Developments in bioprocessing coming out of the University of Oulu led to the founding of BioSilta, which has developed a bacterial cell-cultivation technology based on a fed-batch method used in industrial processes. In EnBase™ any well of an MTP plate becomes a miniature bioreactor with a storage layer of starch-containing gel on the bottom and a liquid media layer containing an enzyme.
The enzyme acts as a pump that controls glucose release from the starch to the culture. This controlled nutrient-feeding technique provides much better conditions for bacterial cell culture, the company says, allowing up to 50 times the cell density and up to 10 times higher levels of recombinant protein compared to standard cultivation methods.
“EnBase allows you to scale down your research knowing that you can readily scale it up again,” explained CEO, Russell Golson. The product is available for a variety of formats: shake flasks, mini-shake flasks, starter tubes, and a range of deep well and standard MTP plates. A 24-well Opti-Set allows customers to try different glucose feeding concentrations alongside different media in a single-plate experiment.
“Cell culture conditions can be optimized in a short space of time,” added Golson. Applications of EnBase include increasing expression levels of recombinant proteins (with the University of Regensburg), achieving higher growth for B. subtilis (with the University of Greifswald), and increasing throughput on the Human Proteome Resource with collaborators at the Royal Institute of Technology in Sweden.
In another cell culture development, Peggy Stock, Ph.D., researcher in the molecular hepatology group at the University of Halle, described CellTech-BioReactor, a new system for biochemical monitoring. The project, funded by the state of Saxony-Anhalt, is being developed by the NEMO network, a consortium of small German companies and research facilities. The CellTech-BioReactor consists of a small disposable bioreactor allowing rapid assessment of the impact of compounds on hepatocytes in 3-D culture on various scaffolds.
A sandwich hybridization assay detects changes in liver enzyme (CYP) gene expression that could be related to compound toxicity. The system, at the prototype stage, is highly specific for CYP type, according to Dr. Stock, who hopes it can help replace animal systems.
Analysis of biomolecular interactions were also discussed. Markku Kulomaa, Ph.D., of the University of Tampere presented new types of avidins, a chicken-derived protein used widely as a probe in the study of biological macromolecules. Both avidin and its bacterial analogue, streptavidin, have been modified by mutagenesis for improved properties.
For instance, the avidin-biotin technology would benefit from avidins with multiple binding sites, said Dr. Kulomaa.
Temperature and organic solvent stable avidins have been created using an approach that compares amino acid sequences of avidin and similar proteins. A number of novel and multipurpose avidins are now being produced by this approach, some of which (the antidins) utilize ligands other than the well-known biotin.
Novamass, an ADMET specialist company, is now a member of Systems Biology Worldwide, a joint Finland-India venture addressing many aspects of early drug development. Novamass continues to develop its core competence in drug metabolism analysis, with a focus on metabolite identification.