Institute of Technical Biochemistry, University of Stuttgart, Allmandring, Germany. michael.knoll@itb.uni-stuttgart.de|Institute of Technical Biochemistry, University of Stuttgart, Allmandring, Germany. michael.knoll@itb.uni-stuttgart.de|Institute of Technical Biochemistry, University of Stuttgart, Allmandring, Germany. michael.knoll@itb.uni-stuttgart.de|Institute of Technical Biochemistry, University of Stuttgart, Allmandring, Germany. michael.knoll@itb.uni-stuttgart.de|Institute of Technical Biochemistry, University of Stuttgart, Allmandring, Germany. michael.knoll@itb.uni-stuttgart.de