Production of acetic acid by immobilized whole cells ofClostridium thermoaceticum
Autor: | Daniel I. C. Wang, George Wang |
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Rok vydání: | 1983 |
Předmět: |
Bioengineering
Acetates Carrageenan Applied Microbiology and Biotechnology Biochemistry Matrix (chemical analysis) chemistry.chemical_compound Acetic acid Dry weight Molecular Biology Acetic Acid Clostridium Chromatography General Medicine Culture Media Dilution Kinetics chemistry Volume (thermodynamics) Fermentation Steady state (chemistry) Gels Biotechnology |
Zdroj: | Applied Biochemistry and Biotechnology. 8:491-503 |
ISSN: | 1559-0291 0273-2289 |
Popis: | Immobilized cells of Clostridium thermoaceticum for acetic acid production has been investigated. Using kappa-carrageenan gel as the immobilization-matrix, high cell concentration within the gel could be achieved and thus lead to high volumetric acetic acid productivity. Batch experiments using 3% gel showed that cell concentration up to 65 g (dry cell weight)/L gel could be achieved. These dry weight cell concentrations in the gel through immobilization are typically 10-15 times greater than what can be obtained in free-cell fermentations. The specific growth rate and acetic acid formation rate were similar to those observed for the free cells. Continuous culture experiments using a feed medium containing 20 g/L of glucose were performed where the reactor contained 50% by volume of the carrageenan gel and the pH was controlled at 6.9. Different steady states were acheived at dilution rates ranging from 0.061 to 0.399 h-1. Cells grew mainly near the surface of the gel and reached maximum concentration within the matrix of approximately 35 g/L. Dilution rates much greater than the maximum specific growth rate were obtained, which resulted in volumetric productivity up to 4.9 g/L-h. This value was significantly greater than that for the conventional continuous culture with free cells. Using a 40 g/L feed glucose concentration, steady states could be achieved between dilution rates of 0.12-0.4 h-1. The maximum productivity further increased to 6.9 g/L-h at a dilution rate of 0.37 h-1 and at an acetic acid concentration of 19 g/L. The cell concentration was 60 g (dry weight)/L gel at steady state. |
Databáze: | OpenAIRE |
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