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Remediation Potential of Humic Acids
Uhrová, Anna ; Lehocký,, Marián (oponent) ; Pospíšilová,, Lubica (oponent) ; Kučerík, Jiří (vedoucí práce)
In this work, we tested the modified lignite humic acids for their remediation capability of agricultural soils. Prior to the extraction of humic acids, the parental raw lignite was modified by ten organic acids. The pre-treatment was aimed to simulate similar processes that occur in rhizosphere, i.e. small-chain organic acids induce the reconformation of soil organic matter thereby releasing biologically active aggregates/molecules promoting the plant growth. In the first step, the produced modified humic acids (MHA) were characterised for their physico-chemical properties and molecular structure of by using elemental analysis (EA), Fourier-transformed infrared (FTIR) spectroscopy, high-pressure size exclusion chromatography (HPSEC), surface tension measurement and gas chromatography-mass spectrometry (GC-MS) analysis. In the second step, the parameters of biological activity were obtained from experiments oriented to both higher plants and remediation of microbiological activity in used soil. The biological activity towards higher plants was conducted on maize seeds and represented by total mass and length increments of roots, root division and sugars and protein contents. The influence on used soil was determined by laboratory soil incubation (CO2 production) and soil water repellency measurement (contact angle). All results were subjected to statistical analysis using Pearson´s correlation coefficient to find relationship between physico-chemical properties and biological activity of studied HAs samples. The results showed correlations between biological activity and physico-chemical properties of humic acids. On the contrary, the surface properties did not show any correlations with physical-chemical properties of studied HAs. The most efficient modifier in terms of biological activity was 20% formic acid and the less efficient was 20% propionic acid.
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Production, Characterization and Design of Applications of Regenerated Humic Acids
David, Jan ; Grasset, Laurent (oponent) ; Taraba, Boleslav (oponent) ; Novotná, Miroslava (oponent) ; Kučerík, Jiří (vedoucí práce)
Submitted thesis deals with the humic substances, namely the humic acids and their salts, i.e. potassium humates. A literature review about humic substances is presented, the brief history of their research, their structure issues, supramolecular arrangement and applications. A special attempt is paid to review methods of extractions of humic acids from various sources. Further, the papers concerning biological, hormone-like properties are listed and discussed. From the environmental chemistry point of view mainly sorption properties are overviewed. Industrial applications of humics are covered by a wide range of patents and published works such as for instance dyes, polymer additives, etc. In experimental part, the regeneration of lignite and preparation of humic acids and their salts is described. The regeneration principle lies in the oxidation of parental lignite with a range of concentrations of nitric acid and hydrogen peroxide. Novel approach is presented in the characterization humic substances, where the chemical characteristics like Elemental Analysis, Fourier Transform Infra-red Spectroscopy and Thermogravimetry are followed by physico-chemical assessments (Dynamic Light Scattering, Fast Field Cycling Nuclear Magnetic Resonance Relaxometry, High Performace Size Exclusion Chromatography and Fluorescence Spectroscopy in combination with research of humates hydration by means of High Resolution Ultrasonic Spectrometry and Densitometry). These chemical and physico-chemical characteristics are put into the correlation with the biological characteristics, i.e. biological activity of humates, which is assessed by a slightly modified method based on the determination of maize roots weight, length and number of lateral roots. Finally, the statistical approach is applied via Pearson’s correlation coefficient and as a pilot studies, two environmental applications of regenerated humic materials are designed, in the field of sorption of tetracycline antimicrobial and researching of regenerated lignited as a potential source of fermentable sugars.
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Chemical and Physical Transformations of Humic Acids
Vlčková, Zoja ; Pospíšilová, Ľubica (oponent) ; Janoš,, Pavel (oponent) ; Pekař, Miloslav (vedoucí práce)
This work is a pilot study testing the relationships between biological properties and structure of humic acids extracted from original and modified South-Moravian lignite, mine Mír, Mikulčice. In first part of the work, methods suitable for increase of the humic acid yield were explored. Lignite oxidation in gas phase turned out to be relatively instrumentally demanding and insufficiently effective. Therefore, only oxidation in liquid phase was explored further along with modification with short-chained organic acids. Modification with short-chained organic acids was inspired by processes enhancing biological functions in rhizosphere, i.e. the root system produces exudates causing changes in the supramolecular structure of the surrounding organic matter, improving its mobility and cell-walls penetration. Primary structure of humic acids produced in this work was investigated by elemental analysis, solid state NMR, EPR and UV-VIS spectroscopy. Despite the fact that only minor differences were found, conducted assessment of biological activity and genotoxic potential showed that humic acids and their respective humates isolated from lignite with different pre-treatment show different bioactivity. Therefore, supramolecular structure of samples in diluted solutions was investigated by means of HPSEC, HRUS and densitometry measurements. Two counterions – potassium and ammonium – were tested. Obtained results confirm the assumption that observed quality of humates depends on counterion, concen-tration of humate and also on the method of lignite pre-treatment. Both selected pre-treatment methods showed potential to produce humic acids with variable biological properties, applicable in agriculture, environmental chemistry and potencially also in pharmacology.
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Studium botnavosti a biologické aktivity hydrogelů huminových kyselin
Kozelková, Aneta ; Hynšt, Jaroslav (oponent) ; Sedláček, Petr (vedoucí práce)
Tato diplomová práce se zabývá studiem biologické aktivity huminových látek. Na základě literární rešerše byly optimalizovány metody přípravy hydrogelových aplikačních forem s obsahem huminových látek a biopolymerů s vysokou bobtnavostí a byla navržena a otestována metodika pro rychlé a experimentálně nenáročné posouzení biologické aktivity získaných materiálů v laboratorních podmínkách. Náplní experimentální části je charakterizace hydrogelových vzorků základními fyzikálně-chemickými metodami, hlavní pozornost byla věnována sorpci vody a uvolňování huminové složky. Poté byly připravené hydrogelové materiály otestovány z hlediska jejich vlivu na růst kukuřice seté v půdě. Byl také studován vliv připravených hydrogelových forem na vstřebávání minerálních živin kořeny rostlin. Motivace této práce je založena na využití těchto hydrogelových materiálů v zemědělství a současně i v ochraně životního prostředí, neboť je snahou navrátit do půdy chybějící přirozenou organickou složku v podobě materiálu s postupným uvolňováním aktivní látky a zastavit tak pozvolnou degradaci půd.
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Phosphanucleosides containing 1-hydroxymethylphospholane 1-oxide ring
Páv, Ondřej ; Zborníková, Eva ; Buděšínský, Miloš ; Rosenberg, Ivan
Novel phosphanucleosides containing 1-hydroxymethylphospholane 1-oxide ring were synthesized as compounds with potential biological activity. A ring-closing metathesis was employed to prepare a phospholene precursor, which was then converted into either 4-azido-3-hydroxy-1-hydroxymethylphospholane 1-oxide or 3-azido-1- hydroxymethylphospholane 1-oxide derivatives. Subsequently, nucleobase was introduced using a nucleobase construction. The biological activity of prepared compounds was evaluated.
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Sledování biologické aktivity včel
MACHART, Luboš
Tato bakalářská práce se zabývá tématem sledování biologické aktivity včel. Její hlavní části je nalezení a prozkoumání stavu této oblasti a to pomocí dotazníkového průzkumu. Tento průzkum jsem aplikoval na dostatečný počet respondentů a podle jeho vyhodnocení optimalizoval a navrhnul vhodné řešení pro sledování objemu vyprodukovaného medu v úlech. Dotazník jsem koncipoval tak, aby bylo možné výsledné řešení co nejvíce přiblížit trhu a tak umožnit sledování úlů na dálku co největšímu počtu včelařů. Zařízení pro přenos dat jsem tedy vybíral podle jasně daných kritérií. Výsledný návrh by bylo možné po dalším propracování uvést do praxe a pokračovat ve výzkumu se zajímavými daty.
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Full biological characterization of two linear vasopressin analogues - [Phaa,D-Tyr(Et).sup.2./sup.,Aib.sup.4./sup.,Arg.sup.6./sup.,Tyr(NH.sub.2./sub.).sup.9./sup.]AVP and [Phaa,D-Tyr(Et).sup.2./sup.,Arg.sup.6./sup.,Aib.sup.7./sup.,Tyr(NH.sub.2./sub.).sup.9./sup.]AVP
Kunčarová, Pavla ; Nazarov, Elšan ; Howl, J. ; Slaninová, Jiřina
The achiral amino acid Aib was introduced into position 4 or 7 of the linear V1a-selective vasopressin antagonist [Phaa,D-Tyr(Et)2,Arg6,Tyr(NH2)9]AVP. Peptides displayed reduced affinities for both V1a and V2 receptors and high antipressor activity in vivo. Uterotonic tests in vitro revealed that these compounds also strongly interact with the oxytocin receptor (pA2=7.8 and 7.9 for Aib4 and Aib7, respectively).
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