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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.
61

ESTUDO QUÍMICO DA PRÓPOLIS DOS CAMPOS GERAIS DO PARANÁ

Cordeiro, Adriana Rute 30 August 2013 (has links)
Made available in DSpace on 2017-07-24T19:38:10Z (GMT). No. of bitstreams: 1 Adriana Rute Cordeiro.pdf: 1697344 bytes, checksum: c49bee8f561162a88549115390df463d (MD5) Previous issue date: 2013-08-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study aimed to develop methods for obtaining extracts for the isolation and chemical analysis of propolis using two samples from the region known as “Campos Gerais do Paraná”. One of the studied propolis samples was produced in the district of Ipiranga and another in the municipality of Ponta Grossa. The utilized general fractionation method allowed obtaining from the same sample the essential oils and then the aqueous extracts and various organic fractions containing chemical components of several polarities. The analyses of the essential oils showed that both samples of propolis contain several components found in Baccharis dracunculifolia, known as vassoura or alecrim do campo, indicating that these are similar to those of green propolis produced in southeastern Brazil. The analyses also demonstrated the presence of phenol compounds such as flavonoids and caffeoylquinic acids, pointing once again that the botanical origin of both propolis includes the alecrim do campo. The analyses of essential oils originating from Ipiranga propolis sample indicated spathulenol and (E)-nerolidol as the main components, while the one acquired in Ponta Grossa showed high proportions of two substances containing aromatic rings in their structures, 2,6-di-t-butyl-p-cresol and benzyl benzoate. The two sesquiterpene alcohols spathulenol and (E)-nerolidol are commonly found in essential oils from B. dracunculifolia and appear in propolis from Ponta Grossa in low percentages, while the two mentioned aromatic compounds are not commonly found in the genus Baccharis. The various analyses of extracts and isolates showed that two aromatic acids may be considered as marker substances for both samples of propolis. The para-hydroxycinnamic acid seemed to be characteristic of propolis from Ipiranga, while the benzoic acid could be considered typical of the sample from Ponta Grossa. Atomic absorption spectrometry analyses that were conducted with both studied propolis did not indicate neither high levels of essential minerals nor the presence of heavy metals, and this fact represents a guarantee that producers have been working in clean environments. / Este estudo buscou desenvolver métodos para a obtenção de extratos destinados ao isolamento e análises químicas de própolis utilizando duas amostras provenientes da Região dos Campos Gerais do Paraná. Uma das amostras de própolis estudadas foi produzida no município de Ipiranga e a outra no município de Ponta Grossa. O método geral de fracionamento utilizado permitiu obter, de uma mesma amostra, os óleos essenciais e em seguida o extrato aquoso e diversos extratos orgânicos contendo substâncias de várias polaridades. As análises dos óleos essenciais demonstraram que ambas as amostras de própolis contém vários componentes também presentes na espécie vegetal Baccharis dracunculifolia, conhecida como vassoura ou alecrim do campo, indicando tratar-se da chamada própolis verde, similares às produzidas na região sudeste do Brasil. As análises também demonstraram a presença de substâncias fenólicas, tanto flavonoides como ácidos cafeoilquínicos, reforçando que a origem botânica das própolis analisadas inclui o alecrim dos campos. As análises de óleos essenciais da amostra de Ipiranga indicaram como componentes principais o espatulenol e o (E)-nerolidol, enquanto que as de Ponta Grossa apresentaram altas proporções de duas substâncias contendo anéis aromáticos em suas estruturas, o 2,6-di-t-butil-p-cresol e o benzilbenzoato. Os dois álcoois sesquiterpênicos espatulenol e (E)-nerolidol são encontrados comumente em óleos essenciais de B. dracunculifolia e aparecem na própolis de Ponta Grossa em baixas porcentagens, enquanto que os dois mencionados compostos aromáticos não são tão comuns em espécies do gênero Baccharis. As diversas análises de extratos e isolamentos demonstraram que dois ácidos aromáticos podem ser considerados como substâncias marcadoras das duas amostras de própolis analisadas. O ácido para-hidroxicinâmico mostrou-se característico da própolis de Ipiranga, enquanto que o ácido benzóico pode ser considerado típico da amostra de Ponta Grossa. As análises por espectrometria de absorção atômica que foram conduzidas com ambas as própolis estudadas não indicaram níveis elevados de metais e nem a presença de metais pesados inconvenientes, sendo mais uma garantia de que os produtores estão trabalhando em ambientes limpos quanto a este aspecto.
62

Effects of cow urine and its constituents on soil microbial populations and nitrous oxide emissions

Bertram, Janet January 2009 (has links)
New Zealand’s 5.3 million strong dairy herd returns approximately 106 million litres of urine to pasture soils daily. The urea in that urine is rapidly hydrolysed to ammonium (NH₄⁺), which is then nitrified, with denitrification of nitrate (NO₃⁻) ensuing. Nitrous oxide (N₂O), a potent greenhouse gas (GHG), is produced via nitrification and denitrification, which are enzyme-catalysed processes mediated by soil microbes. Thus microbes are linked intrinsically to urine patch chemistry. However, few previous studies have investigated microbial dynamics in urine patches. Therefore the objective of these four experiments was to investigate the effects on soil microbial communities of cow urine deposition. Methods used included phospholipid fatty acid (PLFA) analyses of microbial community structure and microbial stress, dehydrogenase activity (DHA) assays measuring microbial activity, and headspace gas sampling of N₂O, ammonia (NH₃) and carbon dioxide (CO₂) fluxes. Experiment 1, a laboratory study, examined the influence of soil moisture and urinary salt content on the microbial community. Both urine application and high soil moisture increased microbial stress, as evidenced by significant changes in PLFA trans/cis and iso/anteiso ratios. Total PLFAs and DHA showed a short-term (< 1 week) stimulatory effect on microbes after urine application. Mean cumulative N₂O-N fluxes were 2.75% and 0.05% of the nitrogen (N) applied, from the wet (70% WFPS) and dry (35% WFPS) soils, respectively. Experiment 2, a field trial, investigated nutrient dynamics and microbial stress with plants present. Concentrations of the micronutrients, copper, iron and molybdenum, increased up to 20-fold after urine application, while soil phosphorus (P) concentrations decreased from 0.87 mg kg ⁻¹ to 0.48 mg kg⁻¹. Plant P was also lower in urine patches, but total PLFAs were higher, suggesting that microbes had utilised the available nutrients. Microbial stress again resulted from urine application but, in contrast to experiment 1, the fungal biomass recovered after its initial inhibition. Studies published during the course of this thesis reported that hippuric acid (HA) and its hydrolysis product benzoic acid (BA) significantly reduced N₂O-N emissions from synthetic cow urine, thus experiment 3 investigated this effect using real cow urine. Cumulative N₂O-N fluxes were 16.8, 5.9 and 4.7% of N applied for urine (U) alone, U+HA and U+BA, respectively. Since NH₃-N volatilisation remained unchanged, net gaseous N emissions were reduced. Trends in total PLFAs and microbial stress were comparable to experiment 1 results. Experiment 4 studied HA effects at different temperatures and found no inhibition of N₂O-N fluxes from HA-amended urine. However, mean cumulative N₂O-N fluxes were reduced from 7.6% of N applied at 15–20°C to 0.2% at 5–10°C. Total cumulative N emissions (N₂O-N + NH₃-N) were highest at 20°C (17.5% of N applied) and lowest at 10°C (9.8% of N applied). Microbial activity, measured as potential DHA, increased with increasing temperature. This work has clearly shown that the stimulation and inhibition of the soil microbial community by urine application are closely linked to soil chemistry and have significant impacts not only on soil nutrient dynamics but also on N₂O-N emissions and their possible mitigation.

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