Biofilm organisms are embedded in a matrix of extracellular polymeric substances (EPS) in which they lead their life. From their point of view, this matrix has paramount advantages. It allows them to stay together for extended periods and form synergistic microconsortia. It retains extracellular enzymes and turns the matrix into an external digestion system and a universal recycling yard. The EPS matrix protects its microorganisms against desiccation, it allows for intense communication and represents a huge genetic archive. Microorganisms can remodel their matrix, break free and eventually, they can use it as a nutrient source. The EPS matrix can be considered as one of the emergent properties of biofilms and is a major reason for the success of this form of life.
Nevertheless, the EPS have been termed the "black matter of biofilms" by good reasons. First of all: the isolation methods define the results. In most cases, only water soluble EPS components are investigated; insoluble ones such as cellulose or amyloids are much less included. In particular in environmental biofilms with many species, it is difficult to isolate and separate the various EPS molecules they are encased in and to define which species produced which EPS. The regulation and the factors which trigger or inhibit EPS production are still very poorly understood.
Furthermore, bacteria are not the only microorganisms to produce EPS. Archaea, Fungi and algae can also form EPS. What is their composition, function, dynamics and regulation? What do they all have in common?
In this conference, the latest state of knowledge will be presented and all aspects of the EPS matrix - from the ecological, health and antifouling perspectives - will be brought together in order to expand our understanding of the functions, properties and characteristics of the matrix as well as the possibilities to strengthen or weaken it.