Monitoring pollution enzymes

DNA analysis, performance of polymerase chain reactions, clinical assays for pH, enzymes, proteins, oxygen etc., trace pollution monitoring and other sorts of biological analyzes are at the focus of recent developments [5]. Another reference lists environmental monitoring (including speciation), clinical monitoring, and quality control in production processes as applications of pTAS equipment in chemical analysis [30]. 

For biocatalysts, binding is followed by a chemical reaction and release of products. Enzymes were the first catalysts used in biosensors and a large number of these natural proteins are available. Although they remain the most commonly employed, the use of purified enzymes is not always satisfactory and in some situations cell preparations containing the required enzymes in their natural environment may be preferable. This approach reduces specificity but can be used to advantage when the analysis of the range of related substances is required as in the case of pollution monitoring. 

Obviously we must obtain considerably more information concerning the causative nature of this interesting enzyme response before any of the species we are currently investigating can be routinely used to monitor the marine environment for pollutants. 

Cell components or metabolites capable of recognizing individual and specific molecules can be used as the sensory elements in molecular sensors [11]. The sensors may be enzymes, sequences of nucleic acids (RNA or DNA), antibodies, polysaccharides, or other reporter molecules. Antibodies, specific for a microorganism used in the biotreatment, can be coupled to fluorochromes to increase sensitivity of detection. Such antibodies are useful in monitoring the fate of bacteria released into the environment for the treatment of a polluted site. Fluorescent or enzyme-linked immunoassays have been derived and can be used for a variety of contaminants, including pesticides and chlorinated polycyclic hydrocarbons. Enzymes specific for pollutants and attached to matrices detecting interactions between enzyme and pollutant are used in online biosensors of water and gas biotreatment [20,21]. 

Enzyme induction and/or isoenzyme variation have been used to characterise widely different phenomena. These enzymatic parameters were shown to be useful criteria for monitoring air pollution (Keller, 1974 Fliickiger et al., 1978 Rabe and Kreeb, 1979), for ecogenetic characterisation of plant populations (Verkleij et al, 1980 Triest, 1991), for the study of callus tissue differentiation (Coppens and Gillis, 1987) and plant development and differentiation (Scandalios, 1974). The evaluation of phytotoxicity of metal-polluted soils and other substrates can also be realised by enzymatic parameters. 

In addition, important detoxification enzymes such as cytochrome P450 monooxygenases and glutathione S-transferases can be used as biomarkers for monitoring pesticide pollution. For example, Jensen et al. (1991) showed that treatment of rainbow trout (Onco-rhynchus mykiss) with endosulfan (as low as 8.3 ppb) induced two microsomal monooxygenase activities (7-ethoxyresorifin O-demethylase and aldrin epoxidase). Martinez-Lara et al. (1996) found that dieldrin and malathion induced individual isozymes of GST in the gilthread seabream, Sparus aurata. 

Analytical usefulness of immobilized bioluminescent assays depends on properties of their immobilized enzymes. The most popular application of immobilized bioluminescent systems is for analysis and monitoring of chemical and biochemical analytes and environmental pollutants. The wide range of analytes measured and monitored by immobilized bioluminescent systems has been reviewed. Stability, sensitivity, precision, and effects of interfering substances and the microenvironment are also discussed. 

Bioluminescence bioassays based on luminous bacteria and coupled enzyme system NADH-FMN-oxidoreductase-luciferase were adapted for monitoring the saline-water conditions of Lake Shira (Khakasia, Siberia). The differences in bioluminescence responses have been found to be related to the salt composition and the oxidation-reduction properties of water. Bioluminescent kinetics parameters, which are mostly sensitive to pollution under conditions of saline water, have been observed. Figure 1 shows the typical bioluminescence kinetics of the samples of water due to anthropogenic influence (beach) and control clear water (non-recreational area). 

Enzyme immunoassays (EIA) have been developed which offer a quick and inexpensive method to detect in water low levels of several environmental pollutants. The simplicity of some EIA protocols allow personnel with minimal training to screen samples. The use of an EIA as a screening method and chromatography for confirmation appears to be a cost effective approach to monitor large numbers of samples. 

The responses of soil enzymes activities to pollutant exposure could be used to evaluate the soil microbial properties. Enzyme activity was widely used to monitor soil pollution and remediation process I . Catalase in the soil can undermine the hydrogen peroxide which was toxic to the organisms. Catalase could be induced by environmental harmful factors, and the activity status reflects the stress situation of the environment to some extent P . 

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