The functional state of enrichment cultures of the Eustigmatophycean strains Vischeria vischeri MZ–E3 and MZ–E4 after 25-day cultivation in the BBM medium was studied. The concentrations of ...chlorophyll a, total carotenoids, protein, vitamins A and E, fatty acid peroxidation product content, an antioxidant enzyme, and succinate dehydrogenase activity were measured. MZ–E3 succinate dehydrogenase activity was significantly higher by 2.21 times; the MZ–E4 strain had 2.94 times higher glutathione peroxidase activity. The MZ–E3 antioxidant activity index and the MZ–E3 unsaturation of fatty acids were 1.3 and 1.25 times higher than the MZ–E4. The retinol and α-tocopherol content of the MZ–E3 was 28.6% and 38.76% higher than MZ–E4. The main fatty acid profile differences were the 3.46-fold and 3.92-fold higher stearic and eicosapentaenoic acid content in the MZ–E4 biomass. MZ–E3 had higher antioxidant, energy, and metabolic and photosynthetic status than MZ–E4. The antioxidant status of the studied strains showed the dependence of the adaptive mechanisms of each, associated with differences in the ecological conditions of the biotopes from which they were isolated. These strains are promising for producing α-tocopherol and biomass enriched with omega-3 and omega-6 fatty acids.
In recent years, a growing concern has emerged regarding the environmental implications of flame retardants (FRs) like tetrabromobisphenol-A (TBBPA) and graphene family nanomaterials (GFNs), such as ...graphene, graphene oxide (GO), and reduced graphene oxide (rGO), on marine biota. Despite these substances' well-established individual toxicity profiles, there is a notable gap in understanding the physicochemical interactions within the binary mixtures and consequent changes in the toxicity potential. Therefore, our research focuses on elucidating the individual and combined toxicological impacts of TBBPA and GFNs on the marine alga Chlorella sp. Employing a suite of experimental methodologies, including Raman spectroscopy, contact angle measurements, electron microscopy, and chromatography, we examined the physicochemical interplay between the GFNs and TBBPA. The toxicity potentials of individual constituents and their binary combinations were assessed through growth inhibition assays, quantifying reactive oxygen species (ROS) generation and malondialdehyde (MDA) production, photosynthetic activity analyses, and various biochemical assays. The toxicity of TBBPA and graphene-based nanomaterials (GFNs) was examined individually and in combinations. Both pristine TBBPA and GFNs showed dose-dependent toxicity. While lower TBBPA concentrations exacerbated toxicity in binary mixtures, higher TBBPA levels reduced the toxic effects compared to pristine TBBPA treatments. The principal mechanism underlying toxicity was ROS generation, resulting in membrane damage and perturbation of photosynthetic parameters. Cluster heatmap and Pearson correlation were employed to assess correlations between the biological parameters. Finally, ecological risk assessment was undertaken to evaluate environmental impacts of the individual components and the mixture in the algae.
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•The toxicity of TBBPA towards algal cells was concentration-dependent.•TBBPA showed an increment in the oxidative stress generation in algal cells.•At lower concentrations of TBBPA, TBBPA + GFNs showed increase in toxic effects.•At higher concentrations of TBBPA, TBBPA + GFNs showed decrease in toxic effects.•The risk quotient of TBBPA towards the algae reduced in the presence of GFNs.
Livestock production systems are responsible for producing ~18% of the total anthropogenic greenhouse gas (GHG) emissions. Numerous alternatives, such as feed additives or supplements, have been ...proposed to meet these challenges. Marine algae have been proposed for gas reduction in ruminants; nevertheless, there are still very few experimental reports. Thus, the objective of the current study was to identify the volatile organic compounds (VOCs) in three marine algae—Kelp (Macrocystis pyrifera), Ulva (Ulva spp.), and Silk (Mazzaella spp.)—and to test their in vitro ruminal fermentation characteristics, gas profiles, and ability to mitigate biogas production. The evaluation of the VOCs in marine algae was performed using a flash gas chromatography electronic nose (FGC-E-Nose). The in vitro study was elaborated through in vitro incubation and gas production. The data obtained were analyzed using a completely randomized design. In total, forty-three volatile compounds were identified for Kelp algae, thirty-eight were identified for Ulva algae, and thirty-six were identified for Silk algae; the compounds were from different chemical families and included aromas, alcohols, aldehydes, phenolics, carboxylic acids, esters, and nutraceutical properties. Dry matter degradability was significantly (p < 0.05) affected by the algae type. The cumulative ruminal gas production was different (p < 0.05) between treatments. Kelp algae presented a major (V; p < 0.05) volume of gas produced compared to the other algae. Lag time (l; p < 0.05) was increased by Kelp alga; however, there were no differences (p>0.05) between the Silk and Ulva algae. The gas production rate was higher (s; p < 0.05) for Silk algae compared to the others. Ulva and Silk algae demonstrated a significant (p < 0.05) decrease in carbon dioxide emissions. Nevertheless, Kelp algae reduced the proportional methane (CHsub.4 ) production (p < 0.05) after 48 h of incubation, with the lowest emission rate of 47.73%. In conclusion, algae have numerous bio compounds that provide some properties for use in ruminant diets as additives to reduce methane and carbon dioxide emissions.
Chrypthecodinium cohnii lipids have been almost exclusively used as a source of Docosahexaenoic acid (DHA). Such an approach wastes the remaining microalgal lipid fraction. The present work presents ...a novel process to produce C. cohnii biomass, using low-cost industrial by-products (raw glycerol and corn steep liquor), in a 7L-bioreactor, under fed-batch regime. At the end of the fermentation, the biomass concentration reached 9.2 g/L and the lipid content and lipid average productivity attained 28.0% (w/w dry cell weight) and 13.6 mg/L h, respectively. Afterwards the microalgal biomass underwent a saponification reaction to produce fatty acid (FA) soaps, which were further converted into FA ethyl ester (FA EE). C. cohnii FA EE mixture was then fractionated, using the urea complexation method at different temperatures, in order to obtain a polyunsaturated fatty acid ethyl ester (PUFA EE) rich fraction, that could be used for food/pharmaceutical/cosmetic purposes, and a saturated fatty acid ethyl ester (SAT EE) rich fraction, which could be used as biodiesel. The temperature that promoted the best separation between PUFA and SAT EE, was −18 °C, resulting in a liquid fraction with 91.6% (w/w) DHA, and a solid phase with 88.2% of SAT and monounsaturated fatty acid ethyl ester (MONOUNSAT), which could be used for biodiesel purposes after a hydrogenation step.
Isochrysis galbana, a crucial primary producer and food source in aquatic ecosystems, faces increasing challenges from climate change and emerging contaminants like antibiotics. This study ...investigates the combined effects of sudden temperature increase (representing marine heatwaves) and rapid salinity change (representing extreme precipitation events) on the toxicity of tetracycline (TC) and oxytetracycline (OTC) to I. galbana. Short-term experiments reveal heightened antibiotic toxicity at 31 °C or salinities of 18 PSU, surpassing algal tolerance limits. Long-term tests show decreased inhibition of algal growth on day 9, indicating algal adaptation to the environment. Analyses of photosynthesis II efficiency, pigment content, and macromolecular composition support this, suggesting adaptation mechanism activation. While algae acclimate to the environment during long-term antibiotic exposure, extreme weather conditions may compromise this adaptation. These findings have implications for managing antibiotics in aquatic environments under climate change.
•First study to explore the impact of climate change and antibiotics on marine algae•First time to explore the effects of climate change events on antibiotic exposure•TC and OTC exhibited similar acute toxicity due to similar chemical structures.•Algal adaptation alleviates antibiotic toxicity during marine heat waves.
Cancer is a leading cause of death in both developing and developed countries. With the increase in the average global life expectancy, it has become a major health problem and burden for most public ...healthcare systems worldwide. Due to the fewer side effects of natural compounds than of chemotherapeutic drugs, increasing scientific attention is being focused on the development of anti-cancer drugs derived from natural sources. Marine algae are an interesting source of functional compounds with diverse health-promoting activities. Among these compounds, polysaccharides have attracted considerable interest for many years because of their excellent anti-cancer abilities. They improve the efficacy of conventional chemotherapeutic drugs with relatively low toxicity to normal human cells. However, there are few reviews summarising the unique anti-cancer effects and underlying mechanisms of marine algae polysaccharides (MAPs). Thus, the current review focuses on updating the advances in the discovery and evaluation of MAPs with anti-cancer properties and the elucidation of their mechanisms of action, including the signalling pathways involved. This review aims to provide a deeper understanding of the anti-cancer functions of the natural compounds derived from medicinal marine algae and thereby offer a new perspective on cancer prevention and therapy with high effectiveness and safety.
This is a book that has been divided into 9 chapters, including information on the recovery of highly valuable compounds for microalgae. The authors of this volume discuss seaweed as a renewable and ...globally available feedstock with potential applications in the food and feed industries, as well as the agricultural, chemical, or pharmaceutical fields. The chapters include discussions on a wide range of topics including an overview of seaweed by-products, Algae and microalgae biorefineries, the potential use of seaweed by-products in various products and materials, colour stability, and pigment contents of powdered laver (Pyropia yezoensis). The text also includes the interactions of the algae Sargassum muticum with metals as a starting point for the valorisation of invasive seaweed species, as well as new insights into the nutrition and functionality of seaweed. Microalgae biomass as an ingredient to design added value in food products, as well as seaweed biomass for bioremediation or Ethanol creation are additional topics.
