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Fatty Acids in Natural Ecosystems and Human Nutrition

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A special issue of Biomolecules (ISSN 2218-273X). This special issue belongs to the section "Natural and Bio-inspired Molecules".

Deadline for manuscript submissions: closed (31 January 2020) | Viewed by 52282

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Special Issue Editor

Prof. Dr. Michail I. Gladyshev

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Guest Editor

1. Institute of Biophysics, Krasnoyarsk Scientific Center, Siberian Branch, Russian Academy of Sciences, 660036 Krasnoyarsk, Russia
2. Institute of Biophysics SB RAS, Siberian Federal University, 660041 Krasnoyarsk, Russia
Interests: limnology; aquatic ecologyhy; hydrobiology; fatty acids
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Special Issue Information

Dear Colleagues,

In the last few decades, fatty acids (FAs), including polyunsaturated acids of omega-3 family (PUFA), appeared to be the focus of attention for biochemists, physiologists, and ecologists. On the one hand, fatty acids, especially long-chain PUFA, are of great physiological importance for animals, including humans, as (i) biochemical precursors of signaling molecules (oxylipins), (ii) structural components of cell membranes of neural tissues, and (iii) ‘‘pacemakers’’ for the metabolism of animal cells (i.e., activators of membrane-bound enzymes). For humans, the consumption of PUFAs, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), is recommended by the World Health Organization in order to prevent cardiovascular diseases and neural disorders. On the other hand, FAs are used as the most reliable biomarkers for tracing fluxes of matter and energy in trophic webs of natural ecosystems, and thereby for evaluating their structure and functions. Among natural ecosystems, water bodies were found to play a peculiar role concerning long-chain PUFAs. Indeed, vascular plants—the main primary producers in terrestrial ecosystems—do not synthesize EPA and DHA. In contrast, some taxa of microalgae produce substantial amounts of EPA and DHA. Once synthesized by microalgae, PUFAs are transferred through trophic webs to organisms of higher trophic levels—invertebrates and fish. Thus, aquatic ecosystems are the main source of physiologically important EPA and DHA for many animals, including some omnivorous terrestrial animals and humans. The ability of aquatic ecosystems to produce long-chain PUFAs, including those for human nutrition, at present, is threatened by many anthropogenic factors, such as pollution, eutrophication climate change, and biological invasions. Thus, the evaluation of fatty acids in natural ecosystems are of considerable importance for pure and applied sciences.

Prof. Michail I. Gladyshev
Guest Editor

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Keywords

omega-3 fatty acids
eicosapentaenoic acid
docosahexaenoic acid
biomarker fatty acids
food webs
trophic transfer

Published Papers (13 papers)

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Research

Jump to: Review

20 pages, 4659 KiB

Open AccessArticle

Variation in ω-3 and ω-6 Polyunsaturated Fatty Acids Produced by Different Phytoplankton Taxa at Early and Late Growth Phase

by Sami Taipale, Elina Peltomaa and Pauliina Salmi

Biomolecules 2020, 10(4), 559; https://doi.org/10.3390/biom10040559 - 06 Apr 2020

Cited by 20 | Viewed by 3338

Abstract

Phytoplankton synthesizes essential ω-3 and ω-6 polyunsaturated fatty acids (PUFA) for consumers in the aquatic food webs. Only certain phytoplankton taxa can synthesize eicosapentaenoic (EPA; 20:5ω3) and docosahexaenoic acid (DHA; 22:6ω3), whereas all phytoplankton taxa can synthesize shorter-chain ω-3 and ω-6 PUFA. Here, we experimentally studied how the proportion, concentration (per DW and cell-specific), and production (µg FA L⁻¹ day⁻¹) of ω-3 and ω-6 PUFA varied among six different phytoplankton main groups (16 freshwater strains) and between exponential and stationary growth phase. EPA and DHA concentrations, as dry weight, were similar among cryptophytes and diatoms. However, Cryptomonas erosa had two–27 times higher EPA and DHA content per cell than the other tested cryptophytes, diatoms, or golden algae. The growth was fastest with diatoms, green algae, and cyanobacteria, resulting in high production of medium chain ω-3 and ω-6 PUFA. Even though the dinoflagellate Peridinium cinctum grew slowly, the content of EPA and DHA per cell was high, resulting in a three- and 40-times higher production rate of EPA and DHA than in cryptophytes or diatoms. However, the production of EPA and DHA was 40 and three times higher in cryptophytes and diatoms than in golden algae (chrysophytes and synyrophytes), respectively. Our results show that phytoplankton taxon explains 56–84% and growth phase explains ~1% of variation in the cell-specific concentration and production of ω-3 and ω-6 PUFA, supporting understanding that certain phytoplankton taxa play major roles in the synthesis of essential fatty acids. Based on the average proportion of PUFA of dry weight during growth, we extrapolated the seasonal availability of PUFA during phytoplankton succession in a clear water lake. This extrapolation demonstrated notable seasonal and interannual variation, the availability of EPA and DHA being prominent in early and late summer, when dinoflagellates or diatoms increased. Full article

(This article belongs to the Special Issue Fatty Acids in Natural Ecosystems and Human Nutrition)

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18 pages, 1189 KiB

Open AccessArticle

Comparison of Fatty Acid Contents in Major Lipid Classes of Seven Salmonid Species from Siberian Arctic Lakes

by Nadezhda N. Sushchik, Olesia N. Makhutova, Anastasia E. Rudchenko, Larisa A. Glushchenko, Svetlana P. Shulepina, Anzhelika A. Kolmakova and Michail I. Gladyshev

Biomolecules 2020, 10(3), 419; https://doi.org/10.3390/biom10030419 - 08 Mar 2020

Cited by 15 | Viewed by 2682

Abstract

Long-chain omega-3 polyunsaturated fatty acids (LC-PUFA) essential for human nutrition are mostly obtained from wild-caught fish. To sustain the LC-PUFA supply from natural populations, one needs to know how environmental and intrinsic factors affect fish fatty acid (FA) profiles and contents. We studied seven Salmoniformes species from two arctic lakes. We aimed to estimate differences in the FA composition of total lipids and two major lipid classes, polar lipids (PL) and triacylglycerols (TAG), among the species and to evaluate LC-PUFA contents corresponding to PL and TAG in muscles. Fatty acid profiles of PL and TAG in all species were characterized by the prevalence of omega-3 LC-PUFA and C16-C18 monoenoic FA, respectively. Fish with similar feeding spectra were identified similarly in multivariate analyses of total lipids, TAG and PL, due to differences in levels of mostly the same FA. Thus, the suitability of both TAG and total lipids for the identification of the feeding spectra of fish was confirmed. All species had similar content of LC-PUFA esterified as PL, 1.9–3.5 mg g⁻¹, while the content of the TAG form strongly varied, from 0.9 to 9.8 mg g⁻¹. The LC-PUFA-rich fish species accumulated these valuable compounds predominately in the TAG form. Full article

(This article belongs to the Special Issue Fatty Acids in Natural Ecosystems and Human Nutrition)

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24 pages, 5617 KiB

Open AccessArticle

Tiny but Fatty: Lipids and Fatty Acids in the Daubed Shanny (Leptoclinus maculatus), a Small Fish in Svalbard Waters

by Svetlana A. Murzina, Svetlana N. Pekkoeva, Ekaterina A. Kondakova, Zinaida A. Nefedova, Kseniia A. Filippova, Nina N. Nemova, Alexei M. Orlov, Jorgen Berge and Stig Falk-Petersen

Biomolecules 2020, 10(3), 368; https://doi.org/10.3390/biom10030368 - 28 Feb 2020

Cited by 22 | Viewed by 3858

Abstract

The seasonal dynamic of lipids and their fatty acid constituents in the lipid sac and muscles of pelagic postlarval Leptoclinus maculatus, an ecologically important fish species in the Arctic food nets, in Kongsfjord, Svalbard waters was studied. The determination of the qualitative and quantitative content of the total lipids (TLs), total phospholipids (PLs), triacylglycerols (TAGs), cholesterol (Chol), cholesterol esters (Chol esters) and wax esters was analyzed by TLC, the phosphatidylserine (PS), phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylcholine (PC), lysophosphatidylcholine (LPC) and sphingomyelin (SM) were determined by HPLC, and fatty acids of total lipids using GC. The lipid sac is a system of cavities filled with lipids, and it is not directly connected to organs of the digestive system. The wall’s inner layer is a multinuclear symplast that has a trophic function. The results provide additional knowledge on the role of lipids in the biochemical and physiological adaptation of fish to specific environments and clarify the relationship between fatty acids and the food specialization of postlarvae. Analysis of the fatty acid (FA) profile of TLs in the muscles and lipid sac of daubed shanny pelagic postlarvae showed it to be tissue- and organ-specific, and tightly associated with seasonal variations of environmental factors (temperature conditions and trophic resources). Full article

(This article belongs to the Special Issue Fatty Acids in Natural Ecosystems and Human Nutrition)

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15 pages, 836 KiB

Open AccessArticle

Fatty Acid Content and Composition of the Yakutian Horses and Their Main Food Source: Living in Extreme Winter Conditions

by Klim A. Petrov, Lyubov V. Dudareva, Vasiliy V. Nokhsorov, Kirill N. Stoyanov and Olesia N. Makhutova

Biomolecules 2020, 10(2), 315; https://doi.org/10.3390/biom10020315 - 17 Feb 2020

Cited by 9 | Viewed by 3596

Abstract

For the first time, seasonal changes in the content of total lipids (TLs) and phospholipids (PLs) were studied in fodder plants growing in Central Yakutia—a perennial cereal, smooth brome (Bromopsis inermis L.), and an annual cereal, common oat (Avena sativa L.). Both species have concentrated TLs and PLs in autumn under cold hardening. In addition, a significant increase in the content of fatty acids (FAs) of B. inermis was observed during the autumn decrease in temperature. The Yakutian horses, which fed on cereals enriched with nutrients preserved by natural cold (green cryo-fodder), accumulated significant amounts of 18:2n-6 and 18:3n-3, the total content of which in cereals was 75% of the total FA content. We found differences in the distribution of these two FAs in different tissues of the horses. Thus, liver was rich in 18:2n-6, while muscle and adipose tissues accumulated mainly 18:3n-3. Such a distribution may indicate different roles of these FAs in the metabolism of the horses. According to FA content, meat of the Yakutian horses is a valuable dietary product. Full article

(This article belongs to the Special Issue Fatty Acids in Natural Ecosystems and Human Nutrition)

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19 pages, 2205 KiB

Open AccessArticle

Preliminary Estimations of Insect Mediated Transfers of Mercury and Physiologically Important Fatty Acids from Water to Land

by Sydney Moyo

Biomolecules 2020, 10(1), 129; https://doi.org/10.3390/biom10010129 - 13 Jan 2020

Cited by 9 | Viewed by 2678

Abstract

Aquatic insects provide an energy subsidy to riparian food webs. However, most empirical studies have considered the role of subsidies only in terms of magnitude (using biomass measurements) and quality (using physiologically important fatty acids), negating an aspect of subsidies that may affect their impact on recipient food webs: the potential of insects to transport contaminants (e.g., mercury) to terrestrial ecosystems. To this end, I used empirical data to estimate the magnitude of nutrients (using physiologically important fatty acids as a proxy) and contaminants (total mercury (Hg) and methylmercury (MeHg)) exported by insects from rivers and lacustrine systems in each continent. The results reveal that North American rivers may export more physiologically important fatty acids per unit area (93.0 ± 32.6 Kg Km⁻² year⁻¹) than other continents. Owing to the amount of variation in Hg and MeHg, there were no significant differences in MeHg and Hg among continents in lakes (Hg: 1.5 × 10⁻⁴ to 1.0 × 10⁻³ Kg Km⁻² year⁻¹; MeHg: 7.7 × 10⁻⁵ to 1.0 × 10⁻⁴ Kg Km⁻² year⁻¹) and rivers (Hg: 3.2 × 10⁻⁴ to 1.1 × 10⁻³ Kg Km⁻² year⁻¹; MeHg: 3.3 × 10⁻⁴ to 8.9 × 10⁻⁴ Kg Km⁻² year⁻¹), with rivers exporting significantly larger quantities of mercury across all continents than lakes. Globally, insect export of physiologically important fatty acids by insect was estimated to be ~43.9 × 10⁶ Kg year⁻¹ while MeHg was ~649.6 Kg year⁻¹. The calculated estimates add to the growing body of literature, which suggests that emerging aquatic insects are important in supplying essential nutrients to terrestrial consumers; however, with the increase of pollutants in freshwater systems, emergent aquatic insect may also be sentinels of organic contaminants to terrestrial consumers. Full article

(This article belongs to the Special Issue Fatty Acids in Natural Ecosystems and Human Nutrition)

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13 pages, 480 KiB

Open AccessArticle

Natural CLA-Enriched Lamb Meat Fat Modifies Tissue Fatty Acid Profile and Increases n-3 HUFA Score in Obese Zucker Rats

by Gianfranca Carta, Elisabetta Murru, Claudia Manca, Andrea Serra, Marcello Mele and Sebastiano Banni

Biomolecules 2019, 9(11), 751; https://doi.org/10.3390/biom9110751 - 19 Nov 2019

Cited by 3 | Viewed by 3372

Abstract

Ruminant fats are characterized by different levels of conjugated linoleic acid (CLA) and α-linolenic acid (18:3n-3, ALA), according to animal diet. Tissue fatty acids and their N-acylethanolamides were analyzed in male obese Zucker rats fed diets containing lamb meat fat with different fatty acid profiles: (A) enriched in CLA; (B) enriched in ALA and low in CLA; (C) low in ALA and CLA; and one containing a mixture of olive and corn oils: (D) high in linoleic acid (18:2n-6, LA) and ALA, in order to evaluate early lipid metabolism markers. No changes in body and liver weights were observed. CLA and ALA were incorporated into most tissues, mirroring the dietary content; eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) increased according to dietary ALA, which was strongly influenced by CLA. The n-3 highly-unsaturated fatty acid (HUFA) score, biomarker of the n-3/n-6 fatty acid ratio, was increased in tissues of rats fed animal fats high in CLA and/or ALA compared to those fed vegetable fat. DHA and CLA were associated with a significant increase in oleoylethanolamide and decrease in anandamide in subcutaneous fat. The results showed that meat fat nutritional values are strongly influenced by their CLA and ALA contents, modulating the tissue n-3 HUFA score. Full article

(This article belongs to the Special Issue Fatty Acids in Natural Ecosystems and Human Nutrition)

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14 pages, 2407 KiB

Open AccessArticle

Fish Oil, but Not Olive Oil, Ameliorates Depressive-Like Behavior and Gut Microbiota Dysbiosis in Rats under Chronic Mild Stress

by Te-Hsuan Tung, Yu-Tang Tung, I-Hsuan Lin, Chun-Kuang Shih, Ngan Thi Kim Nguyen, Amalina Shabrina and Shih-Yi Huang

Biomolecules 2019, 9(10), 516; https://doi.org/10.3390/biom9100516 - 21 Sep 2019

Cited by 20 | Viewed by 5563

Abstract

Background: This study investigated the effects of fish oil and olive oil in improving dysbiosis and depressive-like symptoms. Methods and results: Male rats were fed normal, fish oil-rich or olive oil-rich diets for 14 weeks. Chronic mild stress (CMS) was administered from week 2. The sucrose preference test (SPT) and forced swimming test (FST) were used to determine depressive-like behavior. The SPT results revealed that the CMS, CMS with imipramine (CMS+P) treatment, and CMS with olive oil diet (CMS+O) groups exhibited significantly reduced sucrose intake from week 8, whereas the fish oil diet (CMS+F) group exhibited significantly reduced sucrose intake from week 10. The FST results showed that the immobile time of the CMS+F group was significantly less than that of the CMS-only group. Next generation sequencing (NGS) results showed CMS significantly reduced the abundance of Lactobacillus and increased that of Marvinbryantia and Ruminiclostridium_6. However, the CMS+F group showed an increase in the abundance of Eisenbergiella, Ruminococcaceae_UCG_009, and Holdemania, whereas the CMS+O group showed an increase in the abundance of Akkermansia. Conclusions: CMS stimuli altered the gut microbiome in depressed rats. Fish oil and olive oil exerted part of a prebiotic-like effect to ameliorate dysbiosis induced by CMS. However, only fish oil ameliorated depressive-like symptoms. Full article

(This article belongs to the Special Issue Fatty Acids in Natural Ecosystems and Human Nutrition)

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13 pages, 1765 KiB

Open AccessArticle

Origin of Carbon and Essential Fatty Acids in Higher Trophic Level Fish in Headwater Stream Food Webs

by Megumu Fujibayashi, Yoshie Miura, Reina Suganuma, Shinji Takahashi, Takashi Sakamaki, Naoyuki Miyata and So Kazama

Biomolecules 2019, 9(9), 487; https://doi.org/10.3390/biom9090487 - 13 Sep 2019

Cited by 9 | Viewed by 2848

Abstract

Dietary carbon sources in headwater stream food webs are divided into allochthonous and autochthonous organic matters. We hypothesized that: 1) the dietary allochthonous contribution for fish in headwater stream food webs positively relate with canopy cover; and 2) essential fatty acids originate from autochthonous organic matter regardless of canopy covers, because essential fatty acids, such as 20:5ω3 and 22:6ω3, are normally absent in allochthonous organic matters. We investigated predatory fish Salvelinus leucomaenis stomach contents in four headwater stream systems, which are located in subarctic region in northern Japan. In addition, stable carbon and nitrogen isotope ratios, fatty acid profile, and stable carbon isotope ratios of essential fatty acids were analyzed. Bulk stable carbon analysis showed the major contribution of autochthonous sources to assimilated carbon in S. leucomaenis. Surface baits in the stomach had intermediate stable carbon isotope ratios between autochthonous and allochthonous organic matter, indicating aquatic carbon was partly assimilated by surface baits. Stable carbon isotope ratios of essential fatty acids showed a positive relationship between autochthonous sources and S. leucomaenis across four study sites. This study demonstrated that the main supplier of dietary carbon and essential fatty acids was autochthonous organic matter even in headwater stream ecosystems under high canopy cover. Full article

(This article belongs to the Special Issue Fatty Acids in Natural Ecosystems and Human Nutrition)

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10 pages, 1201 KiB

Open AccessCommunication

Limited Antioxidant Effect of Rosemary in Lipid Oxidation of Pan-Fried Salmon

by Kin Sum Leung, Ho Hang Leung, Ching Yu Wu, Jean-Marie Galano, Thierry Durand and Jetty Chung-Yung Lee

Biomolecules 2019, 9(8), 313; https://doi.org/10.3390/biom9080313 - 28 Jul 2019

Cited by 14 | Viewed by 3892

Abstract

Consumption of omega-3 polyunsaturated fatty acids (n-3 PUFAs) rich fatty fish is known to provide an array of health benefits. However, high temperature in food preparation, such as pan-frying, potentially degrades eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) of the n-3 PUFAs by heat oxidation. The addition of antioxidant condiments, and herbs in particular, may retard PUFA peroxidation and preserve EPA and DHA during pan-frying. In this study, different types of antioxidant condiments (sage, rosemary, black peppercorn, thyme, basil, and garlic) were tested for antioxidant capacity, and the condiment with the highest capacity was selected for its effect on lipid oxidation of salmon. The changes in fatty acids and lipid peroxidation of salmon, during pan-frying with the selected condiment (olive oil infused with rosemary, RO_(infused)), were compared with salmon prepared in extra virgin olive oil, olive oil, or without oil. The total saturated fatty acid was found to be less in pan fried salmon with RO_(infused). None of the oil type conserved EPA- and DHA-content in salmon. However, RO_(infused) lowered lipid peroxidation by lessening hydroperoxide and 4-HNE formation, but not the other related products (HDHA, HETE, isoprostanes). Our observation indicates that the antioxidant capacity of RO_(infused), when it is incorporated with food, becomes limited. Full article

(This article belongs to the Special Issue Fatty Acids in Natural Ecosystems and Human Nutrition)

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17 pages, 435 KiB

Open AccessArticle

Impact of Water Pollution on Trophic Transfer of Fatty Acids in Fish, Microalgae, and Zoobenthos in the Food Web of a Freshwater Ecosystem

by Shahid Mahboob, Khalid Abdullah Al-Ghanim, Fahad Al-Misned, Tehniat Shahid, Salma Sultana, Tayyaba Sultan, Bilal Hussain and Zubair Ahmed

Biomolecules 2019, 9(6), 231; https://doi.org/10.3390/biom9060231 - 14 Jun 2019

Cited by 14 | Viewed by 4337

Abstract

This research work was carried out to determine the effects of water contamination on the fatty acid (FA) profile of periphyton, zoobenthos, two Chinese carps and a common carp (Hypophthalmichthys molitrix, Ctenopharygodon idella and Cyprinus carpio), captured from highly polluted (HP), less polluted (LP), and non-polluted (NP) sites of the Indus river. We found that the concentration of heavy metals in the river water from the polluted locations exceeded the permissible limits suggested by the World Health Organization (WHO) and the US Environmental Protection Agency (EPA). Fatty acid profiles in periphyton, zoobenthos, H. molitrix, C. idella, and C. carpio in the food web of river ecosystems with different pollution levels were assessed. Lauric acid and arachidic acids were not detected in the biomass of periphyton and zoobenthos from HP and LP sites compared to NP sites. Alpha-linolenic acid (ALA), eicosadienoic acid and docosapentaenoic acid were not recorded in the biomass samples of periphyton and zoobenthos in both HP and LP sites. Caprylic acid, lauric acid, and arachidic acid were not found in H. molitrix, C. idella, and C. carpio captured from HP. In this study, 6 and 9 omega series FAs were identified in the muscle samples of H. molitrix, C. idella and C. carpio captured from HP and LP sites compared to NP sites, respectively. Less polyunsaturated fatty acids were observed in the muscle samples of H. molitrix, C. idella, and C. carpio collected from HP than from LP. The heavy metals showed significant negative correlations with the total FAs in periphyton, zoobenthos, and fish samples. Full article

(This article belongs to the Special Issue Fatty Acids in Natural Ecosystems and Human Nutrition)

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Review

Jump to: Research

13 pages, 1298 KiB

Open AccessReview

Assessment of Fatty Acid Desaturase (Fads2) Structure-Function Properties in Fish in the Context of Environmental Adaptations and as a Target for Genetic Engineering

by Zuzana Bláhová, Thomas Nelson Harvey, Martin Pšenička and Jan Mráz

Biomolecules 2020, 10(2), 206; https://doi.org/10.3390/biom10020206 - 31 Jan 2020

Cited by 17 | Viewed by 4459

Abstract

Fatty acid desaturase 2 (Fads2) is the key enzyme of long-chain polyunsaturated fatty acid (LC-PUFA) biosynthesis. Endogenous production of these biomolecules in vertebrates, if present, is insufficient to meet demand. Hence, LC-PUFA are considered as conditionally essential. At present, however, LC-PUFA are globally limited nutrients due to anthropogenic factors. Research attention has therefore been paid to finding ways to maximize endogenous LC-PUFA production, especially in production species, whereby deeper knowledge on molecular mechanisms of enzymatic steps involved is being generated. This review first briefly informs about the milestones in the history of LC-PUFA essentiality exploration before it focuses on the main aim—to highlight the fascinating Fads2 potential to play roles fundamental to adaptation to novel environmental conditions. Investigations are summarized to elucidate on the evolutionary history of fish Fads2, providing an explanation for the remarkable plasticity of this enzyme in fish. Furthermore, structural implications of Fads2 substrate specificity are discussed and some relevant studies performed on organisms other than fish are mentioned in cases when such studies have to date not been conducted on fish models. The importance of Fads2 in the context of growing aquaculture demand and dwindling LC-PUFA supply is depicted and a few remedies in the form of genetic engineering to improve endogenous production of these biomolecules are outlined. Full article

(This article belongs to the Special Issue Fatty Acids in Natural Ecosystems and Human Nutrition)

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25 pages, 2417 KiB

Open AccessEditor’s ChoiceReview

Fatty Acids of Marine Mollusks: Impact of Diet, Bacterial Symbiosis and Biosynthetic Potential

by Natalia V. Zhukova

Biomolecules 2019, 9(12), 857; https://doi.org/10.3390/biom9120857 - 11 Dec 2019

Cited by 43 | Viewed by 5258

Abstract

The n-3 and n-6 polyunsaturated fatty acid (PUFA) families are essential for important physiological processes. Their major source are marine ecosystems. The fatty acids (FAs) from phytoplankton, which are the primary producer of organic matter and PUFAs, are transferred into consumers via food webs. Mollusk FAs have attracted the attention of researchers that has been driven by their critical roles in aquatic ecology and their importance as sources of essential PUFAs. The main objective of this review is to focus on the most important factors and causes determining the biodiversity of the mollusk FAs, with an emphasis on the key relationship of these FAs with the food spectrum and trophic preference. The marker FAs of trophic sources are also of particular interest. The discovery of new symbioses involving invertebrates and bacteria, which are responsible for nutrition of the host, deserves special attention. The present paper also highlights recent research into the molecular and biochemical mechanisms of PUFA biosynthesis in marine mollusks. The biosynthetic capacities of marine mollusks require a well-grounded evaluation. Full article

(This article belongs to the Special Issue Fatty Acids in Natural Ecosystems and Human Nutrition)

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17 pages, 832 KiB

Open AccessReview

Long-chain Omega-3 Polyunsaturated Fatty Acids in Natural Ecosystems and the Human Diet: Assumptions and Challenges

by Michail I. Gladyshev and Nadezhda N. Sushchik

Biomolecules 2019, 9(9), 485; https://doi.org/10.3390/biom9090485 - 12 Sep 2019

Cited by 40 | Viewed by 5257

Abstract

Over the past three decades, studies of essential biomolecules, long-chain polyunsaturated fatty acids of the omega-3 family (LC-PUFAs), namely eicosapentaenoic acid (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA), have made considerable progress, resulting in several important assumptions. However, new data, which continue to appear, challenge these assumptions. Based on the current literature, an attempt is made to reconsider the following assumptions: 1. There are algal classes of high and low nutritive quality. 2. EPA and DHA decrease with increasing eutrophication in aquatic ecosystems. 3. Animals need EPA and DHA. 4. Fish are the main food source of EPA and DHA for humans. 5. Culinary treatment decreases EPA and DHA in products. As demonstrated, some of the above assumptions need to be substantially specified and changed. Full article

(This article belongs to the Special Issue Fatty Acids in Natural Ecosystems and Human Nutrition)

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