Search Results (45)

Advanced methodologies for Botryllus schlosseri artificial seawater systems are needed to decrease dependency of large-scale culture on natural seawater and expand this important new model organism to more inland laboratories. We constructed two botryllid tunicate customized closed aquaculture systems, a static system consisting of aerated jars fed commercial filter feeder diet, and a recirculating aquaculture system (RAS) consisting of pertinent marine RAS components fed live microalgae and zooplankton diets. Initially, static tunicate culture yielded exponential growth in contrast to poor survival and negligible growth observed in RAS tunicates. RAS modifications were made to increase water treatment proficiency, which improved tunicate survival and growth. Experiments were performed isolating feed and water type as variables differentiating static and RAS and evaluating their specific effects. Live feed promoted five-fold greater growth relative to a commercial concentrate diet. Tunicates maintained in optimized RAS water achieved two-fold faster growth relative to animals in freshly prepared artificial seawater. Subsequent procedural modifications combined with the RAS revisions resulted in growth rates comparable to the static system. Both optimized systems are suitable for long-term husbandry of botryllid tunicate populations supporting both sexual and asexual modes of reproduction, with a current RAS residence time of over 24 months. Full article

Marine algae are emerging as important biological resources for the discovery and development of bioactive compounds with applications across food, pharmaceutical, cosmetic, agricultural, aquaculture, environmental, and biotechnological systems. This review critically synthesizes current knowledge on macroalgae and microalgae as sources of sulfated polysaccharides, carotenoids, phenolic compounds, proteins, peptides, vitamins, mycosporine-like amino acids, and polyunsaturated fatty acids. Emphasis is placed on the relationship between algal source, cultivation conditions, compound structure, extraction strategy, formulation, and biological activity. Key mechanisms of action are discussed, including antioxidant defense, modulation of inflammatory signaling, inhibition of metabolic enzymes, antimicrobial and antiviral activity, interactions with the gut microbiota, and regulation of cell-cycle-related pathways. Recent progress in biotechnological production, green extraction, purification, analytical characterization, bioaccessibility, bioavailability, and delivery systems is evaluated in the context of real product development. The review further highlights the use of algal bioactives in functional foods, nutraceuticals, pharmaceuticals, cosmeceuticals, aquafeeds, crop biostimulants, and environmental remediation. Current limitations, including biomass variability, compound instability, limited human validation, regulatory complexity, safety concerns, and scale-up costs, are also addressed. Overall, marine algae provide a sustainable and multifunctional platform for developing bioactive products when discovery, processing, validation, and commercialization are integrated. Full article

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are essential omega-3 polyunsaturated fatty acids (n-3 PUFAs) with well-established health benefits. They occur primarily in marine resources, while their quantitative distribution within the glycerolipidome is rarely analyzed. Therefore, we investigated major commercial sources, including 12 microalgal species, the protist Schizochytrium sp., four fish species, and nine commercial n-3 supplements (fish, krill and Schizochytrium-derived “algal” oils) by high-performance thin-layer chromatography–gas chromatography–mass spectrometry (HPTLC–GC–MS). The class-resolved mapping of EPA and DHA revealed signature lipid profiles across all sources. In microalgae, 60–80% of EPA was localized in glycolipids, whereas in Schizochytrium and fish, >90% of DHA occurred in triacylglycerols. Krill oils exhibited phospholipid-rich profiles with ~70% of phosphatidylcholine-bound DHA. Nutritional indices also highlighted major differences: fish and fish oils showed favorable PUFA-to-saturated FA ratios (>0.45) and hypocholesterolemic-to-hypercholesterolemic ratios (>1), while Schizochytrium-based “algal” oils even surpassed these values. The microalgae Nannochloropsis granulata contained the highest EPA content in biomass form, combined with favorable nutritional indices. Beyond total n-3 content in relation to recommended daily intake values, the lipid-class distribution and nutritional indices should be considered decisive metrics for evaluating the health relevance of n-3 resources in the human diet. Full article

The growing demand for sustainable, functional ingredients in the food industry has driven interest in marine-derived biopolymers. Among marine sources, microalgae represent a promising yet underexplored reservoir of bioactive gel-forming compounds, particularly extracellular polysaccharides (EPSs), both sulfated and non-sulfated, as well as proteins that exhibit unique gelling, emulsifying, and stabilizing properties. This study focuses on microalgal species with demonstrated potential to produce viscoelastic, shear-thinning gels, making them suitable for applications in food stabilization, texture modification, and nutraceutical delivery. Recent advances in biotechnology and cultivation methods have improved access to high-value strains, which exhibit promising physicochemical properties for the development of novel food textures, structured formulations, and sustainable food packaging materials. Furthermore, these microalgae-derived gels offer additional health benefits, such as antioxidant and prebiotic activities, aligning with current trends toward functional foods containing prebiotic materials. Key challenges in large-scale production, including low EPS productivity, high processing costs, and lack of regulatory frameworks, are critically discussed. Despite these barriers, advances in cultivation technologies and biorefinery approaches offer new avenues for commercial application. Overall, microalgal gels hold significant promise as sustainable, multifunctional ingredients for clean-label food formulations. Full article

The growing need for sustainable protein sources in aquaculture has led to interest in microalgae, such as Chlorella vulgaris, known for its high nutritional value. One promising strategy for delivering these nutrients is through bioencapsulation in Daphnia magna, a common live feed used in aquaculture. This study evaluated the effect of including D. magna bioencapsulated with C. vulgaris as live feed for marine shrimp Penaeus vannamei post-larvae. Shrimp were fed at two D. magna densities (5 and 10 per shrimp, 5DF and 10DF), offered weekly, and compared with a control group receiving only commercial feed (F) for 36 days in a synbiotic nursery system. Water quality, zootechnical performance, protein, and lipid content of the shrimp were analyzed using correlation analyses, nonlinear prediction models, and principal component analysis (PCA). Shrimp fed with the 10DF treatment exhibited superior zootechnical performance, characterized by a lower feed conversion ratio (1.01) and higher feed efficiency (99.97%), protein (70.91%), and lipid (32.45%) content in comparison with the 5DF and control. Quadratic regression predictive models indicated the possibility of further testing higher concentrations of D. magna per shrimp. The results indicates that the use of C. vulgaris bioencapsulated in D. magna as live feed for P. vannamei is a promising approach to improve shrimp diets and increase production in aquaculture. Full article

Polysaccharides (PSs) are the most abundant carbohydrates in nature, performing essential biological functions such as immune system regulation, structural support, and cell communication. PSs from marine microalgae have gained increasing attention due to their diverse biological activities and potential applications in various fields, including the human health sector. These natural macromolecules, primarily composed of glucose, xylose, galactose, rhamnose, and fucose, exhibit bioactive properties influenced by their molecular weight, sulfation degree, and structural complexity. Microalgal PSs can function as antiviral, antimicrobial, antioxidant, immunomodulatory, and antitumor agents, making them promising candidates for pharmaceutical and nutraceutical applications. Additionally, their physicochemical properties make them valuable as bioactive ingredients in cosmetics, serving as hydrating agents, UV protectants, and anti-ageing compounds. The production of PSs from microalgae presents a sustainable alternative to terrestrial plants, as microalgae can be cultivated under controlled conditions, ensuring high yield and purity while minimizing environmental impact. Despite their potential, challenges remain in optimizing extraction techniques, enhancing structural characterization, and scaling up production for commercial applications. This review provides an overview of the principal biological activities of PSs from eukaryotic microalgae and their possible use as ingredients for cosmetic applications. Challenges to address to implement their use as products to improve human health and wellbeing are also discussed. Full article

With the increasing use of manufactured nanomaterials in consumer products, especially silver nanoparticles (AgNPs), concerns about their environmental impact are rising. Two AgNP formulations were tested, the commercial nanosilver product nanArgen™ and a newly eco-designed bifunctionalized nanosilver (AgNPcitLcys), using marine organisms across three trophic levels, microalgae, microcrustaceans, and bivalves. Acute toxicity was assessed on the diatom Phaeodactylum tricornutum, brine shrimp larvae Artemia franciscana, and bivalve Mytilus galloprovincialis. The behavior of the formulations in marine media, including stability across a concentration range (0.001–100 mg/L), was also evaluated. Results showed that nanArgen™ was less stable compared to AgNpcitLcys, releasing more silver ions and exhibiting higher toxicity to microalgae (100% growth inhibition at 1 mg/L) and microcrustaceans (>80% mortality at 10 mg/L). Conversely, AgNPcitLcys (10 µg/L) was more toxic to bivalves, possibly due to the smaller nanoparticle size affecting lysosomal membrane stability. This study highlights how eco-design, such as surface coating, influences AgNP behavior and toxicity. These findings emphasize the importance of eco-design in minimizing environmental impacts and guiding the development of safer, more sustainable nanomaterials. Full article

Docosahexaenoic acid (DHA, C22:6n-3) is an omega-3 fatty acid with beneficial effects for human health. In view of its increasing demand, DHA traditionally produced by marine fisheries will be insufficient, and an alternative sustainable source is urgently required. Here, we report the isolation and characterization of four novel microalgae strains, PLU-A, B, C and D, with a high DHA content of up to 45% from decayed mangrove samples collected from a coastal area in Singapore. Phylogenetic analysis revealed that these isolates were clustered with Schizochytrium sp. TK6 (OK244290.1) and were identified as Schizochytrium sp. strains. A medium optimization with Schizochytrium sp. PLU-D found a glucose-to-yeast extract ratio of 4:1 to be optimal for high biomass and lipid accumulation of up to 70% in shake flasks. In fed-batch fermentation scale-up with the Schizochytrium sp. PLU-D strain, this translates to 175 g/L dry biomass, 94 g/L lipid and 36.2 g/L DHA. Accordingly, the DHA titer obtained is superior to most of the scale-up production reported thus far, while the DHA content is comparable to two other commercially available DHA algae oils. These results suggest that Schizochytrium sp. PLU-D has high potential to be applied for the sustainable production of DHA. Full article

Non-communicable diseases (NCDs) represent a global health challenge, constituting a major cause of mortality and disease burden in the 21st century. Addressing the prevention and management of NCDs is crucial for improving global public health, emphasizing the need for comprehensive strategies, early interventions, and innovative therapeutic approaches to mitigate their far-reaching consequences. Marine organisms, mainly algae, produce diverse marine natural products with significant therapeutic potential. Harnessing the largely untapped potential of algae could revolutionize drug development and contribute to combating NCDs, marking a crucial step toward natural and targeted therapeutic approaches. This review examines bioactive extracts, compounds, and commercial products derived from macro- and microalgae, exploring their protective properties against oxidative stress, inflammation, cardiovascular, gastrointestinal, metabolic diseases, and cancer across in vitro, cell-based, in vivo, and clinical studies. Most research focuses on macroalgae, demonstrating antioxidant, anti-inflammatory, cardioprotective, gut health modulation, metabolic health promotion, and anti-cancer effects. Microalgae products also exhibit anti-inflammatory, cardioprotective, and anti-cancer properties. Although studies mainly investigated extracts and fractions, isolated compounds from algae have also been explored. Notably, polysaccharides, phlorotannins, carotenoids, and terpenes emerge as prominent compounds, collectively representing 42.4% of the investigated compounds. Full article

Carotenoids are pigments that have a range of functions in human health. The carotenoid diatoxanthin is suggested to have antioxidant, anti-inflammatory and chemo-preventive properties. Diatoxanthin is only produced by a few groups of microalgae, where it functions in photoprotection. Its large-scale production in microalgae is currently not feasible. In fact, rapid conversion into the inactive pigment diadinoxanthin is triggered when cells are removed from a high-intensity light source, which is the case during large-scale harvesting of microalgae biomass. Zeaxanthin epoxidase (ZEP) 2 and/or ZEP3 have been suggested to be responsible for the back-conversion of high-light accumulated diatoxanthin to diadinoxanthin in low-light in diatoms. Using CRISPR/Cas9 gene editing technology, we knocked out the ZEP2 and ZEP3 genes in the marine diatom Phaeodactylum tricornutum to investigate their role in the diadinoxanthin–diatoxanthin cycle and determine if one of the mutant strains could function as a diatoxanthin production line. Light-shift experiments proved that ZEP3 encodes the enzyme converting diatoxanthin to diadinoxanthin in low light. Loss of ZEP3 caused the high-light-accumulated diatoxanthin to be stable for several hours after the cultures had been returned to low light, suggesting that zep3 mutant strains could be suitable as commercial production lines of diatoxanthin. Full article

Plastic pollution is a distinctive element of the globalized world. In fact, since the 1970s the expansion and use of plastics, particularly in the consumer and commercial sectors, has given this material a permanent place in our lives. The increasing use of plastic products and the wrong management of end-of-life plastic products have contributed to increasing environmental pollution, with negative impacts on our ecosystems and the ecological functions of natural habitats. Nowadays, plastic pollution is pervasive in all environmental compartments. As aquatic environments are the dumping points for poorly managed plastics, biofouling and biodegradation have been proposed as promising approaches for plastic bioremediation. Known for the high stability of plastics in the marine environment, this represents a very important issue to preserve marine biodiversity. In this review, we have summarized the main cases reported in the literature on the degradation of plastics by bacteria, fungi, and microalgae and the degradation mechanisms involved, to highlight the potential of bioremediation approaches to reduce macro and microplastic pollution. Full article

A range of volatile organic compounds (VOCs) have been found to be released during zooplankton grazing on microalgae cultivated for commercial purposes. However, production of grazing-derived VOCs from environmentally relevant species and their potential contribution to oceanic emissions to the atmosphere remains largely unexplored. Here, we aimed to qualitatively explore the suite of VOCs produced due to grazing using laboratory cultures of the marine microalga Isochrysis galbana and the herbivorous heterotrophic dinoflagellate Oxyrrhis marina with and without antibiotic treatment. The VOCs were measured using a Vocus proton-transfer-reaction time-of-flight mass spectrometer, coupled to a segmented flow coil equilibrator. We found alternative increases of dimethyl sulfide by up to 0.2 nmol dm⁻³ and methanethiol by up to 10 pmol dm⁻³ depending on the presence or absence of bacteria regulated by antibiotic treatment. Additionally, toluene and xylene increased by about 30 pmol dm⁻³ and 10 pmol dm⁻³, respectively during grazing only, supporting a biological source for these compounds. Overall, our results highlight that VOCs beyond dimethyl sulfide are released due to grazing, and prompt further quantification of this source in budgets and process-based understanding of VOC cycling in the surface ocean. Full article

Marine microalgae are considered an important feedstock of multiple valuable metabolic compounds of high biotechnological potential. In this work, the marine microalga Tetraselmis striata was cultivated in different scaled photobioreactors (PBRs). Initially, experiments were performed using two different growth substrates (a modified F/2 and the commercial fertilizer Nutri-Leaf (30% TN—10% P—10% K)) to identify the most efficient and low-cost growth medium. These experiments took place in 4 L glass aquariums at the laboratory scale and in a 9 L vertical tubular pilot column. Enhanced biomass productivities (up to 83.2 mg L⁻¹ d⁻¹) and improved biomass composition (up to 41.8% d.w. proteins, 18.7% d.w. carbohydrates, 25.7% d.w. lipids and 4.2% d.w. total chlorophylls) were found when the fertilizer was used. Pilot-scale experiments were then performed using Nutri-Leaf as a growth medium in different PBRs: (a) a paddle wheel, open, raceway pond of 40 L, and (b) a disposable polyethylene (plastic) bag of 280 L working volume. Biomass growth and composition were also monitored at the pilot scale, showing that high-quality biomass can be produced, with important lipids (up to 27.6% d.w.), protein (up to 45.3% d.w.), carbohydrate (up to 15.5% d.w.) and pigment contents (up to 4.2% d.w. total chlorophylls), and high percentages of eicosapentaenoic acid (EPA). The research revealed that the strain successfully escalated in larger volumes and the biochemical composition of its biomass presents high commercial interest and could potentially be used as a feed ingredient. Full article

Microalgae are microscopic photosynthetic organisms frequently found in fresh and marine water ecosystems. Various microalgal species have been considered a reservoir of diverse health-value products, including vitamins, proteins, lipids, and polysaccharides, and are broadly utilized as food and for the treatment of human ailments such as cancer, cardiovascular diseases, allergies, and immunodeficiency. Microalgae-derived carotenoids are the type of accessory pigment that possess light-absorbing potential and play a significant role in metabolic functions. To date, nearly a thousand carotenoids have been reported, but a very less number of microalgae have been used for the commercial production of carotenoids. This review article briefly discussed the carotenoids of microalgal origin and their therapeutic application. In addition, we have briefly compiled the optimization of culture parameters used to enhance microalgal carotenoid production. In addition, the latest biotechnological approaches used to improve the yields of carotenoid has also been discussed. Full article

The 1,2,3-triazole ring has been gaining increased attention in medicinal chemistry over the past few years since it has been associated with metabolic stability and several biological activities, including antifouling. Therefore, the hybridization of this heterocycle with other pharmacophores which showed ability to prevent marine biofouling can be a strategy to obtain more effective and stable compounds. Marine biofouling remains a huge challenge for maritime industries and public health, causing economic, human, and ecological concerns, with few environmentally safe options to prevent this phenomenon. Considering that the incorporation of an acetophenone into coatings was found to decrease the attachment of marine micro- and macro-organisms, and in an attempt to obtain new effective acetophenone derivatives, a series of triazolyl acetophenones were obtained, through hybridization with the 1,2,3-triazole ring and other pharmacophores, using the copper(I)-catalyzed alkyne–azide cycloaddition (CuAAC) methodology. Fourteen new acetophenone-1,2,3-triazole hybrids were obtained and screening against the settlement of the macrofouling mussel Mytilus galloprovincialis and on five biofilm-forming marine bacteria allowed identifying promising compounds. Three compounds were able to inhibit the growth of marine bacteria Roseobacter litoralis, while the other three compounds significantly inhibited the settlement of mussel larvae. For those, the ability to inhibit the growth of Navicula sp. microalgae was also evaluated. One acetophenone was found to display complementary antifouling activity against macrofouling mussel and microalgae Navicula sp. The most potent compounds also were shown to be less toxic to the non-target species Artemia salina than the commercial biocide Econea^®. Full article