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Diversity and evolutionary significance of feather-degrading bacteria in birds
Kyptová, Markéta ; Javůrková, Veronika (advisor) ; Reif, Jiří (referee)
Although to date this fact has been widely neglected, avian plumage is inhabited by a wide range of bacteria able to utilize keratin, the basic structural unit of feathers. If these keratinophilic, so called feather-degrading bacteria (hereafter FDB) get out of control, it can lead to significant changes in the plumage structural properties, resulting in impaired thermoregulation, flight performance, and expression of plumage ornaments. These may have significant consequences on reproductive success and overall fitness of individual. Based on these facts, it is hypothesized that PDB pose strong selective pressure lying behind the evolution of defense mechanisms such as size and chemical composition of uropygial gland, deposition of pigments into the feathers, or molting strategies that have been observed to eliminate the negative effect of FDB. The aims of this bachelor thesis are, on the basis of available literature, to summarize findings related to overall diversity and characteristics of plumage bacteria, to evaluate their effect on quality of plumage and individual fitness, and also to assess a role of microorganism in the evolution of different life- strategies in birds. Finally, this bachelor thesis points out the shortcomings of recent studies and proposes the concept for future research...
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An intensity of plumage bacterial load and resistence against bacteria-caused feather degradation in tropical birds of Afromontane areas of Cameroon
Kyptová, Markéta ; Javůrková, Veronika (advisor) ; Adamík, Peter (referee)
Microorganisms are considered to be a significant selective factor affecting bird's life strategies. The body cover, including feather, is occupied by a wide range of bacteria that are in their host in different interactions. Group of microorganisms degradate keratins of feather is still most studied and most species of birds have them in feather. This feather degrading bacteria can disrupt the wear and its function and thus cause great losses to its fitness. Therefore, it seems likely that these feathers degrading bacteria and microorganisms generally play a significant role in creating defence mechanisms against their negative effects. One of the most important defence mechanisms to protect feathers against the action of microorganisms is the deposition of melanin pigments. This diploma thesis deals with the analysis of the total bacterial load in feathers and its resistance against bacterial degradation in 47 species of birds trapped in afromontan areas of western Cameroon. The specific aim of the thesis was to determine differences in the total number of bacteria in plumage in species with different life strategies, especially feeding and reproductive strategies. At the same time, the phtilochronological analysis of the quality of the plumage was performed and in vitro experiments were tested...
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Diversity and evolutionary significance of feather-degrading bacteria in birds
Kyptová, Markéta ; Javůrková, Veronika (advisor) ; Reif, Jiří (referee)
Although to date this fact has been widely neglected, avian plumage is inhabited by a wide range of bacteria able to utilize keratin, the basic structural unit of feathers. If these keratinophilic, so called feather-degrading bacteria (hereafter FDB) get out of control, it can lead to significant changes in the plumage structural properties, resulting in impaired thermoregulation, flight performance, and expression of plumage ornaments. These may have significant consequences on reproductive success and overall fitness of individual. Based on these facts, it is hypothesized that PDB pose strong selective pressure lying behind the evolution of defense mechanisms such as size and chemical composition of uropygial gland, deposition of pigments into the feathers, or molting strategies that have been observed to eliminate the negative effect of FDB. The aims of this bachelor thesis are, on the basis of available literature, to summarize findings related to overall diversity and characteristics of plumage bacteria, to evaluate their effect on quality of plumage and individual fitness, and also to assess a role of microorganism in the evolution of different life- strategies in birds. Finally, this bachelor thesis points out the shortcomings of recent studies and proposes the concept for future research...
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Technological and senzorical quality of grain and baking products from spelt wheat
KYPTOVÁ, Markéta
This thesis deals with the baking quality of the spelt wheat grain (Triticum spelta L.) compared with common wheat (Triticum aestivum L.). Mixed flours were made of different share of spelt wheat and common wheat (in total 11 mixtures). The technological quality of these mixtures was analyzed, focusing on standard evaluation methods (protein content, characteristic of gluten or swellability of protein). The analysis was supplemented by complete rheological analysis made by MIXOLAB II. Bread was used as a model product. Subsequently, sensory evaluation of baked bread from the previously prepared mixtures was done. Part of the analysis was to estimate the economic basic bread recipe with different proportions of common wheat and spelt wheat. The results were statistically analyzed via STATISTICA 9.1 (StatSoft, Inc., USA). It was proved that the flour made of spelt can give cereal products with higher nutritional value. From a technological point of view, the results have shown that the spelt grain is much more suitable for baking. Its advantage is the higher protein content and higher resistence of kneading of the dough and starch gelatinization rate, which was statistically confirmed by Tukey HSD test. The other benefits of spelt grain is the higher nutritional value in comparsion to common wheat grain. The main disadvantage is the higher price of spelt. According to the results, the ideal utilization of spelt wheat based on sensory analysis and economic calculations seems to be the mixture of spelt wheat and bread wheat, which results in an undenieble decrease of the product cost, and hence effects the common customer choice and taste preferences.
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