Biomass separation centrifugation

The organic phase was separated from the aqueous phase containing biomass by centrifugation. Epoxide products were recovered from the organic phase by vacuum distillation. 

Biomass separation of insoluble from soluble material, with either phase being retained depending on the location of the product as intracellular or extracellular material. Examples of unit operations commonly used include centrifugation, filtration, and sedimentation. 

The final system, shown in Figure 30.4D, is the continuous system with a partial (PRF) or complete (RF) cell recycle. It is similar to the continuous system, but cells are returned to the fermentor by means of a biomass separation device. Cross-filtration units, centrifuges, and settling tanks have all been used for biomass separation.22 In the partial cell recycle fermentor, a steady state is achieved as in the continuous system. This process is typically used to increase the productivity of the system and is used commonly in wastewater treatment and ethanol production type applications. 

By removing biomass by centrifugation and selectively extracting the acid from the organic solvent with a saturated solution of NaHCOs, recovery of the unreacted flurbiprofen and its separation from the ester were easily accomplished. 

The most widely available yeast biomass is a by-product of the brewing industry, where the multiplication of yeast during brewing results in a surplus of ceUs. Eor every barrel (117 L) of beer brewed, 0.2—0.3 kg of yeast soHds may be recovered. In the U.S., a substantial fraction is recovered and made available about 40 x 10 kg of brewers yeast aimually. The yeast is recovered from beer by centrifuging and dried on roUer dmms or spray dryers and sold as animal feed or a pet-food supplement. It can be debittered by alkaline extraction to remove the bitter hop residues, and is then sold mainly by the health-food industry. It is available as tablets, powder, or flakes and is often fortified with additional vitamins. Distillers yeast caimot be readily separated from the fermented mash and the mixture is sold as an animal feed supplement. 

Recovery. Citric acid fermentation broth is generally separated from the biomass using filtration or centrifugation. The citric acid is usually... 

Production of the color involves centrifugal separation of the biomass, cell breakage, and extraction. Use of a salt solution rather than water as an extraction medium increases stability of the color during extraction. Methods for partial exclusion of the polysaccharide from the color extract in order to enhance resolubilization of the dried color were developed. These processes include either microfiltration or co-precipitation of the polysaccharide with an added positively charged polysaccha-... 

The classical way to determine biomass concentration is typically an off-line method, namely to harvest a known aliquot of the culture suspension, separate cells by centrifugation, wash the cells and dry them to constant weight at a few degrees above the boiling point of the solvent (i.e. aqueous medium, usually... 

Off-line determination of biomass concentration by classical gravimetric methods requires cell separation, washing steps and drying to constant weight. The separation of cells can be made either by centrifugation or by filtration. 

Yeast separation and concentration. Extraction of ethanol from biomass requires several separation steps, traditionally by centrifuging, sedimentation and cake filtration. First, after the fermentation, the yeast is removed from the fermentation broth and may be recycled. Additionally, after ethanol is stripped from the fermentation broth by steam followed by the removal of solid fractions, the remaining material called the thin stillage can be clarified for reuse upstream as the process water. 

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. 

The majority of microbial enzymes are produced in relatively small batch fermenters. After separation from the biomass with open membranes, filter presses, or centrifuges, UF is used to concentrate the enzyme and remove small peptides, oligosaccharides and salts. 

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