The Immobilisation, Degradation or Monitoring of Pollutants from a Biological Origin
Removal of a material from an environment takes one of two routes: it is either degraded or immobilised by a process which renders it biologically unavailable for degradation and so is effectively removed.
Immobilisation can be achieved by chemicals excreted by an organism or by chemicals in the neighbouring environment which trap or chelate a molecule thus making it insoluble. Since virtually all biological processes require the substrate to be dissolved in water, chelation renders the substance unavailable. In some instances this is a desirable end result and may be viewed as a form of remediation, since it stabilises the contaminant. In other cases it is a nuisance, as digestion would be the preferable option. Such ‘unwanted’ immobilisation can be a major problem in remediation, and is a common state of affairs with aged contamination. Much research effort is being applied to find methods to reverse the process.
Degradation is achieved by metabolic pathways operating within an organism or combination of organisms, sometimes described as consortia. These processes are the crux of environmental biotechnology. Such activity operates through metabolic pathways functioning within the cell, or by enzymes either excreted by the cell or, isolated and applied in a purified form.
Biological monitoring utilises proteins, of which enzymes are a subset, pro-duced by cells, usually to identify, or quantify contaminants. This has recently developed into an expanding field of biosensor production.