Search Results (148)

Phycocyanin is a natural, non-toxic, blue pigment-protein with many commercial applications. Its exploitation in various biotechnological sectors strongly depends on its purity grade (P). Phycocyanin is largely used in food industry where a low purity grade is required, while its widespread use in sectors requiring a higher purity is hampered by the cost of large-scale industrial production. Industry, in fact, needs simple, easily scalable and cost-effective procedures to ensure sustainable production of high-quality pigment. In this work we applied the innovative two-step ultrasound-based process UltraBlu to the pilot-scale production of phycocyanin. A total of 50 L of biomass suspension of commercial Spirulina were processed in batch mode. The pigment extract was obtained in one day, including the biomass harvesting. Food/cosmetic grade (P = 1.41–1.76) and a good yield (Y = 59.2–76.1%) were achieved. The initial results obtained suggest that UltraBlu can be an effective scalable process suitable to produce phycocyanin also on an industrial scale. Full article

Alzheimer’s disease (AD) is characterized by β-amyloid plaques, neurofibrillary tangles, neuroinflammation, and oxidative stress—pathological features that pose significant challenges for the development of therapeutic interventions. Given these challenges, this review comprehensively evaluates the neuroprotective mechanisms of bioactive compounds derived from red algae, including polysaccharides and phycobiliproteins, which are considered a promising source of natural therapeutics for AD. Red algal constituents exhibit neuroprotective activities through multiple mechanisms. Sulfated polysaccharides (e.g., carrageenan, porphyran) suppress NF-κB-mediated neuroinflammation, modulate mitochondrial function, and enhance brain-derived neurotrophic factor (BDNF) expression. Phycobiliproteins (phycoerythrin, phycocyanin) and peptides derived from their degradation scavenge reactive oxygen species (ROS) and activate antioxidant pathways (e.g., Nrf2/HO-1), thus mitigating oxidative damage. Carotenoids (lutein, zeaxanthin) improve cognitive function through the inhibition of acetylcholinesterase and pro-inflammatory cytokines (TNF-α, IL-1β), while phenolic compounds (bromophenols, diphlorethol) provide protection by targeting multiple pathways involved in dopaminergic system modulation and Nrf2 pathway activation. Emerging extraction technologies—including microwave- and enzyme-assisted methods—have been shown to optimize the yield and maintain the bioactivity of these compounds. However, the precise identification of molecular targets and the standardization of extraction techniques remain critical research priorities. Overall, red algae-derived compounds hold significant potential for multi-mechanism AD interventions, providing novel insights for the development of therapeutic strategies with low toxicity. Full article

With the advancement of human industrial activities, increased carbon dioxide emissions have made global warming an inescapable trend. Elevated temperatures exert profound effects on the viability of large macroalgae. Bangia fuscopurpurea (Rhodophyta) is a commercially important large red alga widely cultivated along the coastal waters of Putian, Fujian Province, China; however, its physiological, biochemical, and molecular responses to heat stress remain unclear. To address this question, we cultured B. fuscopurpurea at 15 °C (control) and 28 °C (heat stress) for 7 days, assessed changes in growth and photosynthetic parameters, and performed transcriptome sequencing. Growth analysis revealed that the relative growth rate of B. fuscopurpurea at 28 °C was significantly lower than that at 15 °C. After 1 day at 28 °C, the chlorophyll a and carotenoid contents increased significantly; the phycobiliprotein levels rose markedly on days 4 and 7, whereas the Fv/Fm ratio decreased significantly on days 1, 4, and 7. Transcriptomic analysis indicated that heat stress up-regulated the majority of differentially expressed genes (DEGs) in B. fuscopurpurea. KEGG pathway enrichment analysis revealed that the DEGs were predominantly associated with photosynthesis, carbohydrate and energy metabolism, glycerophospholipid metabolism, and the glutathione cycle. In summary, B. fuscopurpurea mitigates the adverse effects of heat stress by up-regulating genes involved in photosynthesis, antioxidant defenses, and glycerophospholipid metabolism. These findings enhance our understanding of the physiological adaptations and molecular mechanisms by which B. fuscopurpurea responds to heat stress. Full article

Microalgae are increasingly recognised as sustainable, nutrient-dense sources of bioactive compounds with broad health-promoting potential. Rich in carotenoids, phenolics, polyunsaturated fatty acids, phycobiliproteins, sterols, and essential vitamins, microalgae offer a promising foundation for functional foods targeting chronic disease prevention. This narrative review explores the nutritional profiles and biological effects of key species, including Spirulina (Limnospira platensis), Chlorella, Haematococcus, and Nannochloropsis. Scientific evidence supports their antioxidant, anti-inflammatory, immunomodulatory, antimicrobial, and metabolic regulatory activities, contributing to reduced risks of cardiovascular, metabolic, inflammatory, and neurodegenerative disorders. Special emphasis is placed on the synergistic benefits of consuming whole biomass compared to isolated compounds and the technological strategies, such as encapsulation, cell wall disruption, and nutrient optimisation, that enhance the bioavailability of microalgal bioactives. Furthermore, the environmental advantages of microalgae cultivation, such as minimal land and freshwater requirements, carbon sequestration, and wastewater bioremediation, highlight their role in the transition toward sustainable food systems. Despite challenges related to high production costs, sensory attributes, scalability, and regulatory approval, advances in biotechnology, processing, and formulation are paving the way for their broader application. Overall, microalgae represent next-generation bioactive sources that promote human health and environmental sustainability, positioning them as key players in future functional foods and nutraceuticals. Full article

Allelochemicals are recognized as promising algaecides due to their environmental safety. Para-tert-butylcatechol (TBC) and L-lysine exhibit significant potential in suppressing harmful algal blooms (HABs); however, their combined effects and algae inhibition mechanisms remain unelucidated. Therefore, this study systematically investigated the growth inhibition of Microcystis aeruginosa by TBC and L-lysine individually and in combination, while simultaneously examining their combined effects on algal growth, cell membrane integrity, photosynthetic activity, antioxidant responses, and microcystin production. The results revealed a significant interactive effect between TBC (0.04 mg/L) and L-lysine (1 mg/L), achieving over 90% growth inhibition within 96 h. The combined treatment significantly inhibited M. aeruginosa growth through impaired photosynthetic efficiency and elevated oxidative stress. Compared to the control group, the treatment group exhibited a continuous decline in chlorophyll-a content, phycobiliprotein levels, F_v/F_m, YII, α, and rETR_max, while phosphoenolpyruvate carboxylase (PEPC) activity decreased by 96.48% by day 8. And antioxidant enzymes, including superoxide dismutase (SOD) and reduced glutathione (GSH), showed a progressive increase in activity. In addition, the structure and integrity of the cell membrane of M. aeruginosa were damaged after treatment, and the conductivity of the treatment groups increased continuously from 2.32 to 4.63 μs/cm. In addition, under combined treatment, intra- and extracellular microcystin levels initially increased (peaking at day 2) but sharply declined thereafter, becoming significantly lower than controls by day 8. These findings highlight the potential of combining TBC and L-lysine as an eco-friendly and cost-effective strategy for mitigating M. aeruginosa-dominated harmful algal blooms. Full article

Limnospira spp., commercially known as spirulina, is widely recognized for its remarkable benefits due to its rich composition of bioactive compounds like phycobiliproteins, carotenoids, and phenolic compounds. These natural bioactive compounds not only serve as colorants but also offer potent antioxidant, anti-inflammatory, immunomodulatory, anticancer, antimicrobial, and anti-aging properties. As a result, spirulina and its components are increasingly used in cosmetic formulations to promote skin hydration, reduce wrinkles, and protect against UV radiation damage. Its bioactive components enhance fibroblast growth, boost collagen production, and prevent premature skin aging by inhibiting enzymes responsible for elastin degradation. Additionally, spirulina-based cosmetics have demonstrated wound-healing properties without genotoxic effects, with formulations containing C-phycocyanin particularly effective in shielding skin cells from UV-induced apoptosis. Despite these well-established benefits, there remains significant potential for the cosmetic industry to harness spirulina’s capabilities further. Research into the molecular mechanisms underlying its bioactive compounds in cosmetic formulations is still in its early stages, offering many opportunities for innovation. Emerging fields of biotechnology, such as nanotechnology and biocosmetics, could enhance the stability, efficacy, and delivery of spirulina-based ingredients, unlocking new possibilities for skin protection and rejuvenation. Furthermore, its proven biological properties align perfectly with the increasing consumer demand for safe, sustainable, and nature-inspired skincare solutions. Full article

Marine microalgae have emerged as promising biofactories for the sustainable production of high-value bioactive compounds with significant applications in human health, cosmetics, and functional foods. This review offers a comprehensive overview of the primary classes of bioactives synthesised by marine microalgae, including polyunsaturated fatty acids, carotenoids, phycobiliproteins, peptides, sterols, polysaccharides, phenolic compounds, vitamins, mycosporine-like amino acids, and alkaloids. These compounds demonstrate diverse biological activities, such as antioxidant, anti-inflammatory, antimicrobial, anticancer, immunomodulatory, and photoprotective effects, increasingly validated through in vitro, and clinical studies. Their mechanisms of action and roles in disease prevention and wellness promotion are examined in detail, with an emphasis on pharmaceutical (e.g., cardiovascular, neuroprotective), cosmetic (e.g., anti-ageing, UV protection), and nutraceutical (e.g., metabolic and immune-enhancing) applications. The review also addresses critical challenges in strain selection, cultivation technologies, downstream processing, product standardisation, and regulatory approval. Simultaneously, emerging opportunities driven by synthetic biology, omics integration, and circular biorefinery approaches are transforming marine microalgae into precise platforms for next-generation bioproducts. By summarising current knowledge and future directions, this work underscores the essential role of marine microalgae in advancing the blue bioeconomy and tackling global sustainability challenges. Full article

The red seaweed Asparagopsis taxiformis (Bonnemaisoniaceae, Rhodophyta) produces a bioactive natural product, bromoform, which, when fed to ruminant livestock, can eradicate methane emissions. However, to cultivate enough A. taxiformis to produce a yield that would have a meaningful impact on global greenhouse gas emissions, we need to advance our current understanding of the biology of this seaweed species. Here, we used both a domesticated diploid tetrasporophyte (>1.5 years in culture) and wild samples to establish a high-quality draft nuclear genome for A. taxiformis (lineage 6 based upon phylogenetic analyses using the cox2-3 spacer). The constructed nuclear genome is 142 Mb in size (including 70.67% repeat regions) and was determined to encode for approximately 10,474 protein-coding genes, including those associated with secondary metabolism, photosynthesis, and defence. To obtain information regarding molecular differences between cultured and wild tetrasporophytes, we further explored differential gene expression relating to their different growth environments. Cultured tetrasporophytes, which contained a relatively higher level of bromoform compared to wild tetrasporophytes, demonstrated an enrichment of regulatory factors, such as protein kinases and transcription factors, whereas wild tetrasporophytes were enriched for the expression of defence and stress-related genes. Wild tetrasporophytes also expressed a relatively high level of novel secretory genes encoding proteins with von Willebrand factor A protein domains (named rhodophyte VWAs). Gene expression was further confirmed by proteomic investigation of cultured tetrasporophytes, resulting in the identification of over 400 proteins, including rhodophyte VWAs, and numerous enzymes and phycobiliproteins, which will facilitate future functional characterisation of this species. In summary, as the most comprehensive genomic resource for any Asparagopsis species, this resource for lineage 6 provides a novel avenue for seaweed researchers to interrogate genomic information, which will greatly assist in expediating production of Asparagopsis to meet demand by both aquaculture and agriculture, and to do so with economic and environmental sustainability. Full article

Phycobiliproteins (PBPs), captivating water-soluble proteins found in cyanobacteria, red algae, and cryptophytes, continue to fascinate researchers and industries due to their unique properties and multifaceted applications. These proteins consist of chromophores called phycobilins (PBs), covalently linked to specific protein subunits. Major phycobiliproteins include phycocyanin (PC), allophycocyanin (APC), and phycoerythrin (PE), each distinguished by distinct absorption and emission spectra. Beyond their colorful properties, PBs exhibit a broad spectrum of biological activities, including antibacterial, antifungal, antiviral, and antidiabetic effects, making them valuable for pharmaceutical, biotechnological, and medical purposes. The extraction and purification methods for PBs have been optimized to enhance their bioavailability and stability, opening new avenues for industrial production. For this review, a comprehensive literature search was conducted using scientific databases such as PubMed, Scopus, and Web of Science, prioritizing peer-reviewed articles published between 2000 and 2025, with an emphasis on recent advances from the last five years, using keywords such as “phycobiliproteins”, “phycobilins”, “bioactivities”, “therapeutic applications”, and “industrial use”. Studies were selected based on their relevance to the biological, technological, and pharmacological applications of PBPs and PBs. This review explores the diverse applications of PBs in therapeutic, diagnostic, and environmental fields, highlighting their potential as natural alternatives in the treatment of various diseases. The future perspectives for PBs focus on their incorporation into innovative drug delivery systems, biocompatible materials, and functional foods, presenting exciting opportunities for advancing human health and well-being. Full article

Nostoc sphaeroides is a cyanobacterium known for its valuable health benefits, including antioxidant, anti-inflammatory, and immune-boosting properties, making it a promising addition to functional foods. However, large-scale cultivation has remained necessary due to economic value and decreased yield. This study focused on the effect of varying inoculation densities and seasonal conditions on the growth and quality of N. sphaeroides. The main results were as follows: The highest average fresh weight productivity per unit volume was observed in summer and autumn at an inoculation density of 10 g·L⁻¹, with values of 0.26 g·L⁻¹·d⁻¹ and 0.31 g·L⁻¹·d⁻¹, respectively. In winter and spring, the highest productivity was achieved at an inoculation density of 15 g·L⁻¹, with values of 0.52 g·L⁻¹·d⁻¹ and 1.40 g·L⁻¹·d⁻¹, respectively. Nutritional components varied seasonally, with chlorophyll and carotenoid contents peaking in spring and phycobiliproteins, including phycocyanin, allophycocyanin, and phycoerythrin, reaching their highest levels in summer. The dry weight was greatest in summer, while the total protein content was highest in autumn, with values of 40.87%, 39.66%, and 41.44% for 5 g·L⁻¹, 10 g·L⁻¹, and 15 g·L⁻¹, respectively. In terms of texture, the hardness of N. sphaeroides was highest in autumn at inoculation densities of 5 g·L⁻¹ and 15 g·L⁻¹, with values of 153.96 g and 146.88 g, respectively. At 10 g·L⁻¹, the highest hardness was observed in spring (109.67 g). The elasticity and chewiness of the algae were best in spring across all inoculation densities, with elasticity values of 2.86, 2.54, and 2.07, and chewiness values of 112.37, 120.67, and 75.96 for 5 g·L⁻¹, 10 g·L⁻¹, and 15 g·L⁻¹, respectively. In conclusion, the optimal inoculation density for summer and autumn is 10 g·L⁻¹, while for winter and spring, it is 15 g·L⁻¹. N. sphaeroides exhibits better texture in spring. This study offers valuable information for the large-scale cultivation and functional food applications of N. sphaeroides. Full article

This study evaluates the chemical composition, fatty acid profiles, and bioactive properties of ethanolic (SPE), methanolic (SPM), and acetonic (SPA) extracts of Arthrospira platensis. The chemical analysis revealed a high protein content (72.08%), moderate lipid levels (6.49%), and a diverse fatty acid profile, dominated by polyunsaturated fatty acids. Antibacterial testing showed that SPE exhibited the strongest activity against Gram-negative bacteria, including Escherichia coli (ATCC 25922), Enterobacter cloacae (ATCC 49141), Proteus mirabilis (ATCC 25933), Salmonella typhi (ATCC 6539), Salmonella typhimurium (ATCC 14028), Salmonella enteritidis (ATCC 13076), Salmonella gallinarum (ATCC 9184), and Pseudomonas aeruginosa (ATCC 27853). The anticoccidial activity was also significant, with SPE reducing Eimeria sp. oocyst counts in poultry intestines and ceca. Antioxidant activity was highest in SPM, which also had the highest phenolic content. LC-MS/MS profiling of the methanolic extract revealed various bioactive compounds, including phenolic acids, flavonoids, carotenoids, chlorophylls, and phycobiliproteins. These results suggest that A. platensis has great potential as a nutraceutical supplement in poultry farming, offering a sustainable alternative to synthetic additives. Full article

Phycobiliproteins and pigments derived from cyanobacteria hold significant potential for diverse applications in the food, pharmaceutical, and chemical industries. The filamentous cyanobacterium Anabaena cylindrica serves as a valuable resource for extracting these compounds. This study develops a simplified, safe, and cost-effective extraction method that eliminates toxic solvents and minimizes processing steps. This makes the method applicable for all users and allows the easy integration of the extraction into biorefinery concepts in which the biomass is to be used as a fertilizer, for example. Utilizing salts such as ammonium sulfate and calcium chloride (15 gL⁻¹ each) enables the effective extraction of phycocyanin (PC) and allophycocyanin, achieving a PC concentration of 192.34 $\mathrm{mg}{\mathrm{g}}_{\mathrm{CDW}}^{-1}$ and 209.44 $\mathrm{mg}{\mathrm{g}}_{\mathrm{CDW}}^{-1}$, respectively. Ethanol was introduced as a less toxic alternative to methanol for pigment extraction, increasing chlorophyll a and carotenoid recovery by 21% and 37%, respectively. Full article

Porphyra specimens are red macroalgae with significant economic importance for food and pharmaceutical industries due to their physiological activities resulting from their bioactive compounds (BACs). Due to its economic importance, this research aimed to characterize the photosynthetic and biochemical aspects of the conchocelis and blade phases of Porphyra linearis to understand and help improve production of this algae. The algae were cultured for 7 days with nutrients for blade phase measurements, while another portion was cultured without nutrients for 21 days to release carpospores, which were cultivated for 4 months. For both phases, the content of BACs (chlorophyll a, carotenoids, phycobiliproteins, phenols, carbohydrates, proteins, mycosporine-like amino acids), antioxidant activity, and photosynthetic parameters were analyzed. Most of the parameters showed the blade phase had better results than conchocelis, except for carbohydrates. Phycobiliproteins showed no statistical differences between the phases. These findings highlight that conchocelis is not a good BACs source compared to the blade phase, but it is a crucial phase in the life cycle of Porphyra. Understanding the key parameters for maintaining the cultivation of conchocelis stocks for the development of the blade phase is a way to produce macroscopic biomass of this economically important algae throughout the year. Full article

Background/Objectives: In recent years the global incidence of cancer during pregnancy is rising, occurring in 1 out of every 1000 pregnancies. In this regard, the most used chemotherapy drugs to treat cancer are alkylating agents such as cyclophosphamide (Cp). Despite its great efficacy, has been associated with the production of oxidative stress and DNA damage, leading to embryotoxicity, genotoxicity, and teratogenicity in the developing conceptus. Therefore, this study aimed to investigate the protective role of phycobiliproteins (PBP) derived from Arthrospira maxima (spirulina) in reducing Cp-induced embryotoxicity and genotoxicity in pregnant CD1 mice. Methods: Pregnant CD1 mice were divided into five groups: control, Cp 20 mg/kg, and three doses of PBP (50, 100, and 200 mg/kg) + Cp co-treatment. PBP were administered orally from day 6 to 10.5 dpc, followed by a single intraperitoneal dose of Cp on 10.5 dpc. Embryos were collected at 12.5 dpc to assess morphological development and vascular alterations, while maternal DNA damage was evaluated using micronucleus assays and antioxidant enzyme activity in maternal plasma. Results: PBP exhibited a dose-dependent protective effect against Cp-induced damage. The 200 mg/kg PBP dose significantly reduced developmental abnormalities, micronucleated polychromatic erythrocytes, and oxidative stress, (as evidenced by increased SOD and GPx activity). Conclusions: Phycobiliproteins from Arthrospira maxima (spirulina) effectively reduced Cp-induced morphological and vascular alterations in embryos and genotoxicity in pregnant mice. These findings highlight their potential as a complementary therapy to mitigate teratogenic risks during chemotherapy. Further research is needed to optimize dosing and explore clinical applications. Full article

Arthospira platensis is a filamentous cyanobacterium considered an important source of phycobiliproteins (PBP), a class of water-soluble pigments with a wide range of applications. Although several extraction and purification techniques of PBP have been reported, there is still a need for strategies that achieve a balance between simplicity, cost-effectiveness, and scalability. To address this need, this study systematically evaluated conventional extraction methods—homogenisation, freeze–thaw cycles, and maceration. Maceration showed the best balance between yield purity and recovery among the tested techniques, and under optimal conditions (three cycles, 2 h/cycle, 0.1 M phosphate buffer), 55.9 mg/g of biomass of phycocyanin (PC) and 24.9 mg/g of biomass of allophycocyanin (APC) with notable antioxidant capacity (Folin-Ciocalteu’s and ABTS^●+ assays) were yielded. Among the tested purification techniques, ammonium sulphate fractionation achieved a purity of 2.3 with recoveries of 92.9% and 79.9% for PC and APC, respectively, while purification with 0.5% activated carbon resulted in an extract purity of 2.5 and recoveries of 90.9% (PC) and 87.2% (APC). The suggested procedures could be considered a fast and cost-effective way to obtain cosmetic-grade PBP, thus offering an accessible solution for industries prioritising sustainable and economically viable production pipelines. Full article