Abstract
Extracellular proteins produced by yeast have been observed to stratify in the extracellular fluid of a batch bioreactor, thus creating a vertical concentration gradient. We observed that, in the four different experiments conducted, each varied in their protein recovery characteristics. For example, sparging the system with gas accentuates the separation, though even in a nonsparged system, thein situ generation of minute carbon dioxide bubbles by yeast cells creates a protein gradient as the bubbles carry proteins upward. Based on these and other observations, we propose possible strategies for recovering the individual proteins from a system containing the four major proteins considered. A simple steady-state mathematical model, based on convective upward protein transport being balanced by downward protein diffusion, has been used to describe the behavior of each of these four extracellular proteins in the fermentation broth.
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Abbreviations
- Cb :
-
protein concentration at the bottom of the fermentor
- CL :
-
liquid concentration of an individual protein, mg/cm3
- Cm :
-
protein concentration at the middle of the fermentor
- Ct :
-
protein concentration at the top of the fermentor
- D:
-
protein dispersion coefficient, cm2/s; k, 3QK/Dr (πR2), cm−1
- kH:
-
separation efficiency factor
- K:
-
proportionality (equilibrium) constant, F/Cl, cm
- SR:
-
separation ratio, Ct/Cb
- Q:
-
gas flow rate, cm3/s
- X:
-
dimensionless protein concentration at position z
- Xm :
-
dimensionless concentration at the fermentor midpoint (at z=H/2)
- z:
-
column vertical position, cm (0<z<H), where z = 0 is the base position and z=H is the top of the fermentation broth Γ, bubble protein concentration, mg/cm2
- r:
-
radius of bubble, cm
- R:
-
radius of column, cm.
Reference
Charm, S. E., Morningstar, J., Matteo, C. C., and Paltiel, B. (1966),Analytical Biochemistry 15, 498–508.
Park, D. H., Baker, D. S., Brown, K. G., Tanner, R. D., and Malaney, G. W.(1985),J. Biotechnology 2, 337–346.
Effler, W. T., Jr., Pandey, N. K., Tanner, R. D., and Malaney, G. W. (1986),Biotechnology and Bioengineering Symposium No. 17, Scott, C., ed., Wiley, New York, pp. 633–643.
Effler, W. T., Tanner, R. D., and Malaney, G.W. (1989),Bioproducts and Bioprocesses, Fiechter, A., Okada, H., and Tanner, R. D. eds., Springer-Verlag, Berlin, FRG, pp. 235–256.
Potter, F. J., Wilson, D. J., and Tanner, R. D. (1988),8th International Biotechnology Symposium, Paris, France.
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DeSouza, A.H.G., Wilson, D.J. & Tanner, R.D. In situ bubble fractionation strategies for separating individual proteins in a batch baker’s yeast fermentation process. Appl Biochem Biotechnol 24, 565–578 (1990). https://doi.org/10.1007/BF02920279
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DOI: https://doi.org/10.1007/BF02920279