Algal Research-Biomass Biofuels and Bioproducts最新文献

{"title":"Regulatory role of microcystin in the response of microcystin-producing cyanobacteria to elevated CO2: Insights from metabolic profiling","authors":"Jingjie Ma ,&nbsp;Peifang Wang ,&nbsp;Xun Wang ,&nbsp;Bin Hu ,&nbsp;Jin Qian","doi":"10.1016/j.algal.2024.103760","DOIUrl":"10.1016/j.algal.2024.103760","url":null,"abstract":"<div><div>The regulatory role of microcystin in the response of microcystin-producing cyanobacteria to elevated CO₂ remains poorly understood. To address this gap, this study compared the responses of wild-type toxic <em>Microcystis</em> PCC 7806 and its <em>mcy</em>B-knockout mutant to elevated CO₂ using metabolomic profiling under nitrogen (N)-rich and N-poor conditions. Under N-poor conditions, elevated CO₂ promoted carbohydrate synthesis and tricarboxylic acid cycle in both strains, without affecting their growth. Under N-rich conditions, both strains exhibited increased biomass with rising CO₂ levels, attributed to enhanced carbohydrate synthesis, tricarboxylic acid cycle, glutamate-glutamine cycle, purine synthesis, and arginine synthesis. However, compared to the mutant, the proliferation of wild-type toxic <em>Microcystis</em> was less stimulated by elevated CO_2. The difference was associated with its reduced activity in the pentose phosphate pathway, likely linked to microcystin synthesis. Besides, the difference was related to higher utilization of glutamate, arginine, and aspartate due to increased microcystin production, indicating the regulatory role of microcystin in the response of microcystin-producing <em>cyanobacteria</em> to elevated CO₂. Importantly, elevated CO₂ could enhance microcystin synthesis by promoting the production of carbon backbones (malonyl CoA), amino acids (including arginine, glutamate and aspartate) and methyl donors (S-adenosylmethionine) of the wild-type toxic <em>Microcystis</em> PCC 7806. Notably, sufficient nitrogen sources were required for increased amino acid and methyl donors synthesis at high CO₂ concentration. The discovery revealed underlying mechanisms behind the potential for elevated CO₂ levels to increase toxicity risk associated with <em>Microcystis</em> blooms.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"84 ","pages":"Article 103760"},"PeriodicalIF":4.6,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553889","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":"Chromosome-level genome assembly of the cosmopolitan diatom Skeletonema costatum provides insights into ecological adaptation","authors":"Shuya Liu ,&nbsp;Nansheng Chen","doi":"10.1016/j.algal.2024.103761","DOIUrl":"10.1016/j.algal.2024.103761","url":null,"abstract":"<div><div>The cosmopolitan diatom species <em>Skeletonema costatum</em> is an ecologically important dominant phytoplankton frequently found in the coastal estuarine and marine waters, and often causes harmful algae blooms. Despite of its critical ecological importance, chromosome-level genome assemble is still unavailable, hindering in-depth understanding of their evolution and environmental adaption. Here, we report a chromosome-level genome assembly for the marine diatom species <em>S. costatum</em>. The assembled genome size was 136.49 Mb, with a contig N50 of 302 Kb and 95.30 % of the reads anchored into 23 pseudo-chromosomes with a scaffold N50 of 6.19 Mb. A total of 28,321 protein-coding genes were predicted, with 86.03 % being functional annotated. The BUSCO assessment of genome assembly and genome annotation were both above 90 %. Phylogenetic analysis showed the expected topology, with <em>S. costatum</em> and its closely related species <em>S. marinoi</em> diverged from their common ancestor around 22.6 million years ago. The genome size of <em>S. costatum</em> is comparatively larger than those of its closely related diatoms, due mostly to its higher transposable element contents and larger number of proteincoding genes. Collinearity analysis revealed strong collinearity between <em>S. costatum</em> and other <em>Skeletonema</em> with most chromosomes showing clear one-to-one correspondences. A larger family of nine copies of the cryptochrome genes that function as blue light photoreceptors were identified in <em>S. costatum</em>, which could contribute its ecological success. The availability of the high-quality chromosome-level genome assembly for <em>S. costatum</em> represents a valuable resource that may facilitate comparative genomics for revealing important ecological clues and gene families, and future genetics and environmental studies among <em>Skeletonema</em> species.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"84 ","pages":"Article 103761"},"PeriodicalIF":4.6,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532386","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":"Advancing plastics bio-upcycling with photosynthetic microorganisms using bioengineering and bioconversion strategies","authors":"Hazlam Shamin Ahmad Shaberi ,&nbsp;Hamidun Bunawan ,&nbsp;Sean Craig ,&nbsp;Samantha J. Bryan ,&nbsp;Ahmad Bazli Ramzi","doi":"10.1016/j.algal.2024.103755","DOIUrl":"10.1016/j.algal.2024.103755","url":null,"abstract":"<div><div>Biotechnological interventions have been increasingly adopted for addressing the persistence and recalcitrance of fossil fuel-derived plastic waste. Bioremediation through microbial and enzymatic degradation offers promising solutions, yet economic and scalability challenges persist, especially for addressing plastic waste accumulation in aquatic ecosystems. Despite recent advancements in plastic bioconversion and bio-upcycling using recombinant enzymes and microbes, current genetic and biological engineering platforms mainly employed heterotrophic chassis such as <em>Escherichia coli</em> and <em>Pseudomonas putida</em>, that are not suitable for direct cultivation using wastewater sources. Photosynthetic microorganisms like cyanobacteria and microalgae offer a sustainable alternative to the heterotrophic counterparts, in not only converting wastewater and CO₂ as carbon and energy sources but also bring about carbon-neutral bioconversion potentials. Therefore, this review explores bioengineering strategies required to develop and harness the capabilities of cyanobacteria and microalgae for plastic biomineralisation. Pathway engineering in selected chassis is highlighted by detailing the metabolic pathways involved in plastic degradation where the application of growth-coupled genome editing and advanced biotechnological tools is further discussed. By integrating biofoundry-driven bioengineering strategies with growth-coupled selection, microalgal strain development can be accelerated towards achieving high substrate-to-product yields thus promoting carbon-neutral biorefinery and plastic bioconversion approaches.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"84 ","pages":"Article 103755"},"PeriodicalIF":4.6,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532387","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":"Sargassum hornery fucoidan oligosaccharide: Purification, characterization, and antioxidant effects targeting the MAPK and KEAP1-NRF2 signaling pathways","authors":"Shengyu Fan ,&nbsp;Ying Xu ,&nbsp;Lei Wang ,&nbsp;Xin Gao ,&nbsp;Soon-Mi Shim ,&nbsp;Xiaoting Fu","doi":"10.1016/j.algal.2024.103756","DOIUrl":"10.1016/j.algal.2024.103756","url":null,"abstract":"<div><div>The current research looked into the inhibitory effect of a purified component of <em>Sargassum hornery</em> fucoidan oligosaccharide (F2) with a sulfate content of 16.35 %, which showed substantial protective effects on H₂O₂-induced oxidative damage in RAW 264.7 cells and zebrafish. The chemical and structural characteristics were examined by GC, FTIR, MS, and NMR spectroscopy, revealing that F2 was composed of not only a mixed oligosaccharide with 1–4 degrees of polymerization but also had a main chain consisting of (1 → 3) linked α-L-Fuc<em>p</em> and (1 → 3,4) linked α-L-Fuc<em>p</em>, sulfated groups mainly at C2 position. It was found that F2 could activate the MAPK and Keap1-Nrf2 signaling pathways through the dissociation of the Keap1-Nrf2 complex in RAW 264.7 cells. Then Nrf2 entered the cell and bound to the antioxidant response element (ARE), resulting in activating the expression of downstream antioxidant genes. F2 was also found to have a strong protective effect on oxidative stress in zebrafish induced by H₂O₂, which can reduce the heart rate of zebrafish and prevent the generation of intracellular ROS and cell death. Therefore, <em>S. hornery</em> fucoidan oligosaccharide (F2) could be a potential ingredient for functional foods, cosmetics, and pharmaceuticals because of its antioxidant activity.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"84 ","pages":"Article 103756"},"PeriodicalIF":4.6,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532508","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":"Pilot plant cultivation of microalga Dictyosphaerium chlorelloides with night illumination from LEDs sources","authors":"Jana Kvíderová ,&nbsp;David Kubáč ,&nbsp;Jaromír Lukavský","doi":"10.1016/j.algal.2024.103759","DOIUrl":"10.1016/j.algal.2024.103759","url":null,"abstract":"<div><div>Illumination during the night with white LEDs increased the growth of the microalga <em>Dictyosphaerium chlorelloides</em> strain CCALA 330 on a thin-film platform unit (150 L volume, 12 m² area) approximately 2.5× in comparison to the platform illuminated only by the Sun. The mean PAR intensity on the Sun-illuminated unit was 71 μmol m⁻² s⁻¹, on the Sun + LEDs unit 549 μmol m⁻² s⁻¹, the mean temperatures were 15 °C and 20.1 °C. On the Sun unit the algae grew to a maximum of 15 g L⁻¹ dry weight in 42 days, with Sun + LEDs into 17.8 g L⁻¹ during 24 days when the both units reached the stationary phase of the growth curve. Biomass production was 3.3 in the Sun and 8.54 g m⁻² d⁻¹ in the Sun + LED, i.e. 0.27 and 0.68 g L⁻¹ d⁻¹. In total, the mean of 37.5 and 58.2 kWh per night were consumed, so the total electricity consumptions for biomass production was 0.20 and 0.40 kWh g⁻¹ DW during LED + Sun cycles 1 and 2, respectively. The production of the extracellular polysaccharides was practically the same for both platforms, and constant during time. A more substantial double increase was only after 30 days of cultivation in both platforms and reached 4 g L⁻¹. The fluorescence measurements proved good physiological state of the cultures. The PAR was found as a main driver of the photosynthetic activity. The correlation of the growth and fluorescence parameters to the environmental conditions was much more profound in the Sun pilot plant, therefore the reliable set of monitored parameters should be defined according to the cultivation type, for both of them we propose OD₆₈₀/OD₇₂₀ ratio as a proxy of nutrient deficiency.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"84 ","pages":"Article 103759"},"PeriodicalIF":4.6,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532511","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":"Magnetically separable sorbent based on activated carbon derived from a new precursor Rhizoclonium hookeri for facile oil spill clean-up","authors":"Saima Sohni ,&nbsp;Owais Rashid ,&nbsp;Sayyed Hamid Ali ,&nbsp;Sher Bahadar Khan ,&nbsp;Kalsoom Akhtar ,&nbsp;Faryal Mazhar ,&nbsp;Md. Sohrab Hossain ,&nbsp;Murtaza Sayed ,&nbsp;Najeeb Ullah","doi":"10.1016/j.algal.2024.103762","DOIUrl":"10.1016/j.algal.2024.103762","url":null,"abstract":"<div><div>A huge quantity of synthetic toxic materials ends-up in water bodies causing long-lasting environmental and economic impacts due to catastrophic oil spill. Exploring marine algae as sorbent materials for oil spill remediation is a relatively new area and holds great potential. Herein, macroalgae <em>Rhizoclonium hookeri</em> (RH) derived magnetically recoverable activated carbon (RHAC@Fe₃O₄) composite has been proposed as an innovative and robust strategy for oil spill clean-up. The oil uptake efficiency of RHAC@Fe₃O₄ was probed using unused and used motor oil in synthetic seawater matrices by conducting batch wise experiments. Optimal conditions for the designed sorption system were met by varying time (10–60 min), dosage (0.2–1 g) and temperature (20, 30, 40 °C). Characterization studies showed that KOH-based activation played a vital role in developing pore structure and surface functionalities in the algal biochar. Batch experiments demonstrated over 90 % oil removal efficiency of RHAC@Fe₃O₄ from simulated oil spill after 30 min using 0.8 g of composite. Moreover, Fe₃O₄ loading onto carbon material allowed magnetic separation as a convenient alternative to filtration for the recovery of oil laden composite. Apart from superior oil removal ability, synthesized composite demonstrated robust performance up to five cycles in synthetic sea water matrices. Additionally, comparative study revealed better oil sequestration efficiency of the fabricated RHAC@Fe₃O₄ composite (93 %) as compared to its precursors, i.e. algal biochar (71 %) and AC (88 %). Based on these findings, it is advocated that designed RHAC@Fe₃O₄ composite being eco-friendly, economical and readily recoverable with enhanced oil uptake ability could potentially be an innovative platform for oil spill clean-up applications.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"84 ","pages":"Article 103762"},"PeriodicalIF":4.6,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532324","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":"Quality and safety of fresh Spirulina (Arthrospira platensis) maintained by bubbling plasma-activated air","authors":"Odgerel Bumandalai ,&nbsp;Kirsty L. Bayliss ,&nbsp;Navid R. Moheimani","doi":"10.1016/j.algal.2024.103754","DOIUrl":"10.1016/j.algal.2024.103754","url":null,"abstract":"<div><div>Spirulina (<em>Arthrospira platensis</em>) is a blue-green alga valued for its protein, phycocyanin, and other bioactive compounds. However, its commercial outdoor cultivation makes it susceptible to microbial contamination, affecting both biomass productivity and quality. Additionally, most commercial Spirulina is sold in dried forms such as powder, flakes, and tablets, which can degrade these bioactive components. To address these issues, non-thermal techniques, such as cold plasma, offer a promising solution by effectively reducing microbial contamination while preserving product quality without the need for drying. This study investigated the potential of bubbling cold plasma-activated (BCPA) air through freshly grown Spirulina to reduce microbial contamination and maintain quality during storage. Spirulina grown in an outdoor paddle-wheel driven pond was harvested in paste form, resuspended in deionized water, treated with plasma-activated air and stored at 4 °C for 28 days. The treatment significantly reduced microbial contamination and maintained Spirulina biomass and pigment contents compared to untreated control. The cellular structure remained intact, and colour changes were minimal in the treated samples when compared to the controls. Moreover, the Spirulina suspension pH became acidic (pH = 4), and oxidation-reduction potential was significantly higher (&gt;150 mV) in treated samples compared to controls throughout the storage period. The results demonstrate the potential for BCPA air to maintain the quality of fresh Spirulina. This finding may have significant applications in the Spirulina industry for offering customers fresh products rather than dried Spirulina.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"84 ","pages":"Article 103754"},"PeriodicalIF":4.6,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The response mechanism of alkalophilic Nitzschia sp. NW129 to low alkalinity-A study combining physiological and transcriptional analysis","authors":"Zihao Cao ,&nbsp;Ruihao Zhang ,&nbsp;Xiaotong Shen ,&nbsp;Guanpin Yang ,&nbsp;Baohua Zhu ,&nbsp;Kehou Pan ,&nbsp;Tengfei Xiao ,&nbsp;Yun Li","doi":"10.1016/j.algal.2024.103748","DOIUrl":"10.1016/j.algal.2024.103748","url":null,"abstract":"<div><div>Global aquatic acidification significantly threatens alkaline lake ecosystems. The mechanisms by which alkaliphilic microalgae, the key producers in these ecosystems, respond to reduced environmental alkalinity remain poorly understood. Here, we investigated the responses of alkalophilic <em>Nitzschia</em> sp. NW129 to low alkalinity (pH 9.2) through integrated physiological-biochemical and transcriptomic analyses. Relative to the control (pH 11.5), we observed a 60.1 % decrease in polysaccharide content, while total lipids and proteins increased by 1.74-fold and 2-fold, respectively. Transcriptome analysis revealed up-regulation of genes encoding carbonic anhydrase (CA) and malic enzyme (ME), along with those involved in glycolysis and fatty acid (FA) synthesis, compensating for carbon supply and shifting carbon flux from carbohydrate synthesis to lipid accumulation. Enhanced expression of TCA cycle genes and those encoding F-ATP synthase and inorganic pyrophosphatase (PPase) provided sufficient energy for cellular homeostasis, further facilitated by the up-regulated expression of ATP-dependent V-ATPase and ABC transporter genes. Temporal analysis revealed that the expression of genes involved in protein synthesis pathways was up-regulated on days 1 and 4 but notably down-regulated on day 2, suggesting protein degradation at this time to balance energy supply for adaptation. Despite these coping shifts, impairments in photosynthetic energy dissipation and electron transport, along with transcriptional changes including down-regulating cell cycle and inducing apoptotic pathways, ultimately caused a substantial reduction in biomass. These findings provide a basic understanding of the response mechanisms of alkalophilic microalgae to low alkalinity stress, which should aid to develop strategies to improve microalgal tolerance against acidification.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"84 ","pages":"Article 103748"},"PeriodicalIF":4.6,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532327","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":"A reduced-order hybrid model for photobioreactor performance and biomass prediction","authors":"Shabnam Shahhoseyni,&nbsp;Lara Greco,&nbsp;Abhishek Sivaram,&nbsp;Seyed Soheil Mansouri","doi":"10.1016/j.algal.2024.103750","DOIUrl":"10.1016/j.algal.2024.103750","url":null,"abstract":"<div><div>This paper introduces a hybrid approach for photobioreactor modeling tailored to microalgae cultivation, combining data-driven and mechanistic concepts to improve modeling efficiency and practicality for industrial scale-up applications. Most growth models for microalgae are nonlinear and require experimental measurement of several parameters. The aim of this work is to develop linear practical models for monitoring purposes. A model based on linear coefficients and polynomial features is proposed, balancing interpretability with non-linear representation focusing on model transparency. To simplify the growth model, Taylor series expansion is applied to the Monod and logistic population models. Two scale-specific models are developed and evaluated, offering practical solutions for monitoring microalgae growth in photobioreactors. Therefore, this reduced order representation allows the biomass growth rate to be dependent directly on the biomass concentration. These models do not require exhaustive data collection of substrate concentration over time, making them cost-effective and efficient for industrial applications. This work provides a step forward in photobioreactor modeling, contributing to the sustainable production of microalgae.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"84 ","pages":"Article 103750"},"PeriodicalIF":4.6,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic behavior and transfer characteristics of CO2-enriched bubbles within Spirulina sp. suspension under various aeration conditions using the high-speed imaging technique","authors":"Hongyan Ren ,&nbsp;Mingwei Shen ,&nbsp;Duan Zhou ,&nbsp;Wei Wu ,&nbsp;Yahui Sun ,&nbsp;Kuan Shiong Khoo ,&nbsp;Pau Loke Show","doi":"10.1016/j.algal.2024.103758","DOIUrl":"10.1016/j.algal.2024.103758","url":null,"abstract":"<div><div>The biological CO₂ fixation method through microalgae photosynthesis has received considerable attention to alleviate the trend of global warming. CO₂-enriched gas is generally aerated into the microalgae suspension in the form of bubbles through the gas distributors. Dynamic behavior and transfer characteristics of CO₂-enriched bubbles are crucial to microalgae cells growth and CO₂ bio-fixation. A visual experimental system based on the high-speed camera was constructed in this work to obtain the dynamic behavior and transfer characteristics of CO₂-enriched bubbles within <em>Spirulina</em> sp. suspension. CO₂-enriched bubbles movement and dissolution characteristics were comprehensively investigated under various CO₂ concentrations, gas distributor aperture size, aeration rates, and <em>Spirulina</em> sp. biomass densities. Experimental results indicate that the optimal CO₂ dissolution mass transfer and absorption rate were attained under the CO₂ concentration of 5 %, gas distributor aperture diameter of 10 μm, and aeration rate of 0.1–0.3 vvm. Moreover, as <em>Spirulina</em> sp. biomass density increased, the bubble average diameter decreased, and rising velocity slowed while the volumetric mass transfer coefficient and CO₂ absorption rate elevated. To summarize, this work may guide future efforts to enhance the photobioreactors (PBRs) performance from the perspective of aeration conditions optimization.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"84 ","pages":"Article 103758"},"PeriodicalIF":4.6,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532512","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}