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Preparation of chitin film
Debnáriková, Michaela ; Abdelrahman, Rasha (referee) ; Abdellatif, Abdelmohsan (advisor)
Predložená bakalárska práca sa zaoberá extrakciou, čistením, rozpúšťaním a prípravou filmu na báze chitín/ polyvinylalkoholu (PVA). Čistý chitín bol úplne charakterizovaný rôznymi metódami, ako je potenciometrická titrácia, FT-IR, TGA, XRD, SEM a pevná NMR. Rozpustnosť a čistota extrahovaného chitínu sa skúmala a hodnotila meraním obsahu proteínov, pomocou reológie a skúmaním času potrebného na rozpustenie. Filmy chitín / PVA boli pripravené použitím rôzneho pomeru roztoku chitínu a PVA. Merané a vyhodnotené boli morfológia povrchu, reologické a mechanické vlastnosti filmu.
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The importance of bacteria for deadwood decomposition in forest ecosystems
Némethová, Ema ; Baldrian, Petr (advisor) ; Bárta, Jiří (referee)
Forest ecosystems represent a huge reservoir of carbon. The volume of deadwood in managed forests is in the tens of m3 h-1, while unmanaged forests have the volume of deadwood in hundreds of m3 ha- 1. Deadwood is a substrate with a high potential for decomposition. However, deadwood is a specific habitat that has a high C/N ratio and changes due to ongoing decomposition. The C/N ratio decreases with increasing decay time. In addition to the C/N ratio, the pH also changes during the wood pulping process, due to the decomposition of plant biomass by fungi. Moreover, deadwood has a high impermeability. The main decomposers of dead wood are fungi. In addition to them, bacteria, which are numerous in deadwood, also contribute to decomposition. Bacterial communities that decompose woody biomass are affected by these factors, and their distribution is also affected by dead tree species. The aim of this study was to describe how bacterial communities associated with deadwood change during decay. The most significant factor in the decomposition by bacterial communities is the time of decay. Bacteria found in short-decaying wood (less than 16 years old) are more diverse than those found in long-decaying wood. Methylotrophic bacteria and N-fixing bacteria are common in short-decaying wood as well. N-fixing...
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Preparation of chitin film
Debnáriková, Michaela ; Abdelrahman, Rasha (referee) ; Abdellatif, Abdelmohsan (advisor)
Predložená bakalárska práca sa zaoberá extrakciou, čistením, rozpúšťaním a prípravou filmu na báze chitín/ polyvinylalkoholu (PVA). Čistý chitín bol úplne charakterizovaný rôznymi metódami, ako je potenciometrická titrácia, FT-IR, TGA, XRD, SEM a pevná NMR. Rozpustnosť a čistota extrahovaného chitínu sa skúmala a hodnotila meraním obsahu proteínov, pomocou reológie a skúmaním času potrebného na rozpustenie. Filmy chitín / PVA boli pripravené použitím rôzneho pomeru roztoku chitínu a PVA. Merané a vyhodnotené boli morfológia povrchu, reologické a mechanické vlastnosti filmu.
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Peritrophic matrix of bloodsucking Dipteran insects.
Homola, Miroslav ; Sádlová, Jovana (advisor) ; Votýpka, Jan (referee)
The peritrophic matrix is an acellular envelope which surrounds the food bolus in the midgut of many animal species (especially in insects). It fulfils many functions in the midgut e. g.: protects the gut against an abrasion and against toxic substances, improves the digestion of food and protects the gut epithelium against pathogens. The last function might be the main reason of the occurrence of the peritrophic matrix in large amount of insect species. The peritrophic matrix is composed of chitin fibres and proteins. Chitin provides the peritrophic matrix strength and flexibility. Chitin fibres can be organised into three elementary structures: random, hexagonal and squared. The size of pores in peritrophic matrix depends on incorporated proteins - especially peritrophins. These pores determine the permeability of the peritrophic matrix for various penetrating molecules including digestive enzymes. This bachelor thesis is focused on Insecta sensu stricto (Hexapoda) and mainly on the order Diptera, especially bloodsucking species. Following chapters review recent information about the peritrophic matrix and its nomenclature, occurrence, assembling, composition and functions. Powered by TCPDF (www.tcpdf.org)
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