Interfacial Biology – Microorganisms on surfaces

Fraunhofer Institute for Interfacial Engineering and Biotechnology

Microorganisms like fungi and bacteria are omnipresent in nature and play an important role in all elemental-circuits. Therefore they are of vital importance to the continuity of ecosystems. They are even useful assistants to men: We employ them for brewing beer, baking bread, cleaning waste water or producing vitamins and antibiotics.

Though most of the time their adverse effects are detected so much faster: Contaminations in medical departments and industrial productionlines bring immense costs and cause heavy losses by rotting raw material or producing toxic by-products.

At the Fraunhofer IGB facility the relevance of biofilms was detected and their application promoted very early, e.g. to produce valuable products or to clean industrial and municipal wastewater. But as well their avoidance and abatement ist encouraged by innovative techniques. These requirements raised the demand for effective qualitative and quantitative evaluation methods to detect surfacebound microorganisms in medical engineering, construction and technical applications.

Fields of research

  • Microbiological evaluation of surfaces and components in medical engineering, construction, technical applications, hygiene
  • Immobilization of microorganisms on surfaces
  • Biofilm prevention and use
  • Inactivation and/or reduction of microbial cells by photocatalytical processes, antimicrobial surfaces, plasma sterilization, UV-treatment, ultrasound or filtration processes
  • Use of signalling molecules
  • Development and evaluation of (bio-)technical processes

Microbiological evaluation

The Fraunhofer IGB has developed standardized methods for the microbiological evaluation of the hygienic status of the technical surfaces, and media as well as water.

Evaluation of the hygiene status

  • Measurement of cell counts
  • Quantification of colony forming units
  • Identification of microorganisms
  • Biosensors for detection of microbial interaction with chemical or biological relevant substances

On that basis we develop adapted solutions for different applications

Good to know

Projects

  • Practical test method with flow cells for biofilms
  • more details
  • Evaluating the hygienic situation of effluents
  • more details
  • Microbiological investigations into photocatalytic surfaces – a field trial
  • more details
  • AquaBioTox: Biological sensors for online monitoring of drinking water pipes
  • more details
  • Photocatalytic coatings to counteract microorganisms on surfaces
  • more details

Services

Microbiological evaluation

  • Evaluation of microbial impurity on surfaces and in production-integrated media (e. g. water, raw materials, industrial products)
  • Estimation of antimicrobial properties of specially coated surfaces
  • Selection and cultivation of capable organisms to judge surfaces
  • Development of methods for special demands and new requirements
  • more details: Established evaluation methods and test set-ups

Development of procedures and innovative materials

  • Creating procedures to minimize the microbial and chemical load in various sectors (e. g. sterilization processes, elongation of retention times for cleansing baths, process water treatment, cost-efficient recycling of production-integrated media and waste water treatment)
  • Development of innovative materials to reduce the upcoming of biofilms affecting packaging supply, pipelines, medical equipment and / or for the design of future work spaces

Bundled competence for complex requirements

The interdisciplinary cooperation between different departments of Fraunhofer IGB and also with other Fraunhofer institutes provides a close connection of material development chemical-physicals and biological revision, in which interested industrial partners are integrated in the context of mission oriented research. The aim is to create adapted solutions for each of these complex requirements.

Equipment

  • Microbiological laboratories with modern equipment as well as an appropriately qualified team permit the handling of microorganisms in the risk groups 1 and 2.
  • Activation units are available for the examination of photocatalytically finished surfaces, in which a biological characterization of the specimens can be carried out under defined conditions.
  • Qualitative and quantitative methods of measurement to compare different materials and products.
  • Methods for the evaluation of the adhesion properties and the biofilm formation under static and dynamic conditions.
  • Outdoor experiments to study the influence of weather conditions are planned on request.

Test organisms

Bacteria, fungi and algae are used as test organisms. The range includes studies with defined test strains of axenic cultures (e.g. Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Aspergillus niger, Scenedesmus spec.) as well as the use of mixed populations typical of the location. The choice of the test organisms is based on the cell wall composition of the organisms, well-known resistances, genetically determined metabolic properties, the fields of application intended for the products as well as the formation of the biofilm.

On the basis of the equipment available and the expert qualifications, the Fraunhofer IGB is able to work with microorganisms of the high-risk group 1 and 2. In addition, genetically modified strains of relevant organisms were developed that produce fluorescent proteins, which are expressed depending on the stage of the biofilm formation.