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

колективна монографія

Кримінальний процесуальний кодекс 2012 року: ідеологія та практика правозастосування: колективна монографія / за заг. ред. Ю. П. Аленіна ; відпов. за вип. І. В. Гловюк. - Одеса : Видавничий дім «Гельветика», 2018. - 1148 с

Accumulation and distribution of

Accumulation of transuranic element 241Am by photoassimilating organs and its distribution in fractions of the biomass of aquatic plant Elodea canadensis have been investigated in laboratory batch experiments. Americium was taken up by apical shoots of Elodea from water. Of the activity accumulated by the shoots, up to 80% of 241Am was detected in the leaves and 20% in the stems. Americium concentration in apical leaves was several times higher than in distal leaves. Of the 241Am activity concentrated in the shoots, 95% was bound to cell walls, membranes and organelles and 5% of the radionuclide was dissolved in cytoplasm. Less than 1% of americium accumulated in the biomass was found in the lipid extract; up to 10% of americium was bound to proteins and carbohydrates; the major part of the radionuclide (about 90%) was registered in the cell wall fraction that mainly contained cellulose-like polysaccharides. Biomass treatment with hydrochloric acid resulted in desorption of about 70% of americium, mostly from the polysaccharides

Waterbugs (Heteroptera: Nepomorpha and Gerromorpha) as sources of essential n-3 polyunsaturated fatty acids in Central Siberian ecoregions

1. Aquatic systems are considered to be a main source of essential long-chain n-3 polyunsaturated fatty acids (PUFA), which are preferentially synthesized by microalgae and transferred along food chains to terrestrial consumers. Emerging aquatic insects comprise a significant part of this transfer of the essential PUFA from water to land. Quantitative data on PUFA content and composition are available mainly for rheophilic insects while taxa that are characteristic of wetlands and stagnant water bodies, such as aquatic Heteroptera, remain relatively unstudied. 2. We investigated the role of various waterbug taxa (Heteroptera: Nepomorpha and Gerromorpha) inhabiting different ecoregions in temperate Central Siberia (Russia) as potential sources of PUFA. The ecoregions were steppe, forest-steppe, hemiboreal forest and montane coniferous forest. Although these waterbugs insects are aquatic in both larval and adult stages, they can disperse through the landscape and transfer essential PUFAs from water to land so making them potentially available to terrestrial consumers. 3. Species of Naucoridae, Notonectidae and Corixidae were generally dominant in all ecoregions, attaining maximum biomass in the steppe. We showed that habitat or ecoregion played a major role in the variability of fatty acid composition of Notonectidae and Gerridae but not Corixidae. In contrast, the biochemical composition of the only naucoridae, Ilyocoris cimicoides, was largely affected by life stage. 4. Both the dominant families and species within them differed with respect to their mass-specific contents of essential long-chain PUFA of the n-3 family, namely eicosapentaenoic and docosahexaenoic acids. Corixid species had the highest content of these two essential PUFAs among the waterbug studies, and relative to literature reports for other aquatic insects. Corixids thus appear to be a potentially important vector for transfer of the essential biochemical compounds from water to land, especially in steppe ecoregions with numerous ephemeral water bodies

Secondary production of highly unsaturated fatty acids by zoobenthos across rivers contrasting in temperature

Highly unsaturated fatty acids (HUFA), namely eicosapentaenoic acid (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA), which are essential for many animals, including humans, are mainly produced in aquatic trophic webs. In fast-flowing rivers, macrozoobenthos is the main source of HUFA for fish and may be particularly vulnerable to thermal alterations associated with climate change. We studied benthic communities in a unique natural ecosystem: the Yenisei River downstream of the dam of Krasnoyarsk Hydroelectric Power Station with very low temperature in summer because of discharge of cold water from deep in the reservoir and its tributaries with high summer temperature. This ‘natural experiment’ allowed to get rid of confounding factors, such as differences in light, seasonality, geology (biogeochemistry) and biogeography (regional species pools). As found, in spite of an increase of biodiversity and rates of daily production in warm rivers compared with cold sites, DHA and partly EPA production of zoobenthos decreased with the increase of temperature because of changes in species composition. Thus, in a climate warming context, we can predict a decrease of production of these HUFA by river zoobenthos and thereby a diminishing of their supply for fish and next to humans

Characteristics of Fatty Acid Composition of Gammarus lacustris Inhabiting Lakes with and without Fish

Текст статьи не публикуется в открытом доступе в соответствии с политикой журнала.—The effect of a biotic factor—the presence of predatory fish in water—on the composition and content of fatty acids in crustaceans was studied in the populations of the lake amphipod Gammarus lacustris from two lakes with fish and three lakes without fish. It was found that, at an overall increase in the quantity and quality of food resources (namely, increase in the content of eicosapentaenoic acid and docosahexaenoic acid (DHA) in the biomass), the relative rate of DHA accumulation in gammarids in the lakes without fish is higher than in the lake with fish

Biological aspects of the associations of biting midges (Diptera: Ceratopogonidae) in two saline rivers of the Elton Lake Basin, Russia.

We studied species composition, density, biomass and production of larvae of the family Ceratopogonidae in two saline rivers (Volgograd region, Russia). Ceratopoponids make up an important part of macroinvertebrate community in these rivers. Average monthly production (dry weight) of ceratopogonid larvae in the rivers was 3.5–4.8 gm-2 month-1 in May and, ̴ 0.9 gm-2 month-1 in August. For the first time, feeding spectra of ceratopogonid larvae, Palpomyia schmidti Goetghebuer, 1934, was studied using fatty acid analyses. The larvae of P. schmidti appeared to selectively consume diatoms and other algae and to avoid bacteria and decomposed dead organic matter (detritus) of low nutritive quality

Characteristics of Fatty Acid Composition of Gammarus lacustris Inhabiting Lakes with and without Fish

Текст статьи не публикуется в открытом доступе в соответствии с политикой журнала.—The effect of a biotic factor—the presence of predatory fish in water—on the composition and content of fatty acids in crustaceans was studied in the populations of the lake amphipod Gammarus lacustris from two lakes with fish and three lakes without fish. It was found that, at an overall increase in the quantity and quality of food resources (namely, increase in the content of eicosapentaenoic acid and docosahexaenoic acid (DHA) in the biomass), the relative rate of DHA accumulation in gammarids in the lakes without fish is higher than in the lake with fish

Influence of Salinity on Growth and Biochemical Composition of Green Alga Botryococcus braunii Kütz IPPAS H-252

Исследовано влияние солености на рост одноклеточной водоросли Botryococcus braunii Kütz IPPAS H-252, содержание общего азота и липидов, а также состав жирных кислот (ЖК), каротиноидов и углеводородов в биомассе. Показано, что присутствие в среде NaCl (0,3 М и 0,7 M) в течение первых трех суток ингибировало рост водоросли, приводило к снижению содержания общего азота и увеличению доли триацилглицеринов. Кроме того, в присутствии NaCl на третьи сутки произошли значительные изменения в составе ЖК водоросли, заключающиеся в снижении содержания полиненасыщенных кислот (ПНЖК) (до 29,4 и 12,8 % от суммы ЖК), увеличении доли олеиновой кислоты (до 20,0 и 21,8 %) и длинноцепочечных насыщенных ЖК (до 5,3 и 14,1 %) при 0,3 и 0,7 M NaCl соответственно. На 7 и 12-е сутки (при 0,3 M NaCl) содержание ПНЖК было таким же, как и в фазе активного роста водоросли. Увеличение доли ПНЖК при 0,7 M NaCl было менее значительным, но так же, как и при 0,3 M NaCl, увеличивались биомасса культуры и концентрация общего азота в клетках, что свидетельствует о возможности адаптации данной водоросли к исследованным концентрациям NaCl.The effect of 0,3 and 0,7 M NaCl on biomass yield, total nitrogen content, intracellular lipid content, hydrocarbons and fatty acid profile of the lipids of the alga Botryococcus braunii Kütz IPPAS H-252 in different phases of the culture cycle was studied. The presence of sodium chloride in the medium inhibited the growth of algal cells for the first three days of the experiment, causing a decrease in total nitrogen, enhanced synthesis of triacylglycerols. In addition, considerable changes in the lipid fatty acid profile were found, i.e. decrease in polyunsaturated fatty acid (PUFA) levels (29,38 % and 12,8 %) and levels of long-chain saturated acids (5,3 % and 14,13 % of the total) at 0,3 M NaCl and 0,7 M NaCl, respectively. In later phases of the culture, at 0,3 M NaCl, the PUFA content increased up to the values characteristic of the active growth phase of the alga. At 0,7 M NaCl, the proportion of PUFA enhanced at less extent, but biomass concentration and total nitrogen increased, similarly to the experiment with 0,3 M NaCl, that may also be indicative of adaptation of the alga to the studied concentrations of NaCl