Extraction of bitumen from Alberta oil sands produces 2 to 4 barrels of aqueous tailings per barrel of crude oil. Oil sands process water (OSPW) contains naphthenic acids (NAs), a complex mixture of carboxylic acids of the form CnH2n+ZOx that are persistent and toxic to aquatic organisms. Previous studies have demonstrated that aerobic biodegradation reduces NA concentrations and OSPW toxicity; however, treatment times are long. The objective of this study was to evaluate the feasibility of an immobilized soil bioreactor (ISBR) for treatment of NAs in OSPW and to determine the role of ammonium and ammonium oxidizing bacteria (AOB) in NA removal. ISBRs have been used to successfully remediate water contaminated with pollutants such as pentachlorophenol and petroleum hydrocarbons. A system of two ISBRs was operated continuously for over 2 years with OSPW as the sole source of carbon. Removal levels of 30-40% were consistently achieved at a residence time of 7 days, a significant improvement compared to half-lives of 44 to 240 days reported in the literature. However, similar to biodegradation experiments in the literature, a significant portion (~60%) of the NAs was not degraded. The role of AOB in NA removal was investigated by decreasing ammonium concentration and inhibiting AOB activity with allylthiourea, neither of which significantly affected removal, indicating that AOB did not enhance NA removal. Furthermore, high AOB populations actually inhibited the removal of a simple NA surrogate. Therefore, a moderate ammonium concentration of 0.3 g/L is recommended. NA degradation occurred with nitrate as the sole nitrogen source, however, removal levels were lower than those achieved with ammonium. Exploratory studies involving ozonation or biostimulation were conducted with the aim of increasing NA removal. Ozonation decreased NA concentration by 94% and total organic carbon (TOC) by 6%. Subsequent ISBR treatment removed ~30% of the remaining TOC. Addition of a NA surrogate increased heterotrophic NA-degrading populations due to the increase in available carbon, resulting in a significant increase in NA removal levels. However, use of a surrogate may result in a population that is only adapted to degradation of the NA surrogate. / Thesis (Master, Chemical Engineering) -- Queen's University, 2013-06-20 14:53:47.498

The environmental fate of polycyclic aromatic hydrocarbons (PAH) is a significant issue, raising interest in bioremediation. However, the physio-chemical characteristics of PAHs and the physical, chemical, and biological properties of soils can drastically influence in the degradation. Moreover, PAHs are toxic and carcinogenic for humans and their rapid degradation is of great importance. The process of degradation of pollutants can be enhanced by manipulating abiotic factors. The effect of soil pH on degradation of PAHs with a view to manipulating soil pH to enhance the bioremediation of PAH’s was studied. The degradation rate of key model PAHs (Phenanthrene, Anthracene, Fluoranthene, and Pyrene) was monitored in J Arthur Brower’s topsoil modified to a range of pH between pH 4.0 and pH 9.0 at half pH intervals. Photo-catalytic oxidation of PAHs in the presence of a catalyst (TiO2) under UV light at two different wavelengths was studied. The degradation of PAHs during photo-catalytic oxidation was carried out at varying soil pH, whilst the degradation rate of each individual PAH was monitored using HPLC. It was observed that pH 6.5 was most suitable for the photo-degradation of all the PAHs, whilst in general acidic soil had greater photo-degradation rates than alkaline soil pH. Photo-degradation of PAHs at 375 nm exhibited greater degradation rates compared to 254 nm. Phenanthrene at both the wavelengths had greater degradation rate and pyrene has lower degradation rate of the four PAHs. Pure microbial cultures were isolated from road-side soil by shaken enrichment culture and characterized for their ability to grow on PAHs. Bacterial PAH degraders, isolated via enrichment were identified biochemically and by molecular techniques using PCR amplification and sequencing of 16S rDNA. Sequences were analyzed using BLAST (NCBI) and their percentage identity to known bacterial rDNA sequences in the GeneBank database (NCBI) was compared. The 6 bacterial strains were identified as Pseudomonas putida, Achromobacter xylosoxidans, Microbacterium sp., Alpha proteobacterium, Brevundimonas sp., Bradyrhizobium sp. Similarly, fungal PAH degraders were identified microscopically and with molecular techniques using PCR amplification and sequencing of 18S rDNA and identified as Aspergillus niger and Penicillium freii. Biodegradation of four PAHs with two and four aromatic rings were studied in soil with inoculation of the six identified bacteria and two identified fungi over a range of pH. It was observed that pH 7.5 was most suitable for the degradation of all the PAHs maintained in the dark. A degradation of 50% was observed in soil pH 7.5 within first three days which was a seventh of the time taken at pH 5.0 and pH 6.5 (21 days). Greater fungal populations were found at acidic soil pH and alkaline soil pH, in comparison with neutral pH 7.0. Pencillium sp. was found to be more prevalent at acidic pH whilst Aspergillus sp. was found to be more prevalent at pH 7.5-8.0. Bacterial populations were greater at pH 7.5 which was highly correlated with soil ATP levels. It was therefore evident that the greatest rates of degradation were associated with the greatest bacterial population. Soil enzyme activities in general were also greatest at pH 7.5. The converse effect of pH was found with fastest rate of photo-catalytic degradation at the optimal conditions were observed at acidic condition in soil pH 6.5 whilst, the results obtained during biodegradation at the optimal conditions exhibits fastest rate of degradation at alkaline conditions particularly at pH 7.5. Thus, manipulation of soil pH to 7.5 has significant potential to dramatically increase the degradation rate of PAHs.

Petroleum hydrocarbons are the most widespread contaminants in the environment. Interest in the biodegradation of polycyclic aromatic hydrocarbons and compounds (PAHs/PACs) is motivated by their ubiquitous distribution, their low bioavailability, high persistence in soils and their potentially deleterious effects to human health. Identifying the diversity of microorganisms that degrade PAHs/PACs can be utilised in the development of bioremediation techniques. Understanding the mechanisms of bacterial populations to adapt to the presence of pollutants and the extent that lateral transfer of key functional genes occurs, will allow the exploitation of microbial PAC/PAH-degradative capabilities and therefore enhance the successful application of bioremediation strategies. A key aim of this study was to isolate and identify PAC-degrading bacteria for potential use in future bioremediation programmes. A series of PAC enrichments were established under the same experimental conditions from a single sediment sample taken from a highly polluted estuarine site. Distinct microbial community shifts were directly attributable to enrichment with different PAC substrates. The findings of this study demonstrate that five divisions of the Proteobacteria and Actinobacteria can degrade PACs. By determining the precise identity of the PAC-degrading bacteria isolated, and by comparing these with previously published research, this study showed how bacteria with similar PAC degrading capabilities and 16S rRNA signatures are found in similarly polluted environments in geographically very distant locations e.g. China, Italy, Japan and Hawaii. Such a finding suggests that geographical barriers do not limit the distribution of key PAC-degrading bacteria. This is significant when considering the diversity and global distribution of microbes with PAC-degradative capabilities and the potential for utilising these microbial populations in future bioremediation strategies. In the laboratory, enrichment of bacteria able to utilise PAHs has commonly been performed in liquid media, with the PAH dissolved in a carrier solvent. This study found the presence of a carrier solvent significantly affects the resultant microbial population. Although the same sediment sample was used as the bacterial source in all enrichments, different bacterial strains were obtained depending upon the presence of the carrier solvent and the PAH. This is important when considering appropriate methodology for the isolation of PAH-degrading bacteria for future bioremediation programmes. Additionally, the species comprising the resultant population of the enrichment when a carrier solvent was present were similar to previously reported PAH-degrading species. Such a finding necessitates review of previously reported PAH-degrading bacterial species that have been isolated and identified from enrichments using a carrier solvent. Understanding how bacteria acclimatise to environmental pollutants is vital for exploiting these mechanisms within clear up strategies of contaminated sites. Two major lineages of the α subunit of PAH dioxygenases were identified: Actinobacteria and Proteobacteria. Comparison of the α subunit phylogeny with the 16S rRNA phylogeny implies that the PAH-dioxygenases evolved prior to the separation of these phyla or that lateral transfer occurred in the very distant past. No evidence for lateral transfer of the α subunit between the Actinobacteria and Proteobacteria was found in the phylogenetic analyses of this research. Multiple lateral transfer events were inferred between the species of the Actinobacteria and between the classes of the Proteobacteria. The clustering of the taxa within the α subunit phylogeny indicates that lateral transfer of the α subunit gene occurred after the separation of the classes of Proteobacteria and also after the speciation of the γ-Proteobacteria. These findings reveal how bacteria have acclimatised to PAH pollutants through multiple lateral transfer events of a key PAH-degradative gene. This knowledge of the transfer of genetic material will broaden our prospects of exploiting microbial populations.

Thesis (MTech (Environmental Management))--Cape Peninsula University of Technology, 2015. / This study was conducted to investigate the occurrence of PAH degrading microorganisms in two river systems in the Western Cape, South Africa, and their ability to degrade two PAH compounds (acenaphthene and fluorene). A total of 19 bacterial isolates were obtained from the Diep- and Plankenburg Rivers. These microorganisms were first identified phenotypically on various selective and general media (such as nutrient agar, Eosine Methylene Blue and Mannitol Salts Agar), followed by staining and biochemical testing, followed by molecular identification using 16S rRNA and PCR. The isolates were then tested for acenaphthene and fluorene degradation first at flask scale and then in a Stirred Tank Bioreactor at varying temperatures (25ºC, 30ºC, 35ºC, 37ºC, 38ºC, 40ºC and 45ºC). All experiments were run without the addition of supplements, bulking agents, biosurfactants or any other form of biostimulants. Four of the 19 isolated microorganisms were identified as acenaphthene and fluorene degrading isolates. Three of the four microorganisms identified as PAH degrading isolates were Gram negative isolates. Results showed that Raoultella ornithinolytica, Serratia marcescens, Bacillus megaterium and Aeromonas hydrophila efficiently degraded fluorene (99.90%, 97.90%, 98.40% and 99.50%) and acenaphthene (98.60%, 95.70%, 90.20% and 99.90%) at 37ºC, 37ºC, 30ºC and 35ºC, respectively. The degradation of fluorene was found to be more efficient and rapid compared to that of acenaphthene and degradation at Stirred Tank Bioreactor scale was more efficient for all treatments. Throughout the biodegradation experiments, there was an exponential increase in microbial plate counts ranging from 5 x 104 to 9 x 108 CFU/ml. The increase in plate count was observed to correlate with the efficient degradation temperature profiles and percentages. The PAH degrading microorganisms isolated during this study significantly reduced the concentrations of acenaphthene and fluorene and can be used on a larger, commercial scale to bioremediate PAH contaminated river systems. Other factors that influence the optimal expression of biodegradative potential of microorganisms other than temperature and substrate (nutrient) availability, such as pH, moisture and salinity will be investigated in future studies, as well as the factors contributing to the higher fluorene degradation compared to acenaphthene. Furthermore, the structure and toxicity of the by-products and intermediates produced during microbial metabolism of acenaphthene and fluorene should be investigated in further studies.

A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy Johannesburg 2012 / Wastes from mining operations usually contain a suite of pollutants, among them cyanide and its complexes; heavy metals; metalloids and radionuclides. The pollution plume can affect public health through contamination of drinking water supplies, aquatic ecosystems and agricultural soils. As such, waste management and remediation has become an important integral component of mining. Conventional chemical and physical methods are often expensive and ineffective when the pollutant concentrations are very high, so the challenge of developing cost-effective materials with high adsorption efficiencies for pollutants still remains. This research was dedicated to the development of biosorbents with high metal loading capacity for the remediation of mine wastewater, namely: zeolite/bentonite functionalised with microbial components such as histidine, cysteine, sorbitol and mannitol; zeolite/bentonite functionalised with Penicillium-simplicissimum and zeolite-alginate complex generated by impregnating natural zeolite into alginate gel beads. The ability of the fresh water algae, Oedogonium sp. to remove heavy metals from aqueous solutions in batch systems was also assessed. Optimum biosorption conditions for the removal of Co, Cu, Cr, Fe, Hg, Ni, Zn and U (in a single-ion and multi-ion systems) were determined as a function of pH, initial concentration, contact time, temperature, and mass of biosorbent. An increase of adsorption capacity was observed following modification of natural zeolite/bentonite by microbial components with a maximum adsorption capacity obtained at low pH. The FTIR results of the developed biosorbents showed that the biomass has different functional groups that are able to react with metal ions in aqueous solution. Immobilisation of fungi (Penicillium-simplicissimum) on zeolite/bentonite yielded biomass of 600 mg g-1 (10-fold higher than the non-immobilised one) at a pH 4, showing the potential of this sorbent towards remediation of AMD-polluted mine sites. The maximum uptake of metals ions (in a multi-ion system) was higher and constant (40-50 mg g-1) in the inactive fungal biomass (heat-killed) from pH 2 to 7. The uptake of U and Hg increased significantly in the zeolite/bentonite-P.simplicissimum compared to their natural forms due to the presence of the N-H, S-H and COO- groups. iii The pseudo second-order adsorption model was found to be more suitable in describing the adsorption kinetics of metal ions onto biomasses in single- and multi-ion systems with the sorption of nickel being controlled by film diffusion processes (with the coefficient values of 10-7 cm2 s-1). The thermodynamic parameters showed that the adsorption onto developed biosorbents was feasible and spontaneous under the studied conditions. The calculated values of the loading capacities in column adsorption for the natural zeolite/bentonite as well as zeolite/bentonite-P.simplicissimum were close to those obtained in the batch tests, mainly for U and Ni. The bed depth service time model (BDST) was used successfully to fit the experimental data for Ni and U adsorbed on the natural zeolite. This suggested a linear relationship between bed depth and service time, which could be used for scale-up purpose. The developed biosorbents could be regenerated using 1 mol L-1 HNO3 solution for potential re-use. The total decrease in biosorption efficiency of zeolite-Penicillium simplicissimum after five cycles of adsorption-desorption was ≤ 5% which showed that zeolite/bentonite-Penicillium simplicissimum had good potential to adsorb metal ions repeatedly from aqueous solution. On applying it to real wastewater samples, the zeolite-P. simplicissimum biosorbent removed 97% of the metals. Penicillium sp. immobilisation enhanced the potential and makes it an attractive bioremediation agent. The zeolite-alginate sorbent exhibited elevated adsorption capacities for metals. This showed potential for use of such a system for remediation purposes. It also provides a platform to explore the possibility of using zeolite in conjunction with other polysaccharide-containing materials for heavy metal removal from wastewaters. The results obtained in this study have shown that zeolite and bentonite are good supports for biomass. The biofunctionalised zeolite/bentonite systems have potential in removal of heavy metals from wastewaters.

Microrganismos endofíticos apresentam grande diversidade genética e metabólica, com enorme potencial biotecnológico para aplicações em diferentes áreas. A bioprospecção desses microrganismos possibilita a obtenção de novos bioprodutos agrícolas. Endofíticos podem ser aplicados, por exemplo, para a biorremediação de áreas contaminadas ou para o controle de insetos pragas pela produção de compostos entomotóxicos. Apesar de sua importância, ainda existem poucos estudos voltados à bioprospecção da microbiota endofítica em regiões tropicais. Assim, o presente trabalho pretendeu verificar a diversidade de microrganismos endofíticos cultiváveis em milho e a comparar a diversidade de metabólitos desses endofíticos ao de isolados de Citrus. Também foi explorado o potencial dos diferentes endófitos em degradar os principais inseticidas (lufenuron, spinosad, chlorpyrifos ethyl, lambda-cyhalothrin e deltamethrin) utilizados em lavouras de milho para o controle de lagartas de Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera, Noctuidae), para exploração dos mesmos em programas de biorremediação. Finalmente, foi avaliado o potencial entomotoxida dos extratos orgânicos dos endofíticos estudados até a identificação das moléculas ativas. Foram isolados 30 microrganismos endofíticos de milho (27 bactérias e 3 fungos), os quais foram comparados aos endófitos de citros do acervo do Laboratório de Genética de Microrganismos \"Prof. João Lúcio de Azevedo\". Dos isolados obtidos, sete apresentaram capacidade de metabolização dos cinco inseticidas testados, sendo a maioria deles capaz de metabolizar pelo menos um dos inseticidas testados. Ensaios de bioatividade dos extratos orgânicos do cultivo dos endofíticos contra lagartas de S. frugiperda, levaram à identificação de extratos que induziram 100% de mortalidade de lagartas do terceiro ínstar. O isolamento e a caracterização da molécula ativa do extrato produzido pelo isolado LGM-CR-JM-02 - Streptomyces badius, permitiu a identificação da valinomicina (CL50 = 4,38 Mi g/mL) como molécula ativa. Assim, demonstramos que a comunidade de endofíticos pode reunir grande diversidade biológica e, principalmente, metabólica, sendo uma excelente oportunidade para exploração de microrganismos com potencial para biorremediação e produção de compostos com atividade inseticida / Endophytes are microorganisms with great genetic and metabolic diversity, and with a huge biotechnological potential for applications in different areas. The bioprospection of these microorganisms makes possible to obtain new agricultural bioproducts. Endophytes may be applied, for example, to bioremediation of contaminated areas or to the control of pest insects with entomotoxic compounds. Despite its importance, there are few studies focused on the bioprospection of endophytic microbiota in tropical regions. Thus, we investigated the biological diversity of culturable endophytes from maize and compared the diversity of metabolites endophytes from maize and Citrus produced. We also explored the potential of different endophytes to grow in minumum medium containing one of the main insecticides (lufenuron, spinosad, chlorpyrifos ethyl, lambda-cyhalothrin and deltamethrin) applied in maize crops to control the caterpillars Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera, Noctuidae) as the only source of carbon in order to evaluate their potential use in bioremediation programs. Finally, we evaluated the entomotoxic potential of the organic extracts of the endophytes and the fractions up to the identification of the active molecules. In total, thirty maize endophytes (27 bacteria and 3 fungi) and five endophytes isolated from citrus that were deposited at the collection of the Laboratory of Genetics of Microorganisms \"Prof. João Lúcio de Azevedo\" were investigated. Seven out of 35 endophytes tested metabolized the five insecticides used, and most of them were able to metabolize at least one of the tested insecticides. Bioactivity assays of the organic extracts produced from cultured endophytes were fed to third instars of S. frugiperda causing 100% mortality. The isolation and characterization of the active molecule produced by one of these isolates (LGM-CR-JM-02 - Streptomyces badius) led to the identification of valinomycin (LC50 = 4.38 Mi g / mL) as the active molecule. Thus, we demonstrated that endophytes can gather great biological and metabolic diversities, demonstrating endophytes are an excellent opportunity for the identification of microorganisms with potential for bioremediation and production of compounds with insecticidal activity

Textile industries are the major users of dyes in the world. A huge fraction of dyes are discharged out from the textile industries, causing serious damage to the environment. Bioremediation based technologies has been proved to be the most desirable and cost- effective method to counter textile dye pollution. The ability of the microorganisms to decolorize and metabolize dyes can be employed to treat the environment polluted by textile dyes. In this work, a total of 84 bacterial strains were isolated from Kelambakkam Solar Salt Crystallizer ponds (or salterns) and screened for their ability to produce extracellular tannase and laccase enzymes and eventually to decolorize three widely used textile dyes- Reactive Blue 81, Reactive Red 111 and Reactive Yellow 44. Of these 84 strains, 18 strains exhibited tannase activity and 36 strains showed positive laccase enzyme activity. The 11 bacterial strains that displayed both tannase and laccase enzyme activity were screened for their ability to decolorize the three textile azo dyes (100 mg/L). Out of 11 strains only 2 strains i.e., AMETH72 and AMETH77 showed best decolorization (%) in all the three dyes under static condition at room temperature. Repeated- batch immobilization study used to select the most efficient bacterial strain revealed that, isolate AMETH72 was efficient than AMETH77 in decolorizing the dyes. The 16S rRNA sequencing of AMETH72 showed 99% phylogenetic similarity to Halomonas elongata. The dye degradation products analyzed by FTIR and UV-Vis techniques displayed complete disruption of azo linkages and biodegradation of dyes to simpler compounds. The treated dyes also improved growth and total chlorophyll content in Wheat and Green gram seedlings, as compared to the untreated dyes. This indicated the non- toxicity of the biologically degraded dye products. Thus the entire study concluded that halotolerant marine bacteria from the salterns can be effectively used to bioremediate the textile dyes. / Program: MSc in Resource Recovery - Industrial Biotechnology

Mine-impacted water bodies are considered to be one of the most serious threats to the environment. These can be highly acidic and often contain elevated concentrations of sulfate and soluble metals. The microbial generation of H2S by reduction of more oxidized sulfur species, and consequent precipitation of metal sulfides, known as biosulfidogenesis, is a promising technology for remediating acid mine drainage (AMD). The objective of this work was to develop an integrated system for remediating a target AMD at an operating mine in northern Brazil using a single low pH anaerobic sulfidogenic bioreactor (aSRBR) and an aerobic manganese-oxidizing bioreactor. A synthetic version of the mine water, which contained 7.5 mM copper and lower concentrations (< 0.25 mM) of other transition metals (Zn, Ni, Co and Mn) was used in the experimental work. In the first stage, H2S generated in the aSRBR was delivered to an off-line vessel containing synthetic AMD, which removed > 99% copper (as CuS) while no co-precipitation of other metals was apparent. The partly-processed AMD was then dosed with glycerol and fed into the aSRBR where zinc, nickel and cobalt were precipitated. The effect of varying the pH and temperature of the bioreactor was examined, and > 99% of Ni, Zn and Co were precipitated in the aSRBR when it was maintained at pH 5.0 and 35ºC. The bacterial communities, which were included 4 species of acidophilic sulfate-reducing bacteria, varied in composition depending on how the bioreactor was operated, but were both robust and adaptable, and changes in temperature or pH had only short-term impact on its performance. Manganese was subsequently removed from the partly-remediated synthetic AMD using upflow bioreactors packed with Mn(IV)-coated pebbles from a freshwater stream which contained Mn(II)-oxidizers, such as the bacterium Leptothrix discosphora and a fungal isolate belonging to the order Pleosporales. This caused soluble Mn (II) to be oxidised to Mn (IV) and the precipitation of solid-phase Mn (IV) oxides. Under optimised conditions, over 99% manganese in the processed AMD was removed. Metal sulfides (ZnS, CoS and NiS) that had accumulated in the aSRBR over 2 years of operation were solubilised by oxidative (bio)leaching at low pH. With this, ~ 99% Zn, ~ 98% Ni and ~ 92% Co were re-solubilised, generating a concentrated lixiviant from which metals could be selectively recovered in further downstream processes. The use of methanol and ethanol either alone or in combination with glycerol were evaluated as alternative electron donors for biosulfidogenesis. Methanol was not consumed in the bioreactor, though sulfate reduction was not inhibited in the presence of up to 12 mM methanol. In contrast, ethanol was readily metabolised by the bacterial community and sulfate reduction rates were relatively high compared to glycerol. Two acidophilic algae were characterised and their potential to act as providers of electron donors for biosulfidogenesis was also evaluated. Although algal biomass was able to fuel sulfate reduction in pure cultures of aSRB and in the aSRBR, rates were much lower than when either glycerol or ethanol were used.

Bactérias aclimatadas a cobre foram isoladas a partir de amostras de solo e água coletadas na região da Mina de Sossego (Vale, Carajás, PA). Pseudomonas putida sp. foi escolhida, pois, apresentou a maior capacidade sortiva de Cu2+, Q = 40 mg/g. O cultivo em regime de batelada, meio mineral, com glicerol como fonte de carbono, resultou fator de conversão de glicerol a células, YX/S, de 0,49 g/g e velocidade específica máxima de crescimento, mmax, de 0,11 h-1. Alta concentração celular, 90 g/L, foi alcançada em cultivos em regime de batelada alimentada. Promoveu-se sorção de cobre pelas células, por meio de adição contínua ou em pulsos, de solução de CuSO4. A maior sorção específica de cobre, Q, de 30 (mg de Cu2+/g de células), foi verificada na adição por pulsos. Fotos de MET da bactéria na ausência e presença de Cu2+ mostram acúmulo de cobre na membrana e internamente, caracterizando biossorção e bioacumulação. / Bacteria acclimated to copper were isolated from soil and water samples collected in Mina de Sossego (Vale, Carajás, PA). Pseudomonas putida sp. was chosen as it had the highest sorptive capacity for Cu2+, Q = 40 mg/g. The fed-batch culture in mineral medium with glycerol as the carbon source resulted in a glycerol-to-cell conversion factor, YX/S of 0.49 g/g and maximum specific growth rate, mmax of 0.11 h-1. High cell concentration, 90 g/L, was achieved in cultures in fed-batch regimen. Cooper sorption by cells was promoted, by continuous or pulse addition of CuSO4 solution. The highest specific copper sorption, Q, 30 (mg Cu+2/g of cells) was seen with the addition by pulses. TEM photos of the bacteria in the absence and presence of Cu+2 show copper accumulation in the membrane and internally, featuring biosorption and bioaccumulation.

by Wai Lok Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 142-155). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstracts --- p.ii / Contents --- p.vii / List of figures --- p.xiii / List of tables --- p.xvi / Abbreviations --- p.xviii / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Pentachlorophenol / Chapter 1.1.1 --- Applications of pentachlorophenol --- p.1 / Chapter 1.1.2 --- Characteristics --- p.3 / Chapter 1.1.3 --- Pentachlorophenol in the environment --- p.3 / Chapter 1.1.4 --- Toxicity of Pentachlorophenol --- p.6 / Chapter 1.2 --- Treatments of Pentachlorophenol --- p.10 / Chapter 1.2.1 --- Physical treatment --- p.10 / Chapter 1.2.2 --- Chemical treatment --- p.11 / Chapter 1.2.3 --- Biological treatment --- p.13 / Chapter 1.3 --- Biodegradation --- p.14 / Chapter 1.3.1 --- Biodegradation of PCP by bacteria --- p.14 / Chapter 1.3.2 --- Biodegradation of PCP by white-rot fungi --- p.15 / Chapter 1.4 --- Biosorption --- p.24 / Chapter 1.5 --- Proposed Strategy --- p.28 / Chapter 1.6 --- Spent Mushroom Compost / Chapter 1.6.1 --- Background --- p.28 / Chapter 1.6.2 --- Physico-chemical properties of SMC --- p.29 / Chapter 1.6.3 --- As a biosorbent --- p.29 / Chapter 1.6.3.1 --- Factors affecting biosorption --- p.31 / Chapter 1.6.3.2 --- Contact time --- p.31 / Chapter 1.6.3.3 --- Initial pH --- p.32 / Chapter 1.6.3.4 --- Concentration of biosorbent --- p.33 / Chapter 1.6.3.5 --- Initial PCP concentration --- p.34 / Chapter 1.6.3.6 --- Incubation temperature --- p.34 / Chapter 1.6.3.7 --- Agitation speed --- p.35 / Chapter 1.6.4 --- Modeling of adsorption --- p.36 / Chapter 1.6.4.1 --- Langmuir isotherm --- p.36 / Chapter 1.6.4.2 --- Freundlich isotherm --- p.36 / Chapter 1.6.5 --- As a source of PCP-degrading bacteria --- p.38 / Chapter 1.6.5.1 --- Identification of PCP-degrading bacterium --- p.40 / Chapter 1.6.6 --- As a source of fungus --- p.42 / Chapter 1.7 --- Objectives of this Study --- p.43 / Chapter 2. --- Materials and Methods --- p.44 / Chapter 2.1 --- Spent Mushroom compost (SMC) Production --- p.44 / Chapter 2.2 --- Characterization of SMC --- p.46 / Chapter 2.2.1 --- pH --- p.46 / Chapter 2.2.2 --- Electrical conductivity --- p.46 / Chapter 2.2.3 --- "Carbon, hydrogen, nitrogen and sulphur contents" --- p.46 / Chapter 2.2.4 --- Infrared spectroscopic study --- p.47 / Chapter 2.2.5 --- Metal analysis --- p.47 / Chapter 2.2.6 --- Anion content --- p.47 / Chapter 2.2.7. --- Chitin assay --- p.48 / Chapter 2.3 --- Extraction of PCP --- p.49 / Chapter 2.3.1 --- Selection of extraction solvent --- p.49 / Chapter 2.3.2 --- Selection of desorbing agent --- p.49 / Chapter 2.3.3 --- Extraction efficiency --- p.50 / Chapter 2.4 --- Adsorption of Pentachlorophenol on SMC --- p.50 / Chapter 2.4.1 --- Preparation of pentachlorophenol (PCP) stock solution --- p.50 / Chapter 2.4.2 --- Batch adsorption experiment --- p.51 / Chapter 2.4.3 --- Quantification of PCP by HPLC --- p.51 / Chapter 2.4.4 --- Data analysis for biosorption --- p.51 / Chapter 2.4.5 --- Optimization of PCP adsorption --- p.52 / Chapter 2.4.5.1 --- Effect of contact time --- p.52 / Chapter 2.4.5.2 --- Effect of initial pH --- p.52 / Chapter 2.4.5.3 --- Effect of incubation temperature --- p.53 / Chapter 2.4.5.4 --- Effect of shaking speed --- p.53 / Chapter 2.4.5.5 --- Effect of initial PCP concentration and amount of biosorbent --- p.53 / Chapter 2.4.6 --- Adsorption isotherm --- p.53 / Chapter 2.4.7 --- Effect of removal efficiency on reuse of biosorbent --- p.54 / Chapter 2.5 --- Biodegradation by Isolated Bacterium --- p.54 / Chapter 2.5.1 --- Isolation of PCP-tolerant bacteria from mushroom compost --- p.54 / Chapter 2.5.2 --- Screening for the best PCP-tolerant bacterium --- p.54 / Chapter 2.5.3 --- Identification of the isolated bacterium --- p.55 / Chapter 2.5.3.1 --- 16S ribosomal DNA sequencing --- p.55 / Chapter 2.5.3.1.1 --- Extraction of DNA --- p.55 / Chapter 2.5.3.1.2 --- Specific PCR for 16S rDNA --- p.56 / Chapter 2.5.3.1.3 --- Gel electrophoresis --- p.57 / Chapter 2.5.3.1.4 --- Purification of PCR products --- p.57 / Chapter 2.5.3.1.5 --- Sequencing of 16S rDNA --- p.58 / Chapter 2.5.3.2 --- Gram staining --- p.60 / Chapter 2.5.3.3 --- Biolog Microstation System --- p.60 / Chapter 2.5.3.4 --- MIDI Sherlock Microbial Identification System --- p.61 / Chapter 2.5.4 --- Optimization of PCP degradation by PCP-degrading bacterium --- p.62 / Chapter 2.5.4.1 --- Effect of incubation time --- p.63 / Chapter 2.5.4.2 --- Effect of shaking speed --- p.63 / Chapter 2.5.4.3 --- Effect of initial PCP concentration and inoculum size --- p.63 / Chapter 2.5.4.4 --- Study of PCP degradation pathway by isolated bacterium using GC-MS --- p.64 / Chapter 2.6 --- Biodegradation by Fungus Pleurotus pulmonarius --- p.64 / Chapter 2.6.1 --- Optimization of PCP degradation by P. pulmonarius --- p.65 / Chapter 2.6.1.1 --- Effect of incubation time --- p.65 / Chapter 2.6.1.2 --- Effect of shaking speed --- p.65 / Chapter 2.6.1.3 --- Effect of initial PCP concentration and inoculum size --- p.65 / Chapter 2.6.2 --- Study of PCP degradation pathway by fungus using GC-MS --- p.65 / Chapter 2.6.3 --- Specific enzyme assays --- p.66 / Chapter 2.6.3.1 --- Extraction of protein and enzymes --- p.66 / Chapter 2.6.3.2 --- Protein --- p.66 / Chapter 2.6.3.3 --- Laccase --- p.67 / Chapter 2.6.3.4 --- Manganese peroxidase (MnP) --- p.67 / Chapter 2.6.4 --- Microtox® assay --- p.67 / Chapter 2.7 --- Statistical Analysis --- p.68 / Chapter 3. --- Results --- p.69 / Chapter 3.1 --- Physico-chemical Properties of SMC --- p.69 / Chapter 3.2 --- Extraction Efficiency and Desorption Efficiency of PCP --- p.69 / Chapter 3.3 --- Batch Adsorption Experiments --- p.76 / Chapter 3.3.1 --- Optimization of adsorption conditions --- p.76 / Chapter 3.3.1.1 --- Effect of contact time --- p.76 / Chapter 3.3.1.2 --- Effect of initial pH --- p.76 / Chapter 3.3.1.3 --- Effect of shaking speed --- p.79 / Chapter 3.3.1.4 --- Effect of incubation temperature --- p.79 / Chapter 3.3.1.5 --- Effect of initial PCP concentration and amount of biosorbent --- p.79 / Chapter 3.3.2 --- Reuse of SMC --- p.83 / Chapter 3.3.3 --- Isotherm plot --- p.83 / Chapter 3.4 --- Biodegradation by PCP-degrading Bacterium --- p.86 / Chapter 3.4.1 --- Isolation and purification of PCP-tolerant bacteria --- p.86 / Chapter 3.4.2 --- Identification of the isolated bacterium --- p.90 / Chapter 3.4.2.1 --- 16S rDNA sequencing --- p.90 / Chapter 3.4.2.2 --- Gram staining --- p.90 / Chapter 3.4.2.3 --- Biolog MicroPlates Identification System --- p.90 / Chapter 3.4.2.4 --- MIDI Sherlock Microbial Identification System --- p.90 / Chapter 3.4.3 --- Growth curve of PCP-degrading bacterium --- p.90 / Chapter 3.4.4 --- Optimization of PCP degradation by PCP-degrading bacterium --- p.97 / Chapter 3.4.4.1 --- Effect of incubation time --- p.97 / Chapter 3.4.4.2 --- Effect of shaking speed --- p.97 / Chapter 3.4.4.3 --- Effect of initial PCP concentration and inoculum size of bacterium --- p.101 / Chapter 3.4.5 --- Determination of breakdown products of PCP by PCP-degrading bacterium --- p.101 / Chapter 3.5 --- Biodegradation by Fungus Pleurotus pulmonarius --- p.103 / Chapter 3.5.1 --- Growth curve of P. pulmonarius --- p.103 / Chapter 3.5.2 --- Optimization of PCP degradation by P. pulmonarius --- p.103 / Chapter 3.5.2.1 --- Effect of incubation time --- p.103 / Chapter 3.5.2.2 --- Effect of shaking speed --- p.103 / Chapter 3.5.2.3 --- Effect of initial PCP concentration and inoculum size of fungus --- p.108 / Chapter 3.5.3 --- Determination of breakdown products of PCP by P. pulmonarius --- p.108 / Chapter 3.5.4 --- Enzyme assays --- p.108 / Chapter 3.6 --- Integration of Biosorption by SMC and Biodegradation by P. pulmonarius --- p.112 / Chapter 3.6.1 --- Evaluation of PCP removal by an integration system --- p.112 / Chapter 3.6.2 --- Evaluation of toxicity by Micortox® assays --- p.112 / Chapter 4. --- Discussion --- p.115 / Chapter 4.1 --- Physico-chemical Properties of SMC --- p.115 / Chapter 4.2 --- Extraction Efficiency and Desorption Efficiency of PCP --- p.116 / Chapter 4.3 --- Batch Biosorption Experiment --- p.117 / Chapter 4.3.1 --- Effect of contact time --- p.117 / Chapter 4.3.2 --- Effect of initial pH --- p.118 / Chapter 4.3.3 --- Effect of shaking speed --- p.120 / Chapter 4.3.4 --- Effect of incubation temperature --- p.120 / Chapter 4.3.5 --- Effect of initial PCP concentration and amount of biosorbent --- p.121 / Chapter 4.3.6 --- Reuse of SMC --- p.122 / Chapter 4.3.7 --- Modeling of biosorption --- p.122 / Chapter 4.4 --- Biodegradation of PCP by PCP-degrading Bacterium --- p.124 / Chapter 4.4.1 --- Isolation and purification of PCP-tolerant bacterium --- p.124 / Chapter 4.4.2 --- Identification of the isolated bacterium --- p.125 / Chapter 4.4.3 --- Optimization of PCP degradation by PCP-degrading bacterium --- p.126 / Chapter 4.4.3.1 --- Effect of incubation time --- p.126 / Chapter 4.4.3.2 --- Effect of shaking speed --- p.128 / Chapter 4.4.3.3 --- Effect of initial PCP concentration and inoculum size of bacterium --- p.128 / Chapter 4.4.4 --- PCP degradation pathway by S. marcescens --- p.129 / Chapter 4.5 --- Biodegradation of PCP by Pleurotus pulmonarius --- p.130 / Chapter 4.5.1 --- Optimization of PCP degradation by P. pulmonarius --- p.130 / Chapter 4.5.1.1 --- Effect of incubation time --- p.131 / Chapter 4.5.1.2 --- Effect of shaking speed --- p.131 / Chapter 4.5.1.3 --- Effect of initial PCP concentration and inoculum size of fungus --- p.131 / Chapter 4.5.2 --- Enzyme activities --- p.132 / Chapter 4.5.3 --- PCP degradation pathway by P. pulmonarius --- p.133 / Chapter 4.6 --- Comparison of PCP Degradation between S.marcescens and P. pulmonarius --- p.133 / Chapter 4.7 --- Integration of Biosorption by SMC and Biodegradation by P. pulmonarius --- p.135 / Chapter 4.8 --- Evaluation of toxicity by Microtox® assay --- p.135 / Chapter 4.9 --- Comparison of PCP Removal by Integration System of Sorption and Fungal Biodegradation and Conventional Treatments --- p.136 / Chapter 4.10 --- Further Investigations --- p.137 / Chapter 5. --- Conclusion --- p.139 / Chapter 6. --- References --- p.142