The diploma thesis is focused on the occurrence and development of psychrotrophic microorganisms and their influence on meat and meat products, two experimental experiments were carried out. The first analysis concerns the determination of the microbial quality of pork and chicken meat packaged simply and in vacuum. The relationship between the development of microbiological contamination has been evaluated, depending on the storage life and the packaging method. Microbiological analysis samples were taken from the day of slaughter of slaughter animals, followed by the 1st, 3rd, 7th and 11th day of storage. This experiment was performed in two replicates. In the second analysis the development of CPM and psychrotrophic microorganisms in samples of heat treated meat products with the addition of whey and fiber, as well as during storage, was monitored. Laboratory analysis was performed immediately after manufacture and subsequently after 7, 10 and 14 days of storage without vacuum packing or packing in a protective atmosphere.

In this thesis, the knowledge about problematics of drinking water, with a focus on microbiology of drinking water, was summarized. The aim of this thesis was to analyse indicator microorganisms in ten samples of water. Four samples came from water wells, three samples were from water mains and there were three samples from bottled water. The microbiological analyze was conducted in two periods, namely in summer of 2018 and in winter of 2019. The results were evaluated in statistics and there was detected, if there is any difference in number of microorganisms in the summer and in the winter and also if there is a statistically significant difference between the given types of water. Most microorganisms were in raw water. Only one water of the wells water fulfilled microbiological requirements for drinking water. It was detected that there is no statistically significant difference in number of microorganisms in summer and in winter. In the total amount of microorganisms, there is a difference between water of wells and bottled water, and between water coming from water main and bottled water.

Findings that occurred during the practical part of the diploma thesis confirmed the working hypothesis that the application of biodegradable components to the soil has a positive influence on the activity of soil microorganisms. The greatest increase in microbial activity occurred with the use of manure, but in this application there was a greater degree of leaching of mineral nitrogen from the soil. Application of manure on arable land appears to be the best and most economical way to promote microbial acti-vity in soil.

The initial part summarizes current knowledge about impact of pesticides on microorganisms and their activity. It also deals with a description and effects of organic fertilization used in the experiment (compost and composted biochar). Based on the literature, we determined the hypothesis: Pesticides have negative effect on soil microbial activity, which was tested in the experimental part. In the experimental part, we carried out a pot experiment. We made two basic versions: a control soil without pesticides and a soil after the application of pesticides. We growed specimens of lettuce (Lactuca sativa) in pots. One version was without organic fertilization, next with amended compost and the last one with composted biochar. In total, we prepared six variants of pots, which were subjected to various measurements. We determined the production of aboveground and underground biomass and the root/shoot ratio. This measurement showed that the variants with pesticides are more suitable for plant growth, plants were bigger in both, aboveground and underground biomass, so they can probably uptake nutrients from soil degraded by pollutants, which can´t hold them back. We also monitored activity of microbial respiration by two methods: by measuring the absorbance of CO2 at soda lime and by the substrate induced respiration. The results showed a decrease in respiration of microorganisms in polluted soil in both of these measurements. Results of mineral nitrogen leaching suprisingly determined, that less nitrogen escaped in soil with pesticides in both forms, amonnia and nitrate, but its amount was generally very low. Cellulose test showed worse total breakdown of cellulose in contaminated variants. Phytotoxicity test revealed, that pesticides may have inhibiting effect on plant germination, but the active substances of pesticides can stimulate growth and development of plant sprouts.

Diploma thesis deals with stabile and labile organic carbon forms in soils. During 2009 - 2011 selected soil parameters in soil under different management were studying. Following parameters were chose - total organic carbon, labile carbon, and microbial carbon, content of humic substances, humic acids, fulvic acids, and basal soil respiration. Object of study was Luvic Chernozem (Unčovice), Haplic Cambisol (Vatín), and Haplic Luvisol (Lesonice). Soils were under classical tillage and minimum tillage system, and permanent grassland system. Obtained results showed that all studied soil types had satisfying content of total organic carbon and total nitrogen for soil microorganisms. The highest labile carbon content, microbial biomass and basal soil respiration was determined in permanent grassland soil.

This diploma thesis deals with the degradation of biologically degradable plastics. It focuses on the intensity of their degradation under the conditions of composting and on the influence of various factors on the colonization of biodegradable plastics by microorganisms. In the introduction of the theoretical part the key concepts of the field of biodegradable plastics are defined. The difference between plastics that are actually biodegradable and that are subject to only partial degradation is specified. Further the description of the process of biodegradation of polymers and the definition of biodegradability and compostability of polymer sis noted. At the end of theoretical part, the composting proces is described, with the enumeration of the phases and factors that influence the process. The practical part is devoted to the examination of the degradation of biologically degradable plastics in composting conditions both under a laboratory and under operating conditions. Laboratory experiment is complemented by the study of the influence of various factors on the process of biodegradation and on the intensity of colonization of biodegradable plastics by microorganisms.

This diploma thesis determines the level of microflora in meat from various suppliers. Literary research describes the methods used during the slaughtering process, up to meat cutting. It defines micro-organisms which cause both contamination and food-borne illness. It also describes possible ways of combating undesirable microorganisms as well as possible options to extend meat shelf-life. In the practical part, the following groups of microorganisms were measured by the means of a plate method: total number of microorganisms, coliform bacteria, yeasts and mildews, spore-forming bacteria, and psychotropic bacteria. A comparison among pork meat purchased in a store, in a butcher shop, from a home-grown breed and from a wild pig was provided. The lowest number of microorganisms was found in the meat coming from home-grown animals. All samples in the first day of measurement showed almost zero values for the determined groups of microorganisms, and their numbers were growing modestly in the following days. However, after a week of storing, the samples indicated no signs of spoilage, which should be reflected by the presence of microorganisms above 108 or 109 KTJ/cm2.

This diploma thesis describes important points in production of individual groups of meat products, which has significant effect on composition of microflora, especially the initial microflora of meat, heat treatment or fermentation. It defines saprophytic microflora and foodborne pathogens. It deals with microorganisms used in meat production and their improvements for the future. It suggests ways of combating undesirable microorganisms in meat products. Part of this work is experimental determination of the major groups of microorganisms in heat-treated meat products, specifically pates, during shelf life and after its expiration. The results shows that the company, that produces products examined in this thesis, has no problem with compliance to hygiene guidelines during manufacture, transportation and storage of pates.

Traditional medicine of indigenous cultures is based on the medicinal effects of local plants. Those people have been taught to use these plants throughout history and they employ them as their primary health care. This is supported by the fact that the natives do not have the financial resources to pay for medical care and at the same time it is also accompanied by poor availability of hospitals in areas where these cultures are located. This thesis covers laboratory verification of antimicrobial and antioxidant activity of Amazonian plants from south west Bolivia. This paper also summarizes the economic and political situation of the country together with the development of traditional medicine in the world and with the potential use of this medicine in pharmacy. Part of the work is devoted to the issue of ever-increasing antimicrobial resistance and the possible effects of free radicals in the human body. The experiment was performed by testing nine samples of imported dried plants in laboratory. To determine the antimicrobial properties a microdilution method was used and the antioxidant activity was verified with the ORAC method which is based on the elimination of free radicals. The microdilution method confirmed 80% of the MIC in the initial concentrations tested (1,024 mg/ml) in Satureja ovata plants against Staphylococcus aureus ATCC 33591 bacteria and Streptococcus pyogenes bacteria and in the plant Baccharis genistelloides against S. pyrogenes bacteria. The other samples have failed to provide the value of the minimum inhibitory concentrations. This can be attributed to several factors which are described in this thesis. In contrast the positive effect free radicals was confirmed in all samples. The highest efficacy showed Satureja ovata (1373,2 ug TE/mg extract). Writing this thesis was accompanied by a lack of information about the tested plants, both in terms of their botanical description and in terms of comparing the laboratory results obtained with the results of specialized studies. Therefore the results of the experiment were studied in comparison to traditional use of the tested plants that have been provided by Bolivian natives or their effects have been analyzed from the literature.

The thesis deals with microorganisms in meat products. Defines the microorganisms that cause food spoilage and foodborne disease-causing microorganisms. It describes the different types of meat products, their microflora and partially production. Proposes preventive measures undesirable microorganisms in the form of good hygiene practices and the implementation of HACCP system. Part of this work is the experimental determination of important groups of microor-ganisms in cooked meat products. The first part was compared to microbial contamina-tion meats products from three different manufacturers and in the second part was com-pared to microbial contamination products at the beginning and after expiration of the minimum durability. The results show that the microbiological contamination of meat products exceeded the limits set by the decree or CSN 56 9609, even after the end of their shelf-life.