Natalia V. Zhukova

Fatty acid composition of 15 species of marine microalgae

Abstract The fatty acid composition of 15 marine microalgal species, belonging to the Chlorophyceae, Prasinophyceae, Bacillariophyceae, Prymnesiophyceae, Dinophyceae, Eustigmatophyceae, Crytophyceae, Rhodophyceae, and cultured under comparable conditions has been studied. It is shown that each class of microalgae is characterized by a specific fatty acid profile. It is proposed that uncommon acids, some typical acids and the ratio of acids are useful chemotaxonomic markers. The reliable markers of Bacillariophyceae were a preference of 16:1(n-7) over 16:0, high levels of 14:0, 20:5(n-3), C 16 polyunsaturated fatty acids with double bonds at (n-4) and (n-1), and insignificant amounts of C 18 acids and 22:6(n-3). The fatty acid profiles of the different microalgae were compared with previously published data.

The pathway of the biosynthesis of non-methylene-interrupted dienoic fatty acids in molluscs

Abstract 1. 1. The metabolic fate of 1-14C-acetate administered to the marine bivalve mollusc Mytilus edulis was investigated. 2. 2. The active incorporation of the label in 20:2 non-methylene-interrupted dienoic (NMID) fatty acids was found. 3. 3. Acetate incorporation patterns and specific radioactivity of mussel acids suggest that 22:2Δ7,13 and 22:2/gD7,15 arose by C2 elongation of 20:2Δ5,11 and 20:2Δ5,13 respectively. 4. 4. The proposed pathway of NMID fatty acid biosynthesis in molluscs is discussed.

Evaluation of Phospholipid and Fatty Acid Compositions as Chemotaxonomic Markers of Alteromonas-Like Proteobacteria

The cellular phospholipids (PLs) and fatty acids (FAs) were investigated in type and environmental strains of Pseudoalteromonas, Alteromonas macleodii, A. infernus, and in three type strains of Marinomonas, M. communis, M. vaga, M. mediterranea. A total of 40 strains (19 strains in this study and 21 reported in previous papers), including Idiomarina abyssalis, I. zobellii, and Glaciecola punicea, G. pallidula, aerobic Alteromonas-like proteobacteria showed genus-characteristic patterns of phospholipids and fatty acids useful for genera discrimination. The PL patterns of surface cultures of alteromonads, pseudoalteromonads, and marinomonads consisted almost entirely of phosphatidyl ethanolamine and phosphatidyl glycerol presented in different proportions. Neither diphosphatidyl glycerol nor glycophospholipids were found in bacteria studied. In addition, the minor amount of a glycolipid was found in all strains studied. Bacteria of the genera Marinomonas, Idiomarina, and Glaciecola were clearly distinguished by presence of one of the major FAs: 18:1 (n-7), i15:0, and 16:1 (n-7), respectively. The amounts of these FAs reached up to 40–60% of total FAs. Members of Alteromonas and Pseudoalteromonas were characterized by different ratio of the following major FAs:16:1(n-7), 16:0, 17:1 (n-8), and 18:1 (n-7).

Two species of culturable bacteria associated with degradation of brown algae Fucus Evanescens

The heterotrophic microbial enrichment community established during degradation of brown algae Fucus evanescens was characterized. A two-species bacterial community of marine culturable gamma-proteobacteria consisted of Pseudoalteromonas and Halomonas. The first member of the community, Pseudoalteromonas sp., was highly metabolically active, had bacteriolytic and hemolytic activities, produced proteinases (gelatinase and caseinase), lipases, DNases, and fucoidanhydrolases, laminaranases, alginases, pustulanases, beta-glucosidases, beta-galactosidases, beta-N-acetylglucosaminidases, and beta-xylosidases. The second member of the community, Halomonas marina, produced only caseinase and DNase, and it did not hydrolyze algal polysaccharides. Both members of the studied bacterial community utilized a range of easily assimilable monosaccharides and other low molecular weight organic substances. The results provide an evidence of the complex metabolic interrelations between two members of this culturable community. One of them Pseudoalteromonas sp., most likely plays the major role in the initial stages of algal degradation; the other one, H. marina, resistant to the bacteriolytic activity of the former, is able to utilize the products of degradation of polysaccharides.

Composition of fatty acids in plasma and erythrocytes and eicosanoids level in patients with metabolic syndrome

BackgroundDisturbances of the fatty acids composition in plasma and red blood cells and eicosanoid synthesis play an important role in the metabolic syndrome (MS) formation.MethodsThe observation group included 61 people with metabolic syndrome (30 patients with MS and normal levels of insulin, 31 people with MS and insulin resistance - IR). The parameters of carbohydrate and lipid metabolism in blood serum were examined. The composition of nonesterified fatty acids (NEFA), fatty acid (FA) of red blood cells lipids was analyzed by gas-liquid chromatography. Eicosanoids level in MS patients blood serum was studied by enzyme immunoassay.ResultsIn MS patients in the absence of glucose-insulin homeostasis disturbances and in patients with IR the accumulation of polyunsaturated fatty acids (18:2 n6, 18:3 n3, 22:4 n6) and lower pool of saturated FA (12:0, 14:0, 16: 0, 17:0) in plasma were discovered. A deficit of polyunsaturated FA (18:3 n3, 20:4 n6) with a predominance of on-saturated FA (14:0, 18:0) in erythrocyte membranes was revealed. In MS patients regardless of the carbohydrate metabolism status high levels of leukotriene B4 and 6-keto-prostaglandin-F1α in serum were found. The development of IR in MS patients leads to increased synthesis of thromboxane A2.ConclusionThe results revealed a disturbance in nonesterified fatty acids of plasma lipids and red blood cells, eicosanoid synthesis in MS patients. The breach of the plasma and cell membranes fatty acids compositions, synthesis of vasoactive and proinflammatory eicosanoids is an important pathogenetic part of the MS development.

Fatty acid variations in symbiotic dinoflagellates from Okinawan corals

The fatty acid composition of polar lipids and triacylglycerols was determined in different morphophysiological types of symbiotic dinoflagellates (SD) isolated from the hydrocoral Millepora intricata and the scleractinian corals Pocillopora damicornis, Seriatopora caliendrum, Seriatopora hystrix and Stylophora pistillata from a fringing reef of Sesoko Island, Okinawa, Japan. The distribution of the fatty acids among the morphophysiologically distinct types of SD reported in these corals makes it possible to readily distinguish one type of SD from the other. Moreover, differences were found both in polar lipids and triacylglycerols. The polar lipids of SD from M. intricata showed a very distinctive fatty acid profile. A combination of large proportions of 18:4 (n-3), 18:5 (n-3), 22:5 (n-6), and 22:6 (n-3) and negligible amounts of 20:4 (n-6), and 20:5 (n-3) in SD from M. intricata was particularly noteworthy. The fatty acid profiles of SD from P. damicornis and SD isolated from S. caliendrum and S. hystrix differed in the proportion of 18:4 (n-3) and 22:6 (n-3). It is suggested that fatty acids might provide useful information on possible taxonomic differences among symbiotic dinoflagellates. It is assumed that biochemical differences can reflect the genetic diversity of the morphophysiological types of SD associated with several species of hermatypic corals from this region.

DIET-INDUCED CHANGES IN LIPID AND FATTY ACID COMPOSITION OF ARTEMIA SALINA

The influence of diet on lipid and fatty acid composition of the brine shrimp Artemia salina nauplii was investigated. Various diets with different lipid composition and fatty acid profiles were fed to nauplii for 2 weeks. The lipid composition of microalgal diets, Isochrysis galbana, Phaeodactylum tricornutum and Nannochloropsis oculata and bakers yeast was analyzed. Newly hatched nauplii were examined before the feeding experiment. It was shown that Artemia was able to incorporate and selectively concentrate some dietary lipids. Depot lipids were more sensitive to changes in the dietary lipid composition than the main structural lipids, polar lipids and sterols. Variations in the content of the lipid classes correlated with stage of development of the animal. The fatty acid composition of the animal varied with that of diet. The concentrations of saturated fatty acids were apparently supported in the nauplii by biosynthesis de novo. The acid 16:1(n-7) originated from the food. The concentration range of n-6 polyunsaturated fatty acids (PUFAs) remained constant through the accumulation from the diet. The proportion of n-3 PUFAs varied with their level in the diet. The dynamics of alteration of 20:5(n-3) content in Artemia fed on Isochrysis, which is poor in this acid, suggested a limited capacity for elongation and desaturation of 18:3(n-3) to 20:5(n-3). None of the diets provided dietary input of 22:6(n-3)

Lipid Classes and Fatty Acid Composition of the Tropical Nudibranch Mollusks Chromodoris sp. and Phyllidia coelestis

Two nudibranch mollusks, Chromodoris sp. and Phyllidia coelestis, collected from tropical waters of the Northwestern Pacific, were analyzed for lipids. The aim of this study was to fill the gap in knowledge of lipid biochemistry of mollusks. Phospholipids (PL) were the dominating lipid class followed by sterols (13%). Neutral lipids were not detected in Chromodoris sp. By contrast, P. coelestis contained TAG, diacylglyceryl ether, long chain alcohol and esters of sterols. Among PL, PC was predominant (about 50%); PE, PS and CAEP were almost in equal proportions. Sixty five FA were identified as methyl esters and N-acyl pyrrolidides by GC–MS. The sea slugs exhibited a wide diversity of FA. The common marine n-3 PUFA, 20:5n-6 and 22:6n-3, constituted 0.6–1.3% of the total FA, whereas n-6 PUFA, 22:4n-6, 20:4n-6, and 18:2n-6, were the main (25%). Among monounsaturated FA, 7-21:1 was the main (up to 6.2%). The non-methylene-interrupted (NMI) FA were found (9.4 and 12.4%), including the known 5,11–20:2, 5,13–20:2, 7,13–22:2, 7,15–22:2 and a novel isomer 7,13–21:2 (up to 3.9%). The pathway of its biosynthesis was suggested. A series of very long chain FA (VLC FA), with the main 5,9–25:2 and 5,9–26:2, were identified. High level of VLC FA (8.7 and 11.7%) in sea slugs is apparently the result of predation on sponges. Another unique feature concerned a high abundance of various odd and branched FA (16.7 and 34%), which could have originated from the dietary origin or symbiotic bacteria. This is the first report on lipid and FA composition of nudibranchs.

Winogradskyella echinorum sp. nov., a marine bacterium of the family Flavobacteriaceae isolated from the sea urchin Strongylocentrotus intermedius

The taxonomic position of a novel marine, yellow-pigmented bacterium, designated strain KMM 6211(T), was examined by using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain KMM 6211(T) is a member of the family Flavobacteriaceae, phylum Bacteroidetes. The closest relative of strain KMM 6211(T) was Winogradskyella eximia KMM 3944(T), the sequence similarity being 97.1 %. The DNA G+C content of KMM 6211(T) was 33.6 mol%. The strain was motile by gliding and grew with 1-6 % NaCl and at 4-37 degrees C. Aesculin, casein and gelatin were hydrolysed, but agar, starch, DNA and chitin were not degraded. On the basis of phylogenetic data and phenotypic differences between the isolate and recognized Winogradskyella species, strain KMM 6211(T) represents a novel species of the genus Winogradskyella, for which the name Winogradskyella echinorum sp. nov. is proposed. The type strain is KMM 6211(T) (=KCTC 22026(T)=LMG 24757(T)).

Characterization of Aeromonas and Vibrio species isolated from a drinking water reservoir

E.P. IVANOVA, N.V. ZHUKOVA, N.M. GORSHKOVA AND E.L. CHAIKINA. 2001.