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International Journal of Molecular... May 2024While edible algae might seem low in fat, the lipids they contain are crucial for good health and preventing chronic diseases. This study introduces a binary matrix to...
While edible algae might seem low in fat, the lipids they contain are crucial for good health and preventing chronic diseases. This study introduces a binary matrix to analyze all the polar lipids in both macroalgae (Wakame-, Dulse-, and Nori- spp.) and microalgae (Spirulina-, and Chlorella-) using matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS). The key lies in a new dual matrix made by combining equimolar amounts of 1,5-diaminonaphthalene (DAN) and 9-aminoacridine (9AA). This combination solves the limitations of single matrices: 9AA is suitable for sulfur-containing lipids and acidic phospholipids, while DAN excels as an electron-transfer secondary reaction matrix for intact chlorophylls and their derivatives. By employing the equimolar binary matrix, a wider range of algal lipids, including free fatty acids, phospholipids, glycolipids, pigments, and even rare arsenosugarphospholipids were successfully detected, overcoming drawbacks related to ion suppression from readily ionizable lipids. The resulting mass spectra exhibited a good signal-to-noise ratio at a lower laser fluence and minimized background noise. This improvement stems from the binary matrix's ability to mitigate in-source decay effects, a phenomenon often encountered for certain matrices. Consequently, the data obtained are more reliable, facilitating a faster and more comprehensive exploration of algal lipidomes using high-throughput MALDI-MS/MS analysis.
Topics: Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Lipids; Seaweed; Microalgae; 2-Naphthylamine; Aminacrine; Pigments, Biological; Spirulina
PubMed: 38892117
DOI: 10.3390/ijms25115919 -
International Journal of Molecular... May 2024In this paper, the characteristics of 40 so far described virophages-parasites of giant viruses-are given, and the similarities and differences between virophages and... (Review)
Review
Virophages, Satellite Viruses, Virophage Replication and Its Effects and Virophage Defence Mechanisms for Giant Virus Hosts and Giant Virus Defence Systems against Virophages.
In this paper, the characteristics of 40 so far described virophages-parasites of giant viruses-are given, and the similarities and differences between virophages and satellite viruses, which also, like virophages, require helper viruses for replication, are described. The replication of virophages taking place at a specific site-the viral particle factory of giant viruses-and its consequences are presented, and the defence mechanisms of virophages for giant virus hosts, as a protective action for giant virus hosts-protozoa and algae-are approximated. The defence systems of giant viruses against virophages were also presented, which are similar to the CRISPR/Cas defence system found in bacteria and in Archea. These facts, and related to the very specific biological features of virophages (specific site of replication, specific mechanisms of their defensive effects for giant virus hosts, defence systems in giant viruses against virophages), indicate that virophages, and their host giant viruses, are biological objects, forming a 'novelty' in biology.
Topics: Giant Viruses; Satellite Viruses; Virophages; Virus Replication; Gene Silencing
PubMed: 38892066
DOI: 10.3390/ijms25115878 -
Polymers Jun 2024Poly(dimethylsiloxane) (PDMS) coatings are considered to be environmentally friendly antifouling coatings. However, the presence of hydrophobic surfaces can enhance the...
Poly(dimethylsiloxane) (PDMS) coatings are considered to be environmentally friendly antifouling coatings. However, the presence of hydrophobic surfaces can enhance the adhesion rate of proteins, bacteria and microalgae, posing a challenge for biofouling removal. In this study, hydrophilic polymer chains were synthesised from methyl methacrylate (MMA), Poly(ethylene glycol) methyl ether methacrylate (PEG-MA) and 3-(trimethoxysilyl) propyl methacrylate (TPMA). The crosslinking reaction between TPMA and PDMS results in the formation of a silicone-based amphiphilic co-network with surface reconstruction properties. The hydrophilic and hydrophobic domains are covalently bonded by condensation reactions, while the hydrophilic polymers migrate under water to induce surface reconstruction and form hydrogen bonds with water molecules to form a dense hydrated layer. This design effectively mitigates the adhesion of proteins, bacteria, algae and other marine organisms to the coating. The antifouling performance of the coatings was evaluated by assessing their adhesion rates to proteins (), bacteria ( and ) and algae (). The results show that the amphiphilic co-network coating (e.g., P-AM-15) exhibits excellent antifouling properties against protein, bacterial and microalgal fouling. Furthermore, an overall assessment of its antifouling performance and stability was conducted in the East China Sea from 16 May to 12 September 2023, which showed that this silicon-based amphiphilic co-network coating remained intact with almost no marine organisms adhering to it. This study provides a novel approach for the development of high-performance silicone-based antifouling coatings.
PubMed: 38891516
DOI: 10.3390/polym16111570 -
Plants (Basel, Switzerland) May 2024Plants and algae use light not only for driving photosynthesis but also to sense environmental cues and to adjust their circadian clocks via photoreceptors. Aureochromes...
Plants and algae use light not only for driving photosynthesis but also to sense environmental cues and to adjust their circadian clocks via photoreceptors. Aureochromes are blue-light-dependent photoreceptors that also function as transcription factors, possessing both a LOV and a bZIP domain. Aureochromes so far have only been detected in Stramenopile algae, which include the diatoms. Four paralogues of aureochromes have been identified in the pennate model diatom : PtAureo1a, 1b, 1c, and 2. While it was shown recently that diatoms have a diel rhythm, the molecular mechanisms and components regulating it are still largely unknown. Diel gene expression analyses of wild-type , a PtAureo1a knockout strain, and the respective PtAureo1 complemented line revealed that all four aureochromes have a different diel regulation and that PtAureo1a has a strong co-regulatory influence on its own transcription, as well as on that of other genes encoding different blue-light photoreceptors (CPF1, 2 and 4), proteins involved in photoprotection (Lhcx1), and specific bHLH transcription factors (RITMO1). Some of these genes completely lost their circadian expression in the PtAureo1a KO mutant. Our results suggest a major involvement of aureochromes in the molecular clock of diatoms.
PubMed: 38891274
DOI: 10.3390/plants13111465 -
Foods (Basel, Switzerland) Jun 2024This Special Issue (SI) of , entitled ", , ", was focused on algal organisms, both microalgae and macroalgae, which have recently been recognized as new, cost-effective,...
This Special Issue (SI) of , entitled ", , ", was focused on algal organisms, both microalgae and macroalgae, which have recently been recognized as new, cost-effective, and valuable sources of health-promoting nutrients and bioactive compounds with a full spectrum of activities and beneficial effects on health [...].
PubMed: 38890964
DOI: 10.3390/foods13111736 -
Foods (Basel, Switzerland) May 2024Algae are a booming resource in the food industry due to their several health benefits. This study assesses the impact of the combined use of selected macro- and...
Algae are a booming resource in the food industry due to their several health benefits. This study assesses the impact of the combined use of selected macro- and microalgae to improve the nutritional profile and the labeling of a vegetable cream by the introduction of nutrition and health claims. As macroalgae, two L., one natural (An) and one smoked (AnS), were selected for their high iodine concentration and flavor notes. A new strain of , golden (CvG), was selected as the microalgae, which is rich in proteins and has a neutral sensorial profile (golden color and mild flavor). In this study, two vegetable creams were compared. The control (CTRL) versus one enriched with a mixture of macroalgae and microalgae (CV-AN). Sensory, physicochemical, and functional properties of both vegetable creams were evaluated. The bioactivity assessed was the effect of iodine as a health claim and antioxidant and antihypertensive properties. CV-AN vegetable cream showed significantly higher values ( < 0.05) for protein content, iodine value, and antioxidant activity, with no significant differences ( > 0.05) in antihypertensive activity or sensory panel. The incorporation of these algae resulted in a vegetable cream with a better nutritional profile and sensory acceptability comparable to the control, offering protein and iodine source claims in the labeling.
PubMed: 38890879
DOI: 10.3390/foods13111651 -
Foods (Basel, Switzerland) May 2024Vitamins are essential organic compounds that vary widely in chemical structure and are vital in small quantities for numerous biochemical and biological functions. They... (Review)
Review
Vitamins are essential organic compounds that vary widely in chemical structure and are vital in small quantities for numerous biochemical and biological functions. They are critical for metabolism, growth, development and maintaining overall health. Vitamins are categorised into two groups: hydrophilic and lipophilic. Vitamin K (VK), a lipophilic vitamin, occurs naturally in two primary forms: phylloquinone (VK1), found in green leafy vegetables and algae, and Menaquinones (VK2), present in certain fermented and animal foods and widely formulated in VK supplements. This review explores the possible factors contributing to VK deficiency, including dietary influences, and discusses the pharmacological and therapeutic potential of supplementary VK2, examining recent global clinical studies on its role in treating diseases such as osteoporosis, osteoarthritis, rheumatoid arthritis, cardiovascular disease, chronic kidney disease, diabetes, neurodegenerative disorders and cancers. The analysis includes a review of published articles from multiple databases, including Scopus, PubMed, Google Scholar, ISI Web of Science and CNKI, focusing on human studies. The findings indicate that VK2 is a versatile vitamin essential for human health and that a broadly positive correlation exists between VK2 supplementation and improved health outcomes. However, clinical data are somewhat inconsistent, highlighting the need for further detailed research into VK2's metabolic processes, biomarker validation, dose-response relationships, bioavailability and safety. Establishing a Recommended Daily Intake for VK2 could significantly enhance global health.
PubMed: 38890875
DOI: 10.3390/foods13111646 -
Biology Letters Jun 2024Red coralline algae create abundant, spatially vast, reef ecosystems throughout our coastal oceans with significant ecosystem service provision, but our understanding of...
Red coralline algae create abundant, spatially vast, reef ecosystems throughout our coastal oceans with significant ecosystem service provision, but our understanding of their basic physiology is lacking. In particular, the balance and linkages between carbon-producing and carbon-sequestering processes remain poorly constrained, with significant implications for understanding their role in carbon sequestration and storage. Using dual radioisotope tracing, we provide evidence for coupling between photosynthesis (which requires CO) and calcification (which releases CO) in the red coralline alga (previously )-a marine ecosystem engineer widely distributed across Atlantic mid-high latitudes. Of the sequestered HCO , 38 ± 22% was deposited as carbonate skeleton while 39 ± 14% was incorporated into organic matter via photosynthesis. Only 38 ± 2% of the sequestered HCO was transformed into CO, and almost 40% of that was internally recycled as photosynthetic substrate, reducing the net release of carbon to 23 ± 3% of the total uptake. The calcification rate was strongly dependent on photosynthetic substrate production, supporting the presence of photosynthetically enhanced calcification. The efficient carbon-recycling physiology reported here suggests that calcifying algae may not contribute as much to marine CO release as is currently assumed, supporting a reassessment of their role in blue carbon accounting.
Topics: Photosynthesis; Rhodophyta; Calcification, Physiologic; Carbon; Carbon Dioxide; Carbon Cycle; Carbon Sequestration
PubMed: 38889774
DOI: 10.1098/rsbl.2023.0598 -
Plant Direct Jun 2024Eukaryotic cells are highly compartmentalized, requiring elaborate transport mechanisms to facilitate the movement of proteins between membrane-bound compartments. Most...
Eukaryotic cells are highly compartmentalized, requiring elaborate transport mechanisms to facilitate the movement of proteins between membrane-bound compartments. Most proteins synthesized in the endoplasmic reticulum (ER) are transported to the Golgi apparatus through COPII-mediated vesicular trafficking. Sar1, a small GTPase that facilitates the formation of COPII vesicles, plays a critical role in the early steps of this protein secretory pathway. Sar1 was characterized in yeast, animals and plants, but no Sar1 homolog has been identified and functionally analyzed in algae. Here we identified a putative Sar1 homolog (CrSar1) in the model green alga through amino acid sequence similarity. We employed site-directed mutagenesis to generate a dominant-negative mutant of CrSar1 (CrSar1DN). Using protein secretion assays, we demonstrate the inhibitory effect of CrSar1DN on protein secretion. However, different from previously studied organisms, ectopic expression of CrSar1DN did not result in collapse of the ER-Golgi interface in . Nonetheless, our data suggest a largely conserved role of CrSar1 in the ER-to-Golgi protein secretory pathway in green algae.
PubMed: 38887666
DOI: 10.1002/pld3.614 -
International Journal For Parasitology Jun 2024Oocysts of the protozoan Toxoplasma gondii are found in felid feces and can be washed into coastal waters, where they persist for months, attaching to algae and...
Detection of Toxoplasma gondii in wild bivalves from the Kerguelen and Galapagos archipelagos: influence of proximity to cat populations, exposure to marine currents and kelp density.
Oocysts of the protozoan Toxoplasma gondii are found in felid feces and can be washed into coastal waters, where they persist for months, attaching to algae and accumulating in invertebrates. We used wild bivalves to assess contamination of coastal waters of the Kerguelen and Galapagos archipelagos by this zoonotic parasite. Additionally, we leveraged the contrasting situations of these archipelagos to identify some potential drivers of contamination. In the Galapagos, with a cat density reaching 142 per km, 15.38% of the sampled oysters (Saccostrea palmula) tested positive for T. gondii by quantitative real-time PCR (qPCR) (n= 260), and positive samples were found in all eight sampling sites. In Kerguelen, with one to three cats per km, 40.83% of 120 tested mussels (Mytilus edulis platensis) were positive, and positive samples were found in four out of the five sampling sites. These findings provide evidence of T. gondii contamination in the coastal waters of these archipelagos. Furthermore, T. gondii-positive bivalves were found on islands located 20 km away (Galapagos) and 5 km away (Kerguelen) from the nearest cat population, indicating that T. gondii oocysts can disperse through waterborne mechanisms over several kilometers from their initial deposition site. In the Galapagos, where runoff is infrequent and all sites are exposed to currents, the prevalence of qPCR-positive bivalves did not show significant variations between sites (p= 0.107). In Kerguelen where runoff is frequent and site exposure variable, the prevalence varied significantly (p < 0.001). The detection of T. gondii in Kerguelen mussels was significantly correlated with the site exposure to currents (odds ration (OR) 60.2, p < 0.001) and the on-site density of giant kelp forests (OR 2.624, p < 0.001). This suggests that bivalves can be contaminated not only by oocysts transported by currents but also by consuming marine aggregates containing oocysts that tend to form in kelp forests.
PubMed: 38885873
DOI: 10.1016/j.ijpara.2024.06.001