Current challenges in the area of downstream processing of macromolecular bioproducts

The challenges in the area of downstream processing of molecular bioproducts are discussed. The downstream processing of economically interesting macromolecular bioproducts such as proteins are the most cost-intensive step of a bioprocess. The products to be purified belong to a quite heterogeneous class of substances which are often difficult to characterize, and the damage degree of purity is usually extraordinary. It has been shown that effective protein crystallization from impure product solutions is possible by imposing controlled nucleation via suitable seeding strategies.