January 2000

This review assesses the potential of selected new biotechnological methods for environmental monitoring that may eventually supersede, or a least complement, present monitoring methods. The methods primarily utilise microorganisms and advantages of using microorganisms for environmental monitoring are discussed.

New single-species bioassays using both algae and bacteria are outlined. Immobilised algal bioassays, used to assess the trophic status of waters have potential for medium to long term monitoring or classification of waters. Several new developments in the measurement of bioluminescence, using GMOs (Genetically Modified Organisms), to bioassay soils and waters are discussed. This technology is a derivative of that already in use (Microtox) and there are several potential benefits in using such biosensors that could be readily assimilated into existing monitoring schemes as long as legislative issues associated with the use of GMOs are clarified.

Among the various community measurements, Biolog, based upon multi-substrate utilization or CLPPs (Community Level Physiological Profiles), is being used increasingly. The results of studies on pollution due to heavy metals, hydrocarbons, chlorinated compounds, other xenobiotics, pesticides and radiation contamination suggest the method can be sensitive. It’s main advantage is the simplicity and speed of use but more research is required to establish the limits of sensitivity and its relevance for assessing oligotrophic communities.

Several new methodologies, based on DNA/RNA analyses, are reviewed including sequence analysis, %G+C content (percentage of the nucleotides, guanine and cytosine), PCR (Polymerase Chain Reaction) based methods, DGGE (Denaturing Gradient Gel Electrophoresis) and TGGE (Temperature Gradient Gel Electrophoresis). However, most are relatively new and currently too expensive to be considered for routine analysis in the short to medium term. Their long term potential is promising especially for investigative or diagnostic work.

The analysis of communities by extracting their lipid biomarkers, and in particular their PLFAs (Phospholipid Fatty Acids), has been applied extensively to air, water, sediment and soil environments. PLFA analysis has been shown to be particularly sensitive to heavy metal contamination in soils. As with Biolog, more work on standardization, the establishment of background data and comparison with other methods is required.

Recommendations for the standardisation and adoption of PLFAs and Biolog for the risk assessment of contaminated soils and sediments and for comparing such methods with traditional invertebrate monitoring in aquatic environments are made.

Algae; Bacteria; Bioassays; Biolog; Biosensors; Community analysis; Ecotoxicity measurements; Lux gene; Nucleic acid technologies; PLFA analysis; Pollutants.

Copies of this report are available from the Foundation, price £15.00, less 20% to FWR Members.