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Thesis (Ph.D. (Agriculture)) --University of Limpopo (Turfloop Campus), 2005 / Drying, grinding and sieving are commonly employed to facilitate the handling, storage of soil samples on which chemical, biological, and physical analyses are to be performed. These laboratory protocols have the potential to alter soil chemical characteristics and may result in unrealistic estimates of in situ chemical processes. The effect of laboratory soil sample preparation on level of extractable Ca, Mg, K, and P was determined. The analyses were done on laboratory prepared soil samples and compared with the characteristics of fresh soil samples (field-moist) for the same soils that were sampled in pairs of 20 per location of the four locations. Samples were collected at Tshiombho irrigation scheme, Dal water farm, Magoebaskloef pine tree farm and Syferkuil experimental farm. The results indicated that soil samples should be kept at their field moist status until experimental procedures are done. Concentration of most extractable ions for the two preparation methods correlated closely. However, grinding and air-drying increased P concentration by 1.3 to 1.55 times, and decreased the concentration of K by 2 to 2.5 times and this is caused by soil moisture depletion. According to the results, there should be different preparation methods for different extractable ions, Ca and Mg can be continued analysed on laboratory prepared soil samples but soil pH, K and P should be analysed on fresh soil samples. If such is not done, then the effects should be considered when interpreting the results for fertilizer recommendations. / NRF

In case of a release of radioactive nuclides into the environment it is necessary to  have reliable methods to estimate the potential effect on people and the ecosystem. In this context the total activity deposited, the elemental composition and the depth distribution are of importance. An efficient in situ method to estimate the average contamination over larger areas using high purity germanium (HPGe) detectors has been developed. The method combines simulation of photon transport with measured detector properties. The total activity of 137Cs determined from gamma-ray spectra recorded in situ are compared to results from soil sampling. Another in situ method has been developed to determine the depth distribution of a radionuclide contamination, using an array of small detectors inserted into the ground, as an alternative to the standard procedure of soil sampling. The possibility to use cadmium telluride (CdTe) detectors as well as lanthanum bromide (LaBr3) detectors has been investigated. As a demonstration of the developed method the small-scale variation of the activity distributions in an area covering 350 m2 have been measured and is compared to results obtained by other methods. / At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Submitted.

Submitted by Natíza Graziele Martins Borsato null (natiza_gmb@hotmail.com) on 2017-09-22T13:29:54Z No. of bitstreams: 1 DEFESA Natiza G M Borsato.pdf: 2718459 bytes, checksum: 27005db75663dcc081fd9ab405793b95 (MD5) / Rejected by Monique Sasaki (sayumi_sasaki@hotmail.com), reason: Solicitamos que realize uma nova submissão seguindo a orientação abaixo: O arquivo submetido está sem a ficha catalográfica. A versão submetida por você é considerada a versão final da dissertação/tese, portanto não poderá ocorrer qualquer alteração em seu conteúdo após a aprovação. Corrija esta informação e realize uma nova submissão contendo o arquivo correto. Agradecemos a compreensão. on 2017-09-27T18:30:18Z (GMT) / Submitted by Natíza Graziele Martins Borsato null (natiza_gmb@hotmail.com) on 2017-10-04T02:10:48Z No. of bitstreams: 1 DEFESA Natiza G M Borsato.pdf: 2725342 bytes, checksum: 2ca43e2f0da0345b3a705c0777b90ef3 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-10-04T17:27:11Z (GMT) No. of bitstreams: 1 borsato_ngm_me_sjrp.pdf: 2725342 bytes, checksum: 2ca43e2f0da0345b3a705c0777b90ef3 (MD5) / Made available in DSpace on 2017-10-04T17:27:11Z (GMT). No. of bitstreams: 1 borsato_ngm_me_sjrp.pdf: 2725342 bytes, checksum: 2ca43e2f0da0345b3a705c0777b90ef3 (MD5) Previous issue date: 2017-08-11 / No presente trabalho estudou-se, a concentração de bismuto total em áreas com falhas tectônicas e sua correlação com os níveis de radioisótopos de chumbo e de emissão de radônio-222. As determinações de bismuto total em diferentes solos foram realizadas por análise eletroquímica pela técnica de voltametria de redissolução anódica. Os valores de bismuto total aumentaram de acordo com o aumento da profundidade na extração do solo em estudo. Evidenciando a existência de bismuto decorrente da emanação de radônio-222 e sugerindo a existência de falhas geológicas nas áreas estudadas. Por análise estatística (ANOVA) verificou-se uma correlação da concentração de chumbo total e o nível de emissão de radônio-222 com a concentração de bismuto total. Essa correlação indica que a fonte de bismuto é proveniente da cadeia de decaimento radioativo do urânio-238 e tório-232. / In this work, the total concentration of bismuth areas with tectonic faults and their correlation and their correlation with the levels of lead radioisotopes and radon-222 emission. The determination of total bismuth in different soils were performed by electrochemical analysis using anodic redissolution voltammetry technique. The total bismuth values increased according to the depth increase in the extraction of the soil under study, evidencing the existence of bismuth due to the emanation of radon-222 and suggesting the existence of geological faults in the studied areas. Statistical analysis (ANOVA) showed a correlation between the total lead concentration and the emission level of radon-222 with the total bismuth concentration. This correlation indicates that the bismuth source is from the radioactive decay chain of uranium-238 and thorium-232.

Soil microorganisms play important roles in maintaining soil quality and ecosystem health. Development of effective methods for studying the composition, diversity, and behavior of microorganisms in soil habitats is essential for a broader understanding of soil quality. Forest management strategies and practices are of vital significance for sustainable forest production. How the different forest management measures will influence soil microbial communities is a widespread concern of forest industry and scientific communities. Only a small proportion (~0.1%) of the bacteria from natural habitats can be cultured on laboratory growth media. Direct extraction of whole-community DNA from soil, followed by polymerase chain reaction (PCR) and other analysis circumvents the problems of the culture-dependent methods and may shed light on a broader range of microbial communities in the soil. DNA-based molecular methods rely on high quality soil microbial DNA as template, and thus extraction of good quality DNA from soil samples has been a challenge because of the complex and heterogeneous nature of the soil matrix. The objectives of this research were to establish a set of DNA-based molecular methods and to apply them to investigate forest soil microbial composition and diversity. Soil samples were collected from different forest ecosystems, i.e., the natural forest (YNF) and the first rotation (~ 50 years) (Y1R) and the second rotation (~ 1 year) (Y2R) of hoop pine plantations at Yarraman, and from different forest residue management practices (the experiments had established 6.4 years before the samples were collected) at Gympie, two long-term experimental sites of the Queensland Department of Primary Industry-Forestry in subtropical Queensland, Australia. Some DNA-based molecular techniques, including DNA extraction and purification, PCR amplification, DNA screening, cloning, sequencing and phylogenetic analyses, were explored using Yarraman soil samples, which were high in organic matter, clay and iron oxide contents. A set of methods was assembled based on the recommendations of the method development experiments and applied to the investigations of the microbial composition and diversity of the Yarraman and Gympie soil samples. Four soil DNA extraction methods, including the Zhou method (Zhou et al., 1996), the Holben method (Holben, 1994), the UltraClean (Mo Bio) and FastDNA (Bio 101) soil DNA extraction kits, were explored. It was necessary to modify these methods for Yarraman soil. I designed and introduced a pre-lysis buffer washing step, to partially remove soil humic substances and promote soil dispersion. This modification greatly improved the quality of the extracted DNA, decreasing co-extracted humic substances by 31% and increasing DNA yield by 24%. The improved Holben method was recommended for fungal community studies, and the improved Zhou method for bacterial community studies. The extracted DNA was good in quality, with a consistent size of ~20 kb and a yield of 48-87 g g-1 soil, and could be successfully used for 16S (Zhou method) and 18S (Holben method) rDNA amplifications. For less difficult environmental samples, UltraClean kits could be a good option, because they are simple and fast and the extracted DNA are also of good quality. Screening of the DNA PCR products using TGGE, Heteroduplex-TGGE and SSCP was also explored. These methods were not so effective for the screening of the soil DNA PCR products, owing to the difficulty in interpretation of the results. Cloning was a necessary step to obtain a single sequence at species level in soil microbial community studies. The screening of the clone library by TGGE, Heteroduplex-TGGE and SSCP could only separate the clones into several major bands, although SSCP gave better separation. Sequencing of selected clones directly from the clone library obtained ultimate results of microbial taxonomic composition and diversity through well-established sequence analysis software packages and the databases. It was recommended that, in this project with the target of microbial community composition and diversity, soil DNA PCR products were directly cloned to construct clone libraries and a sample of clones were sequenced to achieve an estimate of the taxonomic composition of the soil. Fungal communities of the Yarraman soil samples under the natural forest (YNF) and the hoop pine plantations (YHP) were investigated using 18S rDNA based cloning and sequencing approaches. Twenty-eight clone sequences were obtained and analysed. Three fungal orders, i.e., Zygomycota, Ascomycota and Basidiomycota were detected from the YNF and YHP samples. By contrast, culture-based analyses of fungi in the literature were mostly Ascomycetes. YNF appeared to have more Ascomycota but less Zygomycota than YHP, and within the Zygomycota order, YHP had more unidentified species than YNF. Bacterial communities of Yarraman soil samples of YNF, Y1R and Y2R were investigated using 16S rDNA-based cloning and sequencing approaches. 305 16S rDNA clone sequences were analysed and showed an overall bacterial community composition of Unclassified bacteria (34.4%), Proteobacteria (22.0%), Verrucomicrobia (15.7%), Acidobacteria (10.2%), Chloroflexi (6.9%), Gemmatimonadetes (5.6%), and Actinobacteria (5.2%). There was a significant difference among YNF, Y1R and Y2R in the taxonomic group composition. YNF had a greater proportion of Acidobacteria (18.0%), Verrucomicrobia (23.0%) and Chloroflexi (9.0%) than Y1R and Y2R (corresponding to 6.3%, 12.1% and 5.9%, respectively), while Y1R and Y2R had a higher percentage of the Unclassified group (38.5% for Y1R and 46.5% for Y2R) than YNF (18.0%). For the Proteobacteria group, YNF had more Alpha-subdivision but Y1R and Y2R had more Delta-subdivision. From YNF to Y1R to Y2R, the clone sequence variable site ratios, 5% and 10% OTU numbers and Shannon's diversity index H' values tended to decrease, indicating the soil bacterial diversity decreased from the natural forest to the first and the second rotation hoop pine plantations. The large amount of unclassified clone sequences could imply a novel group of bacteria in the soil, particularly in the hoop pine soil samples. Alternatively they may result from artefacts during the PCR process. Bacterial communities of the Gympie soil under different residue management practices, i.e., residue (litter plus logging residue) removed (G0R), residue retained (G1R), and residue doubled (G2R), were also investigated using the 16S rDNA-based cloning and sequencing approaches. Acidobacteria (37.6%) and Proteobacteria (35.6%, including Alpha-subdivision of 29.9% and Gamma-subdivision of 5.7%) were dominant components of the communities, followed by Actinobacteria (14.7%), Verrucomicrobia (7.3%) and Unclassified bacteria. There was no significant difference among G0R, G1R and G2R in the bacterial community compositions and diversity. These findings provided an in-depth vision of the soil microbial communities under different forest management practices. Their combination with other soil analysis results, such as physical and chemical properties, and forest production data, could provide an improved understanding of sustainable forest management strategies.

Sigtuna is one of the first settlements in Sweden considered to be a proper town. Taking over Birka´s function as a central trading hub when it was founded in the late 10th century AD, Sigtuna was characterized by its early connection to Christianity, and many churches were built there. The foundations of one of these medieval stone churches and its churchyard lie beneath Sigtuna museum’s plot on the block S: t Gertrud 3. However, the full extent of this church and churchyard as well as its foundation date and function is not fully known. The over-arching purpose of this study is to achieve a better understanding of this church’s function. This will be done by geochemically analysing soil samples taken from the museum plot under which the churchyard is located. The first aim of this study is to establish the extent of the churchyard. During excavations carried out between 1990- 1991 in the neighbouring block Urmakaren, archaeologists discovered the remains of King Olof Skötkonung’s minting house along with various finds, notably two lead pieces with imprints of coin stamps. The second aim of this study is to see if traces of these metalworking activities can be detected on the museum plot. The third aim is to see how the church and churchyard related to the minting house on a spatial plane.

O solo é um compartimento ambiental altamente complexo e, em razão do crescimento populacional acelerado e da intensa atividade industrial e agrícola, tem sofrido com a contaminação de substâncias de origens diversas. Entre as principais atividades que contribuem para a perturbação da qualidade dos solos estão as atividades de geração de energia pela queima de combustíveis fósseis, como o carvão mineral. Dentre as substâncias presentes nos rejeitos do carvão queimado em usinas termelétricas estão compostos orgânicos e metais pesados que interagem com o material genético, produzindo mutações e acarretando prejuízos em nível de organismo (como as neoplasias), mas também em níveis maiores de organização biológica (como a perda de diversidade genética em populações). Estudos de avaliação do potencial mutagênico em amostras de solo são escassos, principalmente investigando a ação de mutágenos de origem inorgânica. Além disso, estudos de mutagênese em solos sob a influência de rejeitos de carvão têm sido pouco abordados na literatura. Desta forma, os objetivos deste trabalho foram: (i) testar um protocolo para avaliação de atividade mutagênica em extratos inorgânicos e orgânicos de solo; (ii) avaliar a presença e o perfil dos compostos mutagênicos em solos sob a influência de cinzas de carvão e (iii) investigar as rotas ambientais para dispersão dos compostos mutagênicos na área de estudo. Para atingir estes objetivos, processos de extração de compostos orgânicos e inorgânicos de solo foram testados quanto a sua eficiência em extrair da amostra compostos potencialmente mutagênicos frente a linhagem de Salmonella typhimurium que detecta erro no quadro de leitura (TA98). Os protocolos mais eficientes foram utilizados para os testes com diferentes amostras de solo sob a influência de rejeitos de carvão utilizando diversas linhagens, na ausência e presença de ativação metabólica (fração S9 mix). Os resultados de mutagênese associados aos resultados da caracterização química de compostos orgânicos e metais indicaram que os contaminantes presentes nas cinzas de carvão podem se dispersar com facilidade para áreas adjacentes. Essa abordagem de estudo permitiu relacionar a presença de determinadas classes de compostos com diferentes danos no DNA e inferir distintas rotas ambientais de dispersão para esses compostos. A realização deste trabalho ressalta a importância de estudos em matrizes ambientais complexas, em especial solos contaminados, que buscam integrar os dados de mutagênese e utilizá-los sob uma perspectiva ecológica. / Soil is a highly complex environmental compartment that has suffered contamination by substances from multiple sources mainly due to fast population growth and intense industrial and agricultural activity. Among the main activities that affect soil quality are power generation activities that use fossil fuels, such as mineral coal. Among the several compounds present in coal ashes that are employed in coal-fired power plants are substances that interact with the genetic material, causing mutations and/or damage at the individual level (like neoplasias) but also at higher levels of biological organization (like loss of genetic diversity in populations). There are few studies on the mutagenic potential of soil samples, especially those that investigate the action of mutagens from inorganic sources. Moreover, studies of mutagenesis in soils under the influence of coal-fired power plants have rarely been reported in literature. Thus, this work aimed at: (i) testing a protocol for the evaluation of mutagenic activity in inorganic and organic extracts from soil samples; (ii) evaluating the presence and the profile of mutagenic compounds in soils under the influence of coal ashes and (iii) investigating environmental routes of dispersion of mutagenic compounds in the study area. In order to achieve these aims, extraction processes for inorganic and organic compounds were tested concerning their efficiency to extract compounds potentially mutagenic to the specific Salmonella typhimurium strain that detects frameshift mutagens (TA98). The most efficient protocols were further utilized for the tests with different soil samples under the influence of coal-fired power plant using several strains, in absence and presence of metabolic activation (S9 mix fraction). Mutagenesis results associated with the chemical characterization of the organic compounds and metals indicated that contaminants present in coal ashes can be easily dispersed to adjacent areas. This approach allowed relating the presence of certain classes of compounds to specific damages in DNA and inferring distinct dispersion routes for these compounds. This work highlights the importance of studies concerning complex environmental matrices, specially contaminated soils, which seek the integration of mutagenesis data and their use from an ecological perspective.

Made available in DSpace on 2014-06-11T19:35:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-05-19Bitstream added on 2014-06-13T18:46:19Z : No. of bitstreams: 1 bellin_ic_dr_araiq.pdf: 1668200 bytes, checksum: bca88ddf4d8550b63d36e4e2d483f6cb (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Neste trabalho caracterizaram-se amostras de solo e substâncias húmicas (SH) extraídas de diferentes solos da Bacia do Médio Rio Negro e também determinaram-se a capacidade de complexação de íons Hg(II) por SH e constantes de troca entre espécies metálicas originalmente complexadas às SH por íons Hg(II). As amostras de solos foram caracterizadas através do teor de matéria orgânica, análises elementar e granulométrica. Os resultados mostraram que os teores de matéria orgânica para as amostras de solo diminuíram com a profundidade. Com base nos resultados de análise granulométrica feita nas amostras de solos, caracterizou-se o aumento dos teores de argila em função da profundidade com a conseqüente diminuição dos teores de areia e silte. As substâncias húmicas extraídas de amostras de solos coletados na Bacia do Médio Rio Negro-AM foram caracterizados por análise elementar, ressonância paramagnética eletrônica e ressonância magnética nuclear. Os resultados mostraram que, em função da profundidade, os valores das razões atômicas C/N foram praticamente constantes ao contrário das razões C/O e C/H, as quais diminuíram. As concentrações de radicais livres do tipo semi-quinona das substâncias húmicas variaram de 0,08 a 5,38 x 1018 spins g-1 de carbono, indicando diferença entre os níveis de humificação das SH extraídas de solos amazônicos. As SH extraídas de solos de regiões alagáveis apresentaram maiores concentrações de spins em relação às SH extraídas de regiões não alagáveis, indicando influência da umidade no processo de humificação. / In this research were characterized humic substances (HS) and soil samples extracted from Rio Negro-AM Medium Basin and capacity of complexation (CC) of Hg(II) by HS and constants of exchange between metallic species originally complexed in the HS by Hg(II) had also been determined. The soil samples were characterized through organic material composition, elemental and granulometry analysis. The results showed decreasing of the organic material composition with the depth. According to the results taken, was characterized an increasing in the composition of clay with the depth, but in the other hand, a reduction in silt and sand composition. The humic substances extracted of soil samples from Rio Negro-AM Medium Basin were characterized by elemental analysis, electronic paramagnetic resonance and nuclear magnetic resonance. The results had shown that, in function of the depth, the atomic ratio values C/N were constants, while the atomic ratio C/O and C/H decresed. The concentrations of free radicals of the humic substances were 0.08 to 5.38 x 1018 spins g-1 of carbon, indicating difference in the humification levels of HS extracted from Amazonian soils. The HS extracted in flooded regions showed bigger spins concentrations comparing to ones extracted in unflooded regions, showing that the humidity influences in the process of humification. The NMR of 13C dates showed the sequence of percentage of kind of carbon: aliphatic > ethers/hydroxyls > carboxyls/esthers/amides > aromatics > phenols @ carbonyls of aldehydes and ketones for HS samples extracted of the differences profiles of the Amazonian soils studied.

O solo é um compartimento ambiental altamente complexo e, em razão do crescimento populacional acelerado e da intensa atividade industrial e agrícola, tem sofrido com a contaminação de substâncias de origens diversas. Entre as principais atividades que contribuem para a perturbação da qualidade dos solos estão as atividades de geração de energia pela queima de combustíveis fósseis, como o carvão mineral. Dentre as substâncias presentes nos rejeitos do carvão queimado em usinas termelétricas estão compostos orgânicos e metais pesados que interagem com o material genético, produzindo mutações e acarretando prejuízos em nível de organismo (como as neoplasias), mas também em níveis maiores de organização biológica (como a perda de diversidade genética em populações). Estudos de avaliação do potencial mutagênico em amostras de solo são escassos, principalmente investigando a ação de mutágenos de origem inorgânica. Além disso, estudos de mutagênese em solos sob a influência de rejeitos de carvão têm sido pouco abordados na literatura. Desta forma, os objetivos deste trabalho foram: (i) testar um protocolo para avaliação de atividade mutagênica em extratos inorgânicos e orgânicos de solo; (ii) avaliar a presença e o perfil dos compostos mutagênicos em solos sob a influência de cinzas de carvão e (iii) investigar as rotas ambientais para dispersão dos compostos mutagênicos na área de estudo. Para atingir estes objetivos, processos de extração de compostos orgânicos e inorgânicos de solo foram testados quanto a sua eficiência em extrair da amostra compostos potencialmente mutagênicos frente a linhagem de Salmonella typhimurium que detecta erro no quadro de leitura (TA98). Os protocolos mais eficientes foram utilizados para os testes com diferentes amostras de solo sob a influência de rejeitos de carvão utilizando diversas linhagens, na ausência e presença de ativação metabólica (fração S9 mix). Os resultados de mutagênese associados aos resultados da caracterização química de compostos orgânicos e metais indicaram que os contaminantes presentes nas cinzas de carvão podem se dispersar com facilidade para áreas adjacentes. Essa abordagem de estudo permitiu relacionar a presença de determinadas classes de compostos com diferentes danos no DNA e inferir distintas rotas ambientais de dispersão para esses compostos. A realização deste trabalho ressalta a importância de estudos em matrizes ambientais complexas, em especial solos contaminados, que buscam integrar os dados de mutagênese e utilizá-los sob uma perspectiva ecológica. / Soil is a highly complex environmental compartment that has suffered contamination by substances from multiple sources mainly due to fast population growth and intense industrial and agricultural activity. Among the main activities that affect soil quality are power generation activities that use fossil fuels, such as mineral coal. Among the several compounds present in coal ashes that are employed in coal-fired power plants are substances that interact with the genetic material, causing mutations and/or damage at the individual level (like neoplasias) but also at higher levels of biological organization (like loss of genetic diversity in populations). There are few studies on the mutagenic potential of soil samples, especially those that investigate the action of mutagens from inorganic sources. Moreover, studies of mutagenesis in soils under the influence of coal-fired power plants have rarely been reported in literature. Thus, this work aimed at: (i) testing a protocol for the evaluation of mutagenic activity in inorganic and organic extracts from soil samples; (ii) evaluating the presence and the profile of mutagenic compounds in soils under the influence of coal ashes and (iii) investigating environmental routes of dispersion of mutagenic compounds in the study area. In order to achieve these aims, extraction processes for inorganic and organic compounds were tested concerning their efficiency to extract compounds potentially mutagenic to the specific Salmonella typhimurium strain that detects frameshift mutagens (TA98). The most efficient protocols were further utilized for the tests with different soil samples under the influence of coal-fired power plant using several strains, in absence and presence of metabolic activation (S9 mix fraction). Mutagenesis results associated with the chemical characterization of the organic compounds and metals indicated that contaminants present in coal ashes can be easily dispersed to adjacent areas. This approach allowed relating the presence of certain classes of compounds to specific damages in DNA and inferring distinct dispersion routes for these compounds. This work highlights the importance of studies concerning complex environmental matrices, specially contaminated soils, which seek the integration of mutagenesis data and their use from an ecological perspective.