Short Poster Lecture
Gallium is a strategically important metal for the German high-tech industry. It is used essentially in the semiconductor compounds GaAs, GaN or GaP for high-potential future technologies. This is offset by low recycling rates and declining availability on the world market. Therefore, the development of processes for the selective recovery of gallium from secondary raw material sources is a desirable starting point for dealing with the increasing scarcity of this resource on the world market. Particularly interesting is the development of a biotechnological method for selective biosorption by using the Phage Surface Display Technology.
This is a well-established method for the selection of highly specific peptide ligands in medicine and biotechnology. Random, short peptide sequences are presented on the surface according to genetically modified bacteriophages. In a biopanning called process, a pool of different bacteriophage is selected against a particular target, thereby enriching specific binding clone variants. A very effective method has been established for the selection of different phage display libraries. Gallium ions immobilized on a monolithic ion exchanger are made accessible for biopanning in an FPLC system. This chromatopanning allows the selective enrichment of gallium-binding clone variants under strictly controlled process conditions.
In the present study, we report about the enrichment, identification and characterization of several gallium-binding peptide motifs. Some promising gallium binding bacteriophage clones are chosen for further binding studies, including bacteriophage immobilization for real waste water treatment experiments.
The corresponding peptide sequences can be synthesized and used in subsequent experiments to characterize metal-peptide interactions and develop biosorptive materials for selective gallium recovery from industrial waste waters.