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Glucose metabolism by Lactobacillus divergens
I N De Bruyn1, W H Holzapfel, L Visser
1Department of Microbiology, University of Pretoria, Republic of South Africa.
Journal of General Microbiology
|August 1, 1988
Summary
Lactobacillus divergens ferments glucose via glycolysis, producing primarily lactate. This study confirms Lactobacillus divergens as a homofermentative organism, with minor fermentation products derived from other sources.
Area of Science:
- Microbiology
- Biochemistry
- Metabolic pathways
Background:
- Lactobacillus divergens was previously suggested to be homofermentative based on lactate being the major fermentation product.
- Previous studies utilized D-[1-14C]- and D-[3,4-14C]glucose, indicating glycolysis as the likely pathway.
Purpose of the Study:
- To conclusively determine the fermentation pathway of glucose by Lactobacillus divergens.
- To confirm the homofermentative classification of L. divergens using detailed metabolic analysis.
Main Methods:
- Fermentation of D-[1-14C]-, D-[2-14C]-, and D-[3,4-14C]glucose by L. divergens.
- Isolation and analysis of fermentation products.
- Determination of specific radioactivities and carbon-atom distribution patterns.
Main Results:
- Positional labeling patterns and specific radioactivities confirmed glucose degradation via the glycolytic pathway.
- Lactate was the predominant product, with minor amounts of acetate, formate, and CO2 from pyruvate.
- D-[U-14C]glucose experiments showed ~75% of lactate derived from glucose, while formate and acetate were <10% glucose-derived.
Conclusions:
- Lactobacillus divergens is definitively a homofermentative organism.
- Glucose is primarily metabolized through glycolysis.
- Secondary fermentation products originate from pyruvate and potentially non-glucose endogenous sources.