scholarly journals Lipoxygenase Pathways in Diatoms: Occurrence and Correlation with Grazer Toxicity in Four Benthic Species

Marine Drugs ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 66 ◽  
Author(s):  
Nadia Ruocco ◽  
Genoveffa Nuzzo ◽  
Giuliana d’Ippolito ◽  
Emiliano Manzo ◽  
Angela Sardo ◽  
...  

Oxygenated derivatives of fatty acids, collectively called oxylipins, are a highly diverse family of lipoxygenase (LOX) products well described in planktonic diatoms. Here we report the first investigation of these molecules in four benthic diatoms, Cylindrotheca closterium, Nanofrustulum shiloi, Cocconeis scutellum, and Diploneis sp. isolated from the leaves of the seagrass Posidonia oceanica from the Gulf of Naples. Analysis by hyphenated MS techniques revealed that C. closterium, N. shiloi, and C. scutellum produce several polyunsaturated aldehydes (PUAs) and linear oxygenated fatty acids (LOFAs) related to the products of LOX pathways in planktonic species. Diploneis sp. also produced other unidentified fatty acid derivatives that are not related to LOX metabolism. The levels and composition of oxylipins in the benthic species match their negative effects on the reproductive success in the sea urchin Paracentrotus lividus. In agreement with this correlation, the most toxic species N. shiloi revealed the same LOX pathways of Skeletonema marinoi and Thalassiosira rotula, two bloom-forming planktonic diatoms that affect copepod reproduction. Overall, our data highlight for the first time a major role of oxylipins, namely LOFAs, as info-chemicals for benthic diatoms, and open new perspectives in the study of the structuring of benthic communities.

2017 ◽  
Vol 10 (1) ◽  
pp. 92-99 ◽  
Author(s):  
Hércules Rezende Freitas

Polyunsaturated fatty acids (PUFAs) comprise about 35-40% of the total lipid content from green algaeChlorella, reaching up to 24% linoleic acid and 27% α-linolenic acid inC. vulgaris. Also, microalgae nutrient composition may be modulated by changes in the culture medium, increasing fatty acid and microelement concentrations in the algae biomass. PUFAs, such as α-linolenic (n-3) and linoleic (n-6) acids, as well as its derivatives, are considered essential for dietary consumption, and their ability to regulate body chemistry has been recently explored in depth. A balanced fatty acid consumption is shown to counteract the negative effects of western diets, such as chronic inflammation and glucose intolerance. In this brief commentary, technological and practical uses ofC. vulgarisare explored as means to improve dietary quality and, ultimately, human health.


2020 ◽  
Vol 8 (9) ◽  
pp. 661
Author(s):  
Davide Asnicar ◽  
Costanza Cappelli ◽  
Ahmad Safuan Sallehuddin ◽  
Nur Atiqah Maznan ◽  
Maria Gabriella Marin

Despite the widespread use of herbicide glyphosate in cultivation, its extensive runoff into rivers and to coastal areas, and the persistence of this chemical and its main degradation product (aminomethylphosphonic acid, AMPA) in the environment, there is still little information on the potential negative effects of glyphosate, its commercial formulation Roundup® and AMPA on marine species. This study was conducted with the aim of providing a comparative evaluation of the effects of glyphosate-based and its derived chemicals on the larval development of the sea urchin Paracentrotus lividus, thus providing new data to describe the potential ecotoxicity of these contaminants. In particular, the effects on larval development, growth and metabolism were assessed during 48 h of exposure from the time of egg fertilization. The results confirm that AMPA and its parent compound, glyphosate have similar toxicity, as observed in other marine invertebrates. However, interestingly, the Roundup® formulation seemed to be less toxic than the glyphosate alone.


Author(s):  
Mourad Guettaf ◽  
Gustavo A. San Martin ◽  
Patrice Francour

The spawning of Paracentrotus lividus has been determined on the basis of the annual gonad index cycle at three sites in the Algiers area presenting low, intermediate and strong hydrodynamism. Three biotopes (Posidonia oceanica beds, rocky substrate with photophilous algae and overgrazed rocky substrate) and two depths (1–3 m and 6–10 m) were considered at these sites, the sex-ratio was always strongly in favour of females (2:1 to 3:1). In all sites but one, there were marked differences in the gonad index and the spawning period between sites; the gonad index reached its maximum value at the site with the weakest hydrodynamism, and the minimum value at the site with the strongest hydrodynamism. Spawning took place in April–May and August–September at the site with the weakest hydrodynamism, in April–June and October–December at the site with intermediate hydrodynamism and only in winter at the site with maximum hydrodynamism. The coexistence, on regional scale, of these reproductive cycles might enable Paracentrotus lividus to compensate the mortality during planktonic larval phase by the fact that spawning of this sea urchin occurred in all seasons.


2004 ◽  
Vol 52 (3-4) ◽  
pp. 183-194 ◽  
Author(s):  
Ricardo Luiz Queiroz ◽  
Frederico Pereira Brandini ◽  
Franciane Maria Pellizzari

The composition and biomass of the microalgal community at the water-column/sediment interface on the continental shelf off Parana State (Brazil) were studied every 2 months during 1999. Samples for cell identification and determination of chlorophyll a were taken from the interface layer and at discrete depths up to 4 m above the sediment. Results showed a community mainly formed by benthic and planktonic diatoms >30 µm, benthic diatoms <30 µm and cyanobacteria. Cell densities were generally higher at the interface layer. Resuspension and sedimentation events seemed to be a paramount factor regulating the composition and biomass of these communities, and affected differently cells of different size classes. Cells >30 µm, which accounted for most of the pigment biomass, were resuspended from the interface after turbulent periods, and may take advantage of calm periods to stay and grow at the interface. Small benthic diatoms were more susceptible to wind-induced turbulence occurring in higher densities in the water column just above the water-sediment interface. A cyanobacterial bloom (Trichodesmiun) was observed at these bottom layers in the spring-summer periods.


2018 ◽  
Vol 30 (12) ◽  
pp. 1770 ◽  
Author(s):  
W. Chankeaw ◽  
Y. Z. Guo ◽  
R. Båge ◽  
A. Svensson ◽  
G. Andersson ◽  
...  

Elevated non-esterified fatty acids (NEFAs) are associated with negative effects on bovine theca, granulosa and oviductal cells but the effects of NEFAs on bovine endometrial epithelial cells (bEECs) are not as well documented. The objective of this study was to define the effects of NEFAs on bEECs. Postprimary bEECs were treated with 150, 300 or 500 µM of either palmitic acid (PA), stearic acid (SA) or oleic acid (OA) or a mixture of NEFAs (150 µM of each FA) or 0.5% final concentration of vehicle ethanol (control). Viability and proliferation of bEECs exposed to 150 µM of each NEFA or a mixture of NEFAs were unaffected. Increased lipid accumulation was found in all treated groups (P < 0.01). In cells exposed to 500 µM of each NEFA and 300 µM PA decreased cell viability (P < 0.001), proliferation (P < 0.05) and increased apoptosis (P < 0.05) were observed. Treatment with 500 µM OA, PA and SA had the strongest effects on cell viability, proliferation and apoptosis (P < 0.05). Treatment with PA and OA increased interleukin-6 (IL-6) concentrations (P < 0.05), whereas only the highest concentration of PA, OA and SA stimulated IL-8 production (P < 0.05). These results suggest that high concentrations of NEFAs may impair endometrial function with more or less pronounced effects depending on the type of NEFA and time of exposure.


2019 ◽  
Vol 83 (4) ◽  
pp. 349
Author(s):  
Inés Castejón-Silvo ◽  
Damià Jaume ◽  
Jorge Terrados

The functional importance of herbivory in seagrass beds is highly variable among systems. In Mediterranean seagrass meadows, macroherbivores, such as the fish Sarpa salpa and the sea urchin Paracentrotus lividus, have received most research attention, so published evidence highlights their importance in seagrass consumption. The role of small crustaceans in seagrass consumption remains less studied in the region. Herbivory on Posidonia oceanica seeds has not previously been reported. In turn, crustacean herbivory on P. oceanica leaves is broadly recognized, although the species feeding on the seagrass are mostly unknown (except for Idotea baltica). This work evaluates P. oceanica consumption by two species of amphipod crustaceans commonly found in seagrass meadows. Ampithoe ramondi and Gammarella fucicola actively feed on P. oceanica leaves and seeds. Both species preferred seeds to leaves only when the seed coat was damaged. This study provides the first direct evidence of consumption of P. oceanica seeds by the two named amphipod crustaceans, and confirms that they also consume leaves of this seagrass species.


Aquaculture ◽  
2018 ◽  
Vol 495 ◽  
pp. 13-20 ◽  
Author(s):  
Valerio Zupo ◽  
Francesca Glaviano ◽  
Davide Caramiello ◽  
Mirko Mutalipassi

Author(s):  
Alperen Koker ◽  
İlhami Okur ◽  
Sebnem Ozturkoglu-Budak ◽  
Hami Alpas

Dairy products include carbohydrates, protein, fatty acids, and different micronutrients, such as minerals and vitamins. Thermal treatment is generally used in dairy products to provide product safety and increase shelf life. But it can also lead to undesirable effects on dairy products such as protein denaturation, maillard reaction, and loss of vitamins. Non-thermal technology is an alternative method in the preservation of food products due to improving product safety and shelf life without any negative effects on food nutritional content. High hydrostatic pressure (HHP), pulsed electric field (PEF), ultrasound, cold plasma (CP), and pulsed light (PL) are the main non-thermal techniques that are used in the food industry. This chapter gives general principles of the non-thermal techniques, current applications in the dairy products, and recent advances in the dairy industry.


2014 ◽  
Vol 11 (14) ◽  
pp. 3729-3738 ◽  
Author(s):  
K. E. Larkin ◽  
A. J. Gooday ◽  
C. Woulds ◽  
R. M. Jeffreys ◽  
M. Schwartz ◽  
...  

Abstract. Foraminifera are an important component of benthic communities in oxygen-depleted settings, where they potentially play a significant role in the processing of organic matter. We tracked the uptake of a 13C-labelled algal food source into individual fatty acids in the benthic foraminiferal species Uvigerina ex. gr. semiornata from the Arabian Sea oxygen minimum zone (OMZ). The tracer experiments were conducted on the Pakistan margin during the late/post monsoon period (August–October 2003). A monoculture of the diatom Thalassiosira weisflogii was 13C-labelled and used to simulate a pulse of phytoplankton in two complementary experiments. A lander system was used for in situ incubations at 140 m water depth and for 2.5 days in duration. Shipboard laboratory incubations of cores collected at 140 m incorporated an oxystat system to maintain ambient dissolved oxygen concentrations and were terminated after 5 days. Uptake of diatoms was rapid, with a high incorporation of diatom fatty acids into foraminifera after ~ 2 days in both experiments. Ingestion of the diatom food source was indicated by the increase over time in the quantity of diatom biomarker fatty acids in the foraminifera and by the high percentage of 13C in many of the fatty acids present at the endpoint of both in situ and laboratory-based experiments. These results indicate that


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