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Pyruvate fermentation by Clostridium acetobutylicum
R Janati-Idrissi1, A M Junelles, A el Kanouni
1Laboratoire de chimie biologique 1, Université de Nancy 1, Vandoeuvre les Nancy, France.
Biochemistry and Cell Biology = Biochimie Et Biologie Cellulaire
|October 1, 1989
Summary
Clostridium acetobutylicum fermentation with pyruvate primarily yields acetate and butyrate. Pyruvate appears to repress solvent production, indicated by lower acetoacetate decarboxylase activity.
Area of Science:
- Microbiology
- Biochemistry
- Industrial Biotechnology
Background:
- Clostridium acetobutylicum is a key microorganism for producing solvents and organic acids.
- Understanding fermentation pathways is crucial for optimizing industrial bioprocesses.
Purpose of the Study:
- To investigate the fermentation end products of Clostridium acetobutylicum ATCC 824 when using pyruvate as the sole carbon source.
- To compare enzyme activities related to acid and solvent formation between cells grown on pyruvate and glucose.
Main Methods:
- Cultivation of Clostridium acetobutylicum ATCC 824 with pyruvate as the sole carbon source.
- Analysis of fermentation end products (acetate, butyrate).
- Enzyme activity assays for acetate kinase, butyrate kinase, acetoacetate decarboxylase, and glyceraldehyde-3-phosphate dehydrogenase.
Main Results:
- Pyruvate-grown cells predominantly produced acetate and butyrate.
- Acetate and butyrate kinase activities were elevated in pyruvate-grown cells compared to glucose-grown cells.
- Acetoacetate decarboxylase activity, crucial for solventogenesis, was lower in pyruvate-grown cells.
- Glyceraldehyde-3-phosphate dehydrogenase activity remained similar across both growth conditions.
Conclusions:
- Pyruvate metabolism in Clostridium acetobutylicum favors acid production (acetate and butyrate) over solvent production.
- Pyruvate appears to play a role in repressing the onset of solventogenesis, likely by downregulating key enzymes like acetoacetate decarboxylase.