Fermentation engineering, downstream processing of proteins and plasmid DNA as well as enzyme engineering and biocatalysis, respectively, are in the focus of research. The production of extracellular proteins by means of Gram negative bacteria is one of the main aims. For these purposes methods of genetic engineering, bioengineering and reaction engineering are applied. In addition, methods of pattern recognition are being developed in order to evaluate the state of cells from microscopic images without staining. Novel research areas are represented by the aerobic microbial degradation of oil and fat, the development of phototrophic processes as well as the generation of biogas.

Gram-negative and Gram-positive bacteria as well as different eukaryotes have been grown in submerse culture systems. These organisms include Escherichia coli, Klebsiella planticola, diverse Bacillus sp., Dictyostelium discoideum, and Euglena gracilis. Cultivation conditions and operating strategies have been optimized in order to obtain maximal concentrations of products like recombinant proteins, plasmid DNA or polysaccharides. Oxygen supply for aerobic cultivations by other means than by pressurised air has been studied as well as the degradation of oils and fats during aerobic cultivation of microorganisms. Biorefinery concepts are current research targets. The production of high-value materials in phototrophic cultivation systems like algae is in the focus of present research efforts. Residues thereof are offered to special microorganism communities in biogas processes.

Research targets in this area are the separation and purification of, primarily, recombinant proteins and plasmid-DNA, but also of special polysaccharides. Recombinant proteins include the whole range from industrial enzymes for use in biofuel processes to human transcription factors of interest in stem cell research. The main aim consists in achieving secretion of recombinant proteins into the extracellular space with Gram-negative bacteria. This is achieved by coexpressing bacteriocin release proteins which lead to rendering the outer membrane permeable. Different pseudo-affinity interactions are used for adsorptive as well as extractive downstream processes. Extraction processes are of particular interest even in the case of plasmid DNA separation. Plasmid DNA is processed for being applicable as vectors in gene therapy and genetic vaccination.

Multiphase reaction systems like those of the type liquid-liquid-solid have been studied in different reactors. Modelling of reactions with pH-shift in the presence of partitioning reactants in liquid-liquid two-phase systems was one of the main aims. Stereospecific synthetic reactions of aldolases as well as the enzymic synthesis of precursors have been studied extensively. Fluidized-bed reactors are still in the focus of research for the application of immobilized enzymes.

Methods of pattern recognition are applied in order to simultaneously count cells and analyse their state with respect to viability. This concept has successfully been applied for the analysis of yeast cultures on the basis of images from standard microscopes as well as from in situ-microscopes. The results have been successfully transferred to the analysis of submerse cultures of animal and human cell lines. Thus, the history of cell death by necrosis and apoptosis can be distinguished without cell staining. Microscopic images are obtained with darkfield illumination.