Biomass separation vacuum filtration

Traditionally, the cellular biomass is separated by centrifugation. Ammonium sulfate is then added to the supernatant to precipitate the protein product from the media. This is followed by further centrifugation and dialysis to remove the residual ammonium sulfate from the protein product. Cross-flow filtration (CFF) can replace all of these steps with a significant improvement in recovery and yield. Indeed, CFF appears to offer many advantages over conventional separation processes like centrifugation, vacuum filtration and precipitation/dialysis for this application. 

Most filtration processes used in large-scale biotechnology should not have the potential to generate microbial aerosols. Filtration columns normally use gravitational forces to separate products from impurities and so are low energy processes. The only potential problem can come in either rotary vacuum filtration or with filter presses if a violent method of biomass removal from the filter is used. Wickramanayake has reported that it is often the practice with filter presses to knock the cell mat of the filter with hammers. This practice has been shown to generate microbial aerosols. 

---