Biohydrogenation of Linolenic Acid to Stearic Acid by the Rumen Microbial Population Yields Multiple Intermediate Conjugated Diene Isomers

Lee, Yong-Jae; Jenkins, T.C.

doi:10.3945/jn.111.138396

Cited by 80 publications

(86 citation statements)

References 23 publications

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“…In ruminants, dietary vegetable and fish oils disappear in the rumen stomach compartment through lipolysis to free FA (fFA), followed by biohydrogenation of the released unsaturated FA (UFA) (Burns et al, 2003;Lee and Jenkins, 2011;Buccioni et al, 2012). In the rumen, dietary esterified lipids are hydrolyzed to fFA and glycerol as well as, in small concentrations, to mono-and diglycerides by microbial lipases; these lipases are extra-cellular enzymes assembled in small beads (Jenkins et al, 2008;Buccioni et al, 2012).…”

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confidence: 99%

Selenite and selenate affect the fatty acid profile in in vitro incubated ovine ruminal fluid containing linseed oil

Czauderna¹,

Kowalczyk²,

Marounek³

2013

CZECH J ANIM SCI

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ABSTRACT:The influence of selenite (Se IV ) or selenate (Se VI ) added to ovine ruminal fluid containing linseed oil (LO) on the profile of fatty acids (FA), particularly conjugated linoleic acid (CLA) isomers, was investigated. The ruminal fluid was incubated in vitro at 39°C under CO 2 either alone (the control fluid) or with LO (3.3 mg/ml) or with a combination of LO with either a low (0.167 μg/ml) or high (1.67 μg/ml) level of Se as Se IV or Se VI . LO added to ruminal fluids also provides an extra source of energy. The tubes with the examined fluids were removed after 0, 6, 12, 18, or 24 h of in vitro incubation and then analyzed to determine the FA levels. The lower and higher concentration of Se IV in the fluids with the LO revealed negligible effect on the concentration of the sum of the CLA isomers (∑CLA) in the fluid compared with the fluid with LO alone. The addition of a higher amount of Se IV to the fluid containing LO usually decreased the concentration of ∑CLA compared with the fluid containing the lower concentration of Se IV and LO. The concentration of c9t11c15C18:3 (cLNA) in the fluids with LO, irrespective of the presence of extra Se, increased throughout the incubations, although the addition of Se IV or Se VI to the fluids containing LO numerically reduced the increase of the concentration of cLNA compared with the fluid with LO alone. The concentration sum of the C18:1 isomers (ΣC18:1) in the control fluid numerically decreased throughout the incubations, while LO added to the fluid increased the concentration of ΣC18:1 throughout the incubations. LO added to the fluid, irrespective of the presence of Se IV or Se VI , significantly increased the concentration of ΣC18:1 compared with the control fluid and the fluids with Se IV or Se VI . The concentrations of C16:0 and C18:0 in the control fluid and the fluids containing Se IV or Se VI numerically increased throughout the incubations and were usually lower than in the fluids containing LO without or with Se IV or Se VI . The concentration of C18:3n-3 decreased throughout the incubation of the fluids containing LO, irrespective of the presence of Se IV or Se VI . LO added to the fluids, irrespective of the presence of Se IV or Se VI , increased the concentration of C18:2n-6 compared with the control fluid and the fluids with Se IV or Se VI . The higher concentration of Se IV or Se VI in the fluid with LO most efficiently increased the concentration of c5c8c11c14c17C20:5 compared with the control fluid or the fluids containing LO, irrespective of the presence of the lower concentration of Se IV or Se VI . LO added to the fluid, irrespective of the presence of Se IV or Se VI , increased the concentration of polyunsaturated FA compared with the control fluid or the fluids containing Se IV or Se VI .

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confidence: 99%

Selenite and selenate affect the fatty acid profile in in vitro incubated ovine ruminal fluid containing linseed oil

Czauderna¹,

Kowalczyk²,

Marounek³

2013

CZECH J ANIM SCI

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“…Among the many CLA isomers, c9t11 CLA has received the most attention because of its recognized health benefits as a cancer chemopreventive (Kennedy et al, 2010;Crumb 2011). The c9t11CLA is synthesized either in the rumen as an intermediate during the biohydrogenation of linoleic and linolenic acids (Harfoot and Hazlewood, 1987;Lee and Jenkins, 2011) AbstrAct: The effects of six essential oils (EO) on rumen fermentation and biohydrogenation were evaluated under in vitro conditions. Three doses (125, 250, and 500 mg/l) of EO were evaluated using in vitro 24 h batch culture of rumen fluid with a 55 : 45 forage : concentrate diet.…”

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confidence: 99%

Evaluating the effects of six essential oils on fermentation and biohydrogenation in in vitro rumen batch cultures

Günal¹,

Ishlak²,

AbuGhazaleh³

2013

CZECH J ANIM SCI

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Conjugated linoleic acids (CLA) have recently attracted significant attention because of their health benefits in a variety of models of metabolic and chronic inflammatory diseases. Among the many CLA isomers, c9t11 CLA has received the most attention because of its recognized health benefits as a cancer chemopreventive (Kennedy et al., 2010;Crumb 2011). The c9t11CLA is synthesized either in the rumen as an intermediate during the biohydrogenation of linoleic and linolenic acids (Harfoot and Hazlewood, 1987;Lee and Jenkins, 2011) AbstrAct: The effects of six essential oils (EO) on rumen fermentation and biohydrogenation were evaluated under in vitro conditions. Three doses (125, 250, and 500 mg/l) of EO were evaluated using in vitro 24 h batch culture of rumen fluid with a 55 : 45 forage : concentrate diet. Treatments were control (CON), control with Siberian fir needle oil (FNO), citronella oil (CTO), rosemary oil (RMO), sage oil (SAO), white thyme oil (WTO), and clove oil (CLO). Treatments were incubated in triplicate in 125 ml flasks containing 500 mg of finely ground total mixed ration (TMR), 25 mg of soybean oil, 10 ml of the strained ruminal fluid, 40 ml of media, and 2 ml of reducing solution. After 24 h, the pH was determined and samples were collected to analyze ammonia N, volatile fatty acids (VFA), and fatty acids (FA). Cultures pH was not affected by EO averaging 6.6 ± 0.2. In general, high EO doses reduced the total VFA concentration except for SAO and RMO. Relative to CON, all EO decreased (P < 0.05) ammonia N concentrations except for the highest dose of WTO. Except for SAO, EO did not modify acetate to propionate ratio. Relative to CON, the addition of CTO and FNO increased (P < 0.05) the proportions of isobutyrate and decreased (P < 0.05) the proportions of valerate and isovalerate. The concentrations (mg/culture) of C18:0 and C18:1 trans FA decreased (P < 0.05) with CTO, FNO, RMO, and SAO relative to CON. Most tested EO in this study had little to no effects on conjugated linoleic acids (CLA), and linoleic and linolenic acids concentrations. In conclusion, results from this study showed that except for effects on ammonia N, EO tested in this study had moderate effects on rumen fermentation. The reduction in the formation of trans FA and C18:0 with some EO may indicate shifts in the biohydrogenation pathways toward the formation of other unidentified intermediate FA. Keywords: plant extracts; volantile fatty acids; trans fatty acids; in vitroAbbreviations: CLA = conjugated linoleic acids; CLO = clove oil; CON = control; CTO = citronella oil; EO = essential oils; FA = fatty acids; FNO = Siberian fir needle oil; RMO = rosemary oil; SAO = sage oil; TMR = total mixed ration; VFA = volatile fatty acids; WTO = white thyme oil

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“…The 18:4n-3 biohydrogenation pathway in the rumen is still unknown, however, taking into account the recognized biohydrogenation pathways of 18:2n-6 and 18:3n-3 [36,37], the results herein obtained suggest that the 18:4n-3 pathway also involves the formation of conjugated fatty acids and hydrogenation of double bonds. The [37,[40][41][42][43]. Very recently, rumen incubation of 13 C labelled 18:3n-3 was described to produce fourteen 18:3 isomers, 5 nonconjugated 18:2 isomers and 8 CLA isomers, indicating that 18:3n-3 biohydrogenation pathways are more complex than those previously reported [42].…”

Section: Discussionmentioning

confidence: 93%

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

Alves

Maia

Bessa

et al. 2011

Lipids

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In vitro batch incubations were used to study the rumen biohydrogenation of unsaturated fatty acids. An earlier study using increasing supplementation levels of stearidonic acid (18:4n-3), revealed that the rumen microbial population extensively biohydrogenates 18:4n-3 after 72 h of in vitro incubation, though several intermediates formed were not completely characterized. Therefore, in the present study, samples were reanalyzed in order to identify the 18:2, 18:3 and 18:4 biohydrogenation intermediates of 18:4n-3. Gas-liquid chromatography coupled to mass spectrometry was used to characterize these intermediates. The acetonitrile chemical ionization mass spectrometry of the fatty acid methyl esters derivatives enabled the discrimination of fatty acids as non-conjugated or conjugated biohydrogenation intermediates. In addition, the acetonitrile covalent adduct chemical ionization tandem mass spectrometry yielded prominent ions indicative of the double bond position of the major 18:3 isomers, i.e. Δ5,11,15 18:3. Furthermore, the 4,4-dimethyloxazoline derivatives prepared from the fatty acid methyl esters enabled the structure of novel 18:2, 18:3 and 18:4 biohydrogenation intermediates to be elucidated. 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 (18:2n-6) and α-linolenic (18:3n-3) acids, the pathway of the 18:4n-3 also proceeds with the formation of conjugated fatty acids followed by hydrogenation, although no conjugated dienes were found. The formation of the novel biohydrogenation intermediates of 18:4n-3 seems to follow an uncommon isomerization pattern with distinct double bond migrations.

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Biohydrogenation of Linolenic Acid to Stearic Acid by the Rumen Microbial Population Yields Multiple Intermediate Conjugated Diene Isomers

Cited by 80 publications

References 23 publications

Selenite and selenate affect the fatty acid profile in in vitro incubated ovine ruminal fluid containing linseed oil

Selenite and selenate affect the fatty acid profile in in vitro incubated ovine ruminal fluid containing linseed oil

Evaluating the effects of six essential oils on fermentation and biohydrogenation in in vitro rumen batch cultures

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

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