Biomimetic Dyes in Biotechnology

Abstract

Downstream processing refers to all the technologies that are responsible for the production of pure products after fermentation. Therefore, if one were to produce, for example, a protein, one would start with an appropriate bio-reactor containing native or engineered cells. The first step would be to separate the cells from the broth; if the product is an intra-cellular one, one would subsequently disrupt the cells to release the intra-cellular products and then embark on a clarification process to obtain a clear extract containing the protein of interest. The next step is to apply a whole series of high resolution purification techniques, particularly chromatographic steps, prior to subsequently ending up with pure protein. Therefore, downstream processing entails the execution of primary recovery stages followed by a series of high-resolution steps where we add value to the final product and then hopefully end up with pure homogeneous protein. Special interest is focused in this report on the high resolution stages of the process leading to pure product and particularly those steps involving the most refined version of chromatography, affinity chromatography (1). The technique of affinity chromatography exploits small ligands which bind specifically and reversibly to the protein of interest. The appropriate small ligand is covalently attached to a suitable solid support matrix in such a way that we can establish that as a column.