{"title":"小球藻对光线骤变的适应动态","authors":"","doi":"10.1016/j.algal.2024.103661","DOIUrl":null,"url":null,"abstract":"<div><p><em>Chlorella vulgaris</em> photoacclimation was monitored over eight instantaneous light intensity changes. The intensities ranged between <span><math><mn>35</mn><mspace></mspace><mi>μmol Photo</mi><msub><mi>n</mi><mi>PAR</mi></msub><mo>.</mo><msup><mi>m</mi><mrow><mo>−</mo><mn>2</mn></mrow></msup><mo>.</mo><msup><mi>s</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span> and <span><math><mn>600</mn><mi>μmolPhoto</mi><msub><mi>n</mi><mi>PAR</mi></msub><mo>.</mo><msup><mi>m</mi><mrow><mo>−</mo><mn>2</mn></mrow></msup><mo>.</mo><msup><mi>s</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span>. Cultures were grown in ultra-thin flat panel photobioreactors under continuous light and maintained in low cell density to ensure homogeneous light availability. Photoacclimation was evaluated through spectral quantification of pigments and fluorometric assays. The former gave access to a proxy of chlorophyll and carotenoid content, the latter to the Photosystem-II cross-section (<span><math><msub><mi>σ</mi><mi>PSII</mi></msub></math></span>) and qualification of the photosynthetic machinery (<em>via</em> <span><math><mi>OJIP</mi></math></span> assays). Both the acclimated steady-state values of pigment content and the dynamic of their evolutions after sudden light intensity change were monitored. The characteristic times of the transitions were estimated based on a first-order assumption. Results consistently showed that antenna size adjustment of <em>Chlorella vulgaris</em> was primarily dictated by the light availability, both regarding the acclimated steady-state values and the acclimation dynamics. An energetic limitation was highlighted by the acclimation dynamics at low light. The characteristic time of transition was estimated to be <span><math><mn>16.6</mn><mo>±</mo><mn>2.17</mn><mi>h</mi></math></span> for the transition to the lowest light intensity (<span><math><mn>35</mn><mspace></mspace><mi>μmol Photo</mi><msub><mi>n</mi><mi>PAR</mi></msub><mo>.</mo><msup><mi>m</mi><mrow><mo>−</mo><mn>2</mn></mrow></msup><mo>.</mo><msup><mi>s</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span>) and <span><math><mn>3.55</mn><mo>±</mo><mn>1.01</mn><mi>h</mi></math></span> for intensities higher than the maximal intensity of photolimitation (<span><math><mn>120</mn><mspace></mspace><mi>μmol Photo</mi><msub><mi>n</mi><mi>PAR</mi></msub><mo>.</mo><msup><mi>m</mi><mrow><mo>−</mo><mn>2</mn></mrow></msup><mo>.</mo><msup><mi>s</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span>). No hysteresis effect was observed as light intensities were shifted once and reverted to their original values. These results extend the literature regarding photoacclimation dynamics of antenna size and photosynthetic apparatus. They are well-suited to calibrate photoacclimation models and can provide valuable insight into the strategies to implement for culture scale-up, fed-batch, and semi-continuous processes.</p></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":null,"pages":null},"PeriodicalIF":4.6000,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S221192642400273X/pdfft?md5=4eb64ec491f54e4ee85fd53453c8565e&pid=1-s2.0-S221192642400273X-main.pdf","citationCount":"0","resultStr":"{\"title\":\"Acclimation dynamics of Chlorella vulgaris to sudden light change\",\"authors\":\"\",\"doi\":\"10.1016/j.algal.2024.103661\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p><em>Chlorella vulgaris</em> photoacclimation was monitored over eight instantaneous light intensity changes. The intensities ranged between <span><math><mn>35</mn><mspace></mspace><mi>μmol Photo</mi><msub><mi>n</mi><mi>PAR</mi></msub><mo>.</mo><msup><mi>m</mi><mrow><mo>−</mo><mn>2</mn></mrow></msup><mo>.</mo><msup><mi>s</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span> and <span><math><mn>600</mn><mi>μmolPhoto</mi><msub><mi>n</mi><mi>PAR</mi></msub><mo>.</mo><msup><mi>m</mi><mrow><mo>−</mo><mn>2</mn></mrow></msup><mo>.</mo><msup><mi>s</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span>. Cultures were grown in ultra-thin flat panel photobioreactors under continuous light and maintained in low cell density to ensure homogeneous light availability. Photoacclimation was evaluated through spectral quantification of pigments and fluorometric assays. The former gave access to a proxy of chlorophyll and carotenoid content, the latter to the Photosystem-II cross-section (<span><math><msub><mi>σ</mi><mi>PSII</mi></msub></math></span>) and qualification of the photosynthetic machinery (<em>via</em> <span><math><mi>OJIP</mi></math></span> assays). Both the acclimated steady-state values of pigment content and the dynamic of their evolutions after sudden light intensity change were monitored. The characteristic times of the transitions were estimated based on a first-order assumption. Results consistently showed that antenna size adjustment of <em>Chlorella vulgaris</em> was primarily dictated by the light availability, both regarding the acclimated steady-state values and the acclimation dynamics. An energetic limitation was highlighted by the acclimation dynamics at low light. The characteristic time of transition was estimated to be <span><math><mn>16.6</mn><mo>±</mo><mn>2.17</mn><mi>h</mi></math></span> for the transition to the lowest light intensity (<span><math><mn>35</mn><mspace></mspace><mi>μmol Photo</mi><msub><mi>n</mi><mi>PAR</mi></msub><mo>.</mo><msup><mi>m</mi><mrow><mo>−</mo><mn>2</mn></mrow></msup><mo>.</mo><msup><mi>s</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span>) and <span><math><mn>3.55</mn><mo>±</mo><mn>1.01</mn><mi>h</mi></math></span> for intensities higher than the maximal intensity of photolimitation (<span><math><mn>120</mn><mspace></mspace><mi>μmol Photo</mi><msub><mi>n</mi><mi>PAR</mi></msub><mo>.</mo><msup><mi>m</mi><mrow><mo>−</mo><mn>2</mn></mrow></msup><mo>.</mo><msup><mi>s</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span>). No hysteresis effect was observed as light intensities were shifted once and reverted to their original values. These results extend the literature regarding photoacclimation dynamics of antenna size and photosynthetic apparatus. They are well-suited to calibrate photoacclimation models and can provide valuable insight into the strategies to implement for culture scale-up, fed-batch, and semi-continuous processes.</p></div>\",\"PeriodicalId\":7855,\"journal\":{\"name\":\"Algal Research-Biomass Biofuels and Bioproducts\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":4.6000,\"publicationDate\":\"2024-08-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S221192642400273X/pdfft?md5=4eb64ec491f54e4ee85fd53453c8565e&pid=1-s2.0-S221192642400273X-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Algal Research-Biomass Biofuels and Bioproducts\",\"FirstCategoryId\":\"99\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S221192642400273X\",\"RegionNum\":2,\"RegionCategory\":\"生物学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"BIOTECHNOLOGY & APPLIED MICROBIOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Algal Research-Biomass Biofuels and Bioproducts","FirstCategoryId":"99","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S221192642400273X","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"BIOTECHNOLOGY & APPLIED MICROBIOLOGY","Score":null,"Total":0}
Acclimation dynamics of Chlorella vulgaris to sudden light change
Chlorella vulgaris photoacclimation was monitored over eight instantaneous light intensity changes. The intensities ranged between and . Cultures were grown in ultra-thin flat panel photobioreactors under continuous light and maintained in low cell density to ensure homogeneous light availability. Photoacclimation was evaluated through spectral quantification of pigments and fluorometric assays. The former gave access to a proxy of chlorophyll and carotenoid content, the latter to the Photosystem-II cross-section () and qualification of the photosynthetic machinery (via assays). Both the acclimated steady-state values of pigment content and the dynamic of their evolutions after sudden light intensity change were monitored. The characteristic times of the transitions were estimated based on a first-order assumption. Results consistently showed that antenna size adjustment of Chlorella vulgaris was primarily dictated by the light availability, both regarding the acclimated steady-state values and the acclimation dynamics. An energetic limitation was highlighted by the acclimation dynamics at low light. The characteristic time of transition was estimated to be for the transition to the lowest light intensity () and for intensities higher than the maximal intensity of photolimitation (). No hysteresis effect was observed as light intensities were shifted once and reverted to their original values. These results extend the literature regarding photoacclimation dynamics of antenna size and photosynthetic apparatus. They are well-suited to calibrate photoacclimation models and can provide valuable insight into the strategies to implement for culture scale-up, fed-batch, and semi-continuous processes.
期刊介绍:
Algal Research is an international phycology journal covering all areas of emerging technologies in algae biology, biomass production, cultivation, harvesting, extraction, bioproducts, biorefinery, engineering, and econometrics. Algae is defined to include cyanobacteria, microalgae, and protists and symbionts of interest in biotechnology. The journal publishes original research and reviews for the following scope: algal biology, including but not exclusive to: phylogeny, biodiversity, molecular traits, metabolic regulation, and genetic engineering, algal cultivation, e.g. phototrophic systems, heterotrophic systems, and mixotrophic systems, algal harvesting and extraction systems, biotechnology to convert algal biomass and components into biofuels and bioproducts, e.g., nutraceuticals, pharmaceuticals, animal feed, plastics, etc. algal products and their economic assessment