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Glucose metabolism in Acetobacter aceti
Archives of Microbiology
|August 26, 1977
Summary
Acetobacter aceti cannot grow on glucose due to its inability to metabolize it effectively. Researchers found no pyruvate kinase activity, suggesting a key metabolic pathway is missing in this bacterium.
Area of Science:
- Microbiology
- Bacterial Metabolism
- Biochemistry
Background:
- Acetobacter aceti NCIB 8554 utilizes ethanol but not glucose as a carbon source.
- A glucose-sensitive mutant (A5) exhibits growth inhibition in the presence of glucose.
Purpose of the Study:
- To investigate the glucose metabolism pathways in wild-type and mutant Acetobacter aceti.
- To identify the metabolic bottlenecks preventing glucose utilization.
Main Methods:
- Radiorespirometric experiments with a custom-built continuous substrate feeding apparatus.
- Enzymatic assays to detect key metabolic enzymes.
- Glucose uptake experiments.
Main Results:
- Acetobacter aceti excretes approximately 30% of internalized glucose as gluconate and metabolizes 6% to CO2.
- The remaining glucose accumulates intracellularly without significant differences between wild-type and mutant strains.
- Pyruvate kinase activity (EC 2.7.1.40) was undetectable under various conditions.
Conclusions:
- The absence of detectable pyruvate kinase activity is a likely explanation for Acetobacter aceti's inability to grow on glucose.
- Glucose metabolism in Acetobacter aceti involves significant gluconate excretion and intracellular accumulation, rather than complete catabolism.