Cell Debris Removal By Single-Use Diatomaceous Earth (DE) Filtration

Many biotechnological products are obtained by the help of native or recombinant microbial cells in fermentation processes. In order to get intracellular target molecules, like proteins or enzymes, the cells have to be destructed. This is done with cell rupture techniques (e.g. high-pressure homogenization) which generate a suspension containing cell debris and cell contents (proteins, DNA, mRNA, etc.). The first step in the following purification sequence is the removal of the cell debris. One possibility to do this is the usage of depth filters like the FILTRODISCTM BIO SD filter capsules from FILTROX. Often, a removal of cell debris is not possible by sole use of such filter capsules because of filter blocking.
Therefore they are usually used for so-called body-feed filtrations, in which a filter aid like diatomaceous earth is mixed with the unfiltrate to improve the filtrate flow by a decreased cake compressibility and an increased cake permeability. To enhance the separation further an additional precoat layer consisting of the filter aid could be applied.