O presente trabalho teve por objetivo avaliar o efeito do alumínio sobre a fermentação alcoólica utilizando diferentes linhagens industriais de leveduras (CAT-1, BG-1, PE-2, Fleischmann e colônias de leveduras selvagens isoladas do processo de produção de álcool combustível denominadas C1, C5, C6, C8, C10 e C11) em diferentes concentrações de alumínio e também analisar o acúmulo do metal nessas leveduras durante o processo fermentativo com reciclos de células, semelhante ao processo industrial, para tal, foram avaliados parâmetros como: produção de etanol, rendimento fermentativo, formação de biomassa, produção de glicerol, utilização da trealose, eficiência fermentativa e acúmulo de Al pelas leveduras. Os experimentos foram divididos em três partes: 1a avaliar a ação tóxica do alumínio frente às leveduras industriais BG-1, CAT-1, Fleischmann e PE-2 na fermentação de mosto de caldo de cana (19% ART) com 130 ppm Al; 2a avaliar a ação tóxica do alumínio frente à levedura industrial CAT-1 e as colônias de leveduras C1, C5, e C6 isoladas de uma destilaria produtora de álcool combustível fermentando mosto de caldo de cana (19% ART) com 54 ppm Al com 5 reciclos de células e a 3a foi avaliar a ação tóxica do alumínio frente à levedura industrial CAT-1 e as colônias de leveduras C8, C10, e C11 isoladas de uma destilaria produtora de álcool combustível fermentando mosto de caldo de cana (19% ART) com 54 ppm Al com 5 reciclos de células. Os resultados mostram que no primeiro experimento, a ação tóxica do alumínio em mosto de caldo acarreta efeitos estressantes diferenciados dependendo da linhagem de levedura avaliada. As linhagens CAT-1 e BG-1 são as mais tolerantes ao alumínio, quando comparadas com a PE-2 e Fleischmann, sendo esta última a mais vulnerável em relação a todos os parâmetros estudados. No segundo experimento os resultados obtidos nos permitem concluir que nível tóxico de alumínio em mosto de caldo exerce uma ação diferenciada em relação às leveduras industriais. Inferindo que a CAT-1 foi a mais tolerante ao metal mesmo acumulando mais alumínio, o rendimento foi o maior e os teores de trealose também foram menores. No entanto, de uma forma geral se pode inferir que as leveduras C6 e CAT-1 são mais tolerantes ao alumínio do que a levedura C1 e C5. No terceiro ensaio, concluiu-se que a CAT-1 foi a mais tolerante ao metal Al comparada com as linhagens selvagens C8, C10 e C11, tendo como principal efeito na diminuição da viabilidade e aumento do tempo fermentativo. No geral a linhagem de levedura CAT- 1 apresentou melhor desempenho fermentativo frente a ação tóxica do alumínio. / This study aimed to assess the effect of aluminium on the alcoholic fermentation using different strains of industrial yeasts (CAT-1, BG-1, PE-2, Fleischmann and wild yeast colonies isolated from production of alcohol fuel called C1, C5 , C6, C8, C10 and C11) in different concentrations of aluminium and also examine the accumulation of metal in yeast during fermentation with reused of cells, similar to industrial process, for such parameters have been assessed as: production of ethanol, fermentation rate, formation of biomass, glycerol production, use of trehalose, fermentative efficiency and accumulation of Al by yeasts. The experiments were divided into three parts: 1st available the toxic action of the aluminum front of industrial yeasts BG-1, CAT-1, Fleischmann and PE-2 in the fermentation of grape juice from cane (19% TS) with 130 ppm Al. 2nd available the toxic action of the aluminium front of the yeast industrial CAT-1 and the colonies of yeast C1, C5 and C6 isolated from a distillery producing alcohol fuel molasses fermenting of sugar cane juice (19% TS) with 54 ppm Al with 5 recyclation of cells and the 3rd was to evaluate the toxic action of the aluminium front of the industrial CAT-1 yeast and yeast colonies of C8, C10 and C11 isolated from a distillery producing alcohol fuel molasses fermenting of sugar cane juice (19% TS) with 54 ppm Al with 5 recyclation of cell. The results showed that in the first experiment, the toxic action of aluminium in the broth must involve stressful effects depending on different strain of yeast evaluated. The strain CAT-1 and BG-1 are the most tolerant to aluminium, compared with PE-2 and Fleischmann, the latter being the most vulnerable regarding all parameters studied. In the second the results allow us to conclude that toxic levels of aluminum in the broth must exercise a differentiated action in relation to industrial yeast. Deducing that the CAT-1 was the most tolerant even the metal accumulated more aluminum, the yield was the highest levels and levels of trehalose were also lower. However, in general it can be inferred that the yeast C6 and CAT-1 are more tolerant to aluminum than the yeast C1 and C5. In the third test, it was concluded that the CAT-1 was the most tolerant to the metal Al compared with the wild strains C8, C10 and C11, with the main effect in reducing the viability and growth of fermentation time. Overall the strain of yeast CAT-1 showed better performance fermentation front of toxic action of aluminium.

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Philosophiae Doctor - PhD / The increasing evidence of chemicals of emerging concern (CECs) in water bodies is causing major concern around the world because of their toxicological effects upon humans and aquatic organisms. The release of wastewater to the aquatic environment is most likely to introduce some trace levels of organic contaminants, some of which may be toxic, carcinogenic, or endocrine disruptors, as well as, persistent in the environment. These compounds are often persistent but not regularly monitored because they are mostly still excluded from environmental legislation. Their fate and persistence in the environment are not well understood

This diploma thesis is focused on determination of bioavailable cadmium in natural waters. Thesis is devided to two parts-laboratory study in model solution and experiments in real surface water system. During the laboratory experiments the accumulation and release constants of cadmium by aquatic moss Fontinalis antipyretica were determined. In Morava river experiment this aquatic moss was used to determine bioavailable fraction of cadmium and the moss bag technique were compared with another methods for phytotoxic metals determination.

Constantly increasing consumption of drugs leads to the increase of the concentration of residues in various environmental compartments. For this reason the drug residues are nowadays classified as significant environmental contaminants. The drug residues enter the soil along with the application of sewage sludge either as a fertilizer or during fertilizing by animal excrements excreted after drug administration, eventually by direct contamination from treated grazing animals. The presence of these substances in soil has got negative impact on the sensitive soil ecosystem. The diploma thesis aims to evaluation of possible soil contamination with selected drugs through ecotoxicity tests. For this purpose sulfonamide chemotherapeutic agents, which are often used in veterinary medicine, were chosen, specifically sulfamethoxazole and sulfamethazin. Eartworms (Lumbricus) were selected as suitable test representative soil organism. In the experimantal part of this work the avoidance test according to ISO 17512-1 and modified bioaccumulation test according to OECD 317 methodology were performed. Bioaccumulation substances in oligochaetes, for which the artificial soil was prepared according to OECD 207 methodology, which was subsequently contaminated with above specified drugs. Although according to the results of determination of these substances there is no significant bioaccumulation in eartworms‘ tissue, these organisms are very responsive to the presence of contaminants in the soil environment. This is evident from the results of avoidance tests.

Arsenic transfers and toxicology are important topics of research and a public health concern because arsenicosis affects millions of people worldwide every year. One of the most significant sources of arsenic in the environment is industrial wastes, such as by-products of mining operation. In Yellowknife, Northwest Territories, Canada, there were two large gold mines—Giant Mine and Con Mine, along with dozens of small-scale mines. The combined by-product of emission from these roasters might have contributed to high concentrations of arsenic found in the city. This thesis presents the results of two related studies to address the environmental health concern: (1) to investigate the arsenic transfers and arsenic species accumulation in freshwater food webs near large legacy mining operations in Yellowknife, and (2) to assess the long-term health risk of inorganic arsenic exposure from the consumption of fish in Yellowknife among the general residents and the Yellowknives Dene First Nation. We found that inorganic arsenic is biominified in food webs (i.e. inorganic arsenic concentrations diminish at higher trophic positions relative to lower trophic positions). Higher-trophic organisms have low inorganic arsenic concentrations in tissue due to biotransformation of inorganic arsenic to non-toxic organic arsenobetaine, and effective elimination of arsenic from their tissue. The trophic positions of freshwater organisms can be used to predict the range of arsenic concentrations and its species composition, accounting for more than 80% of variance. Dietary study results show that the Yellowknives Dene First Nation consumed significantly more fish in their diets (adults: 19 g/day, children: 9 g/day) compared to the general residents of Yellowknife (adults: 9 g/day, children: 5 g/day). Our probabilistic risk assessments showed no significant long-term non-carcinogenic and carcinogenic health risks of inorganic arsenic exposure from fish consumption for the majority of Yellowknife residents, but elevated cancer risks among the adult heavy fish consumers in Yellowknife. However, our data suggested that the residents of Yellowknife were not exposed to higher cancer risks from inorganic exposure compared to the general population in Canada. Therefore, due to fish health benefits and the values associated with its consumption, fish should continue to be a major source of sustenance in Yellowknife.

Polyaromatic hydrocarbons (PAHs) are oil derived toxic and persistent pollutants prevalent across the oceans from pelagic waters to coral reefs. The Great Barrier Reef (GBR) in Australia and the Red Sea are important oligotrophic marine ecosystems susceptible to oil contamination. This Ph.D. dissertation aims to advance our understanding on PAH tolerance, accumulation dynamics and trophic transfer in oligotrophic ecosystems where those aspects remain poorly explored. In this dissertation, a new, highly-sensitive method combining stable carbon isotope labelling and cavity ring-down spectroscopy (CRDS) was developed to quantify PAH accumulation and applied in a series of ex situ food chain experiments with two representative PAHs, 13C-phenanthrene and 13C-pyrene. The experiments conducted with Acropora millepora – a common reef-building coral in the GBR, showed faster accumulation of both PAHs by dissolved uptake, although dietary exposure caused more consistent accumulation. Phenanthrene was not toxic to the coral photosystem II in either exposure mode but biomagnification increased with increasing food-chain complexity. In contrary, pyrene led to loss of symbionts accompanied by reduction in photosynthetic efficiency and coral bleaching, especially via dietary uptake. Also, microbial communities and food webs are relevant components of oligotrophic waters. We identified contrasting sensitivities among key autotrophic and heterotrophic microbial populations in the chronically oil exposed Red Sea to a mixture of 16 PAHs recognized as priority pollutants. The differential tolerance pointed towards localized selection for resistant strains in some populations. Some PAH toxicity thresholds approached ambient PAHs concentrations suggesting that any increase in pollution loads will hold consequences for these important microbial groups and their ecological functions.

L'objectif de cette étude est d'étudier le potentiel d'Opuntia ficus-indica (Ofi) en tant que biomoniteur dans un environnement contaminé par des dépôts atmosphériques enrichis en métaux lourds. Trois sites d'étude pollués ont été sélectionnés: industriel, minier et routier. Le phénomène de bioaccumulation a été validé en analysant la concentration en métaux lourds par SAA et ICP-MS dans plusieurs raquettes d'âge différent, dans les fruits et les racines. L'identification de l'origine du Pb a été étudiée à partir de la signature isotopique du Pb (TIMS) dans les raquettes, les racines et les sols, avec une caractérisation microscopique (MEB-EDX) des particules déposées à la surface des raquettes. Le taux de bioaccumulation du Pb suite à une exposition racinaire ou foliaire à des particules de fluorapatite synthétisées et enrichies en Pb à permis de préciser les voies de transfert vers la plante. Ainsi, la distribution particulaire ou dispersée du Pb dans les raquettes contaminées a été identifiée au moyen de cartographies MEB-EDX et µXRF. Les résultats obtenus montrent qu'Ofi est un bioaccumulateur du Pb, Cd et Cr. Les signatures isotopiques dans les raquettes révèlent la nature des diverses sources polluantes tout en donnant une indication sur l'évolution de la pollution atmosphérique au cours du temps. Le taux le plus élevé de Pb a été mesuré dans les raquettes contaminées à leur surface par de la fluorapatite. Les analyses microscopiques ont démontré pour les deux approches suivies l'intégration des particules déposées à la surface des raquettes au niveau de la cuticule, des trichomes et des stomates. Cette obsevation est cohérente avec la cartographie obtenue en µXRF. Notre étude démontre le potentiel de cette plante cosmopolite qu'est Ofi en tant que biomoniteur. / This study reports the potential of Opuntia ficus-indica (Ofi) as a biomonitor of atmospheric pollution in three heavily polluted sites, i.e., industrial, mining and road sites. The bioaccumulation phenomenon by Ofi was investigated by studying the heavy metal concentrations in different cladodes of various ages, roots and fruits, using AAS and ICP-MS. To identify the origin of Pb in cladodes, two types of methods were used: TIMS analysis which provided the lead isotopes ratios in cladodes, roots and soil samples, and SEM-EDX analysis at the cladode surface which provided the elemental distribution of Pb and airborne particles and a characterization of their chemical structure at the microscopic scale. A second study was also carried out by testing Pb bioaccumulation after foliar and roots exposure to synthesized fluorapatite particles enriched with Pb. SEM-EDS and µXRF analyses were used to follow the Pb concentration from the contaminated surface to the internal tissues. The results show that Ofi is indeed a bioaccumulator of Pb, Cd and Cr. The Pb isotopic signatures indicate that Ofi is a sensitive species to local aerial pollution and their successive cladodes obviously identify the evolution of air pollution with time. In addition, Ofi cladodes were found more contaminated with lead after direct foliar contamination. SEM-EDS measurements underlined in the two studies the retention of deposited particles on specific zones of the cladode surface (cuticle, trichome and stomata), which were also identified by µXRF cartography. These results represent the first demonstration of the potential of using Ofi, a cosmopolitan plant, as a biomonitor.

Stormwater runoff may contain high levels of pollutants and is regulated by the Federal National Pollution Discharge Elimination System (NPDES). Stormwater bioretention (BR) systems are often used to satisfy these regulations. BR systems collect accumulated runoff that leaches into groundwater. A greenhouse study evaluated nutrient and metal removal among plant species that are typically found growing in BR systems. A field demonstration study assessed citric acid enhanced metal bioaccumulation potential under typical BR system conditions. The greenhouse experiment examined pollutant retention, and bioaccumulation potential for six plant species undergoing three hydraulic and pollutant loads. Results verified there was 98% recovery of total phosphorous over the study period. Biomass increased with higher hydraulic and pollutant loads for all species. Phragmites australis, Carex praegracilis, and Carex microptera took up significantly more total phosphorous and nitrogen mass into shoots than Typha latifolia, Scirpus valid us, and Scirpus acutus. This study also found that 89% of applied metals were removed within the top 27 em of soil in all treatments. Similar results were found regarding copper, lead, and zinc concentrations and bioaccumulation. Carex praegracilis, and Carex microptera exhibited higher metal distribution in plant tissue and exfiltrate, and lower distribution in the soil media than the other species. This indicated species differences in biological and chemical processes taking place within the simulated BRsystems. The field experiment investigated citric acid enhanced metal bioaccumulation potential among three different plant species under representative BR conditions. Citric acid significantly increased metal concentrations in the soil pore water for the planted treatments, but this did not result in increased metal uptake into plant tissue. However, notable differences were found among species, where Carex microptera accumulated more AI, Cr, Cu, and Fe in the above ground tissue than Helianthus maximiliani and Typha /atifolia (except for Cu in Helianthus). These results provide greater insight into the biological and chemical process that affect transport, uptake and translocation of nutrients and metals, and confirm the importance of species selection in BR systems to optimize nutrient and metal retention and recovery from stormwater runoff to minimize subsequent groundwater pollutant loading.

Thesis (M. Eng. in Ocean Engineering)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and the Woods Hole Oceanographic Institution), 1999. / Includes bibliographical references (leaves 97-103). / by Rachel H. Levine. / M.Eng.in Ocean Engineering