centrifugal separations in biotechnology

[...]... Vibrating screen filter J siphOnbasket L pusherJ washing ,) | J r _~ Invertingbag 1 basket ~ Tumbling screen I _('Wide-angle Figure screen j 1.8 Batch and continuous filtering centrifuge classification 10 Centrifugal Separations in Biotechnology feed suspension or 'charge' and perform various cycles to process the suspension, including filtering, washing, deliquoring/dewatering with or without drying,... (cross-contamination of product protein) and finer debris which renders the separation problem more difficult, resulting in increased suspended solids loading up the depth filter As a minimum, cell viability of mammalian cell lines should be maintained at a high level when making separation using production centrifuges This will be discussed in detail in later chapters In subsequent chapters, the principle... Dewatering of fine-particle slurries, Minerals and Metallurgical Processing, vol 19, issue 1, pp 1-8, February 2002 Introduction 17 Problems (1.1) Can you engineer protein to be expressed reliably in intracellular contents of the cells in the form of soluble substance instead of in inclusion bodies (solid) using E coli or Bacillus subtilis? (1.2) Assuming you can successfully express protein in intracellular... Various 12 CentrifugalSeparationsin Biotechnology recombinant proteins are commonly expressed through an engineering culture such as yeast, bacteria (e.g.E coli), and living cells (e.g mammalian and plant cells) The extracellular (exterior of cells) protein expressed by yeast and mammalian cells are in the liquid phase, while protein expressed by the engineered bacteria is inside the bacteria (i.e intracellular),... for various duties 6 Centrifugal Separations in Biotechnology With reference to the middle bioprocess in Figure 1.4, the protein is expressed intracellular in the bacteria After harvesting and homogenizing, the protein is released from the lysed bacteria in the inclusion bodies that need to be isolated before additional downstream processing Centrifugation is used to sediment the inclusion bodies while... drying, unloading and decelerating (for peeler) or decelerating and unloading (for regular baskets), and cleaning Pusher, conical screen, and screenbowl are continuous centrifuges Feed is continuously introduced into these centrifuges and cake retained by the filter media is continuously being removed Filtrate liquid, with minimal suspended solids, is also removed separately Suspension containing biological... figures visit: http://books.elsevier.com/companions/9781856174770 1 Introduction 1.1 Introduction Biotechnology has revolutionized our life in the twentieth century 1 Its impact is only now being felt from engineering food 2,3, engineering and delivering drugs 4,5,6, to engineering consumable products Without doubt it will continue to influence our daily lives for years to come One of the many successful... using an ultrafiltration and diafiltration combination The end-product is a concentrated protein solution in a suitable buffer liquid At this stage, the protein can be purified using ion-exchange or affinity chromatography to remove any impurities and contaminants A final sterile filtration involves the use of a 0.2-micron size microfilter to remove bacteria that are incurred during processing The final... suspended solids in centrate or solid recovery, throughput or capacity, and cell viability 14 Centrifugal Separations in Biotechnology 1.7.1 Protein Yield For a soluble protein expressed from extracellular process, one important measure of the separation performance of the centrifuge is the protein yield Y Yield is defined as the ratio of the amount (e.g kg/min or gm/min) of protein recovered in the liquid... dynamics in a rotating frame (such as a rotating bowl) is highly non-intuitive compared to the same occurring in a nonrotating reference frame In this chapter, we will first present some nonintuitive phenomena such as Coriolis effect 1 and quadratic pressure behavior; this is followed by discussion of more intuitive key mechanisms such as centrifugal force and Stokes' law in sedimentation 2.2 2.2.1 Non-intuitive . impact is only now being felt from engineering food 2,3, engineer- ing and delivering drugs 4,5,6, to engineering consumable products. Without doubt it will continue to influence our daily lives. screening, pilot testing, clinical manufacturing testing, full- scale production, and for small-scale testing in the laboratory to investigate alternatives and improvements to the existing process. alt="" Centrifugal Separations in Biotechnology Prelims-9781856174770.qxd 6/14/07 5:38 PM Page i In God, I Trust Prelims-9781856174770.qxd 6/14/07 5:38 PM Page ii Centrifugal Separations in Biotechnology Wallace