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Background: Fractionation of microalgal cells has important applications in producing pharmaceuticals and treating diseases. Multiple types of microalgal cells generally coexist in the oceans or lakes and are easily contaminated by microplastics and bacteria. Therefore, it is of paramount significance to develop an effective fractionation approach for microalgal cells for biological applications. Counter-rotating induced-charge electro-osmotic (ICEO) eddies present unique advantages in separating microalgal cells for flexible electrode extension fashion and profile regulation manner. Enthused by these, we proposed a contact-free microfluidic approach for the fractionation of microplastics, bacteria, and microalgae with extensible counter-rotating ICEO eddies., Results: Firstly, we investigated the flow-field distribution actuated by counter-rotating ICEO eddies, the influence of working parameters on the fluid velocity, and the effect of particle sizes and charges on particle separation. Secondly, depending on the investigation of the movement of microparticles and microalgal cells, we explored synthetic effects of flow rate, voltage, and frequency on the fractionation of microalgal cells from microplastics with an efficiency of about 100 %. Thirdly, this method was used to remove the bacteria for pure Dunaliella salina with a purity of about 95.24 %. Fourthly, this approach was engineered in the fractionation of Diatoms, Chlorella, and Dunaliella salina, and the influence of voltage and frequency on the purity of microalgae was studied. Finally, we proposed a multi-stage separation of microalgal cells with extended counter-rotating ICEO eddies and obtained an efficiency of 91.00 % in the first stage and a purity of 91.55 % and 90.48 % in the second stage., Significance: This contact-free method holds good potential in the selection of target microalgal cells to address the tricky issues of chronic wound treatment with the advantage of flexible electrode extension fashion and profile regulation manner., Competing Interests: Declaration of competing interest There are no conflicts to declare., (Copyright © 2024. Published by Elsevier B.V.)

We developed a stepwise method to transform Chlorella sorokiniana microalgal biomass into a potent biostimulant. The method, including maceration, high-pressure homogenization, and enzymatic hydrolysis, preserves the bioactive properties of the biomass as a biostimulant while minimizing plant inhibitory effects. Fractions were characterized individually, and optimal concentrations were determined using a rapid Arabidopsis root assay. A blend of optimal concentrations of fractions was identified as the most stimulating extract, increasing the root elongation by 25 %. When applied to tomato plants and monitored using high-throughput plant phenotyping, the blend displayed a 25 % reduction in mineral fertilizer use. Metabolomic analysis of the tomato plants showed significantly enhanced carbon and nitrogen metabolism in the leaves. Our findings indicate that the stepwise processing not only produces an effective biostimulant but also generates substantial residual biomass for a potential multiproduct biorefinery approach that can improve the overall techno-economic outlook., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The discharge of aquaculture wastewater, comprising nitrogen, phosphorus, heavy metals, and antibiotics from large-scale aquaculture, poses a significant threat to marine ecosystems and human health. Consequently, addressing the treatment of marine aquaculture wastewater is imperative. Conventional physicochemical treatment methods have various limitations, whereas microalgae-based biological treatment technologies have gained increasing attention in the field of water purification due to their ability to efficiently absorb organic matter from mariculture wastewater and convert CO₂ into biomass products. Microalgae offer potential for highly efficient and cost-effective mariculture wastewater treatment, with particularly noteworthy advancements in the application of combined microalgae technologies. This paper explores the research hotspots in this field through bibliometric analysis and systematically discusses the following aspects: (1) summarizing the current pollution status of mariculture wastewater, including the types and sources of pollutants in various forms of mariculture wastewater, treatment methods, and associated treatment efficiencies; (2) analyzing the factors contributing to the gradual replacement of single microalgae technology with combined microalgae technology, highlighting its synergistic effects, enhanced pollutant removal efficiencies, resource recovery potential, and alignment with sustainable development goals; (3) exploring the mechanisms of pollutant removal by combined microalgae technologies, focusing on their technical advantages in bacterial-algal coupling, immobilized microalgae systems, and microalgal biofilm technologies; (4) discussing the challenges faced by the three main categories of combined microalgae technologies and proposing future improvement strategies to further enhance their application effectiveness. In conclusion, this paper offers a detailed analysis of these emerging technologies, providing a forward-looking perspective on the future development of microalgae-based mariculture wastewater treatment solutions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Nostoc sphaeroides, originally discovered in selenium-rich fields, is a photosynthetic, nitrogen-fixing cyanobacterium that forms edible spherical macrocolonies. However, prolonged selenium supplementation negatively impacts colony quality in culture. To address this, a two-phase cultivation strategy was developed to spatiotemporally separate biomass accumulation from selenium enrichment, resulting in high-quality selenium-enriched N. sphaeroides colonies. The first phase focused on colony growth in nitrogen-free BG-11 0 medium, while the second phase emphasized selenium enrichment in selenium-supplemented, phosphorus-reduced, and nitrogen-containing BG-11 medium ("selenium enrichment medium"). Scale-up to 300 L confirmed the robustness of this process, achieving desired colony hardness of ∼3 newtons, selenium content of ∼350 μg/g, and yield of ∼0.5 g/L (dry weight). Additionally, polysaccharides containing ∼110 μg/g selenium were isolated from the colonies, exhibiting biochemical properties similar to selenium-free polysaccharides from control colonies. These results provide valuable insight into the potential of N. sphaeroides as a cell factory chassis for producing selenium bioproducts., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Optimal control and process optimization of astaxanthin production from Haematococcuslacustris is directly linked to its complex cell cycle ranging from vegetative green cells to astaxanthin-rich cysts. This study developed an automated online monitoring system classifying four different cell cycle stages using a scanning microscope. Decision-tree based machine learning and deep learning convolutional neural network algorithms were developed, validated, and evaluated. SHapley Additive exPlanations was used to examine the most important system requirements for accurate image classification. The models achieved accuracies on unseen data of 92.4 and 90.9%, respectively. Furthermore, both models were applied to a photobioreactor culturing H.lacustris, effectively monitoring the transition from a green culture in the exponential growth phase to a stationary red culture. Therefore, online image analysis using artificial intelligence models has great potential for process optimization and as a data-driven decision support tool during microalgae cultivation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

The study aimed to investigate the influence of different microalgae used in green water culture on the intestinal morphology of the seahorse Hippocampus reidi during the first 15 days of life. Four treatments were tested in triplicate, consisting of two microalgae (Tisochrysis lutea-ISO and Chaetoceros muelleri-CHO), used either individually (TISO and TCHO) or combined (TIC 1:1) in larval rearing water, and a treatment without microalgae (TWM). Larvae (6.68 ± 0.55 mm) were fed copepods (Parvocalanus crassirrostris; 2 ind mL -1 ) and rotifers (Brachionus rotundiformis; 8 ind mL -1 ) from the first to the seventh day, and from the eighth day onwards, with Artemia sp. nauplii (2 ind mL -1 ). For the analysis of intestinal histomorphometry, histological analysis of the tissue was performed on day 0 (initial) and after 7 and 15 days. The results demonstrate a significant increase in weight and weight gain of the larvae on the 15th day in the treatments with the addition of the microalgae T. lutea, whether alone or combination with other microalgae, compared to TWM. In relation the intestinal histomorphometry of larvae, the ANCOVA revealed that, on the 7th and 15th day, only the treatments with microalgae significantly affected the surface area of the intestinal villi. The intestinal histomorphometry of larvae from TISO showed higher values of villus height (85.29 ± 1.23 µm 2 ) compared to TWM (69.42 ± 2.82 µm 2 ) and TCHO (76.92 ± 2.23 µm 2 ) (P < 0.05) but did not show significant differences compared to TIC (80.127 ± 2.08 µm 2 ), which reflected on the villi surface area. Therefore, larvae from TISO (3603.43 ± 151.31 µm 2 ) and TIC (3550.29 ± 120.99 µm 2 ) showed significantly higher values of this parameter compared to TWM (3026.79 ± 147.64 µm 2 ) and TCHO (3069.09 ± 126.18 µm 2 ) (P < 0.05). In conclusion, the protocol for H. reidi larvae rearing in a green water system with the addition of the microalgae T. lutea resulted in an increase in the intestinal absorption area, resulting in improved performance of the larvae., Competing Interests: Declarations. Ethics approval: All animal procedures were carried out in accordance with the Guideline for the Care and by the National Council for Control of Animal Experimentation (CONCEA), and was approved by the Ethics Committee on Animal Use of the Federal University of Santa Catarina (CEUA/UFSC). Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Dopamine (DA) has attracted attention because of its effects on Haematococcus lacustris biomass, astaxanthin production, and physiological responses. The alga treated with 25 μM DA combined with 1 g L -1 sodium chloride exhibited 7.63 %, 41.25 %, and 52.04 % increases in biomass (1.41 g L -1 ), astaxanthin content (32.37 mg/g), and astaxanthin productivity (3.51 mg L -1 d -1 ) respectively, compared with the salinity stress and high light. Exogenous DA treatment promoted lipid synthesis while reducing carbohydrate and protein contents. Moreover, carotenogenesis and lipogenesis-associated genes were upregulated under DA induction. Inhibition of reactive oxygen species and autophagy, along with mitogen-activated protein kinase activation, promoted astaxanthin accumulation under DA. Furthermore, DA application boosted astaxanthin biosynthesis by regulating the levels of respiratory metabolic intermediates, the γ-aminobutyric acid shunt, and important phytohormones. These findings present a potential and successful biotechnological approach for enhancing biomass and astaxanthin production in H. lacustris under stressful conditions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The development of sustainable and controlled microalgae bioprocesses relies on robust and rapid monitoring tools that facilitate continuous process optimization, ensuring high productivity and minimizing response times. In this work, we analyse the influence of medium formulation on the growth and productivity of axenic Phaeodactylum tricornutumcultures and use the resulting data to develop machine learning (ML) models based on spectroscopy. Our culture assays produced a comprehensive dataset of 255 observations, enabling us to train 55 (24+31) robust models that predict cells or fucoxanthin directly from either absorbance or 2D-fluorescence spectroscopy. We demonstrate that medium formulation significantly affects cell and fucoxanthin concentrations, and that these effects can be effectively monitored using the developed models, free of overfitting. On a separate data subset, the models demonstratedhigh accuracy (cell: R 2  = 0.98, RMSEP = 2.41x10 6 cells/mL; fucoxanthin: R 2  = 0.91 and RMSEP = 0.65 ppm), providing a practical, cost-effective, and environmentally friendly alternative to standard analytical methods., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Low protein content under heterotrophic conditions limits the industrial production of proteins by microalgae. In this study, Graesiella emersonii WBG-1 efficiently synthesized and accumulated proteins (64.03%) under heterotrophic conditions, distinguishing it from other microalgae. Integrated transcriptome and proteome analyses revealed that genes and proteins associated with the photosynthetic system were significantly upregulated under heterotrophic culture compared to photoautotrophic and mixotrophic conditions. Nitrogen assimilation was enhanced while carbohydrate and fatty acid biosynthesis were restricted, carbon redirected towards amino acid and protein synthesis. Ribosome biogenesis was strengthened, and translation initiation and elongation factors were upregulated, increasing the translational activity of algal cells and promoting overall protein synthesis. Overall, these findings elucidate the mechanisms underlying efficient protein synthesis in G. emersonii WBG-1 under heterotrophic conditions, offering new insights and complementary perspectives on the regulation of protein synthesis in microalgae across different nutritional modes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Marine microalgae demonstrate a notable capacity to adapt to high CO 2 and warming in the context of global change. However, the dynamics of their evolutionary processes under simultaneous high CO₂ and warming conditions remain poorly understood. Here, we analyze the dynamics of evolution in experimental populations of a model marine diatom Phaeodactylum tricornutum. We conducted whole-genome resequencing of populations under ambient, high-CO 2 , warming and high CO 2  + warming at 2-yr intervals over a 4-yr adaptation period. The common genes selected between 2- and 4-yr adaptation were found to be involved in protein ubiquitination and degradation and the tricarboxylic acid (TCA) cycle, and were consistently selected regardless of the experimental conditions or adaptation duration. The unique genes selected only by 4-yr adaptation function in respiration, fatty acid, and amino acid metabolism, facilitating adaptation to prolonged high CO 2 with warming conditions. Corresponding changes at the metabolomic level, with significant alterations in metabolites abundances involved in these pathways, support the genomic findings. Our study, integrating genomic and metabolomic data, demonstrates that long-term adaptation of microalgae to high CO 2 and/or warming can be characterized by a complex and dynamic genetic process and may advance our understanding of microalgae adaptation to global change., (© 2024 The Author(s). New Phytologist © 2024 New Phytologist Foundation.)

Wastewater treatment based on microalgae and bacteria symbiosis is an environmentally friendly, sustainable technology that has attracted attention recently because of its high efficiency in treating pollutants, saving energy, and short-term biomass recovery. Among them, the granular microalgae and bacteria combination emerges with the advantages of rapid gravity settling, good resistance to adverse environmental conditions, outstanding wastewater treatment performance, and easy biomass recovery. This review aims to clarify the microalgal-bacterial granule (MBG) - based process for wastewater treatment. In particular, MBG characteristics, granulation mechanism, and influence factors on the process are also discussed. The review contributes to the knowledge system related to MBG research in recent years, thereby pointing out research gaps that need to be filled in the future., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

As the concern for Ni contamination in the aquatic environment escalates, efforts for microalgal use in environmental monitoring and bioremediation are increasing. This study aims to evaluate the potential of Chlorella sorokiniana and Chlamydomonas reinhardtii for Ni bioremediation by investigating their physiological stress responses in Ni-contaminated environments. The analysis focuses on how Ni(II) uptake affects cell growth, nutrient metal homeostasis, and lipid unsaturation levels, as these parameters are critical indicators of metabolic stability and resilience essential for effective bioremediation. The microalgae were grown under mixotrophic conditions in a tris-acetate-phosphate (TAP) medium enriched with Ni(II), at concentrations (1-6 mg∙L -1 ) exceeding those typically found in wastewater, providing insights into metal stress under severe contamination conditions. Even though increased uptake of Ni(II) was observed for both algal species, accompanied by growth suppression at high Ni(II) concentrations, multi-elemental trace analysis revealed a significant, Ni concentration-dependent, uptake of growth media essential metals as well. Specifically, for both algal species, Zn uptake concentrations increased by approximately 20 times when going from control cultures, with no Ni(II) added, to cultures incubated with increasing Ni(II) concentrations. Overall, Zn uptake was determined to be approximately 3 orders of magnitude higher than Ni(II) uptake when high concentrations of Ni(II) were present, making Zn the metal with the most significant uptake. Similar uptake trends were observed for Cu and Co for both algal species, with Cu uptake being approximately 2 orders of magnitude higher, while Co remained below the Ni(II) concentrations at high added Ni(II) concentrations. For Chlorella sorokiniana, increased Fe uptake relative to Ni(II) uptake was observed (2 orders of magnitude higher), as was the case for Mn (1 order of magnitude higher). This induced increase in uptake of some of the growth media metals was attributed to their liberation from ethylenediaminetetraacetic acid (EDTA) in tris-acetate-phosphate (TAP) medium, following the addition of Ni(II), which has a higher stability constant (K f ) with EDTA and was added at concentrations comparable or higher than those of the other metals. Calculated levels of free Ni(II) and free metals in the medium matched the observed metal uptake trends as determined using multielemental inductively coupled plasma mass spectrometry. Negative ion electrospray mass spectrometry also revealed that EDTA-metal complexes in the TAP media decreased as Ni(II) concentrations increased. The lipid unsaturation level and relative ω-3 fatty acids concentration of both microalgal species, based on 1 H Nuclear Magnetic Resonance analysis, decreased with increasing Ni(II) concentration, with the decrease being more pronounced at Ni(II) incubation concentrations of 4 and 6 ppm. Unsaturation levels for individual lipid classes [monogalactosyldiacylglycerol (MGDG), digalactosyldiacylglycerol (DGDG), and sulfoquinovosyldiacylglycerol (SQDG)] in Chlamydomonas reinhardtii cells were also studied using positive ion mode electrospray mass spectrometry. At the highest Ni(II) concentrations, an overall reduction in unsaturation levels was observed for all 3 lipid classes, indicating a significant impact of elevated metal ion concentrations on membrane fluidity and therefore on cellular physiology and metabolism. Comparison of the two microalgal species under Ni-enriched conditions shows that Chlorella sorokiniana exhibits greater tolerance to the metal-induced stress under study than Chlamydomonas reinhardtii, suggesting its higher efficiency for the bioremediation in Ni-contaminated environments., Competing Interests: Declaration of Competing Interest The authors have no conflict of interest to declare., (Copyright © 2024 Elsevier GmbH. All rights reserved.)

The hormetic effects of antibiotics on Scenedesmus sp. werecompared with nitrogen limitationstrategies. We observed that 100 and 1000 nM supplementation with antibiotics could stimulate bothα-linolenic acid (ALA) and α-tocopherol productivities. Although nitrogen limitation had the best overall biomass and chlorophyll a productivity (∼ 43.83 % and 109.07 % ↑, respectively), tetracycline (1000 nM, T 1000 ) was the best antibiotic for biomass (∼ 12.08 % ↑) while erythromycin (100 nM, E 100 ) was the best for chlorophyll a (∼ 52.19 % ↑). The antibiotics also triggered accumulation of monounsaturated fatty acids, like C16:1 and C18:1, which the nitrogen stress strategies failed to achieve. Rifampicin (100 nM, R 100 ) and E 100 , with ∼3.92-4.14-fold increase in α-tocopherol and ∼4.41-4.81-fold increases in ALA productivities, reiterate the role of moderate stresses in stimulating high-value metabolites in microalgae. Our results provide an alternative medium engineering strategy for stimulating algal metabolites without compromising on the biomass. However, further studies are underwaytosafely remediate cultivation effluents and elucidate the physiological mechanisms of individual antibiotics to develop a more holistic strategy for targeted algal farming., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Biodegradation of microplastics (MPs) through microalgal strains would be of eco-friendly approach for significant pollution abatement. Polystyrene (PS) is a major contaminant in the marine environment; however studies on marine microalgal degradation of PS MPs have been very limited. In the present study, six marine microalgal strains viz. Picochlorum maculatum, Dunaliella salina, Amphora sp., Navicula sp., Synechocystis sp. and Limnospira indica were investigated for their ability to degrade PS MPs for the incubation period of 45 days. Results from weight reduction, ATR-FTIR, SEM, and molecular docking analysis confirmed that microalgae formed biofilms on PS MPs, causing structural changes, and laccase-driven enzymatic breakdown. A maximum weight loss of 23.2 ± 0.21% and a minimum of 11.3 ± 0.026% were caused by the colonized microalgae Synechocystis sp. and Amphora sp. respectively. The study indicated that a higher reduction rate was observed in the Synechocystis sp. Treated PS MPs with a rate of 0.0058 g/day and a lower half-life of 119.34 days. SEM analysis showed that microalgae caused pits, erosion, and damage to the PS film. ATR-FTIR confirmed the chemical modifications and proved biodegradation. Laccase enzyme activity was higher in Synechocystis sp., and molecular docking showed the laccase interaction with the derivatives of PS, elucidating the breakdown process. This study highlights the potential of microalgae for eco-friendly microplastic degradation and paves the way for future research on the by-products of this process. Exploring the ecological impact of by-products and optimizing scalable methods can further enhance the sustainability and practical applications of this promising solution., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Microalgae-based DeNOx technology, as an emerging approach for flue gas denitrification, is suitable for the deep treatment of NOx at medium to low concentrations. To address the ambiguity surrounding the removal pathways and mechanisms in the development of microalgae DeNOx technology, the pathways and mechanisms of NO removal within a microalgae cultivation system was investigated. By investigating the gas-liquid and liquid-solid nitrogen transfer pathways facilitated by algal cells, algal cells were found to play a pivotal role in NO removal by the T. obliquus PF3 cultivation system. Microalgae cells enhance NO transfer across gas-liquid phases via extracellular substance secretion, exogenous iron reduction, NO adsorption, and NO molecular absorption. During this process, NO is transformed in the liquid phase into molecular NO, ionic nitrate, and nitrite, as well as organically complexed NO. The soluble extracellular substances of T. obliquus PF3 are primarily composed of humic-like acids and fulvic-like acids, while bound extracellular substances are dominated by tryptophan and tryptophan-like proteins, both of which possess reductive properties conducive to iron reduction and NO adsorption/complexation. By employing ATP hydrolysis inhibitor HgCl 2 and analyzing nitrogen balance in the system, It was revealed that the primary NO removal pathway involves NO dissolution and oxidation within the algal culture broth, with ionic nitrogen being the predominant form assimilated and utilized by algal cells from the solution. This study clarifies the NO removal pathways and mechanisms within the microalgae cultivation system, thereby providing a theoretical foundation for the advancement and process design of microalgae-based DeNOx technology., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Background: In recent decades the demand for freshwater has drastically increased as a consequence of population growth, economic development, climate change and pollution. Therefore, any strategy for wastewater treatment can play a role in alleviating the pressure on freshwater sources., Results: In the present study an autochthonous microalgal pool (MP), isolated from a constructed wetland, was proposed as an alternative to the secondary treatment of an urban wastewater treatment system. The MP removal efficacy was compared to those obtained using Chlorella vulgaris and Scenedesmus quadricauda, against E. coli. Results exhibited a comparable removal efficacy and after 2 days, in samples inoculated with E. coli at lower density, S. quadricauda and C. vulgaris induced a decrease of 2.0 units Log and the autochthonous MP of 1.8 units Log, whereas in samples with E. coli at higher density the bacteria were reduced 2.8, 3.4 and 2.0 units Log by S. quadricauda, C. vulgaris and the autochthonous MP, respectively. Moreover, the identification of microalgal strains isolated from the MP revealed the presence of Klebsormidium sp. K39, C. vulgaris, Tetradesmus obliquus and S. quadricauda. Although the MP composition remained quite constant, at the end of the treatment, a different distribution among the microalgal species was observed with Klebsormidium sp. K39 found as dominant., Conclusion: The microalgal-based wastewater treatment appears as a valuable alternative, although further investigations, based on 'omics' approaches, could be applied to better explore any fluctuation within the MP species composition in an in situ trial. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., (© 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.)

Biokinetic models can optimise pollutant degradation and enhance microbial growth processes, aiding to protect ecosystem protection. Traditional biokinetic approaches (such as Monod, Haldane, etc.) can be challenging, as they require detailed knowledge of the organism's metabolism and the ability to solve numerous kinetic differential equations based on the principles of micro, molecular biology and biochemistry (first engineering principles) which can lead to discrepancies between predicted and actual degradation rates. More recently, data-driven machine-learning techniques have emerged as a promising alternative for modelling microbial systems. A few machine learning models (such as ANN, SVM, RF, DT, XG BOOST, etc.) have been used recently for modelling phenol degradation, but they lack the robustness of generating mathematical models. This gap is addressed in this study using Genetic Programming (GP) as the modelling approach for modelling the phenol degradation. This study utilises the microalgae Acutodesmus Obliquus , finding that phenol degradation of 98% required 216 hours. Both the traditional kinetic approach and the Genetic Programming (GP) approach were used to determine the specific growth rate ( µ max ) and saturation constant ( K s ). It is noted that without any a priori information on the form of the mathematical mode, GP can evolve a model which closely fits the Monod kinetics, thus demonstrating that data-driven models can bring out the first engineering principles on which biokinetic models are dependent or framed in a most swift and effective way. Performance was assessed using root mean square error (RMSE) and correlation coefficient ( R ), with the GP model showing superior predictive accuracy.

Optimizing photosynthesis in microalgae is crucial for enhancing bioenergy production and addressing global energy demands. Here, the diatom-derived carbon dots (d-CDs) were synthesized through a hydrothermal method and explored their impact on the growth and photosynthesis of Chlorella. The results demonstrated that d-CDs significantly improved Chlorella growth, with a 59.4% increase in biomass, a 35.3% increase in proteins and a 118.9% increase in carbohydrates. The d-CDs penetrated the cells and interacted with chloroplasts, accelerating photosynthetic electron transfer during light-dependent reactions. This led to a 26.3% increase in ATP and a 55.5% increase in NADPH production. Transcriptomic analysis revealed that d-CDs upregulated ribosome-related genes and stimulated the expression of genes encoding nitrite reductase and glutamine synthetase, thereby enhancing nitrogen assimilation and utilization. This study highlights the potential of CDs derived from biomass in promoting Chlorella growth and enhancing photosynthesis, offering a promising approach for sustainable bioresource development., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025. Published by Elsevier Ltd.)

Aquatic biomass, particularly microalgae and duckweed, presents a promising and sustainable alternative source of plant-based protein and bioactive compounds for food and feed applications. This review highlights the nutritional potential of these aquatic species, focusing on their high protein content, rapid growth rates, and adaptability to nonarable environments. Microalgae, such as Chlorella and Arthrospira spp., and duckweed, such as Lemna minor , are evaluated for their functional food applications, including their roles as protein supplements, bioactive components, antioxidants, and emulsifiers in food formulations. The study also examines their environmental benefits, including wastewater bioremediation, nutrient recycling, and greenhouse gas mitigation, which contribute to a more sustainable agricultural system. Technological advancements in the cultivation, harvesting, and processing of microalgae and duckweed are discussed to enhance their scalability and economic feasibility in food and feed production. The findings suggest that integrating microalgae and duckweed into agricultural and food systems can significantly improve food security, nutritional outcomes, and sustainability. Future research should focus on optimizing cultivation efficiencies, advancing protein extraction techniques, and expanding the applications of aquatic biomass in various food products.

Microalgal cultivation is increasingly important for industrial, agricultural, and environmental monitoring. Current methodologies for monitoring microalgal growth require periodical sampling, bulky laboratory equipment and specialized personnel. A novel 'dip-stick' micro-cultivation methodology based on fluorinated ethylene propylene microcapillary strips is herein proposed for real-time detection of microalgal growth. Cultivation of the microalgae Parachlorella kessleri in microcapillary strips, with no replacement of growing media nor physical aeration, matched the growth rate µ observed for a sparged Erlenmeyer (µ=0.37 /day) representing a > 3-fold improvement compared to an unsparged Erlenmeyer (µ=0.12 /day). Growth modelling of P. kessleri in the microcapillary strips established light intensity as a limiting growth factor. The transparency of the microcapillary strips enabled accurate and non-invasive determination of single-cell morphology and cell cycle events, which have been benchmarked against high-resolution flow cytometry. The microanalytical solution herein presented could offer a new bioanalytical solution for in-situ water management and high-throughput microalgal productivity assessment., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Paulo R.F. Rocha reports financial support was provided by European Research Council. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025. Published by Elsevier Ltd.)

Duckweed has been highlighted as an appropriate biomass for low-carbon industries because of its significantly high production rate and multiple resource value. However, the outbreak of microalgae is a practical issue that decreases duckweed production yield. This study demonstrated that the growth of the duckweed Lemna aequinoctialis from factory wastewater was enhanced by colonization with indigenous plant growth-promoting bacteria (PGPB), whereas the growth of a duckweed competitor microalga, Coelastrella sp. KC10, from the same wastewater was reduced by indigenous microalgal growth-inhibiting bacteria (MGIB). Finally, a quadruple co-culture of a synthetic duckweed holobiont, L. aequinoctialis colonized by both KLaR20 (PGPB) and KLaR16 (MGIB), and Coelastrella sp. KC10 successfully recovered the duckweed production level by 117.5% in frond number and 84.5% in dry weight in the absence of microalgae. This case study demonstrates for the first time that duckweed holobionts can be reconstructed and enforced to antagonize growth competitor microalgae., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025. Published by Elsevier Ltd.)

Background: The gradual extrusion of water-soluble intracellular components (such as proteins) from microalgae after pulsed electric field (PEF) treatment is a well-documented phenomenon. This could be utilized in biorefinery applications with lipid extraction taking place after such an 'incubation' period, i.e., a post-PEF-treatment step during which the biomass is left undisturbed before any further processing. The goal of this work was to further explore how this incubation could improve lipid extraction., Results: Experiments were conducted on wet, freshly harvested Auxenochlorella protothecoides, treated with 0.25 or 1.5 MJ/kg DW and incubated for 24 h. Lipid extraction took place with a monophasic ethanol:hexane:water, 1:0.41:0.04 vol/vol/vol mixture with a 75.6 mL solvent per 1 g of dry biomass ratio. The kinetics of the extraction were studied with samples taken between 10 and 1080 min from fresh and incubated biomass. The yields at 10 min were significantly increased with incubation compared to without (31.2% dry weight compared to 1.81%, respectively). The experimental data were fitted with the Patricelli model where extraction occurs in two steps, a rapid washing of immediate available lipids and a slower diffusion one. During Nile-Red staining of microalgae and microscopy imaging, a shift of emission from both GFP and RFP channels to mostly RFP was observed indicating an increase in the polarity of the environment of Nile-Red. These led to an adaption of a biphasic ethanol:hexane:water 1:6:0.4 vol/vol/vol solvent with 37 mL solvent per 1 g of dry biomass ratio which while ineffective on fresh biomass, achieved a 27% dry weight yield from incubated microalgae. The extraction efficiency in the biphasic route was lower compared to the monophasic (i.e., 69% and 95%, respectively). It was compensated however, by the significant solvent reduction (37 mL to 75.6 mL respectively), in particular the ethanol minimization. For the extraction of 1 L lipids, it was estimated that the energy consumption ratio for the biphasic process was 1.6 compared to 9.9 for monophasic, making clearly the most preferential one., Conclusions: This biphasic approach significantly reduces solvent consumption and the respective energy requirement for solvent recovery. Incubation thus could majorly improve the commercialization prospects of the process., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

This study reports on the influence of lactic acid fermentation on the proteomic and peptidomic profiles of spirulina protein isolate (SPI)-fortified, freeze-dried powders containing living Lacticaseibacillus rhamnosus GG (LGG) cells during in vitro digestion. For comparison, powders fortified with whey protein isolate (WPI) and pea protein isolate (PPI) were also evaluated. Prior to freeze-drying, the powder precursors were either non-treated or fermented. Capillary SDS-PAGE electropherograms revealed a mild proteolytic effect due to fermentation. C-phycocyanin (SPI) and β-lactoglobulin (WPI) showed the highest resistance to pepsinolysis. All samples were responsive to pancreases, with fermented WPI showing the lowest responsiveness. Fermentation enhanced the degree of hydrolysis (DH) in gastric chymes, whereas in intestinal chymes, DH followed the order SPI > PPI > WPI, with fermentation showing no significant impact. A total of 6, 11, and 52 potential bioactive peptide sequences, associated with various beneficial activities, were identified in the SPI, PPI, and WPI digesta, respectively. The highest amino acid bioaccessibilities were observed for cysteine and methionine in SPI, isoleucine and arginine in PPI, and glycine in WPI. In conclusion, fortifying probiotic formulations with protein isolates offers secondary health benefits, stemming from the release of bioactive peptides and bioaccessible essential amino acids., Competing Interests: Declaration of competing interest PM International AG had no influence on the study design, data collection and analysis, decision to publish, or preparation of the manuscript. LIST affiliated authors declare that the research was conducted in the absence of any financial relationships that could be construed as a potential conflict of interest., (Copyright © 2025. Published by Elsevier B.V.)

Astaxanthin (ASX), "king of carotenoids", is a xanthophyll carotenoid that is characterized by a distinct reddish-orange hue, procured from diverse sources including plants, microalgae, fungi, yeast, and lichens. It exhibits potent antioxidant and anti-ageing properties and has been demonstrated to mitigate ultraviolet-induced cellular and DNA damage, enhance immune system function, and improve cardiovascular diseases. Despite its broad utilization across nutraceutical, cosmetic, aquaculture, and pharmaceutical sectors, the large-scale production and application of ASX are constrained by the limited availability of natural sources, low production yields and stringent production requirements. This review provides a comprehensive analysis of ASX applications, emphasizing its dual roles in cosmetic and nutraceutical fields. It integrates insights into the qualitative differences of ASX from various natural sources and assesses biosynthetic pathways across organisms. Advanced biotechnological strategies for industrial-scale production are explored alongside innovative delivery systems, such as emulsions, films, microcapsules, nanoliposomes, and nanoparticles, designed to enhance ASX's bioavailability and functional efficacy. By unifying perspectives on its nutraceutical and cosmetic applications, this review highlights the challenges and advancements in formulation and commercialization. Prospective research directions for optimizing ASX's production and applications are also discussed, providing a roadmap for its future development., Competing Interests: Declarations. Conflict of interest: The authors declare no competing interests., (© 2025. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Microalgal exopolysaccharides (EPS) possess significant functional benefits across various industrial sectors, but their commercial feasibility is constrained by inefficient synthesis and poorly understood synthesis mechanisms. This study found that 1.25 mmol/L sodium bisulfite promoted EPS accumulation to 224.78 mg/L by Auxenochlorella protothecoides. Inhibiting endogenous H 2 O 2 blocked the sodium bisulfite-induced increase in EPS content and reversed the upregulation of EPS biosynthesis-related genes, underscoring the involvement of H 2 O 2 signaling in microalgal EPS accumulation. Furthermore, omics analyses revealed a reconfiguration of metabolites in carbohydrates, proteins, and lipids, facilitating the reallocation of carbon flux. Specifically, sodium bisulfite reduced protein storage while enhancing carbohydrate anabolism for EPS precursors, redirecting carbon towards EPS accumulation. This process acted as a defense against oxidative stress, aided by increased lipid and starch production. Collectively, the findings boosted microalgal EPS production and elucidated the mechanisms involving cellular H 2 O 2 signaling and carbon redistribution, providing theoretical support for large-scale microalgal EPS production., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier Ltd. All rights reserved.)

Ciprofloxacin (CIP) and oxytetracycline (OTC) are commonly detected antibiotic species in breeding wastewater, and microalgae-based antibiotic treatment technology is an environmentally friendly and cost-effective method for its removal. This study evaluated the effects of CIP and OTC on Scenedesmus sp. in the breeding wastewater tailwater and the removal mechanisms of antibiotics. The results showed that Scenedesmus sp could increase antibiotic tolerance by enhancing antioxidant system activity. Compared to CIP, Scenedesmus sp showed better performance for OTC removal, the removal efficiencies were 100%, 96.87%, 95.75%, 90.18% and 83.91% at 0.1, 0.5, 1, 5, and 10 mg L - 1 OTC, respectively. The removal routes indicated that CIP was mainly removed by biodegradation (38.88%) and photolysis (14.30%) whereas OTC was mainly removed by hydrolysis (43.47%) and biodegradation (33.45%). Product toxicity predictions showed that most of the degradation products of CIP and OTC were less toxic than their parent compounds, confirming the feasibility of microalgae biotreatment for antibiotic removal., Competing Interests: Declarations. Conflict of Interest: The authors declared no conflicts of interest., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

With the rapid development of synthetic biology, genetic engineering, and molecular manipulation methods in recent years, microalgae, as representatives of microbial cell factories, have been widely used as hosts in the production of high-value bioproducts, such as oils, pigments, proteins, and biofuels, demonstrating promising prospects of application in biochemical energy, food and drugs, and environmental protection. Despite these advancements, the low production efficiency of microalgae limits their industrial application. In addition to strain improvement and culture condition optimization, the regulation by exogenous chemical additives serves as a promising optimization strategy. This method relies on straightforward phenotypic screening and circumvents the necessity for intricate understanding of molecular targets in the metabolic and catabolic pathways involved in the synthesis of bioproducts. It enables rapid yield increasing of high-value bioproducts from microalgae and obtaining the required phenotypes. Although studies have reported the use of alternatives means such as exogenous additives to improve the growth of microalgae and the yield of high-value bioproducts, the classification and summarization of the types, applications, targeted strains, and molecular mechanisms of these additives are not comprehensive. Here, we review the studies using chemical inducers or enhancers to improve cell growth and high-value bioproduct accumulation in microalgae in recent years. This paper focuses on the types of exogenous additives, the effects of exogenous additives and their combinations on microalgae growth and high-value bioproduct accumulation, and the molecular mechanisms of related effects. We aim to provide information for researchers to use methods of synthetic biology to develop suitable cell chassis and harness microalgae for industrial production.

This paper aims to test several modeling approaches for predicting toxicity of binary mixtures with potential synergy and antagonism. The approach based on the construction of isoboles was first tested and criticized. In contrast to conventional approaches, and in order to be mathematically consistent with the additivity assumptions, non-linear isoboles have been constructed. This approach was compared with that proposed by Minto et al. (2000), which measures deviations from additivity by considering standardized variables and which considers the entire Hill concentration-response curves. The selected models were tested on a case study related to chlorine-based disinfectant by-products (DBPs), using experimental data describing the effect of five DBPs (monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, bromochloroacetic acid and 1,1-dichloropropan-2-one) on a unicellular green algae Raphidocelis subcapitata. The approach based on the construction of isoboles has shown its limitations. Indeed, in cases where the individual substances involved have different slopes in terms of their Hill concentration-effect relationships, the so-called zone of indetermination can be large. Furthermore, conclusions drawn from isoboles based on EC 50 s or EC 20 s may not be consistent. Minto's approach makes it possible to construct interaction indicators that consider the entire Hill concentration-response curve. Response surfaces can be constructed to visualize the areas of concentration of the two substances involved that maximize the interaction effects., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 The Authors. Published by Elsevier B.V. All rights reserved.)

This study investigates the photoinduction techniques for the maximization of astaxanthin production in Chromochloris zofingiensis following heterotrophic growth. Leveraging blue light, this study enhanced carbon allocation by suppressing the tricarboxylic acid cycle and activating the methylerythritol phosphate and pentose phosphate pathways to facilitate astaxanthin accumulation. Under blue light, an astaxanthin content of 5.14 ± 0.40 mg g -1 was achieved in flasks for 5 day, while in larger 3-L plate photobioreactors, the content was 5.76 ± 0.55 mg g -1 in only 3 days by the increased light intensity and diluted biomass concentration. Moreover, higher astaxanthin level of 6.26 ± 0.53 mg g -1 in peaks at 36 h was also realized by exogenous inducer (gibberellin A 3 , 2 mg L -1 and H 2 O 2 , 5 mL L -1 ) with productivity of 39 mg L -1 d -1 . These outcomes are promising for scaling up sustainable astaxanthin production with useful commercial applications in the pharmaceuticals, cosmetics, and nutraceutical industries., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier Ltd. All rights reserved.)

Azo dyes constitute 60-70% of commercially used dyes and are complex, carcinogenic, and mutagenic pollutants that negatively impact soil composition, water bodies, flora, and fauna. Conventional azo dye degradation techniques have drawbacks such as high production and maintenance costs, use of hazardous chemicals, membrane clogging, and sludge generation. Constructed Wetland-Microbial Fuel Cells (CW-MFCs) offer a promising sustainable approach for the bio-electrodegradation of azo dyes from textile wastewater. CW-MFCs harness the phytodegradation capabilities of wetland plants like Azolla, water hyacinth, and Ipomoea, along with microalgae such as Nostoc, Oscillatoria, Chlorella, and Anabaena, to break down azo dyes into aromatic amines. These intermediates are then reduced to CO2 and H2O by microalgae in the fuel cells, while simultaneously generating electricity. CW-MFCs offer advantages including low cost, sustainability, and use of renewable energy. The valorization of the resulting algal and plant biomass further enhances the sustainability of this approach, as it can be used for biofuel production, nutraceuticals, pharmaceuticals, and bio-composting. Implementing CW-MFCs as a tertiary treatment step in textile industries aligns with the circular economy concept and contributes to achieving several Sustainable Development Goals (SDGs)., (© The Author(s) 2025. Published by Oxford University Press on behalf of Applied Microbiology International.)

Extracellular polymeric substances (EPS) can effectively attenuate heavy metal mobility in aquatic ecosystems and reduce metal toxicity to cells. However, a systematic study of microalgae EPS responses and their adsorption behaviors, characteristics, and mechanisms under different heavy metal exposures has not been performed. In this study, EPS extracted from Chlamydomonas reinhardtii CC-125 was analyzed for compositional changes (monosaccharides and proteins) under Cd, Cu, Pb, and Zn treatments. The EPS adsorption capacities and mechanisms for the four metal ions were also investigated. Cd (10 mg/L), Cu (5 mg/L), and Zn (5 mg/L) exposure induced changes in the microalgal EPS composition and structure, and a protein/polysaccharide ratio of greater than 1 was found. This result indicated the crucial role of proteins in stress resistance. In contrast, Pb stress resulted in an increase of 532.64% and 117.48% in proteins and polysaccharides, respectively, with galactose and glucose playing key roles in this process. A fluorescence analysis revealed that Cd/Pb exposure reduced the tryptophan and tyrosine levels in the EPS, while Cu/Zn only weakened tryptophan. As a biosorbent, the adsorption capacity of the EPS for the four metals followed the order of Pb > Cd > Cu > Zn. The fluorescence quenching titration results revealed that fluorescent compounds in the EPS had the strongest complexation ability with Pb (logK SV : 8.16 × 10 3 ), followed by Cu (logK SV : 1.79 × 10 3 ), while their abilities for Cd and Zn were weaker. A spectroscopic analysis indicated that the primary functional groups involved in EPS binding with Pb/Cd and Cd/Zn were protein carboxyl groups (C=O/O-C=O) and glycosidic bonds (C-OH/C-O-C), respectively. This study elucidates the response strategies and adsorption mechanisms of the C. reinhardtii EPS to different metals and provides a basis for environmental heavy metal pollution bioremediation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier Ltd. All rights reserved.)

Calcium (Ca 2+ )-dependent signalling plays a well-characterised role in the perception and response mechanisms to environmental stimuli in plant cells. In the context of a constantly changing environment, it is fundamental to understand how crop yield and microalgal biomass productivity are affected by external factors. Ca 2+ signalling is known to be important in different physiological processes in microalgae but many of these signal transduction pathways still need to be characterised. Here, compartment-specific Ca 2+ dynamics were monitored in Chlamydomonas reinhardtii cells in response to environmental stressors, such as nutrient availability, osmotic stress, temperature fluctuations and carbon sensing. An in vivo single-cell imaging approach was adopted to directly visualise changes of Ca2+ concentrations at the level of specific subcellular compartments, using C. reinhardtii lines expressing a genetically encoded ratiometric Ca 2+ indicator. Hyper-osmotic shock caused cytosolic and chloroplast Ca 2+ elevations, whereas high temperature and inorganic carbon availability primarily induced Ca 2+ transients in the chloroplast. In contrast, hypo-osmotic stress only induced Ca 2+ elevations in the cytosol. The results herein reported show that in Chlamydomonas cells compartment-specific Ca 2+ transients are closely related to specific external environmental stimuli, providing useful guidance for studying signal transduction mechanisms exploited by microalgae to respond to specific natural conditions., (© 2025 The Author(s). Plant, Cell & Environment published by John Wiley & Sons Ltd.)

The present study evaluates for the first time the seasonal performance of an innovative green groundwater treatment. The pilot plant combines microalgae-bacteria treatment and a cork-wood biofilter to reduce nitrates, pesticides, antibiotics (ABs), and antibiotic resistance genes (ARGs) from groundwater. Groundwater had nitrate concentrations ranging from 220 to 410 mg/L, while ABs (sulfonamides and fluoroquinolones) and pesticides (triazines) were detected at concentrations ranging from a few ng/L to 150 ng/L. Only the gene targets sul1, tetM and the class 1 integron-integrase gene (intl1) were detected in the groundwater. The microalgae-biofilter treatment system effectively removed 15%-98% of nitrates, depending on the season, and consistently eliminated over 90% of ABs and pesticides year-round. Among the components of the treatment system, the microalgal system was the most effective at removing ABs and pesticides. However, the cork-wood biofilter showed superior performance in reducing the bacterial load in groundwater, achieving more than a 1-log reduction in the absolute abundance of genes such as sul1 and intl1. The accumulation of ABs and pesticides in microalgae biomass was minimal or undetectable (<20 ng/g of fresh weight). Overall, our results indicate that the microalgae-biofilter treatment plant is an effective solution for significantly reducing nitrates, antibiotics, and pesticides from groundwaters, while also producing a valuable biomass, and meeting drinking water standards during warmer months., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Victor Matamoros reports financial support was provided by European Union. Jessica Subirats Medina reports financial support was provided by Government of Catalonia Agency for Administration of University and Research Grants. Marc Vina reports financial support was provided by Government of Catalonia. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025. Published by Elsevier Ltd.)

Dynamic therapies such as photodynamic therapy (PDT) and sonodynamic therapy (SDT) have potential in cancer treatment. Microalgae have attracted increasing attention because of their high active mobility, flexibility in terms of functionality, and good biocompatibility. In this study, surface-engineered microalgae Chlorella vulgaris (Chl) modified with metal‒organic framework (MOF) nanoparticles (denoted Chl-MOF) are successfully developed for synergistic photo-sonodynamic therapy and immunotherapy. The resulting Chl-MOF can be used as an oxygenator for O 2 generation through Chl-mediated photosynthesis, alleviating tumor hypoxia. Furthermore, Chl-MOF produces reactive oxygen species (ROS) during laser and ultrasound (US) irradiation, further augmenting the photo-sonodynamic effects and enhancing tumor cell apoptosis. Owing to the high mobility of Chl, cellular uptake efficiency and accumulation in deep tumor sites are 5.2-fold and 3.3-fold higher, respectively, for Chl-MOF than for the MOF. Owing to the immunomodulatory effects of Chl, Chl-MOF can increase natural killer (NK) cell cytotoxic activity, increase dendritic cell (DC) antigen-presenting ability, reverse the establishment of an immunosuppressive tumor microenvironment (TME), and induce a relatively strong antitumor immune response. Chl-MOF can effectively reduce breast cancer size by 88.8 % in vitro and in vivo via synergistic photo-sonodynamic therapy and immunotherapy. These intriguing properties of the combination of Chl and MOF provide promising platform for cancer theranostic applications. STATEMENT OF SIGNIFICANCE: : • Chl acts as an O 2 generator for alleviating hypoxia in tumors. • The high mobility of Chl resulted in 3.3-folds higher tumor accumulation. • The Chl-MOF can induce synergistic photo-sonodynamic effects and a relatively strong antitumor immune response. • Chl-MOF effectively reduce breast cancer size by 88.8 % via synergistic therapies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

The chemical looping co-gasification of nitrogen-containing algal biomass and coal could effectively realize the high-value utilization of gasification products, but the mechanism of conversion of nitrogen-containing pollutants is not clear. In this work, the effects of the different ratios of microalgae on the co-gasification process were first explored, and the results showed that the 40 % coal + 60 % microalgae blending had the best synergistic effect, with a comprehensive synergistic index (CSI) of 1.35 as the maximum value. The effects of temperature, the ratio of OCs to feed (O/C) and steam flow rate on the evolution of nitrogen-containing species in the co-gasification products were explored based on the optimal mixing ratio, and the results showed that elevating the reaction temperature promotes the generation of nitrogen oxide precursors, and an appropriate amount of steam could inhibit the generation of NOx. The nitrogen in coke mainly came from the Maillard reaction between carbonyl (-CO) compounds and amino (-NH 2 ) compounds and its main forms are pyridine nitrogen (N-5) and pyrrole nitrogen (N-6). Based on the nitrogen accumulation forms in the products of each phase, the mechanism of nitrogen transport and conversion in the chemical looping co-gasification of coal and microalgae (CM-CLCG) process was proposed. This study provides a reference for the synergistic utilization of coal and biomass and the control process of nitrogen-containing pollutants., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier B.V. All rights reserved.)

Dye-contaminated wastewater poses serious environmental risks to ecosystems and human health. Diatoms, algae with nanoporous frustules (cell walls), offer promising potential for wastewater remediation due to their high surface area and adsorption properties. While dead diatom biomass is well-studied for biosorption, research on living diatoms' bioaccumulation and biotransformation potential is limited, with gaps in kinetic and equilibrium modeling of dye adsorption. Here, we analyzed the adsorption of crystal violet (CV) dye onto living Phaeodactylum tricornutum (P-cell) and Navicula cryptocephala var. veneta (N-cell) diatoms by characterizing the physiochemical properties of the species' outer surfaces and monitoring the adsorption of CV using surface-specific second harmonic scattering (SHS) spectroscopy. Direct monitoring of dye adsorption, rather than its removal from the solution, enables a more accurate investigation of adsorption kinetics and thermodynamics, revealing strong correlations with the cell surface structure and composition. We found that the N-cell has a greater adsorption capacity for CV than the P-cell, though with slightly less favorable adsorption free energy. Ionic strength could impact uptake capacities, likely due to competition between metal cations and the dye cation as well as surface screening. SHS experiments revealed a simple adsorption process for N-cells, while P-cells exhibited a multistep process involving CV transport through thinner, nonporous cell walls to the plasmic membrane, contributing to favorable adsorption free energy. The thicker, porous walls of N-cells provided more surface sites, increasing the capacity, while P-cells facilitated deeper uptake. Ionic strength had only a significant effect on adsorption capacity, not adsorption free energy, reflecting the intricacies that govern adsorption and uptake by living organisms. The comprehensive analysis presented herein demonstrates great potential for diatoms to be used as biosorbents in dye remediation and provides systematic relationships between the structure and function of diatom cell walls, which will inform the use of tailored species for more efficient remediation.

Alkaline environments such as alkaline lands, lakes, and industrial wastewater are not conducive to the growth of plants and microorganisms due to high pH and salinity. ChbZIP1 is a bZIP family transcription factor isolated from an alkaliphilic microalgae ( Chlorella sp. BLD). Previous studies have demonstrated its ability to enhance alkaline tolerance in Arabidopsis thaliana . However, the potential of ChbZIP1 to confer similar alkaline tolerance in other microalgae remains unclear, and the specific mechanisms are not fully understood. The analysis of cellular physiological and biochemical indicators revealed that the ChbZIP1 transformants exhibited enhanced photosynthetic activity, increased lipid accumulation, and reduced fatty acid unsaturation. Genes associated with cellular reactive oxygen species (ROS) detoxification were found to be upregulated, and a corresponding increase in antioxidant enzyme activity was detected. In addition, the relative abundance of intracellular ROS and malondialdehyde (MDA) was significantly lower in the transformants. In summary, our research indicates that ChbZIP1 enhances the tolerance of Chlamydomonas reinhardtii to alkaline environments through several mechanisms, including the repair of damaged photosynthesis, increased lipid accumulation, improved fatty acid unsaturation, and enhanced antioxidant enzyme activity. This study aims to contribute to a more comprehensive understanding of the mechanisms underlying alkalinity tolerance in microalgae and offers new insights and theoretical foundations for the utilization of microalgae in alkaline environments.

Microalgae's adaptability and resilience to Earth's diverse environments have evolved these photosynthetic microorganisms into a biotechnological source of industrially relevant physiological functions and biometabolites. Despite this, microalgae-based industries only exploit a handful of species. This lack of biodiversity hinders the expansion of the microalgal industry. Microalgal bioprospecting, searching for novel biological algal resources with new properties, remains a low throughput and time-consuming endeavour due to inefficient workflows that rely on non-selective sampling, monoalgal culture status and outdated, non-standardized characterization techniques. This review will highlight the importance of microalgal bioprospecting and critically explore commonly employed methodologies. We will also explore current advances driving the next generation of smart algal bioprospecting focusing on novel workflows and transdisciplinary methodologies with the potential to enable high-throughput microalgal biodiscoveries. Images adapted from (Addicted04 in Wikipedia File: Australia on the globe (Australia centered).svg. 2014.; Jin et al. in ACS Appl Bio Mater 4:5080-5089, 2021; Kim et al. in Microchim Acta 189:88, 2022; Tony et al. in Lab on a Chip 15, 19:3810-3810; Thermo Fisher Scientific INC. in CTS Rotea Brochure)., Competing Interests: Declarations. Competing interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2025. The Author(s).)

1. This review was conducted to examine the nutritional composition of microalgae and their effects as a feed ingredient in poultry diets, delving into their influence on the production and quality of meat and eggs. Data collection focused on peer-reviewed scientific articles, with no limitation on the temporal horizon.2. Regarding nutritional composition, the collected papers indicated that certain microalgae species have a rich nutritional composition, with approximately 50% of their biomass composed of proteins. They contain a high concentration of EPA and DHA, important fatty acids that are found in low concentrations in conventional feedstuffs, and the presence of carotenoids such as beta-carotene.3. Incorporating microalgae into the diet of poultry can improve performance variables, such as mortality, live weight and feed conversion rate. It promotes benefits in meat and egg quality, with reduced cholesterol, increased EPA and DHA, intensified colour and higher concentration of carotenoids.

We investigated whether microalgae or linseed supply during the early postpartum period affects ovarian restimulation and supports the first postpartum ovulation in lactating anovulatory goats. Thirty-eight An-glo-Nubian-crossbred adult goats were allocated into three groups, one with a control diet ( n = 12), fed a total mixed ration (TMR) comprising chopped elephant grass and concentrate; an algal diet ( n = 13), fed TMR + green microalgae (1% dry matter); and a linseed diet ( n = 13), TMR + linseed (12% dry matter). Supplements were furnished from the second to fifth week (time of weaning). Goats were estrus synchronized on day 40 by insertion of an intravaginal CIDR device for 5 days, after which 0.075 mg PGF2α was applied to induce ovulation, and estrus was monitored for 72 h. From the 5th-15th day of ovulation induction, the corpus luteum (CL) area and progesterone rate were monitored. The algal and linseed groups showed lower feed intake ( p < 0.001) and higher ( p < 0.001) triglyceride levels/follicle numbers, respectively. After estrus induction, no differences were observed in estrus response; however, the linseed group showed more and larger growing follicles ( p = 0.016 and p < 0.01), a higher ovulation rate ( p < 0.05), a larger CL area ( p < 0.05), and higher progesterone levels ( p < 0.001). Linseed after delivery stimulates follicular growth before and after ovulation induction, favoring better CL quality during the first ovulation.

Integrating microalgae into wound dressings has proven effective in promoting chronic wound healing through photosynthesis-induced oxygen release. However, challenges such as high crosslinking temperatures and prolonged gel molding processes limit microalgae growth and reduce the overall therapeutic impact. In this work, inspired by cell-symbiotic photo-crosslinked hydrogels, we present a novel photo-crosslinked microalgae carboxymethyl chitosan composite hydrogel. This hydrogel completes crosslinking at room temperature within 30 s, enhancing chronic wound healing. The composite gel incorporates photosynthesizing unicellular microalgae (Chlamydomonas reinhardtii) and the antimicrobial agent ciprofloxacin during preparation. In light, the gel continues to photosynthesize, releasing oxygen while simultaneously acting as an antibacterial agent. This dual action results in the upregulation of CD31 and VEGFA levels and the downregulation of HIF-1α levels in diabetic wounds. The wound closure rate reached approximately 96.70 % on day 12 in the composite gel group, compared to only 78.98 % in the control group. Therefore, the composite gel promotes healing by reducing local hypoxia, encouraging angiogenesis, and lowering infection risk. These results suggest that photo-crosslinked microalgae composite gels provide an effective strategy for localized oxygen delivery to promote wound healing and offer a viable method for rapidly preparing living biomaterials under suitable conditions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Limited knowledge of fucoxanthin's changes during digestion necessitates comprehensive investigation to ensure its efficacy as a functional ingredient. This study assessed the effects of digestion on fucoxanthin's bioaccessibility, antioxidant activity, colour changes, and metabolite formation through in vitro gastrointestinal digestion. Results indicated the highest bioaccessibility during gastric digestion (0.03 ± 0.00 mg/mL), followed by intestinal and mouth with 0.012 ± 0.00 and 0.011 ± 0.13 mg/mL, respectively. Antioxidant activity was the highest at the gastric stage, with significant activity persisting post-digestion (P < 0.05). Colour changes were significant, with total colour differences (∆E*) of 2.40, 2.86, and 2.76 at the mouth, gastric, and intestinal stages, respectively. LC-MS/MS-based metabolomics analysis revealed 15 key metabolites, with carboxylic acids as major metabolites during gastric and intestinal stages. Pearson correlation analysis demonstrated a significant correlation between identified metabolites with bioaccessibility, antioxidant activity, and colour changes, underscoring fucoxanthin's potential as a promising functional food ingredient., Competing Interests: Declaration of competing interest The authors report no commercial or proprietary interest in any product or concept discussed in this article., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Cultivating microalgae for the remediation of aquaculture wastewater provides a promising solution for pollution control. However, the economic viability of this approach faces challenges due to the high costs associated with microalgal biomass harvesting. This study aims to address this issue by immobilizing microalgae onto coral velvet carriers, enhancing the efficiency of biomass recovery. Four types of microalgae were screened: Chlorella sp., Isochrysis galbana, Chaetoceros sp., and Nannochloropsis sp. Among them, Isochrysis galbana exhibited the best self sedimentation rate, achieving a self sedimentation rate of 94.36%. Chlorella sp. demonstrated the best denitrification rate, with a nitrate removal rate of 100% and an inorganic nitrogen removal rate of 79.13%. In addition, this study found that extracellular polymeric substances(EPS) affects the self-settling performance of microalgae, and the results emphasize the key role of tightly-bound EPS(TB-EPS) content in determining self settling efficiency. Furthermore,the assessments of the purification of simulated aquaculture wastewater were conducted, comparing the outcomes of co-cultivation with mono-culture. The co-cultivation strategy showed exceptional efficacy, achieving a 100% removal rate for NO 3 - -N by the 5th day. In contrast, mono-cultures of Chlorella sp. and Isochrysis galbana showed removal rates of 77.76% and 45.72%, respectively, at the same interval. Applying of the co-cultivation microalgal biofilm to treat the actual aquaculture wastewater showed remarkable denitrification performance, attaining a 100% removal rate for NO 3 - -N by the 7th day. The study proposes the co-cultivation of Chlorella sp. and Isochrysis galbana for treating aquaculture wastewater and explores the potential application of immobilization technology to remove nitrogen-containing pollutants., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

The impact of the world's growing population on food systems and the role of dietary patterns in the management of non-communicable diseases underscore the need to explore sustainable and dietary protein sources. Although microalgae have stood out as alternative sources of proteins and bioactive peptides, some species such as Nannochloropsis gaditana remain unexplored. This study aimed to characterize N. gaditana 's proteome and evaluate its potential as a source of bioactive peptides by using an in silico approach. A total of 1955 proteins were identified and classified into functional groups of cellular components, molecular functions, and biological processes. In silico gastrointestinal digestion of identified proteins demonstrated that 202 hydrophobic and low-molecular-size peptides with potential bioactivity were released. Among them, 27 exhibited theorical antioxidant, antihypertensive, antidiabetic, anti-inflammatory, and/or antimicrobial activities. Seven of twenty-seven peptides showed ≥20% intestinal absorption, suggesting potential systemic effects, while the rest could act at local level. Molecular docking demonstrated strong affinities with key enzymes such as MPO, ACE, and DPPIV. Resistance to the digestion, capacity to be absorbed, and multifunctionality were demonstrated for peptide FIPGL. This study highlights N. gaditana 's potential as a sustainable source of novel potential bioactive peptides with promising local and systemic biological effects.

Extensive anthropogenic activity has led to the accumulation of organic and inorganic contaminants in diverse ecosystems, which presents significant challenges for the environment and its inhabitants. Utilizing microalgae as a bioremediation tool can present a potential solution to these challenges. Microalgae have gained significant attention as a promising biotechnological solution for detoxifying environmental pollutants. This is due to their advantages, such as rapid growth rate, cost-effectiveness, high oil-rich biomass production, and ease of implementation. Moreover, microalgae-based remediation is more environmentally sustainable for not generating additional waste sludge, capturing atmospheric CO 2 , and being efficient for nutrient recycling and sustainable algal biomass production for biofuels and high-value-added products generation. Hence, microalgae can achieve sustainability's three main pillars (environmental, economic, and social). Microalgal biomass can mediate contaminated wastewater effectively through accumulation, adsorption, and metabolism. These mechanisms enable the microalgae to reduce the concentration of heavy metals and organic contaminants to levels that are considered non-toxic. However, several factors, such as microalgal strain, cultivation technique, and the type of pollutants, limit the understanding of the microalgal removal mechanism and efficiency. Furthermore, adopting novel technological advancements (e.g., nanotechnology) may serve as a viable approach to address the challenge of refractory pollutants and bioremediation process sustainability. Therefore, this review discusses the mechanism and the ability of different microalgal species to mitigate persistent refractory pollutants, such as industrial effluents, dyes, pesticides, and pharmaceuticals. Also, this review paper provided insight into the production of nanomaterials, nanoparticles, and nanoparticle-based biosensors from microalgae and the immobilization of microalgae on nanomaterials to enhance bioremediation process efficiency. This review may open a new avenue for future advancing research regarding a sustainable biodegradation process of refractory pollutants., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Microalgae offer a promising alternative for heavy metal removal, and the search for highly efficient strains is ongoing. This study investigated the potential of two microalgae, Coelastrella sp. BGV (Chlorophyta) and Arthronema africanum Schwabe & Simonsen (Cyanoprokaryota), to bind zinc ions (Zn 2 ⁺) and protect higher plants. Hydroponically grown pea ( Pisum sativum L.) seedlings were subjected to ZnSO 4 treatment for 7 days in either a nutrient medium (Knop) or a microalgal suspension. The effects of increasing Zn 2 ⁺ concentrations were evaluated through solution parameters, microalgal dry weight, pea growth (height, biomass), and physiological parameters, including leaf gas exchange, chlorophyll content, and normalized difference vegetation index (NDVI). Zinc accumulation in microalgal and plant biomass was also analyzed. The results revealed that microalgae increased pH and oxygen levels in the hydroponic medium while enhancing Zn accumulation in pea roots. At low ZnSO 4 concentrations (2-5 mM), microalgal suspensions stimulated pea growth and photosynthetic performance. However, higher ZnSO 4 levels (10-15 mM) caused Zn accumulation, leading to nutrient deficiencies and growth suppression in microalgae, which ultimately led to physiological disturbances in peas. Coelastrella sp. BGV exhibited greater tolerance to Zn stress and provided a stronger protective effect when co-cultivated with peas, highlighting its potential for phycoremediation applications.

Recently, the scale and frequency of harmful algae blooms (HABs) have gradually increased, posing a serious threat to human health, marine ecosystems and economic development. For early warning, a method is required that can quickly detect and monitor microalgae. It is proposed to use aptamer targeted to Prorocentrum minimum, along with exonuclease III (Exo III), gold nanoparticles, target single-stranded DNA and hairpin structure probe to construct a new method, i.e. aptamer-lateral flow dipstick (LFD) based on Exo III-assisted signal amplification assay (ALBEA). The key conditions, including signal amplification and LFD detection, are optimized. Under the optimal conditions, the detection limit of ALBEA was 1.25 cells mL -1 . The cross-reactivity test showed no positive result except for P. minimum, indicating that the method is highly specific. The anti-interference test confirmed that the technique was not affected by the presence of other microalgae. The tested results of P. minimum cultured under different nutrient conditions and different growth stages demonstrated that the method is not affected by the cell state. Furthermore, the test results of simulated natural water samples further validated the practicality of the ALBEA. In conclusion, the established ALBEA offers a sensitive, specific and user-friendly tool, which can be used for the rapid detection of P. minimum and also provides a reference for the detection of other microalgae., Competing Interests: Declarations. Competing Interests: The authors declare no competing interests., (© 2025. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: The study aimed to investigate the effects of Chlorella vulgaris and lysozyme on growth performance, diarrhea rate, immune function, plasma biochemical parameters, and gut microbiota and metabolites of weaned piglets., Methods: Thirty weaned Xiangcun black piglets (BW, 11.47 ± 1.13 kg) were randomly assigned to one of three treatment groups: corn-soybean meal-based basal diet (CON group), soybean meal replaced with 5% C. vulgaris (CHV group), and soybean meal replaced with 5% C. vulgaris and 100 mg/kg lysozyme (LYSO group)., Results: Growth performance was not affected by C. vulgaris or C. vulgaris with lysozyme supplementation, while soybean meal partially replaced by C. vulgaris without lysozyme reduced the diarrhea rate of weaned piglets. Plasma biochemical analysis showed that plasma albumin, alkaline phosphatase, and high-density lipoprotein-cholesterol (HDL-C) levels in the CHV group and the total cholesterol and HDL-C levels in the LYSO group were higher when compared with the CON group. The LYSO group had increased interleukin (IL)-10 level in the jejunum and IL-1β level in the ileum while having a decreasing IL-6 level in the jejunum of piglets. Additionally, although Firmicutes and Megashaera&#95;A abundances and short-chain fatty acid concentrations (including acetate, propionate, butyrate, and valerate) were reduced in the CHV group, but several beneficial bacteria (such as Actinobacteroita, Faecealibacterium, and Anaerovibrio ) abundances were increased in the LYSO group., Discussion: In summary, dietary C. vulgaris or C. vulgaris with lysozyme supplementation improved health of piglets in some contexts without affecting growth performance. Therefore, soybean meal replaced by 5% C. vulgaris with or without lysozyme as sustainable feed ingredients in piglet diets could be a viable alternative approach., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2025 Azad, Li, Ye, Qin, Zhu, Martinez and Kong.)

Controlling the spread of antibiotic-resistance genes (ARGs) under antibiotic stress has become an increasingly urgent issue. Microalgae possess the capability to remove antibiotics while concurrently inhibiting ARGs. Microalgae-bacteria systems can produce significant quantities of extracellular polymeric substances (EPS). However, the roles of EPS in the spread of ARGs have not been sufficiently explored, resulting in an insufficient understanding of the contribution of each EPS component and a lack of analysis on the complex interactions between EPS and ARGs. This study systematically explored the overlooked role of EPS in the transmission of ARGs within microalgae-bacteria systems. The current results showed that the potential of the microalgae-bacteria system for treating antibiotic wastewater. The tightly bound-EPS (TB-EPS) can acquire the higher absolute abundances of ARGs compared with the loosely bound-EPS (LB-EPS). The correlation coefficient between polysaccharides and TB-EPS ARGs was higher than that between polysaccharides and LB-EPS ARGs. The gene patterns of LB-EPS closely clustered with those of TB-EPS, while intracellular ARG gene patterns differed from both TB-EPS and LB-EPS. Metagenomic analyses indicated that the relative abundances of sul1 and sul2 were considerably higher at the beginning stage compared to the end stage. The abundance of Achromobacter, increased by the end stage, aligning with its potential to produce exopolysaccharide. Additionally, the absolute abundance of genes encoding exopolysaccharides (nagB and galE) and conjugative transfer transcription regulator (traF), increased over time. These findings enhanced our comprehension of the significance of EPS on the fate of ARGs in microalgae-bacteria systems during the treatment of antibiotic-contaminated wastewater., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier B.V. All rights reserved.)