Extracellular enzyme loss during polyelectrolyte flocculation of cells from fermentation broth
| Autor: | Carrie R. Pearson, Mark S. Gebert, Meng Heng, Charles E. Glatz |
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| Rok vydání: | 2004 |
| Předmět: |
Flocculation
Protein Denaturation Chromatography Chemistry Subtilisin Bioengineering Bacillus Hydrogen-Ion Concentration Applied Microbiology and Biotechnology Polyelectrolytes Polyelectrolyte Bacterial Proteins Nephelometry and Turbidimetry Fermentation Extracellular Polyamines Titration Denaturation (biochemistry) Centrifugation Biotechnology |
| Zdroj: | Biotechnology and bioengineering. 87(1) |
| ISSN: | 0006-3592 |
| Popis: | Association of extracellular protein product with flocculated cells reduces product yield. Here, partitioning of the enzyme subtilisin between the liquid and polyelectrolyte-flocculated and sedimented Bacillus increased as the polymer dosage was increased beyond that necessary to obtain optimum floc character (brain floc) for cell removal by centrifugation. Partitioning to the cell floc is partly physical entrapment at all polymer dosages; however, at higher levels there is also direct interaction between the polyelectrolyte and enzyme. Enzyme loss was not likely due to pH denaturation during the flocculation process because conditions were within the stable pH range of the enzyme. The direct interaction between polyelectrolyte and enzyme was characterized through turbidimetric titrations and partitioning studies. Neither changes in the polymer feed concentration nor the method of polymer addition reduced the enzyme loss at dosages optimal for cell removal. |
| Databáze: | OpenAIRE |
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