National Repository of Grey Literature 9 records found  Search took 0.01 seconds. 
Cellulolytic fungi and their diversity on plant litter
Gálová, Diana ; Baldrian, Petr (advisor) ; Kolařík, Miroslav (referee)
Litter decomposition requires the presence of corresponding degradative enzymes, produced mainly by fungi. Forest soils show considerable spatial heterogeneity of distribution of these enzymes at diferent scales. Moreover, enzyme pruduction varies during the year, usually accompanied by the change in fungal community composition. In this work I examined if this spatial heterogeneity can be seen even at a scale of an individual leaf and whether the fungal community differs among enzyme activity hotspots and inactive parts of the leaves. Another goal was isolation of celulytic fungi from cellulose litterbags incubated on forest floor using particle filtration and dilution-to-extinction method. In a broadleaved forest dominated by oak leaves at different stages of decay were collected: senescent leaves on twigs, and leaves after 2, 10 and 22 months of decomposition. Ten leaves per season were taken for analysis of cellobiohydrolase activity over the leaf surface. Leaves were attachmed onto melted agarose plate and leaf surface was covered with low melting point agarose containing fluorescently labelled substrate. For each leaf a map of enzyme activity was created and area with the high and low enzyme activity was identified. From both sites a square of approx. 1 cm2 was cut out, DNA was extracted and fungal...
Fungi associated with decomposing wood in temperate forests
Štercová, Lucie ; Baldrian, Petr (advisor) ; Zikánová, Blanka (referee)
Wood decaying fungi are an essential part of all forest ecosystems. On their functioning depends a number of other organisms which use substances produced during decay of wood. Enzymes that degrade wood represent indispensable tool for fungi in converting structural compounds of wood to water and carbon dioxide. That makes them an essential part of the carbon cycle in nature. The dynamic of fungal communities on decaying wood is determined by a range of abiotic and biotic factors. The variability of microclimatic conditions, differences in the wood humidity and a gaseous mode are identifying stress factors which define the presence of species adapted to those conditions. An important factor, with which we can partially predict community composition, is the degree of decomposition of wood and the history of a species on the substrate. Another indicator, which may partly explain the composition of the community is a way of dying of a tree and a type of decaying substrate. Often, the development of a community follows from the primary colonizers, with high tolerance to unfavorable conditions, through the secondary colonizers, which have the ability to obtain the substrate over primary colonizers, but require more stable microclimatic conditions, to late colonizers, who are adapted to stress factors as...
Ověření vlivu rozpustných fenolických látek na aktivitu extracelulárních enzymů v rašeliništích
KOVÁŘOVÁ, Lucie
The aim of the study was to verify the influence of the soluble phenolic compounds on the activity of extracellular enzymes. We tested the effect of aerobic and anaerobic conditions and addition of soluble phenolic compounds on potential activity of extracellular enzymes in two laboratory experiments. The results showed, that potential activities of oxidative extracellular enzymes such as phenol oxidase and peroxidase did not decline in anaerobic incubations, and have no oxygen requirement. Potential activities of hydrolytic enzymes was not inhibited by phenolic compounds and are oxygen related or have no oxygen relationship. No negative relationship between hydrolytic enzymes and phenolic compounds was observed. In summary, our results do not support the ''enzymatic latch'' hypothesis.
Fungi associated with decomposing wood in temperate forests
Štercová, Lucie ; Baldrian, Petr (advisor) ; Zikánová, Blanka (referee)
Wood decaying fungi are an essential part of all forest ecosystems. On their functioning depends a number of other organisms which use substances produced during decay of wood. Enzymes that degrade wood represent indispensable tool for fungi in converting structural compounds of wood to water and carbon dioxide. That makes them an essential part of the carbon cycle in nature. The dynamic of fungal communities on decaying wood is determined by a range of abiotic and biotic factors. The variability of microclimatic conditions, differences in the wood humidity and a gaseous mode are identifying stress factors which define the presence of species adapted to those conditions. An important factor, with which we can partially predict community composition, is the degree of decomposition of wood and the history of a species on the substrate. Another indicator, which may partly explain the composition of the community is a way of dying of a tree and a type of decaying substrate. Often, the development of a community follows from the primary colonizers, with high tolerance to unfavorable conditions, through the secondary colonizers, which have the ability to obtain the substrate over primary colonizers, but require more stable microclimatic conditions, to late colonizers, who are adapted to stress factors as...
Cellulolytic fungi and their diversity on plant litter
Gálová, Diana ; Baldrian, Petr (advisor) ; Kolařík, Miroslav (referee)
Litter decomposition requires the presence of corresponding degradative enzymes, produced mainly by fungi. Forest soils show considerable spatial heterogeneity of distribution of these enzymes at diferent scales. Moreover, enzyme pruduction varies during the year, usually accompanied by the change in fungal community composition. In this work I examined if this spatial heterogeneity can be seen even at a scale of an individual leaf and whether the fungal community differs among enzyme activity hotspots and inactive parts of the leaves. Another goal was isolation of celulytic fungi from cellulose litterbags incubated on forest floor using particle filtration and dilution-to-extinction method. In a broadleaved forest dominated by oak leaves at different stages of decay were collected: senescent leaves on twigs, and leaves after 2, 10 and 22 months of decomposition. Ten leaves per season were taken for analysis of cellobiohydrolase activity over the leaf surface. Leaves were attachmed onto melted agarose plate and leaf surface was covered with low melting point agarose containing fluorescently labelled substrate. For each leaf a map of enzyme activity was created and area with the high and low enzyme activity was identified. From both sites a square of approx. 1 cm2 was cut out, DNA was extracted and fungal...
Ecological roles of bacteria associated with plant litter
Tláskal, Vojtěch ; Baldrian, Petr (advisor) ; Seydlová, Gabriela (referee)
Leaf litter in temperate forests represents an important input of carbon into the soil. Main players in the decomposition of leaf litter are fungi and bacteria. While the role of fungi in litter decomposition was repeatedly addressed, there are just a few field studies where litter-associated bacteria were also considered. The aim of this work was to summarize available literature studying the structure and function of bacterial community during litter degradation. The nature of different possible substrates is discussed. Genetic approach is briefly outlined. Factors such as diversity, spatially distribution and abiotic factors that can influence community are also considered. It can be supposed that community composition changes with the change of litter chemistry and nutrient availability. The development of bacterial community might be driven by the decreasing availability of nutrients in litter. Labile compounds are utilised at the beginning of decomposition, while recalcitrant substrates are utilised later by specialist taxa. Members of the phyla Actinobacteria, Acidobacteria, Bacteroidetes and Proteobacteria seem to be dominant during decomposition. Different types of relationships between fungi and bacteria also most likely influence the composition of community. This review shows that the bacterial...
Enzyme activity and molecular characterization of fungi in decaying wood
KONAROVSKÁ, Kristýna
Decomposing wood is necessary part of forest ecosystem. Wood is robust and hardly decomposable material. Some fungi can use enzymes to degrade lingocellulose. This bachelor thesis is concerned with these fungi and enzymes. Goal of this work was to describe factors affecting composition of fungal community in deadwood. Two different kinds of trees - beech and fir had been sampled from trunks and branches and ergosterol content, fungal biomass, activity of extracellular enzymes and fungal community composition were determined. Main watched property has been different source of samples coming from tree trunks (T) or branches (B) and from Silver fir (FWD) or European beech (CWD) thus forming 4 categories FWD-T, FWD-B, CWD-T and CWD-B. Analysis confirmed higher potential activity of enzymes and higher pH in samples taken from branches specifically endocellulose, exocellulose, endoxylanase, N-acetylglukosaminidase a -glukosidase. Ergosterol marker confirmed higher biomass content in branches. Ascomycet or Basidiomycet fungi content was not dependent on type of wood or its size. Enzyme activity and fungi biomass with lower pH confirms higher fungi enzymes content in branches in comparison to trunks. Presence of fungi influences substrate thanks to active metabolism. Higher biomass values were linked to faster branches colonization and their decomposition.
Enzymatic hydrolysis of wastes associated with coffee production
Kovářová, Markéta ; Skoumalová, Petra (referee) ; Obruča, Stanislav (advisor)
This bachelor thesis is focused on study of potential production of extracellular hydrolytic enzymes by microorganisms – bacterium and moulds, which have been cultivated on spent coffee grounds. The theoretical part deals with characterization of coffee and utilization of coffee by-products. There are also subscribed microorganisms and enzymes which have been noticed. In experimental part coffee ground was used as the sole substrate for production of extracellular hydrolytic enzymes. Productions of protease, cellulase, mannase and lipase enzymes were observed. None-identified isolate of mould spontaneously contaminating spent coffee grounds was identified as the best producer of these enzymes. Subsequently the conditions of cultivation such as water content and shaking vs. static cultivation of this moulds were optimized. Further, we performed partial purification and pre-concentration of the enzyme cocktail by ultrafiltration, ultradialysis and PAGE-SDS characterization of extracellular enzymes was performed as well.
Activity of soil enzymes in the Norway spruce forests attacked by bark beetle
ŠLAJSOVÁ, Petra
Activity of enzymes was investigated in the soils of Norway spruce forests in the Bohemian Forest. The aim of the study was the determintation of the impact of temperature and plants dominant in understorey on the activity of extracellular enzymes in the soils in the watershed of Plešné and Čertovo Lake. The measurement of enzymes activities was conducted using the fluorometric method with model substrates.