Lipidomic signatures reveal seasonal shifts on the relative abundance of high-valued lipids from the brown algae Fucus vesiculosus

Fucus vesiculosus is an edible brown macroalga, with health benefits associated with its consumption and also a source of bioactive molecules. It is acknowledged that the biochemical composition of macroalgae changes when exposed to different environmental conditions occurring on different habitats, such as the water temperature, and light intensity. In the present study, the polar lipidome of Fucus vesiculosus was characterized for the first time using modern high-resolution HILIC-MS, and MS/MS approaches, to evaluate the phenotypic variability in two seasons of the year, e.g., winter and spring. A total of 187 molecular species were identified over eighteen classes of glycolipids, phospholipids and betaine lipids. Principal component analysis (PCA) multivariate statistical analysis and cluster analysis of polar lipid classes, polar lipid species and total fatty acids (FA) datasets, showed clustering according to the seasonal groups. While the lipid profile of Fucus vesiculosus harvested in the winter and spring yielded the same molecular species, the relative abundance of these species was significantly different. In the winter, changes were mainly due to the increased relative abundance of some molecular species of glycolipids and phospholipids, bearing octadeca(poly)enoic (18:3, 18:4) and eicosa(poly)enoic (20:4, 20:5) FA and betaine lipids species with short saturated FA (14:0) and polyunsaturated FA (PUFA). Importantly, glycolipids with n-3 PUFA and sulfolipids, have been reported to have important biological activities and therapeutic value. Overall, Fucus vesiculosus is a promising source of bioactive compounds that can be used as functional food or ingredients for human nutrition, feed, pharma, and cosmetic formulations. In this study, samples harvested in the winter season maximized yields of these bioactive components, when compared with samples harvested in the spring.publishe

Fussy Feeders: Phyllosoma Larvae of the Western Rocklobster (Panulirus cygnus) Demonstrate Prey Preference

The Western Rocklobster (Panulirus cygnus) is the most valuable single species fishery in Australia and the largest single country spiny lobster fishery in the world. In recent years a well-known relationship between oceanographic conditions and lobster recruitment has become uncoupled, with significantly lower recruitment than expected, generating interest in the factors influencing survival and development of the planktonic larval stages. The nutritional requirements and wild prey of the planktotrophic larval stage (phyllosoma) of P. cygnus were previously unknown, hampering both management and aquaculture efforts for this species. Ship-board feeding trials of wild-caught mid-late stage P. cygnus phyllosoma in the eastern Indian Ocean, off the coast of Western Australia, were conducted in July 2010 and August-September 2011. In a series of experiments, phyllosoma were fed single and mixed species diets of relatively abundant potential prey items (chaetognaths, salps, and krill). Chaetognaths were consumed in 2–8 times higher numbers than the other prey, and the rate of consumption of chaetognaths increased with increasing concentration of prey. The highly variable lipid content of the phyllosoma, and the fatty acid profiles of the phyllosoma and chaetognaths, indicated they were from an oligotrophic oceanic food chain where food resources for macrozooplankton were likely to be constrained. Phyllosoma fed chaetognaths over 6 days showed significant changes in some fatty acids and tended to accumulate lipid, indicating an improvement in overall nutritional condition. The discovery of a preferred prey for P. cygnus will provide a basis for future oceanographic, management and aquaculture research for this economically and ecologically valuable species

Potential use of fatty acid profiles of the adductor muscle of cockles (Cerastoderma edule) for traceability of collection site

Geographic traceability of seafood is key for controlling its quality and safeguarding consumers’ interest. The present study assessed if the fatty acid (FA) profile of the adductor muscle (AM) of fresh cockles (Cerastoderma edule) can be used to discriminate the origin of specimens collected in different bivalve capture/production areas legally defined within a coastal lagoon. Results suggest that this biochemical approach holds the potential to trace sampling locations with a spatial resolution <10 Km, even for areas with identical classification for bivalve production. Cockles further away from the inlet, i.e. in areas exposed to a higher saline variation, exhibited lower levels of saturated fatty acids, which are key for stabilizing the bilayer structure of cell membranes, and a higher percentage of polyunsaturated fatty acids, which enhance bilayer fluidity. Results suggest that the structural nature of the lipids present in the AM provides a stable fatty acid signature and holds potential for tracing the origin of bivalves to their capture/production areas

Residues of total and methyl mercury in some fishes and mussels of the Northern Adriatic Sea

Uzorci riba ·i školjaka Sjevernog Jadrana analizirani su na ostatke ukupne i metil žive. U svim uzorcima tkiva i organa dokazana je prisutnost ukupne i metil žive. Prosječna vrijednost metil žive u mišićima srdele (20,6 µg/kg), ugora (100,0 µg/kg), tune (225,0 µg/kg) i u dagnjama (15,7 µg/kg) ne premašuje zakonom u nas dopuštene količine. Ukupna živa u istim uzorcima iznosila je u srdeli 170 µg/kg, ugoru 570 µg/kg, tuni 1730 ug/kg, te dagnjama 56 µg/kg. Ove vrijednosti, osim u uzorku tune, nisu, također, iznad dopuštenih.Commercial fishes and mussels were collected in the Northern Adriatic Sea and analysed for total methyl mercury content. Total and methyl mercury were found to be present in all samples. The average total mercury concentrations in sardine, conger-eel, tuna and Mediterranean mussel were 170.0, 570.0, 1730.0 and 56.0 µg/kg respectively. Gas chromatography determination of methyl mercury showed average concentrations in sardine, conger-eel, tuna and Mediterranean mussel to be 20.6, 100.0, 225.0 and 15.7 µg/kg respectively. Total and methyl mercury concentrations were below the tolerance limit except for total mercury content in the tuna muscle tissue (1730 µg/kg)

Residues of total and methyl mercury in some fishes and mussels of the Northern Adriatic Sea

Uzorci riba ·i školjaka Sjevernog Jadrana analizirani su na ostatke ukupne i metil žive. U svim uzorcima tkiva i organa dokazana je prisutnost ukupne i metil žive. Prosječna vrijednost metil žive u mišićima srdele (20,6 µg/kg), ugora (100,0 µg/kg), tune (225,0 µg/kg) i u dagnjama (15,7 µg/kg) ne premašuje zakonom u nas dopuštene količine. Ukupna živa u istim uzorcima iznosila je u srdeli 170 µg/kg, ugoru 570 µg/kg, tuni 1730 ug/kg, te dagnjama 56 µg/kg. Ove vrijednosti, osim u uzorku tune, nisu, također, iznad dopuštenih.Commercial fishes and mussels were collected in the Northern Adriatic Sea and analysed for total methyl mercury content. Total and methyl mercury were found to be present in all samples. The average total mercury concentrations in sardine, conger-eel, tuna and Mediterranean mussel were 170.0, 570.0, 1730.0 and 56.0 µg/kg respectively. Gas chromatography determination of methyl mercury showed average concentrations in sardine, conger-eel, tuna and Mediterranean mussel to be 20.6, 100.0, 225.0 and 15.7 µg/kg respectively. Total and methyl mercury concentrations were below the tolerance limit except for total mercury content in the tuna muscle tissue (1730 µg/kg)

Compositional stability of sediment microbial communities during a seagrass meadow decline

The presence of seagrass shapes surface sediments and forms a specific environment for diverse and abundant microbial communities. A severe decline of Cymodocea nodosa, a widespread seagrass species in the Mediterranean Sea, has been documented. To characterise and assess thechanges in microbial community composition during the decline of a Cymodocea nodosa meadow, Illumina MiSeq sequencing of the V4 region of the 16S rRNA gene was performed. Samples of surface sedimentsfrom two sites, one without any vegetation and one with a declining Cymodocea nodosa meadow, were collected at monthly intervals from July 2017 to October 2018. Microbial communities were stratified by sediment depth and differed between the vegetated and the nonvegetated site. Although the Cymodocea nodosa meadow declined to a point where almost no leaves were present, no clear temporal succession in the community was observed. Taxonomic analysis revealed a dominance ofbacterial over archaeal sequences, with most archaeal reads classified as Nanoarchaeota, Thermoplasmatota, Crenarchaeota, and Asgardarchaeota. The bacterial community was mainly composedof Desulfobacterota, Gammaproteobacteria,Bacteroidota, Chloroflexi, Planctomycetota, and Campylobacterota. Our results show that sediment microbial communities are remarkably stable and may resist major disturbances such as seagrass meadow decline.</p

Superhydrophobic surface structures in thermoplastic polymers by interference lithography and thermal imprinting

We present a method to produce superhydrophobic surfaces in thermoplastic polymer substrates. The method involves the creation of a nickel stamp using a customized laser interference lithography technique and electroplating processes. This stamp is used to emboss sub-micrometer periodic structures into the thermoplastic. The modified surface is coated with a hydrophobic plasma-polymerized hexafluoropropene layer. Surfaces with different periodicity and relief depth were created. On the surface with the highest aspect ratio, advancing water contact angles of 167° were measured with a water contact angle hysteresis of below 5°

Superhydrophobic surface structures in thermoplastic polymers by interference lithography and thermal imprinting

We present a method to produce superhydrophobic surfaces in thermoplastic polymer substrates. The method involves the creation of a nickel stamp using a customized laser interference lithography technique and electroplating processes. This stamp is used to emboss sub-micrometer periodic structures into the thermoplastic. The modified surface is coated with a hydrophobic plasma-polymerized hexafluoropropene layer. Surfaces with different periodicity and relief depth were created. On the surface with the highest aspect ratio, advancing water contact angles of 167° were measured with a water contact angle hysteresis of below 5°