Orientador: Lucia Regina Durrant / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-03T18:02:39Z (GMT). No. of bitstreams: 1 CuadrosOrellana_Sara_D.pdf: 8786475 bytes, checksum: 37002d082a1fea19d88bc66b7dced99e (MD5) Previous issue date: 2003 / Resumo: O metabolismo de compostos aromáticos depende de fatores físico-químicos como temperatura, pH e salinidade, e é bem conhecido e caracterizado em microrganismos mesófilos e em condições ambientais moderadas. No entanto, pouco se conhece sobre o metabolismo desses compostos em ambientes hipersalinos. este trabalho, cinco ambientes hipersalinos foram analisados quanto à presença de arqueas halofílicas capazes de metabolizar compostos aromáticos: Salar de Uyuni (Bolívia), salinas de Cahuil (Chile), salinas de Cabo Rojo (Porto Rico), sabkhas da região do Golfo Pérsico (Arábia Saudita) e Mar Morto (Israel e Jordânia). A estratégia empregada para o enriquecimento e isolamento de arqueas halofílicas capazes de crescer em presença de compostos aromáticos foi bem sucedida. Foram isoladas 12 linhagens capazes de crescer em presença de 1 ,2--benzoantraceno (2 mM) e 44 linhagens capazes de crescer em presença de ácido p-hidroxibenzóico (10 mM) como única fonte de carbono e energia. O isolado MM 17, proveniente de uma amostra de água do Mar Morto, apresentou o melhor resultado de crescimento e foi capaz de degradar completamente os ácidos benzóico (10 mM) e p-hidroxibenzóico (10 mM) após 200 h de cultivo. As análises bioquímica e genética dos isolados, juntamente com a análise dos perfis de lipídeos polares, indicaram que as linhagens estudadas pertencem a pelo menos dois gêneros: Haloferax e Halobacterium. Foi determinada a secreção de uma proteína de alto peso molecular por Haloferax volcanii em resposta à presença de 2 mM 1 ,2-benzoantraceno no meio de cultivo. Com o objetivo de estudar o mecanismo de secreção protéica em haloarqueas, o qual não é completamente entendido_ foram realizadas a clonagem molecular dos genes secD e secY de Haloferax volcanii, a expressão heteróloga em Escherichia coli e a purificação dos produtos gênicos, além de uma tentativa preliminar de obtenção de anticorpos policlonais através da imunização de coelhos / Abstract: The metabolism of aromatic compounds depends on physical-chemical factors such as temperature, pH and salinity, and is well known and characterized in mesophilic microorganisms under mild environmental conditions. Little is known, however, about the metabolism of these compounds in highly saline environments. Here, five hypersaline sites were tested for the presence of halophilic archaea able to metabolize aromatic compounds: the Uyuni Salt Marsh (Bolivia), the crystallizer ponds in Cahuil (Chile), the crystallizer ponds in Cabo Rojo (Puerto Rico), the sabkhas in the Persian Gulf (Saudi Arabia) and the Dead Sea (Israel and Jordan). The strategy used for the enrichment and isolation of halophilic archaea able to grow in aromatic compounds was successful. Twelve strains able to grow in 1,2-benzoantracene (2 mM) and 44 strains able to grow in p-hydroxybenzoic acid (10 mM) as the sole carbon and energy source were isolated. Strain MM17, isolated from a Dead Sea water sample, showed the best growth and was able to degrade benzoic (10 mM) and p-hydroxybenzoic (10 mM) acids afier 200 h of cultivation. Biochemical and genetic analyses of the isolates, together with the analysis of polar lipid profiles, indicate that the strains belong to at least two different genera: Haloferax and Halobacterium. The secretion of a high molecular weight protein by Haloferax volcanii following cultivation in 2 mM 1,2-benzoantracene was observed. To study the mechanism of protein secretion in halophilic archaea, a process that is not completely understood, preliminary studies were conducted, which included cloning of secO and secY genes of Haloferax volcanii, their heterologous expression in Escherichia coli and the purification of the gene products. In addition, a preliminary attempt to obtain polyclonal antibodies through rabbit immunization was made / Doutorado / Doutor em Ciência de Alimentos

Orientadores: Telma Teixeira Franco, Lucia Regina Durrant / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-03T21:02:47Z (GMT). No. of bitstreams: 1 Tomaz_RoseMarryAraujoGondim_D.pdf: 4644251 bytes, checksum: 70dfbe58b4071cd1f724a85ce480e652 (MD5) Previous issue date: 2003 / Resumo: Inicialmente, foi desenvolvido experimento em casa-de-vegetação com dois tipos de solo, arenoso e argiloso, com o objetivo de avaliar o efeito dos herbicidas diuron e pyrithiobacsodium-sodium na microbiota do solo. Doses de diuron e pyrithiobac-sodium de O, 1, 2, 4 e 8 vezes a dose recomendada para o campo foram aplicadas sobre plantas de algodão, cv IAC 23. Amostras de solos foram coletadas periodicamente para levantamento das populações de fungos, bactérias e actinomicetos, determinação do pH e seleção de fungos no solo com a mais alta dose dos herbicidas. Houve diferença entre a biota dos solos para ambos os herbicidas. A população de fungos e bactérias diminuiu com o acréscimo das doses aplicadas a de actinomicetos aumentou para o solo argiloso e reduziu para o arenoso quando se utilizou o diuron. Para o pyrithiobac-sodium ocorreu aumento da população de fungos, redução do número de bactérias e, em relação aos actinomicetos, a população diminuiu no solo arenoso com o aumento das doses. No solo argiloso, apenas na dose recomendada apresentou crescimento de actinomicetos, havendo redução com as demais doses. Os 106 fungos isolados foram utilizados em experimentos para seleção delinhagens resistentes a concentrações elevadas dos herbicidas, utilizando meio sólido suplementado com concentrações crescentes dos herbicidas especificados. Em paralelo, realizou-se a seleção com 24 linhagens de fungos basidiomicetos utilizando, também, meio sólido com elevadas doses dos herbicidas como fonte de carbono. No total, trezefungos foram selecionados (Pleurotus sp (BCCB 507), Pleurotus sp (CCB 068), Pleurotus sp 016, Agarucu.s campestris, Phanerochaete chrysosportum ATCC 24725 e os isolados de solo DP24e, DP240, DRPO2n, DRP02e, SPI6a, SRPI7g, SRP17c e SRP20e). Esses fungos foram incubados em meio liquido de minerais por três dias. Após os três dias, adicionouse 25 pg.mL-l de diuron ou 10 pg.mL-l de pyrithiobac-sodium ao frasco de cultura e incubou-se por 14 dias. As atividades ligninoliticas e porcentagem de degradação foram analisadas, quando se utilizou diuron como fonte de carbono, as linhagens Pleurotus sp (CCB 068) (85,63%), Pleurotus sp (BCCB 507) (64,30%), Pleurotus sp 016 (62,06%) e os isolados de solo SRP17c (71,08%), SRP17g (69,42%), e SRP20e (66,38%) apresentaram as mais altas porcentagens de degradação. Manganês-peroxidase foi a enzima predominante produzida por todas as linhagens. Quando se utilizou pyrithiobac-sodium, somente três linhagens foram capazes de degradá-lo: Pleurotus sp (CCB 068) (61,35%), Agaricus Campestris (37,86%) e Pleurotus sp (BCCB 507) (16,10%). A MnP foi também a enzima predominante. Considerando ambos os herbicidas, a linhagem Pleurotus sp (CCB 068) foi a melhor de todas as testadas. É importante mencionar que as mais altas atividades enzimáticas foram produzidas por essa linhagem, independentemente do herbicida. Com os resultados de degradação e de atividade enzimática mais expressivos, foram selecionadas quatro linhagens: Pleurotus sp (BCCB 507), SRP17 c, Pleurotus sp (CCB 068) e Ag. Campestris; nas três primeiras se utilizou diuron como fonte de carbono; e nas duas últimas, pyrithiobac-sodium. Esses fungos cresceram em concentrações diferentes de diuron (25 pg.mL-l e 35 pg.mL-l) e pyrithiobac-sodium (10 pg.mL-l 20 pg.mL-l), sendo incubados por 30 dias, determinando-se também a porcentagem de degradação. Quando se utilizou diuron, a mais alta porcentagem de degradação foi obtida no sobrenadante da linhagem SRP17c (35 pg.mL-l) (84,74%), seguida da linhagem SRP17c (25 pg.mL-l) (73,46%) e Pleurotus sp (CCB 068) (35 pg.mL-l) (55,11%). Para o pyrithiobac-sodium, a melhor porcentagem de degradação foi obtida no sobrenadante da linhagem Pleurotus sp (CCB 068) (20 pg.mL-l) (94,61%), seguido da linhagem Pleurotus sp (CCB 068)(10 pg.mL-l) (86,42%) e Ag. Campestris (10 pg.mL-l) (53,36%). De acordo com a identificação realizada para o fungo isolado de solo SRP 17 c, sugere-se que pertença ao gênero Rhizopus / Abstract: Pyrithiobac-sodium is a post-emergence herbicide for early application, registered for broadIeaves control in cotton crops. Diuron is a phenylurea used for weed control on non-crop areas and selectively on crops such as cotton, sugarcane, citrus and pineapple. At present, this herbicide is one of the IDOst used in Brazil. Experiments were carried out in green-house, in order to evaluate the effect of these two compounds on the soil biota. Such compounds were applied in O, 2, 4 and 8 times above the recommended rate, and cotton IAC 23 was used. Cotton was planted in sandy and c1ay soils. Soil samples were collected periodically, until 70 and 135 days after application for pyrithiobac-sodium and diuron, respectively. Counting of fungi, actinomycete and bacteria population was realized, and also sail pH variation and several fungi strains selective1y isolated from sail samples previous1y treated with the higher concentration of diuron and pyrithiobacsodium. The biota showed be different regarding the two soil types. To the sandy soil, the increase of pyrithiobac-sodium rate reduced the actinomycete population. To c1ay soil, on1y the recommended rate increased the number of actinomycete, with reduction for higher rates. In both soils the fungi population increased with the increase of the herbicide rate, occurring the opposite for the bacteria population. For the both of soils treated with diuron, the fungi and bacteria population reduced with the increase of the herbicide rate, and actinomycete population increased in the clay soil and was reduced in the sandy soil. The pH increased gradually during the time in both of the soils studied. A total of 106 strains were isolated, of which 8 were selected for furilier evaluation of potential pesticides degradation on the highest levels of these two compounds: DP24e, DP240, DRPO2n, DRP02e SPI6a, SRP 17c, SRP17g and SRP20e. Twenty-four ligninolytic white rot fungi were also used in the preliminary screen. A solid medium containing 1x, 10x or 100x of the pesticides dos ages indicated for fielding application was used as carbon sources. Five strains were selected: Pleurotus sp BCCB 507, Pleurotus sp CCB 068, Pleurotus sp. 016, Agaricus campestris, Phanerochaete chrysosporium ATCC 24725. These fungi were groWD in liquid medium containing minerais and yeast extract for three days when 25 Jµg mL-1of diuron or 10 Jµg mL-1 of pyrithiobac-sodium were added in the culture flasks, and the cultivators were carried out for up to 14 days. Samples were collected and the supernatants were used for the determination of ligninolytic activities (by spectrophotometric assays) and degradation (by HPLC). When diuron was used, highest degradation were observed by the strains Pleurotus sp CCB 068 (85,63%), Pleurotus sp BCCB 507 (64,30%), Pleurotus sp.016 (62,06%), and the soil-isolated SRP17c (71,08%), SRP17g (69,42%) and SRP20e (66,38%). MnP was the predominant enzyme produced by alI strains. When Pyrithibac-sodium was used for as carbon source in the medium on1y three strains were able to degrade it: Pleurotus. sp. CCB 068 (61,35%),Ag. campestris (37,86%) and Pleurotus sp BCCB 507 (16,105%); MnP was a1so the predominant ligninolytic enzyme produced. A new selection of the best strains was carried out based on the levels of herbicides degradation, and also regarding the ligninolytic activities produced by the fungi. The four strains selected were cultivated for 3,6,9, 12, 15,20,25 and 30 days in the diuron (25 Jµg mL-1 e 35 Jµg roL-I) or pyrithiobac-sodium (10 Jµg mL-1 20 Jµg mL-1). Herbicides degradation measured by HPLC, varied with each strain. Highest degradation of diuron (84,74%) was detected by the strain SRP17c 35 J1g mL-1 followed by strain SRP17c 25 Jµg mL-1 (73,46%) and Pleurotus sp (CCB 068) 35 Jµg mL-1 (55,11%). The greatest degradation ofpiIythiobac-sodium (94,61%) was observed with Pleurotus sp (CCB 068) 20 Jµg mL-1 followed by strain Pleurotus sp (CCB 068) 10 Jµg mL-1(86,42%) and also for Ag. Campestris 10 Jµg roL-1 (53,36%). The strain identification SRP17c suggests that this strain belongs to the Rhizopus Class / Doutorado / Desenvolvimento de Processos Químicos / Doutor em Engenharia Química

Les mycotoxines telles que la fumonisine B1 (FB1) produites par les champignons du genre Fusarium sont particulièrement préoccupantes pour la filière maïsicole. L’ensilage de maïs est un processus de fermentation naturel susceptible de favoriser l’évolution des teneurs en FB1. La maîtrise du risque de contamination par la FB1 et la recherche de moyens permettant la décontamination des ensilages est donc nécessaire. L’objectif de ce travail est de caractériser le devenir de la FB1 dans les ensilages de maïs grain et de mettre en évidence l’existence d’agents microbiens capables de dégrader cette toxine. Pour cela, des mini-silos contenant du maïs grain naturellement contaminé en FB1 provenant de différents parcelles et issus des deux années de récolte ont été préparés. La stratégie analytique basée sur le dosage de la FB1 libre et la FB1 complexée par HPLC-MS/MS a révélé une diminution significative de la teneur en FB1 totale qui ne peut être attribuée à un mécanisme de complexation et résulte d’un mécanisme de dégradation. La recherche du microbiote associé à la dégradation de la FB1 a été réalisée par deux approches complémentaires : Une analyse métagénomique combinant l’extraction sélective de l’ADN microbien et le séquençage haut débit «shotgun» afin de comparer la diversité taxonomique et fonctionnelle d’un ensilage dégradant la FB1 et d’un ensilage moins dégradant. En parallèle, un criblage de microorganismes cultivables capables de métaboliser la FB1 a été conduit et a permis de confirmer les résultats de l’analyse globale. Ce travail apporte une première image du microbiote potentiellement associé à la dégradation de la FB1, ainsi que des activités microbiennes responsables. / Fungi of the genus Fusarium are one of the major contaminants of maize that can produce mycotoxins, such as the fumonisin B1 (FB1). Maize silage which is based on the fermentation of whole crop plant or grains is considered the main source of monogastrics and cattle feeding in Europe. The ensiling process could favor changes in FB1 content; however this has scarcely been documented. This led to questioning regarding the possibility of managing the microbiota during ensiling in order to reduce the level of mycotoxins exposure and improve feed quality. The aim of this work is to study the fate of FB1 during ensiling process of high moisture maize grain and to identify an endemic microbiota capable of degrading FB1. Laboratory scale silages were prepared with naturally contaminated FB1 grains from two cropping years. An analytical procedure allowed assessing both free and matrix associated FB1 forms and showed a significant decrease in total FB1 content that are not linked to the presence of bound FB1. Additionally, our data showed that the FB1 content decrease was mainly due to a degradation process. Identification of a potential microbiota responsible for FB1 degradation was conducted. A metagenomics approach combining a selective microbial DNA extraction and high-throughput shotgun sequencing showed microbial specific patterns between FB1 degrading and weakly degrading silage. These results were also supported by the isolation of microbial strains able to metabolize FB1. Ultimately, this work evidenced a microbiota associated to FB1 degradation and the functional diversity involved in this activity. Bacteria and yeasts have been obtained for further studies on degradation activities and their usage as silage starter.

Pharmaceutical compounds comprise a wide range of substances that are consumed in large quantities by modern societies and are generally released into local sewer networks through excretion. This research aimed to identify the factors affecting the removal efficiencies of these compounds in biological wastewater treatment plants (WWTPs) under different environmental conditions. Of the pharmaceutical compounds selected for this study, the highest influent concentrations measured in municipal wastewater treatment plants (MWWTPs) were for paracetamol, naproxen and bezafibrate (> 1 μg/L), followed by carbamazepine, atenolol, lidocaine, sulfamethoxazole and NACS (<1 μg/L). In hospital wastewater treatment plants (HWWTPs), the highest concentrations measured were for paracetamol and caffeine (> 10 μg/L), followed by ciprofloxacin and NACS (1–6 μg/L), and finally bezafibrate, carbamazepine, atenolol, lidocaine, clarithromycin and sulfamethoxazole (< 1μg/L). Antibiotic drugs were detected in HWWTPs, but rarely detected in MWWTPs. In general, the hospital wastewaters contained relatively higher levels of pharmaceuticals than municipal wastewaters. The removal efficiencies of the pharmaceutical compounds ranged widely. This was found to be related to characteristics and operational parameters of the individual WWTPs. The MWWTPs that utilized long aeration and biomass retention times (HRT,SRT), as evidenced by the occurrence of complete nitrification, were more efficient at removing paracetamol, naproxen, bezafibrate and atenolol, than the non-nitrifying plants with relatively shorter HRT and SRT. HWWTPs that operated under elevated ambient temperatures (> 26°C) achieved higher removal efficiencies (90%) for several compounds, including paracetamol, caffeine, sulfamethoxazole, ciprofloxacin, clarithromycin, NACS, atenolol, carbamazepine and lidocaine. In addition to the elevated ambient temperatures, elevated HRT and SRT and less dilution can lead to increased active biomass and can result in higher removal rates for the pharmaceutical compounds. Overall, the removal efficiencies of pharmaceuticals in WWTPs have been correlated to the type of treatment plant, the plants’ operational parameters (HRT, SRT), the climatic conditions (temperature and dilution effect of rainfall) and characteristics of the micropollutants (type and concentration). Aerobic and anaerobic batch biodegradation experiments were conducted to observe the removal of paracetamol, naproxen, ibuprofen and sulfamethoxazole at various SRTs. The biodegradation rates varied widely ranging from poor, to moderate, to high, depending on the SRT. Paracetamol was highly biodegradable under both aerobic and anaerobic conditions. Sulfamethoxazole was poorly biodegradable under aerobic conditions but highly biodegradable under anaerobic conditions. Relatively slow biodegradation rates were observed for ibuprofen and naproxen under both conditions; longer microbial adaptation periods for these two compounds were probably required. The most important factor affecting the removal of the compounds was the SRT. Therefore, the conclusion was drawn that combining anaerobic and aerobic systems with longer SRT and HRT could bring about significant reductions in the emissions of these contaminants into the environment via WWTPs; this is also a cost-effective option.

Abstract This study concentrates on developing and tuning various oil analysis methods to meet the requirements of modern industry and environmental analytics. Oil analysis methods form a vital part of techniques used to monitor the condition of machines and may help to improve the overall equipment effectiveness value of a factory in a significant manner. Worm gears are used in various production machines, and their breakdowns may cause significant production losses. Wearing of these gears is relatively difficult to monitor with vibration analysis. Analysis of two indicator metals, copper and iron, may reveal wearing phenomena of worm gears effectively, and savings can be significant. Effective wear metal analysis requires good tools. ICP-OES with kerosene dilution is widely used in wear metal analysis, but purchasing and using of ICP-OES is expensive. A cheaper FAAS technique with similar pre-treatment of oil samples was tested and it proved to be useful especially in analyzing small amounts of samples. The accuracy of FAAS was sufficient for quantitative work in machine diagnostics and waste oil characterization. Solid debris analyses are useful in oil contamination control as well as in detection of wearing mechanisms. Membrane filtration, optical microscopy, SEM and automatic particle counting were applied in analysis of rolling and gear oils. Particle counting is an effective way to detect oil contamination, but in the studied cases even larger particles than those detected in normal ISO classes would be informative. However, membrane filtration and optical microscopy may reveal the wearing machine element exactly. Additives provide oils with desired properties thus they should be monitored intensively. A FTIR method for quantitative analysis of fatty alcohols and fatty acid esters in machinery oils was developed during this work. It has already been used successfully in quantitative and qualitative analysis of machinery oil samples. Various kinds of oils may be spilled into the soil during use and in accident situations, and they can migrate to groundwater layers. Biodegradation of oils can remove them from the soil or water completely or at least diminish the amount of harmful substances. An automatic, respirometric BOD OxiTop method was used to evaluate the biodegradability of various oils in water and soil media. The biodegradation of certain bio and mineral hydraulic oils was evaluated in groundwater, where bio oils usually biodegraded more effectively than mineral oils. The use of oils in machines weakened especially the biodegradability of bio oils. Biodegradability of bio oils was also studied in standard conditions of OECD 301 F and bio oils usually biodegraded moderately good in these conditions. The biodegradation of forestry chain oils and wood preservative oils was evaluated in forest soils. Linseed oil biodegraded moderately, but certain experimental wood preservatives biodegraded more effectively. Widely used creosote oil biodegraded in a lesser degree. Rapeseed oil-based chain oils biodegraded more effectively than corresponding tall oil.

This thesis describes dip tank field trials and laboratory investigations on the acaricide Amitraz. Amitraz is a triazapenta- diene compound which is relatively unstable in fouled dip washes. The field trials were conducted on the farm Sea View according to the "Total Replacement Method" and on the farm Sea Ways according to the "Lime Stabilization Method" of dipping. The results of these trials showed that Amitraz was stable in clean dip washes, and under conditions of high pH resulting from the addition of slaked lime to the dip wash. Using mixed bacterial populations optimum conditions for degradation of Amitraz in the laboratory were determined. Bacterial cultures degraded Amitraz most efficiently in media supplemented with yeast extract or with a high content of sterile cattle faeces. Amitraz concentrations were determined by gas chromatography. A culture. efficient at degrading Amitraz was enriched from a dip tank sludge inoculum. From this culture ten bacterial isolates were identified; nine of these were of the genus Pseudomonas and one was an Achromobacter sp. Experiments with both mixed and pure cultures demonstrated that bacterial degradation of Amitraz was by the process of co-metabolism. The existence of four degradation products was shown using thin layer chromatography. Tentative identification of two of the products was made.

No description available.

Low-grade coal, a poor source of energy, has long been regarded as waste material by the coal mining industry. Biological degradation of this coal material by ligninolytic fungal strains presents a viable strategy towards eliminating this unusable fossil fuel. To this end, a novel and patented bioprocess termed Fungcoal was developed. Fungcoal is a biological process utilised in the in situ treatment of waste coal and is based on the mutualistic relationship between the fungus Neosartorya fischeri and the graminaceous species Cynodon dactylon. The process facilitates the rapid conversion of waste coal into soil-like material that stimulates establishment of vegetation for eventual coal dump rehabilitation. While a number of in vitro studies have identified various fungal strains as efficient coal degraders, the mechanisms involved in the Fungcoal-stimulated degradation process have not been fully elucidated. Furthermore, implementation of Fungcoal at both pilot and commercial scale has not been achieved. Thus the objective of this work was to investigate Fungcoal as a bioprocess via examining the role of coal degrading fungi (CDF) and grasses as biocatalysts in coal biodegradation and for the self-cladding of waste coal dumps. Initially, waste coal degradation by N. fischeri, strain ECCN 84, was investigated, specifically focusing on the mechanisms underpinning the process. In vitro studies showed the addition of waste coal induced active fungal colonisation resulting in increased fungal biomass. Increased extracellular laccase (LAC) activity, occuring concomitantly with an increase in hyphal peroxisome proliferation, was also observed in the coal supplied fungal cultures. Analysis of the colonised waste coal revealed a time dependent reduction in the percentage weight of elemental carbon coupled with an increase in elemental oxygen. The results supported metabolism and degradation of waste coal by N. fischeri strain ECCN 84 and involvement of fungal extracellular laccase. The contribution of C. dactylon, a C4 grass species to in situ biodegradation of waste coal in the presence of coal degrading and mycorrhizal fungi (MF) was also investigated. Enhanced degradation of the waste coal into a humic soil-like material was observed within the rhizosphere. Analysis of the resultant substrate revealed an increased concentration of highly oxidised humic-like substances (HS). Fungi remained viable in the rhizosphere up to 47 weeks post-inoculation and cultivation of C. dactylon, indicating the resultant humic substance-rich rhizosphere provided an environment conducive for microbial proliferation and activity. Furthermore, humic substance enrichment of waste coal substrates supported germination and seedling emergence of several agronomic species including Zea mays (corn), Phaseolus vulgaris (bean), Pisum sativum (pea), and Spinacia oleracea (spinach). Use of various cladding materials to support coal biodegradation, by fungus-grass mutualism and rehabilitation of waste dumps was evaluated at commercial scale. While substantial physico-chemical changes were not evident in the absence of cladding or where waste coal was used as cladding material, successful establishment of grass cover and diversity was achieved within three hydrological cycles on dumps cladded with weathered coal. Work presented in this thesis successfully demonstrates the degradation of waste coal by N. fischeri. The biodegradation process included enhanced extracellular LAC activity coupled with increased 3 waste coal oxidation. Increased HS concentration of waste coal substrate supported germination and early seedling establishment of several agronomic species. At commercial scale a co-substrate in the form of carbon-rich weathered coal was essential to support fungus-grass mutualism and Fungcoal-induced rehabilitation. These findings support the developed Fungcoal concept and the underpinning rationale that the phyto-biodegradation of waste coal indeed depends on the mutualistic interactions between grass root exudates and the ligninolytic and mycorrhizal fungi. Taken together, these findings provide practical evidence of the contribution of fungi and grasses as mutualists in the biodegradation of waste coal and sustainable rehabilitation of waste coal dumps

Vermicomposting is an eco-friendly waste management strategy. Its successful performance necessitate that key functioning parameters like earthworm stocking density, nutrient enrichment be established for each target waste/waste mixture. One main target waste mixture in South Africa, and in the University of Fort Hare in particular is waste paper mixed with cow dung and rock phosphate (RP) for phosphorus (P) enrichment. This study was carried out to address the following specific objectives, to determine (i) the effect of Eisenia fetida stocking density on the bioconversion of cow dung waste paper mixtures enriched with rock phosphate, (ii) an optimum application rate of low grade South African Rock Phosphate and time required for efficient vermicomposting of cow dung-waste paper mixtures, and (iii) to determine if the phosphorus in RP is responsible for improved biodegradation during the vermicomposting of cow dung-waste paper mixtures. Results of this study revealed that bioconversion of cow dung waste paper mixtures enriched with RP was highly dependent on E. fetida stocking density and time. The stocking density of 12.5 g-worms kg-1 feedstock of the mixtures resulted in highest earthworm growth rate and humification of the waste mixture as reflected by a C: N ratio of < 12, polymerization index (PI) or humic acid/fulvic acid ratio of > 1.9, and a humification index of >13 for the cow dung waste paper mixtures. A germination test carried out also revealed that the resultant vermicompost had no inhibitory effect on the germination of tomato, carrot, and radish. Extractable P increased with stocking density up to 22.5 g-worm kg-1 feedstock, suggesting that for maximum P release from RP enriched wastes, a high stocking density should be considered. Informed by an earlier study which demonstrated that RP improved vermidegration, a follow up study was done to determine the optimum amount of rock phosphate necessary for efficient vermidegradation of cow dung waste paper mixtures while ensuring a phosphorus rich vermicompost. The results showed that addition of RP at rates ≤ 1% P as RP efficiently enhanced the bioconversion of cow dung waste paper mixtures as reflected by low C: N ratio, high polymerization index (PI), HI and HR used as maturity indicators for matured compost. Final vermicompost products obtained at minimum amounts of RP application rates resulted highly humified vermicompost with finer morphological structure, with no inhibitory effect on the germination of tomato, carrot, and radish similar to the ones obtained at higher RP rates. The findings suggest that 1%P as RP application rate is optimum for efficient vermidegradation of cow dung waste paper mixtures. Since P or Ca happen to be the most prevalent elements in most rock phosphate used for compost enrichment, a study was carried out to determine if P or Ca in RP is predominantly responsible for the improved biodegradation of cow-dung waste paper mixture observed during vermicomposting. Phosphorus sources in form of triple superphosphate (TSP), phosphoric acid (PHA) and Ca in form of calcium chloride (CaCl2) salt were compared with rock phosphate. The results from the study indicated that TSP, a water soluble P source, resulted in greater and faster degradation of the waste mixtures than RP while the Ca source had the least effect. With TSP incorporation the compost maturity C: N ratio of 12 was reached within 28 days while RP, PHA and CaCl2 needed 42, 56 and more than 56 days, respectively. The results indicated that P was largely responsible for the enhanced bioconversion of the waste mixtures. This appeared linked to the effect of P to stimulate microbial growth as reflected by higher microbial biomass carbon levels where water soluble P sources were applied. The C: N ratios of the final vermicomposts at day 56 were 10, 11.5, 13, 14, and 23 for TSP, RP,PHA, Control (No P added) and CaCl2 treatments, respectively. Although TSP gave superior superior performance, RP may still be the preferred additive in the vermicomposting of cow dung waste paper mixtures as it is cheaper and produces mature compost in a shorter period of 8 weeks. Generally, the results of this study have shown that the vemidegradation of cow dung waste paper mixtures can be optimized through adoption of an E. fetida stocking density of 12.5g- worm kg-1 and an RP incorporation rate of 1% P as RP. However, higher rates of RPincorporation may be adopted where final vermicomposts with higher P fertilizer value are desired. Phosphorus appears to be the RP constituent responsible for its ability to enhance the vermidegradation of cow dung waste paper mixtures. Future studies should explore the effectiveness of other P-bearing minerals for their effectiveness in enhancing vemidegradation.

No description available.