Start of funding 01.07.2005

Making the dynamics visible: Microorganisms as biocompatible indicators for fluid mechanics and high pressure processes

Peter Ferstl
Technische Universität München
Lehrstuhl für Fluidmechanik und Prozessautomation

Dr.-Ing. Hannes Petermeier
Technische Universität München
Lehrstuhl für Fluidmechanik und Prozessautomation

Prof. Dr. Douglas Bartlett
University of California, San Diego
Scripps Institution of Oceanography



The goal of the proposed research and cooperation is the preliminary study to vizualize both the process inhomogenities during high pressure treatment of food and the analysis of flow fields generated by microorganisms, e. g. Peritrich Ciliates.

High pressure treatment of food was regarded as a homogenous process for many years, but recent studies indicate that this is not the case. Thus, instabilities which occur during the high pressure treatment of food must be studied thoroughly to ensure a safe and valuable product. On the other hand, the development of a qualitative imaging technique to study flow fields caused by microorganisms showed that biocompatibility is of vital importance, as the introduction of any foreign object into the system altered bacterial behavior. These findings indicate an important need to develop a method to conduct PIV measurements on the flow field using techniques compatible to both process inhomogenities and microorganisms. The proposed method includes the use of fluorescent and bioluminescent microorganisms as tracers and indicator particles, respectively.

This technique provides a twofold benefit; First, the microorganisms themselves act as biological tracers in the flow field, which eliminates the need to introduce foreign particles into the system and disrupt the natural behavior of the organisms; Second, the use of microorganisms also allows for the determination of their behavior under high pressure treatment.