- Biofilms as accelerators of co-evolution for improving bacterial consortia performance.

In this project, we will characterise the molecular mechanisms behind short-term co-adaption in bacteria, and use this insight to develop a new methodology that can improve bacterial performance.

Background and aim

Traditionally, bacterial cultures used in food production often contain different species to obtain the desired texture etc. during processing. However, the selection and risk assessment prior to application of the microorganisms follow traditional pure-culture principles.

Thus, the standard pipeline for optimization of bacterial cultures involves single clone isolation and characterisation, after which the bacterial isolates are joined in co-cultures and applied as defined starter cultures for fermentation and/or flavour development. Such defined starter cultures differ from the non-customised, traditional starter cultures, which are used for years to decades in milk fermentation and cheese ripening and propagated as consortia by continuous transfer from product batch to product batch without isolation of individual strains. This practice is not commonly applied in modern biotechnological food producing industries, due to difficulties in keeping track of individual clones and reproducibility requirements in repeated production. In addition, non-defined cultures are less cost effective than defined consortia. Thus, isolation and identification of pure bacterial isolates are inevitable steps in starter culture design, but may not be the best, as isolation and selection criteria are based on performance of individual strains, that are not optimally adapted to the other members of the applied co-culture.

The aim of this project is to reveal the dynamics, prevalence and underlying mechanisms of short-term bacterial co-adaptation. We will use this to develop a method for short-term co-cultivation that will enhance properties of consortia in current production processes.


This research project will provide a method for improvement and validation for food industry fermentation and improve knowledge on bacterial co-adaption in multispecies biofilms. The technology developed is expected to be applicable to any process that depend on activity of defined bacterial consortia. In broader terms, the project outcome will be relevant for strategies used to exploit and prevent multispecies biofilms, as the process steps will be specifically outlined. They can thus easily be included in current pipelines for consortia establishment in many biotechnological processes including wastewater degradation/ conversion and bioremediation.

The mechanisms underlying co-adaption may very well also be responsible for interspecies interactions that stabilise complex communities, found ubiquitously in natural man-made environments, and common causes of chronic infections. The mechanistic insight generated in the present proposal will identify promising targets for strategies aiming to improve treatment and application of multispecies biofilms.