Algal Research-Biomass Biofuels and Bioproducts最新文献

{"title":"UV-B light (radiation) affects the metabolism of pigments and fatty acids in green algae Edaphochlorella mirabilis and Klebsormidium flaccidum in vitro","authors":"Giulia Santunione ,&nbsp;Francesca Masino ,&nbsp;Giuseppe Montevecchi ,&nbsp;Elisabetta Sgarbi","doi":"10.1016/j.algal.2024.103736","DOIUrl":"10.1016/j.algal.2024.103736","url":null,"abstract":"<div><div>Algae offer a rich source of bioactive compounds suitable for food products and bioenergy. Environmental challenges such as nutrient scarcity, extreme pH and temperature, high light intensity, and UV radiation usually trigger algae to produce excess of lipids, antioxidants, and other bioprotective molecules as part of their adaptations for survival. Algal cultivation provides proteins, lipids, carbohydrates, vitamins, antioxidants, and trace elements. This study focused on understanding how UV-B irradiance, as an abiotic stressor, can influence the growth and metabolite production of two green algal species, <em>Edaphochlorella mirabilis</em> (Chlorophyta) and <em>Klebsormidium flaccidum</em> (Charophyta). Using a temporary immersion system bioreactor for <em>in-vitro</em> algal growth, the results showed no significant difference in biomass for both algal species after the exposure to UV-B rays. However, the assessment of malondialdehyde levels revealed a significantly higher tendency towards lipid peroxidation in treated <em>E. mirabilis</em> (+ 90 %) compared to control. Conversely, <em>K. flaccidum</em> did not display significant differences, thereby highlighting a more advanced adaptive capacity against UV-B radiation<em>.</em> Overall, both algal species treated with UV-B showed increased pigment accumulation. <em>K. flaccidum</em> exhibited an average pigment increase of over 53 %, while <em>E. mirabilis</em> showed a lower increase, over 30 % on average. The notable rise in antioxidant compounds (lutein, β-carotene, and chlorophyll <em>a</em>) in UV-B exposed <em>K. flaccidum</em> samples also suggested a more suitable adaptive strategy to mitigate oxidative stress in Charophyta. In <em>K. flaccidum</em>, the increase in polyunsaturated fatty acids can be associated with increased production of antioxidant compounds. Conversely, <em>E. mirabilis</em> appeared to protect itself by decreasing polyunsaturated fatty acids in favor of saturated ones. In both algal species, the increase in secondary metabolites under UV stress highlighted potential as a novel food source for human consumption, deserving further investigation.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"83 ","pages":"Article 103736"},"PeriodicalIF":4.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418519","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":"Evaluation of the proximate composition and antioxidant capacity of some seaweeds from the Konkan coast of India","authors":"T.E.M.J.E.N.S.A.N.G.B.A. IMCHEN ,&nbsp;K.O.N.A.R.K. TRIPATHI ,&nbsp;R.E.S.H.M.I.T.H.A. RAMAKRISHNAN ,&nbsp;K.R.I.S.H.N.A. P. AKSHAY","doi":"10.1016/j.algal.2024.103730","DOIUrl":"10.1016/j.algal.2024.103730","url":null,"abstract":"<div><div>Minerals, antioxidants, and other nutrients that promote health can be found in abundance in seaweeds. In this study, we evaluated the proximate composition and antioxidant capacity of some seaweeds from Konkan coast of India. There were notable differences in the proximate compositions between the species. The highest protein content was found in <em>Pyropia vietnamensis</em> (~49 mg. g⁻¹ dw), whereas the highest carbohydrate (~83 mg. g⁻¹ dw), lipids (56 mg. g⁻¹ dw) and vitamins were found in <em>Stoechospermum marginatum</em>. Total phenolic content (TPC) and antioxidant activity were estimated from a Methanolic extracts. The antioxidant capacity of the seaweeds was evaluated using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, ABTS (2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid), ferric reducing antioxidant power (FRAP) assay and hydrogen peroxide free radical scavenging activity assay. Folin-Ciocalteu method was used to quantify total phenolic content (TPC), and <em>Ulva fasciata</em> had the highest TPC (24.30 ± 3 mg GAE. g⁻¹ dry weight). In <em>U. fasciata,</em> the antioxidant activity was ~62 %, with an IC₅₀ value of 0.057 ± 0.01 mM. <em>Acanthophora spicifera</em> was found to have a strong reducing power, with an IC₅₀ value 0.012 ± 0.002 mM. H₂O₂ scavenging activity (~79 %) with an IC₅₀ value of 0.006 ± 0.001 mM and 67 % ABTS radical scavenging activity (IC₅₀ = 0.005) was highest in <em>S. marginatum</em>. Analysis showed that TPC exhibited strong positive correlation with both the ferric reducing antioxidant potential and DPPH antioxidant activity. These results showed that these seaweeds have significant antioxidant capacity and rich nutritional properties, which suggest they could be useful sources of functional ingredients for dietary supplements and other food products.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"83 ","pages":"Article 103730"},"PeriodicalIF":4.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418518","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":"Improved hydrogen production in immobilized Chlamydomonas reinhardtii cells with inhibited inter-photosystem electron transfer","authors":"Fatemeh Khosravitabar ,&nbsp;Fikret Mamedov","doi":"10.1016/j.algal.2024.103732","DOIUrl":"10.1016/j.algal.2024.103732","url":null,"abstract":"<div><div>The production of molecular hydrogen (H₂) by microalgae holds great promise, and immobilization techniques offer potential for further advancement in this field. The current study focuses on investigating the positive impact of immobilization on maintaining the stability and activity of photosystem II (PSII) over incubation time, with the aim of enhancing H₂ production potential in green microalgae <em>Chlamydomonas reinhardtii</em>. For this purpose, immobilized cells within alginate beads were treated with small concentrations of 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB) inhibitor to induce the partial inhibition of inter-photosystem electron transport, recently reported as a novel approach for sustaining microalgal H₂ production. A comparative analysis of fluorescence decay kinetic changes and EPR spectroscopy of the cell beads revealed the superior capacity of immobilization for sustaining PSII stability and activity in batch culture over time. Treatment of the cell beads with 3.5 μM DBMIB led to sustained H₂ production yielding over 200 μmol H₂/mg Chl within 3 weeks, with an average H₂ production rate of approximately 10 μmol/mg Chl per day, both of which were roughly twice as high as those observed in free cells treated with DBMIB. Our findings underscore the significance of integrating immobilization with a proven and effective method for H₂ production, thereby enhancing its sustainability and productivity.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"83 ","pages":"Article 103732"},"PeriodicalIF":4.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418560","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":"Carotenoids from cyanobacteria modulate iNOS and inhibit the production of inflammatory mediators: Promising agents for the treatment of inflammatory conditions","authors":"Janaína Morone ,&nbsp;Guilherme Hentschke ,&nbsp;Eugénia Pinto ,&nbsp;João Morais ,&nbsp;Pedro Cruz ,&nbsp;Vitor Vasconcelos ,&nbsp;Rosário Martins ,&nbsp;Graciliana Lopes","doi":"10.1016/j.algal.2024.103729","DOIUrl":"10.1016/j.algal.2024.103729","url":null,"abstract":"<div><div>Cyanobacteria are green multiproduct refineries of increasing interest for different industrial prospects. In this work, eleven cyanobacteria strains isolated from the Cape Verde archipelago were explored for their biotechnological applications in the field of inflammation. A biorefinery approach was employed to produce carotenoid-targeted extracts, further profiled by HPLC-PDA and explored for their ability to <em>i</em>) scavenge important physiological free radicals of oxygen (superoxide anion radical, O₂^•-) and nitrogen (nitric oxide, ^•NO) involved in the inflammatory process <em>ii</em>) slow-down post-inflammatory hyperpigmentation and <em>iii</em>) modulate the activity of inflammatory cytokine-producing enzymes, in enzymatic and cell systems comprising RAW 264.7 cells. The studied strains turned out to be important carotenoid producers (70.47–186.71 μg mg⁻¹dry extract), mainly represented by β-carotene and zeaxanthin. The targeted-extracts stood-out for their potential to slow-down the inflammatory process through a multitarget approach: scavenging ^•NO and O₂^•-, reducing inflammatory cytokines production through lipoxygenase inhibition, and modulating the inducible nitric oxide synthase in LPS-stimulated RAW 264.7 cells, with strains of the order Nodosilineales revealing to be worth of further biotechnological exploitation.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"83 ","pages":"Article 103729"},"PeriodicalIF":4.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418598","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":"Microencapsulation of a green microalga (Chlorella vulgaris) by complex coacervation for its valuation as a feasible ingredient in pear snacks","authors":"Nadjet Djihad ,&nbsp;Naima Fadloun Oukil ,&nbsp;Sarah Hamid ,&nbsp;Amel Attia ,&nbsp;Sílvia Petronilho","doi":"10.1016/j.algal.2024.103727","DOIUrl":"10.1016/j.algal.2024.103727","url":null,"abstract":"<div><div>The nutritional and bioactivity values of <em>Chlorella vulgaris</em> make this green microalga a potential functional food ingredient. However, its unpleasant taste and smell, as well as dark green color, have been considered restrictive for its consumers' acceptability. Here, it was hypothesized that complex coacervation can be used to produce microcapsules able to mitigate the sensory weaknesses of <em>C. vulgaris</em> in think pear snacks, while ensuring their acceptance and intention to buy. For this, two proteins with similar isoelectric points were used, the pea protein isolate (PPI) and the bovine serum albumin (BSA), while the partially-sulfated carrageenan (C) was the selected polysaccharide to encapsulate <em>C. vulgaris</em> (6 % <em>w</em>/w), at pH 3. Higher encapsulation yield (79 %) and efficiency (75 %) were obtained for PPI/C coacervates due to these polymers' higher electrostatic interaction at pH 3, contrasting with the higher repulsion promoted by some negatively charged BSA amino acids. Despite this, both microcapsules exhibited an amorphous structure and low water activity (a_w around 0.3). However, PPI/C microcapsules had significantly lower moisture and water solubility (11 % and 57 %, respectively), as well as continuous shells. Moreover, PPI/C avoided the early release of <em>C. vulgaris</em> compounds at gastric conditions ensuring its later release in the intestinal tract. When incorporated into think pear snacks, the higher sensory scores and buying intention were obtained for snacks with PPI/C microcapsules containing <em>C. vulgaris</em>. Therefore, complex coacervation, particularly of PPI/C, allowed to mitigate non-valued microalga sensory attributes contributing for the future acceptance and consumption of algae-based food products.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"83 ","pages":"Article 103727"},"PeriodicalIF":4.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358926","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":"Substrate functionalization by cold plasma treatments as an alternative process to the cultivation of microalgae in biofilm: Application to Botryococcus","authors":"Gabriel Giannini Beillon ,&nbsp;Brigitte Veidl ,&nbsp;Justine Marchand ,&nbsp;Fabienne Poncin-Epaillard ,&nbsp;Benoît Schoefs","doi":"10.1016/j.algal.2024.103728","DOIUrl":"10.1016/j.algal.2024.103728","url":null,"abstract":"<div><div>Microalgae are renowned for their diverse production of molecules, including biofuels. However, biotechnological processes aiming at producing these biomolecules have yet to achieve economic sustainability due to the high costs associated with downstream processing, which can make up to 80 % of the total production costs. Since microalgae immobilized on a flat surface are characterized by a higher productivity and an easier harvesting than bulk culture systems, flat cultures may present better economic viability. Nevertheless, immobilizing filamentous or colonial microalgae on a flat surface is challenging due to their inherent 3D development. In this study, we explored the effectiveness of a plasma-modified polyethylene terephthalate flat surface for improving the immobilization of the green freshwater colonial microalga <em>Botryococcus protuberans</em>, a promising taxon for biofuel production. Plasma treatments were found to alter the wettability and surface energy of polyethylene terephthalate substrates. <em>Botryococcus</em> adhesion was enhanced significantly on O₂ plasma-modified substrates compared to untreated substrates. The adhesion was strong enough to prevent colony development in the water column while allowing the development of a biofilm over one month, with minimal impact on their physiology.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"83 ","pages":"Article 103728"},"PeriodicalIF":4.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418445","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":"Microalgae as feed additives in poultry: A review on the health-promoting effects","authors":"Sofie Van Nerom ,&nbsp;Bert Coleman ,&nbsp;Renée De Baets ,&nbsp;Filip Van Immerseel ,&nbsp;Johan Robbens ,&nbsp;Evelyne Delezie","doi":"10.1016/j.algal.2024.103733","DOIUrl":"10.1016/j.algal.2024.103733","url":null,"abstract":"<div><div>This review explores the effects of the inclusion of microalgal biomass in feed on the health of poultry (broilers and laying hens). Microalgae have emerged as a promising feed additive, valued not only for their rich nutritional profile, but also for their bioactive substances. Bioactive compounds, such as phenolics, polyunsaturated fatty acids, oligosaccharides and carotenoids, exhibit antioxidant, anti-inflammatory, antibacterial, and antiviral functions, which hold promise for promoting poultry health. With the ban on prophylactic antibiotic use in feed, microalgal biomass emerges as an innovative feed additive to enhance growth performance and prevent health issues in poultry. This review extensively explains the critical health parameters of poultry, including histology of the intestinal tract, intestinal permeability, immunity, antioxidant status and prebiotic effects on the intestinal microbiome. Furthermore, it offers valuable insights into the inclusion of microalgae in poultry feed, promoting these health parameters. It concludes with suggestions for further research and practical recommendations on how to improve poultry health using microalgal biomass.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"83 ","pages":"Article 103733"},"PeriodicalIF":4.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418446","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":"Ambivalent effects of mass cultivation of biodiesel producible green alga Tetraselmis striata on a microbial ecosystem: Evidence from mesocosm experiments","authors":"Sae-Hee Kim ,&nbsp;Jin Ho Kim ,&nbsp;Joo-Hwan Kim ,&nbsp;Pengbin Wang ,&nbsp;Tae Gyu Park ,&nbsp;Sangsuk Park ,&nbsp;Yoon-Ho Kang ,&nbsp;Myung-Soo Han ,&nbsp;Bum Soo Park","doi":"10.1016/j.algal.2024.103735","DOIUrl":"10.1016/j.algal.2024.103735","url":null,"abstract":"<div><div>A 280-ton plant for the mass cultivation of <em>Tetraselmis striata</em> was operated from 2012 to 2019 to produce biodiesel fuel in western Korean coastal waters (Incheon) as a pilot project. This was the first instance globally where a microalgal mass cultivation plant for biodiesel production was implemented in coastal waters, and no prior studies had investigated the impact of microalgal mass cultivation plant on surrounding microecosystems. In this study, bioreactors (1× and 10×) mimicking a large-scale <em>T. striata</em> cultivation plant were installed in semi-permeable a mesocosms (5 tons) to assess their impact on the microbial ecosystem. The results showed that the release of large amounts of dissolve organic carbon (DOC) from the <em>T. striata</em> bioreactors. The 10× pond had a DOC concentration of 21.3 mg/L compared to the control pond of 2.1 mg/L. For the Water Quality Index (WQI), the 1× and 10× bioreactor installed mesocosms improved from Class II (Good) at the beginning of the experiment to Class I (Excellent) via decreasing nutrient levels and increasing of DO levels. However, from a biodiversity perspective, the microbial ecosystem deteriorated, with reductions in the diversity of zooplankton, ciliates, and phytoplankton. The correlation analysis and random forest variable importance measures indicated that the primary factor driving these changes was the alteration of the bacterial community due to elevated DOC levels. These findings indicate that while the mass cultivation of <em>T. striata</em> may improve physicochemical water quality, it has adverse effects on biological environments. Therefore, it is crucial to monitor physical, chemical, and biological factors comprehensively when cultivating microalgae on a large scale in marine environments.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"83 ","pages":"Article 103735"},"PeriodicalIF":4.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418520","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":"Enhancing nutrient bioavailability in distillery wastewater through electrochemical oxidation for microalgal growth: Insights on biomass yield, nutrient utilisation, and VFA-assisted carbon capture","authors":"Inigo Johnson ,&nbsp;Chandraraj Krishnan ,&nbsp;Mathava Kumar","doi":"10.1016/j.algal.2024.103734","DOIUrl":"10.1016/j.algal.2024.103734","url":null,"abstract":"<div><div>Two-stage treatment of distillery wastewater (DWW) via electrochemical oxidation (EO) using Ti-RuO₂ anodes (35 cm² area) followed by mixotrophic microalgal treatment was investigated. In the first-stage, EO of DWW has improved the bioavailability of nitrogen and phosphorus at 3.95–5.14 mg/Ah and 0.43–1.02 mg/Ah, respectively, which had strong correlation with current density. EO also reduced ∼30 % TOC, 53 % COD and ∼44 % TN. In the second-stage, the ability of a novel microalgae, <em>Asterarsys quadricellulare</em> to mitigate the toxicity of electrochemically oxidised DWW (EO-DWW) while utilising the nutrients effectively was investigated. The mixotrophic algal growth effectively utilised 85 % phosphate and 91 % nitrate present in EO-DWW at a corresponding growth rate of 0.73 d⁻¹. The algal biomass was found to have ∼15 % carbohydrates, ∼12 % lipids and ∼33 % proteins. Subsequently, a bench-scale bubble column photobioreactor investigation was carried out to understand the carbon dynamics during the growth of <em>Asterarsys quadricellulare</em>. The metabolic uptake of monocarboxylic volatile fatty acids (VFA) and nitrate were found to release OH⁻ ions, which eventually helped in dissolving CO₂ in the reactor through a diffusion-limited process. The total energy spent in bench-scale EO system was 840 kWh (3024 kJ) per L of DWW, and the energy recovery potential of second-stage algal reactor was ∼8.7 %. The microtoxicity experiments with <em>Alivibrio fischeri</em> revealed that two-stage treated DWW was found to be safe for reuse as the microalgal growth has abated the toxicity of EO-DWW.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"83 ","pages":"Article 103734"},"PeriodicalIF":4.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418559","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 cellulose nanocrystals on the emulsion stability and rheological properties of microalgal Pickering emulsions","authors":"Wonsik Shin ,&nbsp;Joung Sook Hong ,&nbsp;Dae Yeon Kim ,&nbsp;Si Yoon Kim ,&nbsp;Kyu Hyun ,&nbsp;Jun Dong Park ,&nbsp;Kyung Hyun Ahn","doi":"10.1016/j.algal.2024.103731","DOIUrl":"10.1016/j.algal.2024.103731","url":null,"abstract":"<div><div>This study investigates the effect of cellulose nanocrystals (CNCs) to Pickering emulsions prepared with microalgal particles (<em>Spirulina</em> sp. (SPI), <em>Chlorella</em> sp. HS2 (CLO)). The microalgae particles show a weak interfacial localization and Pickering behavior on the O/W emulsion depending on the size (avg. drop size ∼5.39 μm with SPI and 22.15 μm with CLO), resulting in a different stabilization effect. When CNC is additionally mixed with the Pickering emulsions including large microalgae particles (CLO), CNC replaces microalgae particles and localizes at the interface, enhancing strong emulsion stabilization. For the Pickering emulsions including small microalgae (SPI), CNC localizes at the continuous phase, forming a network structure regardless of the concentration. This interfacial localization behavior of CNC against microalgae particles is reflected in the rheological behavior of the Pickering emulsion. Depending on the location of CNC, the emulsions exhibit the two-step yielding behavior, mainly attributed to the CNC network in the continuous phase. The complex role of particles in the emulsion system is more sensitively reflected in the large amplitude oscillatory shear (LAOS) region, characterized using the sequence of physical process (SPP) rheological analysis. The maximum elasticity (E_max) in SPP analysis, which indicates the recovery of the deformed structure, exhibits a significant difference, discriminating structural characteristics of CNC dispersion incorporated with microalgae particles. Emulsion with CLO-CNC has lower E_max than the SPI-CNC case because CNC particles disperse at the interface and the continuous phase. Then the distance between CNC particles is longer, resulting in a weak network structure throughout the emulsion. Due to a weak network of CNC, the emulsion is more vulnerable to coalescence compared to the SPI-CNC system. Therefore, this study suggests that CNC particles added to the Pickering emulsion with microalgae compete to localize at the interface and give coalescence suppression effects to the emulsion. Also, for the Pickering emulsion system composed of multi-particles, rheological analysis including SPP analysis successfully indicates structural characteristics and flow-induced stabilization of Pickering emulsions with multi-particles that microscopic characterization could not detect.</div></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":"83 ","pages":"Article 103731"},"PeriodicalIF":4.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418561","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}