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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Vliv symbiotické fixace vzdušného dusíku na tvorbu výnosotvorných prvků u sóje

Jaroš, Antonín January 1993 (has links)
No description available.
112

Vliv rostlin na strukturu, funkci a diverzitu společenstev bakterií / Effects of plants on the structure, function and diversity of bacterial communities

Havlíčková, Petra January 2018 (has links)
Vegetation is known to influence the composition of microbial communities. Bacteria can act as roots symbionts or be involved in the decomposition of plant biomass. They can be influenced by soil chemistry but also by plant exudates. Some plants produce targeted exudates to attract specific bacteria to their roots. Bacteria associate with plants frequently but the effect of plant diversity on bacterial communities on their roots and in the surrounding soil remains unclear. The aim of this work was to describe the relationship between the diversity and community composition of bacteria and the diversity of vegetation in forest and grassland ecosystems. The study areas were selected to represent a gradient of vegetation in Bohemian Forest NP and in White Carpathian flowery grasslands. I hypothesized that the diversity and evenness of bacterial community increase with increasing plant diversity. The composition of bacterial community was characterized by 16S rRNA sequencing. The composition of vegetation was determined by phytocenological relevées and by molecular markers trnL. In grassland ecosystem, there was a positive relationship between plant and bacterial diversity only in shoots. The space and vegetation were identified as an important drivers of bacterial community composition in shoots. The...
113

Komplexní charakterizace subgingiválního plaku - využití moderních sekvenačních metod v diagnostice a sledování léčby onemocnění parodontu. / Complex characterization of subgingival plaque - use of modern sequencing methods in diagnostics and monitoring of treatment of periodontal diseases

Těšínská, Barbora January 2018 (has links)
Periodontitis is a multifactorial inflammatory disease which can result in a complete loss of teeth. Its main cause is the accumulation of bacteria from the dental plaque followed by massive reaction of the host immune system. It was proved that the composition of oral microbiome (OM) differs in periodontally healthy individuals and patients with periodontitis. This work aims to solve specific parts of the long-term project concerning the taxonomic composition of the OM of periodontally healthy individuals and patients with chronic and aggressive form of the disease. The OM was characterized based on 16s rDNA sequencing. It is evident from the results that the shift in the OM composition occurs prior the development of clincal signs of the disease and that the precise dental care can significantly postpone or even avoid the onset of the disease. When comparing the OM composition in individuals with chronic and aggressive periodontitis, no remarkable differences were detected to explain the faster progress of the aggressive form of the disease. This work also aimed to compare the results obtained by 454 pyrosequencing and Illumina. Both sequencing methods were found to provide statistically comparable results. Illumina MiSeq thus can be employed to build on the former results of the long-term study...
114

Prokysávací schopnosti mlékárenské suroviny / Fermentation capability of bulk milk under usual conditions

BOUŠKOVÁ, Lucie January 2012 (has links)
The evaluation of changes during fermentation of heat-modified milk in connection with different fermentation temperatures was main goal of this thesis. Titrable acidity, active acidity and growth dynamics of bacteria strains - Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus were observed during fermentation process.
115

Molekulárně biologická charakterizace vybraných producentů PHA / Molecular characterization of selected PHA producers

Kubáčková, Eliška January 2020 (has links)
This diploma thesis focuses on the molecular characterization of selected PHA producers. Within this work, the PHA producing thermophilic isolates originating from the samples of activated sludge and compost were identified and characterized using molecular biological methods. By sequencing the 16S rRNA gene, the thermophilic isolates were identified and taxonomically classified into the Firmicutes bacterial phylum. In these bacterial isolates, the ability to produce PHA at the genotype level was determined by conventional PCR detection of the phaC gene encoding PHA synthase, which is a key enzyme in PHA biosynthesis. Class I, II and IV PHA synthases were detected in most of the isolated bacteria, wherein class I and II PHA synthases are not characteristic for these bacterial genera. The largest proportion of isolates was identified for the species of thermophilic bacterium Aneurinibacillus thermoaerophilus, in which class IV PHA synthase was detected. In the second part of the diploma thesis, the RT-qPCR method was implemented to study the expression of selected genes of the bacterium Cupriavidus necator H16 involved in PHA metabolism. As part of the implementation of this method, PCR-based detection of selected genes was optimized and quantification of genes using real-time PCR was performed. The tested method included steps of RNA isolation, cDNA synthesis and quantification of gene segments for which the critical points of the method were determined based on the obtained data.
116

Tvorba biogenních aminů v dvouplísňovém sýru / Production of biogenic amines in double moulded cheese

Šuláková, Miroslava January 2009 (has links)
For production of double moulded chesses are used lactic acid bacteria, which can be present in a form of non-starter lactic acid bacteria or as starter or adjunct culture. Genera Lactobacillus spp. and Enterococcus spp. are prevalent microorganisms present in these cultures. Of course, these microorganisms are for us interesting because of their possibility of coagulation, proteolytic possibility, probiotic function and antibiotic resistance, but especially because of their decarboxylation abilities. Bacteria contain decarboxylation enzymes, which are able to decarboxylized free amino acid, which rising at proteolysis during process of manufacturing and cheese ripening. Biogenic amines are the result of proteolytic activity. Biogenic amines occur practically in all foodstuffs as a common product of metabolic processes. BA are mainly presented in fermented food (cheeses), where rice just microbial action. Typical representatives of biogenic amines, which occurs in double moulded cheeses (Sedlčanský Vltavín, Bresse bleu) and in blue cheeses (Bleu des Causses, Bleu d'Auvergne) are cadaverine, putrescine, tyramine a 2 fenylethylamine and in much smaller amount histamine, spermidine and spermine too. On assessment concentration of BA is used high pressure liquid chromatography with reverse phase (RP HPLC) with utilizing simple direct derivatization with dansyl chloride and detection by UV VIS detector.
117

Molekulární identifikace vybraných druhů bakterií mléčného kvašení a bifidobakterií v doplňcích stravy / Molecular identification of selected species of lactic acid bacteria and bifidobacteria in food additives

Riegelová, Kristýna January 2011 (has links)
Probiotic lactic acid bacteria and bifidobacteria are natural part of microflora of gastrointestinal tract. In the present, day they are grossly exploited in food processing industry. The aim of the work was molecular identification of bacteria of genus Lactobacillus and Bifidobacterium in complex matrices of two food additives. Total DNA was isolated from crude cell lysates by magnetic particles P(HEMA-co-GMA). Isolated DNA was amplified in genus-specific and species-specific PCRs. Amplicons were detected by agarose gel electrophoresis. Results were compared with declared specification given by producers in three different batches.
118

Identifikace vybraných druhů bakterií mléčného kvašení v mléčných výrobcích / Identification of selected species of lactic acid bacteria in dairy products

Vystavělová, Růžena January 2012 (has links)
Lactic acid bacteria are natural part of the human gastrointestinal tract. They are often used in food supplements and for the production of fermented dairy products. This thesis focuses on the identification of selected species of lactic acid bacteria and bifidobacteria in cheese and dairy products. Bacterial DNA was isolated by magnetic particles P(HEMA-co-GMA) from crude cell lysates from 9 products. Isolated DNA was amplified in genus-specific and species-specific polymerase chain reactions (PCR). The obtained amplicons were detected by agarose gel electrophoresis. The results of PCR were compared with those provided by the manufacturers and there has been declared a match.
119

Porovnání mikrobiální metabolické produkce na odpadní a sušené syrovátce / Comparison of microbial metabolic production from waste and powder whey

Elefantová, Petra January 2014 (has links)
The master’s thesis discusses the comparison of microbial metabolic production from waste and powder whey. Whey is obtained as a by-product of cheese production. Lactose (preferably whey) using lactic acid bacteria (eg. Lactobacillus) under suitable temperature conditions is converted to lactic acid. Effect of temperature, effect of salts and effect of yeast extract on lactic acid production by L. casei were investigated. HPLC metod was determined lactid acid. In the practical part were used bacteria of the genus Lactobacillus. It was found that for dried and waste whey is the optimal temperature of 35 °C. At this temperature is the greatest gain of lactic acid. The highest concentration of lactic acid was obtained by using 20 g of yeast extract for dried whey and for waste whey were used 24 g of yeast extract. When monitoring the effect of salt concentration on the production of lactic acid, it was found that using only MnSO4·H2O gain most of lactic acid.
120

Identifikace a charakterizace vybraných vlastností některých kmenů bakterií mléčného kvašení / Identification and characterisation of selected properties of some strains of lactic acid bacteria

Sásková, Denisa January 2015 (has links)
Nanotechnology is currently one of the fastest growing scientific disciplines. An interesting area of research is the biosynthesis of metal nanoparticles using microorganisms including lactic acid bacteria. In the first part this diploma thesis focuses on verification of identity of bacterial species Lactobacillus casei and Lactobacillus paracasei by genus- and species-specific PCR. In the next part of experimental work the capability of six Lactobacillus strains to produce silver nanoparticles is tested. Synthesis of nanoparticles was confirmed for all the strains depending on the amount of added AgNO3 and on time of cultivation. Differences between the strains were detected.

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