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Electric bacteria will show the way to soil contamination

In a new collaborative project called BIOMAP, researchers, the business community and government agencies and institutions will utilize electrical signals from soil bacteria to map soil-contaminated sites in Denmark. The Innovation Fund Denmark has invested nearly 12 million DKK in the project, which is intended to make mapping of soil contamination quicker, cheaper and kinder to the environment.

When standing on a contaminated site, it is often difficult to determine exactly where the contamination lies. In Denmark alone, the Regions and private owners spend about 250 million DKK annually in studying and mapping soil contamination of Denmark's approximately 35,000 contaminated sites.

Now scientists and engineers are going to develop a new and inexpensive method to replace some of the traditional – and most often costly and time-consuming – drilling and chemical analyses used today to map soil contamination.

Contamination degrading bacteria make electric signals

The new method is based on a discovery made by researchers at Aarhus University of bacteria in the seabed that make electric currents in connection with their metabolism. Preliminary measurements show that this phenomenon is also present at soil contaminations and that it gives signals that are powerful enough to be measured on the soil surface.

This makes it possible to carry out quick and gentle surface measurements and in this way map out the location of contamination on a site. In so doing, the Regions can save large amounts of money, and the method minimizes the destruction of green areas, pavements, and installations in the soil.

- We are going to develop a technique that makes mapping of soil contamination both cheaper and gentler. At the same time, we are counting on a business adventure as a result of this, project manager and researcher at Aarhus University, Lars Riis Damgaard says and adds:

- As a side effect, we gain more knowledge about microbes’ contamination degradation and thereby contribute to maintain Denmark's strong position in the environmental field.

Development and export of knowledge, computer models and equipment

It is not a new discovery that measurable electrical signals can be found on the soil surface above contaminations. However, when a research group at Aarhus University discovered the so-called 'cable bacteria', which are long chains of bacterial cells surrounded by a common electrical conductor, it was documented for the first time how such deviations could occur. This insight is combined in the new project with the other partners' expertise in chemistry, geophysics, computer modelling and measuring equipment.

In this project, the concept is tested on a number of contaminated sites, and the gained knowledge will be used to develop equipment that can carry out electrical measurements, as well as a computer model to calculate how deep the contamination lies beneath the surface.

- At a global level, huge industrial areas around the large cities are being included for housing each year and on many of these sites, soil contamination must first be mapped and managed to ensure a healthy environment in the newly built homes, Per Loll says, development manager with the project partner DMR A/S.

The developed equipment will therefore be commercialised and is expected to have a very high export potential.

Interdisciplinary cooperation in several sectors

The project is a collaboration between microbial researchers (Center for Electromicrobiology) and geophysics researchers from Aarhus University, who are responsible for the scientific development of measuring equipment and signal interpretation. In addition, the consulting engineering firm DMR A/S will ensure a market-oriented development, while the Central Denmark Region and the Capital Region of Denmark will add a customer perspective and knowledge of contaminated sites.


  • Lars Riis Damgaard, researcher at the Center for Electromicrobiology, Aarhus University
     26 35 36 09, lrd@bios.au.dk
  • Jens Bomholt, Head of Press and Media Communication, Innovation Fund Denmark, (+45) 6190 5019
    61 90 50 45, jens.bomholt@innofond.dk

About the Partners:

  • Center for Electromicrobiology (CEM)
    The CEM researchers study the newly discovered cable bacteria, which in chains form centimeter long electrical wires. By doing so the cable bacteria can connect various biochemical processes with electric currents and are a particularly prominent example of the rapidly growing research field of electromicrobiology. CEM is located at Aarhus University, Section for Microbiology and combines expertise in the application and development of methods in microbiology, molecular biology, electrochemistry, measuring technology and nanoscience.
  • The Hydro-Geophysics Group (HGG)
    HGG at the Department of Geoscience at Aarhus University does  research at the highest level with the overall goal of developing methods of knowledge-based mapping and modelling of water resources for the benefit of society. HGG combines geophysical instrument development with advanced data processing and inversion algorithms and hydrological modelling. The group works with projects in Denmark and internationally and has produced a large number of publications on the use of geophysical methods for the mapping of geology, geotechnical engineering and groundwater resources.
  • Dansk Miljørådgivning (DMR A/S)
    DMR A/S (Danish Environmental Consulting) is a rapidly growing specialized consulting engineering firm with an expertise in contaminated soil, groundwater and indoor climate, contaminated building materials, work environment, geotechnical engineering and related fields of work. Currently DMR has 15 regional offices in Denmark and Norway and has one of the strongest development profiles in the Danish environmental consulting industry. In recent years, DMR has had an increased focus on the development of equipment for smart sampling of environmental samples, as well as solutions to achieve greater robustness in contamination surveys and risk assessments.
  • The Central Denmark Region and the Capital Region Denmark 
    The Danish regions are responsible of preventing, eliminating or reducing harmful effects of soil contamination on groundwater, human health and the environment. This is done by investigating and cleaning up old, contaminated industrial sites. This is a very big task, and the regions are therefore deeply involved in the development of cheaper, better and more sustainable technologies to solve the task. The regions have extensive experience of the soil contamination task and its scale in Denmark, and the problems normally associated with investigation and clean-up of soil and groundwater contaminants.