Fatty Acid Content and Composition of Fly Larvae Lucilia sericata (Family Calliphoridae) Grown on Diets with Different Content of Polyunsaturated Fatty Acids and the Amino Acid Composition of this Species

Аквакультура – быстроразвивающаяся отрасль сельского хозяйства, однако сейчас она столкнулась с недостатком кормов, основу которых составляют уловы дикой рыбы, и, как следствие, повышением их стоимости. Для дальнейшего устойчивого развития аквакультуры необходимо разработать альтернативные корма, производимые не из дикой рыбы. Насекомые рассматриваются как подходящий источник кормового белка для рыб, однако их жирнокислотный (ЖК) состав часто не соответствует требованиям аквакультуры. В рыбьем жире среди ПНЖК доминируют кислоты семейства омега‑3, а в наземных насекомых – семейства омега‑6. Исследование возможности модификации ЖК состава личинок насекомых для увеличения содержания омега‑3 ПНЖК является актуальной задачей. Целью данной работы было изучить состав и содержание жирных кислот в личинках мухи Lucilia sericata, выращенных на стандартном корме и корме с добавлением рыжикового масла, богатом альфа-линоленовой кислотой (АЛК, 18:3n‑3), и проанализировать аминокислотный состав (АК) личинок данного вида мух. ЖК анализ проводили на газовом хроматографе с масс-спектрометрическим детектором. АК анализ выполняли на жидкостном хроматографе. АК состав исследованных личинок мух, как и других насекомых отряда Diptera, был близок к АК составу рыбной муки. Состав и содержание жирных кислот личинок мухи на стандартном корме характеризовались низким соотношением омега‑3 / омега‑6 ПНЖК и доминированием 18:1n‑9 и 18:2n‑6 – жирных кислот, которые суммарно составляли от 40 % до 60 % от суммы ЖК. Добавление рыжикового масла изменило соотношение омега‑3 / омега‑6 ПНЖК с 0,11 до 0,46, главным образом за счёт увеличения содержания АЛК. Таким образом, ЖК состав личинок L. sericata может быть существенно модифицирован пищейAquaculture is a fast-growing branch of agriculture, but it faces fish feed shortages due to a decrease in wild fish catches. As a result, the price of feed increases. For further development it requires alternative feed sources. Insects are considered a suitable protein source for fish, but their fatty acid (FA) composition often does not meet the requirements of aquaculture. In fish oil, PUFAs are dominated by the omega‑3 family, and in terrestrial insects, by the omega‑6 family. A question arises whether insect larvae lipid composition can be modified to increase the content of omega‑3 PUFAs. For this purpose, Lucilia sericata larvae were grown on standard feed and feed with addition of camelina oil rich in alpha-linolenic acid (ALA, 18:3n‑3), and their FA content and composition were compared. To evaluate the quality of these larvae protein, their amino acid (AA) composition was determined. The FA analysis was performed on a gas chromatograph equipped with a mass-spectrometer detector. The AA analysis was performed on a liquid chromatograph. The AA composition of the examined fly larvae, similarly to other insects (Diptera), was close to the AA composition of fish meal. Fatty acid composition and content of fly larvae grown on standard food was characterized by a low ratio of omega‑3/omega‑6 PUFAs and by the dominance of 18:1n‑9 and 18:2n‑6 fatty acids, which together comprised 40–60 % of the total of FAs. The addition of camelina oil changed the ratio of omega‑3/ omega‑6 PUFAs from 0.11 to 0.46, mainly due to the increase in ALA content. Thus, FA content and composition of L. sericata larvae can be significantly modified by a die

Stable Isotope Composition of Fatty Acids in Organisms of Different Trophic Levels in the Yenisei River

We studied four-link food chain, periphytic microalgae and water moss (producers), trichopteran larvae (consumers I), gammarids (omnivorous – consumers II) and Siberian grayling (consumers III) at a littoral site of the Yenisei River on the basis of three years monthly sampling. Analysis of bulk carbon stable isotopes and compound specific isotope analysis of fatty acids (FA) were done. As found, there was a gradual depletion in 13C contents of fatty acids, including essential FA upward the food chain. In all the trophic levels a parabolic dependence of δ13C values of fatty acids on their degree of unsaturation/chain length occurred, with 18:2n-6 and 18:3n-3 in its lowest point. The pattern in the δ13C differences between individual fatty acids was quite similar to that reported in literature for marine pelagic food webs. Hypotheses on isotope fractionation were suggested to explain the findings

Fatty Acid Content and Composition of Freshwater Planaria Dendrocoelopsis sp. (Planariidae, Turbellaria, Platyhelminthes) from the Yenisei River

For the first time the fatty acid content and composition of freshwater planarian Dendrocoelopsis sp. has been studied in a station of the large Siberian River, the Yenisei. The dominant fatty acids were palmitic, oleic, eicosapentaenoic and docosapentaenoic acids. The characteristic feature of planarian fatty acid composition was that ω3 docosapentaenoic acid was 2-10 times higher than docosahexaenoic acid. The average content of ω3 PUFA in the planarian was significantly higher than that of ω6 PUFA, 7.20±1.21 and 1.22±0.22 mg/g of wet weight, respectively. The content of sum ω3 PUFAs which are essential for the nutrition of aquatic organisms of the higher trophic levels in the studied planarian was comparatively high

Fatty Acid Content and Composition of Freshwater Planaria Dendrocoelopsis sp. (Planariidae, Turbellaria, Platyhelminthes) from the Yenisei River

For the first time the fatty acid content and composition of freshwater planarian Dendrocoelopsis sp. has been studied in a station of the large Siberian River, the Yenisei. The dominant fatty acids were palmitic, oleic, eicosapentaenoic and docosapentaenoic acids. The characteristic feature of planarian fatty acid composition was that ω3 docosapentaenoic acid was 2-10 times higher than docosahexaenoic acid. The average content of ω3 PUFA in the planarian was significantly higher than that of ω6 PUFA, 7.20±1.21 and 1.22±0.22 mg/g of wet weight, respectively. The content of sum ω3 PUFAs which are essential for the nutrition of aquatic organisms of the higher trophic levels in the studied planarian was comparatively high

The benefit-risk analysis of omega-3 polyunsaturated fatty acids and heavy metals in seven smoked fish species from Siberia

In cold-smoked species of genus Coregonus, identified by molecular genetic analysis, contents of fatty acids and heavy metals and arsenic were measured. The highest content of sum of long-chain polyunsaturated fatty acids of omega-3 family (LC-PUFA), namely eicosapentaenoic (EPA) and docosahexaenoic (DHA) fatty acids, 6.53 ± 0.78 mg g−1 wet weight, was characteristic of tugun Coregonus tugun. This is the first quantitative estimation (mg LC-PUFA per g of product) of the nutritive value of smoked fish. Thus, to obtain a daily personal doze of EPA+DHA of 1 g, recommended for prevention of cardiovascular diseases, one needs to consume 153 g of the smoked tugun. Metals' contents did not exceed standards for fish meat except Pb in least cisco Coregonus sardinella. Accordingly, values of hazard quotients, which estimate benefit-risk ratio of fish intake, indicate that most of the smoked fish species are safe product for human nutrition, except least cisco regarding Pb content

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

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

Average isotope composition of fatty acids in water moss <i>Fontinalis antipyretica</i> from the littoral of the Yenisei River.

<p>Bars represent standard errors.</p

Average (± standard error) δ¹³C values (‰) of fatty acids (FA) of total lipids and triacylglycerols of <i>Eulimnogammarus lacustris</i> from littoral sites of the Yenisei River and significance of their differences according to Student's <i>t</i>-test for dependent pairs and Wilcoxon matched pairs T-test for number of pairs n = 9.

<p>Average (± standard error) δ¹³C values (‰) of fatty acids (FA) of total lipids and triacylglycerols of <i>Eulimnogammarus lacustris</i> from littoral sites of the Yenisei River and significance of their differences according to Student's <i>t</i>-test for dependent pairs and Wilcoxon matched pairs T-test for number of pairs n = 9.</p

Average values of the isotope ratios (‰) in phytoperiphyton (prpht), <i>Apatania crymophila</i> (trchpt), <i>Eulimnogammarus viridis</i> (gammar), Siberian grayling <i>Thymallus arcticus</i> and water moss <i>Fontinalis antipyretica</i> from the littoral of the Yenisei River near Krasnoyarsk, 2008–2011.

<p>Average values of the isotope ratios (‰) in phytoperiphyton (prpht), <i>Apatania crymophila</i> (trchpt), <i>Eulimnogammarus viridis</i> (gammar), Siberian grayling <i>Thymallus arcticus</i> and water moss <i>Fontinalis antipyretica</i> from the littoral of the Yenisei River near Krasnoyarsk, 2008–2011.</p

Schematic of synthesis of fatty acids from pool of acetate with relative isotope composition values of the pool and the acids, arranged along δ¹³C axe. Transferases/desaturases provide the kinetic isotope effect, resulting in the isotope depletion in the synthesized fatty acid, 18:3n-3, while elognase adds carbon atom from the acetate pool and thereby provides the isotope enrichment in the synthesized fatty acid, 20:5n-3.

<p>A number of intermediate fatty acids are substituted by “…”.</p