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The introduction of lux genes, able to express bioluminescence, into terrestrial bacteria enabled the optimisation of a bioluminescence-based bioassay that was environmentally relevant. Individual assay parameters such as growth phase, cell washing, lyophilisation, pH tolerance and temporal response to a range of metal and xenobiotic pollutants were evaluated. The effects of a range of pollutants upon the metabolic response of the lux-marked organisms were assessed using declines in bioluminescence. The lux -based bioassay proved more sensitive to the sub-lethal effects of metal pollutants than tests relying on culturability. Uncontaminated soils were spiked with metal and xenobiotic solutions both as single pollutants and in combination with other contaminants. Relative toxicity of metal and xenobiotic pollutants in soil systems were investigated using ecotoxicity assays based upon lux-marked constructs of Rhizobium leguminosarum biovar trifolii (an important associative nitrogen fixer) and the respiration of the microbial community. The lux-marked bioassay proved to be more sensitive than the community microbial assay to the presence of multiple contaminants at sub-lethal concentrations. The relative toxicities of metal and organic xenobiotic compounds were shown to be time dependent and better represented using chronic assaying of lux-marked microorganisms. Following a field trial involving the application of paper mill sludge to land and subsequent crop failure a rapid diagnosis of soil pollutants was required. A suite of ecotoxicity assays including lux-based bioassays, respirometry and enzyme activity were used to assess the toxicity of paper mill sludge to the soil microbial biomass. The selected lux-marked soil bacteria showed potential for use as rapid, field-based screening techniques to provide early warning of the potential hazards of waste application.

This report details the study of a freshwater stream carrying high doses of heavy metals into an already affected fjord. The purpose is to find out how the measured levels of heavy metals vary across the industrial area, and if these levels are posing an environmental or health threat to the surroundings. According to the water directive of the European Union, all waters should be protected in order to reach ’good status’, and deterioration should be prevented. To keep track of the status of waters, environmental quality standards (limit values known as EQS) are used by Norwegian environmental authorities to indicate pollution levels. All measured contents in this report are therefore compared with EQS or similar limit values. New water samples were taken along the stream and in the soil and sediments during the spring of 2016. The measured levels were then compared with older water samples, and showed clear variations across the industrial area for most of the substances. For some substances, high levels of pollution were found in the soil, sediment and water. Despite this, most measured heavy metals pose no threat environmentally or health-wise due to the very alkaline water in the stream, likely to leave most metals nonbioavailable. Although the stream is heavily loaded with various heavy metals, its lack of finer matter prevents metals from binding to organic ligands, allowing the stream to become more of a transportation means than a place for accumulating metals in the soil and sediments.

by Wong Pik-kwan. / Thesis submitted in: September 1997. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 116-139). / Abstract also in Chinese. / ABSTRACT --- p.i / ACKNOWLEDGEMENT --- p.iii / TABLE OF CONTENTS --- p.iv / LIST OF TABLES --- p.viii / LIST OF FIGURES --- p.ix / Chapter CHAPTER ONE --- GENERAL INTRODUCTION --- p.1 / Chapter CHAPTER TWO --- LITERATURE REVIEW / Chapter 2.1 --- Introduction --- p.4 / Chapter 2.2 --- Heavy metals --- p.6 / Chapter 2.3 --- Mechanisms of metal toxicity --- p.9 / Chapter 2.4 --- Toxic effects of metals on marine organisms --- p.10 / Chapter 2.4.1 --- Cadmium --- p.10 / Chapter 2.4.2 --- Chromium --- p.10 / Chapter 2.4.3 --- Copper --- p.11 / Chapter 2.4.4 --- Lead --- p.12 / Chapter 2.4.5 --- Nickel --- p.12 / Chapter 2.4.6 --- Zinc --- p.13 / Chapter 2.5 --- Metal uptake and elimination in marine organisms --- p.14 / Chapter 2.5.1 --- Uptake of metals --- p.14 / Chapter 2.5.2 --- Elimination of metals --- p.15 / Chapter 2.5.3 --- Metal detoxification system in fish --- p.16 / Chapter 2.6 --- Heavy metals in marine fish --- p.17 / Chapter 2.7 --- Bioaccumulation --- p.20 / Chapter 2.7.1 --- Models of metal accumulation --- p.21 / Chapter 2.7.2 --- Compartment model --- p.21 / Chapter 2.7.3 --- Physiologically based pharmacokinetic (PB-PK) model --- p.22 / Chapter 2.8 --- The influence of environmental factors on bioaccumulation of metals --- p.23 / Chapter 2.8.1 --- Temperature --- p.23 / Chapter 2.8.2 --- Salinity --- p.23 / Chapter 2.8.3 --- Organic matter --- p.24 / Chapter 2.8.4 --- pH --- p.25 / Chapter 2.8.5 --- Chelators and surfactants --- p.25 / Chapter 2.8.6 --- Other metals --- p.26 / Chapter 2.9 --- Biological effects of heavy metals on man --- p.26 / Chapter 2.10 --- The use of biological indicator organisms for metal pollution --- p.28 / Chapter CHAPTER THREE --- HEAVY METAL CONCENTRATIONS IN CULTURED MARINE FISH IN HONG KONG / Chapter 3.1 --- Introduction --- p.31 / Chapter 3.2 --- Materials and methods --- p.36 / Chapter 3.2.1 --- Sampling --- p.36 / Chapter 3.2.2 --- Water analysis --- p.36 / Chapter 3.2.3 --- Sediment analysis --- p.39 / Chapter 3.2.4 --- Mussel analysis --- p.40 / Chapter 3.2.5 --- Fish analysis --- p.40 / Chapter 3.2.6 --- Quality control and statistical analysis --- p.41 / Chapter 3.3 --- Results --- p.42 / Chapter 3.3.1 --- Seawater --- p.42 / Chapter 3.3.2 --- Sediment --- p.46 / Chapter 3.3.3 --- Mussel --- p.46 / Chapter 3.3.4 --- Fish --- p.50 / Chapter 3.4 --- Conclusion --- p.67 / Chapter 3.4.1 --- "Metal concentration in seawater, sediment, green mussel and fish" --- p.67 / Chapter 3.4.2 --- Accumulation of heavy metals in different tissues of cultured fish --- p.69 / Chapter 3.4.3 --- Relationship between the body weight and metal accumulation --- p.71 / Chapter 3.4.4 --- Heavy metal pollution in fish culture sites --- p.72 / Chapter 3.4.5 --- Selection of fish culture site --- p.72 / Chapter CHAPTER FOUR --- ACUTE AND SHORT-TERM EFFECTS OF COPPER(II) IONS ON SPARUS SARBA / Chapter 4.1 --- Introduction --- p.76 / Chapter 4.2 --- Materials and methods --- p.79 / Chapter 4.2.1 --- Experimental animals --- p.79 / Chapter 4.2.2 --- Determination of the 96 hour median lethal concentrations --- p.19 / Chapter 4.2.3 --- Determination of growth rate --- p.80 / Chapter 4.3 --- Results --- p.82 / Chapter 4.3.1 --- Determination of the 96 hour median lethal concentrations --- p.82 / Chapter 4.3.2 --- Determination of growth rate --- p.82 / Chapter 4.3.3 --- Distribution of Cu concentration in whole body and different tissues of S. sarba --- p.82 / Chapter 4.4 --- Conclusion --- p.91 / Chapter 4.4.1 --- Determination of the 96 hour median lethal concentrations --- p.91 / Chapter 4.4.2 --- Determination of growth rate --- p.93 / Chapter 4.4.3 --- Distribution of Cu concentration in whole body and different tissues of S. sarba --- p.94 / Chapter CHAPTER FIVE --- ACCUMULATION AND ELIMINATION OF COPPER(II) IONS TO SPARUS SARBA / Chapter 5.1 --- Introduction --- p.96 / Chapter 5.2 --- Materials and methods --- p.98 / Chapter 5.2.1 --- Experimental animals --- p.98 / Chapter 5.2.2 --- Uptake and elimination of Cu ion in S. sarba during continuous exposure to waterborne Cu --- p.98 / Chapter 5.3 --- Results --- p.100 / Chapter 5.4 --- Conclusion --- p.108 / Chapter CHAPTER SIX --- GENERAL CONCLUSION --- p.112 / CHAPTER SEVEN REFERENCES --- p.116

Protein folding and stability are essential for protein function. Changes in these characteristics can lead to altered physiological states and to the development of certain pathologies. While extensive research has focused on the stability of soluble proteins, membrane protein stability has received much less attention. Understanding the stability of membrane proteins can provide insight into folding mechanisms and the etiology of various pathologies. The purpose of this project is to prepare molecular tools to perform comparative studies of homologous membrane proteins that are found in various environments. To this end, thermophilic (Pyrococcus abyssi), mesophilic (Escherichia coli), and psychrophilic (Exiguobacterium 255-15) transmembrane Zn2+ transporting ATPases were cloned, expressed, and functionally characterized to correlate thermostability with optimal functional temperatures. In addition, the lipid environments and composition (rigid or fluid lipids) may also be involved in determining the stability of membrane proteins. Toward exploring the role of extremophilic lipids, Archaeoglobus fulgidus and Thermotoga maritima were grown and lipids were extracted. Availability of these molecular tools will enable physical-chemical studies toward understanding the structural factors that determine functional stability.

Heavy metals and hydrocarbons are persistent pollutants in the environment. Problems associated with the cleanup of sites contaminated by metals and hydrocarbons have demonstrated the need to develop remediation technologies that are feasible, quick, and effective in a wide range of physical settings. Experiments were conducted to investigate the efficiency of silica encapsulation and the factors that influence its performance. Analysis was done by ICP-OES and GC-FID for metals and hydrocarbons respectively. This technology was tested using sodium silicate and ChemcapTM. Soils and water contaminated with hydrocarbons and heavy metals were successfully remediated by silica encapsulation. The silica coating was stable under both acidic and alkaline conditions. A new product that is based on sodium silicate formulation was developed and was more effective at encapsulating hydrocarbons and heavy metals. Laboratory tests indicated that it is more effective in an acidic medium and it continues to strengthen with time. Metal encapsulation was affected by the sizes of metal ions and the presence of hydrocarbons.