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20 pages, 1585 KB

Open AccessArticle

Integrating C-Phycocyanin, and Polyhydroxybutyrate Recovery Using a Triphasic System: Experimental Design and Optimization in Thermotolerant Potamosiphon sp.

by Andrés F. Barajas-Solano

Phycology 2026, 6(1), 21; https://doi.org/10.3390/phycology6010021 - 1 Feb 2026

Cited by 1 | Viewed by 148

Abstract

This research assesses a triphasic extraction technique for the sequential retrieval of C-phycocyanin (C-PC) and polyhydroxybutyrate (PHB) from a thermotolerant Potamosiphon sp. strain. A two-stage design-of-experiments methodology was employed (Minimum Run Resolution V factorial design involving six variables, followed by a central composite [...] Read more.

This research assesses a triphasic extraction technique for the sequential retrieval of C-phycocyanin (C-PC) and polyhydroxybutyrate (PHB) from a thermotolerant Potamosiphon sp. strain. A two-stage design-of-experiments methodology was employed (Minimum Run Resolution V factorial design involving six variables, followed by a central composite design (CCD)) to optimize the chosen region. In the factorial stage, PHB ranged from 109.396 to 168.995 mg/g, and the model was significant (F = 22.63, p < 0.0001). Freeze-milling and vortexing were identified as critical elements, underscoring the importance of the t-butanol × (NH₄)₂SO₄ interaction for phase selectivity. The CCD concentrating on freeze-milling and vortex cycles yielded a robust quadratic model (F = 78.18, p < 0.0001), forecasting a peak PHB yield of 191.82 mg/g at six freeze-milling cycles and three vortex cycles (desirability 0.921), while maintaining t-butanol at 19.9 mL, t-butanol concentration at 94.7% (v/v), (NH₄)₂SO₄ at 49.9% (w/v), and vortex duration at 1.2 min. Ten separate trials validated the model’s accuracy, yielding an observed PHB of 191.5 mg/g, which closely matched the model’s prediction. The platform facilitates an integrated downstream process in which C-PC is recovered under moderate conditions before triphasic partitioning. This enables the simultaneous valorization of pigment, lipophilic fraction, and biopolymer inside a unified cyanobacterial biorefinery process. Full article

(This article belongs to the Special Issue Development of Algal Biotechnology)

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21 pages, 3602 KB

Open AccessArticle

Study on the Short-Term High-Temperature Response Mechanisms and Ethanolamine Metabolic Regulation in Desert Chlorella

by Nuerbiye Yisimayi, Liping Yang, Mingyang Sun, Xinyue Tang, Lingna Chen, Aisajiang Tuheti, Shanjiang Ai and Yongkun Chen

Phycology 2026, 6(1), 13; https://doi.org/10.3390/phycology6010013 - 8 Jan 2026

Viewed by 292

Abstract

Understanding the molecular basis of heat tolerance in microalgae is crucial for developing resilient strains for industrial biotechnology. This study identified two desert Chlorella strains, XDA024 (thermotolerant) and XDA121 (heat-sensitive), through short-term thermal screening. The thermotolerant strain XDA024 survived exposure to 50 °C [...] Read more.

Understanding the molecular basis of heat tolerance in microalgae is crucial for developing resilient strains for industrial biotechnology. This study identified two desert Chlorella strains, XDA024 (thermotolerant) and XDA121 (heat-sensitive), through short-term thermal screening. The thermotolerant strain XDA024 survived exposure to 50 °C for 3 h, whereas XDA121 succumbed within 1 h at 40 °C. Physiological analyses revealed that the superior heat resistance of XDA024 was associated with enhanced activities of key antioxidant enzymes, including superoxide dismutase, catalase, and peroxidase, which effectively mitigated oxidative damage, alongside an elevated proline content contributing to osmoregulation. Transcriptomic profiling under acute heat stress (45 °C, 3 h) revealed that the unique thermotolerance of XDA024 was underpinned by the upregulation of genes related to photosystem stability and lipid synthesis, processes supported by activated calcium signaling and antioxidant pathways. In contrast, XDA121 exhibited significant downregulation of photosynthesis-related genes and promoted lipid degradation, resulting in membrane instability. Exogenous application of phosphatidylethanolamine (PE) and monoethanolamine (MEA) markedly increased the survival rate of XDA121 by more than threefold, primarily by alleviating membrane damage through enhanced membrane integrity and modulated antioxidant enzyme activities. These findings indicate that thermotolerance in desert Chlorella (Chlorophyta) is governed by the integrated coordination of antioxidant defense mechanisms, lipid metabolism, and photosystem protection. This research provides crucial insights and practical strategies for engineering heat-resistant microalgal strains for sustainable biofuel and bioproduct production. Full article

(This article belongs to the Special Issue Development of Algal Biotechnology)

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17 pages, 1465 KB

Open AccessArticle

High-Solids Processing of Palmaria palmata for Feed Applications: Effects of Alkaline Autoclaving and Sequential Enzymatic Treatment

by Catarina Ramos-Oliveira, Marta Ferreira, Isabel Belo, Aires Oliva-Teles and Helena Peres

Phycology 2026, 6(1), 12; https://doi.org/10.3390/phycology6010012 - 8 Jan 2026

Viewed by 414

Abstract

Macroalgae are increasingly recognized as a valuable source of nutrients and bioactive compounds for animal nutrition, including for aquatic species. However, the complex structure of the macroalgal cell wall limits the accessibility of intracellular components, restricting their use in feeds. To overcome this [...] Read more.

Macroalgae are increasingly recognized as a valuable source of nutrients and bioactive compounds for animal nutrition, including for aquatic species. However, the complex structure of the macroalgal cell wall limits the accessibility of intracellular components, restricting their use in feeds. To overcome this limitation, macroalgal hydrolysis using various technological treatments has been tested, often employing a low solid-to-water ratio, which complicates downstream processing due to phase separation. In contrast, high-solids loading hydrolysis has the advantage of producing a single and consolidated fraction, simplifying subsequent processing and application. The present study assessed the effectiveness of high-solids loading water or alkaline (0.5 and 1N NaOH) autoclaving for 30 or 60 min, applied alone or followed by sequential enzymatic hydrolysis, using a xylanase-rich enzymatic complex aimed at promoting cell wall disruption and increasing the extractability of intracellular components in the red macroalga Palmaria palmata with minimal free water. The 1N NaOH treatment for 30 min decreased neutral and acid detergent fiber while increasing Folin–Ciocalteu total phenolic content (GAE) (expressed as gallic acid equivalent) and the water-soluble protein fraction and decreased crude protein, indicating enhanced extractability of these components. Microscopic examination showed relatively mild structural changes on the surface of P. palmata after high-solids loading alkaline (1N NaOH) autoclaving for 30 min. Following alkaline or water treatment, the enzymatic complex hydrolysis further increased the Folin–Ciocalteu total phenolic content (GAE), with minimal effects on NDF, ADF, or crude protein. Overall, these results showed that high-solids loading alkaline autoclaving, with or without subsequent enzymatic hydrolysis, effectively disrupts P. palmata cell walls and induces substantial modifications while simplifying processing by avoiding phase separation. Full article

(This article belongs to the Special Issue Development of Algal Biotechnology)

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19 pages, 3614 KB

Open AccessArticle

Physiological State of the Carotenogenic Microalga Coelastrella rubescens (Scenedesmaceae, Sphaeropleales) During Two-Stage Cultivation

by Irina Mansurova, Nataliya Dantsyuk, Irina Chubchikova, Elena Bocharova and Olga Krivenko

Phycology 2026, 6(1), 8; https://doi.org/10.3390/phycology6010008 - 5 Jan 2026

Viewed by 455

Abstract

A strain of aeroterrestrial green microalgae Coelastrella rubescens IBSS-156, isolated from an epilithic lichen, has been previously shown to efficiently produce green biomass and accumulate significant amounts of secondary carotenoids. In this study, using a two-stage batch culture, we analyzed time-course changes in [...] Read more.

A strain of aeroterrestrial green microalgae Coelastrella rubescens IBSS-156, isolated from an epilithic lichen, has been previously shown to efficiently produce green biomass and accumulate significant amounts of secondary carotenoids. In this study, using a two-stage batch culture, we analyzed time-course changes in variable chlorophyll a (Chl a) fluorescence parameters. Additionally, regression models were developed to correlate autofluorescence signals with spectrophotometric measurements of Chl a and total carotenoid content. Maximum quantum efficiency of photosystemII (F_v/F_m) remained high throughout the vegetative stage. At the end of this stage, under nutrient-limited conditions, the relative electron transport rate (rETR) declined to half its peak value during exponential growth. Stress induced a strong response in the algal photosynthetic apparatus during the early red stage. Within the first three days, F_v/F_m and rETR remained extremely low, but both increased sharply by day 5. During secondary carotenoid accumulation, fluorescence parameters remained at 70–80% of the vegetative-stage maximum, followed by a sharp decline toward the end of the red stage. Therefore, changes in variable fluorescence parameters can serve as markers of C. rubescens cellular physiology during biotechnological cultivation, denoting the completion of specific stages. Flow cytometry and pigment assay regression enabled real-time monitoring of C. rubescens biomass and carotenoids. Full article

(This article belongs to the Special Issue Development of Algal Biotechnology)

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21 pages, 1827 KB

Open AccessArticle

A Reliable Semi-Continuous Cultivation Mode for Stable High-Quality Biomass Production of Chlorella sorokiniana IPPAS C-1

by David A. Gabrielyan, Maria A. Sinetova, Boris V. Gabel, Alexander K. Gabrielian, Alexander Y. Starikov, Roman A. Voloshin, Alexandra Markelova, Grigoriy A. Savinykh, Natalia V. Shcherbakova and Dmitry A. Los

Phycology 2026, 6(1), 4; https://doi.org/10.3390/phycology6010004 - 1 Jan 2026

Viewed by 483

Abstract

The industrial cultivation of microalgae for high-value products faces significant challenges, particularly in maintaining long-term, cost-effective operations. Semi-continuous cultivation presents a promising solution to this problem. In this study, the green alga Chlorella sorokiniana IPPAS C-1 was cultivated in a flat-panel 5 L [...] Read more.

The industrial cultivation of microalgae for high-value products faces significant challenges, particularly in maintaining long-term, cost-effective operations. Semi-continuous cultivation presents a promising solution to this problem. In this study, the green alga Chlorella sorokiniana IPPAS C-1 was cultivated in a flat-panel 5 L photobioreactor under optimized conditions, with three biological replicates. We evaluated batch mode against three semi-continuous dilution fractions (50%, 75%, and 87.5%). The 75% dilution fraction demonstrated superior performance, achieving the highest biomass productivity with an average specific productivity of 1.36 g DW L⁻¹ day⁻¹ over seven harvest cycles. Furthermore, this regime ensured stable biochemical composition—including proteins, lipids, carbohydrates, and pigments—as well as a consistent lipid profile and sustained photosynthetic activity throughout the cultivation. These findings are useful for the development of scalable and efficient technological protocols for the industrial production of Chlorella in flat-panel photobioreactors. Full article

(This article belongs to the Special Issue Development of Algal Biotechnology)

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13 pages, 951 KB

Open AccessArticle

Assessment of the Use of Coconut Water as a Cultivation Medium for Limnospira (Arthrospira) platensis (Gomont): Effects on Productivity and Phycocyanin Concentration

by Maria Rafaele Oliveira Bezerra da Silva, Bruna Emanuelle Gomes do Nascimento, Maria Eduarda Moura Mendes, Rayane Oliveira Bezerra da Silva, Silvana de Fátima Ferreira da Silva, Romero Marcos Pedrosa Brandão Costa and Daniela de Araújo Viana Marques

Phycology 2025, 5(4), 82; https://doi.org/10.3390/phycology5040082 - 1 Dec 2025

Viewed by 672

Abstract

Due to the scarcity of sustainable inputs for photosynthetic microorganisms’ biotechnology, the search for natural substrates such as coconut water has gained prominence. This by-product is a substrate rich in macro- and micronutrients, as well as endogenous phytohormones that support microbial growth. In [...] Read more.

Due to the scarcity of sustainable inputs for photosynthetic microorganisms’ biotechnology, the search for natural substrates such as coconut water has gained prominence. This by-product is a substrate rich in macro- and micronutrients, as well as endogenous phytohormones that support microbial growth. In this context, this study aimed to use it as an alternative cultivation medium for Limnospira platensis (Gomont), formerly known as Arthrospira platensis, a high-value cyanobacterium. We evaluated growth parameters, phycocyanin concentration, purity, and biomass yield cultivated in coconut water and in SAG_1x medium, a modified Zarrouk medium. Over 35 days of cultivation, both media efficiently supported cyanobacterial growth. In coconut water, the specific growth rate was 0.305 d⁻¹, the maximum growth rate was 0.629 d⁻¹, and the productivity was 0.256 g L⁻¹ d⁻¹. In SAG_1x medium, the values obtained were 0.240 d⁻¹, 0.676 d⁻¹, and 0.218 g L⁻¹ d⁻¹, respectively. Phycocyanin obtained from cultivation in SAG_1x medium presented food-grade purity (OD620/OD280 ratio > 0.7), while in coconut water, it was 0.6. The pigment concentration and yield in SAG_1x (19.1 mg/L and 34.3%, respectively) also slightly exceeded those obtained with coconut water (14.3 mg/L and 25.5%, respectively). Despite this, the data reinforce the potential of coconut water as a viable and economically competitive alternative to conventional media for L. platensis production. Full article

(This article belongs to the Special Issue Development of Algal Biotechnology)

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14 pages, 825 KB

Open AccessArticle

Insecticidal Activity of Eco-Extracted Holopelagic Sargassum Against the Whitefly Bemisia tabaci Infesting Tomato Crops

by Chirelle Jabbour, Béatrice Rhino, Chloé Corbanini, Jean-Pascal Bergé, Kevin Hardouin and Nathalie Bourgougnon

Phycology 2025, 5(4), 79; https://doi.org/10.3390/phycology5040079 - 1 Dec 2025

Viewed by 734

Abstract

Massive strandings of holopelagic Sargassum cause major ecological and economic problems, but its conversion into bioproducts offers a sustainable alternative. This study assessed the potential of holopelagic Sargassum (S. fluitans and S. natans) collected in the Caribbean as ecofriendly insecticides against [...] Read more.

Massive strandings of holopelagic Sargassum cause major ecological and economic problems, but its conversion into bioproducts offers a sustainable alternative. This study assessed the potential of holopelagic Sargassum (S. fluitans and S. natans) collected in the Caribbean as ecofriendly insecticides against the whitefly Bemisia tabaci, a major pest of tomato crops. Extracts were produced using green methods: ultrasound-assisted extraction (UAE) and ultrasound-assisted enzymatic hydrolysis (UAEH) with enzymes cocktails. Biochemical analyses revealed high mineral and polysaccharide contents, varying with the extraction technique. Extracts were tested at 1–6% (w/v) using clip-cage (adults) and leaf-dip (eggs) methods. All extracts reduced adult survival, with UAE and UAEH-P/C extracts achieving over 50% mortality at ≥4% concentration after 48 h (LD₅₀: 3.9–4.5%). Egg mortality was significant only with UAE and UAEH-P extracts at 6% (LD₅₀: 1.9–2.8%). These results suggest insecticidal activity through both ingestion and cuticle/embryo disruption. Although enzymatic extraction did not markedly enhance biochemical yields, extracts showed, for the first time, promising biocidal and ovicidal properties. This research highlights holopelagic Sargassum as a renewable source of natural insecticidal compounds, supporting sustainable management of both invasive algal biomass and agricultural pests. Full article

(This article belongs to the Special Issue Development of Algal Biotechnology)

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14 pages, 1735 KB

Open AccessArticle

Antioxidant Status and CO₂ Biofixation of Chlorella sp. Strain Under Sequential Photoautotrophic Cultivation with Aphotic Induction of Biotechnologically Valuable Compounds Accumulation

by Aleksandr Yakoviichuk, Irina Maltseva, Angelika Kochubey, Yevhen Maltsev, Ekaterina Lysova and Evilina Sheludko

Phycology 2025, 5(4), 75; https://doi.org/10.3390/phycology5040075 - 17 Nov 2025

Viewed by 747

Abstract

Chlorella is a valuable object of biotechnology with high productivity of biomass and metabolites. The use of Chlorella for CO₂ binding in autotrophic metabolism is also discussed. Various types of stress are used to increase the yield of valuable metabolites. One of [...] Read more.

Chlorella is a valuable object of biotechnology with high productivity of biomass and metabolites. The use of Chlorella for CO₂ binding in autotrophic metabolism is also discussed. Various types of stress are used to increase the yield of valuable metabolites. One of the effective approaches may be dark stress. However, there is insufficient data to fully understand the effect of dark stress on productivity, biochemical parameters, the antioxidant system, and the rate of CO₂ fixation by Chlorella during the transfer from autotrophic culture to aphotic conditions. To study these processes, we used two-step cultivation. In the second step, the biomass was grown for 96 h on a BBM medium under standard lighting and in aphotic conditions. According to the results of the study, the metabolic systems of the studied strain of Chlorella sp. CAMU G–145 specifically react to cultivation under aphotic conditions. The greatest response was found in lipid–protein metabolism and the antioxidant defense system, which determines an increase in the overall antioxidant status of cells. At the same time, productivity, CO₂ absorption characteristics, and pigment composition of the photosynthetic system did not change after 96 h of darkening. In general, this approach is a promising strategy for increasing biotechnological productions efficiency. Full article

(This article belongs to the Special Issue Development of Algal Biotechnology)

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20 pages, 2403 KB

Open AccessArticle

Marine-Derived Mycosporine-like Amino Acids from Nori Seaweed: Sustainable Bioactive Ingredients for Skincare and Pharmaceuticals

by Manuela Gallego-Villada, Tatiana Muñoz-Castiblanco, Juan C. Mejía-Giraldo, Luis M. Díaz-Sánchez, Marianny Y. Combariza and Miguel Angel Puertas-Mejía

Phycology 2025, 5(4), 64; https://doi.org/10.3390/phycology5040064 - 1 Nov 2025

Viewed by 1203

Abstract

Mycosporine-like amino acids (MAAs) are multifunctional, UV-absorbing and antioxidant metabolites produced by marine algae, offering promising applications in biotechnology and dermocosmetic sciences. In this study, MAAs were sustainably extracted from nori seaweed (Porphyra spp.) using an ultrasound-assisted aqueous method, an eco-friendly approach [...] Read more.

Mycosporine-like amino acids (MAAs) are multifunctional, UV-absorbing and antioxidant metabolites produced by marine algae, offering promising applications in biotechnology and dermocosmetic sciences. In this study, MAAs were sustainably extracted from nori seaweed (Porphyra spp.) using an ultrasound-assisted aqueous method, an eco-friendly approach that ensures efficiency and industrial scalability. Chromatographic enrichment followed by MALDI-TOF mass spectrometry confirmed the presence of bioactive compounds, including porphyra-334, palythine, and myc-ornithine. The enriched fraction exhibited potent antioxidant activity (low IC₅₀ in DPPH and ABTS assays) and significant anti-elastase effects, highlighting its potential as a natural anti-aging agent. To optimize delivery, MAAs were incorporated into a stable water-in-oil nanoemulsion, which maintained droplet sizes below 400 nm and a low polydispersity index (PDI < 0.2) for up to four months. A randomized, double-blind clinical study in 20 volunteers further demonstrated that the MAA-based nanoemulsion significantly improved skin hydration (+53.6%) and reduced transepidermal water loss (TEWL), confirming its humectant and barrier-strengthening efficacy. These findings position Porphyra spp. as a sustainable marine resource for producing MAAs, and demonstrate their practical potential as natural, multifunctional ingredients in eco-conscious cosmetic and pharmaceutical formulations. Full article

(This article belongs to the Special Issue Development of Algal Biotechnology)

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21 pages, 8086 KB

Open AccessArticle

A Novel Approach Towards RSM-Based Optimization of LED-Illuminated Mychonastes homosphaera Culture, Emphasizing Input Energy: An Industrial Perspective of Microalgae Cultivation

by Doljit Borah, Khalifa S. H. Eldiehy, Khalid A. AL-Hothaly and Dhanapati Deka

Phycology 2025, 5(4), 62; https://doi.org/10.3390/phycology5040062 - 18 Oct 2025

Viewed by 981

Abstract

The growing demand for sustainable bioprocesses highlights microalgae as a promising source of renewable feedstock. However, high energy use for artificial lighting limits the commercial viability of photobioreactor systems. This study proposes an energy-optimized framework for cultivating Mychonastes homosphaera using LED illumination. The [...] Read more.

The growing demand for sustainable bioprocesses highlights microalgae as a promising source of renewable feedstock. However, high energy use for artificial lighting limits the commercial viability of photobioreactor systems. This study proposes an energy-optimized framework for cultivating Mychonastes homosphaera using LED illumination. The optimization was performed using Response Surface Methodology (RSM) with a Face-Centered Central Composite Design (FCCCD) to assess the interactive effects of light intensity, duration, airflow rate, and nitrogen concentration on biomass and lipid productivity. The performance of LED wavelengths was compared for biomass, lipid productivity, and energy consumption. RSM models were statistically significant (p < 0.01), and ANOVA had a high coefficient of determination (R²) for all LEDs. Maximum biomass productivity was 512.0 ± 12.23 mg L⁻¹ day⁻¹ with cool-white, followed by pink (401.33 ± 10.48), blue (342.66 ± 3.53), and red (189.6 ± 1.36). Cool-white consumed the least energy (228.6 Wh day⁻¹) to produce the maximum biomass, compared to blue (235.05 Wh day⁻¹), pink (240.0 Wh day⁻¹), and red (240.0 Wh day⁻¹). Lipid content was highest under red (22.84%), followed by pink (17.39%), blue (15.82%), and cool-white (8.96%). However, lipid productivity was highest under pink (69.8 mg L⁻¹ day⁻¹), followed by blue (54.2 mg L⁻¹ day⁻¹), cool-white (45.86 mg L⁻¹ day⁻¹), and red (43.3 mg L⁻¹ day⁻¹). Full article

(This article belongs to the Special Issue Development of Algal Biotechnology)

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12 pages, 1546 KB

Open AccessArticle

Effect of Photoperiod Duration and LED Light Quality on the Metabolite Profiles of High-Mountain Microalgal Isolates

by William H. Suárez Quintana, Ramón O. García-Rico, Janet B. García-Martínez, Néstor A. Urbina-Suarez, Germán L. López-Barrera and Andrés F. Barajas-Solano

Phycology 2025, 5(4), 59; https://doi.org/10.3390/phycology5040059 - 10 Oct 2025

Viewed by 970

Abstract

High-mountain microalgae exhibit remarkable adaptability to extreme environments, making them promising candidates for sustainable biorefineries. We evaluated how photoperiod (12:12, 18:6, 24:0 h) and LED spectra (cool white, full spectrum, red–blue 4:1) affect growth and metabolite formation in Chlorella sp. UFPS019 and Scenedesmus [...] Read more.

High-mountain microalgae exhibit remarkable adaptability to extreme environments, making them promising candidates for sustainable biorefineries. We evaluated how photoperiod (12:12, 18:6, 24:0 h) and LED spectra (cool white, full spectrum, red–blue 4:1) affect growth and metabolite formation in Chlorella sp. UFPS019 and Scenedesmus sp. UFPS021. Biomass peaked in Chlorella under red–blue 18:6 (≈1.8 g L⁻¹) and in Scenedesmus under red–blue 24:0 (≈1.7 g L⁻¹), revealing species-specific responses. Carbohydrate fractions were maximized under red–blue 12:12 in both species, and continuous light (24:0) depressed carbohydrate content—most notably under full spectrum. Protein content was highest under red–blue 18:6 in Chlorella sp. and under red–blue 12:12–18:6 in Scenedesmus sp. Lipid fractions increased with light duration, peaking under red–blue 18:6–24:0 in Chlorella and under red–blue 18:6–24:0—with Cool White 24:0 also high—in Scenedesmus sp. Although extended illumination favored lipids, intermediate photoperiods (12:12–18:6) provided better productivity-to-energy trade-offs and broader metabolic profiles. These results show that tuning spectral composition and photoperiod to species-specific physiology enables the targeted, energy-aware production of proteins, carbohydrates, or lipids; red–blue at intermediate durations is a robust, energy-efficient regime, whereas longer exposures can be used strategically when lipid enrichment is prioritized. Full article

(This article belongs to the Special Issue Development of Algal Biotechnology)

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22 pages, 3975 KB

Open AccessArticle

Comparative Phycoremediation Performance of Two Green Microalgal Strains Under Four Biomass Conditions for Industrial Wastewater Treatment

by Mostafa M. El-Sheekh, Reda M. Moghazy, Mai M. Hamoud and Mostafa E. Elshobary

Phycology 2025, 5(4), 53; https://doi.org/10.3390/phycology5040053 - 1 Oct 2025

Viewed by 922

Abstract

This study uses industrial wastewater from an aluminum factory to evaluate the phycoremediation efficiency of two green microalgal strains, Dictyosphaerium sp. and Tetradesmus obliquus. The industrial wastewater contained high levels of pollutants, including COD, ammonium, nitrate, phosphate, and heavy metal ions (Al [...] Read more.

This study uses industrial wastewater from an aluminum factory to evaluate the phycoremediation efficiency of two green microalgal strains, Dictyosphaerium sp. and Tetradesmus obliquus. The industrial wastewater contained high levels of pollutants, including COD, ammonium, nitrate, phosphate, and heavy metal ions (Al³⁺, Cu²⁺, Cr³⁺, Zn²⁺, Mn²⁺, Cd²⁺). Four biomass conditions were tested: free-living cells (active living cells), immobilized cells (entrapped within alginate), dried biomass (non-living dried cells), and acid-treated dried biomass (chemically modified for enhanced adsorption). Both strains demonstrated significant pollutant removal, with living biomass (free and immobilized) achieving the highest nutrient and organic pollutant removal, and non-living biomass (dried and acid-treated) being more efficient for rapid heavy metal removal. Tetradesmus obliquus showed superior performance across most parameters, while Dictyosphaerium sp. exhibited the highest aluminum removal (99.4%, reducing Al from 481.2 mg/L to 10.2 mg/L). These findings highlight the potential of microalgae-based approaches and support species-specific strategies for cost-effective and sustainable phycoremediation of industrial wastewater. Full article

(This article belongs to the Special Issue Development of Algal Biotechnology)

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16 pages, 1010 KB

Open AccessArticle

Productivity and Carbon Utilization of Three Green Microalgae Strains with High Biotechnological Potential Cultivated in Flat-Panel Photobioreactors

by David A. Gabrielyan, Maria A. Sinetova, Grigoriy A. Savinykh, Elena V. Zadneprovskaya, Maria A. Goncharova, Alexandra G. Markelova, Alexander K. Gabrielian, Boris V. Gabel and Nikolay V. Lobus

Phycology 2025, 5(3), 43; https://doi.org/10.3390/phycology5030043 - 2 Sep 2025

Cited by 2 | Viewed by 1687

Abstract

Microalgae biotechnology is increasingly applied across diverse fields, from food and medicine to energy and environmental protection, with strain selection being crucial for both target product accumulation and scalability potential. In this study, we for the first time assess the scalability of two [...] Read more.

Microalgae biotechnology is increasingly applied across diverse fields, from food and medicine to energy and environmental protection, with strain selection being crucial for both target product accumulation and scalability potential. In this study, we for the first time assess the scalability of two new promising green microalgae strains, Neochlorella semenenkoi IPPAS C-1210 and Desmodesmus armatus ARC-06, in 5-L flat-panel photobioreactors. The growth characteristics of each culture, along with their biochemical composition and CO₂ utilization efficiency, were examined and compared to the well-studied model strain Chlorella sorokiniana IPPAS C-1. While C-1 achieved the highest biomass concentration (7.1 ± 0.4 g DW L⁻¹ by day 8) and demonstrated superior specific productivity (1.5 ± 0.1 g DW L⁻¹ d⁻¹) and CO₂ utilization efficiency (average 25.4%, peaking at 34% on day 3), ARC-06 accumulated the highest starch content (51% of DW), twice that of C-1. Strain C-1210 showed intermediate performance, reaching 6.8 ± 0.8 g DW L⁻¹ biomass with a CUE of 22.7%, whereas ARC-06 had the lowest CUE (12.8%). These results, combined with proposed cultivation optimization strategies, provide a foundation for scaling up N. semenenkoi and D. armatus production in industrial flat-panel PBR systems. Full article

(This article belongs to the Special Issue Development of Algal Biotechnology)

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22 pages, 3276 KB

Open AccessArticle

Hybrid Machine Learning Models for Predicting the Impact of Light Wavelengths on Algal Growth in Freshwater Ecosystems

by Himaranga Sumanasekara, Harshi Jayasingha, Gayan Amarasooriya, Narada Dayarathne, Bandita Mainali, Lalantha Senevirathna, Ashoka Gamage and Othmane Merah

Phycology 2025, 5(2), 23; https://doi.org/10.3390/phycology5020023 - 8 Jun 2025

Viewed by 2774

Abstract

This study examines the influence of light wavelengths on the growth dynamics of five algal genera (Chlorella sp., Volvox sp., Gloeocapsa sp., Microspora sp., and Mougeotia sp.) in freshwater systems, using machine learning to optimize growth models. Natural light yielded the highest [...] Read more.

This study examines the influence of light wavelengths on the growth dynamics of five algal genera (Chlorella sp., Volvox sp., Gloeocapsa sp., Microspora sp., and Mougeotia sp.) in freshwater systems, using machine learning to optimize growth models. Natural light yielded the highest algal proliferation, increasing the total count from 90 to 1390 cells/mL in 30 days. Filtered wavelengths showed that blue light most effective (840 cells/mL), followed by red (490 cells/mL) and yellow (200 cells/mL), while green light minimally impacted growth (160 cells/mL). Genera-specific responses revealed that Gloeocapsa sp. and Mougeotia sp. thrived the most under blue light (240 and 750 cells/mL, respectively), with red and blue wavelengths generally enhancing growth across genera. Machine learning models achieved high accuracy (R² > 0.96 for total growth and R² > 0.8 for genera-specific and wavelength-based models), refining growth kinetics. These results suggest that spectral manipulation limiting blue/red wavelengths in water treatment to curb blooms while leveraging natural light for biofuel cultivation could optimize algal management. The integration of empirical data with machine learning offers a robust framework for predictive modeling in algal research and industrial applications. Full article

(This article belongs to the Special Issue Development of Algal Biotechnology)

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12 pages, 1299 KB

Open AccessArticle

Scale-Up Cultivation of the Dinoflagellate Durusdinium glynnii Under Varying Inoculum Percentages: Effects on Growth Performance and Fatty Acid Profile

by Pedro Rodrigues de Sena, Maria Eunice S. S. Lira, Deyvid Willame S. Oliveira, Barbara de Cassia S. Brandão, Jessika L. de Abreu, Watson Arantes Gama, Evando S. Araújo, Giustino Tribuzi, Alfredo O. Gálvez and Carlos Yure B. Oliveira

Phycology 2025, 5(2), 21; https://doi.org/10.3390/phycology5020021 - 2 Jun 2025

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Abstract

Microalgae are photosynthetic organisms with rapid growth and high biochemical diversity, capable of thriving in a variety of environments. Among them, dinoflagellates, particularly symbiotic species like Durusdinium glynnii, have gained attention due to their potential for biotechnological applications, especially in the production [...] Read more.

Microalgae are photosynthetic organisms with rapid growth and high biochemical diversity, capable of thriving in a variety of environments. Among them, dinoflagellates, particularly symbiotic species like Durusdinium glynnii, have gained attention due to their potential for biotechnological applications, especially in the production of valuable fatty acids. However, the delicate cultivation of dinoflagellates remains a challenge due to their sensitivity to shear stress and complex morphology. In this study, we evaluated the influence of inoculum percentage (10%, 25%, and 50%) on the growth performance and fatty acid profile of D. glynnii during a scale-up process from test tubes to a pilot-scale photobioreactor. Higher inoculum concentrations (50%) promoted faster acclimatization, higher specific growth rates (µ_max), and greater final biomass densities, optimizing the cultivation process. Meanwhile, lower inoculum concentrations (10%) favored the accumulation of polyunsaturated fatty acids, particularly DHA (C22:6n3), indicating a trade-off between biomass productivity and fatty acid biosynthesis. Overall, D. glynnii demonstrated robust adaptability, reinforcing its potential as a sustainable source of bioactive compounds. Further studies focusing on cellular and metabolic pathways are needed to better elucidate the mechanisms underlying lipid production and growth in this promising species. Full article

(This article belongs to the Special Issue Development of Algal Biotechnology)

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45 pages, 1495 KB

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Microalgae-Based Wastewater Treatment Processes for the Bioremediation and Valorization of Biomass: A Review

by Amritpreet Kaur Minhas, Suchitra Gaur, Sharon Sunny, Chaturya Paladugu, Gokare Aswathanarayana Ravishankar, Leonel Pereira and Ranga Rao Ambati

Phycology 2026, 6(1), 18; https://doi.org/10.3390/phycology6010018 - 1 Feb 2026

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Abstract

Conventional wastewater treatment methods often rely on energy-intensive physical and chemical processes that are costly and may generate secondary pollution. These limitations have prompted the exploration of more sustainable alternatives. Among them, phycoremediation, particularly using microalgae, has emerged as a promising strategy for [...] Read more.

Conventional wastewater treatment methods often rely on energy-intensive physical and chemical processes that are costly and may generate secondary pollution. These limitations have prompted the exploration of more sustainable alternatives. Among them, phycoremediation, particularly using microalgae, has emerged as a promising strategy for mitigating environmental pollution. Microalgae possess unique capabilities to sequester heavy metals, assimilate nutrients, and degrade emerging contaminants while simultaneously producing valuable biomass. The efficacy of microalgal bioremediation can be enhanced through omics-based approaches, which enable these biological agents to convert toxic compounds into non-toxic forms and improve ecosystem health. Additionally, forming microalgae–microorganism consortia can enhance process efficiency and cost-effectiveness. This review highlights multi-pronged strategies for pollutant mitigation in wastewater, focusing on environmentally and economically viable microalgal cultivation systems. It also identifies research gaps and discusses the potential for biomass valorization into economically important products. Full article

(This article belongs to the Special Issue Development of Algal Biotechnology)

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39 pages, 2038 KB

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Microalgal Biofactories: Sustainable Solutions for Nutrition and Cosmetics

by Khalifa S. H. Eldiehy, Yasmeen G. Haraz, Ibrahim S. Alkhazi, Malek Alrashidi, Mansoor Alghamdi, Norhan M. Elbanhawy and Omar Mohammad Atta

Phycology 2026, 6(1), 17; https://doi.org/10.3390/phycology6010017 - 1 Feb 2026

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Abstract

Microalgae have emerged as sustainable biofactories producing diverse bioactive compounds with significant applications in nutrition and cosmetics. Their high metabolic versatility makes them promising alternatives to conventional resources for addressing global challenges such as malnutrition, food insecurity, and environmental degradation. This review provides [...] Read more.

Microalgae have emerged as sustainable biofactories producing diverse bioactive compounds with significant applications in nutrition and cosmetics. Their high metabolic versatility makes them promising alternatives to conventional resources for addressing global challenges such as malnutrition, food insecurity, and environmental degradation. This review provides an integrated perspective on microalgal bioactives, highlighting their role in functional foods, dietary supplements, and maternal and infant nutrition, as well as their incorporation into cosmetic formulations for anti-aging, photoprotection, hydration, and microbiome support. Mechanistic insights reveal antioxidant, anti-inflammatory, and extracellular matrix-preserving effects, alongside UV absorption and barrier reinforcement. The review also discusses their biochemical diversity, mechanisms of action, safety, regulatory considerations, and emerging technologies for formulation and delivery. AI-driven and machine-learning approaches using microalgae for cosmetic and nutritional applications have also been discussed. Overall, microalgae serve as a cornerstone for next-generation nutraceuticals and cosmeceuticals, aligning with sustainability and circular-economy principles. Full article

(This article belongs to the Special Issue Development of Algal Biotechnology)

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