Lipid Composition, Cytotoxic and Acetylcholinesterase Inhibition Effects of Two Brown Algae Species Lobophora tsengii and Lobophora australis

In this paper, the lipid classes, compositions of the neutral lipids, phospholipids and fatty acids, acetylcholinesterase inhibition and cytotoxic activity of two brown algae Lobophora tsengii D. Tien & Z. Sun and Lobophora australis Z. Sun, F. C. Gurgel & H. Kawai have been investigated. The polar lipid class had the highest content in total lipid (TL) (43.47% in L. tsengii and 48.95% in L. australis). Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were the main components in the phospholipids of two studied brown algae with contents varied from 32.27% to 52.33%. Total lipids were rich in PUFA (42.54% of total fatty acids for L. australis and 32.98% for L. tsengii), with EPA (11.46%, 14.30%) and AA (8.0%, 11.96%). L. tsengii methanol extract inhibited acetylcholinesterase (AChE) in in vitro assay with an IC50 value of 25.45 µg/mL. Both Lobophora methanol extracts display cytotoxic effects against four human cancer cell lines (KB, MCF7, HepG2 and A549) with IC50 in the range of 21.11-83.61 µg/mL. Especially, L. australis extract showed a strong cytotoxicity against KB cell lines with IC50 value of 21.11±0.39 µg/mL.

N-Stearoylethanolamine Exerts Cardioprotective Effects in Old Rats

BACKGROUND

Aging is associated with the slowing down of metabolic processes, diminished physiological processes, changes in hormonal activity and increasing exposure to oxidative stress factors and chronic inflammation. The endocannabinoid system (ECS) is a major signaling network that plays a pro-homeostatic role in the central and peripheral organs of the human body. A class of minor lipids, N-acylethanolamines (NAEs), which do not activate cannabinoid receptors, except for anandamide, but can potentiate the action of endocannabinoids and have a wide spectrum of biological activity and significant adaptogenic potential, belongs to ECS. The results of different studies over the past decades have established the protective effect of NAE on many pathological conditions.

OBJECTIVE

This study aimed to investigate the cardioprotective effects of C18:0 NAE- N-stearoylethanolamine (NSE) in aged rats. In this study, we focused on investigating the effects of C18:0 NAE- N-stearoylethanolamine (NSE) on the intensity of oxidative/ nitrosative stress, antioxidant potential, lipoprotein profile and inflammation markers of blood plasma, phospholipid composition and age-related morphological changes of old rat heart tissues.

METHODS

The study was conducted on Sprague Dawley male laboratory rats. The three groups of rats were involved in the study design. The first group consisted of young rats aged 4 months (n=10). The second (n=10) and third (n=10) groups included old rats aged of 18 months. Rats from the third group were administered a per os aqueous suspension of NSE at a dose of 50 mg/kg of body weight daily for 10 days. All groups of rats were kept on a standard vivarium diet. The blood plasma, serum, and heart of rats were used for biochemical and histological analysis.

RESULTS

The cardioprotective effect of N-stearoylethanolamine in old rats was established, which was expressed in the normalization of the antioxidant system condition and the level of proinflammatory cytokines, positive modulation of blood plasma and lipoprotein profile, normalization of heart tissue lipid composition, and significant reduction in age-related myocardium morphological changes.

CONCLUSION

The revealed effects of N-stearoylethanolamine can become the basis for developing a new drug for use in complex therapy to improve the quality of life of older people.

Effects of Trehalose Supplementation on Lipid Composition of Rooster Spermatozoa Membranes in a Freeze/Thaw Protocol

The plasma membrane of spermatozoa plays an important role in the formation and maintenance of many functions of spermatozoa, including during cryopreservation. As a result of chromatographic analysis, the content of lipids and fatty acids in the membranes of spermatozoa of roosters of two breeds was determined under the influence of cryoprotective media containing trehalose LCM-control (0 mM), Treh20 (9.5 mM), and Treh30 (13.4 mM). The use of the cryoprotective diluent Treh20 made it possible to maintain a dynamic balance between the synthesis and degradation of phospholipids and sterols in the plasma membranes of frozen/thawed spermatozoa, close to that of native spermatozoa. This contributed to an increase in the preservation of frozen/thawed spermatozoa membranes from 48.3% to 52.2% in the egg breed and from 30.0% to 35.1% in the meat- and-egg breed. It was also noted that their kinetic apparatus (mobility indicators) remained at the level of 45.6% (egg breed) and 52.4% (meat-and-egg breed). An increase in the concentration of trehalose to 13.4 mM in a cryoprotective diluent for rooster sperm resulted in a decrease in the morphofunctional parameters of frozen/thawed spermatozoa.

The effect of vitamin E on the lipid environment of rat hepatocyte membranes

Tocopherol is one of the known beneficial natural antioxidants ensuring the optimal level of functioning of mammalian organisms. Numerous in vitro and in vivo experiments have shown that the biological role of vitamin E is to prevent the development of pathologies caused by oxidative stress. In particular, the role of enzymatic factors of lipid peroxidation and related inflammation as a result of eicosanoid synthesis was clearly shown. We studied changes in the structural and functional state of hepatocyte membranes in the classical model of E-hypovitaminosis caused by long-term (70 days) insufficient intake of vitamin E in the diet of rats. The test components were determined spectrophotometrically after appropriate chromatographic procedures. The amount of total and individual leukotrienes was determined by ELISA. Prolonged tocopherol deficiency in rats caused a 49.4% decrease in tocopherol, more than 27.0% – in cholesterol. Of the 8 individual phospholipids studied, 6 showed significant changes: a decrease in cardiolipin and phosphatidylserine, and an increase in phosphatidylethanolamine by 3.24 times, an increse in lysophosphatidylcholine by 86.9%, in phospha­tidylcholine by 52.8%, and in sphingomyelin by 30.6%, relative to control. There were changes in the levels of unsaturated fatty acids playing a significant role in the development of functional disorders in cells and affecting the metabolism of ecosanoids derived from arachidonic acid by the 5-lipoxygenase oxidation pathway. Changes in the levels of total and individual cysteinyl leukotrienes in the state of E-hypovitaminosis were revealed. Restoration of vitamin E intake returns most of the studied indicators such as tocopherol, cholesterol, polyunsaturated fatty acids to the control levels and activates the processes of sequential conversion of leukotrienes in the body of rats. The obtained results indicate the potentiating effect of vitamin E on metabolic processes in the body as a whole and in hepatocytes and eicosanoid metabolism. The degree of tocopherol intake allows one to influence the course of inflammatory processes associated with eicosanoids, not only through the impact on precursors, but also on the utilization of metabolites, including leukotrienes.

Pseudomonas xionganensis sp. nov., isolated from Baiyangdian Lake in Xiong'an New Area

An aerobic, Gram-stain-negative, rod-shaped bacterium, designated as strain R-22-3 w-18^T, was isolated from Baiyangdian Lake in Xiong'an New Area, PR China. Growth was observed at 15-37 °C (optimum, 30 °C) and pH 7.0-10.0 (optimum, pH 8.0). 16S rRNA gene sequence analysis placed the strain in a separate branch in the Pseudomonas putida group, with Pseudomonas anguilliseptica DSM12111^T as its closest phylogenetic relative (98.2 %). Whole-genome comparisons, using average nucleotide identity (ANI), average amino acid identity (AAI) and digital DNA-DNA hybridization (dDDH) analyses, confirmed low genome relatedness to the closely related Pseudomonas species [below the recommended thresholds of 95 % (ANI), 95 % (AAI) and 70 % (DDH) for species delineation]. Phenotypic characterization tests could also distinguish this strain from other related species of the genus Pseudomonas. Therefore, based on genetic and phenotypic evidence, it is clear that strain R-22-3 w-18^T represents a novel species of the genus Pseudomonas, for which the name Pseudomonas xionganensis sp. nov. is proposed. The type strain is R-22-3 w-18^T (=CGMCC 1.17250^T=KCTC 72658^T).

Membrane sterols and genes of sterol biosynthesis are involved in the response of Triticum aestivum seedlings to cold stress

Cold stress can significantly alter the composition and functioning of the major membrane lipids in plants. However, the roles of the sterol component of plant membranes in stress tolerance remain unclear. In the work presented here we investigated the role of sterols in the response of wheat to cold stress. Initial experiments demonstrated that the roots and leaves of wheat seedlings are differentially sensitive to low positive temperatures. In the roots, cold stress induced disturbance of membrane integrity and accumulation of ROS followed by the induction of autophagy. The absence of such changes in leaves suggests that in wheat, the roots are more sensitive to cold than the leaves. The roots display a time-dependent parabolic pattern of cold stress response, characterized by raised levels of sterols and markers of oxidative stress during short-term treatment, and a decline of these parameters after prolonged treatment. MβCD-induced sterol depletion aggravated the negative effects of cold on the roots. In the leaves the changes also displayed parabolic patterns, with significant changes occurring in 24-ethyl sterols and major PLs. Constitutively high levels of sterols, glycolipids and PLs, and up-regulation of TaSMTs in the leaves may provide membrane stability and cold tolerance. Taken together, results suggest that sterols play important roles in the response of wheat seedlings to cold stress.

Phosphatidic acids mediate transport of Ca2+ and H+ through plant cell membranes

Phosphatidic acids (PAs) are a key intermediate in phospholipid biosynthesis, and a central element in numerous signalling pathways. Functions of PAs are related to their fundamental role in molecular interactions within cell membranes modifying membrane bending, budding, fission and fusion. Here we tested the hypothesis that PAs are capable of direct transport of ions across bio-membranes. We have demonstrated that PAs added to the maize plasma membrane vesicles induced ionophore-like transmembrane transport of Ca2+, H+ and Mg2+. PA-induced Ca2+ fluxes increased with an increasing PAs acyl chain unsaturation. For all the PAs analysed, the effect on Ca2+ permeability increased with increasing pH (pH 8.0>pH 7.2>pH 6.0). The PA-induced Ca2+, Mg2+ and H+ permeability was also more pronounced in the endomembrane vesicles as compared with the plasma membrane vesicles. Addition of PA to protoplasts from Arabidopsis thaliana (L.) Heynh. roots constitutively expressing aequorin triggered elevation of the cytosolic Ca2+ activity, indicating that the observed PA-dependent Ca2+ transport occurs in intact plants.

Fatty Acid, Lipid Classes and Phospholipid Molecular Species Composition of the Marine Clam Meretrix lyrata (Sowerby 1851) from Cua Lo Beach, Nghe An Province, Vietnam

This study aims to analyze compositions of fatty acids and phospholipid molecular species in the hard clams Meretrix lyrata (Sowerby, 1851) harvested from Cua Lo beach, Nghe An province, Viet Nam. Total lipid of hard clams Meretrix lyrata occupied 1.7 ± 0.2% of wet weight and contained six classes: hydrocarbon and wax (HW), triacylglycerol (TAG), free fatty acids (FFA), sterol (ST), polar lipid (PoL), and monoalkyl diacylglycerol (MADAG). Among the constituents, the proportion of PoL accounted was highest, at 45.7%. In contrast, the figures for MADAG were lowest, at 1.3%. Twenty-six fatty acids were identified with the ratios of USAFA/SAFA was 2. The percentage of n-3 PUFA (ω-3) and n-6 PUFA (ω-6) was high, occupying 38.4% of total FA. Among PUFAs, arachidonic acid (AA, 20:4n-6), eicosapentaenoic acid (EPA, 20:5n-3), docosapentaenoic acid (DPA, 22:5n-3), and docosahexaenoic acid (DHA, 22:6n-3) accounted for 3.8%, 7.8%, 2.2% and 12.0% of total lipid of the clam respectively. Phospholipid molecular species were identified in polar lipids of the clams consisting six types: phosphatidylethalnolamine (PE, with 28 molecular species), phosphatidylcholine (PC, with 26 molecular species), phosphatidylserine (PS, with 18 molecular species), phosphatidylinositol (PI, with 10 molecular species), phosphatidylglycerol (PG, with only one molecular species), and ceramide aminoethylphosphonate (CAEP, with 15 molecular species). This is the first time that the molecular species of sphingophospholipid were determined, in Meretrix lyrata in particular, and for clams in general. Phospholipid formula species of PE and PS were revealed to comprise two kinds: Alkenyl acyl glycerophosphoethanolamine and Alkenyl acyl glycerophosphoserine occupy 80.3% and 81.0% of total PE and PS species, respectively. In contrast, the percentage of diacyl glycero phosphatidylcholine was twice as high as that of PakCho in total PC, at 69.3, in comparison with 30.7%. In addition, phospholipid formula species of PI and PG comprised only diacyl glycoro phospholipids. PE 36:1 (p18:0/18:1), PC 38:6 (16:0/22:6), PS 38:1 (p18:0/20:1), PI 40:5 (20:1/20:4), PG 32:0 (16:0/16:0) and CAEP 34:2 (16:2/d18:0) were the major molecular species.

Phospholipids of New Zealand Edible Brown Algae

Edible brown algae have attracted interest as a source of beneficial allenic carotenoid fucoxanthin, and glyco- and phospholipids enriched in polyunsaturated fatty acids. Unlike green algae, brown algae contain no or little phosphatidylserine, possessing an unusual aminophospholipid, phosphatidyl-O-[N-(2-hydroxyethyl) glycine], PHEG, instead. When our routinely used technique of 31P-NMR analysis of phospholipids was applied to the samples of edible New Zealand brown algae, a number of signals corresponding to unidentified phosphorus-containing compounds were observed in total lipids. NI (negative ion) ESI QToF MS spectra confirmed the presence of more familiar phospholipids, and also suggested the presence of PHEG or its isomers. The structure of PHEG was confirmed by comparison with a synthetic standard. An unusual MS fragmentation pattern that was also observed prompted us to synthesise a number of possible candidates, and was found to follow that of phosphatidylhydroxyethyl methylcarbamate, likely an extraction artefact. An unexpected outcome was the finding of ceramidephosphoinositol that has not been reported previously as occurring in brown algae. An uncommon arsenic-containing phospholipid has also been observed and quantified, and its TLC behaviour studied, along with that of the newly synthesised lipids.

[The effect of N-stearoylethanolamine on liver phospholipid composition of rats with insulin resistance caused by alimentary obesity]

We used alimentary obesity-induced insulin resistance (IR) model in rats to investigate the influence of N-stearoylethanolamine on the content of phospholipids and their fatty acid composition. Our results show that prolonged high-fat diet triggers considerable aberrations in the composition of main phospholipids in the liver and can be one of the causes of IR in rats. In particular, the increase of phosphatidylcholine, phosphatidylethanolamine and significant decrease of other phospholipids: lysophosphatidylcholine, lysophosphatidylethanolamine, sphingomyelin, phosphatidylinositol, phosphatidylserine and diphosphaglicerol were observed. The levels of monounsaturated (erucic, nervonic, oleic) and polyunsaturated (eicosatrienoic, docosatrienoic, arachidonic) fatty acids were increased; meanwhile the content of diunsaturated acids was decreased. The NSE administration (50 mg/kg of body weight) caused restoration of the phospholipids content in the liver of rats with diet-induced IR that highly correlated with the decrease in plasma insulin level and the improvement of insulin sensitivity. Moreover, the effect of NSE was accompanied by the normalization of fatty acids composition of phospholipids that could be related to modulating influence of NSE on the activity of the main fatty acid desaturases. It is known that the imbalance in phospholipid composition of the rat liver causes substantial metabolic alterations that are associated with the development of IR. Accordingly, the compensations of the imbalance by NSE can help to restore insulin sensitivity, inhibit the development of obesity, IR and type 2 diabetes.

Aliidiomarina shirensis sp. nov., a halophilic bacterium isolated from Shira Lake in Khakasia, southern Siberia, and a proposal to transfer Idiomarina maris to the genus Aliidiomarina

Strain AIST, an aerobic halophilic, Gram-reaction-negative, heterotrophic bacterium isolated from the water of Shira Lake in Khakasia, southern Siberia, was characterized using a polyphasic approach. Our analysis of the 16S rRNA gene sequences showed that ‘Aliidiomarina haloalkalitolerans’, ‘Aliidiomarina sanyensis’, Idiomarina maris and AIST formed a distinct lineage. The sequence similarities between AIST and the type strains of species of the genera Idiomarina and Aliidiomarina were 91.6–95.1 % and 94.0–96.9 %, respectively. The major isoprenoid quinone of AIST was ubiquinone 8 (Q-8). Predominant cellular fatty acids were iso-C17 : 0, iso-C15 : 0 and summed feature 9. The genomic DNA G+C content was 45.8 mol%. It is concluded that AIST represents a novel species of the genus Aliidiomarina , and the name Aliidiomarina shirensis sp. nov. is herein proposed for it. The type strain is AIST ( = JCM 17761T = BCRC 80327T). Based on its fatty acid profile and our phylogenetic analysis, we propose that Idiomarina maris be transferred to the genus Aliidiomarina .

Sterol binding by methyl-β-cyclodextrin and nystatin--comparative analysis of biochemical and physiological consequences for plants

The dependence of membrane function on its sterol component has been intensively studied with model lipids and isolated animal membranes, but to a much lesser extent with plant membranes. Depleting membrane sterols could be predicted to have a strong effect on membrane activity and have harmful physiological consequences. In this study, we characterized membrane lipid composition, membrane permeability for ions, some physiological parameters, such as H2O2 accumulation, formation of autophagosomal vacuoles, and expression of peroxidase and autophagic genes, and cell viability in the roots of wheat (Triticum aestivum L.) seedlings in the presence of two agents that specifically bind to endogenous sterols. The polyene antibiotic nystatin binds to endogenous sterols, forming so-called 'nystatin pores' or 'channels' in the membrane, and methyl-β-cyclodextrin has the capacity to sequester sterols in its hydrophobic core. Unexpectedly, although application of both methyl-β-cyclodextrin and nystatin reduced the sterol content, their effects on membrane permeability, oxidative status and autophagosome formation in roots differed dramatically. For comparison, we also tested the effects of the antibiotic gramicidin S, which does not bind to sterols but forms nonspecific channels in the membrane. Gramicidin S considerably increased membrane permeability, caused oxidative stress, and reduced cell viability. Our results suggest that a decrease in the sterol content is, in itself, not sufficient to have deleterious effects on a cell. The disturbance of membrane integrity, rather than the decrease in the sterol content, is responsible for the toxicity of sterol-binding compounds.

Effects of sterol-binding agent nystatin on wheat roots: the changes in membrane permeability, sterols and glycoceramides

Plant sterols are important multifunctional lipids, which are involved in determining membrane properties. Biophysical characteristics of model lipid and isolated animal membranes with altered sterol component have been intensively studied. In plants however, the precise mechanisms of involvement of sterols in membrane functioning remain unclear. In present work the possible interactions between sterols and other membrane lipids in plant cells were studied. A useful experimental approach for elucidating the roles of sterols in membrane activity is to use agents that specifically bind with endogenous sterols, for example the antibiotic nystatin. Membrane characteristics and the composition of membrane lipids in the roots of wheat (Triticum aestivum L.) seedlings treated with nystatin were analyzed. The application of nystatin greatly increased the permeability of the plasma membrane for ions and SH-containing molecules and decreased the total sterol level mainly as a consequence of a reduction in the amount of β-sitosterol and campesterol. Dynamic light-scattering was used to confirm the in vitro formation of stable complexes between nystatin and β-sitosterol or cholesterol. Sterol depletion was accompanied by a significant rise in total glycoceramide (GlCer) content after 2h treatment with nystatin. Analysis of the GlCer composition using mass spectrometry with electrospray ionization demonstrated that nystatin induced changes in the ratio of molecular species of GlCer. Our results suggest that changes in the sphingolipid composition can contribute to the changes in plasma membrane functioning induced by sterol depletion.

Litoreibacter albidus gen. nov., sp. nov. and Litoreibacter janthinus sp. nov., members of the class Alphaproteobacteria isolated from the seashore

Two Gram-negative, strictly aerobic, non-motile bacteria designated strains KMM 3851T and KMM 3842T were respectively isolated from a marine snail specimen (Umbonium costatum) and from surrounding sediments collected simultaneously from the shore of the Sea of Japan. Phylogenetic analysis based on 16S rRNA gene sequences showed that strains KMM 3851T and KMM 3842T were affiliated with the Roseobacter lineage of the class Alphaproteobacteria as a separate phylogenetic line adjacent to the members of the genus Thalassobacter. These novel isolates shared 98.5 % 16S rRNA gene sequence similarity and 15 % DNA–DNA relatedness. The major isoprenoid quinone of both strains was Q-10 and polar lipids consisted of phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and aminophospholipids. In addition, strain KMM 3851T contained two unknown lipids, whereas strain KMM 3842T contained diphosphatidylglycerol. Fatty acid analysis revealed C18 : 1 ω7c and C16 : 0 as major components and small amounts of C18 : 2. The DNA G+C contents were 60.4 mol% (KMM 3851T) and 58.5 mol% (KMM 3842T). Based on distinctive phenotypic characteristics, DNA–DNA hybridization data and phylogenetic distance, strains KMM 3851T and KMM 3842T should be classified as representatives of two novel species in a new genus, Litoreibacter gen. nov., with the type species Litoreibacter albidus sp. nov. (type strain KMM 3851T =NRIC 0773T =JCM 16493T) and a second species Litoreibacter janthinus sp. nov. (type strain KMM 3842T =NRIC 0772T =JCM 16492T).

Arenicella xantha gen. nov., sp. nov., a gammaproteobacterium isolated from a marine sandy sediment

A Gram-negative, aerobic, yellow-pigmented, rod-shaped, non-motile bacterium, strain KMM 3895T, was isolated from a marine sandy sample collected offshore from the Sea of Japan. Phylogenetic analysis based on the 16S rRNA gene sequence placed strain KMM 3895T in the class Gammaproteobacteria, forming a separate branch, sharing 89.5 % sequence similarity with Nitrincola lacisaponensis 4CAT and 88–87 % similarity with the other members of the cluster, including members of Kangiella, Spongiibacter, Alcanivorax and Microbulbifer. The major isoprenoid quinone was Q-8. Polar lipids consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, aminophospholipid and an unknown phospholipid. Fatty acid analysis revealed C16 : 1 ω7, iso-C16 : 0, iso-C18 : 0 and C18 : 1 ω7 as dominant components. The DNA G+C content was determined to be 48.1 mol%. Based on its unique phenotypic characteristics and phylogenetic distance, the marine coastal sediment isolate KMM 3895T should be classified as a representative of a novel genus and species, for which the name Arenicella xantha gen. nov., sp. nov. is proposed. The type strain of Arenicella xantha is KMM 3895T (=NRIC 0759T =JCM 16153T).

Marinicella litoralis gen. nov., sp. nov., a gammaproteobacterium isolated from coastal seawater

A Gram-negative, aerobic, greyish–yellowish-pigmented, stenohaline, rod-shaped, non-motile bacterium, strain KMM 3900T, was isolated from a coastal seawater sample collected from the Sea of Japan. Based on phylogenetic analysis, strain KMM 3900T was positioned within the Gammaproteobacteria on a separate branch adjacent to members of the genera Reinekea and Kangiella, sharing less than 88 % 16S rRNA gene sequence similarity with all recognized species of the Gammaproteobacteria. The major isoprenoid quinone was Q-8. Polar lipids consisted of phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and two unknown phospholipids. Fatty acid analysis revealed iso-C15 : 0, C16 : 1 ω7c and C16 : 0 as the dominant components. The DNA G+C content was 43.8 mol%. Based on its unique phenotypic characteristics and phylogenetic remoteness, marine isolate KMM 3900T is considered to represent a novel genus and species, for which the name Marinicella litoralis gen. nov., sp. nov. is proposed. The type strain of Marinicella litoralis is KMM 3900T (=NRIC 0758T =JCM 16154T).

Celeribacter neptunius gen. nov., sp. nov., a new member of the class Alphaproteobacteria

A whitish Gram-negative, motile, aerobic bacterium, designated strain H 14T, was isolated from seawater collected at St Kilda beach in Port Phillip Bay, Melbourne, Australia. Analysis of 16S rRNA gene sequences revealed that the organism belonged to the Roseobacter lineage of the class Alphaproteobacteria, forming a distinct evolutionary lineage at the genus level. Strain H 14T was distantly related to the genera Nautella, Ruegeria and Pseudoruegeria (family Rhodobacteraceae). Strain H 14T was unable to degrade gelatin, casein, chitin, agar and starch, did not produce any carotenoids, did not possess bacteriochlorophyll a and had a limited ability to utilize carbon sources. Strain H 14T grew with concentrations of 1–8 % (w/v) NaCl and over a temperature range of 5–35 °C. Phosphatidylglycerol was the major phospholipid (90 %); phosphatidylcholine (7.9 %) and phosphatidylethanolamine (2.0 %) were present in minor quantities. The predominant fatty acids were C18 : 1 ω7c (82.4 %), C18 : 1 ω9c (5.1 %) and C18 : 0 (3.8 %). The DNA G+C composition for strain H 14T was 59.1 mol%. Based on the results of physiological, biochemical, chemotaxonomic and phylogenetic investigations, a new genus, Celeribacter gen. nov., with the type species Celeribacter neptunius sp. nov. is proposed. The type strain of the type species is H 14T (=KMM 6012T=CIP 109922T).

Cocleimonas flava gen. nov., sp. nov., a gammaproteobacterium isolated from sand snail (Umbonium costatum)

A Gram-stain-negative, aerobic, yellow-pigmented, heterotrophic, sulfur-oxidizing, non-motile, rod-shaped bacterium, designated KMM 3898(T), was isolated from an internal tissue of the sand snail Umbonium costatum, collected from the shallow sediments of the Sea of Japan. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain KMM 3898(T) formed a distinct phylogenetic lineage within the class Gammaproteobacteria and was most closely related to Leucothrix mucor DSM 2157(T) (89.2 % 16S rRNA gene sequence similarity) and members of the genus Thiothrix (86.7-88.5 %). Chemotaxonomically, strain KMM 3898(T) contained the isoprenoid quinone Q-8, the polar lipids phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and an unknown phospholipid and the fatty acids C(18 : 1)ω7c, C(16 : 1)ω7c and C(16 : 0) as predominant components (>10 %). The DNA G+C content of strain KMM 3898(T) was 43.4 mol%. On the basis of phenotypic features and phylogenetic analysis, strain KMM 3898(T) represents a novel genus and species, for which the name Cocleimonas flava gen. nov., sp. nov. is proposed. The type strain is KMM 3898(T) (=NRIC 0757(T) =JCM 16494(T)).

Umboniibacter marinipuniceus gen. nov., sp. nov., a marine gammaproteobacterium isolated from the mollusc Umbonium costatum from the Sea of Japan

Two bacterial strains, KMM 3891(T) and KMM 3892, were isolated from internal tissues of the marine mollusc Umbonium costatum collected from the Sea of Japan. The novel isolates were Gram-negative, aerobic, faint pink-reddish-pigmented, rod-shaped, non-motile, stenohaline and psychrotolerant bacteria that were unable to degrade most tested complex polysaccharides. Polar lipids consisted of phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. Fatty acid analysis revealed C(17 : 1)omega6c, C(17 : 0), C(16 : 0) and C(16 : 1)omega7c as the dominant components. The major isoprenoid quinone was Q-7. The DNA G+C content of strain KMM 3891(T) was 51.7 mol%. According to phylogenetic analysis of 16S rRNA gene sequences, strains KMM 3891(T) and KMM 3892 were positioned within the Gammaproteobacteria as a separate branch, sharing <93 % sequence similarity to their phylogenetic relatives including Saccharophagus degradans, Microbulbifer species, Endozoicomonas elysicola, Simiduia agarivorans and Teredinibacter turnerae. Based on phenotypic characterization and phylogenetic distance, the novel marine isolates KMM 3891(T) and KMM 3892 represent a new genus and species, for which the name Umboniibacter marinipuniceus gen. nov., sp. nov. is proposed. The type strain of Umboniibacter marinipuniceus is KMM 3891(T) (=NRIC 0753(T) =JCM 15738(T)).

Pseudomonas marincola sp. nov., isolated from marine environments

An aerobic, Gram-negative, motile, non-pigmented bacterium, strain KMM 3042(T), isolated from a deep-sea brittle star in the Fiji Sea, was subjected to a polyphasic taxonomic study. Phylogenetic analysis based on 16S rRNA gene sequences revealed marine Mn(II)-oxidizing isolate S185-2B as the closest neighbour of strain KMM 3042(T) (99.9 % sequence similarity). The two strains formed a distinct lineage within the genus Pseudomonas adjacent to the members of the Pseudomonas borbori cluster, sharing highest sequence similarity of 97.4 and 97.0 %, respectively, with P. borbori DSM 17834(T) and Pseudomonas flavescens DSM 12071(T). The DNA-DNA hybridization value (71 %) between strains KMM 3042(T) and S185-2B confirmed their assignment to the same species. On the basis of phylogenetic analysis, DNA-DNA hybridization and physiological and biochemical characterization, strains KMM 3042(T) and S185-2B should be assigned to a novel species of the genus Pseudomonas, for which the name Pseudomonas marincola sp. nov. is proposed. The type strain is KMM 3042(T) (=NRIC 0729(T) =JCM 14761(T)).

Seasonal changes of fatty acid composition and thermotropic behavior of polar lipids from marine macrophytes

Major glyco- and phospholipids as well as betaine lipid 1,2-diacylglycero-O-4'-(N,N,N-tri-methyl)-homoserine (DGTS) were isolated from five species of marine macrophytes harvested in the Sea of Japan in summer and winter at seawater temperatures of 20-23 and 3 degrees C, respectively. GC and DSC analysis of lipids revealed a common increase of ratio between n-3 and n-6 polyunsaturated fatty acids (PUFAs) of polar lipids from summer to winter despite their chemotaxonomically different fatty acid (FA) composition. Especially, high level of different n-3 PUFAs was observed in galactolipids in winter. However, the rise in FA unsaturation did not result in the lowering of peak maximum temperature of phase transition of photosynthetic lipids (glycolipids and phosphatidylglycerol (PG)) in contrast to non-photosynthetic ones [phosphatidylcholine (PC) and phosphatidylethanolamine (PE)]. Different thermotropic behavior of these lipid groups was accompanied by higher content of n-6 PUFAs from the sum of n-6 and n-3 PUFAs in PC and PE compared with glycolipids and PG in both seasons. Seasonal changes of DSC transitions and FA composition of DGTS studied for the first time were similar to PC and PE. Thermograms of all polar lipids were characterized by complex profiles and located in a wide temperature range between -130 and 80 degrees C, while the most evident phase separation occurred in PGs in both seasons. Polarizing microscopy combined with DSC has shown that the liquid crystal - isotropic melt transitions of polar lipids from marine macrophytes began from 10 to 30 degrees C mostly, which can cause the thermal sensitivity of plants to superoptimal temperatures in their environment.

Cellular responses of microcolonial rock fungi to long-term desiccation and subsequent rehydration

Melanised rock-inhabiting fungi are astonishingly resistant to environmental stresses. Also known as micro-colonial fungi (MCF), they are ubiquitous and even colonise bare rocks in deserts. To survive in nutrient poor and extremely stressful conditions, MCF have reduced morphogenetic complexity to a minimum, and rely on a broad spectrum of stress protection mechanisms. Although visual signs of carotenoid presence are masked by heavily melanised black cell-walls, we were able to isolate and characterise a variety of carotenoids (ss-carotene, zeta-carotene, phytoene, torularhodin and torulene) in the rock-inhabiting, relatively fast-growing strain A95. The desiccation/rehydration stress response was used to measure the ability of A95 to adapt to slow or fast changes in external conditions. Revival of MCF after prolonged desiccation and rehydration was documented by biochemical (analyses of lipids and protective pigments), cultivation, and microscopic methods. Survival of MCF is enhanced when desiccation is rapid and mycostasis is instant rather than following prolonged periods of low metabolic activity.

Marixanthomonas ophiurae gen. nov., sp. nov., a marine bacterium of the family Flavobacteriaceae isolated from a deep-sea brittle star

An aerobic, Gram-negative, non-motile, yellow-pigmented bacterium, strain KMM 3046T, was isolated from a deep-sea brittle star from the Fiji Sea and was subjected to a polyphasic taxonomic analysis. Strain KMM 3046T grew at 5–32 °C and in the presence of 1–12 % (w/v) NaCl. It contained MK-6 as the predominant menaquinone and 3-OH i16 : 0, 3-OH i17 : 0 and 3-OH a17 : 0 as the major fatty acids. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain KMM 3046T forms a distinct evolutionary lineage within the family Flavobacteriaceae (phylum Bacteroidetes), displaying 92.3–91.9 % sequence similarity with respect to Salegentibacter species. On the basis of the phenotypic and phylogenetic data, strain KMM 3046T represents a novel genus and species of the family Flavobacteriaceae, for which the name Marixanthomonas ophiurae gen. nov., sp. nov. is proposed. The type strain of Marixanthomonas ophiurae is KMM 3046T (=NRIC 0684T=JCM 14121T).

Mesonia mobilis sp. nov., isolated from seawater, and emended description of the genus Mesonia

The taxonomic position of a novel marine, heterotrophic, strictly aerobic, gliding and yellow-pigmented bacterium, designated strain KMM 6059T, was determined. 16S rRNA gene sequence analysis revealed that this strain represents a member of the genus Mesonia. Phenotypic and chemotaxonomic data showed that the isolate represents a novel species of the genus Mesonia, for which the name Mesonia mobilis sp. nov. is proposed. The type strain is KMM 6059T (=KCTC 12708T=LMG 23670T). An emended description of the genus Mesonia based on the new data is also given.

Zobellella denitrificans gen. nov., sp. nov. and Zobellella taiwanensis sp. nov., denitrifying bacteria capable of fermentative metabolism

Two denitrifying strains of heterotrophic, facultatively anaerobic bacteria, designated ZD1T and ZT1T, were isolated from sediment samples collected from mangrove ecosystems in Taiwan. The isolates were Gram-negative. Cells grown in broth cultures were straight rods that were motile by means of a single polar flagellum. The isolates grew optimally in 1–3 % NaCl, but NaCl was not an absolute requirement for growth; only strain ZT1T grew in 13–14 % NaCl. Both isolates grew between 10 and 45 °C, with optimum growth at 30–35 °C. They were capable of anaerobic growth by denitrifying metabolism using nitrate or nitrous oxide as terminal electron acceptors or, alternatively, by fermenting glucose, sucrose or mannitol as substrates. C18 : 1 ω7c was the most abundant fatty acid (32.6–35.7 %). The other major fatty acids included C16 : 1 ω7c (27.5–29.4 %) and C16 : 0 (20.1–22.0 %). The two isolates had 16S rRNA gene sequence similarity of 96.8 % and shared 94.1–96.8 % sequence similarity with the most closely related species, Oceanimonas doudoroffii, Oceanimonas baumannii, Oceanimonas smirnovii and Oceanisphaera litoralis. They could be distinguished from these species in that they were capable of fermentative metabolism, had relatively high DNA G+C contents (62.0–64.0 mol%) and contained C18 : 1 ω7c instead of C16 : 1 ω7c as the most abundant fatty acid. Characterization data accumulated in this study revealed that the two denitrifying isolates could be classified as representatives of two novel species in a new genus, Zobellella gen. nov., with Zobellella denitrificans sp. nov. (type strain ZD1T=BCRC 17493T=JCM 13380T) as the type species and Zobellella taiwanensis sp. nov. (type strain ZT1T=BCRC 17494T=JCM 13381T) as a second species.

Loktanella agnita sp. nov. and Loktanella rosea sp. nov., from the north-west Pacific Ocean

One whitish and four pinkish strains of Gram-negative, non-motile, aerobic bacteria were isolated from sea-water and sediment samples collected in Chazhma Bay (Sea of Japan, Pacific Ocean). Analysis of 16S rRNA gene sequences revealed that these strains belonged to the ‘Alphaproteobacteria’, having highest sequence similarity of about 94–97 % with species of the genus Loktanella. None of the strains degraded gelatin, casein, chitin, agar, DNA or starch and they had limited ability to utilize carbon sources. The four pinkish strains, Fg36T, Fg1, Fg116 and Fg117, degraded Tween 80. Sea-water strain R10SW5T grew at 3–6 % NaCl and a temperature range of 8–35 °C, whilst strains Fg36T, Fg1, Fg116 and Fg117 grew at NaCl concentrations of 1–12 % and a temperature range of 4–35 °C. Phosphatidylglycerol (58/79 %), diphosphatidylglycerol (11/6 %) and phosphatidylcholine (28/22 %) were the major phospholipids. The predominant fatty acids were 16 : 0 (12·2/8·6 %) and 18 : 1ω7 (76·6/68·4 %). The DNA G+C content of strain R10SW5T was 59·1 mol% and those of the four pinkish strains ranged from 60·5 to 61·8 mol%. Based on the results of phenotypic, genotypic, chemotaxonomic and phylogenetic investigation, two novel species, Loktanella agnita sp. nov. and Loktanella rosea sp. nov., are proposed. The type strains are R10SW5T (=KMM 3788T=CIP 107883T) and Fg36T (=KMM 6003T=CIP 107851T=LMG 22534T), respectively.

Pseudomonas pachastrellae sp. nov., isolated from a marine sponge

Two Gram-negative, non-fermentative, non-denitrifying, non-pigmented, rod-shaped bacteria that were motile by means of polar flagella, designated strains KMM 330(T) and KMM 331, were isolated from a deep-sea sponge specimen and subjected to a polyphasic taxonomic study. The new isolates exhibited 16S rRNA gene sequence similarity of 99.9 %, and their mean level of DNA-DNA relatedness was 82 %. Phylogenetic analysis based on their 16S rRNA gene sequences placed the strains within the genus Pseudomonas as an independent deep clade. Strain KMM 330(T) shared highest sequence similarity (96.3 %) with each of Pseudomonas fulva NRIC 0180(T), Pseudomonas parafulva AJ 2129(T) and Pseudomonas luteola IAM 13000(T); sequence similarity to other recognized species of the genus Pseudomonas was below 95.7 %. The marine sponge isolates KMM 330(T) and KMM 331 could be distinguished from the other recognized Pseudomonas species based on a unique combination of their phenotypic characteristics, including growth in 8 or 10 % NaCl, the absence of pigments, the inability to denitrify and lack of carbohydrate utilization. On the basis of phylogenetic analysis, physiological and biochemical characterization, strains KMM 330(T) and KMM 331 should be classified as a novel species of the genus Pseudomonas, for which the name Pseudomonas pachastrellae sp. nov. is proposed. The type strain is KMM 330(T) (=JCM 12285(T)=NRIC 0583(T)=CCUG 46540(T)).

Alteromonas addita sp. nov

On the basis of phenotypic, genotypic characteristics and analysis of 16S rRNA gene sequences, a novel species belonging to the genus Alteromonas is described. A non-pigmented, motile, Gram-negative bacterium designated R10SW13T was isolated from sea water samples collected in Chazhma Bay (Sea of Japan, Pacific Ocean). The novel organism mainly grew between 4 °C and 37 °C, was neutrophilic and slightly halophilic, tolerating up to 10 % NaCl. Strain R10SW13T was haemolytic and was able to degrade starch and Tween 80 and to degrade gelatin and agar weakly, but did not degrade casein. Phosphatidylethanolamine (44·3±0·9 %) and phosphatidylglycerol (55·7±0·9 %) were the predominant phospholipids. The major fatty acids formed were typical for the genus Alteromonas, including 16 : 0, 16 : 1ω-7 and 18 : 1ω-7. The G+C content of the DNA was 43·4 mol%. DNA–DNA hybridization experiments showed 38–53 % binding with the DNAs of type strains of phylogenetically related species of the genus Alteromonas, namely: Alteromonas macleodii, Alteromonas marina, Alteromonas stellipolaris, Alteromonas litorea, ‘Alteromonas macleodii subsp. fijiensis’ and ‘Alteromonas infernus’. Based on these results, a novel species, Alteromonas addita sp. nov., is proposed, with strain R10SW13T (=KMM 3600T=KCTC 12195T=LMG 22532T) as the type strain.

Algibacter lectus gen. nov., sp. nov., a novel member of the family Flavobacteriaceae isolated from green algae

Three strains of the marine, gliding, pigmented, facultatively anaerobic, heterotrophic, Gram-negative bacteria were isolated from the green algae Acrosiphonia sonderi (Kütz) Kornm and Ulva fenestrata Ruprecht inhabiting the Sea of Japan. 16S rDNA sequence analysis indicated that the strains were members of the family Flavobacteriaceae, in which they occupied separate lineages. The predominant cellular fatty acids were i15 : 0, a15 : 0, i15 : 1, 15 : 0, 15 : 1omega6c, i15 : 0 3-OH and i17 : 0 3-OH. The DNA base compositions were 31-33 mol% G+C. Based on the phenotypic, genotypic, chemotaxonomic and phylogenetic analyses, the novel bacteria should be placed in a novel taxon as Algibacter lectus gen. nov., sp. nov. with type strain KMM 3902G (=KCTC 12103T=DSM 15365T).

The impact of abiotic factors (temperature and glucose) on physicochemical properties of lipids from Yersinia pseudotuberculosis

The impact of the availability of glucose in nutrition medium and growth temperature on the composition and thermotropic behavior of lipids from Yersinia pseudotuberculosis (Enterobacteriaceae) was studied. Y. pseudotuberculosis was grown in nutrition broth (NB) with/without glucose at 8 and 37 degrees C, corresponding to the temperatures of saprophytic and parasitic phases of this bacterium life. The decrease of phosphatidylethanolamine, phosphatidylglycerol and unsaturated fatty acids and the parallel increase of lysophosphatidylethanolamine and diphosphatidylglycerol and saturated and cyclopropane acids were the most significant changes with temperature in bacterial phospholipid (PL) classes and fatty acids, respectively. Glucose did not effect the direction of temperature-induced changes in the contents of PLs, fatty acids, however it enhanced (for PLs) or diminished (for fatty acids) intensity of these changes. The thermally induced transitions of lipids were studied by differential scanning calorimetry (DSC). It was revealed that the addition of glucose to NB induced a sharp shift of DSC thermograms to lower temperatures in the "warm" variants of bacteria. The peak maximum temperature (Tmax) of thermal transitions dropped from 50 to 26 degrees C that is the optimal growth temperature of Y. pseudotuberculosis. Tmax of total lipids of the cells grown at 8 degrees C without glucose in NB was equal to growth temperature that corresponded to the classical mechanism of homeoviscous adaptation of bacteria. An addition of glucose to NB at this growth temperature caused the subsequent reduction of Tmax to -8 degrees C, while the temperature ranges of thermograms were not substantially changed. So, not only the temperature growth of bacteria, but also the presence of glucose in NB can modify the physical state of lipids from Y. pseudotuberculosis. In this case, both factors affect additively. It is suggested that glucose influences some membrane-associated proteins and then the fluidity of lipid matrix through temperature-inducible genes.

Formosa algae gen. nov., sp. nov., a novel member of the family Flavobacteriaceae

Four light-yellow-pigmented, Gram-negative, short-rod-shaped, non-motile isolates were obtained from enrichment culture during degradation of the thallus of the brown alga Fucus evanescens. The isolates studied were chemo-organotrophic, alkalitolerant and mesophilic. Polar lipids were analysed and phosphatidylethanolamine was the only phospholipid identified. The predominant cellular fatty acids were 15 : 0, i15 : 0, ai15 : 0, i15 : 1 and 15 : 1(n-6). The DNA G+C contents of the four strains were 34.0-34.4 mol%. The level of DNA relatedness of the four isolates was conspecific (88-98 %), indicating that they belong to the same species. The 16S rDNA sequence of strain KMM 3553(T) was determined. Phylogenetic analysis revealed that KMM 3553(T) formed a distinct phyletic line in the phylum Bacteroidetes, class Flavobacteria in the family Flavobacteriaceae and that, phylogenetically, this strain could be placed almost equidistant from the genera Gelidibacter and Psychroserpens (16S rRNA gene sequence similarities of 94 %). On the basis of significant differences in phenotypic and chemotaxonomic characteristics, it is suggested that the isolates represent a novel species in a new genus; the name Formosa algae gen. nov., sp. nov. is proposed. The type strain is KMM 3553(T) (=CIP 107684(T)).

Fatty acid composition of individual polar lipid classes from marine macrophytes

Major glycolipids [monogalactosyldiacylglycerol (MGDG), digalactosyldiacylglycerol (DGDG), sulfoquinovosyldiacylglycerol (SQDG)) and phospholipids (phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylglycerol (PG)] as well as betaine lipid 1,2-diacylglycero-O-4'-(N,N,N-tri-methyl)-homoserine (DGTS) were isolated from Anfeltia tobuchiensis (Rhodophyta), Laminaria japonica, Sargassum pallidum (Phaeophyta), Ulva fenestrata (Chlorophyta) and Zostera marina (Embriophyta), harvested in the Sea of Japan. GC analysis of their fatty acid (FA) composition revealed that the n-6 polyunsaturated FAs (PUFAs) shared the most part of the sum of n-6 and n-3 PUFAs in PC and PE compared with glycolipids and PG. In algae, it was related to the prevalence of 20:4n-6 over 20:5n-3 in non-photosynthetic lipids. Percentage of n-6 PUFAs as well as the sum of n-3 and n-6 PUFAs decreased in the following sequence: PC-->PE-->PG. The saturation increased in the lines of MGDG-->DGDG-->SQDG and PC-->PE-->PG. PG was close to SQDG by the level of saturation. Distribution of C(18) and C(20) PUFAs in polar lipids depended on taxonomic position of macrophytes. Balance between C(18) and C(20) PUFAs was preferably shifted to the side of C(20) PUFAs in PC and PE that was observed in contrast to glycolipids and PG from L. japonica containing both series of FAs. The set of major FAs of polar lipid classes can essentially differ from each other and from total lipids of macrophytes. For example, MGDG was found to accumulate characteristic fatty acids 16:4n-3, 16:3n-3, 18:3n-6 and 18:4n-3, 20:3n-6 in U. fenestrata, Z. marina, L. japonica and S. pallidum, respectively.

Phospholipid composition of human sperm and seminal plasma in relation to sperm fertility

The phospholipid and fatty acid composition of sperm was studied in 8 healthy and 16 infertile men. Infertile men randomly formed from the patients with normal semen parameters according to WHO criterion. Therefore, all semen parameters of infertile patients were similar to the same characteristics of the semen of healthy men, except the abnormal forms. The amount of abnormal forms in infertile men was significantly higher than in healthy men. Sperm from infertile men show a drastic loss of phosphatidyl ethanolamine. At the same time, the significant increase of phosphatidyl serine in the sperm and seminal plasma of sterile patients was found. Lysophosphatidyl serine in the sperm of the infertile men was detected. Fatty acid composition of the semen of infertile men was altered. The levels of stearic and n-3 polyunsaturated fatty acids (eicosopentaenoic and docosahexaenoic acids) was dramatically lowered, but the values of some n-6 polyunsaturated fatty acids (linolenic and docosatetraenoic) acids increased. There was significant positive correlation between docosahexaenoic acid and sperm motility (r = .82, p < .001) and negative correlation between linolenic acid and spermatozoa motility (r = -0.58. p < .05). Infertility of men with normal semen quality can originate from the disorder of sperm lipid metabolism. The drastic loss of phosphatidyl ethanolamine and n-3 polyunsaturated fatty acids with simultaneous enhancement of phosphatidyl serine and some n-6 polyunsaturated fatty acids in sperm could be an important cause of male infertility.

Mutual influence of plasmid profile and growth temperature on the lipid composition of Yersinia pseudotuberculosis bacteria

The effect of a 82 MDa plasmid or its 25 MDa DNA fragment and growth temperature on the qualitative and the quantitative fatty acid and phospholipid composition of Yersinia pseudotuberculosis cells has been examined. In the cold, plasmid-containing and plasmid-free strains failed to differ appreciably in the contents of phospholipid and fatty acid. The exceptions were an elevated proportion of diphosphatidylglycerine and a decreased fatty acid unsaturation index in the plasmidless cells and those harbouring an incomplete 57 MDa plasmid in comparison with the strain containing the 82 MDa plasmid. At 37 degrees C, the lack of the 82 MDa plasmid or its 25 MDa fragment gave rise to a phospholipid of unknown structure, led to a sharp decrease in phospholipid content, in PE amount in particular, with a concurrent increase in the quantities of CL and LPE, and with a reduction in index of fatty acid unsaturation. The 82 MDa plasmid seems to be associated with a cancelling a temperature-dependent regulation of lipid synthesis and as a result, both the 'cold' and the 'warm' variants of the plasmid-containing strain possessed basically the close related lipid contents. Changes in composition of the polar head groups of the membrane phospholipids and in the extent of fatty acid unsaturation were suggested to be connected with an antibiotic hypersensitivity revealed earlier in plasmid-free Y. pseudotuberculosis.

The effect of long-chain N-acylethanolamines on some membrane-associated functions of neuroblastoma C1300 N18 cells

As reported earlier (Gulaya, N.M., Vaskovsky, V.E., Vystosky, M.V., Volkov, G.L., Govseeva, N.N. and Artemenko, I.P. (1988) Ukr. Biochim. J. 60, 58-63), N-acylphosphatidylethanolamines (NAPE) and products of their catabolism, N-acylethanolamines (NAE), are present in the lipids of neuroblastoma C1300 N18 undifferentiated cells. The present paper describes the distribution of NAE added to culture medium of differentiated cells and its effect on the fast sodium channels and some other membrane characteristics. It is shown that NAE inhibits the destroying action of veratridine on membranes.