Disappearance of docosahexaenoic and eicosapentaenoic acids from cultures of mixed ruminal microorganisms.

  title={Disappearance of docosahexaenoic and eicosapentaenoic acids from cultures of mixed ruminal microorganisms.},
  author={Amer A. AbuGhazaleh and Thomas C. Jenkins},
  journal={Journal of dairy science},
  volume={87 3},
Previous studies showed conflicting results regarding the ability of ruminal microorganisms to hydrogenate docosahexaenoic acid (C22:6, DHA) and eicosapentaenoic acid (C20:5, EPA). To determine the disappearance of DHA and EPA from mixed ruminal cultures, 2 ruminal in vitro experiments were conducted using graded levels of DHA and EPA. The first experiment examined DHA added at 0, 5, 10, 15, and 20 mg per culture flask. In the second experiment, EPA was added at 0, 5, 10, and 15 mg per culture… 

Biohydrogenation of Docosahexaenoic Acid

Pathways of docosahexaenoic (DHA) biohydrogenation are not known; however, DHA is metabolized by ruminal microorganisms. The addition of DHA to the rumen alters the fatty acid profile of the rumen

In vitro ruminal biohydrogenation of eicosapentaenoic (EPA), docosapentaenoic (DPA), and docosahexaenoic acid (DHA) in cows and ewes: Intermediate metabolites and pathways.

Results from DPA incubations provided the first indication that the metabolism of this very long chain PUFA may involve the formation of conjugated double bond structures, and was speculated to have some relationship with the susceptibility of dairy sheep to marine lipid-induced milk fat depression.

Effect of in vitro docosahexaenoic acid supplementation to marine algae-adapted and unadapted rumen inoculum on the biohydrogenation of unsaturated fatty acids in freeze-dried grass.

Hydrogenation of trans-11, cis-15-18:2 occurred in the absence of in vitro DHA only, whereas substantial hydrogenation oftrans-11-18-1 to 18:0 only took place in incubations without DHA and with unadapted rumen inoculum, confirming the higher sensitivity of the latter process to DHA.

Reduction of the biohydrogenation of linoleic and alpha-linolenic acid by addition of different proportions of eicosapentaenoic acid and docosahexaenoic acid

The effect of adding docosahexaenoic (DHA) and eicosapentaenoic acid (EPA) on the in vitro biohydrogenation of linoleic (ALi) and alpha-linolenic acid (ALn) using ruminal fluid was evaluated. To 500

Docosahexaenoic acid elevates trans-18:1 isomers but is not directly converted into trans-18:1 isomers in ruminal batch cultures.

Two in vitro studies showed that trans-18:1 fatty acids are not produced from DHA, supporting that DHA elevates trans- 18:1 by modifying biohydrogenation pathways of other polyunsaturated fatty acids.

Short communication: docosahexaenoic acid promotes vaccenic acid accumulation in mixed ruminal cultures when incubated with linoleic acid.

Data suggest that DHA is the component in fish oil that promotes VA accumulation when incubated with linoleic acid, which would suggest that fish oil is the only source of omega-3 fatty acids suitable for human consumption.

Identification of C18 Intermediates Formed During Stearidonic Acid Biohydrogenation by Rumen Microorganisms In Vitro

The intermediates accumulated in the fermentation media after 72 h of incubation of 18:4n-3 suggest that similar to the biohydrogenation pathways of linoleic and α-linolenic acids, the pathway of the 18:2n-6 also proceeds with the formation of conjugate fatty acids followed by hydrogenation, although no conjugated dienes were found.

Short communication: Eicosatrienoic acid and docosatrienoic acid do not promote vaccenic acid accumulation in mixed ruminal cultures.

The data suggest that C20:3n-3 and C22:3 n-3 are not the active components in fish oil that promote VA accumulation when incubated with linoleic acid.

Influence of docosahexaenoic acid on the concentration of fatty acids and volatile fatty acids in rumen fluid analysed by a rumen-simulation techniques.

Changes in the composition and content of fatty acids (FA), including volatile fatty acids (VFA), in rumen fl uid were analysed by a rumen-simulation technique (RUSITEC) following dietary



Incorporation of n−3 fatty acids of fish oil into tissue and serum lipids of ruminants

In the total PL of muscle, the incorporated 20∶5 and 22∶6 substituted primarily for oleic and linoleic acid, and there was no consistent change in the porportion of arachidonic (20∶4) acid.

Isomerization of stable isotopically labeled elaidic acid to cis and trans monoenes by ruminal microbes Published, JLR Papers in Press, September 1, 2002. DOI 10.1194/jlr.M200284-JLR200

Trans fatty acids exposed to active ruminal cultures are converted to stearic acid but also undergo enzymic isomerization yielding a multitude of positional and geometric isomers.

Biohydrogenation and digestion of long chain fatty acids in steers fed on different sources of lipid

Feeding different sources of lipid with different fatty acid composition had significant effects on rumen function and the C20 PUFA in fish oil were biohydrogenated to a large extent.

Dietary marine algae (Schizochytrium sp.) increases concentrations of conjugated linoleic, docosahexaenoic and transvaccenic acids in milk of dairy cows.

Milk fat can be modified through nutritional management of dairy cows to provide more favorable fatty acids for consumers through nutritional manipulation of diets for dairy cows.

Influence of dietary fish oil on conjugated linoleic acid and other fatty acids in milk fat from lactating dairy cows.

Fish oil supplementation to diets of dairy cows increased the conjugated linoleic acid, transvaccenic acid, and n-3 fatty acids in milk.

Effects of ruminal or postruminal fish oil supplementation on intake and digestion in dairy cows.

The particular action of fish oil on ruminal digestion when compared to other lipid sources was demonstrated and showed a high degree of hydrogenation of 20- and 22-carbon fatty acids in the duodenum.

Evaluating acid and base catalysts in the methylation of milk and rumen fatty acids with special emphasis on conjugated dienes and total trans fatty acids

No single method or combination of methods could adequately prepare FAME from all lipid classes in milk or rumen lipids, and not affect the conjugated dienes.