Marine biofilm formation dynamics – from sensor development to fieldapplications
In this thesis, an optical fiber-based biofilm sensor has been developed in order to dynamically detect biofilm formation of bacteria and unicellular microorganisms in their natural marine environment. The device is based on the detection of natural fluorescence utilizing the intrinsic amino acid tryptophan of microorganisms constituting the biofilm. Promising sensor head geometries were modeled and optimized in terms of the spatial arrangement of the entire optical system and of the light emission and collection characteristics. In field experiments, biofilm formation dynamics has been quasi-continuously monitored by exposing the sensor to Baltic Sea and Pacific Ocean waters over a period of several weeks.