Bacteria propionic acid

Laboratory-scale experiments which used L. casei symbiotically with Propionibacterium freudenreichii in the fermentation of whey gave an average yield of 2.2 mg of vitamin per liter the maximum was 4.3 mg/liter. Production of vitamin Bi2 is not species-specific. All species of Propionibacterium, when cultivated under the same conditions, produce active substances, but in different quantities. P freudenreichii and P zeae synthesized sufficient quantities to warrant their consideration for commercial exploitation. Because propionic acid bacteria are active during Swiss cheese ripening, it was anticipated, and actually demonstrated, that production of vitamin Bi2 in Swiss cheese is influenced by the same factors that influence its production in pure culture, particularly by the cobalt content of milk (Hargrove and Leviton 1955). 

Sewage wastes contain as much as 4 ppm of vitamin Bi2 (Hoover et al. 1952B Miner and Wolnak 1953). Although frowned on for aesthetic reasons as a source of vitamin Bi2 for human nutrition, wastes from activated sludge processes may well provide the cheapest source for preparation of vitamin Bi2 concentrates used in cattle feed. Symbiotic growth of lactic and acetic acid bacteria has been recommended for producing sour milk products biologically enriched with vitamin Bi2 (Rykshina 1961). Acetic acid bacteria cultured in whey fortified with cobalt salts led to an 80-fold increase in vitamin B12. Propionic acid bacteria in skim milk supplemented with dimethylbenzimidazole increased the vitamin content by 300-fold. 

Hettinga, D. H. and Reinbold, G. W. 1972A. The propionic-acid bacteria—A review. I. Growth. J. Milk Food TechnoL 35, 295-301. 

Leviton, A. and Hargrove, R. E. 1952. Microbiological synthesis of vitamin B[2 by propionic acid bacteria. IruL Eng. Chem. 44, 2651-2655. 

Winkler, S. 1953. Antibiotic activity of lactobacilli against propionic acid bacteria. 13th Int. Dairy Congr. Proc. 3, 1164-1167. (German)... 

The first use of isotopic labeling in the study of the citric acid cycle and one of the first in the history of biochemistry was carried out by Harland G. Wood and C. H. Werkman in 1941.ab The aim was to study the fermentation of glycerol by propionic acid bacteria, a process that was not obviously related to the citric acid cycle. Some succinate was also formed in... 

Propionic (propanoic) acid-producing bacteria are numerous in the digestive tract of ruminants. Within the rumen some bacteria digest cellulose to form glucose, which is then converted to lactate and other products. The propionic acid bacteria can convert either glucose or lactate into propionic and acetic acids which are absorbed into the bloodstream of the host. Usually some succinic acid is also formed. 

Using the same mechanism (Fig. 17-10), propionic acid bacteria are also able to ferment lactate, the product of fermentation by other bacteria, to propionate and acetate (Eq. 17-28). The net gain is one molecule of ATP. This reaction probably accounts for the niche... 

S.F. Carson and S. Ruben, C02 Assimilation by Propionic Acid Bacteria Studied by Use of radioactive Carbon, Proceedings of the National Academy of Sciences 26, 422-426, 1940. 

S.F. Carson, J.W. Foster, S. Ruben and H.A. Barker, Radioactive Carbon as an Indicator of Carbon Dioxide Reduction. V. Studies of Propionic Acid Bacteria. ... 

The assimilation of CO2 by bacteria was first demonstrated by Wood and Werkman who observed that during the fermentation of glycerol by propionic acid bacteria there was an over-all uptake of COj and that the amount of product (succinic acid) formed corresponded to the CO which was taken up. Since pyruvic acid was known to be present it was proposed that pyruvic acid condenses with CO to produce oxalacetic acid (Fig. 3, Wood-Werkman reaction) which is subsequently converted to succinic acid. 

The subsequent conversion of oxalacetate to succinate is believed to occur by way of malate and fumarate since Krebs and Eggleston have demonstrated that the following reactions occur reversibly in propionic acid bacteria. 

In accordance with these reactions it has been found that isotopic CO2 is assimilated by propionic acid bacteria to produce among other products, succinic acid containing isotopic carbon localized in the carboxyl groups. In general, it has been observed that those organisms which form succinic, propionic, or lactic acids are able to fix isotopic COj in the carboxyl positions. 

---