National Repository of Grey Literature 23 records found  beginprevious14 - 23  jump to record: Search took 0.00 seconds. 
Study of growth and optimization of selected metabolites production by Zymomonas mobilis
Lukačková, Adéla ; Vránová, Dana (referee) ; Babák, Libor (advisor)
In the diploma thesis are discussed the process of enzymatic hydrolysis of waste paper as a source for the production of bioethanol by bacteria Zymomonas mobilis. In the theoretical part summarize basic information about particular methods of hydrolysis, about paper used as a raw material for enzymatic hydrolysis, about possibilities of the fermentative production of bioethanol focusing on the method of simultaneous saccharification and fermentation comparison with enzymatic hydrolysis and fermentation. Suitable microorganisms for ethanolic fermentation and simultaneous saccharification and fermentation and their advantages and disadvantages, are further discussed in this part as well. The theoretical part ends with the suggestion of the technological process for production of bioetanol. It covers all necessary steps from the input of raw material to the separation of produced ethanol. In the experimental part various parameters of hydrolysis, fermentation and simultaneous saccharification and fermentation were optimized using enzymes from Novozymes® company and the Zymomonas mobilis CCM2770 and Zymomonas mobilis LMG457 bacterium. The conversion rate of paper cellulose to gluckose and production of ethanol were observed by HPLC/RI method. Type of buffer, quantity of cells, enzyme and substrate were optimized in order to maximize the efficiency of the process. All experiments were performed on paper containing high amount of cellulose and for comparison on standard medium which contains gluckose. The highest yields was achieved with the use of Novozymes® Cellulosic ethanol enzyme Kit. The strain Zymomonas mobilis LMG457 has demonstrated as a better producer.
The enzymatic hydrolysis of waste paper - a source of raw materials for production of liquid biofuels
Lepař, Petr ; Stloukal, Radek (referee) ; Gabriel, Petr (advisor)
In diploma thesis the process of enzymatic hydrolysis of waste paper as a source for the production of liquid biofuels is discused. It follows directly the homonymous diploma thesis from Ing. Brummer, and it is based on the findings, which were solved and decided in previous work. In the theoretical part there is a summarization of basic information on the enzymatic hydrolysis of waste paper and the associated influences of various factors of the rate and degree of hydrolysis. Higher attention is paid to a waste cardboard and its pretreatment methods due to the maximalization of the yield of hydrolysis. The next part summarizes options of the fermentative production of biofuels, focusing on the method of simultaneous saccharification and fermentation, where the further appropriate organism for ethanol fermentation is discussed. The last part is about the technological process from the raw material input to the separation of ethanol. In the experimental section the pre-treatment of waste paper in order to maximize the efficiency of hydrolysis was examined. The best results were achieved using a vibratory mill. In addition, various parameters for simultaneous saccharification and fermentation were optimized using enzymes from Novozymes® company and the yeast Saccharomyces cerevisiae. The conversion rate of waste paper cellulose to reducing sugars was observed by spectrophotometric method by Somogyi - Nelson and the amount of produced ethanol was quantified using HPLC / RI. As a part of this thesis some conditions (amount of enzyme, substrate, nutrients, yeasts, temperature, pH, type of buffer) were optimized to maximize the effectiveness of the overall process. All experiments were carried out on corrugated cardboard, which was chosen as the most promising material for hydrolysis that was among the waste paper pulp in diploma thesis by Ing. Brummer.
Enzymatic hydrolysis of waste paper pulp - source of raw material for production of liquid biofuels
Brummer, Vladimír ; Ing.Marián Illáš (referee) ; Gabriel, Petr (advisor)
This master’s thesis is aimed at process of enzymatic hydrolysis of lignocellulosic material – waste paper as a source of raw material for production of liquid biofuels. In the theoretical part of this work are summarized previously used methods of hydrolysis and lignocellulosic materials used for the process of hydrolysis as a source of fermentable sugars for fermentation technology. The different types of waste paper are evaluated from the composition and usability with consideration to the papermaking process in order to select the appropriate type of waste paper for the enzymatic hydrolysis process. In the next part of this work are suggested technological premises and procedures for the preparation of raw materials and the subsequent enzymatic hydrolysis of these pre–treated materials. In the experimental part were optimized parameters of enzymatic hydrolysis using the Novozymes company enzyme package. Enzymatic degradation of cellulose to reducing sugars was observed using Somogyi – Nelson method. For the verification of hydrolysis conditions were used model materials with high cellulose content – pulp and filter paper. Conditions, which seems to be the best after testing on the model materials, were verified on specific waste paper materials – offset cardboard, recycled paper, matte MYsol paper and for comparison again on model materials – pulp and filter paper. The highest yields was achieved with the use of cardboard, which was further tested using various combinations of pretreatment to material for purpose of increase the yields of hydrolysis.
Hydrolytic cleavage of coffee spent ground
Skřivanová, Veronika ; Hlaváček, Viliam (referee) ; Obruča, Stanislav (advisor)
The bachelor thesis deals with various types of hydrolysis of spent coffee ground for the following biotechnological applications such as the culture medium. The work included mechanical, acid, alkaline and enzymatic hydrolysis. The resulting hydrolysates were analyzed concerning the content of reducing carbohydrates, and potentially inhibitory substances polyphenolic nature. The results show that the best conditions for culturing yeast samples were prepared with a concentration of coffee 150 g/l hydrolysed combination of 2,5% mineral acid by heating at 121 °C for 15 minutes. Using ultrasonic homogenizer significantly increases the effect of hydrolysis. The enzymatic hydrolysis is best placed hydrolyzate prepared cellulase. The hydrolysed spent coffee grounds were used as the production medium for the production of ethanol by Saccharomyces cerevisiae. For samples was determined concentration change of glucose and ethanol by HPLC/RID. The highest concentration of biomass sample contained hydrolyzed cellulose on the other side, the highest yields of ethanol (20,07 g/l) were achieve using hydrolysate prepared by 2,5% hydrochloric acid.
Biotechnological production of polyhydroxyalkanoates using wastes of coffee production
Vašíčková, Monika ; Benešová, Pavla (referee) ; Obruča, Stanislav (advisor)
This bachelor thesis is focused on study of production of polyhydroxyalkanoates (PHA) by bacteria Burkholderia cepacia and Burkholderia sacchari. Production of PHA has been studied using spent coffee grounds hydrolysates which have been prepared by different aproaches. In the thesis is compared standard method of coffee ground hydrolysis by mineral acid followed by enzymatic hydrolysis. Hydrolysates which have been produced were analyzed in terms of concentration of saccharides and efficiency of hydrolysis. The best producer of PHA (based on results) was bacterium Burkholderia cepacia, in the medium which has been prepared by hydrolysis of spent coffee grounds extracted by 60% solution of ethanol. Biomass yield of this cultivation was 3,553 g/l with 32,472% PHA content. This PHA contained 6,09% 3-hydroxyvalerate. In the other experiment, we verified alternative hydrolysis of spent coffee grounds – by commercially available enzymes. We used cellulase, hemicellulase and the enzymatic cocktail which has been produced by mould. Hemicellulase was the most effective hydrolytic enzyme and its application resulted in production of the highest amount of biomass – 5,708 g/l. In this cultivation, only homopolymer PHB has been which is probably caused by the fact, that during the enzymatic hydrolysis levulinic acid or any other potential precursor of 3HV is formed.
Production of liquid biofuels by using enzymatic hydrolysis of waste paper
Roštek, Martin ; Jecha, David (referee) ; Brummer, Vladimír (advisor)
This bachelor thesis focuses on the retrieval summary of current knowledge about the process of enzymatic hydrolysis with utilization of waste paper as raw material, in order to convert it into liquid biofuels. The thesis summarizes the general knowledge of the lignocellulosic a raw materials and their resources, an overview of available hydrolysis methods for materials and fermentation technologies, and also summary of methods currently used to rise enzymatic hydrolysis process effectivity. The next section provides an overview of commercial plants which use enzymatic hydrolysis of lignocellulosic materials.
Use of wastes from winemaking in food and cosmetics applications
Výmolová, Markéta ; Němcová, Andrea (referee) ; Márová, Ivana (advisor)
The presented thesis deals with the various types of hydrolysis of waste from the production of wine, parings and bunch-stems for subsequent biotechnological use as enrichment of feeding mixtures and the production of bio-ethanol. A composite analysis was done at the start of the measurements for the determination of dry matter, extraction of oil from the parings and assessment of cellulose in the bunch-stems. As a part of this thesis a chemical and enzyme hydrolysis of waste materials have been performed. In hydrolysates the contents of reducing carbohydrates and antioxidants, polyphenols and flavonoids were analysed. The results showed that the samples with a concentration of 50 g/l of material hydrolysed in a water bath for 60 minutes were the best conditions for cultivating yeasts. Hydrolysed parings and bunch-stems were used as the production medium for the production of ethanol in Saccharomyces cerevisiae. A change of the concentration of carbohydrates and ethanol in the samples has been measured by HPLC. The sample hydrolysed enzymatically using cellulase exhibited the highest concentration of biomass (c = 2,140 g/l), the sample hydrolysed chemically in the water bath formed the highest content of ethanol (c = 9,880 g/l).
Enzymatic decomposition of a locked nucleoside phosphoramidate monitored by 31P NMR spectroscopy
Procházková, Eliška ; Hřebabecký, Hubert ; Nencka, Radim ; Dračínský, Martin
Phosphoramidate derivatives are often used as prodrugs of modified nucleosides. The crucial step for the biologically active compound release in cells is then enzymatic hydrolysis of the phosphoramidate derivative. The enzymatic decomposition of a nucleoside prodrug 1 was monitored using 31P NMR spectroscopy and the structure of the reaction products was determined by 1D and 2D (COSY, HSQC, HMBC) NMR experiments and compared with the products obtained with non-enzymatic hydrolysis of the prodrug.
Alcohol Yield of Oat, Barley and Wheat Hydrolysates
PIKL, Miroslav
Major part of ethanol production for industrial use in Czech Republic is made from cereals. Effect of acid, alkali and enzymatic hydrolysis after thermopressure preparation takes part in the paper. The most promising alternative is enzymatic hydrolysis. Especially efficiency of different hydrolytic enzymes towards different species of cereals takes the main part of the simulations. Local farm products, oats, barley and wheat were prepaired by steam explosion in different pressure. After hydrolysis were detected the GE and after fermentation was observed the production of alcohol.
LC-NMR metoda pro analýzu volných mastných kyselin v přírodních olejích
Sýkora, Jan ; Sovová, Helena ; Kurfürst, Milan ; Schraml, Jan
This contribution deals with LC-NMR method for analysis of free fatty acids in natural oils.

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