scholarly journals Metabolism of conjugated linoleic acids and 18 : 1 fatty acids by ruminal bacteria: products and mechanisms

Microbiology ◽  
2010 ◽  
Vol 156 (2) ◽  
pp. 579-588 ◽  
Author(s):  
Nest McKain ◽  
Kevin J. Shingfield ◽  
R. John Wallace
Keyword(s):  
Fatty Acids ◽  
Linoleic Acid ◽  
Unsaturated Fatty Acids ◽  
Deuterium Oxide ◽  
Geometric Isomers ◽  
Conjugated Linoleic Acids ◽  
Ruminal Bacteria ◽  
Butyrivibrio Fibrisolvens ◽  
Cla Isomers ◽  
Deuterium Enrichment

Cultures of ruminal bacteria known to metabolize unsaturated fatty acids were grown in medium containing 50 μg ml−1 of geometric and positional isomers of conjugated linoleic acid (CLA) or 18 : 1 fatty acids and 37.4 % deuterium oxide to investigate the mechanisms responsible for fatty acid metabolism. Butyrivibrio fibrisolvens JW11 converted cis-9,trans-11-18 : 2 and trans-9,trans-11-18 : 2 to trans-11-18 : 1 as the main product, labelled at C-9, and metabolized trans-10,cis-12-18 : 2 to trans-10-18 : 1, labelled at C-13, and smaller amounts of trans-12-18 : 1 and cis-12-18 : 1. Butyrivibrio proteoclasticus P-18 did not grow in the presence of cis-9,trans-11-18 : 2 or trans-10,cis-12-18 : 2, but grew in medium containing trans-9,trans-11-18 : 2, forming 18 : 0. Propionibacterium acnes, a ruminal species that isomerizes linoleic acid to trans-10,cis-12-18 : 2, did not metabolize CLA isomers further. B. fibrisolvens metabolized small amounts of trans-10-18 : 1, trans-11-18 : 1 and cis-9-18 : 1, but the products formed were not detected. B. proteoclasticus, on the other hand, carried out substantial conversion of 18 : 1 substrates to 18 : 0. P. acnes hydrated cis-9-18 : 1 and trans-11-18 : 1 to 10-OH-18 : 0, which was further oxidized to yield 10-O-18 : 0. The deuterium enrichment in the intermediates formed during incubations with 9,11 geometric isomers of CLA was about half that of the products from trans-10,cis-12 CLA and 18 : 1 isomers, suggesting that the reduction of 9,11 geometric isomers CLA by ruminal bacteria occurs via different mechanisms compared with the metabolism of other unsaturated fatty acids.

scholarly journals CONJUGATED LINOLEIC ACID AND CANCER IN HUMANS-IS THERE A ROLE OR NOT? A REVIEW OF THE SCIENTIFIC EVIDENCE

10.37512/300 ◽  
2019 ◽  
Keyword(s):  
Fatty Acids ◽  
Linoleic Acid ◽  
Clinical Studies ◽  
Unsaturated Fatty Acids ◽  
Scientific Evidence ◽  
Epidemiological Studies ◽  
Ruminal Bacteria ◽  
Butyrivibrio Fibrisolvens ◽  
Gender Diverse ◽  
And Gender

Conjugated linoleic acids are naturally occurring fatty acids that are found predominantly in ruminant meat, milk and dairy products. They are composed mainly of two isomers: cis-9, trans-11 and trans-10, cis-12 fatty acid. Their synthesis occurs mainly by the action of ruminal bacteria, Butyrivibrio Fibrisolvens, and a host of lactic acid bacteria, which isomerize linoleic acid to CLA or by synthesis via α9-desaturase of 11-trans octadecanoic acid, and, through desaturation of free linoleic acid or other unsaturated fatty acids. Although cis-9, trans-11 and trans-9, trans-11 CLA isomers have consistently shown anti-carcinogenicity on animal models and on cancerous human cells, results from clinical trials are inconclusive and conflicting. Despite most of the data on humans being mainly from epidemiological studies, a few clinical studies with breast and colorectal cancer sufferers have shown some promise. Controlled, long-term, racial and gender diverse, geographically spread clinical studies are required to understand the link between CLA intake and incidence of human cancers.

scholarly journals Influence of fish oil on ruminal biohydrogenation of C18 unsaturated fatty acids

2006 ◽  
Vol 95 (6) ◽  
pp. 1199-1211 ◽  
Author(s):  
I. Wąsowska ◽  
M. R. G. Maia ◽  
K. M. Niedźwiedzka ◽  
M. Czauderna ◽  
J. M. C. Ramalho Ribeiro ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Linoleic Acid ◽  
Fish Oil ◽  
Unsaturated Fatty Acids ◽  
Butyrivibrio Fibrisolvens ◽  
Isomerase Activity ◽  
Epa And Dha ◽  
Pure Cultures ◽  
Ruminal Biohydrogenation

Dietarycis-9,trans-11-conjugated linoleic acid (CLA) is generally thought to be beneficial for human health. Fish oil added to ruminant diets increases the CLA concentration of milk and meat, an increase thought to arise from alterations in ruminal biohydrogenation of unsaturated fatty acids. To investigate the mechanism for this effect,in vitroincubations were carried out with ruminal digesta and the main biohydrogenating ruminal bacterium,Butyrivibrio fibrisolvens. Linoleic acid (LA) or α-linolenic acid (LNA) was incubated (1·67g/l) with strained ruminal digesta from sheep receiving a 50:50 grass hay–concentrate ration. Adding fish oil (up to 4·17g/l) tended to decrease the initial rate of LA (P=0·025) and LNA (P=0·137) disappearance, decreased (P<0·05) the transient accumulation of conjugated isomers of both fatty acids, and increased (P<0·05) the accumulation oftrans-11-18:1. Concentrations of EPA (20:5n-3) or DHA (22:6n-3), the major fatty acids in fish oil, were low (100mg/l or less) after incubation of fish oil with ruminal digesta. Addition of EPA or DHA (50mg/l) to pure cultures inhibited the growth and isomerase activity ofB. fibrisolvens, while fish oil had no effect. In contrast, similar concentrations of EPA and DHA had no effect on biohydrogenation of LA by mixed digesta, while the addition of LA prevented metabolism of EPA and DHA. Neither EPA nor DHA was metabolised byB. fibrisolvensin pure culture. Thus, fish oil inhibits ruminal biohydrogenation by a mechanism which can be interpreted partly, but not entirely, in terms of its effects onB. fibrisolvens.

scholarly journals Conjugated Linoleic Acid Production by Bifidobacteria: Screening, Kinetic, and Composition

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Stefano Raimondi ◽  
Alberto Amaretti ◽  
Alan Leonardi ◽  
Andrea Quartieri ◽  
Caterina Gozzoli ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Linoleic Acid ◽  
Spectrophotometric Assay ◽  
Geometric Isomers ◽  
Conjugated Linoleic Acids ◽  
Esterified Fatty Acids ◽  
Plasmatic Membrane ◽  
Hydratase Activity ◽  
First Time ◽  
Producer Strains

Conjugated linoleic acids (CLA) are positional and geometric isomers of linoleic acid involved in a number of health aspects. In humans, CLA production is performed by gut microbiota, including some species of potential probiotic bifidobacteria. 128 strains of 31Bifidobacteriumspecies were screened with a spectrophotometric assay to identify novel CLA producers. Most species were nonproducers, while producers belonged toB. breveandB. pseudocatenulatum. GC-MS revealed that CLA producer strains yielded 9cis,11trans-CLA and 9trans,11trans-CLA, without any production of other isomers. Hydroxylated forms of LA were absent in producer strains, suggesting that the myosin-cross-reactive antigen (MCRA) protein that exerts hydratase activity is not involved in LA isomerization. Moreover, both CLA producer and nonproducer species bear a MCRA homologue. The strainB. breveWC 0421 was the best CLA producer, converting LA into 68.8% 9cis,11trans-CLA and 25.1% 9trans,11trans-CLA. Production occurred mostly during the lag and the exponential phase. For the first time, production and incorporation of CLA in biomass were assessed.B. breveWC 0421 stored CLA in the form of free fatty acids, without changing the composition of the esterified fatty acids, which mainly occurred in the plasmatic membrane.

Conjugated linoleic acid and trans C18:1 in muscle and adipose tissue of lambs fed supplements containing n-3 polyunsaturated fatty acids

2002 ◽  
Vol 2002 ◽  
pp. 182-182
Author(s):  
M. Enser ◽  
A.M. Wachira ◽  
L.A. Sinclair ◽  
R.G Wilkinson ◽  
K.G. Hallett ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Linoleic Acid ◽  
Polyunsaturated Fatty Acids ◽  
Fish Oil ◽  
Unsaturated Fatty Acids ◽  
Vaccenic Acid ◽  
Conjugated Linoleic Acids ◽  
Relationship Of ◽  
The Relationship

Conjugated linoleic acids (CLA) occur in the milk and tissues of ruminants. Although cis-9, trans-11 CLA is an intermediate in the biohydrogenation of linoleic acid in the rumen, duodenal flows of CLA are very low (Scollan et al, 2001) and most CLA appears to be synthesised in tissues from trans-11 C18:1 (vaccenic acid) (Griinari et al, 2000). Trans C18:1 isomers are also produced in the rumen and their amounts are increased when the levels of dietary unsaturated fatty acids are raised. We have investigated the relationship of tissue levels of CLA and trans C18:1 in three breeds of lambs fed supplements of linseed or fish oil to increase trans C18:1.

scholarly journals Explore the gene network regulating the composition of fatty acids in cottonseed

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lihong Ma ◽  
Xinqi Cheng ◽  
Chuan Wang ◽  
Xinyu Zhang ◽  
Fei Xue ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Linolenic Acid ◽  
Gene Network ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Accumulation Pattern ◽  
Time Points ◽  
Expression Characteristics

Abstract Background Cottonseed is one of the major sources of vegetable oil. Analysis of the dynamic changes of fatty acid components and the genes regulating the composition of fatty acids of cottonseed oil is of great significance for understanding the biological processes underlying biosynthesis of fatty acids and for genetic improving the oil nutritional qualities. Results In this study, we investigated the dynamic relationship of 13 fatty acid components at 12 developmental time points of cottonseed (Gossypium hirsutum L.) and generated cottonseed transcriptome of the 12 time points. At 5–15 day post anthesis (DPA), the contents of polyunsaturated linolenic acid (C18:3n-3) and saturated stearic acid (C18:0) were higher, while linoleic acid (C18:2n-6) was mainly synthesized after 15 DPA. Using 5 DPA as a reference, 15,647 non-redundant differentially expressed genes were identified in 10–60 DPA cottonseed. Co-expression gene network analysis identified six modules containing 3275 genes significantly associated with middle-late seed developmental stages and enriched with genes related to the linoleic acid metabolic pathway and α-linolenic acid metabolism. Genes (Gh_D03G0588 and Gh_A02G1788) encoding stearoyl-ACP desaturase were identified as hub genes and significantly up-regulated at 25 DPA. They seemed to play a decisive role in determining the ratio of saturated fatty acids to unsaturated fatty acids. FAD2 genes (Gh_A13G1850 and Gh_D13G2238) were highly expressed at 25–50 DPA, eventually leading to the high content of C18:2n-6 in cottonseed. The content of C18:3n-3 was significantly decreased from 5 DPA (7.44%) to 25 DPA (0.11%) and correlated with the expression characteristics of Gh_A09G0848 and Gh_D09G0870. Conclusions These results contribute to our understanding on the relationship between the accumulation pattern of fatty acid components and the expression characteristics of key genes involved in fatty acid biosynthesis during the entire period of cottonseed development.

scholarly journals Fatty acid positional distribution (sn-2 fatty acids) and phospholipid composition in Chinese breast milk from colostrum to mature stage

2018 ◽  
Vol 121 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Ke Wu ◽  
Runying Gao ◽  
Fang Tian ◽  
Yingyi Mao ◽  
Bei Wang ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Fatty Acid Profile ◽  
Unsaturated Fatty Acids ◽  
Fatty Acid Content ◽  
Positional Distribution ◽  
Phospholipid Composition ◽  
Mature Stage ◽  
Feeding Time

AbstractThis study quantified the fatty acid profile with emphasis on the stereo-specifically numbered (sn) 2 positional distribution in TAG and the composition of main phospholipids at different lactation stages. Colostrum milk (n 70), transitional milk (n 96) and mature milk (n 82) were obtained longitudinally from healthy lactating women in Shanghai. During lactation, total fatty acid content increased, with SFA dominating in fatty acid profile. A high ratio of n-6:n-3 PUFA was observed as 11:1 over lactation due to the abundance of linoleic acid in Chinese human milk. As the main SFA, palmitic acid showed absolute sn-2 selectivity, while oleic acid, linoleic acid and α-linolenic acid, the main unsaturated fatty acids, were primarily esterified at the sn-1 and sn-3 positions. Nervonic acid and C22 PUFA including DHA were more enriched in colostrum with an sn-2 positional preference. A total of three dominant phospholipids (phosphatidylethanolamine (PE), phosphatidylcholine (PC) and sphingomyelin (SM)) were analysed in the collected samples, and each showed a decline in amount over lactation. PC was the dominant compound followed by SM and PE. With prolonged breast-feeding time, percentage of PE in total phospholipids remained constant, but PC decreased, and SM increased. Results from this study indicated a lipid profile different from Western reports and may aid the development of future infant formula more suitable for Chinese babies.

scholarly journals Inhibition of steroid 5α-reductase by specific aliphatic unsaturated fatty acids

1992 ◽  
Vol 285 (2) ◽  
pp. 557-562 ◽  
Author(s):  
T Liang ◽  
S Liao
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Linoleic Acid ◽  
Linolenic Acid ◽  
Unsaturated Fatty Acids ◽  
Binding Assay ◽  
Reductase Activity ◽  
Undecylenic Acid ◽  
Gamma Linolenic Acid ◽  
Enzymic Assay

Human or rat microsomal 5 alpha-reductase activity, as measured by enzymic conversion of testosterone into 5 alpha-dihydrotestosterone or by binding of a competitive inhibitor, [3H]17 beta-NN-diethulcarbamoyl-4-methyl-4-aza-5 alpha-androstan-3-one ([3H]4-MA) to the reductase, is inhibited by low concentrations (less than 10 microM) of certain polyunsaturated fatty acids. The relative inhibitory potencies of unsaturated fatty acids are, in decreasing order: gamma-linolenic acid greater than cis-4,7,10,13,16,19-docosahexaenoic acid = cis-6,9,12,15-octatetraenoic acid = arachidonic acid = alpha-linolenic acid greater than linoleic acid greater than palmitoleic acid greater than oleic acid greater than myristoleic acid. Other unsaturated fatty acids such as undecylenic acid, erucic acid and nervonic acid, are inactive. The methyl esters and alcohol analogues of these compounds, glycerols, phospholipids, saturated fatty acids, retinoids and carotenes were inactive even at 0.2 mM. The results of the binding assay and the enzymic assay correlated well except for elaidic acid and linolelaidic acid, the trans isomers of oleic acid and linoleic acid respectively, which were much less active than their cis isomers in the binding assay but were as potent in the enzymic assay. gamma-Linolenic acid had no effect on the activities of two other rat liver microsomal enzymes: NADH:menadione reductase and glucuronosyl transferase. gamma-Linolenic acid, the most potent inhibitor tested, decreased the Vmax. and increased Km values of substrates, NADPH and testosterone, and promoted dissociation of [3H]4-MA from the microsomal reductase. gamma-Linolenic acid, but not the corresponding saturated fatty acid (stearic acid), inhibited the 5 alpha-reductase activity, but not the 17 beta-dehydrogenase activity, of human prostate cancer cells in culture. These results suggest that unsaturated fatty acids may play an important role in regulating androgen action in target cells.

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