Abstract
Conventional beliefs surrounding the linolenic acid (LNA; cis-9 cis-12 cis-15 C18:3) biohydrogenation (BH) pathway propose that it converts to stearic acid (SA) without the formation of conjugated linoleic acid (CLA) as intermediate isomers. However, an advanced study (Lee and Jenkins, 2011) verified that LNA BH yields multiple CLAs. This study utilized the stable isotope tracer to investigate the BH intermediates of 13C-LNA with different pH conditions (5.5 and 6.5). The 13C enrichment was calculated as a 13C/12C ratio of labeled minus unlabeled. After 24 h, eight CLA isomers were significantly enriched on both pH treatment, this result verifies that these CLAs originated from 13C-LNA BH which supports the results of Lee and Jenkins (2011). The enrichment of cis-cis double bond CLAs (cis-9 cis-11 and cis-10 cis-12 CLA) were significantly higher at low pH conditions. Furthermore, the concentration of cis-10 cis-12 CLA at low pH was four times higher than at high pH conditions after a 3 h incubation. These differences support the LNA BH pathways partial switch under different pH conditions, with a strong influence on the cis-cis CLA at low pH. Several mono-, di-, and tri-enoic fatty acid isomers were enriched during 24 h of incubation, but the enrichment was decreased or restricted at low pH treatment. Based on these results, it is proposed that low pH conditions may cause a changed or limited capacity of the isomerization and reduction steps in BH.
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- Invited review: Research on ruminal biohydrogenation—Achievements, gaps in knowledge, and future approaches from the perspective of dairy science
P.G. Toral, G. Hervás, P. Frutos
Journal of Dairy Science.2024; 107(12): 10115. CrossRef - Selenate and selenite affect ruminal metabolism of C18 unsaturated fatty acids and fatty acid composition of lamb tissues
Małgorzata Białek, Marian Czauderna, Wiesław Przybylski, Danuta Jaworska
Livestock Science.2020; 241: 104249. CrossRef - Effects of Supplementation of Rumen Protected Fats on Rumen Ecology and Digestibility of Nutrients in Sheep
Atique A. Behan, Teck Chwen Loh, Sharida Fakurazi, Ubedullah Kaka, Asmatullah Kaka, Anjas Asmara Samsudin
Animals.2019; 9(7): 400. CrossRef - In vitro biohydrogenation of 13C-labeled α-linolenic acid in response to ruminal alterations associated with diet-induced milk fat depression in ewes
P.G. Toral, G. Hervás, P. Frutos
Journal of Dairy Science.2019; 102(2): 1213. CrossRef - Accumulation of conjugated linoleic acid in Lactobacillus plantarum WU-P19 is enhanced by induction with linoleic acid and chitosan treatment
Wilawan Palachum, Wanna Choorit, Yusuf Chisti
Annals of Microbiology.2018; 68(10): 611. CrossRef - The In vitro Effects of Nano-encapsulated Conjugated Linoleic Acid on Stability of Conjugated Linoleic Acid and Fermentation Profiles in the Rumen
Wan Heo, Eun Tae Kim, Sung Do Cho, Jun Ho Kim, Seong Min Kwon, Ha Yeon Jeong, Kwang Seok Ki, Ho Baek Yoon, Young Dae Ahn, Sung Sill Lee, Young Jun Kim
Asian-Australasian Journal of Animal Sciences.2016; 29(3): 365. CrossRef - Sources and Bioactive Properties of Conjugated Dietary Fatty Acids
Alan A. Hennessy, Paul R. Ross, Gerald F. Fitzgerald, Catherine Stanton
Lipids.2016; 51(4): 377. CrossRef - Influence of Carotino oil on in vitro rumen fermentation, metabolism and apparent biohydrogenation of fatty acids
Kazeem Dauda Adeyemi, Mahdi Ebrahimi, Anjas Asmara Samsudin, Abd Razak Alimon, Roselina Karim, Saiful Anuar Karsani, Awis Qurni Sazili
Animal Science Journal.2015; 86(3): 270. CrossRef - Seleno‐methionine decreases biohydrogenation of C18 unsaturated fatty acids in ovine ruminal fluid incubated in vitro with α‐linolenic acid
Marian Czauderna, Agnieszka J. Rozbicka‐Wieczorek, Edyta Więsyk, Katarzyna A. Krajewska‐Bienias
European Journal of Lipid Science and Technology.2015; 117(6): 820. CrossRef