Microfiltration for Removal of Microorganisms or Cell Debris

In recent years there has been a significant interest in the use of microorganism-based fermentations for the production of many specialty chemicals.  

The product of interest may be produced by either an extracellular or intracellular process relative to the microorganisms. In either of these situations, one of the key steps is the efficient removal of microorganisms or cell debris fi om the fermentation broth. In biotechnology terminology, this step, where cells are separated from the soluble components of the broth, is described as cell harvesting. 

The processing steps differ depending on the location of the product relative to the microorganisms. For extracellular products, maximizing broth recovery by clarification is important since the product is in solution. When the product is located within the cell walls, concentration of cell mass is required followed by cell rupture and recovery of products from the cell debris. 

Final concentrations up to 100 gm (dry wt.)/L or cell densities up to 10 cells/L can be achieved by cross-flow filtration with diafiltration.l lf lt5 ] 

A concentration of organisms expressed In wet wt% concentration of organisms expressed in dry g/L 

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