Search Results (3,873)

Phaeodactylum tricornutum is one of the most well-characterized microalgae and serves as a pivotal model diatom in global carbon fixation and the mediation of biogeochemical cycling of essential nutrients. Over the past few decades, the availability of a complete genome assembly, coupled with the development of robust DNA manipulation tools and efficient DNA delivery methodologies, has established P. tricornutum as a promising photosynthetic chassis for the sustainable bioproduction of high-value compounds, including fucoxanthin and eicosapentaenoic acid (EPA). This review systematically summarizes the research progress in the strain improvement toolkit of P. tricornutum, encompassing both genetic and non-genetic engineering strategies. It elaborates on the types and applications of its representative bioactive products, as well as the molecular mechanisms underlying key synthetic pathways. Additionally, this work synthesizes the research findings on the optimization of critical cultivation conditions (e.g., light, temperature, and nutrient composition) that modulate the growth and product synthesis of P. tricornutum. On this basis, the challenges encountered by P. tricornutum in industrial applications are proposed for further discussion, aiming to provide a reference for in-depth exploration of related research directions and facilitate the expansion of its application scope in the field of biomanufacturing. Full article

The marine unicellular red alga Rhodosorus marinus is a promising source of the valuable phycobiliprotein phycoerythrin and essential omega-3 polyunsaturated fatty acids (PUFAs), yet the environmental triggers for their optimal co-production remain to be fully elucidated. This study was conducted to investigate the effects of thermal and photic stress in terms of maximizing the yield of these high-value bioactive compounds. R. marinus was cultivated under a range of temperatures (18–24 °C) and light intensities (100–335 µmol photons m⁻² s⁻¹) to assess its physiological and biochemical responses, particularly focusing on lipid accumulation. This study investigates the effects of thermal (18–24 °C) and photic (100–335 µmol photons m⁻² s⁻¹) stress on the concurrent production of the valuable phycobiliprotein, phycoerythrin (PE), and essential omega-3 polyunsaturated fatty acids (PUFAs) in the marine red microalga Rhodosorus marinus. Fatty acid profiles were quantified using gas chromatography (GC), while pigment content was assessed via spectrophotometry. Statistical analyses, including one-way ANOVA and Tukey’s post hoc test, were employed to determine the significance of environmental effects. Our results demonstrate that a mild hypothermic condition of 18 °C significantly enhanced the production of eicosapentaenoic acid (EPA) compared to higher temperatures. Conversely, cell density was maximized at 22 °C. Under the 18 °C thermal regime, lower light intensities (100–185 µmol photons m⁻² s⁻¹) promoted a superior synthesis of both bioactive lipids and pigments. In conclusion, the strategic application of mild hypothermia combined with moderate light intensity is an effective approach to substantially boost the metabolic yield of high-value compounds in R. marinus, highlighting its potential as a sustainable source for nutraceutical and pharmaceutical applications. Full article

As agriculture faces increasing pressure to reduce pesticide residues and heavy metal accumulation in soils, marine microalgae are emerging as sustainable sources of biopesticides. Among them, Amphidinium carterae produces amphidinols (AMs), polyketide metabolites with strong antifungal activity against crop pathogens. Currently, large-scale AM production remains constrained by a limited understanding of AM biosynthesis across different A. carterae growth phases and by the lack of high-performing industrial strains. In this study, AM production dynamics were investigated in one wild-type (WT) and five mutagenized A. carterae strains. The production of bioactive AM18 and its sulfated inactive form AM19 was monitored through exponential, linear, and early stationary growth phases. The maximum AM productivity occurred between the linear and early stationary phase, with the average values of 5.58 ± 0.4 and 3.58 ± 0.2 µg/mL/day for AM18 and AM19, respectively. The AM18/AM19 ratio consistently decreased with the culture age, indicating that earlier harvesting favors higher proportions of bioactive AMs. UV mutagenesis increased the AM18 cell content by more than twofold and the growth rate by up to 20% in certain mutagenized strains compared to the WT strain, but did not enhance the volumetric AM productivity. Overall, these results identify optimal AM harvesting windows and clarify the potential benefits of mutagenesis strain improvement for industrial AM production improvement. Full article

Landfill leachate is a complex pollutant that contains high levels of nitrogenous compounds, heavy metals, and organic contaminants, posing serious environmental risks. This study presents an innovative and sustainable strategy for leachate biotransformation using the microalgae Chlorella sp. (UFPS_016, 017) and the cyanobacteria Oscillatoria sp. (UFPS_004) and Potamosiphon sp. (UFPS_008), integrating circular economy and Blue Economy principles. Strains were cultivated in 5% and 10% leachate under optimized photoperiods, LED illumination, and controlled CO₂ supplementation. The best performance was achieved by Oscillatoria sp. (UFPS_004) with biomass productivity of 0.3923 g L⁻¹ and carbohydrate accumulation up to 64.97% w/w, while Potamosiphon sp. (UFPS_008) achieved the highest PHB content (19.7% w/w). Chlorella sp. strains exhibited greater lipid accumulation, reaching 14.96% w/w, and produced phytohormones (Indole-3-acetic acid) with potential for agricultural applications. 20 L reactors validated scalability, maintaining productivity like that of small-scale systems. This dual-purpose bioprocess simultaneously detoxifies leachate and produces valuable bioproducts, including bioplastics, biofertilizers, and biofuels. The results demonstrate a feasible, low-cost, and eco-efficient biotechnology for landfill leachate management, contributing to waste valorization and environmental sustainability. Full article

The prevalence of diabetes and its worldwide co-morbidities is escalating. Therefore, the number of users of therapeutic peptides including insulin analogs and glucagon-like peptide 1 receptor agonists (GLP-1RAs), will unavoidably increase in the coming years. However, access to these two antidiabetic classes remains limited in some countries due to their high cost. Even when available, their long-term therapeutic efficiency is often compromised by challenges in sustained treatment adherence, mainly resulting from their mode of administration through repeated subcutaneous injections. This repeated invasive delivery not only affects patient comfort but also complicates long-term disease management and monitoring. Therefore, there is an urgent need to improve the accessibility, affordability, and long-term patient adherence to insulin and GLP-1RAs. In this review, we highlight as promising alternatives the potential of plants and microalgae to serve as host organisms, as well as the use of their polysaccharides as drug carriers, for the production of low-cost and non-invasive antidiabetic drugs. Full article

This study selected the typical eutrophication associated algae species Chlorella pyrenoidosa and Microcystis aeruginosa, from which alginate-like expolymers (ALEs) were extracted. Their composition, structural characteristics, and potential as biofertilizers were systematically analyzed. Results indicate that both C. pyrenoidosa-ALE (Cp-ALE) and M. aeruginosa-ALE (Ma-ALE) primarily comprise proteins and polysaccharides as functional components. Cp-ALE exhibited higher extraction yields (35.34 ± 4.32 mg·g⁻¹ VSS, volatile suspended solids) and richer growth-promoting constituents such as tryptophan, while Ma-ALE demonstrated higher aromaticity in its structure. Pot experiments further demonstrated that both ALEs exhibited a “low-concentration promotion, high-concentration inhibition” effect on ryegrass growth: at the optimal concentration (1:10,000), Cp-ALE and Ma-ALE increased ryegrass dry weight by 61.2% and 59.8%, respectively, with no significant difference compared to the algal whole-cell fertilizer (CF). This study has established a simple, environmentally friendly pathway for resource utilization of microalgal waste. Extracting ALEs effectively preserves plant-promoting components within microalgae, providing not only a sustainable solution for high-value utilization of eutrophication associated algae, but also a viable pathway for green agriculture and circular economic development. Full article

Interest in alternative protein sources has grown, with Spirulina, a microalga belonging to the genus Limnospira (formerly Arthrospira), emerging as a key option. Guided by sustainability principles, this study explored the gelling capacity and hydrogel-forming properties of integral Spirulina biomass (SpB), targeting applications in structured foods. Two experimental designs (DoE) were employed. One to identify key factors influencing hydrogel formation, and another to optimize the formulation (22 wt%, pH 5.6, thermal gelation at 90 °C). Syneresis analysis revealed that high SpB hydrogels experienced less water loss, with the 22% sample losing just 2.51% after 14 days, due to its dense, particulate morphology as observed by means of scanning electron microscopy. Rheological analysis confirmed the optimized formulation’s superior mechanical properties, with a storage modulus (G′) 24-times higher than the low concentration reference sample (~1890 Pa), remaining dominant over the loss modulus (G″) (G′ > G″) across the analysed frequency range, corroborating a strong elastic behaviour. Although the recovery tests showed partial recovery (27.1%) after high shear, the high residual stiffness (≈515 Pa) confirmed the material’s ability to maintain its shape. These results enabled successful 3D printing tests with the optimized hydrogel, pointing out its potential for innovative food applications in structured food design. Full article

This study evaluated the feasibility of using effluent from the anodic chamber of a microbial fuel cell (MFC), powered by real fruit and vegetable wastewater, as a cultivation medium for Tetraselmis subcordiformis, a microalga capable of bio-photolytic hydrogen production. In three experimental variants, different organic loading rates were applied in the anodic chamber, resulting in significant differences in effluent quality and its suitability as a culture medium. In contrast to the dominant MFC configurations, in which microalgae act as cathodic biocatalysts, the microbial fuel cell in this study was used as a source of the inevitable anode effluent, which was subsequently valorized as a cultivation medium for the marine microalga T. subcordiformis to support biomass and hydrogen production. In variants with moderate COD concentration and low lipid content, the highest biomass concentrations, ranging from 941 ± 104 mg VS/L to 1020 ± 108 mg VS/L, were obtained, along with the highest nitrogen assimilation efficiency (48.7–49.1%) and phosphorus assimilation efficiency (62.3–63.1%). The variant in which the culture medium contained the highest concentrations of COD, TSS, and lipids showed a substantial limitation of biomass growth to 745 ± 75 mg VS/L and lower nutrient removal efficiency (total nitrogen—42.3 ± 4.7%, total phosphorus—55.0 ± 5.0%). The obtained biomass was then used for H₂ production in a mineral photobiolytic medium. The highest total hydrogen production reached 184.7 ± 25.0 mL, while the specific hydrogen yield reached 193.7 ± 32.6 mL/g VS. Increased concentration of organic matter in the medium reduced total hydrogen production to 112.0 ± 14.8 mL, mainly due to lower biomass concentration, although the specific hydrogen yield remained high (153.4 ± 25.8 mL/g VS). The biogas composition was stable (H₂ 58.0–58.7%, CO₂ 35.3–35.9%, O₂ 6.0–6.2%). Full article

Phytochelatin synthases (PCSs) are pivotal enzymes in heavy metal detoxification, yet also implicated in sulfur homeostasis and redox regulation. In this study, we report the molecular and functional characterization of the PCS gene from the green alga Scenedesmus acutus (SaPCS), comparing wild-type and chromium-tolerant strains of this microalga. RT-qPCR, immunoblotting and mass spectrometry analyses revealed that SaPCS expression and protein abundance are primarily regulated by sulfur availability rather than by chromium stress. Two protein isoforms (~70 kDa full-length and ~34 kDa truncated) were detected, both more abundant in the chromium-tolerant strain than the wild-type and responsive to sulfur availability. Furthermore, three alternatively spliced transcript variants (SaPCSa, SaPCSb, SaPCSc) lacking the C-terminal domain coding region but retaining a functional or partially disrupted N-terminal catalytic domain were identified, contributing to the post-transcriptional diversification of PCSs. Mass spectrometry analyses showed negligible phytochelatin production in response to chromium treatment, indicating that detoxification of this metal in S. acutus relies mainly on glutathione (GSH) conjugation and the ascorbate–GSH antioxidant cycle. Overall, these results suggest that SaPCS may promote chromium tolerance by modulating sulfur and redox metabolism rather than by driving phytochelatin accumulation, highlighting the remarkable functional plasticity of PCSs in algal stress responses. Full article

Heavy metals such as copper are commonly found in aquatic environments. Microalgae can effectively adsorb heavy metals, while high concentrations impair their physiological and biochemical processes. This research investigated the impact of varying concentrations of sodium thiosulfate (Na₂S₂O₃) on the heavy metal tolerance of Chlorella vulgaris. Results showed that Na₂S₂O₃ and copper ions Cu(II) co-stress significantly improved the tolerance of C. vulgaris to Cu(II). To explore the mechanism, weighted gene co-expression network analysis (WGCNA) and trend analysis were applied to study the gene regulatory network under combined stress. A total of 103 significantly differentially expressed genes (DEGs) were identified. Further Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses revealed that the majority of DEGs are associated with photosynthesis, energy and liposome metabolisms. Physiological metrics, including chlorophyll content, photosynthetic activity, malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT), also aligned with bioinformatics results. This research offers a promising approach to reduce heavy metal pollution in water bodies. Full article

After numerous false starts, the global microalgae industry is re-emerging, driven by its potential to address critical challenges in food and nutrition, sustainable energy, nutraceuticals, cosmetics and pharmaceuticals, and climate change mitigation. Although technical advances in microalgae production show value adding potential, progressing from innovation to product launch and competitiveness is complex. It requires an integrated understanding of technology readiness, regulatory compliance, financial necessities, and market competition. This study presents a novel analytical framework underpinning a data-enabled, evidence-based approach to navigating the innovation pathways to market and beyond. The framework integrates value-add opportunities, identifying key stages faced in pre-competitive (including Technology Readiness Level (TRL), R&D spend, and patent trends), and competitive market stages (including product launches, product claims, market size, market share, growth/maturity, international markets, distribution channels, sectoral profile, and competitive landscape), aligned with regulatory requirements. Although not without limitations, such as incomplete data for emerging products, as well as reliance on secondary sources for product stage determination and market size estimates which can influence the accuracy of TRL classification and market potential estimates. This integration of multiple analyses can help in identifying market opportunities and business competitiveness via product, business, and industry level analyses in the pre-competitive (pre-market launch) and competitive (on market) landscapes. Building on the team’s interdisciplinary experience of developing interactive dashboards for food and beverage industries, and microalga processes, this paper provides an overview of the framework, which was designed to guide businesses and researchers in an emerging microalgae industry through the complex landscape of product development along regulatory and commercial pathways. Full article

Microbial fuel cells (MFC) are promising systems for wastewater treatment and electricity production; however, many technical and economic challenges must be overcome. One approach to improve MFC performance is the use of photosynthetic microorganisms at the cathode to supply oxygen and reduce aeration requirements. In this work, Chlorella sorokiniana was used as a cathodic biocatalyst, in order to supply oxygen while simultaneously obtaining high-value products. At the anode, an anaerobic mixed microbial culture was used as a biocatalyst. Different cathodic configurations were studied to evaluate the different cathodic catalytic mechanisms. Electrochemical characterization through cyclic voltammetry, polarization curves, biochemical analysis and SEM images was performed. Superior performance was achieved when employing microalgae as the cathodic oxygen source compared to systems relying on external aeration (128.7 mA/m² vs. 45.2 mA/m²). The addition of methylene blue and sodium bicarbonate improved the current density (194.8 mA/m² and 128.7 mA/m²). Results indicate that microalgae in the cathodic chamber could enhance MFC electrochemical performance and biomass production, boosting sustainable energy generation. Full article

Meat-processing wastewater (MPWW) is rich in nutrients and organic matter. This study assessed its potential as feedstock for microalgal biomass production while enabling wastewater treatment. In batch assays, the microalgae-based consortium grew in raw MPWW, and its synergy with the native wastewater microbial community enhanced the chemical oxygen demand (COD) removal rate. If suspended solids were pre-removed from wastewater, COD removing rates improved from 828.5 ± 60.5 to 1097.5 ± 22.2 mg L⁻¹ d⁻¹. In a raceway system operated in fed-batch mode with sieved and sedimented MPWW, COD removal was consistently achieved across feeding cycles, despite the variability in wastewater composition, reaching rates of up to 806.3 ± 0.0 mg L⁻¹ d⁻¹. Total nitrogen also decreased in most cycles. Microalgal biomass, estimated from total photosynthetic pigment’s concentration, increased from 0.4 to 17.9 µg mL⁻¹. The microalgae-based consortium became more diverse over time, harboring at the end, additional eukaryotic taxa such as protozoan grazers and fungi (e.g., Heterolobosea class and Trichosporonaceae and Dipodascaceae families), although their roles in removal processes remain unknown. This study highlights the potential use of real MPWW as feedstock for microalgal-based biomass production with concomitant carbon/nutrient load reduction, aligning its implementation with circular economy percepts. Full article

Efficient inorganic carbon supply is a common limitation in microalgal cultivation, particularly in waste-derived media such as anaerobic digestate. Carbonic anhydrase (CA) accelerates the interconversion of CO₂ and bicarbonate and may therefore enhance carbon utilisation under conditions where inorganic carbon is abundant but not readily available. In this study, crude CA-containing extracts (aCA) were prepared from Scenedesmus-dominated algal biomass, and CA activity was quantified using an esterase assay (EAA). Although EAA activities varied depending on biomass pretreatment (0.15–0.47 U g⁻¹ DW), the physiological response to extract addition was consistent. In batch cultures of Chlorella sorokiniana grown in diluted digestate, aCA supplementation increased the specific growth rate (SGR) by 21–82%. In contrast, stimulation in a mineral medium was minimal, indicating that the benefit of aCA addition is most apparent under reduced inorganic carbon availability. In semi-continuous cultivation, repeated extract addition sustained a higher biomass productivity over time (rather than a specific growth rate). These results demonstrate that crude microalgal extracts containing CA can improve growth performance in digestate-based cultures and may offer a simple, low-cost approach to enhancing inorganic carbon utilisation in waste-integrated algal production systems. Full article