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Xu Z, Yang S, Li M, Bao M, Wu H. Warming modulates the photosynthetic performance of Thalassiosira pseudonana in response to UV radiation. Front Microbiol 2023; 14:1284792. [PMID: 38029218 PMCID: PMC10644151 DOI: 10.3389/fmicb.2023.1284792] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 10/18/2023] [Indexed: 12/01/2023] Open
Abstract
Diatoms form a major component of phytoplankton. These eukaryotic organisms are responsible for approximately 40% of primary productivity in the oceans and contribute significantly to the food web. Here, the influences of ultraviolet radiation (UVR) and ocean warming on diatom photosynthesis were investigated in Thalassiosira pseudonana. The organism was grown at two temperatures, namely, 18°C, the present surface water temperature in summer, and 24°C, an estimate of surface temperature in the year 2,100, under conditions of high photosynthetically active radiation (P, 400-700 nm) alone or in combination with UVR (P + UVR, 295-700 nm). It was found that the maximum photochemical yield of PSII (Fv/Fm) in T. pseudonana was significantly decreased by the radiation exposure with UVR at low temperature, while the rise of temperature alleviated the inhibition induced by UVR. The analysis of PSII subunits turnover showed that high temperature alone or worked synergistically with UVR provoking fast removal of PsbA protein (KPsbA), and also could maintain high PsbD pool in T. pseudonana cells. With the facilitation of PSII repair process, less non-photochemical quenching (NPQ) occurred at high temperature when cells were exposed to P or P + UVR. In addition, irrespective of radiation treatments, high temperature stimulated the induction of SOD activity, which partly contributed to the higher PSII repair rate constant (Krec) as compared to KPsbA. Our findings suggest that the rise in temperature could benefit the photosynthetic performance of T. pseudonana via modulation of its PSII repair cycle and protective capacity, affecting its abundance in phytoplankton in the future warming ocean.
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Affiliation(s)
- Zhiguang Xu
- School of Life Science, Ludong University, Yantai, China
- Key Laboratory of Marine Biotechnology in Universities of Shandong, Ludong University, Yantai, China
| | - Shunda Yang
- School of Life Science, Ludong University, Yantai, China
- Key Laboratory of Marine Biotechnology in Universities of Shandong, Ludong University, Yantai, China
| | - Mingze Li
- School of Life Science, Ludong University, Yantai, China
- Key Laboratory of Marine Biotechnology in Universities of Shandong, Ludong University, Yantai, China
| | - Menglin Bao
- School of Life Science, Ludong University, Yantai, China
- Key Laboratory of Marine Biotechnology in Universities of Shandong, Ludong University, Yantai, China
| | - Hongyan Wu
- School of Life Science, Ludong University, Yantai, China
- Key Laboratory of Marine Biotechnology in Universities of Shandong, Ludong University, Yantai, China
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Comparison of Growth and Chemical Profile of Diatom Skeletonema grevillei in Bioreactor and Incubation-Shaking Cabinet in Two Growth Phases. Mar Drugs 2022; 20:md20110697. [PMID: 36355020 PMCID: PMC9695663 DOI: 10.3390/md20110697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/04/2022] [Accepted: 11/04/2022] [Indexed: 11/09/2022] Open
Abstract
Marine microalgae, diatoms, are considered a source of a wide range of high-value compounds, and numerous studies indicate their biotechnological potential in the food and feed industry, cosmetic industry, nanotechnology, pharmaceutical industry, biodiesel production, fertilizers, and wastewater treatment. The aim of this study was to compare the growth, chemical profiles, and antioxidant activity of the diatom Skeletonema grevillei cultivated in a bioreactor and an incubation-shaking cabinet at different growth phases (after 192 and 312 h). Growth was monitored by evaluating cell density with the Sedgewick Rafter chamber, and the collected biomass was extracted with 70% ethanol assisted by ultrasound. Extracts were evaporated to dryness and compounds were identified in derivatized form by gas chromatography and mass spectrometry (GC-MS) analysis, while antioxidant capacity was evaluated by DPPH and ORAC. Significantly faster growth was observed in the bioreactor than in the incubation-shaking cabinet. Oleamide, palmitelaidic acid, glycerol monostearate, myristic acid, cholesterol, eicosapentaenoic acid, 1-monopalmitin, and 24-methylene cholesterol were identified as the major compounds in both systems. Among them, oleamide was the dominant compound in both systems. It is also shown that prolonging the cultivation period had a direct effect on increasing the extract yield. The highest DPPH inhibition (11.4 ± 1%) and ORAC values (93.3 ± 8.4 mM TE) were obtained for the S. grevillei extract recovered from the bioreactor after 312 h. The obtained results contribute to the possibility of using S. grevillei for various biotechnological applications in the future.
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Xie L, Macken A, Johnsen B, Norli M, Segtnan Skogan OA, Tollefsen KE. The MicroClimate Screen - A microscale climate exposure system for assessing the effect of CO 2, temperature and UV on marine microalgae. MARINE ENVIRONMENTAL RESEARCH 2022; 179:105670. [PMID: 35728490 DOI: 10.1016/j.marenvres.2022.105670] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 05/16/2022] [Accepted: 05/29/2022] [Indexed: 06/15/2023]
Abstract
Global warming and anthropogenic activities are changing the ocean, inducing profound impacts on marine life and ecosystems from changing physical and chemical factors in and above the water column. Rising surface temperatures, ocean acidification, and seasonal variations in UV radiation (UVR), modulated by water clarity and sea-ice extent, affect life cycles of the marine food-web, and directly or indirectly also the global carbon fixation. Diatoms, pelagic microalgae that are responsible for 40% of the marine productivity, have limited capability to avoid exposure to changing ocean conditions, and hence, highly relevant for model studies of the influence of climate change on growth and productivity in the marine environment. A plate-based high-throughput exposure system was constructed to assess the biological effects from relevant climate change factors on the diatom Skeletonema pseudocostatum, conducted as a chronic toxicity tests over 72 h periods. The exposure system consisted of a micro-climate unit and a light-exposure unit, enabling accurate regulation of pCO2, temperature, UVR and photosynthetic active radiation (PAR). Changes in physical factors, including pH, dissolved inorganic carbon (DIC), total alkalinity (TA), temperature and salinity in the medium, as well as reduction in growth were characterised to demonstrate performance of the micro exposure system. The results demonstrate that the exposure system successfully simulated ocean acidification and could maintain stable temperature (CV < 3%), PAR and UVR irradiance (CV < 8%). Growth inhibition responses were typically dose-dependent and verified that the micro-exposure system could be used to assess effects and adaptions to climate-relevant stressors.
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Affiliation(s)
- Li Xie
- Norwegian Institute for Water Research (NIVA), Økernveien 94, N-0579, OSLO, Norway; Norwegian University of Life Sciences (NMBU), Centre for Environmental Radioactivity, Post box 5003, N-1432, Ås, Norway
| | - Ailbhe Macken
- Norwegian Institute for Water Research (NIVA), Økernveien 94, N-0579, OSLO, Norway
| | - Bjørn Johnsen
- Norwegian Radiation and Nuclear Safety Authority (DSA), Grini Næringspark 13, NO-1361, Østerås, Norway
| | - Marit Norli
- Norwegian Institute for Water Research (NIVA), Økernveien 94, N-0579, OSLO, Norway
| | | | - Knut Erik Tollefsen
- Norwegian Institute for Water Research (NIVA), Økernveien 94, N-0579, OSLO, Norway; Norwegian University of Life Sciences (NMBU), Centre for Environmental Radioactivity, Post box 5003, N-1432, Ås, Norway; Norwegian University of Life Sciences (NMBU), Faculty of Environmental Sciences and Natural Resource Management, Post box 5003, N-1432, Ås, Norway.
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Xie S, Lin F, Zhao X, Gao G. Enhanced lipid productivity coupled with carbon and nitrogen removal of the diatom Skeletonema costatum cultured in the high CO2 level. ALGAL RES 2022. [DOI: 10.1016/j.algal.2021.102589] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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Wen J, Zou D. Interactive effects of increasing atmospheric CO 2 and copper exposure on the growth and photosynthesis in the young sporophytes of Sargassum fusiforme (Phaeophyta). CHEMOSPHERE 2021; 269:129397. [PMID: 33383248 DOI: 10.1016/j.chemosphere.2020.129397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 12/13/2020] [Accepted: 12/18/2020] [Indexed: 06/12/2023]
Abstract
Little attention has been given to the combined effects of elevated atmospheric CO2-induced ocean acidification (OA) and heavy metal pollution on marine macroalgae at the young stage. This study investigated the mutual effects of copper (Cu) and elevated CO2 on the young sporophytes of brown macroalgae Sargassum fusiforme. A matrix of four copper concentrations, 0, 0.025, 0.075 and 0.15 mg‧L-1, and two levels of CO2 (ambient CO2: 400 μatm; elevated CO2: 1,000 μatm) were used. High concentration of copper exposure greatly depressed photosynthesis and growth of the young sporophytes of S. fusiforme by reducing the apparent photosynthetic efficiency (ɑ), maximum net photosynthetic oxygen evolution rate (Pmax), maximum photochemical quantum yield (Fv/Fm) and pigments content (Chl a and Car). While elevated CO2 alone had obscure impact on this alga. However, the inhibition of Cu stress on Fv/Fm was weakened by elevated CO2, which also decreased the light compensation point (Ic). Meanwhile, the Cu2+-induced ascent in the dark respiration rate (Rd) and superoxide dismutase (SOD) activity was mitigated under the growth with elevated CO2, suggesting an alleviated oxidative stress. Overall, we propose that, under CO2 enrichment condition, the young sporophytes of S. fusiforme may increase photosynthesis efficiency and synthesize less enzymatic antioxidants in face of increasing Cu stress.
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Affiliation(s)
- Jiayi Wen
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China
| | - Dinghui Zou
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; Key Laboratory of Atmospheric Environment and Pollution Control, South China University of Technology, Guangzhou, 510006, China.
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Qiao H, Zang S, Yan F, Xu Z, Wang L, Wu H. Physiological responses of the diatoms Thalassiosira weissflogii and Thalassiosira pseudonana to nitrogen starvation and high light. MARINE ENVIRONMENTAL RESEARCH 2021; 166:105276. [PMID: 33578138 DOI: 10.1016/j.marenvres.2021.105276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 01/24/2021] [Accepted: 01/30/2021] [Indexed: 06/12/2023]
Abstract
As oceans warm, the depth of the upper mixed layer is predicted to decrease, resulting in insufficient nutrient supply and higher solar radiation for phytoplankton. In order to understand the photophysiological responses of the key eukaryotic phytoplankton diatoms to high light and nutrient limitation, we grew two diatoms, Thalassiosira weissflogii and Thalassiosira pseudonana under N starvation conditions and exposed them to high visible light. It showed that the large-sized diatom T. weissflogii can maintain photosynthetic activity for a longer period of time under nitrogen starvation as compared with the small-sized diatom T. pseudonana. The electron transfer reaction was inhibited in both diatoms and the fast closing of reaction centers promoted the development of QB non-reducing PSII centers, thus facilitated the rapid induction of NPQ, however, the induction of NPQ depended on the degree of N starvation. N starvation exacerbated the photoinhibition caused by high light. The smaller-sized T. pseudonana had a higher σi value and was more sensitive to high-light, but its PSII repair rate was also higher. In contrast, T. weissflogii was more tolerant to high light with a lower σi value, but the tolerance was severely reduced under N-starvation. This study provides helpful insight into how climate change variables impact diatom's photosynthetic physiology.
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Affiliation(s)
- Hongjin Qiao
- School of Life Science, Ludong University, Yantai, 264025, China; Key Laboratory of Marine Biotechnology in Universities of Shandong, Ludong University,Yantai, 264025, China
| | - Shasha Zang
- School of Life Science, Ludong University, Yantai, 264025, China; Key Laboratory of Marine Biotechnology in Universities of Shandong, Ludong University,Yantai, 264025, China
| | - Fang Yan
- School of Life Science, Ludong University, Yantai, 264025, China; Key Laboratory of Marine Biotechnology in Universities of Shandong, Ludong University,Yantai, 264025, China
| | - Zhiguang Xu
- School of Life Science, Ludong University, Yantai, 264025, China; Key Laboratory of Marine Biotechnology in Universities of Shandong, Ludong University,Yantai, 264025, China
| | - Lei Wang
- School of Life Science, Ludong University, Yantai, 264025, China; Key Laboratory of Marine Biotechnology in Universities of Shandong, Ludong University,Yantai, 264025, China
| | - Hongyan Wu
- School of Life Science, Ludong University, Yantai, 264025, China; Key Laboratory of Marine Biotechnology in Universities of Shandong, Ludong University,Yantai, 264025, China.
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7
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Thangaraj S, Sun J. Transcriptomic reprogramming of the oceanic diatom Skeletonema dohrnii under warming ocean and acidification. Environ Microbiol 2020; 23:980-995. [PMID: 32975013 DOI: 10.1111/1462-2920.15248] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 09/14/2020] [Accepted: 09/20/2020] [Indexed: 12/19/2022]
Abstract
Under ocean warming and acidification, diatoms use a unique acclimation and adaptation strategy by saving energy and utilizing it for other cellular processes. However, the molecular mechanisms that underlie this reprogramming of energy utilization are currently unknown. Here, we investigate the metabolic reprogramming of the ecologically important diatom Skeletonema dohrnii grown under two different temperature (21°C and 25°C) and pCO2 (400 and 1000 ppm) levels, utilizing global transcriptomic analysis. We find that evolutionary changes in the baseline gene expression, which we termed transcriptional up- and downregulation, is the primary mechanism used by diatoms to acclimate to the combined conditions of ocean warming and acidification. This transcriptional regulation shows that under higher temperature and pCO2 conditions, photosynthesis, electron transport and carboxylation were modified with increasing abundances of genes encoding ATP, NADPH and carbon gaining for the carbon-dioxide-concentrating mechanisms (CCMs). Our results also indicate that changes in the transcriptional regulation of CCMs led to a decrease in the metabolic cost to save energy by promoting amino acid synthesis and nitrogen assimilation for the active protein processing machinery to adapt to warming and ocean acidification. This study generated unique metabolic insights into diatoms and suggests that future climate change conditions will cause evolutionary changes in oceanic diatoms that will facilitate their acclimation strategy.
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Affiliation(s)
- Satheeswaran Thangaraj
- College of Marine Science and Technology, China University of Geosciences (Wuhan), Wuhan, Hubei, 430074, China
| | - Jun Sun
- College of Marine Science and Technology, China University of Geosciences (Wuhan), Wuhan, Hubei, 430074, China
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Yuasa K, Shikata T, Kitatsuji S, Yamasaki Y, Nishiyama Y. Extracellular secretion of superoxide is regulated by photosynthetic electron transport in the noxious red-tide-forming raphidophyte Chattonella antiqua. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2020; 205:111839. [PMID: 32146272 DOI: 10.1016/j.jphotobiol.2020.111839] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 02/11/2020] [Accepted: 02/21/2020] [Indexed: 12/28/2022]
Abstract
The raphidophyte Chattonella antiqua is a noxious red-tide-forming alga that harms fish culture and the aquatic environment. Chattonella antiqua produces and secretes superoxide anions (O2-), and excessive secretion of O2- into the water has been associated with fish mortality. It is known that strong light stimulates the production of O2- in Chattonella spp. but the mechanism of the light-induced production of O2- remains to be clarified. In the present study, we examined the effects of light on extracellular levels of O2- and photosynthesis in C. antiqua. Extracellular levels of O2- rose during growth under high-intensity light, and the level of O2- was correlated with the photosynthetic parameter qP, which reflects the rate of transport of electrons downstream of photosystem II. The production of O2- was inhibited in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea, an inhibitor of photosynthetic electron transport, suggesting that reducing power derived from electron transport might be required for the production of O2-. By contrast, the production of O2- was enhanced in the presence of glycolaldehyde, an inhibitor of the Calvin-Benson cycle, suggesting that the accumulation of NADPH might stimulate the production of O2-. Thus, it is likely that the production of O2- is regulated by photosynthesis in C. antiqua.
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Affiliation(s)
- Koki Yuasa
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570, Japan
| | - Tomoyuki Shikata
- National Research Institute of Fisheries and Environment of Inland Sea, Fisheries Research and Education Agency, 2-17-5 Maruishi, Hatsukaichi, Hiroshima 738-8635, Japan
| | - Saho Kitatsuji
- National Research Institute of Fisheries and Environment of Inland Sea, Fisheries Research and Education Agency, 2-17-5 Maruishi, Hatsukaichi, Hiroshima 738-8635, Japan
| | - Yasuhiro Yamasaki
- Department of Applied Aquabiology, National Fisheries University, Fisheries Research and Education Agency, 2-7-1 Nagatahonmachi, Shimonoseki, Yamaguchi 759-6595, Japan
| | - Yoshitaka Nishiyama
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570, Japan.
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Ma J, Wang W, Liu X, Wang Z, Gao G, Wu H, Li X, Xu J. Zinc toxicity alters the photosynthetic response of red alga Pyropia yezoensis to ocean acidification. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:3202-3212. [PMID: 31838674 DOI: 10.1007/s11356-019-06872-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 10/23/2019] [Indexed: 06/10/2023]
Abstract
The globally changing environmental climate, ocean acidification, and heavy metal pollution are of increasing concern. However, studies investigating the combined effects of ocean acidification and zinc (Zn) exposure on macroalgae are very scarce. In this study, the photosynthetic performance of the red alga Pyropia yezoensis was examined under three different concentrations of Zn (control, 25 (medium), and 100 (high) μg L-1) and pCO2 (400 (ambient) and 1000 (high) μatm). The results showed that higher Zn concentrations resulted in increased toxicity for P. yezoensis, while ocean acidification alleviated this negative effect. Ocean acidification increased the relative growth rate of thalli under both medium and high Zn concentrations. The net photosynthetic rate and respiratory rate of thalli also significantly increased in response under ocean acidification, when thalli were cultured under both medium and high Zn concentrations. Malondialdehyde levels decreased under ocean acidification, compared to ambient CO2 conditions and either medium or high Zn concentrations. The activity of superoxide dismutase increased in response to high Zn concentrations, which was particularly apparent at high Zn concentration and ocean acidification. Immunoblotting tests showed that ocean acidification increased D1 removal, with increasing expression levels of the PSII reaction center proteins D2, CP47, and RbcL. These results suggested that ocean acidification could alleviate the damage caused by Zn exposure, thus providing a theoretical basis for a better prediction of the impact of global climate change and heavy metal contamination on marine primary productivity in the form of seaweeds.
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Affiliation(s)
- Jing Ma
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, No. 59 Cangwu Road, Lianyungang, 222005, Jiangsu, People's Republic of China
| | - Wen Wang
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, No. 59 Cangwu Road, Lianyungang, 222005, Jiangsu, People's Republic of China
| | - Xiaoyan Liu
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, No. 59 Cangwu Road, Lianyungang, 222005, Jiangsu, People's Republic of China
| | - Zhiqin Wang
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, No. 59 Cangwu Road, Lianyungang, 222005, Jiangsu, People's Republic of China
| | - Guang Gao
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, No. 59 Cangwu Road, Lianyungang, 222005, Jiangsu, People's Republic of China
| | - Hailong Wu
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, No. 59 Cangwu Road, Lianyungang, 222005, Jiangsu, People's Republic of China
| | - Xinshu Li
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, No. 59 Cangwu Road, Lianyungang, 222005, Jiangsu, People's Republic of China
| | - Juntian Xu
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, No. 59 Cangwu Road, Lianyungang, 222005, Jiangsu, People's Republic of China.
- Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, No. 59 Cangwu Road, Lianyungang, 222005, Jiangsu, People's Republic of China.
- Co-Innovation Center of Jiangsu Marine Bio-industry Technology, No. 59 Cangwu Road, Lianyungang, 222005, Jiangsu, People's Republic of China.
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Gao G, Wu M, Fu Q, Li X, Xu J. A two-stage model with nitrogen and silicon limitation enhances lipid productivity and biodiesel features of the marine bloom-forming diatom Skeletonema costatum. BIORESOURCE TECHNOLOGY 2019; 289:121717. [PMID: 31279322 DOI: 10.1016/j.biortech.2019.121717] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 06/25/2019] [Accepted: 06/26/2019] [Indexed: 06/09/2023]
Abstract
To enhance biodiesel production and quality from a bloom-forming diatom Skeletonema costatum, a two-stage model, in which cells were cultured in nutrient replete conditions first and then transferred to nutrient limitation conditions, was explored. Compared to one-stage model, nutrient limitation in the second stage significantly increased lipid content in spite of decreasing growth; consequently, Si-limitation and N-Si-limitation respectively increased lipid productivity by 37.6% and 76.7% for 6 h induction, and 42.8% and 113.7% for 12 induction. Nutrient limitation enhanced the proportions of saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) but reduced polyunsaturated fatty acid (PUFA). Therefore, N-Si-limitation reduced iodine value by 33.7% and 45.6% but increased cetane number by 6.4% and 21.6% for 6 and 24 h induction, respectively. These findings indicate that the two-stage model with N-Si-limitation can enhance lipid productivity as well as biodiesel quality from diatoms.
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Affiliation(s)
- Guang Gao
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, Lianyungang 222005, China; State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005, China
| | - Min Wu
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, Lianyungang 222005, China
| | - Qianqian Fu
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, Lianyungang 222005, China
| | - Xinshu Li
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, Lianyungang 222005, China
| | - Juntian Xu
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Lianyungang 222005, China; Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China.
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11
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Gao G, Fu Q, Beardall J, Wu M, Xu J. Combination of ocean acidification and warming enhances the competitive advantage of Skeletonema costatum over a green tide alga, Ulva linza. HARMFUL ALGAE 2019; 85:101698. [PMID: 31810528 DOI: 10.1016/j.hal.2019.101698] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 10/22/2019] [Accepted: 10/23/2019] [Indexed: 06/10/2023]
Abstract
Red tide and green tide are two common algal blooms that frequently occur in many areas in the global oceans. The algae causing red tide and green tide often interact with each other in costal ecosystems. However, little is known on how future CO2-induced ocean acidification combined with temperature variation would affect the interaction of red and green tides. In this study, we cultured the red tide alga Skeletonema costatum and the green tide alga Ulva linza under ambient (400 ppm) and future CO2 (1000 ppm) levels and three temperatures (12, 18, 24 °C) in both monoculture and coculture systems. Coculture did not affect the growth rate of U. linza but significantly decreased it for S. costatum. Elevated CO2 relieved the inhibitory effect of U. linza on the growth of S. costatum, particularly for higher temperatures. At elevated CO2, higher temperature increased the growth rate of S. costatum but reduced it for U. linza. Coculture with U. linza reduced the net photosynthetic rate of S. costatum, which was relieved by elevated CO2. This pattern was also found in Chl a content, indicating that U. linza may inhibit growth of S. costatum via harming pigment synthesis and thus photosynthesis. In monoculture, higher temperature did not affect respiration rate of S. costatum but increased it in U. linza. Coculture did not affect respiration of U. linza but stimulated it for S. costatum, which was a signal of responding to biotic and/abiotic stress. The increased growth of S. costatum at higher temperature and decreased inhibition of U. linza on S. costatum at elevated CO2 suggest that red tides may have more advantages over green tides in future warmer and CO2-enriched oceans.
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Affiliation(s)
- Guang Gao
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, Lianyungang, 222005, China; State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361005, China
| | - Qianqian Fu
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, Lianyungang, 222005, China
| | - John Beardall
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Min Wu
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, Lianyungang, 222005, China
| | - Juntian Xu
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, Lianyungang, 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Lianyungang 222005, China; Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China.
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