The Perfect Slime - Nature, Properties, Regulation and Dynamics of EPS

摘要

Biofilm organisms are embedded in a matrix of extracellular polymeric substances (EPS) in which they lead their life. 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.