[42] Preparation and colorimetric determination of lactic acid

Barker, S. B.

doi:10.1016/s0076-6879(57)03382-0

Cited by 84 publications

(25 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…At levels higher than 10-3 M, ATP inhibits glycolysis in the reconstructed system. In addition, Na+, HP04, or Tris', each at a concentration of 0.3 M, inhibits lactate production from glucose in this system (Table II) In the reconstructed hemolysate system, the pH optimum for glycolysis was again 8.1, and the expected 1: 2 stoichiometry was observed between glucose disappearance and lactate production, When the results in Table I (2) 3-phosphoglycerate The occurrence of 2,3-diphosphoglyceric mutase (Reaction 3) interferes with the assay for phosphoglyceric kinase, since it removes 1,3-diphosphoglycerate. The side reaction can be repressed, however, by the addition of excess 2,3-diphosphoglycerate, which has been shown to be an inhibitor of the reaction (39).…”

mentioning

confidence: 75%

Erythrocyte Metabolism. V. Levels of Glycolytic Enzymes and Regulation of Glycolysis*

Chapman¹,

Hennessey²,

Waltersdorph³

et al. 1962

J. Clin. Invest.

136

View full text Add to dashboard Cite

mentioning

confidence: 75%

Erythrocyte Metabolism. V. Levels of Glycolytic Enzymes and Regulation of Glycolysis*

Chapman¹,

Hennessey²,

Waltersdorph³

et al. 1962

J. Clin. Invest.

136

View full text Add to dashboard Cite

“…Volatile fatty acids were steam-distilled from the acidified medium after removal of cells (Friedemann, 1938) and analysed qualitatively by paper chromatography (Elsden & Lewis, 1953) or quantitatively by chromatography on celite columns (Bueding & Yale, 1951). Lactic acid and formic acid were determined colorimetrically (Barker & Summerson, 1941 ;Grant, 1947) and succinic acid by a manometric method (Umbreit, Burris & Stauffer, 1957).…”

Section: )mentioning

confidence: 99%

“…A number of glycerol-containing media were used in an endeavour to isolate not only strictly anaerobic rumen bacteria, but also facultative anaerobes and bacteria which do not need the exacting conditions of P. N. HOBSON AND S. 0. M~N N some rumen bacteria (see review by Bryant, 1959). Acetate was included in some of the media in an attempt to isolate bacteria which fermented glycerol and acetate to butyric acid (compare Clostridium tyrobutyricum) since the experiments with whole rumen contents suggested that propionic acid was not the only end product of glycerol fermentation in the rumen as suggested by Johns (1953), and acetate is a normal constituent of rumen fluid.…”

Section: Introductionmentioning

confidence: 99%

The Isolation of Glycerol-Fermenting and Lipolytic Bacteria from the Rumen of the Sheep

Hobson¹,

Mann²

1961

Journal of General Microbiology

130

View full text Add to dashboard Cite

SUMMARYFacultatively anaerobic bacteria appear to play little part in glycerol fermentation in the sheep rumen. Amongst the most important members of the glycerol-fermenting flora are strict anaerobes of the group Selenomonas ruminantium var. lactilyticas. Three isolates of a different group of strictly anaerobic curved Gram-negative rods, which hydrolyse linseed oil and tributyrin as well as fermenting glycerol, were obtained in numbers which suggest they are amongst the more important lipolytic bacteria in the rumen. The main product of fermentation of glycerol by the selenomonads and the lipolytic bacteria is propionic acid, but other acids are also formed. The properties of these bacteria and some others isolated during the experiments are described, All the bacteria appear to be normal inhabitants of the rumen of sheep fed a number of different rations. The numbers of these organisms were not appreciably increased by feeding glycerol or triglycerides to the animals.

show abstract

“…The column was eluted with benzene containing 25% butanol and the effluent was collected in 5-ml fractions. The peak of lactic acid, detected by measuring the radioactivity with a portion of each fraction, was pooled and its specific radioactivity was determined by assaying its amount according to the method of BARKER (13).…”

Section: Animalsmentioning

confidence: 99%

Role of Lactate as an Intermediate of Fatty Acid Fermentation in the Sheep Rumen

Nakamura

Takahashi

1971

J. Gen. Appl. Microbiol.

View full text Add to dashboard Cite

Fresh rumen contents of sheep, taken at various periods after feeding, were incubated with sodium DL-lactate [2-'4C] and the turnover rate of the acid was estimated. Th° radioactivities of consumed lactate were predominantly found in acetate in most cases, but also in propionate when the pool size of lactate was large. By comparing the rate of fatty acid production via lactate with the rate of individual fatty acid production determined simu;taneously, the contribution of lactate as an intermediate in fatty acid production was calculated. Under certain conditions, 40% of acetate and 32% of propionate were formed via lactate when the animal was fed on hay and concentrated feed.Lactate had been considered as an important intermediate of volatile fatty acid fermentation proceeding in the rumen, although it usually existed at a low level. For example, many bacterial strains isolated from the rumen produce a large amount of lactate from glucose as a final product (1) and the others can grow in a medium containing lactate as a single energy source. Lactate is converted to propionate by these strains through succinate (2) or acrylate (3). These findings are in agreement with the in vivo experiment which showed that lactate introduced into the rumen in a large amount resulted in an increase in the molar ratio of propionate to total volatile fatty acids (4).JAYASURIYA and HUNGATE (5), on the other hand, measured the turnover rate of radioactive lactate with the bovine rumen ingesta in vitro. They concluded that the amount of substrate fermented via lactate was 13% of the total amount of substrate fermented in the rumen of a grain-fed animal. The value became 0.8% or less in a hay-fed animal. They also showed that radioactivities of consumed lactate were found mainly in acetate and less in propionate.Moreover, 41% of propionate produced in the bovine rumen, on the average, was proved to be formed via succinate (6). These findings led to the belief that the role of lactate as an intermediate of the rumen fermentation, especially as a precursor of propionate, is not significant (for example, 319

show abstract

[42] Preparation and colorimetric determination of lactic acid

Cited by 84 publications

References 3 publications

Erythrocyte Metabolism. V. Levels of Glycolytic Enzymes and Regulation of Glycolysis*

Erythrocyte Metabolism. V. Levels of Glycolytic Enzymes and Regulation of Glycolysis*

The Isolation of Glycerol-Fermenting and Lipolytic Bacteria from the Rumen of the Sheep

Role of Lactate as an Intermediate of Fatty Acid Fermentation in the Sheep Rumen

Contact Info

Product

Resources

About