer). Results were compared with Raman spectroscopic data from pigment extracts. Spectra of carotenoids are characterized by the main Raman bands υ1, υ2 a υ3 due to C=C stretching, C-C stretching and C-CH3 deformation. HPLC/UV-VIS allows effective pigment separation from extracts and detection of separated pigments by UV-VIS analyzator. Assessment of Raman analysis and its potential to detect microbial carotenoids are discused. Sarcinaxantin is an unusual carotenoid identified together with more common β - carotene. Raman spectroscopic results obtained on carotenoids recorded from colonies which accumulated more than one carotenoid need to be interpreted carefully. Powered by TCPDF (www.tcpdf.org)
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