Algal Research-Biomass Biofuels and Bioproducts最新文献

{"title":"Combined analysis of reactive oxygen species and symbiotic bacteria profiles reveals their potential effects on the sorus development of Saccharina japonica","authors":"Jing Zhang ,&nbsp;Fuli Liu ,&nbsp;Yining Chen ,&nbsp;Ruibin Sun ,&nbsp;Xu Gao","doi":"10.1016/j.algal.2025.104122","DOIUrl":"10.1016/j.algal.2025.104122","url":null,"abstract":"<div><div>Symbiotic bacteria are highly associated with the growth and development of seaweeds, primarily due to their ability to secrete bioactive metabolites. Reactive oxygen species (ROS) play a critical role in regulating growth and development in <em>S. japonica</em>, but the interactions between symbiotic bacterial communities and ROS on the vegetative and sorus areas of <em>S. japonica</em> remain unclear. In this study, the content of ROS (hydrogen peroxide), malondialdehyde (MDA) and NADPH in the vegetative and sorus areas of <em>S. japonica</em> were determined. Results revealed significantly higher concentration of ROS, MDA, and NADPH in the sorus area, indicating an elevated oxidative environment in reproductive areas. Using 16S rRNA gene amplicon sequencing, both epiphytic and endophytic bacterial communities were analyzed. Comparative analysis revealed pronounced divergence in endophytic bacterial diversity and composition between vegetative and sorus areas. Notably, the core genera norank_f_Rhizobiaceae exhibited strong positive correlations with NADPH accumulation, suggesting their potential role in both oxidative process modulation and holobiont functional stability of <em>S. japonica</em>. These findings suggest potential interactions between symbiotic bacteria and ROS metabolism during <em>S. japonica</em> sorus development, offering new perspectives for understanding and potentially improving seaweeds cultivation strategies to enhance stress resilience.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"91 ","pages":"Article 104122"},"PeriodicalIF":4.6,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144243227","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}

{"title":"Effect of nitrogen limitation and carbon sources on hydrogen and lipid production by Chlorella pyrenoidosa","authors":"Weiqing Zhang ,&nbsp;Shibin Dong ,&nbsp;Litao Zhang ,&nbsp;Wenjie Yu ,&nbsp;Ling Li ,&nbsp;Anatoly Tsygankov ,&nbsp;Jianguo Liu","doi":"10.1016/j.algal.2025.104128","DOIUrl":"10.1016/j.algal.2025.104128","url":null,"abstract":"<div><div>Biofuel (including H₂ and lipids) from green algae is an attractive way to produce renewable energy. Under nitrogen-limitation, <em>Chlorella pyrenoidosa</em> produced both H₂ and lipids. In this study, the effects of nitrogen and carbon sources on the growth and the co-production of H₂ and lipids in <em>C. pyrenoidosa</em> were examined, and the regulatory mechanisms including photosynthetic electron transport, NADPH production and acetyl-CoA metabolism were investigated. The peak H₂ yield (241.42 mL L⁻¹) was found in 5 % nitrogen concentration (0.35 mM NH₄Cl) treatment, with the total lipid content being 45.0 % of dry weight. Nitrogen-limitation decreased PSII activity, inhibiting photosynthetic O₂ evolution, and thereby creating favorable anaerobic conditions for enhanced H₂ production. Excess energy in the photosynthetic electron transport chain prompted hydrogenase to consume surplus electrons as the terminal electron acceptor and produce H₂. Furthermore, nitrogen-limitation induced overreduction on the PSII acceptor side, resulting in the accumulation of NADPH, which provided reducing power for fatty acids synthesis. The addition of acetic acid enhanced the growth, H₂ production, and lipid accumulation in <em>C. pyrenoidosa</em>, with a recommended concentration of 2 mL L⁻¹. It was proposed that acetic acid inhibited photosynthesis, subsequently decreasing photosynthetic O₂ evolution. Additionally, acetic acid was converted into acetyl-CoA to provide the precursor for fatty acid synthesis, and it also promoted the generation of NADH, which provided the reducing power required for both fatty acid synthesis and H₂ production. These results highlight the positive roles of nitrogen limitation and acetic acid in enhancing H₂ and lipid production in <em>C. pyrenoidosa</em> and provide a basis for improving <em>Chlorella</em>'s energy production efficiency through artificial regulation.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"91 ","pages":"Article 104128"},"PeriodicalIF":4.6,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144253661","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}

{"title":"Algae and cyanobacteria-mediated biosynthesis of metal/metal oxide nanoparticles and their potential applications in food packaging","authors":"Sahil Tahiliani ,&nbsp;Nishtha Lukhmana ,&nbsp;Sumit Chhangani ,&nbsp;Shiv Dutt Purohit ,&nbsp;Sauraj ,&nbsp;Ruchir Priyadarshi","doi":"10.1016/j.algal.2025.104124","DOIUrl":"10.1016/j.algal.2025.104124","url":null,"abstract":"<div><div>With a growing global emphasis on sustainability and eco-friendly practices, biosynthesis of nanoparticles has emerged as a pioneering alternative to conventional chemical-based synthesis methods. In this context, algae and cyanobacteria have been used as renewable biomass resources, providing an economically viable, environmentally benign, and easily scalable platform for nanoparticle production. Algae and cyanobacteria extracts comprise various functional macromolecules and metabolites that not only reduce the metal salts to form nanoparticles but also form a surface capping, aiding their stabilization and imparting additional functionality. Algae and cyanobacteria have successfully mediated the synthesis of diverse nanoparticles, especially metal and metal oxides, demonstrating exceptional functional and biological properties. Remarkably, these biosynthesized nanoparticles often rival or even surpass the performance attributes of chemically synthesized counterparts, underscoring their potential in various industrial applications. One particularly promising application lies in the food packaging sector, where nanoparticles serve as multifunctional fillers in biopolymer matrices, significantly enhancing film characteristics. Conventional chemically synthesized nanoparticles, however, have raised critical safety and environmental concerns, intensifying the demand for greener alternatives. This comprehensive review uniquely addresses these challenges by focusing explicitly on algae and cyanobacteria-mediated nanoparticle synthesis and meticulously discusses their prospective applications in food packaging. These biosynthesized surface functionalized nanoparticles not only address safety concerns by displaying enhanced biocompatibility and reduced cytotoxicity but also can provide additional functional properties like antioxidant activity to the food packaging materials, emphasizing their potential to extend food shelf-life and ensure consumer safety.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"90 ","pages":"Article 104124"},"PeriodicalIF":4.6,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144270534","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}

{"title":"Mannuronan C5-epimerases for tailored seaweed alginate modification","authors":"Jan Muschiol ,&nbsp;Morten Schiøtt ,&nbsp;Maria Dalgaard Mikkelsen ,&nbsp;Anne S. Meyer","doi":"10.1016/j.algal.2025.104126","DOIUrl":"10.1016/j.algal.2025.104126","url":null,"abstract":"<div><div>Alginate is a linear polysaccharide composed of (1 → 4)-linked β-D-mannuronate (M) and its C5-epimer α-L-guluronate (G) distributed in blocks of mainly MM-, GG- or alternating MG-residues. Alginate is found in the cell walls of brown macroalgae (seaweed, class Phaeophyceae), but is also produced by certain bacterial species within the <em>Pseudomonas</em> and <em>Azotobacter</em> genera. Due to its hydrocolloid and gelation properties, alginate is widely used in foods and healthcare products, e.g. for moisture control in band-aids. The gelation properties of alginate are determined by the G-residues, i.e. the so-called GG blocks, through interactions with cations, particularly Ca²⁺. In brown macroalgae alginate is first produced as poly-M molecules (mannuronan). During cell wall adaptation and maturation, the M-residues are modified by mannuronan C5-epimerases, EC 5.1.3.37, which convert some of the M-residues to G-residues by catalyzing the “flipping” of the C5 group. While the G:M ratio varies by macroalgal species and geographic location, mature alginates usually contain more G-residues and have better gelation properties, whereas brown macroalgae cultivated in calm water, including those now farmed in the Northern Hemisphere, typically have a low G:M ratio. The interest in using microbial mannuronan C5-epimerases to improve the gelation properties and thus increase the application value of alginate from cultivated brown macroalgae is therefore increasing. The structure and catalytic properties of different microbial mannuronan C5-epimerases, especially those of <em>Azotobacter vinelandii</em>, have been studied for decades. Recently, extensive product profiling and recombinant production of macroalgal C5-epimerases have also been reported. In this review we present detailed descriptions of mannuronan C5-epimerases, including the microbial, macroalgal, and mutated enzymes characterized so far, focusing on reaction mechanisms, enzyme types, assays, modular structure-function properties, and not least reaction product composition. The findings provide an overview of how minor changes can shape enzyme function and alginate composition.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"90 ","pages":"Article 104126"},"PeriodicalIF":4.6,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144262162","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}

{"title":"Reversible electropermeabilization of Auxenochlorella protothecoides microalgae: tracking mass transfer and membrane resealing dynamics induced by pulsed electric fields","authors":"Byron Perez ,&nbsp;Nicola Weber ,&nbsp;Iris Haberkorn ,&nbsp;Alexander Mathys","doi":"10.1016/j.algal.2025.104125","DOIUrl":"10.1016/j.algal.2025.104125","url":null,"abstract":"<div><div>Pulsed Electric Field (PEF) treatment is an emerging technology that enhances mass transfer by inducing cell permeabilization, offering great potential in microalgae bioprocessing. While irreversible permeabilization for extraction has been extensively studied, reversible permeabilization remains largely unexplored for most microalgae species, thus limiting its application in processes requiring viable cells, such as cyclic extraction, gene delivery, and cell fortification. This study investigated how electric field strength and split pulse configuration, either a single long pulse or multiple shorter pulses, affect the reversible electropermeabilization of <em>Auxenochlorella protothecoides</em>. The uptake of the cell membrane-impermeable stain Sytox Green™ was used to assess cell permeabilization, while protein extraction served as a mass transfer indicator. Results showed that a split pulse configuration (2 × 50 μs or 5 × 20 μs pulses at 15 kV cm⁻¹) increased the relative fluorescence intensity fivefold compared with a single long pulse, with only a 12 % increase in energy input. The split pulse approach kept the cells permeable for over 10 min, enabling 38 % more protein extraction with 41 % less energy than a single pulse at 20 kV cm⁻¹, but this higher degree of permeabilization compromised cell viability, inactivating around 70 % of the cells and delaying regrowth during the first 48 h, thereby hindering suitability for live-cell applications. For the first time, the resistance of <em>A. protothecoides</em> to high electric fields has been investigated, e.g., with a single pulse of 15 kV cm⁻¹ permeabilizing the cells for at least 5 min while maintaining good resealing and survival rates comparable to the untreated control. These findings offer valuable insights into maximizing reversible permeabilization, mass transfer, and cell survival in microalgae while minimizing energy consumption in PEF processing.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"90 ","pages":"Article 104125"},"PeriodicalIF":4.6,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144270533","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}

{"title":"Treatment of nitrogen and phosphorus for four types of aquaculture wastewater by using nitrogen- and phosphorus-starved Chromochloris zofingiensis","authors":"Jiayi Li ,&nbsp;Jiawei Song ,&nbsp;Lingjiao Bu ,&nbsp;Lixin Jiao ,&nbsp;Yanmei Peng ,&nbsp;Bowen Miao ,&nbsp;Yingjie Huo ,&nbsp;Tong Li ,&nbsp;Yueqiang Guan ,&nbsp;Zhao Zhang","doi":"10.1016/j.algal.2025.104127","DOIUrl":"10.1016/j.algal.2025.104127","url":null,"abstract":"<div><div>With the gradual increase in the degree of intensification of aquaculture industry, large amounts of aquaculture wastewater (AW) with excess nitrogen (N) and phosphorus (P) are generated. In this study, the treatment feasibility of four types of AW, including the Chinese soft-shelled turtle (<em>Pelodiscus sinensis</em>) AW, the Largemouth bass (<em>Micropterus salmoides</em>) AW, the Pacific white shrimp (<em>Litopenaeus vannamei</em>) AW,<!--> <!-->and the Hybrid sturgeon (<em>Acipenser baerii</em> ♂ × <em>Acipenser schrenckii</em> ♀) AW by N- and P-starved <em>Chromochloris zofingiensis</em> was assessed. The total N concentration ranged from 14.63 mg L⁻¹ to 63.54 mg L⁻¹, while the total P concentration ranged from 0.36 mg L⁻¹ to 5.78 mg L⁻¹. The removal efficiencies of total N and total P from four types of AW ranged from 79.08 % to 97.54 % and 38.80 % to 83.02 %, respectively. In addition, <em>C. zofingiensis</em> achieved the highest protein content in <em>M. salmoides</em> AW on day 6, reaching 0.46 g g⁻¹. Where it achieved the highest fatty acids and astaxanthin content in Hybrid sturgeon AW, reaching 0.59 g g⁻¹ and 0.95 mg g⁻¹, respectively. In addition, <em>C. zofingiensis</em> exhibited a health-promoting amino acid and fatty acid composition for aquaculture animals after treatment with the four types of AW. Therefore, a recycling scheme AW treatment was proposed. Overall, this study demonstrated the feasibility of using N- and P-starved <em>C. zofingiensis</em> to convert N and P from AW into nutrients, which can be applied as aquafeed additives.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"90 ","pages":"Article 104127"},"PeriodicalIF":4.6,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144221949","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}

{"title":"Online multiparameter sensor for microalgae cultivation: prediction of nitrate, biomass and pigment concentrations","authors":"Yashika Sorathia ,&nbsp;Ana Pereira ,&nbsp;Aravind Krishnaswamy Rangarajan ,&nbsp;Timo van der Spek ,&nbsp;Jeroen H. de Vree ,&nbsp;Lucie Lourmière ,&nbsp;Narcis Ferrer-Ledo ,&nbsp;Joris van Nieuwstadt ,&nbsp;Marta Sá","doi":"10.1016/j.algal.2025.104123","DOIUrl":"10.1016/j.algal.2025.104123","url":null,"abstract":"<div><div>Industrial microalgae production is widely recognized as a sustainable and promising method for generating nutraceuticals, biofertilizers, food ingredients, and feed. However, the lack of automated process control in current industrial facilities is a significant limitation, primarily due to the absence of sensors capable of measuring the growth medium's chemical composition and biomass. In this study, a novel method for simultaneously measuring several critical process parameters, including nitrate, various pigments, and biomass is presented. The approach is based on optical transmission and machine learning-based chemometrics and is reagent-free and non-invasive, making it ideal for development into an automated online device.</div><div>Measurements of optical spectra and chemical concentrations were conducted for two microalgae species, <em>Arthrospira platensis</em> and <em>Tetradesmus obliquus</em>, across different levels of biomass and nitrate. Through Partial Least Squares analysis of the data, biomass concentrations can be inferred in a range up to 8 g.L⁻¹ (root mean square error (RMSE) of 0.55 g.L⁻¹ and R² 0.75 for <em>A. platensis</em>, and RMSE of 0.52 g.L⁻¹ and R² 0.88 for <em>T. obliquus</em>), using the same model for the different species (RMSE of 0.72 g.L⁻¹ and R² 0.74). Nitrate concentrations can be estimated in a range between 0 and 800 mg.L⁻¹ (RMSE of 41.70 mg.L⁻¹, R² of 0.82) in the presence of biomass and without the need to discriminate between the microalgae tested. For <em>T. obliquus</em>, total chlorophyl (from 2 to 18 mg.g⁻¹ biomass, RMSE 1.24 mg.g⁻¹ and R² of 0.71) and carotenoids content (from 1 to 12 mg.g⁻¹ biomass, RMSE 1.12 mg.g⁻¹ and R² of 0.59) can be estimated directly during the cultivation.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"90 ","pages":"Article 104123"},"PeriodicalIF":4.6,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144203997","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}

{"title":"Digestion and bioconversion of microalgal galactolipids by direct action of lipolytic enzymes on Chlamydomonas reinhardtii biomass","authors":"Beatriz Rodrigues Fachini ,&nbsp;Cassy Gérard ,&nbsp;Achille Marchand ,&nbsp;Olivier Bornet ,&nbsp;Valérie Gros ,&nbsp;Claire Vigor ,&nbsp;Camille Oger ,&nbsp;Guillaume Reversat ,&nbsp;Thierry Durand ,&nbsp;Goetz Parsiegla ,&nbsp;Brigitte Gontero ,&nbsp;Hélène Launay ,&nbsp;Frédéric Carrière","doi":"10.1016/j.algal.2025.104121","DOIUrl":"10.1016/j.algal.2025.104121","url":null,"abstract":"<div><div>Microalgae, like <em>Chlamydomonas reinhardtii</em>, are rich in polyunsaturated fatty acids (PUFAs) bound to galactolipids. Their bioaccessibility to digestive enzymes in whole cells was tested using guinea pig pancreatic lipase-related protein 2 (GPLRP2) and <em>Fusarium solani</em> cutinase, showing high lipolysis levels with total galactolipid fatty acid release of 93 % with GPLRP2. These enzymes also converted galactolipid fatty acids into ethyl esters with ethanol, what could facilitate PUFA recovery from microalgal biomass. <em>In vitro</em> digestion studies mimicking gastric and intestinal conditions revealed that human pancreatic galactolipases release α-linolenic acid (ALA) as the main free fatty acid (≥35 %). NMR analysis indicated PUFA oxidation when microalgal endogenous enzymes were not inactivated before digestion. ALA oxidation into phytoprostanes occurred, especially after lipolysis. Thus, <em>C. reinhardtii</em> galactolipids are bioaccessible to digestive enzymes, making them a valuable PUFA source, provided oxidation is controlled.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"90 ","pages":"Article 104121"},"PeriodicalIF":4.6,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144203998","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}

{"title":"Metabolomic changes and enhanced digestibility with algae (Spirulina platensis) derived polysaccharides supplementation in broilers","authors":"Padsakorn Pootthachaya ,&nbsp;Sawitree Wongtangtintharn ,&nbsp;Warin Puangsap ,&nbsp;Nisakon Pintaphrom ,&nbsp;Theeraphat Srikha ,&nbsp;Anusorn Cherdthong ,&nbsp;Bundit Yuangsoi ,&nbsp;Bundit Tengjaroensakul ,&nbsp;Iwasaki Hironori","doi":"10.1016/j.algal.2025.104112","DOIUrl":"10.1016/j.algal.2025.104112","url":null,"abstract":"<div><div>The objective of this study was to investigate the effects of algae (<em>Spirulina platensis</em>)-derived polysaccharides (ADPs) on performance, digestibility, intestinal histomorphology, digestive enzyme activities, and metabolomic profiles in broiler chickens. A total of 320 one-day-old Ross 308 mixed-sex broilers were randomly allocated to 5 dietary treatments comprising 0 (Control), 1500, 3000, 4500, and 6000 mg ADPs/kg in a completely randomized design. Each treatment included 4 replications, with 16 birds per replicate. The feeding trial lasted 42 days, encompassing starter (1–10 days), grower (11–24 days), and finisher (25–42 days) phases. The results demonstrated that dietary ADPs supplementation at 3000 mg/kg significantly enhanced (<em>P</em> &lt; 0.05) body weight gain and improved feed conversion ratio during the overall period (1–42 days). In addition, supplementation with 1500–4500 mg/kg ADPs significantly improved (<em>P</em> &lt; 0.05) <em>in vitro</em> crude protein digestibility (period 2) and apparent metabolizable energy (periods 2 and 3). Meanwhile, <em>in vivo</em> digestibility was also enhanced by ADPs supplementation, with significant improvements (<em>P</em> &lt; 0.05) in dry matter (period 2) and crude protein (periods 2 and 3) digestibility. Histomorphological analysis revealed that ADPs supplementation at 1500–6000 mg/kg significantly increased (<em>P</em> &lt; 0.05) villus height, villus width, villus height-to-crypt depth ratio, and villus surface area throughout the small intestine. Additionally, digestive enzyme activities, including amylase, lipase, and protease, were significantly elevated (<em>P</em> &lt; 0.05) in broilers supplemented 3000–4500 mg/kg ADPs. Metabolomic analysis identified significant alterations in liver and breast muscle metabolites, with 194 differentially expressed metabolites in the liver and 134 in the breast, primarily associated with amino acid metabolism pathways. In the liver, the most affected pathways included lysine degradation, glycine-serine-threonine metabolism, and arginine biosynthesis. In the breast muscle, key pathways included phenylalanine-tyrosine-tryptophan biosynthesis, glycine-serine-threonine metabolism, and valine-leucine-isoleucine biosynthesis. Regarding principal component analysis demonstrated distinct clustering between control and ADPs-treated groups, indicating notable metabolic shifts. These findings suggest that the supplementation of ADPs from <em>S. platensis</em> enhances nutrient digestibility, intestinal morphology, digestive enzyme activity, and key metabolic pathways, ultimately supporting broiler growth performance. Based on the comprehensive findings of this study, dietary supplementation with ADPs at 3000 mg/kg is recommended as the optimal level.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"90 ","pages":"Article 104112"},"PeriodicalIF":4.6,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144195585","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}

{"title":"Exopolysaccharide from Haematococcus pluvialis enhances photosynthesis, biomass and astaxanthin accumulation","authors":"Feng Chen ,&nbsp;Litao Zhang ,&nbsp;Shuju Guo ,&nbsp;Wenjie Yu ,&nbsp;Jing Li ,&nbsp;Jianguo Liu","doi":"10.1016/j.algal.2025.104120","DOIUrl":"10.1016/j.algal.2025.104120","url":null,"abstract":"<div><div><em>Haematococcus pluvialis</em> is recognized as the prime biological source of natural astaxanthin. However, the physiological and metabolic effects of <em>H. pluvialis</em> exopolysaccharide (HPEPS), which is derived from both secretion and cell wall dissolution during cell growth and transformation, remain unclear. This study systematically elucidated the regulatory effects of HPEPS on astaxanthin biosynthesis in <em>H. pluvialis</em> through physiological and metabolomics analyses, and preliminary characterization of its structure was also performed. Under high light stress, exogenous supplementation of 220 mg/L HPEPS induced cell division arrest and increased cell diameter to 1.25-fold of the original size, thereby providing space for biomass and astaxanthin accumulation. Concurrently, it enhanced photosynthetic efficiency and maintained energy metabolic homeostasis, leading to 1.36-fold, 1.82-fold, and 2.6-fold increases in biomass, astaxanthin yield, and astaxanthin content, respectively. Integrated metabolomics analysis revealed that HPEPS activation enhances carbon assimilation, photorespiration, and glyoxylate cycle pathways to enhance precursor supply for astaxanthin biosynthesis. Structural elucidation further identified HPEPS as a heteropolysaccharide primarily containing guluronic acid (GulA, 37.4 %), galactose (18.9 %), and arabinose (12.0 %). Notably, this work reports the first detection of GulA in microalgal exopolysaccharides. Overall, this study not only provides a theoretical basis for elucidating the structural composition and physiological role of HPEPS, but also develops a new approach to optimize the production of natural astaxanthin.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"90 ","pages":"Article 104120"},"PeriodicalIF":4.6,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144213131","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}