Search Results (820)

Green synthesis has emerged as a sustainable alternative to conventional nanoparticle production by utilizing biological resources as reducing and stabilizing agents. In this study, extracts of Chlorella vulgaris cultured at different incubation temperatures and light periods were evaluated for their total phenolic content, total flavonoid content, and antioxidant capacity to identify the most suitable extract for the green synthesis of zirconium dioxide (ZrO₂) nanoparticles. The extract prepared at 25 °C under a 12 h light/12 h dark photoperiod exhibited the highest antioxidant activity and flavonoid content and was selected for nanoparticle synthesis. ZrO₂ nanoparticles were successfully synthesized using a green approach and characterized by dynamic light scattering (DLS), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-Ray diffraction (XRD). DLS analysis revealed hydrodynamic particle sizes ranging from 419 to 570 nm with polydispersity index values between 0.27 and 0.44. FTIR analysis confirmed the formation of ZrO₂ through characteristic Zr–O and Zr–O–Zr vibrational bands, while SEM images demonstrated predominantly spherical particles with a heterogeneous size distribution. The synthesized nanoparticles retained considerable phenolic and flavonoid contents and exhibited enhanced antioxidant activity compared with the corresponding algal extracts. Furthermore, the nanoparticles demonstrated broad-spectrum antibacterial activity against both Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria, as well as antifungal activity against Candida albicans and Saccharomyces cerevisiae. Nanoparticles synthesized by incubation at 40 °C for 12 h showed the strongest antimicrobial activity. These findings demonstrate that cultivation conditions of C. vulgaris and the synthesis conditions of the nanoparticles significantly influence nanoparticle properties and biological activity, highlighting the potential of microalgae-mediated green synthesis for developing environmentally friendly antimicrobial nanomaterials. Full article

Microalgae are promising platforms for biomass production, carbon capture, biofuels, and high-value bioproducts. However, despite significant advances in cultivation technologies, reactor engineering, and metabolic engineering, industrial implementation remains limited. This gap suggests that the main challenge of microalgae biotechnology lies not in the availability of productive strains or cultivation systems, but in managing the environmental and physiological heterogeneity that emerges during scale-up. This structured narrative review selected literature using predefined descriptors and relevance-based inclusion criteria and organized the evidence into five thematic domains encompassing cultivation-scale constraints, cellular physiology, bioengineering, precision technologies, and industrial translation. This review examines macrospatial bottlenecks related to light distribution, gas transfer, hydrodynamics, and reactor operation, alongside microspatial constraints involving cell cycle regulation, carbon allocation, metabolic adaptation, and stress responses. Recent advances in adaptive cultivation, real-time monitoring, artificial intelligence, digital twins, computational modeling, and bioengineering are discussed as tools to transform biological and environmental variability into actionable information. Based on concepts established in precision agriculture, this review proposes precision microalgae as a conceptual framework that integrates reactor engineering and cell physiology with three operational pillars: real-time monitoring, predictive modeling, and adaptive control. Its specific contribution is to connect currently fragmented technological and biological advances within a common framework for managing multiscale heterogeneity during cultivation and scale-up. Overall, the available evidence supports the operational logic of this framework, although its generalized effectiveness under industrial conditions remains to be demonstrated. Full article

Microalgae facade systems have emerged as an innovative approach in sustainable architecture, offering benefits in energy efficiency, carbon reduction, and biomass production. However, research remains fragmented across biotechnology, environmental engineering, and architectural design, with limited synthesis of its intellectual structure and thematic evolution. This study presents a bibliometric and thematic analysis of microalgae facade research in buildings from 2016 to 2025 using a combined Web of Science and Scopus dataset of 59 publications. The analysis examines publication trends, influential authors, journals, collaboration networks, and key research themes, while science mapping identifies conceptual clusters and their evolution. A sustainability-oriented perspective further links these themes to the environmental, economic, and social dimensions of sustainability and the United Nations Sustainable Development Goals (SDGs). The findings show that research has primarily focused on photobioreactor technologies, energy performance, and biomass production, whereas architectural integration and real-world building applications remain underexplored. Although interdisciplinary collaboration has increased in recent years, the field is still at an early stage of development. This study provides a systematic overview of the current intellectual landscape, identifies research gaps, and offers directions for advancing microalgae facade technologies toward sustainable and net-zero built environments. Full article

Coastal green tides may alter nearshore bioaerosols through coupled marine, atmospheric, and meteorological processes, yet their effects on airborne microbial communities remain poorly resolved. Atmospheric samples were collected in Aoshan Bay, Qingdao, China, during five phases of the Ulva prolifera green tide in 2019 (pre-bloom, 19 April; early bloom, 15 June; middle bloom, 15 July; late bloom, 6 August; post-bloom, 30 August); seawater samples were collected at one nearshore site on each of the five sampling dates, with microbial sequencing performed for the middle-bloom (15 July) and late-bloom (6 August) phases. Bacterial and fungal communities were characterized; although bioaerosols may also contain microalgae and viruses, this study profiled only the bacterial and fungal fractions, using bacterial 16S rRNA gene (V3-V4 region) and fungal internal transcribed spacer (ITS2) amplicon sequencing and evaluated together with meteorological variables, air-pollutant concentrations, and 72-h backward air-mass trajectories. Proteobacteria dominated the airborne bacterial assemblages (81.28–97.83%), with Sphingomonas as the most abundant genus (47.85–89.84%). Basidiomycota and Ascomycota dominated the fungal assemblages, whereas Cryptococcus and Alternaria were the major fungal genera. Community richness and composition varied across bloom phases. Chytridiomycota was undetected before the bloom (0%), appeared after bloom onset, and reached its highest relative abundance during the middle phase (8.19%). Spatial patterns indicated joint terrestrial and marine influences, although bacterial communities in seawater and air remained highly dissimilar. Temperature, relative humidity, particulate matter, ozone, and air-mass origin were associated with changes in microbial diversity and composition. These findings provide an observational baseline for coastal bioaerosol dynamics during a macroalgal green tide, extending the HAB–bioaerosol literature—which has focused predominantly on cyanobacterial blooms—to a large green macroalga. Bacteria and fungi showed contrasting environmental responses: bacterial richness increased with temperature, whereas fungal diversity declined. Greater compositional similarity between seawater and air for fungi than for bacteria suggests differential environmental filtering at the air–sea interface and implies that multiple source pathways—direct aerosolization, sea-surface release, and in-situ atmospheric production—may differentially shape the two domains. Given the single-date-per-phase sampling design, the absence of sequenced laboratory contamination controls, and the lack of absolute abundance data, these results should be regarded as preliminary and hypothesis-generating, underscoring the need for ASV-level source tracking, controlled chamber experiments, and replicated multi-year designs in future assessments of bloom–atmosphere interactions. Full article

Widespread environmental contamination by per- and poly-fluoroalkyl substances (PFAS) has driven the phaseout of traditional long-chain compounds; however, the toxicity of their highly mobile, short-chain replacements to aquatic microorganisms remains less well characterized. This study compared the toxicity of perfluoroalkyl carboxylic acid (PFCA): long-chain perfluorooctanoic acid (PFOA, C8) and the short-chain perfluorobutanoic acid (PFBA, C4) in two structurally distinct microalgae, Prymnesium parvum and Chlorella sorokiniana. P. parvum was more sensitive to PFAS exposure than C. sorokiniana, with significant growth inhibition occurring at 25–50 mg/L and complete mortality at 100 mg/L, whereas C. sorokiniana exhibited significant effects at concentrations ≥200 mg/L. PFBA exhibited greater toxicity than PFOA in both species, with IC₅₀ values of 25.81 and 64.30 mg/L, respectively, in P. parvum and 101.4 and 277.1 mg/L, respectively, in C. sorokiniana. PFBA induced reactive oxygen species (ROS) generation, lipid peroxidation, and significantly increased in cell volume and chlorophyll content in P. parvum, whereas C. sorokiniana exhibited oxidative responses primarily at higher concentrations and no significant changes in cell dimensions or chlorophyll content. The responses indicate that oxidative stress is an important component of PFCA toxicity and sensitivity differs substantially between microalgal species. The contrasting responses may be associated with differences in cellular structure and physiology, although the underlying mechanisms require further investigation. Overall, PFCA toxicity was both compound- and species-dependent, and the greater toxicity of PFBA under the tested conditions demonstrates that short-chain replacement PFCAs should not be assumed to have lower biological toxicity than their long-chain counterparts. Full article

Anthropogenic pollution of aquatic ecosystems presents a significant global challenge, underscoring the urgent need for resilient, biologically mediated remediation strategies. In this context, microalgae have emerged as a compelling solution, owing to their inherent adaptability to diverse environments and their capacity for efficient contaminant mitigation through bioremediation. These organisms possess the potential to sequester and remove a broad spectrum of pollutants from wastewater streams, including excess nutrients, organic substrates, heavy metals, and various emerging contaminants. Specifically, their metabolic versatility allows these microorganisms to tolerate and degrade complex substances such as recalcitrant micropollutants and hydrocarbons even under fluctuating environmental conditions. This review evaluates extremophilic microalgae as specialized biological agents capable of functioning under harsh anthropogenic stressors that may constrain the performance of microalgal strains commonly investigated for wastewater treatment. Their distinctive stress tolerance may provide advantages for treating wastewater characterized by extreme physicochemical conditions. By examining the unique metabolic pathways of these extremophiles, this analysis addresses critical gaps in the current bioremediation literature regarding the practical scalability and economic viability of integrating such specialized biomass into large-scale treatment infrastructure. Full article

Rising temperatures and the occurrence of heat waves due to climate change can increase the risk of various skin disorders. Moreover, elevated temperatures worsen oxidative damage and inflammation caused by other climate change stressors, such as UV exposure. Consequently, there is growing interest in innovative solutions to protect skin health from the effects of pollution and climate change stressors. Among natural cosmeceuticals, carotenoids are recognized for their antioxidant and anti-inflammatory properties. This study evaluated the thermoprotective effects of Hematococcus lacustris (the microalga formerly called Hematococcus pluvialis) extract (HLE), which is considered the richest natural source of carotenoid astaxanthin, against acute hyperthermia, which mimics the conditions of heat waves. In addition, we separately assessed the effects of HLE against UVA and hydrogen peroxide stress, complementing the antioxidant profile of the extract under study. The evaluation was conducted using in vitro tests on human HaCaT keratinocytes and the nematode Caenorhabditis elegans, which is a model organism sensitive to environmental stressors. The treatment of HaCaT keratinocytes with HLE counteracted the intracellular formation of reactive oxygen species and cytotoxicity induced by hyperthermia, UVA, and hydrogen peroxide exposure. Under the same experimental conditions, HLE also restored the impaired expression of stress-sensitive genes, such as matrix metalloproteinase-1, in HaCaT keratinocytes and promoted wound closure mimicking the process of re-epithelization. Lastly, experiments in C. elegans confirm that HLE reduces heat stress-induced oxidative damage and preserves motility, supporting a systemic protective effect consistent with dietary uptake of the extract. These findings suggest that HLE, rich in carotenoid astaxanthin, can protect keratinocytes against oxidative damage and cytotoxicity induced by thermal stress, indicating its potential role in mitigating thermal aging. Full article

Heavy metal pollution in water bodies is a serious environmental and public health concern, as these contaminants are toxic, persistent and bioaccumulative in ecosystems and human tissues. Conventional remediation technologies are expensive, require constant monitoring and do not fully remove them. Recent studies have shown the potential, sustainability and cost-effectiveness of biosorption using algal biomass. This review gives a detailed assessment of the potential of algae and cyanobacteria as cheap biosorbents for the removal of heavy metals from wastewater. The sorption efficiency of algae and cyanobacteria is critically evaluated in terms of important operating parameters such as pH, temperature, initial metal concentrations, biomass loading and contact time. The diversity of metal-binding functional groups such as carboxylate, amine, imidazole, phosphate, sulfhydryl, sulfate and hydroxyl groups present on the surface of algal cells is discussed in detail, highlighting the complex algal biochemistry. Recent developments in functionalized algal materials are also discussed, with emphasis on their potential to improve adsorption capacity, selectivity, regeneration, and practical applicability. However, this review also identifies some limitations such as energy requirements for the drying of biomass, limitations of batch systems for microalgae applications, and challenges for large-scale implementation. Future research directions are suggested to highlight the urgent need for functionalized algal materials, optimization of large-scale applications, and integration of biosorption with other treatment technologies in the framework of a circular economy. Full article

Marine macroalgae represent abundant, renewable reservoirs of structurally unique bioactive compounds, such as sulfated polysaccharides, phlorotannins, and carotenoids, with immense potential for sustainable functional foods. However, their industrial exploitation is severely bottlenecked by complex, repeat-rich genomes, recalcitrant genetic transformation tools, and environmental cultivation variability. Synthesizing evidence from 180 high-quality studies spanning from 1961 to 2026, this review provides a comprehensive synthesis of how artificial intelligence (AI) and synthetic biology may contribute to overcoming these challenges. We highlight key advances across the bioengineering pipeline, including the application of metabolic engineering strategies for enhancing valuable compound production in engineered algal systems. For example, a CrtYB-based metabolic engineering approach achieved β-carotene accumulation of 22.8 mg/g in the microalga Chlamydomonas reinhardtii, providing important insights for future metabolic engineering of marine macroalgae. In addition, AI-assisted approaches show promising potential for enzyme discovery, metabolic pathway prediction, and multi-omics-guided optimization of bioactive compound production. We further discuss critical downstream challenges, including the low gastrointestinal absorption (~14%) and extensive metabolic transformation of seaweed-derived phenolic compounds, as well as the potential application of AI-integrated physiological modeling for improving bioavailability prediction and safety assessment. This review provides a pioneering, data-driven synthesis of how the convergence of AI and synthetic biology is overcoming these roadblocks. Moving beyond generic descriptions, we highlight key empirical milestones across the bioengineering pipeline, including multi-fold yield enhancements in target pigments (up to 22.8 mg/g) and the AI-driven discovery of novel polysaccharide-degrading enzymes. Furthermore, we confront critical downstream challenges, specifically addressing the characteristically low (~14%) gastrointestinal absorption bottleneck and extensive metabolic biotransformation of seaweed phenolics. We demonstrate that integrating digital twins with reinforcement learning-driven physiologically based pharmacokinetic (PB-PK) modeling can compress the R&D cycles of these seaweed functional ingredients by over 60%. Unlike previous reviews that treat these technologies as independent entities, this article proposes a macroalgae-focused approach that delivers a unique, macroalgae-specific computational and experimental framework, providing a future roadmap toward intelligent smart marine biotechnology and sustainable development to drive the global blue bioeconomy. Full article

In this article, Life Cycle Assessment (LCA) was applied to investigate the potential environmental impacts of bioethanol production pathways from six biomass feedstock options. The LCA cradle-to-gate modelling case studies involve (i) corn stover, (ii) wheat straw, (iii) rice straw, (iv) sugarcane bagasse, (v) woody biomass, and (vi) microalgae for the final production of 1 kg bioethanol as functional unit. Environmental impact results of GWP (Global Warming Potential), AP (Acidification Potential), and EP (Eutrophication Potential) were evaluated utilizing CML2001, a Life Cycle Impact Assessment (LCIA) methodology featuring midpoint evaluation and baseline environmental categories. Water Footprint (WF) indicators were also measured. Among the six feedstocks, the GWP results indicated the most favourable option to decarbonize bioethanol production is to utilize corn stover feedstock, enabling total-1.04 kg CO₂-eq/kg ethanol. Wood waste also displays favourable GWP impacts of −0.9 kg CO₂-eq/kg ethanol, along with negligible WF results. Both rice straw and microalgae exhibited the most unfavourable feedstock options, both resulting in GWP impacts of 12.71 kg CO₂-eq/kg ethanol and 11.32 kg CO₂-eq/kg ethanol respectively. Additionally, rice straw and microalgae require high volumes of WF during cultivation stages. Overall, the set of environmental impact results, based mostly on data derived from lab-scale or pilot scale reports, demonstrated substantial requirements for environmental reduction and management of some specific feedstocks to proceed for large scale set ups. Full article

In this study, quince-derived biochar was employed as a sustainable and multifunctional material for the removal of organic pollutants through different treatment alternatives depending on the pH (natural or modified), including adsorption and electro-Fenton degradation processes. The biochar, obtained by pyrolysis (500 °C, 14 h) of quince (Cydonia oblonga) biomass, exhibited a high intrinsic iron content (1296 mg/kg), which contributed to its electroactive properties and catalytic potential. Batch experiments demonstrated highly efficient adsorption of the target pollutant, the antibiotic sulfamethoxazole, achieving a maximum retention capacity of 35.51 mg/g. Regarding the degradation pathway, the electrochemical treatment achieved significant degradation rates under mild operating conditions, reaching total removal in less than 90 min. Both treatment options, under their respective optimal conditions, were subsequently evaluated using tertiary wastewater from a wastewater treatment plant, achieving good removal efficiencies exceeding 60% within 120 min. Finally, the treated effluent under optimal conditions was subjected to an ecotoxicity assay using the microalga Raphidocelis subcapitata, confirming the effectiveness of the treatment and the absence of harmful effects on this key microorganism in the aquatic food chain. These findings highlight the potential of iron-rich quince biochar as a low-cost and environmentally friendly material for various water treatment applications. Moreover, the results provide a promising approach for valorizing agricultural waste with inherent metallic content in heterogeneous electro-Fenton. Full article

Lead (Pb) is a persistent environmental contaminant that poses a significant risk to aquatic primary producers by disrupting photosynthesis, cellular metabolism, and physiological homeostasis. This study investigated the physiological and biochemical responses of two freshwater green microalgae, Mucidosphaerium pulchellum and Micractinium pusillum, exposed to Pb(II) concentrations ranging from 0 to 30 mg L⁻¹. Species-specific responses were evaluated through growth kinetics, chlorophyll fluorescence, lipid accumulation, and fatty acid profiling to elucidate mechanisms underlying Pb stress tolerance. Pb(II) exposure resulted in concentration-dependent inhibition of growth and photosynthetic activity in both species, with marked reductions in quantum yield and increases in photosynthetic inhibition at the highest exposure concentration (30 mg L⁻¹), reaching approximately 95% in M. pulchellum and 93% in M. pusillum. Lipid metabolism exhibited distinct species-specific responses: M. pulchellum showed a progressive decline in total lipid content, whereas M. pusillum exhibited enhanced lipid accumulation under moderate Pb exposure followed by depletion under severe stress. Fatty acid analysis revealed significant membrane lipid remodeling, characterized primarily by reductions in polyunsaturated fatty acids, particularly α-linolenic acid (C18:3), with stronger alterations observed in M. pulchellum. These findings demonstrate that Pb toxicity involves interconnected effects on photosynthetic efficiency, carbon allocation, and membrane lipid composition, with species-specific differences in physiological resilience. The combined application of chlorophyll fluorescence and lipid-related biomarkers provides a sensitive approach for assessing heavy-metal stress responses and improving understanding of Pb tolerance mechanisms in freshwater microalgae. These findings provide a physiological basis for the development of sustainable biomonitoring approaches for freshwater ecosystems. Full article

The Murmansk Region (the Russian Arctic) faces severe environmental degradation due to heavy metal (HM) pollution from copper–nickel smelting, resulting in vast industrial barrens with elevated concentrations of copper (Cu) and nickel (Ni). Conventional phytostabilization methods are often ineffective or costly, necessitating alternative bioremediation strategies. This study evaluates the potential of microalgae and cyanobacteria for revegetating HM-contaminated substrates. Six strains of Nostoc-like morphotypes and three green microalgae were tested for Cu²⁺ tolerance (0.5–15 mg/L). While most strains exhibited growth inhibition at ≥3 mg/L Cu²⁺, Atlanticothrix sp. KPABG-154445, isolated from Tolbachik Volcano, showed positive growth at 2 mg/L Cu²⁺ under the tested conditions and recovering metabolic activity post-exposure. In sorption experiments, non-viable biomass achieved 68% Cu²⁺ removal at 2 mg/L, outperforming actively growing cultures. A microcosm experiment using copper-spiked nepheline slime (simulating mining waste) revealed Atlanticothrix sp. KPABG-154445’s ability to colonize nutrient-poor substrates, forming biocrusts covering 42% of the surface within one month, even under Cu²⁺ contamination (10 mg/kg). These findings highlight cyanobacteria, particularly strains such as KPABG-154445, as promising agents for the bioremediation of Arctic industrial barrens, leveraging their dual capacity for heavy metal tolerance and biocrust formation. Full article

Interactions between cyanobacteria and eukaryotic algae are traditionally viewed as favoring cyanobacteria, which are often the dominant competitors in freshwater ecosystems. However, increasing evidence suggests that eukaryotic algae also possess effective chemical defenses capable of suppressing cyanobacterial proliferation. In this study, the anti-cyanobacterial potential of a methanolic biomass extract of the green microalga Chlorella vulgaris against the bloom-forming cyanobacterium Microcystis aeruginosa was investigated. Optical density measurements revealed the inhibition of cyanobacterial growth, with extract concentrations of 0.4–1.6 mg mL⁻¹ significantly reducing biomass accumulation. The lowest concentration (0.2 mg mL⁻¹) stimulated the accumulation of phycobiliproteins, whereas concentrations of 0.8–1.6 mg mL⁻¹ significantly decreased phycobiliprotein content, indicating progressive physiological impairment. The results suggest that the highest extract concentration applied may also cause alteration in phosphate acquisition. Lipid profiling of the Chlorella biomass showed that 97% of the extractable lipids consisted of methanol-soluble fatty acids, with C18 fatty acids predominating among the 20 identified compounds. These metabolites are reported to possess allelopathic activity and therefore represent plausible contributors to the observed inhibition. These findings support that anti-cyanobacterial activity may represent a widespread ecological trait of Chlorella and potentially other green microalgae, providing a promising foundation for environmentally friendly cyanobacterial bloom management. Full article

The pet food industry is undergoing a significant transformation, driven by the growing trend of companion animal humanization and increasing concerns over the environmental sustainability of conventional protein and lipid sources. Consumers now seek diets that not only meet basic nutritional requirements but also offer preventive health benefits. Microalgae, including Arthrospira (Spirulina, a kind of cyanobacterium), Chlorella, Schizochytrium, and Euglena gracilis, have emerged as versatile biological platforms capable of addressing both functional and sustainability challenges. These microorganisms produce high-quality proteins, omega-3 long-chain polyunsaturated fatty acids (particularly docosahexaenoic acid, DHA), natural pigments, and immunomodulatory polysaccharides. This review synthesizes findings from peer-reviewed studies on the application of microalgae in pet nutrition, covering dogs, cats, and aquatic companion animals. We examine how algal ingredients influence gut microbiota, for instance, by enriching beneficial genera such as Turicibacter and Peptococcus, enhance vaccine responses and mucosal immunity, support cognitive function in aging pets, and contribute to weight management. Particular attention is given to Euglena gracilis and its paramylon (β-1,3-glucan), a pathogen-associated molecular pattern that engages the Dectin-1 pathway to train innate immunity and has demonstrated antiviral activity through host defense mechanisms. The review also surveys the patent landscape, highlighting trends in palatability enhancement, hypoallergenic formulations, and novel delivery formats. Key challenges remain, including ingredient standardization, safety validation, palatability optimization, and consumer acceptance. We outline a translational roadmap that prioritizes well-designed clinical trials in target species and processing methods that preserve bioactivity. Collectively, the evidence positions microalgae, and Euglena gracilis in particular, as promising candidates for next-generation functional pet foods that deliver health benefits alongside ecological sustainability. Full article