Pub Date : 2026-01-11DOI: 10.1016/j.algal.2026.104527
Zhongliang Sun, Chenmei Bo, Shuonan Cao, Liqin Sun
High-ammonium dosing effectively suppresses protozoan contamination in Chlorella cultivation but causes growth inhibition, ammonia volatilization, and photosynthetic damage. Developing a sustainable strategy that mitigates these adverse effects while maintaining productivity is critical for large-scale applications. A staged cultivation strategy combining ammonium bicarbonate treatment with acetate-based recovery successfully restored algal growth and nitrogen utilization. Acetate maintained near-neutral pH, reduced ammonia stripping by 41%, and increased biomass productivity by 92% compared with CO2 control. Chlorophyll a fluorescence revealed faster recovery of Fv/Fm and ψ₀, indicating enhanced PSII function and photochemical efficiency. Acetate alleviates ammonium inhibition through physicochemical buffering and metabolic coordination, stabilizing pH, supplying carbon skeletons for nitrogen assimilation, and supporting thylakoid repair. This dual-function approach provides a simple, cost-effective, and scalable solution for open-pond cultivation, integrating contamination control with improved nitrogen-use efficiency and photosynthetic resilience.
{"title":"Acetate-enabled staged strategy in Chlorella vulgaris culture: Relieving ammonium inhibition while reducing ammonia stripping and enhancing protein content","authors":"Zhongliang Sun, Chenmei Bo, Shuonan Cao, Liqin Sun","doi":"10.1016/j.algal.2026.104527","DOIUrl":"10.1016/j.algal.2026.104527","url":null,"abstract":"<div><div>High-ammonium dosing effectively suppresses protozoan contamination in <em>Chlorella</em> cultivation but causes growth inhibition, ammonia volatilization, and photosynthetic damage. Developing a sustainable strategy that mitigates these adverse effects while maintaining productivity is critical for large-scale applications. A staged cultivation strategy combining ammonium bicarbonate treatment with acetate-based recovery successfully restored algal growth and nitrogen utilization. Acetate maintained near-neutral pH, reduced ammonia stripping by 41%, and increased biomass productivity by 92% compared with CO<sub>2</sub> control. Chlorophyll <em>a</em> fluorescence revealed faster recovery of <em>F</em><sub><em>v</em></sub><em>/F</em><sub><em>m</em></sub> and ψ₀, indicating enhanced PSII function and photochemical efficiency. Acetate alleviates ammonium inhibition through physicochemical buffering and metabolic coordination, stabilizing pH, supplying carbon skeletons for nitrogen assimilation, and supporting thylakoid repair. This dual-function approach provides a simple, cost-effective, and scalable solution for open-pond cultivation, integrating contamination control with improved nitrogen-use efficiency and photosynthetic resilience.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"94 ","pages":"Article 104527"},"PeriodicalIF":4.5,"publicationDate":"2026-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-10DOI: 10.1016/j.algal.2026.104526
Amina Lami Mohammed , Man Kee Lam , Uganeeswary Suparmaniam , Jun Wei Lim , Inn Shi Tan , Sie Yon Lau , Bridgid Lai Fui Chin , Peck Loo Kiew
Microalgae are well-known for their high lipid content, which can be converted into biodiesel, providing a renewable energy source. This study investigates the potential of microalgae to generate bioelectricity during cultivation, thereby providing an additional renewable energy source prior to biodiesel production. The research systematically investigates the effects of electrode material, pH, nutrient concentration and salinity on the growth, lipid accumulation and electrochemical performance of Chlorella vulgaris. The optimal performance was achieved using AlZn electrodes at pH 5.0, a nutrient concentration of 8% v/v and a salinity of 0.2M. Under these conditions, both lipid production and bioelectricity generation were enhanced, resulting in the highest bioelectricity output of 0.82 V and a lipid content of 35.5% wt., corresponding to the maximum lipid yield of 0.302 g/L. These findings demonstrate the dual benefit of high lipid yield and bioelectricity generation, underscoring the potential of electrode-integrated microalgae cultivation systems for the simultaneous production of both biofuels and bioelectricity, indicating their applicability as scalable and sustainable platforms for renewable energy solutions. This study highlights the synergistic enhancement of biofuel production and bioelectricity generation, emphasizing the importance of optimizing cultivation parameters for efficient and sustainable energy production.
{"title":"Optimizing electrode-integrated microalgae cultivation systems for simultaneous bioelectricity and lipid production","authors":"Amina Lami Mohammed , Man Kee Lam , Uganeeswary Suparmaniam , Jun Wei Lim , Inn Shi Tan , Sie Yon Lau , Bridgid Lai Fui Chin , Peck Loo Kiew","doi":"10.1016/j.algal.2026.104526","DOIUrl":"10.1016/j.algal.2026.104526","url":null,"abstract":"<div><div>Microalgae are well-known for their high lipid content, which can be converted into biodiesel, providing a renewable energy source. This study investigates the potential of microalgae to generate bioelectricity during cultivation, thereby providing an additional renewable energy source prior to biodiesel production. The research systematically investigates the effects of electrode material, pH, nutrient concentration and salinity on the growth, lipid accumulation and electrochemical performance of <em>Chlorella vulgaris</em>. The optimal performance was achieved using Al<img>Zn electrodes at pH 5.0, a nutrient concentration of 8% <em>v</em>/v and a salinity of 0.2M. Under these conditions, both lipid production and bioelectricity generation were enhanced, resulting in the highest bioelectricity output of 0.82 V and a lipid content of 35.5% wt., corresponding to the maximum lipid yield of 0.302 g/L. These findings demonstrate the dual benefit of high lipid yield and bioelectricity generation, underscoring the potential of electrode-integrated microalgae cultivation systems for the simultaneous production of both biofuels and bioelectricity, indicating their applicability as scalable and sustainable platforms for renewable energy solutions. This study highlights the synergistic enhancement of biofuel production and bioelectricity generation, emphasizing the importance of optimizing cultivation parameters for efficient and sustainable energy production.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"94 ","pages":"Article 104526"},"PeriodicalIF":4.5,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-10DOI: 10.1016/j.algal.2026.104525
Sahr Lamin Sumana , Gnoumasse Sidibe , Ahmed E. Elshafey , Damien Habinshuti , Agnes Mattia , Jusu Massaquoi , Sheku Tarawallie , Mukhtar Muhammad Abdullateef , Abubakar Shuaibu , Prince Tongor Mabey , Amidu Mansaray , Yang Xiaofei , Jiang Ruitong , Abdul Karim Meinday , Samuel Ayeh Osei , Joseph Saidu Sankoh , Alie Basma Conteh , Abdul Salami Bah , Md Mohidul Islam , Chernor A.U. Bah , Jianheng Zhang
This review finds that incorporating seaweed into aquafeeds can improve growth, immunity, and gut health, but its effectiveness is highly dependent on the fish species and the dosage used. The results show that incorporating seaweed into aquafeeds generally enhances fish growth, feed efficiency, immunity, metabolic activity, and gut health when used at low to moderate inclusion levels. Many species especially marine carnivores like Sparus aurata and omnivores like Oreochromis niloticus exhibit improved specific growth rate, stronger antioxidant enzyme activity, healthier intestinal structure, and more favorable gut microbiota profiles. Immune responses, including increased lysozyme, SOD, and cytokine expression, are consistently reported. However, low to moderate levels (e.g., 5–15% of the whole meal) are beneficial for many species, especially marine carnivores, while herbivores can tolerate higher levels. However, excessive inclusion can be harmful, impairing digestion and causing stress. Key safety concerns include the potential for seaweeds to accumulate heavy metals and iodine, requiring careful sourcing and processing. When applied judiciously with species-specific formulations, seaweeds are a viable functional ingredient that can enhance aquaculture sustainability, reduce environmental impact, and improve biosecurity.
{"title":"Seaweed as a functional feed additive in aquaculture: Efficacy, safety, and fish species-specific optimization","authors":"Sahr Lamin Sumana , Gnoumasse Sidibe , Ahmed E. Elshafey , Damien Habinshuti , Agnes Mattia , Jusu Massaquoi , Sheku Tarawallie , Mukhtar Muhammad Abdullateef , Abubakar Shuaibu , Prince Tongor Mabey , Amidu Mansaray , Yang Xiaofei , Jiang Ruitong , Abdul Karim Meinday , Samuel Ayeh Osei , Joseph Saidu Sankoh , Alie Basma Conteh , Abdul Salami Bah , Md Mohidul Islam , Chernor A.U. Bah , Jianheng Zhang","doi":"10.1016/j.algal.2026.104525","DOIUrl":"10.1016/j.algal.2026.104525","url":null,"abstract":"<div><div>This review finds that incorporating seaweed into aquafeeds can improve growth, immunity, and gut health, but its effectiveness is highly dependent on the fish species and the dosage used. The results show that incorporating seaweed into aquafeeds generally enhances fish growth, feed efficiency, immunity, metabolic activity, and gut health when used at low to moderate inclusion levels. Many species especially marine carnivores like <em>Sparus aurata</em> and omnivores like <em>Oreochromis niloticus</em> exhibit improved specific growth rate, stronger antioxidant enzyme activity, healthier intestinal structure, and more favorable gut microbiota profiles. Immune responses, including increased lysozyme, SOD, and cytokine expression, are consistently reported. However, low to moderate levels (e.g., 5–15% of the whole meal) are beneficial for many species, especially marine carnivores, while herbivores can tolerate higher levels. However, excessive inclusion can be harmful, impairing digestion and causing stress. Key safety concerns include the potential for seaweeds to accumulate heavy metals and iodine, requiring careful sourcing and processing. When applied judiciously with species-specific formulations, seaweeds are a viable functional ingredient that can enhance aquaculture sustainability, reduce environmental impact, and improve biosecurity.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"94 ","pages":"Article 104525"},"PeriodicalIF":4.5,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-10DOI: 10.1016/j.algal.2026.104524
Qian Deng , Yongxin Zhang , Ziqing Liu , Bohan Yu , Chengwu Zhang , Miao Cui , Baoyan Gao
Psychrotolerant and psychrophilic microalgae have developed diverse strategies to survive in cold environments through long-term adaptation and evolution. In this study, we examined the cold-tolerance mechanisms of the filamentous yellow-green alga Heterococcus viridis at morphological, physiological, and transcriptomic levels. Our findings show that H. viridis exhibits a complex life cycle involving multiple cellular morphologies, including zoosporangia, zoospores, vegetative cells, coccoid cell clusters, and irregularly branching filaments. When shifted from ambient temperature to 5 ± 1 °C, H. viridis exhibited marked physiological changes: motile zoospore formation was strongly induced, total lipid content increased considerably during the later stages of cold acclimation, while total protein and carbohydrate contents decreased. Transcriptomic analysis revealed that genes associated with flagella, cilia, and motility were upregulated during zoospore formation. During cold acclimation, key genes involved in polyunsaturated fatty acid synthesis were significantly upregulated, along with genes encoding enzymes of the phosphatidylinositol signaling pathway, including protein kinase C and calcium-dependent protein kinase. Cold-shock protein-related DNA domains were activated, whereas heat-shock protein-related genes were suppressed. Together, these regulatory responses clarify the survival strategies of H. viridis under cold stress, underscoring the complex interplay of morphological plasticity, metabolic transformation, and gene expression regulation that supports cold tolerance.
{"title":"Cold adaptation mechanisms in Heterococcus viridis: Insights from morphological, physiological, and transcriptomic analyses","authors":"Qian Deng , Yongxin Zhang , Ziqing Liu , Bohan Yu , Chengwu Zhang , Miao Cui , Baoyan Gao","doi":"10.1016/j.algal.2026.104524","DOIUrl":"10.1016/j.algal.2026.104524","url":null,"abstract":"<div><div>Psychrotolerant and psychrophilic microalgae have developed diverse strategies to survive in cold environments through long-term adaptation and evolution. In this study, we examined the cold-tolerance mechanisms of the filamentous yellow-green alga <em>Heterococcus viridis</em> at morphological, physiological, and transcriptomic levels. Our findings show that <em>H. viridis</em> exhibits a complex life cycle involving multiple cellular morphologies, including zoosporangia, zoospores, vegetative cells, coccoid cell clusters, and irregularly branching filaments. When shifted from ambient temperature to 5 ± 1 °C, <em>H. viridis</em> exhibited marked physiological changes: motile zoospore formation was strongly induced, total lipid content increased considerably during the later stages of cold acclimation, while total protein and carbohydrate contents decreased. Transcriptomic analysis revealed that genes associated with flagella, cilia, and motility were upregulated during zoospore formation. During cold acclimation, key genes involved in polyunsaturated fatty acid synthesis were significantly upregulated, along with genes encoding enzymes of the phosphatidylinositol signaling pathway, including protein kinase C and calcium-dependent protein kinase. Cold-shock protein-related DNA domains were activated, whereas heat-shock protein-related genes were suppressed. Together, these regulatory responses clarify the survival strategies of <em>H. viridis</em> under cold stress, underscoring the complex interplay of morphological plasticity, metabolic transformation, and gene expression regulation that supports cold tolerance.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"94 ","pages":"Article 104524"},"PeriodicalIF":4.5,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-10DOI: 10.1016/j.algal.2026.104523
Yue Zhou , Jian Zhou , Bin Li , Yajie Xiao , Fuhua Peng , Leipeng Cao
The growth, chlorophyll a, carotenoid, and protein content of Arthrospira platensis (A. platensis) showed a dose-dependent decrease as the selenium-to-sulfur (Se/S) molar ratio increased from 2.0 to 16.0. The optimal Se/S molar ratio for biomass production and organic Se accumulation was found to be 4.0, yielding 0.80 g/L of biomass and 0.38 mg/g of organic Se (based on dried cell weight (DCW) at Se concentration of 40 mg/L. At Se/S molar ratio of 2.0–8.0, A. platensis responded to Se-induced oxidative stress by significantly upregulating the activities of key antioxidant enzymes-SOD, CAT, and GSH-Px, intracellular levels of ROS and MDA showed a slight increase, leading to uncontrolled accumulation of reactive oxygen species and consequent severe damage to the cell membrane. Proteomic analysis revealed 74 up-regulated and 98 down-regulated differentially expressed proteins (DEPs) between the Se/S molar ratio of 4.0 and the control (Se/S molar ratio of 0.19). The down-regulated DEPs were associated with photosynthesis, glycolysis, amino acid biosynthesis, oxidative stress response, and ribosomal structure, correlating with the observed reduction in biomass and biochemical synthesis. In contrast, up-regulated DEPs related to membrane transport, translation, and metal-binding proteins provided a mechanistic explanation for the enhanced organic selenium enrichment. This study clarifies the biological effects of Se/S molar ratio on the growth, Se speciation, and biochemical composition of A. platensis, and provides valuable insights for future genetic engineering approaches aimed at optimizing organic Se accumulation.
{"title":"Selenium accumulation in Arthrospira platensis under sulfur-limited conditions: modulation of selenium/sulfur molar ratio","authors":"Yue Zhou , Jian Zhou , Bin Li , Yajie Xiao , Fuhua Peng , Leipeng Cao","doi":"10.1016/j.algal.2026.104523","DOIUrl":"10.1016/j.algal.2026.104523","url":null,"abstract":"<div><div>The growth, chlorophyll <em>a</em>, carotenoid, and protein content of <em>Arthrospira platensis</em> (<em>A. platensis</em>) showed a dose-dependent decrease as the selenium-to-sulfur (Se/S) molar ratio increased from 2.0 to 16.0. The optimal Se/S molar ratio for biomass production and organic Se accumulation was found to be 4.0, yielding 0.80 g/L of biomass and 0.38 mg/g of organic Se (based on dried cell weight (DCW) at Se concentration of 40 mg/L. At Se/S molar ratio of 2.0–8.0, <em>A. platensis</em> responded to Se-induced oxidative stress by significantly upregulating the activities of key antioxidant enzymes-SOD, CAT, and GSH-Px, intracellular levels of ROS and MDA showed a slight increase, leading to uncontrolled accumulation of reactive oxygen species and consequent severe damage to the cell membrane. Proteomic analysis revealed 74 up-regulated and 98 down-regulated differentially expressed proteins (DEPs) between the Se/S molar ratio of 4.0 and the control (Se/S molar ratio of 0.19). The down-regulated DEPs were associated with photosynthesis, glycolysis, amino acid biosynthesis, oxidative stress response, and ribosomal structure, correlating with the observed reduction in biomass and biochemical synthesis. In contrast, up-regulated DEPs related to membrane transport, translation, and metal-binding proteins provided a mechanistic explanation for the enhanced organic selenium enrichment. This study clarifies the biological effects of Se/S molar ratio on the growth, Se speciation, and biochemical composition of <em>A. platensis</em>, and provides valuable insights for future genetic engineering approaches aimed at optimizing organic Se accumulation.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"94 ","pages":"Article 104523"},"PeriodicalIF":4.5,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-07DOI: 10.1016/j.algal.2026.104519
Yu Jiang , Hao Ning , Min Liu , Zhixin Wei , Min Wu , Xingyu Yan , Peihong Shen , Jian Jin , Luodong Huang
This study investigated the synergistic effects of diverse active compounds in the aqueous extracts of the filamentous alga Klebsormidium sp. (GXU-A8) and the single-celled alga Vischeria stellata (GXU-A13) on maize growth promotion. Using sodium nitrate as the nitrogen source at an initial concentration of 9 mmol/L, GXU-A8 biomass reached 4.73 g/L, while GXU-A13 biomass reached 7.96 g/L. Water-soluble metabolic components were extracted from the obtained biomass of both microalgae. The aqueous extracts of GXU-A8 and GXU-A13 contained 397 and 504 metabolic compounds, respectively, with 124 compounds shared between them. Notably, GXU-A8 was characterized by Linamarin (5.75 %) and GXU-A13 by Choline Alfoscerate (3.36 %). Network analysis revealed that GXU-A8 activated growth-related pathways (chromosome regulation, protein folding, signaling), while GXU-A13 enhanced stress resistance through distinct pathways (terpenoid/polyketide metabolism, photosynthetic carbon fixation, nucleotide metabolism). Molecular docking confirmed key target interactions for each strain (Estriol for GXU-A8, Guanine/Arabinosylhypoxanthine for GXU-A13), consistent with the respective roles of GXU-A8 in promoting growth under non-stress conditions and GXU-A13 in enhancing stress Protection. This study applied network pharmacology and molecular docking to elucidate microalgae-plant interactions for the precise application of bio-stimulant.
{"title":"Elucidating the growth effects of Klebsormidium sp. and Vischeria stellata on maize using network pharmacology and experimental validation","authors":"Yu Jiang , Hao Ning , Min Liu , Zhixin Wei , Min Wu , Xingyu Yan , Peihong Shen , Jian Jin , Luodong Huang","doi":"10.1016/j.algal.2026.104519","DOIUrl":"10.1016/j.algal.2026.104519","url":null,"abstract":"<div><div>This study investigated the synergistic effects of diverse active compounds in the aqueous extracts of the filamentous alga <em>Klebsormidium</em> sp. (GXU-A8) and the single-celled alga <em>Vischeria stellata</em> (GXU-A13) on maize growth promotion. Using sodium nitrate as the nitrogen source at an initial concentration of 9 mmol/L, GXU-A8 biomass reached 4.73 g/L, while GXU-A13 biomass reached 7.96 g/L. Water-soluble metabolic components were extracted from the obtained biomass of both microalgae. The aqueous extracts of GXU-A8 and GXU-A13 contained 397 and 504 metabolic compounds, respectively, with 124 compounds shared between them. Notably, GXU-A8 was characterized by Linamarin (5.75 %) and GXU-A13 by Choline Alfoscerate (3.36 %). Network analysis revealed that GXU-A8 activated growth-related pathways (chromosome regulation, protein folding, signaling), while GXU-A13 enhanced stress resistance through distinct pathways (terpenoid/polyketide metabolism, photosynthetic carbon fixation, nucleotide metabolism). Molecular docking confirmed key target interactions for each strain (Estriol for GXU-A8, Guanine/Arabinosylhypoxanthine for GXU-A13), consistent with the respective roles of GXU-A8 in promoting growth under non-stress conditions and GXU-A13 in enhancing stress Protection. This study applied network pharmacology and molecular docking to elucidate microalgae-plant interactions for the precise application of bio-stimulant.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"94 ","pages":"Article 104519"},"PeriodicalIF":4.5,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-07DOI: 10.1016/j.algal.2026.104521
Laura Vitale , Antonio Fuentes-Lema , Rosa Maria Sepe , Heethaka Krishantha Sameera de Zoysa , Dario Righelli , Cristina Sobrino , Giovanna Romano , Valeria Di Dato
Prostaglandins (PGs) are bioactive lipid compounds involved in physiological and environmental responses in various organisms. While their biosynthesis has been well studied in animals, recent evidence highlighted that diatoms also possess the genetic machinery for PGs synthesis; however, their function remains largely unexplored. This study investigates the diurnal oscillation of PGs pathway gene expression in Skeletonema marinoi under different environmental conditions, including variations in light intensity, temperature, and CO₂ concentration. Using two distinct strains, FE7 and FE60, we analysed the expression dynamics of three key enzymes involved in the prostaglandin biosynthesis: cyclooxygenase-1 (COX-1), microsomal prostaglandin E synthase (PTGES), and prostaglandin-H2 D-isomerase (PTGDS). Our results indicate strain-specific responses to environmental conditions that significantly altered the expression profiles of all three genes, with FE7 exhibiting greater sensitivity to temperature and light fluctuations compared to FE60. High CO₂ levels appear to positively influence the expression of COX and PTGDS and negatively those of PTGES, suggesting a potential role in modulating the production of different PGs, although the function of PGs in diatoms remains unclear. These findings provide preliminary insights into the molecular response of diatoms to environmental changes, contribute to exploring the potential role of PGs in diatoms, and highlight their potential ecological significance in phytoplankton communities, which remains speculative without functional assays and metabolite profiling by LC-MS/MS. To strengthen these findings, future studies should correlate gene expression with physiological indicators such as growth rate, cell morphology, and stress markers.
{"title":"Diurnal oscillation of prostaglandin pathway gene expression in Skeletonema marinoi under different environmental conditions","authors":"Laura Vitale , Antonio Fuentes-Lema , Rosa Maria Sepe , Heethaka Krishantha Sameera de Zoysa , Dario Righelli , Cristina Sobrino , Giovanna Romano , Valeria Di Dato","doi":"10.1016/j.algal.2026.104521","DOIUrl":"10.1016/j.algal.2026.104521","url":null,"abstract":"<div><div>Prostaglandins (PGs) are bioactive lipid compounds involved in physiological and environmental responses in various organisms. While their biosynthesis has been well studied in animals, recent evidence highlighted that diatoms also possess the genetic machinery for PGs synthesis; however, their function remains largely unexplored. This study investigates the diurnal oscillation of PGs pathway gene expression in <em>Skeletonema marinoi</em> under different environmental conditions, including variations in light intensity, temperature, and CO₂ concentration. Using two distinct strains, FE7 and FE60, we analysed the expression dynamics of three key enzymes involved in the prostaglandin biosynthesis: cyclooxygenase-1 (COX-1), microsomal prostaglandin E synthase (PTGES), and prostaglandin-H2 D-isomerase (PTGDS). Our results indicate strain-specific responses to environmental conditions that significantly altered the expression profiles of all three genes, with FE7 exhibiting greater sensitivity to temperature and light fluctuations compared to FE60. High CO₂ levels appear to positively influence the expression of COX and PTGDS and negatively those of PTGES, suggesting a potential role in modulating the production of different PGs, although the function of PGs in diatoms remains unclear. These findings provide preliminary insights into the molecular response of diatoms to environmental changes, contribute to exploring the potential role of PGs in diatoms, and highlight their potential ecological significance in phytoplankton communities, which remains speculative without functional assays and metabolite profiling by LC-MS/MS. To strengthen these findings, future studies should correlate gene expression with physiological indicators such as growth rate, cell morphology, and stress markers.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"94 ","pages":"Article 104521"},"PeriodicalIF":4.5,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-07DOI: 10.1016/j.algal.2026.104516
Jie Zhang , Fenfang Zhang , Kungang Pan , Dailin Liu , Tao Sun , Lei Chen , Weiwen Zhang
Transcriptional regulators play a crucial role in cyanobacterial growth, development, and response to abiotic stresses. Our previous work demonstrated that the transcriptional regulator Pex and its target gene Synpcc7942_2038 (encoding a putative transcription factor) were associated with acid stress response in Synechococcus elongatus PCC 7942. However, their regulatory mechanisms remain unclear. To address this, DNA affinity purification sequencing (DAP-seq) and chromatin immunoprecipitation sequencing (ChIP-seq) assays were employed to screen their target genes. Subsequently, protein-DNA interactions were validated through electrophoretic mobility shift assay (EMSA). The results showed that Pex binds to the promoter regions of Synpcc7942_0316 (encoding a hypothetical protein), Synpcc7942_2038 (encoding a hypothetical transcriptional regulator), and gcvT (Synpcc7942_2308, encoding a glycine cleavage T-protein). Among these, Synpcc7942_2038 and gcvT were indispensable for acid resistance. Notably, GcvT might participate in acid tolerance by modulating glycine metabolism and maintaining intracellular pH homeostasis. Its deletion led to reduced ammonia levels and a decreased intracellular pH, thereby impairing acid resistance. Furthermore, the Synpcc7942_2038 protein regulates the expression of scrK (Synpcc7942_0116, encoding fructokinase). Under acidic conditions, ΔscrK strain exhibited reduced fructose levels and impaired extracellular polysaccharide (EPS) production, indicating its role in cell envelope protection. In addition, ΔscrK strain accumulated 57 % less sucrose than wild type under 275 mM NaCl stress, directly compromising salt tolerance. Based on these findings, we propose a Pex-centered transcriptional regulatory model for acid and salt resistance in S. elongatus PCC 7942.
转录调节剂在蓝藻的生长、发育和对非生物胁迫的反应中起着至关重要的作用。我们之前的工作表明，转录调节因子Pex及其靶基因Synpcc7942_2038（编码一个假定的转录因子）与长聚球菌PCC 7942的酸胁迫反应有关。然而，它们的监管机制仍不清楚。为了解决这个问题，采用DNA亲和纯化测序（DAP-seq）和染色质免疫沉淀测序（ChIP-seq）检测来筛选它们的靶基因。随后，通过电泳迁移位移测定（EMSA）验证蛋白质- dna相互作用。结果表明，Pex结合到Synpcc7942_0316（编码一种假设的蛋白质）、Synpcc7942_2038（编码一种假设的转录调节因子）和gcvT（编码一种甘氨酸裂解t蛋白）的启动子区域。其中，Synpcc7942_2038和gcvT是耐酸不可或缺的。值得注意的是，GcvT可能通过调节甘氨酸代谢和维持细胞内pH稳态参与酸耐受性。它的缺失导致氨水平降低和细胞内pH值降低，从而损害了耐酸能力。此外，Synpcc7942_2038蛋白调控scrK （Synpcc7942_0116，编码果糖激酶）的表达。在酸性条件下，ΔscrK菌株表现出果糖水平降低和细胞外多糖（EPS）产生受损，表明其在细胞包膜保护中起作用。此外，ΔscrK菌株在275 mM NaCl胁迫下的蔗糖积累量比野生型少57%，直接影响了耐盐性。在此基础上，我们提出了一个以pex为中心的长叶稻PCC 7942耐酸、耐盐转录调控模型。
{"title":"Mechanisms of acid tolerance mediated by the transcription regulator Pex in Synechococcus elongatus PCC 7942","authors":"Jie Zhang , Fenfang Zhang , Kungang Pan , Dailin Liu , Tao Sun , Lei Chen , Weiwen Zhang","doi":"10.1016/j.algal.2026.104516","DOIUrl":"10.1016/j.algal.2026.104516","url":null,"abstract":"<div><div>Transcriptional regulators play a crucial role in cyanobacterial growth, development, and response to abiotic stresses. Our previous work demonstrated that the transcriptional regulator Pex and its target gene Synpcc7942_2038 (encoding a putative transcription factor) were associated with acid stress response in <em>Synechococcus elongatus</em> PCC 7942. However, their regulatory mechanisms remain unclear. To address this, DNA affinity purification sequencing (DAP-seq) and chromatin immunoprecipitation sequencing (ChIP-seq) assays were employed to screen their target genes. Subsequently, protein-DNA interactions were validated through electrophoretic mobility shift assay (EMSA). The results showed that Pex binds to the promoter regions of Synpcc7942_0316 (encoding a hypothetical protein), Synpcc7942_2038 (encoding a hypothetical transcriptional regulator), and <em>gcvT</em> (Synpcc7942_2308, encoding a glycine cleavage T-protein). Among these, Synpcc7942_2038 and <em>gcvT</em> were indispensable for acid resistance. Notably, GcvT might participate in acid tolerance by modulating glycine metabolism and maintaining intracellular pH homeostasis. Its deletion led to reduced ammonia levels and a decreased intracellular pH, thereby impairing acid resistance. Furthermore, the Synpcc7942_2038 protein regulates the expression of <em>scrK</em> (Synpcc7942_0116, encoding fructokinase). Under acidic conditions, Δ<em>scrK</em> strain exhibited reduced fructose levels and impaired extracellular polysaccharide (EPS) production, indicating its role in cell envelope protection. In addition, Δ<em>scrK</em> strain accumulated 57 % less sucrose than wild type under 275 mM NaCl stress, directly compromising salt tolerance. Based on these findings, we propose a Pex-centered transcriptional regulatory model for acid and salt resistance in <em>S. elongatus</em> PCC 7942.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"94 ","pages":"Article 104516"},"PeriodicalIF":4.5,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Accurate measurement of protein content in algal biomass is essential for assessing its suitability for food, feed, and biofuel applications. The conventional standard, the Kjeldahl method, relies on a nitrogen-to-protein conversion factor that is both species- and growth-condition-dependent, introducing potential variability. Furthermore, the robust cell walls of many algal species hinder efficient protein extraction for direct measurement, leading to inconsistent results across laboratories. A significant portion of the protein content may also be located within the cell wall itself. To address these limitations, we evaluated an alternative approach based on the ninhydrin reaction, which is commonly used for amino acid quantification and can be adapted for indirect protein determination. In our method, algal biomass is first incubated in 10 M NaOH to release potential interfering compounds, such as free amino acids and pigments, into the supernatant. This supernatant is reacted with ninhydrin to establish a background non-protein signal. The same solution is then subjected to thermal hydrolysis (120 °C, 20 min) to break down proteins into free amino acids, which are quantified via a second ninhydrin reaction. A calibration curve, generated from hydrolyzed bovine serum albumin (BSA) treated under identical conditions, enables protein determination. We applied this method to measure the protein content of, C. sorokiniana, comparing the results with those from the Kjeldahl method and free and total amino acid profiling. Our findings demonstrate that the proposed ninhydrin-based approach is a feasible and reliable alternative for algal protein quantification.
准确测量藻类生物量中的蛋白质含量对于评估其在食品、饲料和生物燃料应用中的适用性至关重要。传统的标准，凯氏定氮法，依赖于一个既依赖于物种又依赖于生长条件的氮到蛋白质的转换因子，引入了潜在的可变性。此外，许多藻类物种的坚固细胞壁阻碍了有效的蛋白质提取直接测量，导致实验室结果不一致。蛋白质含量的很大一部分也可能位于细胞壁本身。为了解决这些限制，我们评估了一种基于茚三酮反应的替代方法，该方法通常用于氨基酸定量，也可用于间接测定蛋白质。在我们的方法中，藻类生物量首先在10 M NaOH中孵育，以释放潜在的干扰化合物，如游离氨基酸和色素，到上清中。该上清与茚三酮反应以建立背景非蛋白信号。然后将相同的溶液进行热水解（120°C， 20分钟）以将蛋白质分解为游离氨基酸，通过第二次茚三酮反应定量。由在相同条件下处理的水解牛血清白蛋白（BSA）生成的校准曲线使蛋白质测定成为可能。应用该方法测定了sorokiniana的蛋白质含量，并与凯氏定氮法、游离氨基酸和总氨基酸谱法进行了比较。我们的研究结果表明，提出的基于茚三酮的方法是一种可行和可靠的藻类蛋白质定量替代方法。
{"title":"No cell wall disruption needed: Algal protein content quantification via alkaline hydrolysis and ninhydrin reaction","authors":"Hamideh Abdolrahmani , Amir Amiri-Sadeghan , Maryam Seyyedi , Leila Zarandi Miandoab","doi":"10.1016/j.algal.2025.104511","DOIUrl":"10.1016/j.algal.2025.104511","url":null,"abstract":"<div><div>Accurate measurement of protein content in algal biomass is essential for assessing its suitability for food, feed, and biofuel applications. The conventional standard, the Kjeldahl method, relies on a nitrogen-to-protein conversion factor that is both species- and growth-condition-dependent, introducing potential variability. Furthermore, the robust cell walls of many algal species hinder efficient protein extraction for direct measurement, leading to inconsistent results across laboratories. A significant portion of the protein content may also be located within the cell wall itself. To address these limitations, we evaluated an alternative approach based on the ninhydrin reaction, which is commonly used for amino acid quantification and can be adapted for indirect protein determination. In our method, algal biomass is first incubated in 10 M NaOH to release potential interfering compounds, such as free amino acids and pigments, into the supernatant. This supernatant is reacted with ninhydrin to establish a background non-protein signal. The same solution is then subjected to thermal hydrolysis (120 °C, 20 min) to break down proteins into free amino acids, which are quantified via a second ninhydrin reaction. A calibration curve, generated from hydrolyzed bovine serum albumin (BSA) treated under identical conditions, enables protein determination. We applied this method to measure the protein content of, <em>C. sorokiniana</em>, comparing the results with those from the Kjeldahl method and free and total amino acid profiling. Our findings demonstrate that the proposed ninhydrin-based approach is a feasible and reliable alternative for algal protein quantification.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"94 ","pages":"Article 104511"},"PeriodicalIF":4.5,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146074062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-06DOI: 10.1016/j.algal.2025.104515
Yaoyao Wang , Xianbin Zhu , Han Wang , Kexin Wei , Menghan Cao
Aquaculture effluents are major sources of nutrient and organic pollution, making their treatment a critical research priority. This study evaluated the performance of a natural in-situ algae–bacteria consortia in treating two types of aquaculture wastewater (soft-shelled turtle effluent and aquacultural sludge wastewater). After 7 days, the consortia achieved high removal efficiencies in turtle effluent, 93.5 % for ammonium nitrogen (NH4+-N), 82.6 % for total nitrogen (TN), and 70.6 % for chemical oxygen demand (COD). In sludge wastewater, removal efficiencies reached 77.1 % for NH4+-N, 87.1 % for TN, 91.7 % for COD, and 89.0 % for total phosphorus (TP), outperforming non-algal controls by 25–45 %. Microbial community analyses revealed a shift toward Chlorella dominant algal populations and a transition from fermentative bacterial taxa (e.g. Clostridium) to aerobic groups such as Pseudomonas and Acinetobacter, supporting enhanced nutrient transformations. Redundancy analysis (RDA) and canonical correspondence analysis (CCA) showed that nutrient variables explained over 58 % of community variation, with NH4+-N and TP strongly correlated with Clostridium and Ruminiclostridium, and TN and NO3−-N associated with Chloroplast, Mitochondria. Mantel tests and random forest analyses identified Chloroplast, Clostridium, Ruminiclostridium, and norank_o_Veillonellales-Selenomonadales as robust biomarkers. These findings demonstrate that algae–bacteria consortia effectively reduce pollutants in aquaculture effluents through synergistic restructuring of microbial communities, offering a scalable strategy for sustainable wastewater management.
{"title":"Identifying bacterial biomarkers in algae–bacteria consortia: Insights from multivariate analyses of nutrient removal","authors":"Yaoyao Wang , Xianbin Zhu , Han Wang , Kexin Wei , Menghan Cao","doi":"10.1016/j.algal.2025.104515","DOIUrl":"10.1016/j.algal.2025.104515","url":null,"abstract":"<div><div>Aquaculture effluents are major sources of nutrient and organic pollution, making their treatment a critical research priority. This study evaluated the performance of a natural in-situ algae–bacteria consortia in treating two types of aquaculture wastewater (soft-shelled turtle effluent and aquacultural sludge wastewater). After 7 days, the consortia achieved high removal efficiencies in turtle effluent, 93.5 % for ammonium nitrogen (NH<sub>4</sub><sup>+</sup>-N), 82.6 % for total nitrogen (TN), and 70.6 % for chemical oxygen demand (COD). In sludge wastewater, removal efficiencies reached 77.1 % for NH<sub>4</sub><sup>+</sup>-N, 87.1 % for TN, 91.7 % for COD, and 89.0 % for total phosphorus (TP), outperforming non-algal controls by 25–45 %. Microbial community analyses revealed a shift toward <em>Chlorella</em> dominant algal populations and a transition from fermentative bacterial taxa (e.g. <em>Clostridium</em>) to aerobic groups such as <em>Pseudomonas</em> and <em>Acinetobacter</em>, supporting enhanced nutrient transformations. Redundancy analysis (RDA) and canonical correspondence analysis (CCA) showed that nutrient variables explained over 58 % of community variation, with NH<sub>4</sub><sup>+</sup>-N and TP strongly correlated with <em>Clostridium</em> and <em>Ruminiclostridium</em>, and TN and NO<sub>3</sub><sup>−</sup>-N associated with <em>Chloroplast</em>, <em>Mitochondria</em>. Mantel tests and random forest analyses identified <em>Chloroplast</em>, <em>Clostridium</em>, <em>Ruminiclostridium</em>, and <em>norank_o_Veillonellales-Selenomonadales</em> as robust biomarkers. These findings demonstrate that algae–bacteria consortia effectively reduce pollutants in aquaculture effluents through synergistic restructuring of microbial communities, offering a scalable strategy for sustainable wastewater management.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"94 ","pages":"Article 104515"},"PeriodicalIF":4.5,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号