Search Results (309)

The growing demand for sustainable, non-animal-derived, and low-allergenic protein alternatives has driven research into innovative sources such as microalgae. This review focuses on three key microalgal species Arthrospira platensis (Spirulina), Chlorella vulgaris, and Tetraselmis chuii. It examines their cell wall structures, protein content, and amino acid profiles. Protein extraction methods, including physical, enzymatic, and chemical approaches, are critically discussed. Downstream purification techniques aimed at improving protein purity and quality are also reviewed. Protein characterization methods are discussed, highlighting their relevance to food applications. The potential applications of microalgal biomass and protein extracts in food and beverage products are evaluated, with consideration given to their functionality, safety, and regulatory aspects. Despite significant advances in this field, further research is essential to optimize extraction and processing technologies, facilitate their integration into mainstream food production, and improve overall process efficiency. Full article

Maintaining sustainable production of healthy and nutritious food represents a major global challenge. Cultivated meat could reduce the environmental impact of livestock production, but it remains costly, largely due to the expense of fetal bovine serum, a common cell culture media supplement. Algal and cyanobacterial proteins, particularly phycobiliproteins, represent promising sustainable sources of potentially bioactive peptides that may contribute to the development of serum-reduced or serum-free culture media. This study investigated the potential of hydrolysates prepared using the protein extracts of the red alga Porphyra haitanensis and the cyanobacterium Arthrospira platensis as functional supplements for cell cultivation in a low-serum environment. Twelve hydrolysates were generated by treating protein extracts from Arthrospira platensis and Porphyra haitanensis with six proteolytic enzymes: pepsin, trypsin, chymotrypsin, subtilisin, thermolysin and proteinase K. The effects of these hydrolysates were studied in three cell models of mammalian (CHO-K1), avian (QM7), and fish (MACK1) origin. The effects of hydrolysates on cell viability, proliferation, and antioxidant activity were evaluated. A. platensis–chymotrypsin hydrolysate significantly improved QM7 cell viability compared to control in both 80% reduced-serum and tryptose phosphate broth conditions (p ≤ 0.0001). Additionally, peptide composition analysis and identification of amino acid sequences provided preliminary insights into potentially bioactive chromopeptides associated with the maintenance and promotion of cellular growth. Algae/cyanobacteria-derived hydrolysates positively regulated cell viability and proliferation in serum-reduced conditions, although effects were dependent on the algal species, enzymatic treatment, and cell type. These findings highlight their potential as sustainable supplements for alternative cell culture media. Full article

The development of sustainable, nutrient-dense food systems requires a comprehensive understanding of how microalgae influence the mechanical properties of starch hydrogels. While certain microalgae are common food additives, a critical research gap remains regarding their effect on the rheological behavior and structural integrity of potato starch gels specifically. This study addressed this gap by evaluating the mechanical, microstructural and optical impacts of Arthrospira platensis (commonly known as Spirulina) and Chlorella vulgaris at 0.5%, 1% and 2% (w/w). Utilizing steady-shear flow tests, colorimetry, NIR spectroscopy and microscopy, we characterized changes in steady rheological parameters, color, chemical changes and microstructure of fortified hydrogels. Results indicated that filamentous Arthrospira platensis reinforces the matrix, significantly increasing yield stress from 10.2 Pa in the control to 32.4 Pa at 2% inclusion. In contrast, spherical Chlorella vulgaris appears to act as a structural filler, reducing yield stress to 4.8 Pa at 2%. Microscopy confirmed these morphological influences, showing Arthrospira platensis filaments entangling granules while Chlorella cells integrated into inter-granular spaces. Colorimetry revealed significant darkening (L* decreased from 31.59 to 18.54 at 2% Spirulina addition) and significant greening (p < 0.05). NIR spectroscopy demonstrated potential physical interactions via vibrational markers at 5172 cm⁻¹ and 5646 cm⁻¹, indicating water matrix redistribution within the system. This research demonstrates how incorporating Spirulina and Chlorella vulgaris provides a viable approach for modifying the physical properties of starch-based matrices. The findings indicate that Spirulina enhances flow resistance and structural stability under steady shear, whereas Chlorella vulgaris reduces flow barriers, thereby increasing the spreadability of these composite food systems. Full article

Fetal bovine serum (FBS) is commonly added to cell culture media, but for cultivated meat production to become truly sustainable, ethical and affordable, an alternative to it is necessary. The purpose of this study was to demonstrate how myoblasts could be cultivated in reduced-serum media using animal-free scaffolds. Novel chitosan/carrageenan hydrogels were developed and conjugated with peptides obtained by digestion of C-phycocyanin from cyanobacteria Arthrospira platensis, their physico-chemical properties were assessed, and their ability to serve as scaffolds for myoblast cultivation in reduced-serum media was examined. These hydrogels were found to possess suitable physical characteristics to serve as scaffolds for cell culture, and it was demonstrated that their use made quail muscle clone 7 (QM7) cell cultivation possible in reduced-FBS media. These hydrogels, therefore, are a promising candidate for use as scaffolds in future cultivated meat production studies. Full article

Microalgae represent a promising alternative as biofertilizers and biostimulants, providing essential nutrients and bioactive compounds that support plant growth. In this study, a screening of seven microalgal species—including Arthrospira platensis, Nannochloris sp., Chlorella sp., Chlorella vulgaris, Acutodesmus obliquus, Parachlorella kessleri, Coelastrella vacuolata—and one isolated mixed culture was conducted to evaluate their potential as biostimulants and biofertilizers under autotrophic cultivation conditions. Whole cultures and corresponding supernatants were directly applied, without any pretreatment, reducing potential processing costs. Their biostimulant activity was evaluated through multiple bioassays, including germination index and auxin- and cytokinin-like responses, while nitrogen, phosphorus, and potassium content was analyzed to assess biofertilizer potential. The results revealed that biostimulant effects were strongly influenced by species, concentration, and sample fraction. Chlorella species consistently showed high performance across assays, combining strong germination and rooting responses with high nitrogen content (8.2–8.8% w/w), while A. platensis and Nannochloris sp. showed inhibitory effects in many cases. Overall, under the cultivation and application conditions tested, C. vulgaris, mixed culture, and A. obliquus are identified as promising candidates for combined biostimulant and biofertilizer applications. This study is a primary step in identifying the most promising species as an alternative to synthetic fertilizers, enabling further optimization towards more sustainable agricultural practices. Full article

Sustainable CO₂ capture can be achieved using photosynthetic microorganisms such as Arthrospira platensis. This work investigates CO₂ capture and O₂ generation efficiency by employing multiple column-type bubbled photobioreactors with Arthrospira platensis pre-adapted long-term to enhanced CO₂ concentrations. Thirty photobioreactors (10 L each) were placed inside a sealed chamber (2 × 2 × 3 m). Three 12-day experiments under constant illumination (225 μmol/m²·s) and temperature (27 °C) and different CO₂ concentration were conducted at 1.5, 3.0, and 6.0 vol.%. During the experiments, the gas composition within chamber, biomass accumulation, and chemical composition of the culture medium (pH, concentrations of carbonates, bicarbonates, nitrates and phosphates) were monitored. With an increase in CO₂ concentration from 1.5 to 6%, the biomass growth rate increased from 321 to 344 mg/(L·day), while CO₂ capture and O₂ generation efficiency estimated from biomass accumulation changed from 432 to 480 mg/(L·day) and from 371 to 412 mg/(L·day), respectively. Increasing CO₂ concentration effectively suppressed medium alkalinization (pH maintained at 8.75–9.30 at 6.0% CO₂ vs. >9.8 at 1.5% CO₂) and sustained bicarbonate availability. Microscopic analysis confirmed high culture viability (>85% live trichomes) at all studied concentrations. The obtained results can be used for Arthrospira platensis-based CO₂-enhanced biofixation and accumulation of valuable biomass. Full article

Phycocyanin, a phycobiliprotein derived from the cyanobacterium Limnospira (Arthrospira) platensis (commonly known as Spirulina), is recognized for its antioxidant, immunomodulatory, and bioactive properties. This research aims to develop a new cosmetic ingredient based on phycocyanin incorporated into a high-lipid matrix, such as shea butter. A comprehensive characterization of the cytotoxicity and anti-inflammatory activity of this new bioactive phycocyanin–protein complex in human THP-1 monocytic cells was performed. For this purpose, cytocompatibility was evaluated using MTT assays at concentrations ranging from 10 to 0.0006% v/v. Anti-inflammatory activity was measured under LPS-induced inflammatory stress by measuring IL-6 and IL-8 secretion using ELISA in PMA-differentiated THP-1 cells treated with non-cytotoxic concentrations (0.04, 0.02, and 0.01% v/v). A crucial finding was the absence of anti-inflammatory activity at 0.01% v/v, indicating a minimum effective concentration threshold and, consequently, effective doses. The results of this research indicate that the phycocyanin and shea butter ingredients demonstrate strong cytocompatibility at relevant cosmetic doses and significant anti-inflammatory activity, supporting their suitability for formulations targeting skin sensitivity, erythema reduction, and post-inflammatory recovery. Full article

Microalgae and cyanobacteria represent an emerging and sustainable source of bioactive compounds for the food, cosmeceutical, and pharmaceutical sectors. In this study, the potential of two microalgae-cyanobacteria consortia, consortium 1 (C1) consisting of Chlorella vulgaris and Arthrospira platensis, and consortium 2 (C2) consisting of Kamptonema sp., Nannochloropsis oculata, Tetraselmis suecica, and Chlorella vulgaris, as a source of bioactive peptides was evaluated. Firstly, protein extraction from both biomasses was optimized by testing different protein solubilization and precipitation pHs, with pH 10 and pH 5 providing the best results in terms of protein recovery in both cases. Selected protein extracts, with protein contents of 28.50 ± 2.69% (C1) and 8.46 ± 0.45% (C2), were further hydrolyzed with Alcalase, evaluating the impact of the incubation time on peptide release and the antioxidant capacity of hydrolysates. A total of 1 h of hydrolysis proved to be enough for antioxidant capacity increase. In addition, in silico hydrolysis of the proteins identified with Alcalase in C1 and C2 (data are available via ProteomeXchange with identifier PXD077201 and PXD077149 for C1 and C2, respectively) was evaluated, assessing the potential bioactivity of the peptides produced, more specifically their antioxidant capacity. Our findings demonstrate that both microalgae-cyanobacteria consortia are valuable sources of bioactive compounds with antioxidant capacity, with potential interest as functional ingredients for the food, cosmeceutical, and pharmaceutical industries. Full article

Microalgae hold great potential towards pharmaceutical and nutraceutical sectors due to their substantial content of highly functional bioactive compounds. To assess their potential as a sustainable source of valuable products, 10 cyanobacterial and 10 eukaryotic microalgal strains belonging to different taxonomic groups (Chlorophyta, Cyanophyta, Euglenophyta, Heterokontophyta and Rhodophyta) were screened for their biochemical profile, antioxidant and antimicrobial activity against Staphylococcus aureus. Total phenol content and antioxidant activity were positively correlated (r = 0.69, p < 0.01), with the highest values observed in Euglena cantabrica, Haematococcus pluvialis, and Chrysoreinhardia giraudii. HPLC-PAD pigment analysis revealed species-specific profiles, with β,β-carotene as major carotenoid in most cyanobacteria, whereas neoxanthin, violaxanthin and lutein were predominantly present in Chlorophyta, and fucoxanthin was the main carotenoid in C. giraudii, Entomoneis sp. and Isochrysis galbana. Protein content ranged from 9.2 ± 0.4% to 57.6 ± 0.5% with the highest levels in the cyanobacteria Microcystis aeruginosa, Nostoc sp., Cylindrospermum stagnale, Anabaena minutissima, and Arthrospira platensis. Multivariate analysis differentiated cyanobacteria and eukaryotes based on their fatty acid profiles. Organic extracts from 15 species showed inhibitory effects against S. aureus with MIC50 < 1024 µg/mL. The eukaryotes Entomoneis sp., C. giraudii, I. galbana, Picochlorum sp. and the cyanobacteria C. stagnale and Nodularia sp. exhibited the strongest inhibitory effects on bacterial growth. In conclusion, E. cantabrica and C. giraudii stood out for their high antioxidant activity and significant antimicrobial effects, respectively, highlighting their potential as valuable sources of bioactive compounds. Full article

This study aimed to characterize the draft genome of Arthrospira platensis NH isolated in Vietnam and evaluate its phylogenetic position within cyanobacteria. Phylogenetic analysis based on 16S rRNA gene sequences confirmed that A. platensis NH belongs to the Arthrospira clade. The assembled genome comprises 5,548,511 bp and contains 4728 genes, including 4683 protein-coding sequences, 42 tRNA genes, and 3 rRNA genes. Genome mapping revealed conserved gene organization with an overall GC content of 44.45%. A comparative genomic analysis with other Arthrospira strains (A. platensis NIES-39 and C1) demonstrated high sequence conservation, supporting their close genetic relationships. Secondary structure prediction showed that all 42 tRNA types adopt typical cloverleaf structures, while the ribosomal RNA genes (16S, 23S, and 5S rRNA) exhibit conserved base composition. An analysis of 16S rRNA sequences from 13 cyanobacterial taxa identified 230 polymorphic sites, providing informative markers for phylogenetic divergence among genera. Collectively, these results establish a comprehensive genomic and phylogenetic framework for A. platensis NH and provide insights into its genetic relationships and potential biotechnological applications. Full article

Microplastics (MPs), particularly low-density polyethylene (LDPE), are widespread pollutants in aquatic environments and may affect cyanobacterial physiology. This study investigated the concentration-dependent effects of LDPE-MPs on the physiology and transcriptomic responses of Arthrospira platensis. Cultures were exposed to 10–5000 mg/L LDPE-MPs (nominal size ≤ 500 µm) for 16 days. Low to moderate concentrations (10–1000 mg/L) produced minimal effects on growth, biomass accumulation, or pigment contents. In contrast, higher concentrations (3000–5000 mg/L) were associated with reduced growth and biomass, accompanied by declines in chlorophyll a (Chl a) and phycobiliproteins over time. By day 16 at 5000 mg/L, biomass and Chl a decreased to 1.47 ± 0.03 g/L and 8.39 ± 0.24 µg/mL, respectively, compared with 1.64 ± 0.04 g/L and 10.81 ± 0.52 µg/mL in the control (p < 0.05). Accordingly, Chl a yield decreased by 13%. Field-emission scanning electron microscopy revealed adhesion of LDPE particles to filament surfaces and the formation of extracellular polymeric substance (EPS)-rich aggregates, which may influence light availability and nutrient exchange. Transcriptomic analysis indicated changes in several metabolic pathways, including nitrogen assimilation, photosynthetic electron transport, carbon metabolism, and metal homeostasis, together with differential expression of genes related to stress responses and EPS biosynthesis. Overall, these findings suggest that relatively high concentrations of LDPE microplastics may influence physiological and metabolic processes in A. platensis. Full article

(1): Endotoxins are components of Gram-negative bacteria. Uptake can induce allergies, nausea, or sepsis. These responses are triggered by an activation of the immune system. Endothelial cells, lining blood vessels, are the first to be exposed to circulating LPA. Activation can dramatically affect the blood system, such as the formation of thrombi. This study aimed to clarify whether the activation of primary human venous endothelial cells (HUVECs) by LPA could be reduced by the addition of an Arthrospira platensis (AP) extract. (2): HUVECs were cultured for 24 h in cell culture medium supplemented with different concentrations of AP (50, 100, 200 µg/mL). Then 2.5 µg/mL of LPA was added. Cell morphology, viability, cell proliferation, cell membrane integrity, cell metabolism, and cell function were examined after two and four days. (3): Treatment with LPA alone negatively affected HUVEC growth, viability, cell membrane integrity, and metabolic activity. Adding AP to the culture medium had a positive influence on these effects, with 100 µg/mL proving to be the most effective dose. (4): The results clearly revealed that an extract of AP has the potential to reduce the damage to the venous endothelium when exposed to lipopolysaccharides, in particular at a concentration of 100 µg/mL. Full article

Enriching bakery products with highly nutritious ingredients, such as microalgae and insect powder, is a promising strategy for developing functional foods. This study aimed to evaluate the effects of spirulina, chlorella, and cricket powder on the quality of sponge cakes. The assessed parameters included color, nutritional value, mineral composition, antioxidant activity, predicted glycemic index (pGI), and sensory properties. The addition of microalgae significantly reduced the L* value and altered the color shade of the sponge cakes, while the insect powder caused milder color changes. The enriched samples contained higher levels of protein (by up to 14%) and minerals, including calcium, magnesium, iron, and zinc. Antioxidant activity was enhanced across all variations, particularly in sponge cakes with insect powder, which showed the highest TPC (47.96 mg GAE), DPPH· (0.107 mM TE), and ABTS·⁺ (0.208 mM TE) levels. Cakes containing spirulina exhibited the highest total flavonoid content (63.95 mg EPI). Additionally, the enriched samples demonstrated a statistically significant reduction in the pGI. Among all the supplemented samples, the sponge cake with cricket powder received the highest consumer acceptance. Overall, enriching sponge cakes with microalgae and cricket powder improved their nutritional value and antioxidant properties, with insect powder offering the best balance between sensory quality and functionality. Full article

Daphnia magna exhibits reproductive plasticity, alternating between parthenogenesis and sexual reproduction with ephippia (resting eggs) formation under stressful conditions. This study evaluated food restriction or thermal stress as independent inducing factors of ephippia in two consecutive 60-day trials (one per treatment) under controlled conditions. In Trial I, neonates were fed Arthrospira platensis at 20 (control), 10 (moderate), or 0.5 (severe) mg L⁻¹ day⁻¹. In Trial II, neonates were maintained at 10, 15, 20, 25, and 30 °C with optimal feeding. Control food levels and temperatures of 20 °C promoted exclusive parthenogenesis, yielding up to 13,170 ± 515 neonates on treatment fed with 20 mg L⁻¹ of A. platensis day⁻¹. Conversely, severe restriction (0.5 mg L⁻¹ day⁻¹) suppressed asexual reproduction by 99.3% and maximized ephippia production (726 ± 10) over 60 days. Thermal extremes (10 and 30 °C) also induced ephippia formation, peaking at 30 °C (85 ± 7). Ephippia quality was stress-dependent: moderate restriction (10 mg L⁻¹ day⁻¹) yielded the highest proportion of twin-egg ephippia (82.3%) and hatching success (82%), whereas severe food restriction or high temperature (30 °C) increased quantity but reduced the viability of ephippia. These findings suggest independent thresholds for inducing sexual reproduction in D. magna. The study provides a standardized protocol for ephippia production with applications in aquaculture, ecotoxicology, and conservation purposes. Full article

Ischemia and reperfusion (IR) injuries may produce deleterious effects on hepatic tissue after liver surgery and transplantation. The consequences of IR are more evident in pathological steatotic livers. Spirulina (Arthrospira platensis) is known for its potential to modulate inflammatory responses and enhance antioxidant defenses. The current investigation assessed whether spirulina pretreatment mitigates hepatic IR injury exacerbated by steatosis in rats. Thirty male Wistar rats were divided into five groups: sham, IR, HFD, HFD + IR, and SP1000 (HFD + IR + spirulina 1000 mg/kg/day; oral gavage). Liver injury, oxidative stress, inflammatory signaling, and inflammasome/pyroptosis-related markers were assessed using serum transaminases, hematoxylin–eosin staining, immunofluorescence, and qRT-PCR. High-fat diet-fed rats developed steatosis, which significantly worsened IR-induced liver damage, as shown by the respective steatosis histological score, the elevated alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and higher expression of inflammatory markers, including Toll-like receptor (TLR4), nuclear factor kappa B (NF-κB), tumor necrosis factor alpha (TNF-α), and interleukin-1 beta (IL-1β) and inflammasome/pyroptosis-related transcripts, namely NOD-like receptor family pyrin domain-containing 3 (NLRP3), interleukin-18 (IL18), and gasdermin D (GSDMD). Oxidative stress was exacerbated, as reflected by higher levels of malondialdehyde (MDA) and reduced antioxidant defenses (superoxide dismutase (SOD) activity, reduced glutathione (GSH) content, glutathione peroxidase (GPx) expression, and heme oxygenase-1 (HO-1) expression). Furthermore, HFD + IR upregulated sterol regulatory element-binding protein-1c (SREBP-1c) expression and downregulated AMP-activated protein kinase (AMPK) expression. Spirulina supplementation significantly attenuated liver injury and transaminase release, reduced MDA, restored antioxidant parameters, downregulated inflammatory and inflammasome-related gene expression, and shifted both SREBP-1c and AMPK expressions toward control levels. Full article