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Shen M, Chen X, Wu C, Song Z, Shi J, Liu S, Zhao Y. A microfluidic impedance cytometry device for robust identification of H. pluvialis. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2024; 16:5684-5691. [PMID: 39129414 DOI: 10.1039/d4ay00845f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
H. pluvialis contains rich oleic acid and astaxanthin, which have important applications in the fields of biodiesel and biomedicine. Detection of live H. pluvialis is the prerequisite to obtaining oleic acid and astaxanthin. For this purpose, we successfully developed a reliable microfluidic impedance cytometry for the identification of live H. pluvialis. Firstly, we established a simulation model for detecting H. pluvialis based on their morphology and studied the effect of medium conductivity on the impedance of H. pluvialis at different frequencies. From the simulations, we determined that the optimal solution conductivity for the detection of H. pluvialis was 1500 μS cm-1 and studied the frequency responses of the impedance of H. pluvialis. Secondly, we fabricated the microchannels and stainless-steel detection electrodes and assembled them into microfluidic impedance cytometry. The frequency dependence of live and dead H. pluvialis was explored under different frequencies, and live and dead H. pluvialis were distinguished at a frequency of 1 MHz. The impedance of live H. pluvialis at the frequency of 1 MHz ranges from 33.73 to 52.23 Ω, while that of dead ones ranges from 13.05 to 19.59 Ω. Based on these findings, we accomplished the identification and counting of live H. pluvialis in the live and dead sample solutions. Furthermore, we accomplished the identification and counting of live H. pluvialis in the mixed samples containing Euglena and H. pluvialis. This approach possesses the promising capacity to serve as a robust tool in the identification of target microalgae, addressing a challenge in the fields of biodiesel and biomedicine.
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Affiliation(s)
- Mo Shen
- School of Control Engineering, Northeastern University at Qinhuangdao, Qinhuangdao 066004, PR China.
- Hebei Key Laboratory of Micro-Nano Precision Optical Sensing and Measurement Technology, Qinhuangdao, 066004, PR China
| | - Xiaoming Chen
- School of Control Engineering, Northeastern University at Qinhuangdao, Qinhuangdao 066004, PR China.
- Hebei Key Laboratory of Micro-Nano Precision Optical Sensing and Measurement Technology, Qinhuangdao, 066004, PR China
| | - Chungang Wu
- School of Control Engineering, Northeastern University at Qinhuangdao, Qinhuangdao 066004, PR China.
- Hebei Key Laboratory of Micro-Nano Precision Optical Sensing and Measurement Technology, Qinhuangdao, 066004, PR China
| | - Zhipeng Song
- School of Control Engineering, Northeastern University at Qinhuangdao, Qinhuangdao 066004, PR China.
- Hebei Key Laboratory of Micro-Nano Precision Optical Sensing and Measurement Technology, Qinhuangdao, 066004, PR China
| | - Jishun Shi
- School of Control Engineering, Northeastern University at Qinhuangdao, Qinhuangdao 066004, PR China.
- Hebei Key Laboratory of Micro-Nano Precision Optical Sensing and Measurement Technology, Qinhuangdao, 066004, PR China
| | - Shun Liu
- School of Control Engineering, Northeastern University at Qinhuangdao, Qinhuangdao 066004, PR China.
- Hebei Key Laboratory of Micro-Nano Precision Optical Sensing and Measurement Technology, Qinhuangdao, 066004, PR China
| | - Yong Zhao
- School of Control Engineering, Northeastern University at Qinhuangdao, Qinhuangdao 066004, PR China.
- Hebei Key Laboratory of Micro-Nano Precision Optical Sensing and Measurement Technology, Qinhuangdao, 066004, PR China
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Liu L, Wei D, Huang H, Guo C, Liu J, Hu C, Huang J. Effects of polystyrene microplastics on Euglena gracilis: Intracellular distribution and the protozoan transcriptional responses. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2024; 266:106802. [PMID: 38096643 DOI: 10.1016/j.aquatox.2023.106802] [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: 09/04/2023] [Revised: 12/07/2023] [Accepted: 12/10/2023] [Indexed: 01/02/2024]
Abstract
Microplastics (MPs) introduced into aquatic environments inevitably interact with aquatic organisms such as plankton, potentially yielding adverse effects on the aquatic ecosystem. The extent to which MPs can infiltrate planktonic cells and evoke a molecular response remains largely unknown. In the present study, the internalization of fluorescently labeled polystyrene (PS) MPs on Euglena gracilis cells was investigated, determining the transcriptional responses within protozoa after an 8-day exposure period. The results showed that exposure to 25 mg/L PS-MPs for 8 days, significantly inhibited protozoan growth (P < 0.05) and decreased the chlorophyll a content of E. gracilis. The photosynthetic efficiency of E. gracilis was suppressed by MPs after 4 days, and then recovered to control values by the eighth day. Fluorescence imaging confirmed the presence of MPs in E. gracilis. Transcriptomic analysis revealed the influence of PS-MPs on a diverse range of transcriptional processes, encompassing oxidative phosphorylation, oxidation-reduction process, photosynthesis, and antioxidant enzymes. Notably, a majority of the differentially expressed genes (DEGs) exhibited down-regulation. Furthermore, PS-MPs disturbed the transcriptional regulation of chloroplasts and photosynthesis. These findings indicate a direct interaction between PS-MPs and organelles within E. gracilis cells following internalization, thereby disrupting regular gene expression patterns and posing a substantial environmental risk to the aquatic ecosystem.
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Affiliation(s)
- Li Liu
- College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing 314001, PR China
| | - Dong Wei
- College of Life Science, Linyi University, Linyi 276000, PR China
| | - Hong Huang
- College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing 314001, PR China
| | - Canyang Guo
- College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing 314001, PR China
| | - Juan Liu
- College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing 314001, PR China.
| | - Changwei Hu
- College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing 314001, PR China
| | - Jiaying Huang
- College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing 314001, PR China
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Feng L, Wang Z, Jia D, Zou X, Rao M, Huang Z, Kuang C, Ye J, Chen C, Huang C, Zhang M, Cheng J. Functional metabolism pathways of significantly regulated genes in Nannochloropsis oceanica with various nitrogen/phosphorus nutrients for CO 2 fixation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 883:163318. [PMID: 37030370 DOI: 10.1016/j.scitotenv.2023.163318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 03/16/2023] [Accepted: 04/02/2023] [Indexed: 06/03/2023]
Abstract
To determine the optimal CO2 concentration for microalgal biomass cultivated with industrial flue gas and improve carbon fixation capacity and biomass production. Functional metabolism pathways of significantly regulated genes in Nannochloropsis oceanica (N. oceanica) with various nitrogen/phosphorus (N/P) nutrients for CO2 fixation were comprehensively clarified. At 100 % N/P nutrients, the optimum CO2 concentration was 70 % and the maximum biomass production of microalgae was 1.57 g/L. The optimum CO2 concentration was 50 % for N or P deficiency and 30 % for both N and P deficiency. The optimal combination of CO2 concentration and N/P nutrients caused significant up regulation of proteins related to photosynthesis and cellular respiration in the microalgae, enhancing photosynthetic electron transfer efficiency and carbon metabolism. Microalgal cells with P deficiency and optimal CO2 concentration expressed many phosphate transporter proteins to enhance P metabolism and N metabolism to maintain a high carbon fixation capacity. However, inappropriate combination of N/P nutrients and CO2 concentrations caused more errors in DNA replication and protein synthesis, generating more lysosomes and phagosomes. This inhibited carbon fixation and biomass production in the microalgae with increased cell apoptosis.
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Affiliation(s)
- Lingchong Feng
- State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, Zhejiang, China
| | - Zhenyi Wang
- State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, Zhejiang, China
| | - Dongwei Jia
- State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, Zhejiang, China
| | - Xiangbo Zou
- Guangdong Energy Group Science and Technology Research Institute Co. Ltd., Guangzhou 510630, China
| | - Mumin Rao
- Guangdong Energy Group Science and Technology Research Institute Co. Ltd., Guangzhou 510630, China
| | - Zhimin Huang
- Guangdong Yudean Zhanjiang Biomass Power Co., Ltd., Zhanjiang 524300, China
| | - Cao Kuang
- Guangdong Energy Group Science and Technology Research Institute Co. Ltd., Guangzhou 510630, China
| | - Ji Ye
- Guangdong Energy Group Science and Technology Research Institute Co. Ltd., Guangzhou 510630, China
| | - Chuangting Chen
- Guangdong Energy Group Science and Technology Research Institute Co. Ltd., Guangzhou 510630, China
| | - Cong Huang
- Guangdong Yudean Zhanjiang Biomass Power Co., Ltd., Zhanjiang 524300, China
| | - Maoqiang Zhang
- Guangdong Yudean Zhanjiang Biomass Power Co., Ltd., Zhanjiang 524300, China
| | - Jun Cheng
- State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, Zhejiang, China; Key Laboratory of Low-grade Energy Utilization Technologies and Systems of Ministry of Education, Chongqing University, Chongqing 400044, China.
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Knowles B, Bonachela JA, Cieslik N, Della Penna A, Diaz B, Baetge N, Behrenfeld MJ, Naumovitz K, Boss E, Graff JR, Halsey KH, Haramaty L, Karp-Boss L, Bidle KD. Altered growth and death in dilution-based viral predation assays. PLoS One 2023; 18:e0288114. [PMID: 37418487 DOI: 10.1371/journal.pone.0288114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 06/20/2023] [Indexed: 07/09/2023] Open
Abstract
Viral lysis of phytoplankton is one of the most common forms of death on Earth. Building on an assay used extensively to assess rates of phytoplankton loss to predation by grazers, lysis rates are increasingly quantified through dilution-based techniques. In this approach, dilution of viruses and hosts are expected to reduce infection rates and thus increase host net growth rates (i.e., accumulation rates). The difference between diluted and undiluted host growth rates is interpreted as a measurable proxy for the rate of viral lytic death. These assays are usually conducted in volumes ≥ 1 L. To increase throughput, we implemented a miniaturized, high-throughput, high-replication, flow cytometric microplate dilution assay to measure viral lysis in environmental samples sourced from a suburban pond and the North Atlantic Ocean. The most notable outcome we observed was a decline in phytoplankton densities that was exacerbated by dilution, instead of the increased growth rates expected from lowered virus-phytoplankton encounters. We sought to explain this counterintuitive outcome using theoretical, environmental, and experimental analyses. Our study shows that, while die-offs could be partly explained by a 'plate effect' due to small incubation volumes and cells adhering to walls, the declines in phytoplankton densities are not volume-dependent. Rather, they are driven by many density- and physiology-dependent effects of dilution on predation pressure, nutrient limitation, and growth, all of which violate the original assumptions of dilution assays. As these effects are volume-independent, these processes likely occur in all dilution assays that our analyses show to be remarkably sensitive to dilution-altered phytoplankton growth and insensitive to actual predation pressure. Incorporating altered growth as well as predation, we present a logical framework that categorizes locations by the relative dominance of these mechanisms, with general applicability to dilution-based assays.
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Affiliation(s)
- Ben Knowles
- Department of Marine and Coastal Science, Rutgers University, New Brunswick, New Jersey, United States of America
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, California, United States of America
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California, United States of America
- Institute for Quantitative and Computational Biosciences, University of California, Los Angeles, Los Angeles, California, United States of America
- Institute of the Environment and Sustainability, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Juan A Bonachela
- Department of Ecology, Evolution, and Natural Resources, Rutgers University, New Brunswick, New Jersey, United States of America
| | - Nick Cieslik
- Department of Marine and Coastal Science, Rutgers University, New Brunswick, New Jersey, United States of America
| | - Alice Della Penna
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
- Institute of Marine Science, University of Auckland, Auckland, New Zealand
| | - Ben Diaz
- Department of Marine and Coastal Science, Rutgers University, New Brunswick, New Jersey, United States of America
| | - Nick Baetge
- Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, California, United States of America
| | - Micheal J Behrenfeld
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America
| | - Karen Naumovitz
- Department of Marine and Coastal Science, Rutgers University, New Brunswick, New Jersey, United States of America
| | - Emmanuel Boss
- School of Marine Sciences, University of Maine, Orono, Maine, United States of America
| | - Jason R Graff
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America
| | - Kimberly H Halsey
- Department of Microbiology, Oregon State University, Corvallis, Oregon, United States of America
| | - Liti Haramaty
- Department of Marine and Coastal Science, Rutgers University, New Brunswick, New Jersey, United States of America
| | - Lee Karp-Boss
- School of Marine Sciences, University of Maine, Orono, Maine, United States of America
| | - Kay D Bidle
- Department of Marine and Coastal Science, Rutgers University, New Brunswick, New Jersey, United States of America
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Lain LR, Kravitz J, Matthews M, Bernard S. Simulated Inherent Optical Properties of Aquatic Particles using The Equivalent Algal Populations (EAP) model. Sci Data 2023; 10:412. [PMID: 37355642 DOI: 10.1038/s41597-023-02310-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 06/13/2023] [Indexed: 06/26/2023] Open
Abstract
Paired measurements of phytoplankton absorption and backscatter, the inherent optical properties central to the interpretation of ocean colour remote sensing data, are notoriously rare. We present a dataset of Chlorophyll a (Chl a) -specific phytoplankton absorption, scatter and backscatter for 17 different phytoplankton groups, derived from first principles using measured in vivo pigment absorption and a well-validated semi-analytical coated sphere model which simulates the full suite of biophysically consistent phytoplankton optical properties. The optical properties of each simulated phytoplankton cell are integrated over an entire size distribution and are provided at high spectral resolution. The model code is additionally included to enable user access to the complete set of wavelength-dependent, angularly resolved volume scattering functions. This optically coherent dataset of hyperspectral optical properties for a set of globally significant phytoplankton groups has potential for use in algorithm development towards the optimal exploitation of the new age of hyperspectral satellite radiometry.
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Affiliation(s)
| | - Jeremy Kravitz
- Bay Area Environmental Research Institute, Moffett Field, CA, USA
- NASA Ames Research Center, Mountain View, CA, USA
| | | | - Stewart Bernard
- South African National Space Agency, Cape Town, South Africa
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Fluctuation of growth and photosynthetic characteristics in Prorocentrum shikokuense under phosphorus limitation: Evidence from field and laboratory. Ecol Modell 2023. [DOI: 10.1016/j.ecolmodel.2023.110310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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7
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Liang J, Li Y, Xie P, Liu C, Yu L, Ma X. Dualistic effects of bisphenol A on growth, photosynthetic and oxidative stress of duckweed (Lemna minor). ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:87717-87729. [PMID: 35819675 DOI: 10.1007/s11356-022-21785-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 06/28/2022] [Indexed: 06/15/2023]
Abstract
In this study, we exposed duckweed (Lemna minor), a floating freshwater plant, to BPA at different concentrations (0, 1, 5, 20, and 50 mg/L) for 7 days so as to investigate the effects of BPA on its growth, photosynthesis, antioxidant system, and osmotic substances. It was found that BPA had the acute toxic effects of "low promotion and high inhibition" on growth and photosynthesis. Specifically, BPA at a low concentration (5 mg/L) significantly promoted the plant growth and improved the concentration of photosynthetic pigments (chlorophyll a, b, and total Chl ) of L. minor. However, BPA at a high concentration (50 mg/L) significantly inhibited the plant growth, the Chl content, and the maximal photochemical efficiency (Fv/Fm). Furthermore, BPA with high concentration (50 mg/L) induced ROS accumulation and increased the activities of antioxidant enzymes (SOD, CAT, POD, APX, and GR) and the contents of antioxidant substances (GSH, proline, and T-AOC), which indicated that L. minor might tolerate BPA toxicity by activating an antioxidant defense system. The correlation analysis revealed that the fresh weight of L. minor was significantly and positively correlated with photosynthesis and the contents of soluble protein and sugar, while it was negatively correlated with the content of H2O2. Totally, these results showed that BPA at different concentrations had dualistic effects on the growth of L. minor, which was attributed to the alterations of photosynthesis, oxidative stress, and osmotic regulation systems and provided a novel insight for studying the effects of BPA on aquatic plant physiology.
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Affiliation(s)
- Jiefeng Liang
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
- Sino-Danish College, University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Yu Li
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China
| | - Peng Xie
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China
| | - Chunsheng Liu
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China
- Engineering Research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan, 430070, China
| | - Liqin Yu
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China.
- Engineering Research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan, 430070, China.
| | - Xufa Ma
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China
- Engineering Research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan, 430070, China
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Nagi GK, Corcoran AA, Mandal S. Application of fluorescent transients to indicate nutrient deficiencies in a microalga Nannochloropsis oceanica. ALGAL RES 2022. [DOI: 10.1016/j.algal.2022.102947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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9
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Estimating Biomass and Vitality of Microalgae for Monitoring Cultures: A Roadmap for Reliable Measurements. Cells 2022; 11:cells11152455. [PMID: 35954299 PMCID: PMC9368473 DOI: 10.3390/cells11152455] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 07/31/2022] [Accepted: 08/02/2022] [Indexed: 11/25/2022] Open
Abstract
Estimating algal biomass is a prerequisite for monitoring growth of microalgae. Especially for large-scale production sites, the measurements must be robust, reliable, fast and easy to obtain. We compare the relevant parameters, discuss potential hurdles and provide recommendations to tackle these issues. The focus is on optical density and in vivo autofluorescence of chlorophyll, which have proven to be ideal candidates for monitoring purposes. Beyond biomass, cell vitality is also crucial for maintaining cultures. While maximizing biomass yield is often the primary consideration, some applications require adverse growth conditions for the synthesis of high-quality compounds. The non-invasive technique of pulse-amplified modulated (PAM) fluorescence measurements provides an ideal tool and is increasingly being employed due to ever more affordable devices. We compared three devices and studied the robustness of the dark fluorescence yield of photosystem II (Fv/Fm) at various cell densities. Although the so-called inner filter effects influence the fluorescence signal, the resulting Fv/Fm remain stable and robust over a wide range of cell densities due to mutual effects.
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Interspecific Interactions Drive Nonribosomal Peptide Production in Nodularia spumigena. Appl Environ Microbiol 2022; 88:e0096622. [PMID: 35862669 PMCID: PMC9361812 DOI: 10.1128/aem.00966-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Nodularia spumigena is a bloom-forming cyanobacterium that produces several classes of nonribosomal peptides (NRPs) that are biologically active; however, the ecological roles of specific NRPs remain largely unknown. Here, we explored the involvement of NRPs produced by N. spumigena in interspecific interactions by coculturing the cyanobacterium and its algal competitors, the diatom Phaeodactylum tricornutum and the cryptomonad Rhodomonas salina, and measuring NRP levels and growth responses in all three species. Contrary to the expected growth suppression in the algae, it was N. spumigena that was adversely affected by the diatom, while the cryptomonad had no effect. Reciprocal effects of N. spumigena on the algae were manifested as the prolonged lag phase in R. salina and growth stimulation in P. tricornutum; however, these responses were largely attributed to elevated pH and not to specific NRPs. Nevertheless, the NRP levels in the cocultures were significantly higher than in the monocultures, with an up to 5-fold upregulation of cell-bound nodularins and exudation of nodularin and anabaenopeptin. Thus, chemically mediated interspecific interactions can promote NRP production and release by cyanobacteria, resulting in increased input of these compounds into the water. IMPORTANCE NRPs were involved in growth responses of both cyanobacteria and algae; however, the primary driver of the growth trajectories was high pH induced by N. spumigena. Thus, the pH-mediated inhibition of eukaryotic phytoplankton may be involved in the bloom formation of N. spumigena. We also report, for the first time, the reciprocal growth inhibition of N. spumigena by diatoms resistant to alkaline conditions. As all species in this study can co-occur in the Baltic Sea during summer, these findings are highly relevant for understanding ecological interactions in planktonic communities in this and other systems experiencing regular cyanobacteria blooms.
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Wang J, Wagner ND, Fulton JM, Scott JT. Dynamic Phycobilin Pigment Variations in Diazotrophic and Non-diazotrophic Cyanobacteria Batch Cultures Under Different Initial Nitrogen Concentrations. Front Microbiol 2022; 13:850997. [PMID: 35722313 PMCID: PMC9201475 DOI: 10.3389/fmicb.2022.850997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 04/26/2022] [Indexed: 11/15/2022] Open
Abstract
Increased anthropogenic nutrient loading has led to eutrophication of aquatic ecosystems, which is the major cause of harmful cyanobacteria blooms. Element stoichiometry of cyanobacteria bloom is subject to nutrient availabilities and may significantly contribute to primary production and biogeochemical cycling. Phycobilisome is the antenna of the photosynthetic pigment apparatus in cyanobacteria, which contains phycobilin pigments (PBPs) and linker proteins. This nitrogen (N)-rich protein complex has the potential to support growth as a N-storage site and may play a major role in the variability of cyanobacteria N stoichiometry. However, the regulation of PBPs during bloom formation remains unclear. We investigated the temporal variation of N allocation into PBPs and element stoichiometry for two ubiquitous cyanobacteria species, Microcystis aeruginosa and Dolichospermum flos-aquae, in a batch culture experiment with different initial N availabilities. Our results indicated that the N allocation into PBPs is species-dependent and tightly regulated by the availability of nutrients fueling population expansion. During the batch culture experiment, different nutrient uptake rates led to distinct stoichiometric imbalances of N and phosphorus (P), which substantially altered cyanobacteria C: N and C: P stoichiometry. Microcystis invested cellular N into PBPs and exhibited greater flexibility in C: N and C: P stoichiometry than D. flos-aquae. The dynamics of such N-rich macromolecules may help explain the N stoichiometry variation during a bloom and the interspecific difference between M. aeruginosa and D. flos-aquae. Our study provides a quantitative understanding of the elemental stoichiometry and the regulation of PBPs for non-diazotrophic and diazotrophic cyanobacteria blooms.
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Affiliation(s)
- Jingyu Wang
- The Institute of Ecological, Earth & Environmental Sciences, Baylor University, Waco, TX, United States
- *Correspondence: Jingyu Wang,
| | - Nicole D. Wagner
- Center for Reservoir and Aquatic Systems Research, Baylor University, Waco, TX, United States
| | - James M. Fulton
- Department of Geosciences, Baylor University, Waco, TX, United States
| | - J. Thad Scott
- The Institute of Ecological, Earth & Environmental Sciences, Baylor University, Waco, TX, United States
- Center for Reservoir and Aquatic Systems Research, Baylor University, Waco, TX, United States
- Department of Biology, Baylor University, Waco, TX, United States
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Xiong S, Wang Y, Chen Y, Gao M, Zhao Y, Wu L. Effects of Drought Stress and Rehydration on Physiological and Biochemical Properties of Four Oak Species in China. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11050679. [PMID: 35270149 PMCID: PMC8912384 DOI: 10.3390/plants11050679] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 02/23/2022] [Accepted: 02/28/2022] [Indexed: 05/27/2023]
Abstract
Quercus fabri Hance, Quercus serrata Thunb, Quercus acutissima Carruth, and Quercus variabilis BL are four Chinese oak species commonly used for forestation. To ensure the survival of seedlings, we first need to understand the differences in drought resistance of the four oak species at the seedling stage, and comprehensively evaluate their drought resistance capabilities. The four oak seedlings were divided into drought-rewatering treatment group and well watered samples (control group). For the seedlings of the drought-rewatering treatment group, drought stress lasting 31 days was used, and then re-watering for 5 days. The water parameters, osmotic solutes content, antioxidant enzyme activity and photosynthesis parameters of the seedlings in the two groups were measured every 5 days. Compared with the control group, the relative water content, water potential, net photosynthetic rate, transpiration rate, and stomatal conductance levels of the four oaks all showed a downward trend under continuous drought stress, and showed an upward trend after rehydration. The soluble protein, soluble sugar, proline, peroxidase, superoxide dismutase and catalase content of the four oaks increased first and then decreased under drought stress, and then increased after rehydration. The content of glycine betaine and malondialdehyde continued to increase, and gradually decreased after rehydration. The weight of each index was calculated by principal component analysis, and then the comprehensive evaluation of each index was carried out through the membership function method. The drought resistance levels of the four oak species were as follows: Q. serrata > Q. fabri > Q. variabilis > Q. acutissima.
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Affiliation(s)
- Shifa Xiong
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100091, China; (S.X.); (Y.W.); (Y.C.); (M.G.); (Y.Z.)
- Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
| | - Yangdong Wang
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100091, China; (S.X.); (Y.W.); (Y.C.); (M.G.); (Y.Z.)
- Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
| | - Yicun Chen
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100091, China; (S.X.); (Y.W.); (Y.C.); (M.G.); (Y.Z.)
- Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
| | - Ming Gao
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100091, China; (S.X.); (Y.W.); (Y.C.); (M.G.); (Y.Z.)
- Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
| | - Yunxiao Zhao
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100091, China; (S.X.); (Y.W.); (Y.C.); (M.G.); (Y.Z.)
- Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
| | - Liwen Wu
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100091, China; (S.X.); (Y.W.); (Y.C.); (M.G.); (Y.Z.)
- Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
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13
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Abinandan S, Venkateswarlu K, Megharaj M. Phenotypic changes in microalgae at acidic pH mediate their tolerance to higher concentrations of transition metals. CURRENT RESEARCH IN MICROBIAL SCIENCES 2022; 2:100081. [PMID: 35028626 PMCID: PMC8714768 DOI: 10.1016/j.crmicr.2021.100081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 10/22/2021] [Accepted: 11/06/2021] [Indexed: 11/25/2022] Open
Abstract
Acid-tolerant microalgae were grown at pH 3.5 and 6.7 in presence of heavy metals (HMs). HMs-induced phenotypic changes in microalgae were evaluated by ATR-FTIR spectroscopy. Higher HMs bioavailability affected microalgae more at pH 6.7 than pH 3.5. Acclimation of microalgal strains to acidic pH significantly alleviates HMs toxicity.
Acclimatory phenotypic response is a common phenomenon in microalgae, particularly during heavy metal stress. It is not clear so far whether acclimating to one abiotic stressor can alleviate the stress imposed by another abiotic factor. The intent of the present study was to demonstrate the implication of acidic pH in effecting phenotypic changes that facilitate microalgal tolerance to biologically excess concentrations of heavy metals. Two microalgal strains, Desmodesmus sp. MAS1 and Heterochlorella sp. MAS3, were exposed to biologically excess concentrations of Cu (0.50 and 1.0 mg L‒1), Fe (5 and 10 mg L‒1), Mn (5 and 10 mg L‒1) and Zn (2, 5 and 10 mg L‒1) supplemented to the culture medium at pH 3.5 and 6.7. Chlorophyll autofluorescence and biochemical fingerprinting using FTIR-spectroscopy were used to assess the microalgal strains for phenotypic changes that mediate tolerance to metals. Both the strains responded to acidic pH by effecting differential changes in biochemicals such as carbohydrates, proteins, and lipids. Both the microalgal strains, when acclimated to low pH of 3.5, exhibited an increase in protein (< 2-fold) and lipid (> 1.5-fold). Strain MAS1 grown at pH 3.5 showed a reduction (1.5-fold) in carbohydrates while strain MAS3 exhibited a 17-fold increase in carbohydrates as compared to their growth at pH 6.7. However, lower levels of biologically excess concentrations of the selected transition metals at pH 6.7 unveiled positive or no effect on physiology and biochemistry in microalgal strains, whereas growth with higher metal concentrations at this pH resulted in decreased chlorophyll content. Although the bioavailability of free-metal ions is higher at pH 3.5, as revealed by Visual MINTEQ model, no adverse effect was observed on chlorophyll content in cells grown at pH 3.5 than at pH 6.7. Furthermore, increasing concentrations of Fe, Mn and Zn significantly upregulated the carbohydrate metabolism, but not protein and lipid synthesis, in both strains at pH 3.5 as compared to their growth at pH 6.7. Overall, the impact of pH 3.5 on growth response suggested that acclimation of microalgal strains to acidic pH alleviates metal toxicity by triggering physiological and biochemical changes in microalgae for their survival.
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Affiliation(s)
- Sudharsanam Abinandan
- Global Centre for Environmental Remediation (GCER), College of Engineering, Science and Environment, The University of Newcastle, ATC Building, University Drive, Callaghan, NSW 2308, Australia
| | - Kadiyala Venkateswarlu
- Formerly Department of Microbiology, Sri Krishnadevaraya University, Anantapuramu, 515003, India
| | - Mallavarapu Megharaj
- Global Centre for Environmental Remediation (GCER), College of Engineering, Science and Environment, The University of Newcastle, ATC Building, University Drive, Callaghan, NSW 2308, Australia
- Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), The University of Newcastle, Callaghan, NSW 2308, Australia
- Corresponding author at: Global Centre for Environmental Remediation (GCER), College of Engineering, Science and Environment, The University of Newcastle, ATC Building, University Drive, Callaghan, NSW 2308, Australia.
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14
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Duarte Ferreira G, Romano F, Medić N, Pitta P, Hansen PJ, Flynn KJ, Mitra A, Calbet A. Mixoplankton interferences in dilution grazing experiments. Sci Rep 2021; 11:23849. [PMID: 34903787 PMCID: PMC8668877 DOI: 10.1038/s41598-021-03176-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 11/29/2021] [Indexed: 11/09/2022] Open
Abstract
It remains unclear as to how mixoplankton (coupled phototrophy and phagotrophy in one cell) affects the estimation of grazing rates obtained from the widely used dilution grazing technique. To address this issue, we prepared laboratory-controlled dilution experiments with known mixtures of phyto-, protozoo-, and mixoplankton, operated under different light regimes and species combinations. Our results evidenced that chlorophyll is an inadequate proxy for phytoplankton when mixoplankton are present. Conversely, species-specific cellular counts could assist (although not fully solve) in the integration of mixoplanktonic activity in a dilution experiment. Moreover, cell counts can expose prey selectivity patterns and intraguild interactions among grazers. Our results also demonstrated that whole community approaches mimic reality better than single-species laboratory experiments. We also confirmed that light is required for protozoo- and mixoplankton to correctly express their feeding activity, and that overall diurnal grazing is higher than nocturnal. Thus, we recommend that a detailed examination of initial and final plankton communities should become routine in dilution experiments, and that incubations should preferably be started at the beginning of both day and night periods. Finally, we hypothesize that in silico approaches may help disentangle the contribution of mixoplankton to the community grazing of a given system.
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Affiliation(s)
- Guilherme Duarte Ferreira
- Institut de Ciències del Mar, CSIC, Pg. Marítim de la Barceloneta, 37-49, 08003, Barcelona, Spain. .,Marine Biological Section, University of Copenhagen, 3000, Helsingør, Denmark.
| | - Filomena Romano
- Marine Biological Section, University of Copenhagen, 3000, Helsingør, Denmark.,Institute of Oceanography, Hellenic Centre for Marine Research, PO Box 2214, 71003, Heraklion, Greece
| | - Nikola Medić
- Marine Biological Section, University of Copenhagen, 3000, Helsingør, Denmark
| | - Paraskevi Pitta
- Institute of Oceanography, Hellenic Centre for Marine Research, PO Box 2214, 71003, Heraklion, Greece
| | - Per Juel Hansen
- Marine Biological Section, University of Copenhagen, 3000, Helsingør, Denmark
| | - Kevin J Flynn
- Plymouth Marine Laboratory, Prospect Place, Plymouth, PL1 3DH, UK
| | - Aditee Mitra
- School of Earth and Environmental Sciences, Cardiff University, Park Place, Cardiff, CF10 3AT, UK
| | - Albert Calbet
- Institut de Ciències del Mar, CSIC, Pg. Marítim de la Barceloneta, 37-49, 08003, Barcelona, Spain
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15
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Mogany T, Bhola V, Ramanna L, Bux F. Photosynthesis and pigment production: elucidation of the interactive effects of nutrients and light on Chlamydomonas reinhardtii. Bioprocess Biosyst Eng 2021; 45:187-201. [PMID: 34668053 DOI: 10.1007/s00449-021-02651-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 09/30/2021] [Indexed: 01/22/2023]
Abstract
Chlamydomonas reinhardtii produces a variety of compounds that can be beneficial to human and animal health. Among these compounds, application of photosynthetic pigments, such as chlorophylls and carotenoids, has gained considerable interest in numerous industries. A better understanding on the interactive effects of essential nutrients and light on microalgal physiology and pigment production would be beneficial in improving cultivation strategies. Therefore, this study evaluated biomass, carotenoid and chlorophyll yield and the following fluorescence parameters: quantum yield in PS II [Y(II)] and electron transport rate (ETR) using response surface methodology (RSM). The Fv/Fm, Y(NO) and Y(NPQ) were also monitored; however, no significant relationship was observed. From the investigation it was apparent that nitrogen and carbon; as well as the interactive effects of (nitrogen and carbon) and (carbon and light irradiance) were significant factors. The model predicted the optimum conditions for maximum carotenoids (8.15 ± 0.389 mg g-1) were 08.7 mol l-1 of nitrogen, 0.2 mol l-1 and 50 μmol photon m-2 s-1 of light irradiance. While maximum chlorophyll (33.6 ± 0.854 mg g-1) required a higher nitrogen (11.21 mol l-1). The photosynthetic parameters [Y(II), ETR] was correlated with the primary pigments and biomass production. Increased photosynthetic activity was associated with high carbon and light. The Y(II)and ETR of PSII under these conditions were 0.2 and ~ 14, respectively. This approach was accurate in developing the model, optimizing factors and analysing interaction effects. This study served to provide a better understanding on the interactions between factors influencing pigment biosynthesis and photosynthetic performance of Chlamydomonas reinhardtii.
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Affiliation(s)
- Trisha Mogany
- Institute for Water and Wastewater Technology, Durban University of Technology, Durban, 4001, South Africa
| | - Virthie Bhola
- Institute for Water and Wastewater Technology, Durban University of Technology, Durban, 4001, South Africa
| | - Luveshan Ramanna
- Institute for Water and Wastewater Technology, Durban University of Technology, Durban, 4001, South Africa
| | - Faizal Bux
- Institute for Water and Wastewater Technology, Durban University of Technology, Durban, 4001, South Africa.
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16
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Chen H, Li K, Xue C, Wang Q. A Novel Method for Non-invasive Estimation of Primary Productivity in Aquatic Ecosystems Using a Chlorophyll Fluorescence-Induced Dynamic Curve. Front Microbiol 2021; 12:682250. [PMID: 34194414 PMCID: PMC8236984 DOI: 10.3389/fmicb.2021.682250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 05/10/2021] [Indexed: 11/13/2022] Open
Abstract
Photosynthetic microalgae are a major contributor to primary productivity in aquatic ecosystems, but typical measurements of their biomass and productivity are costly and relatively inefficient. The chlorophyll fluorescence induced dynamic (OJIP) curve can reflect the original photochemical reaction and the changes to the function and structure of photosystems as well as the effects of environmental factors on photosynthetic systems. Here, we present a novel method for estimating the Chl a content and photosynthetic microalgal cell density in water samples using the integral area of the OJIP curve. We identify strong linear relationships between OJIP curve integrals and both Chl a contents and cell densities for a variety of microalgal cultures and natural communities. Based on these findings, we present a non-invasive method to estimate primary productivity in aquatic ecosystems and monitor microalgal populations. We believe that this technique will allow for widespread, rapid, and inexpensive estimating of water primary productivity and monitoring of microalgal populations in natural water. This method is potentially useful in health assessment of natural water and as an early warning indicator for algal blooms.
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Affiliation(s)
- Hui Chen
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
| | - Kunfeng Li
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Chunling Xue
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Qiang Wang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
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17
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Lage S, Mazur-Marzec H, Gorokhova E. Competitive interactions as a mechanism for chemical diversity maintenance in Nodularia spumigena. Sci Rep 2021; 11:8970. [PMID: 33903638 PMCID: PMC8076297 DOI: 10.1038/s41598-021-88361-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 04/12/2021] [Indexed: 02/06/2023] Open
Abstract
Nodularia spumigena is a bloom-forming diazotrophic cyanobacterium inhabiting brackish waters worldwide. This species produces non-ribosomal peptides (NRPs), including the hepatotoxin nodularin, often referred to as cyanotoxin. Several known classes of NRPs have various biological activities, although their modes of action are poorly understood. In the Baltic N. spumigena, there is a high NRP chemodiversity among strains, allowing their grouping in specific chemotypes and subgroups. Therefore, it is relevant to ask whether the NRP production is affected by intraspecific interactions between the co-existing strains. Using a novel approach that combines culture technique and liquid chromatography-tandem mass spectrometry for the NRP analysis, we examined N. spumigena strains under mono- and co-culture conditions. The test strains were selected to represent N. spumigena belonging to the same or different chemotype subgroups. In this setup, we observed physiological and metabolic responses in the test strains grown without cell contact. The changes in NRP levels to co-culture conditions were conserved within a chemotype subgroup but different between the subgroups. Our results suggest that intraspecific interactions may promote a chemical diversity in N. spumigena population, with higher NRP production compared to a single-strain population. Studying allelochemical signalling in this cyanobacterium is crucial for understanding toxicity mechanisms and plankton community interactions in the Baltic Sea and other aquatic systems experiencing regular blooms.
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Affiliation(s)
- Sandra Lage
- grid.10548.380000 0004 1936 9377Department of Environmental Science, Stockholm University, Stockholm, Sweden ,grid.8585.00000 0001 2370 4076Division of Marine Biotechnology, Institute of Oceanography, University of Gdańsk, Gdynia, Poland
| | - Hanna Mazur-Marzec
- grid.8585.00000 0001 2370 4076Division of Marine Biotechnology, Institute of Oceanography, University of Gdańsk, Gdynia, Poland
| | - Elena Gorokhova
- grid.10548.380000 0004 1936 9377Department of Environmental Science, Stockholm University, Stockholm, Sweden
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18
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Bhagooli R, Mattan-Moorgawa S, Kaullysing D, Louis YD, Gopeechund A, Ramah S, Soondur M, Pilly SS, Beesoo R, Wijayanti DP, Bachok ZB, Monrás VC, Casareto BE, Suzuki Y, Baker AC. Chlorophyll fluorescence - A tool to assess photosynthetic performance and stress photophysiology in symbiotic marine invertebrates and seaplants. MARINE POLLUTION BULLETIN 2021; 165:112059. [PMID: 33677415 DOI: 10.1016/j.marpolbul.2021.112059] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 12/30/2020] [Accepted: 01/01/2021] [Indexed: 06/12/2023]
Abstract
Chlorophyll a fluorescence is increasingly being used as a rapid, non-invasive, sensitive and convenient indicator of photosynthetic performance in marine autotrophs. This review presents the methodology, applications and limitations of chlorophyll fluorescence in marine studies. The various chlorophyll fluorescence tools such as Pulse-Amplitude-Modulated (PAM) and Fast Repetition Rate (FRR) fluorometry used in marine scientific studies are discussed. Various commonly employed chlorophyll fluorescence parameters are elaborated. The application of chlorophyll fluorescence in measuring natural variations, stress, stress tolerance and acclimation/adaptation to changing environment in primary producers such as microalgae, macroalgae, seagrasses and mangroves, and marine symbiotic invertebrates, namely symbiotic sponges, hard corals and sea anemones, kleptoplastic sea slugs and giant clams is critically assessed. Stressors include environmental, biological, physical and chemical ones. The strengths, limitations and future perspectives of the use of chlorophyll fluorescence technique as an assessment tool in symbiotic marine organisms and seaplants are discussed.
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Affiliation(s)
- Ranjeet Bhagooli
- Department of Biosciences & Ocean Studies, Faculty of Science & Pole of Research Excellence, Sustainable Marine Biodiversity Research Group, University of Mauritius, Réduit 80837, Mauritius; The Biodiversity and Environment Institute, Réduit, Mauritius; The Society of Biology (Mauritius), Réduit, Mauritius; Institute of Oceanography and Environment (INOS), Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia.
| | - Sushma Mattan-Moorgawa
- Department of Biosciences & Ocean Studies, Faculty of Science & Pole of Research Excellence, Sustainable Marine Biodiversity Research Group, University of Mauritius, Réduit 80837, Mauritius; The Biodiversity and Environment Institute, Réduit, Mauritius
| | - Deepeeka Kaullysing
- Department of Biosciences & Ocean Studies, Faculty of Science & Pole of Research Excellence, Sustainable Marine Biodiversity Research Group, University of Mauritius, Réduit 80837, Mauritius; The Biodiversity and Environment Institute, Réduit, Mauritius
| | - Yohan Didier Louis
- Department of Biosciences & Ocean Studies, Faculty of Science & Pole of Research Excellence, Sustainable Marine Biodiversity Research Group, University of Mauritius, Réduit 80837, Mauritius
| | - Arvind Gopeechund
- Department of Biosciences & Ocean Studies, Faculty of Science & Pole of Research Excellence, Sustainable Marine Biodiversity Research Group, University of Mauritius, Réduit 80837, Mauritius; The Biodiversity and Environment Institute, Réduit, Mauritius
| | - Sundy Ramah
- Department of Biosciences & Ocean Studies, Faculty of Science & Pole of Research Excellence, Sustainable Marine Biodiversity Research Group, University of Mauritius, Réduit 80837, Mauritius
| | - Mouneshwar Soondur
- Department of Biosciences & Ocean Studies, Faculty of Science & Pole of Research Excellence, Sustainable Marine Biodiversity Research Group, University of Mauritius, Réduit 80837, Mauritius; The Biodiversity and Environment Institute, Réduit, Mauritius
| | - Sivajyodee Sannassy Pilly
- Department of Biosciences & Ocean Studies, Faculty of Science & Pole of Research Excellence, Sustainable Marine Biodiversity Research Group, University of Mauritius, Réduit 80837, Mauritius
| | - Rima Beesoo
- Department of Biosciences & Ocean Studies, Faculty of Science & Pole of Research Excellence, Sustainable Marine Biodiversity Research Group, University of Mauritius, Réduit 80837, Mauritius
| | | | - Zainudin Bin Bachok
- Institute of Oceanography and Environment (INOS), Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia
| | - Víctor Cubillos Monrás
- Instituto de Ciencias Marinas y Limnológicas, Laboratorio Costero de Recursos Acuáticos de Calfuco, Universidad Austral de Chile, Valdivia, Chile
| | | | - Yoshimi Suzuki
- Shizuoka University, 836 Oya, Suruga, Shizuoka, Shizuoka, Japan
| | - Andrew Charles Baker
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA
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19
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Trade-offs Between Light and Nutrient Availability Across Gradients of Dissolved Organic Carbon Lead to Spatially and Temporally Variable Responses of Lake Phytoplankton Biomass to Browning. Ecosystems 2021. [DOI: 10.1007/s10021-021-00619-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AbstractNorthern lakes are experiencing widespread increases in dissolved organic carbon (DOC) that are likely to lead to changes in pelagic phytoplankton biomass. Pelagic phytoplankton biomass responds to trade-offs between light and nutrient availability. However, the influence of DOC light absorbing properties and carbon–nutrient stoichiometry on phytoplankton biomass across seasonal or spatial gradients has not been assessed. Here, we analyzed data from almost 5000 lakes to examine how the carbon–phytoplankton biomass relationship is influenced by seasonal changes in light availability, DOC light absorbing properties (carbon-specific visual absorbance, SVA420), and DOC–nutrient [total nitrogen (TN) and total phosphorus (TP)] stoichiometry, using TOC as a proxy for DOC. We found evidence for trade-offs between light and nutrient availability in the relationship between DOC and phytoplankton biomass [chlorophyll (chl)-a], with the shape of the relationship varying with season. A clear unimodal relationship was found only in the fall, particularly in the subsets of lakes with the highest TOC:TP. Observed trends of increasing TOC:TP and decreasing TOC:TN suggest that the effects of future browning will be contingent on future changes in carbon–nutrient stoichiometry. If browning continues, phytoplankton biomass will likely increase in most northern lakes, with increases of up to 76% for a 1.7 mg L−1 increase in DOC expected in subarctic regions, where DOC, SVA420, DOC:TN, and DOC:TP are all low. In boreal regions with higher DOC and higher SVA420, and thus lower light availability, lakes may experience only moderate increases or even decreases in phytoplankton biomass with future browning.
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20
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Zhang Y, Gao K. Photosynthesis and calcification of the coccolithophore Emiliania huxleyi are more sensitive to changed levels of light and CO 2 under nutrient limitation. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2021; 217:112145. [PMID: 33735745 DOI: 10.1016/j.jphotobiol.2021.112145] [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: 10/29/2020] [Revised: 01/02/2021] [Accepted: 01/25/2021] [Indexed: 11/18/2022]
Abstract
Photophysiological responses of phytoplankton to changing multiple environmental drivers are essential in understanding and predicting ecological consequences of ocean climate changes. In this study, we investigated the combined effects of two CO2 levels (410 and 925 μatm) and five light intensities (80 to 480 μmol photons m-2 s-1) on cellular pigments contents, photosynthesis and calcification of the coccolithophore Emiliania huxleyi grown under nutrient replete and limited conditions, respectively. Our results showed that high light intensity, high CO2 level and nitrate limitation acted synergistically to reduce cellular chlorophyll a and carotenoid contents. Nitrate limitation predominantly enhanced calcification rate; phosphate limitation predominantly reduced photosynthetic carbon fixation rate, with larger extent of the reduction under higher levels of CO2 and light. Reduced availability of both nitrate and phosphate under the elevated CO2 concentration decreased saturating light levels for the cells to achieve the maximal relative electron transport rate (rETRmax). Light-saturating levels for rETRmax were lower than that for photosynthetic and calcification rates under the nutrient limitation. Regardless of the culture conditions, rETR under growth light levels correlated linearly and positively with measured photosynthetic and calcification rates. Our findings imply that E. huxleyi cells acclimated to macro-nutrient limitation and elevated CO2 concentration decreased their light requirement to achieve the maximal electron transport, photosynthetic and calcification rates, indicating a photophysiological strategy to cope with CO2 rise/pH drop in shoaled upper mixing layer above the thermocline where the microalgal cells are exposed to increased levels of light and decreased levels of nutrients.
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Affiliation(s)
- Yong Zhang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China; College of Environmental Science and Engineering, Fujian Key Laboratory of Pollution Control and Resource Recycling, Fujian Normal University, Fuzhou, China
| | - Kunshan Gao
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China.
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21
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Fernández-González C, Marañón E. Effect of temperature on the unimodal size scaling of phytoplankton growth. Sci Rep 2021; 11:953. [PMID: 33441617 PMCID: PMC7806832 DOI: 10.1038/s41598-020-79616-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 12/10/2020] [Indexed: 11/30/2022] Open
Abstract
Contrary to predictions by the allometric theory, there is evidence that phytoplankton growth rates peak at intermediate cell sizes. However, it is still unknown if this pattern may result from the effect of experimental temperature. Here we test whether temperature affects the unimodal size scaling pattern of phytoplankton growth by (1) growing Synechococcus sp., Ostreococcus tauri, Micromonas commoda and Pavlova lutheri at 18 °C and 25 °C, and (2) using thermal response curves available in the literature to estimate the growth rate at 25 °C as well as the maximum growth rate at optimal temperature for 22 species assayed previously at 18 °C. We also assess the sensitivity of growth rate estimates to the metric employed for measuring standing stocks, by calculating growth rates based on in vivo fluorescence, chlorophyll a concentration, cell abundance and biomass (particulate organic carbon and nitrogen content). Our results show that the unimodal size scaling pattern of phytoplankton growth, with a peak at intermediate cell sizes, is observed at 18 °C, 25 °C and at the optimal temperature for growth, and that it prevails irrespective of the standing-stock metric used. The unimodal size scaling pattern of phytoplankton growth is supported by two independent field observations reported in the literature: (i) a positive relationship between cell size and metabolic rate in the picophytoplankton size range and (ii) the dominance of intermediate-size cells in nutrient-rich waters during blooms.
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Affiliation(s)
- Cristina Fernández-González
- Department of Ecology and Animal Biology, Universidade de Vigo, Vigo, Spain. .,Centro de Investigación Mariña (CIM-UVigo), Vigo, Spain.
| | - Emilio Marañón
- Department of Ecology and Animal Biology, Universidade de Vigo, Vigo, Spain.,Centro de Investigación Mariña (CIM-UVigo), Vigo, Spain
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22
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Luo Z, Wang Z, Liu A, Yan Y, Wu Y, Zhang X. New insights into toxic effects of arsenate on four Microcystis species under different phosphorus regimes. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:44460-44469. [PMID: 32770468 DOI: 10.1007/s11356-020-10396-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 08/03/2020] [Indexed: 06/11/2023]
Abstract
Very little information is available on the stressed growth of Microcystis imposed by arsenate (As(V)) under different phosphorus (P) regimes. In this study, we examined the growth characteristics and arsenic transformation of four Microcystis species exposed under As(V) with two P sources involving dissolved inorganic phosphorus (IP) and organophosphate (D-glucose-6-phosphate disodium salt, GP). Results showed that all the four chosen Microcystis species could grow and reproduce with GP as the only P source, and the difference was insignificant when compared with IP. From optical density (OD), chlorophyll a (Chla), and actual quantum yield (Yield), the tolerance to As(V) of the chosen species was following as FACHB 905 > FACHB 1028 > FACHB 1334 > FACHB 912. Specifically, the 96 h EC50 of As(V) for FACHB 905 in IP was approx. 4 orders of magnitude higher than that in GP, but for other three algal species, the 96 h EC50 values were similar under the two given different P conditions. Furthermore, all antioxidant enzyme activities of superoxide dismutase (SOD), peroxide dismutase (POD), glutathione S-transferases (GSTs), and metalloproteinase (MTs) in algal cells were significantly increased in GP conditions. Moreover, the enzyme activities of AKP, GSTs, and MTs were inhibited with increasing As(V) levels under both IP and GP conditions. In addition, arsenite (As(III)) and methylated As of monomethylarsonic acid (MMA) and dimethylthioarsinic acid (DMA) were found in FACHB 912 and FACHB 1334 media, indicating that these Microcystis could detoxify As(V) by As biotransformation under IP and GP conditions. Specifically, As(V) reduction was elevated in media of FACHB 1334 and FACHB 905, but was decreased in media of FACHB 912 under GP conditions. Our results highlight the different P sources that impact the toxic effects of arsenate exposure on Microcystis and subsequent As biotransformation.
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Affiliation(s)
- Zhuanxi Luo
- College of Chemical Engineering and Fujian Provincial Key Laboratory of Biochemical Technology, Huaqiao University, Xiamen, 361021, China.
- Key Laboratory of Karst Dynamics, MNR & Guangxi, Institute of Karst Geology, CAGS, Guilin, 541004, China.
| | - Zhenhong Wang
- College of Chemistry and Environment and Fujian Province Key Laboratory of Modern Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou, 363000, China
| | - Aifen Liu
- College of Chemistry and Environment and Fujian Province Key Laboratory of Modern Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou, 363000, China
| | - Yu Yan
- College of Chemical Engineering and Fujian Provincial Key Laboratory of Biochemical Technology, Huaqiao University, Xiamen, 361021, China
| | - Yaqing Wu
- Instrumental Analysis Center of Huaqiao University, Xiamen, 361021, China
| | - Xiaoyong Zhang
- Center of Environmental Emergency Response and Accident Investigation of Jiangsu Province, Nanjing, 210036, China
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23
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Temporal and Spatial Variations of the Biochemical Composition of Phytoplankton and Potential Food Material (FM) in Jaran Bay, South Korea. WATER 2020. [DOI: 10.3390/w12113093] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Food material (FM) derived from biochemical components (e.g., proteins, lipids, and carbohydrates) of phytoplankton can provide important quantitative and qualitative information of the food available to filter-feeding animals. The main objective of this study was to observe the seasonal and spatial variations of the biochemical compositions of phytoplankton and to identify the major controlling factors of FM as a primary food source in Jaran Bay, a large shellfish aquaculture site in South Korea. Based on monthly sampling conducted during 2016, significant monthly variations in the depth-integrated concentrations of major inorganic nutrients and chlorophyll a within the euphotic water column and a predominance (49.9 ± 18.7%) of micro-sized phytoplankton (>20 μm) were observed in Jaran Bay. Carbohydrates were the dominant biochemical component (51.8 ± 8.7%), followed by lipids (27.3 ± 3.8%) and proteins (20.9 ± 7.4%), during the study period. The biochemical compositions and average monthly FM levels (411.7 ± 93.0 mg m−3) in Jaran Bay were not consistent among different bays in the southern coastal region of South Korea, possibly due to differences in controlling factors, such as environmental and biological factors. According to the results from multiple linear regression, the variations in FM could be explained by the relatively large phytoplankton and the P* (PO43− − 1/16 × NO3−) and NH4+ concentrations in Jaran Bay. The macromolecular compositions and FM, as alternatives food source materials, should be monitored in Jaran Bay due to recent changes in nutrient concentrations and phytoplankton communities.
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24
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Schuler MS, Hintz WD, Jones DK, Mattes BM, Stoler AB, Relyea RA. The effects of nutrient enrichment and invasive mollusks on freshwater environments. Ecosphere 2020. [DOI: 10.1002/ecs2.3196] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Matthew S. Schuler
- Department of Biological Sciences Darrin Fresh Water Institute Rensselaer Polytechnic Institute Troy New York12180USA
- Department of Biology Montclair State University Montclair New Jersey07043USA
| | - William D. Hintz
- Department of Biological Sciences Darrin Fresh Water Institute Rensselaer Polytechnic Institute Troy New York12180USA
- Department of Environmental Sciences and Lake Erie Center University of Toledo 6200 Bay Shore Rd Oregon Ohio USA
| | - Devin K. Jones
- Department of Biological Sciences Darrin Fresh Water Institute Rensselaer Polytechnic Institute Troy New York12180USA
- Department of Biological Sciences University of Notre Dame Notre Dame Indiana46556USA
| | - Brian M. Mattes
- Department of Biological Sciences Darrin Fresh Water Institute Rensselaer Polytechnic Institute Troy New York12180USA
| | - Aaron B. Stoler
- Department of Biological Sciences Darrin Fresh Water Institute Rensselaer Polytechnic Institute Troy New York12180USA
- School of Natural Sciences and Mathematics Stockton University Galloway New Jersey08205USA
| | - Rick A. Relyea
- Department of Biological Sciences Darrin Fresh Water Institute Rensselaer Polytechnic Institute Troy New York12180USA
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25
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Spatio-Temporal Variability of Chlorophyll-A and Environmental Variables in the Panama Bight. REMOTE SENSING 2020. [DOI: 10.3390/rs12132150] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The analysis of synoptic satellite data of total chlorophyll-a (Chl-a) and the environmental drivers that influence nutrient and light availability for phytoplankton growth allows us to understand the spatio-temporal variability of phytoplankton biomass. In the Panama Bight Tropical region (PB; 1–9°N, 79–84°W), the spatial distribution of Chl-a is mostly related to the seasonal wind patterns and the intensity of localized upwelling centers. However, the association between the Chl-a and different physical variables and nutrient availability is still not fully assessed. In this study, we evaluate the relationship between the Chl-a and multiple physical (wind, Ekman pumping, geostrophic circulation, mixed layer depth, sea level anomalies, river discharges, sea surface temperature, and photosynthetically available radiation) and chemical (nutrients) drivers in order to explain the spatio-temporal Chl-a variability in the PB. We used satellite data of Chl-a and physical variables, and a re-analysis of a biogeochemical product for nutrients (2002–2016). Our results show that at the regional scale, the Chl-a varies seasonally in response to the wind forcing and sea surface temperature. However, in the coastal areas (mainly Gulf of Panama and off central-southern Colombia), the maximum non-seasonal Chl-a values are found in association with the availability of nutrients by river discharges, localized upwelling centers and the geostrophic circulation field. From this study, we infer that the interplay among these physical-chemical drivers is crucial for supporting the phytoplankton growth and the high biodiversity of the PB region.
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26
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Osorio JHM, Benettoni P, Schmidt M, Stryhanyuk H, Schmitt-Jansen M, Pinto G, Pollio A, Frunzo L, Lens PNL, Richnow HH, Esposito G, Musat N. Investigation of architecture development and phosphate distribution in Chlorella biofilm by complementary microscopy techniques. FEMS Microbiol Ecol 2020; 95:5372415. [PMID: 30848779 DOI: 10.1093/femsec/fiz029] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 03/07/2019] [Indexed: 12/12/2022] Open
Abstract
Microalgae biofilms may play an important role in the mitigation and prevention of eutrophication caused by domestic, agricultural and industrial wastewater effluents. Despite their potential, the biofilm development and role in nutrient removal are not well understood. Its clarification requires comprehensive studies of the complex three-dimensional architecture of the biofilm. In this study, we established a multimodal imaging approach to provide key information regarding architecture development and nutrient distribution in the biofilm of two green algae organisms: Chlorella pyrenoidosa and Chlorella vulgaris. Helium ion microscopy (HIM), scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM-EDX) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were employed for i) elucidation of spatial arrangement, ii) elemental mapping and iii) 3D chemical imaging of the biofilm. The fine structure of the algal biofilm was resolved by HIM, the evidence of the accumulation of phosphate in hot spots was provided by SEM-EDX and the localization of phosphate oxides granules throughout the whole sample was clarified by ToF-SIMS. The reported results shed light on the phosphorus distribution during Chlorella's biofilm formation and highlight the potential of such correlative approach to solve fundamental question in algal biotechnology research.
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Affiliation(s)
- Jairo H Moreno Osorio
- Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, via Di Biasio, 43 - 03043 Cassino, Italy.,Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig
| | - Pietro Benettoni
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig
| | - Matthias Schmidt
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig
| | - Hryhoriy Stryhanyuk
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig
| | - Mechthild Schmitt-Jansen
- Department of Bioanalytical Ecotoxicology, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig
| | - Gabriele Pinto
- Department of Biology, University of Naples "Federico II", via Cintia - Complex Monte S. Angelo, 26. 80126 Naples, Italy
| | - Antonino Pollio
- Department of Biology, University of Naples "Federico II", via Cintia - Complex Monte S. Angelo, 26. 80126 Naples, Italy
| | - Luigi Frunzo
- Department of Mathematics and Applications Renato Caccioppoli, University of Naples "Federico II" via Cintia, Monte S. Angelo, 80126 Naples, Italy
| | - Piet N L Lens
- UNESCO-IHE institute for water education, Westvest 7, 2611AX Delft, The Netherlands.,National University of Ireland Galway, University Road, Galway H91 TK33, Ireland
| | - Hans H Richnow
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig
| | - Giovanni Esposito
- Department of Civil, Architectural and Environmental Engineering, University of Naples "Federico II" via Claudio 21, 80125 Naples, Italy
| | - Niculina Musat
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig
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27
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Beaulieu M, Cabana H, Huot Y. Adverse effects of atrazine, DCMU and metolachlor on phytoplankton cultures and communities at environmentally relevant concentrations using Fast Repetition Rate Fluorescence. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 712:136239. [PMID: 31931192 DOI: 10.1016/j.scitotenv.2019.136239] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 12/17/2019] [Accepted: 12/18/2019] [Indexed: 06/10/2023]
Abstract
The widespread and persistent contamination of freshwater environments by low concentrations of pesticides is a growing concern worldwide. In aquatic environments, herbicide pollution is of greatest concern for phytoplankton, due to their similarities to terrestrial plants. Through the use of Fast Repetition Rate Fluorometry (FRRF) during weeklong experiments on 10 phytoplankton cultures from 4 classes and 4 natural communities, we demonstrate that PSII-inhibiting herbicides, notably atrazine that is extensively used in North America, consistently have effects on freshwater phytoplankton photophysiology at concentrations far below concentrations affecting the most sensitive species in previous studies. The parameters specific to FRRF (Ρ, σ, τ1, τ2, τ3) were those most sensitive to PSII inhibitors, compared to the standard fluorescence parameters derived from other fluorescence protocols such as Pulse Amplitude Modulation (PAM) fluorometry (F0, Fm, Fv/Fm) and extracted chlorophyll a concentrations. Based on these findings, existing national environmental guidelines and standards are insufficient to adequately prevent adverse effects of atrazine and other PSII inhibiting herbicides on algal physiology in aquatic ecosystems.
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Affiliation(s)
- Marieke Beaulieu
- Department of Civil Engineering, Université de Sherbrooke, Canada.
| | - Hubert Cabana
- Department of Civil Engineering, Université de Sherbrooke, Canada.
| | - Yannick Huot
- Department of Geomatics, Université de Sherbrooke, Canada.
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28
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Vidyarathna NK, Papke E, Coyne KJ, Cohen JH, Warner ME. Functional trait thermal acclimation differs across three species of mid-Atlantic harmful algae. HARMFUL ALGAE 2020; 94:101804. [PMID: 32414505 DOI: 10.1016/j.hal.2020.101804] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 03/05/2020] [Accepted: 04/04/2020] [Indexed: 06/11/2023]
Abstract
Characterizing the thermal niche of harmful algae is crucial for understanding and projecting the effects of future climate change on harmful algal blooms. The effects of 6 different temperatures (18-32 °C) on the growth, photophysiology, and toxicity were examined in the dinoflagellate Karlodinium veneficum, and the raphidophytes, Heterosigma akashiwo and Chattonella subsalsa from the Delaware Inland Bays (DIB). K. veneficum and H. akashiwo had skewed unimodal growth patterns, with temperature optima (Topt) at 28.6 and 27.3 °C respectively and an upper thermal niche limit of 32 °C. In contrast, C. subsalsa growth increased linearly with temperature, suggesting Topt and upper thermal boundaries >32 °C. K. veneficum photosystem II (PSII) photochemical efficiency remained stable across all temperatures, while H. akashiwo PSII efficiency declined at higher temperature and C. subsalsa was susceptible to low temperature (~18 °C) photoinactivation. Cell toxicity thermal response was species-specific such that K. veneficum toxicity increased with temperature above Topt. Raphidophyte toxicity peaked at 25-28 °C and was in close agreement with Topt for growth in H. akashiwo but below C. subsalsa maximal growth. The mode of toxicity was markedly different between the dinoflagellate and the raphidophytes such that K. veneficum had greater hemolytic activity while the raphidophytes had pronounced fish gill cell toxicity. These results and patterns of natural abundance for these algae in the DIB suggest that continued ocean warming may contribute to C. subsalsa bloom formation while possibly promoting highly toxic blooms of K. veneficum.
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Affiliation(s)
- Nayani K Vidyarathna
- School of Marine Science and Policy, University of Delaware, Lewes, DE 19958, United States
| | - Erin Papke
- School of Marine Science and Policy, University of Delaware, Lewes, DE 19958, United States
| | - Kathryn J Coyne
- School of Marine Science and Policy, University of Delaware, Lewes, DE 19958, United States
| | - Jonathan H Cohen
- School of Marine Science and Policy, University of Delaware, Lewes, DE 19958, United States
| | - Mark E Warner
- School of Marine Science and Policy, University of Delaware, Lewes, DE 19958, United States.
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29
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Sun C, Xu Y, Hu N, Ma J, Sun S, Cao W, Klobučar G, Hu C, Zhao Y. To evaluate the toxicity of atrazine on the freshwater microalgae Chlorella sp. using sensitive indices indicated by photosynthetic parameters. CHEMOSPHERE 2020; 244:125514. [PMID: 31812061 DOI: 10.1016/j.chemosphere.2019.125514] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 11/26/2019] [Accepted: 11/28/2019] [Indexed: 06/10/2023]
Abstract
Atrazine is a widely-applied herbicide used primarily to control weeds, which can persist in the ecosystem and exert potential toxicity to phytoplankton in the aquatic environment. In this study, acute toxicity of atrazine on microalgae Chlorella sp. was investigated with different initial cell densities (1 × 105 and 1 × 106 cells mL-1) and exposure periods (4 d and 8 d). Both growth rate and photosynthetic parameters of the microalgae in response of atrazine stress were determined to find out the sensitive indices and toxicological mechanisms. Because of the independence of initial cell density as well as the high sensitivity and reliability, the performance index PIABS was verified as the most convincing photosynthetic parameter for indicating IC50 of atrazine on Chlorella sp., being superior to the traditional parameters of growth rate and FV/FM. The IP amplitude (ΔFIP, fluorescence amplitude of the I-to-P-rise in the OJIP curve) was another sensitive biomarker to reflect atrazine stress. Results from chlorophyll fluorescence transient revealed that atrazine damaged the photosystem II (PS II) reaction center, suppressed the electron transport at the donor and receptor sides, and acted on the absorption, transfer, and utilization of light energy. Our results provide confirmatory references for understanding the toxicity and mechanisms of atrazine on freshwater microalgae.
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Affiliation(s)
- Chen Sun
- College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing, 314001, PR China
| | - Yinfeng Xu
- College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing, 314001, PR China
| | - Naitao Hu
- School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, PR China
| | - Jun Ma
- College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing, 314001, PR China
| | - Shiqing Sun
- College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing, 314001, PR China
| | - Weixing Cao
- College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing, 314001, PR China
| | - Göran Klobučar
- Department of Biology, Faculty of Science, University of Zagreb, Croatia
| | - Changwei Hu
- College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing, 314001, PR China.
| | - Yongjun Zhao
- College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing, 314001, PR China.
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30
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Webb JP, van Keulen M, Wong SKS, Hamley E, Nwoba E, Moheimani NR. Light spectral effect on a consortium of filamentous green algae grown on anaerobic digestate piggery effluent (ADPE). ALGAL RES 2020. [DOI: 10.1016/j.algal.2019.101723] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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31
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Carberry L, Roesler C, Drapeau S. Correcting in situ chlorophyll fluorescence time-series observations for nonphotochemical quenching and tidal variability reveals nonconservative phytoplankton variability in coastal waters. LIMNOLOGY AND OCEANOGRAPHY, METHODS 2019; 17:462-473. [PMID: 31598100 PMCID: PMC6774316 DOI: 10.1002/lom3.10325] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 06/02/2019] [Accepted: 06/13/2019] [Indexed: 06/10/2023]
Abstract
Chlorophyll fluorometry is one of the most commonly implemented approaches for estimating phytoplankton biomass in situ, despite documented sources of natural variability and instrumental uncertainty in the relationship between in vivo fluorescence and chlorophyll concentration. A number of strategies are employed to minimize errors and quantify natural variability in this relationship in the open ocean. However, the assumptions underlying these approaches are unsupported in coastal waters due to the short temporal and small spatial scales of variability, as well as the optical complexity. The largest source of variability in the in situ chlorophyll fluorometric signal is nonphotochemical quenching (NPQ). Typically, unquenched nighttime observations are interpolated over the quenched daytime interval, but this assumes a spatial homogeneity not found in tidally impacted coastal waters. Here, we present a model that provides a tidally resolved correction for NPQ in moored chlorophyll fluorescence measurements. The output of the model is a time series of unquenched chlorophyll fluorescence in tidal endmembers (high and low tide extremes), and thus a time series of phytoplankton biomass growth and loss in these endmember populations. Comparison between modeled and measured unquenched time series yields quantification of nonconservative variations in phytoplankton biomass. Tidally modeled interpolation between these endmember time series yields a highly resolved time series of unquenched daytime chlorophyll fluorescence values at the location of the moored sensor. Such data sets provide a critical opportunity for validating the satellite remotely sensed ocean color chlorophyll concentration data product in coastal waters.
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Affiliation(s)
- Luke Carberry
- Earth and Oceanographic Science DepartmentBowdoin CollegeBrunswickMaine
| | - Collin Roesler
- Earth and Oceanographic Science DepartmentBowdoin CollegeBrunswickMaine
| | - Susan Drapeau
- Earth and Oceanographic Science DepartmentBowdoin CollegeBrunswickMaine
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32
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Greenstein KE, Wert EC. Using rapid quantification of adenosine triphosphate (ATP) as an indicator for early detection and treatment of cyanobacterial blooms. WATER RESEARCH 2019; 154:171-179. [PMID: 30797125 DOI: 10.1016/j.watres.2019.02.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 01/10/2019] [Accepted: 02/09/2019] [Indexed: 06/09/2023]
Abstract
Early detection of harmful cyanobacterial blooms allows identification of potential risk and appropriate selection of treatment techniques to prevent exposure in recreational water bodies and drinking water supplies. Here, luminescence-based adenosine triphosphate (ATP) analysis was applied to monitor and treat cultured and naturally occurring cyanobacteria cells. When evaluating lab-cultured Microcystis aeruginosa, ATP concentrations (≤252,000 pg/mL) had improved sensitivity and correlated well (R2 = 0.969) with optical density measurements at 730 nm (OD730; ≤0.297 cm-1). Following one year of monitoring of a surface water supply, ATP concentrations (≤2000 pg/mL) correlated (R2 = 0.791) with chlorophyll-a concentrations (≤50 μg/L). A preliminary early warning threshold of 175 pg ATP/mL corresponded with 5 μg/L chlorophyll-a to initiate increased monitoring (e.g., of cyanotoxins). Following oxidation processes (i.e., chlorine, chloramine, ozone, permanganate), ATP was demonstrated as an indicator of cell lysis and a threshold value of <100 pg/mL was recommended for complete release of intracellular cyanotoxins. ATP was also used to assess efficacy of copper (Cu(II)) treatment on cyanobacteria-laden surface water. While 24-h exposure to 2.5 mg Cu(II)/L did not impact chlorophyll-a, ATP decreased from 13,500 to 128 pg/mL indicating metabolic activity was minimized. Ultimately, ATP analysis holds promise for early detection and mitigation of potentially harmful algal blooms based on superior sensitivity, independence from cell morphology artifacts, rapid time for analysis (<10 min), and ease of deployment in the field compared to conventional methods.
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Affiliation(s)
- Katherine E Greenstein
- Southern Nevada Water Authority (SNWA), P.O. Box 99954, Las Vegas, NV, 89193-9954, United States
| | - Eric C Wert
- Southern Nevada Water Authority (SNWA), P.O. Box 99954, Las Vegas, NV, 89193-9954, United States.
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33
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Brown M, Penta WB, Jones B, Behrenfeld M. The ratio of single-turnover to multiple-turnover fluorescence varies predictably with growth rate and cellular chlorophyll in the green alga Dunaliella tertiolecta. PHOTOSYNTHESIS RESEARCH 2019; 140:65-76. [PMID: 30635858 DOI: 10.1007/s11120-018-00612-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 12/31/2018] [Indexed: 06/09/2023]
Abstract
Marine phytoplankton experience a wide range of nutrient and light conditions in nature and respond to these conditions through changes in growth rate, chlorophyll concentration, and other physiological properties. Chlorophyll fluorescence is a non-invasive and efficient tool for characterizing changes in these physiological properties. In particular, the introduction of fast repetition rate fluorometry (FRRf) into studies of phytoplankton physiology has enabled detailed studies of photosynthetic components and kinetics. One property retrieved with an FRRf is the 'single-turnover' maximum fluorescence (FmST) when the primary electron acceptor, Qa, is reduced but the plastoquinone (PQ) pool is oxidized. A second retrieved property is the 'multiple-turnover' fluorescence (FMT) when both Qa and PQ are reduced. Here, variations in FmST and FMT were measured in the green alga Dunaliella tertiolecta grown under nitrate-limited, light-limited, and replete conditions. The ratio of FmST to FMT (ST/MT) showed a consistent relationship with cellular chlorophyll in D. tertiolecta across all growth conditions. However, the ST/MT ratio decreased with growth rate under nitrate-limited conditions but increased with growth rate under light-limited conditions. In addition, cells from light-limited conditions showed a high accumulation of Qb-nonreducing centers, while cells from nitrate-limited conditions showed little to none. We propose that these findings reflect differences in the reduction and oxidation rates of plastoquinone due to the unique impacts of light and nitrate limitation on the stoichiometry of light-harvesting components and downstream electron acceptors.
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Affiliation(s)
- Matthew Brown
- Department of Botany and Plant Pathology, Oregon State University, 2701 SW Campus Way, Corvallis, OR, 97331, USA.
| | - William Bryce Penta
- Department of Microbiology, Oregon State University, 2820 SW Campus Way, Corvallis, OR, 97331, USA
| | - Bethan Jones
- Department of Botany and Plant Pathology, Oregon State University, 2701 SW Campus Way, Corvallis, OR, 97331, USA
| | - Mike Behrenfeld
- Department of Botany and Plant Pathology, Oregon State University, 2701 SW Campus Way, Corvallis, OR, 97331, USA
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Ekins-Coward T, Boodhoo KVK, Velasquez-Orta S, Caldwell G, Wallace A, Barton R, Flickinger MC. A Microalgae Biocomposite-Integrated Spinning Disk Bioreactor (SDBR): Toward a Scalable Engineering Approach for Bioprocess Intensification in Light-Driven CO 2 Absorption Applications. Ind Eng Chem Res 2019. [DOI: 10.1021/acs.iecr.8b05487] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Thea Ekins-Coward
- Chemical Engineering, School of Engineering, Merz Court, Newcastle University, Newcastle Upon Tyne, NE1 7RU, United Kingdom
| | - Kamelia V. K. Boodhoo
- Chemical Engineering, School of Engineering, Merz Court, Newcastle University, Newcastle Upon Tyne, NE1 7RU, United Kingdom
| | - Sharon Velasquez-Orta
- Chemical Engineering, School of Engineering, Merz Court, Newcastle University, Newcastle Upon Tyne, NE1 7RU, United Kingdom
| | - Gary Caldwell
- Marine Science, School of Natural and Environmental Sciences, Ridley Building, Newcastle University, Newcastle Upon Tyne, United Kingdom, NE1 7RU
| | - Adam Wallace
- Chemical and Biomolecular Engineering, Engineering Building 1, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Ryan Barton
- Chemical and Biomolecular Engineering, Engineering Building 1, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Michael C. Flickinger
- Chemical and Biomolecular Engineering, Engineering Building 1, North Carolina State University, Raleigh, North Carolina 27695, United States
- Golden LEAF Biomanufacturing Training and Education Center, BTEC, North Carolina State University, Raleigh, North Carolina 27695, United States
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35
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Charles ED, Muhamadali H, Goodacre R, Pittman JK. Biochemical signatures of acclimation by Chlamydomonas reinhardtii to different ionic stresses. ALGAL RES 2019. [DOI: 10.1016/j.algal.2018.11.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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36
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Concentrations of Multiple Phytoplankton Pigments in the Global Oceans Obtained from Satellite Ocean Color Measurements with MERIS. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8122678] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The remote sensing of chlorophyll a concentration from ocean color satellites has been an essential variable quantifying phytoplankton in the past decades, yet estimation of accessory pigments from ocean color remote sensing data has remained largely elusive. In this study, we validated the concentrations of multiple pigments (Cpigs) retrieved from in situ and MEdium Resolution Imaging Spectrometer (MERIS) measured remote sensing reflectance (Rrs(λ)) in the global oceans. A multi-pigment inversion model (MuPI) was used to semi-analytically retrieve Cpigs from Rrs(λ). With a set of globally optimized parameters, the accuracy of the retrievals obtained with MuPI is quite promising. Compared with High-Performance Liquid Chromatography (HPLC) measurements near Bermuda, the concentrations of chlorophyll a, b, c ([Chl-a], [Chl-b], [Chl-c]), photoprotective carotenoids ([PPC]), and photosynthetic carotenoids ([PSC]) can be retrieved from MERIS data with a mean unbiased absolute percentage difference of 38%, 78%, 65%, 36%, and 47%, respectively. The advantage of the MuPI approach is the simultaneous retrievals of [Chl-a] and the accessory pigments [Chl-b], [Chl-c], [PPC], [PSC] from MERIS Rrs(λ) based on a closure between the input and output Rrs(λ) spectra. These results can greatly expand scientific studies of ocean biology and biogeochemistry of the global oceans that are not possible when the only available information is [Chl-a].
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37
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Ling Z, Sun D, Wang S, Qiu Z, Huan Y, Mao Z, He Y. Retrievals of phytoplankton community structures from in situ fluorescence measurements by HS-6P. OPTICS EXPRESS 2018; 26:30556-30575. [PMID: 30469953 DOI: 10.1364/oe.26.030556] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 10/19/2018] [Indexed: 06/09/2023]
Abstract
Phytoplankton community is an important organism indicator of monitoring water quality, and accurately estimating its composition and biomass is crucial for understanding marine ecosystems and biogeochemical processes. Identifying phytoplankton species remains a challenging task in the field of oceanography. Phytoplankton fluorescence is an important biological property of phytoplankton, whose fluorescence emissions are closely related to its community. However, the existing estimation approaches for phytoplankton communities by fluorescence are inaccurate and complex. In the present study, a new, simple method was developed for determining the Chlorophytes, Chrysophytes, Cryptophytes, Diatoms, Dinoflagellates, and Prymnesiophytes based on the fluorescence emission spectra measured from the HOBI Labs Hydroscat-6P (HS-6P) in the Bohai Sea, Yellow Sea, and East China Sea. This study used single bands, band ratios, and band combinations of the fluorescence signals to test their correlations with the six dominant algal species. The optimal band forms were confirmed, i.e., X1 (i.e., fl(700), which means the fluorescence emission signal at 700 nm band) for Chlorophytes, Cryptophytes, Dinoflagellates, and Prymnesiophytes (R = 0.947, 0.862, 0.911, and 0.918, respectively) and X7 (i.e., [fl(700) + fl(550)]/[fl(550)/fl(700)], where fl(550) denotes the fluorescence emission signal at 550 nm band) for Chrysophytes and Diatoms (R = 0.893 and 0.963, respectively). These established models here show good performances, yielding low estimation errors (i.e., root mean square errors of 0.16, 0.02, 0.06, 0.36, 0.18, and 0.03 for Chlorophytes, Chrysophytes, Cryptophytes, Diatoms, Dinoflagellates, and Prymnesiophytes, respectively) between in situ and modeled phytoplankton communities. Meanwhile, the spatial distributions of phytoplankton communities observed from both in situ and fluorescence-derived results agreed well. These excellent outputs indicate that the proposed method is to a large extent feasible and robust for estimating those dominant algal species in marine waters. In addition, we have applied this method to three vertical sections, and the retrieved vertical spatial distributions by this method can fill the gap of the common optical remote sensing approach, which usually only detects the sea surface information. Overall, our findings indicate that the proposed method by the fluorescence emission spectra is a potentially promising way to estimate phytoplankton communities, in particular enlarging the profiling information.
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Kerimoglu O, Große F, Kreus M, Lenhart HJ, van Beusekom JEE. A model-based projection of historical state of a coastal ecosystem: Relevance of phytoplankton stoichiometry. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 639:1311-1323. [PMID: 29929297 DOI: 10.1016/j.scitotenv.2018.05.215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 05/17/2018] [Accepted: 05/17/2018] [Indexed: 06/08/2023]
Abstract
We employed a coupled physical-biogeochemical modelling framework for the reconstruction of the historic (H), pre-industrial state of a coastal system, the German Bight (southeastern North Sea), and we investigated its differences with the recent, control (C) state of the system. According to our findings: i) average winter concentrations of dissolved inorganic nitrogen and phosphorus (DIN and DIP) concentrations at the surface are ∼70-90% and ∼50-70% lower in the H state than in the C state within the nearshore waters, and differences gradually diminish towards off-shore waters; ii) differences in average growing season chlorophyll a (Chl) concentrations at the surface between the two states are mostly less than 50%; iii) in the off-shore areas, Chl concentrations in the deeper layers are affected less than in the surface layers; iv) reductions in phytoplankton carbon (C) biomass under the H state are weaker than those in Chl, due to the generally lower Chl:C ratios; v) in some areas the differences in growth rates between the two states are negligible, due to the compensation by lower light limitation under the H state, which in turn explains the lower Chl:C ratios; vi) zooplankton biomass, and hence the grazing pressure on phytoplankton is lower under the H state. This trophic decoupling is caused by the low nutritional quality (i.e., low N:C and P:C) of phytoplankton. These results call for increased attention to the relevance of the acclimation capacity and stoichiometric flexibility of phytoplankton for the prediction of their response to environmental change.
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Affiliation(s)
- Onur Kerimoglu
- Institute for Coastal Research, Helmholtz Zentrum Geesthacht, Geesthacht, Germany.
| | - Fabian Große
- Department of Informatics, University of Hamburg, Hamburg, Germany
| | - Markus Kreus
- Institute of Oceanography, University of Hamburg, Hamburg, Germany
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Feckler A, Rakovic J, Kahlert M, Tröger R, Bundschuh M. Blinded by the light: Increased chlorophyll fluorescence of herbicide-exposed periphyton masks unfavorable structural responses during exposure and recovery. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2018; 203:187-193. [PMID: 30153560 DOI: 10.1016/j.aquatox.2018.08.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 08/17/2018] [Accepted: 08/17/2018] [Indexed: 06/08/2023]
Abstract
In surface waters within agricultural catchments, periphyton - i.e., biofilms containing algae, heterotrophs, and associated detritus - is subjected to multiple stressors including herbicides. Although herbicide effects on periphyton are frequently studied, the focus has been on photosynthesis-inhibiting herbicides while other modes of toxic action have received little attention. Against this background, a 21-days-lasting bioassay was conducted, during which mature periphytic communities were exposed to the carotenoid-biosynthesis-inhibiting herbicide diflufenican for 12 days (up to 10 μg/L; n = 4), followed by a 9-days-lasting recovery phase in herbicide-free medium. Variables related to periphytic functioning (photosynthetic efficiency and non-photochemical quenching) and structure (pigment concentrations, biomass, and algal community structure) were quantified every third day during both experimental phases. Exposure to ≥ 0.2 μg diflufenican/L resulted in 20-25% and 25-30% lowered carotenoid and chlorophyll a concentrations, respectively, likely explained by a reduced algal biovolume as well as diflufenican's mode of toxic action and thus a shift towards a higher heterotrophy of the communities. Despite these adverse effects on the photosynthetic apparatus, the photosynthetic efficiency increased by up to ∼15% under diflufenican exposure judged on higher chlorophyll fluorescence. This may be explained by an up to ∼60% reduced non-photochemical quenching as well as binding of diflufenican to the pigment-protein membrane complex of the photosystem II, two processes causing higher chlorophyll fluorescence. Additionally, phototrophs may have actively increased energy assimilation to cope with higher energy demands under chemical stress. Although periphyton showed some recovery potential following the exposure phase, observed as increasing chlorophyll a concentrations and non-photochemical quenching, periphyton may not be able to quickly recover from stress given the persistent increase in the photosynthetic efficiency. While the processes underlying the observed effects yet remain speculative, the results suggest a shift towards a higher degree of heterotrophy in periphytic communities ultimately increasing the importance of heterotrophic ecosystem functions at impacted sites over the long term.
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Affiliation(s)
- Alexander Feckler
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Box 7050, SE-750 07 Uppsala, Sweden.
| | - Jelena Rakovic
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Box 7050, SE-750 07 Uppsala, Sweden; Department of Soil and Environment, Swedish University of Agricultural Sciences, Box 7014, SE-750 07 Uppsala, Sweden
| | - Maria Kahlert
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Box 7050, SE-750 07 Uppsala, Sweden
| | - Rikard Tröger
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Box 7050, SE-750 07 Uppsala, Sweden
| | - Mirco Bundschuh
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Box 7050, SE-750 07 Uppsala, Sweden; Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, D-76829 Landau, Germany.
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Escoffier N, Bensoussan N, Vilmin L, Flipo N, Rocher V, David A, Métivier F, Groleau A. Estimating ecosystem metabolism from continuous multi-sensor measurements in the Seine River. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:23451-23467. [PMID: 27335018 DOI: 10.1007/s11356-016-7096-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Accepted: 06/13/2016] [Indexed: 06/06/2023]
Abstract
Large rivers are important components of the global C cycle. While they are facing an overall degradation of their water quality, little remains known about the dynamics of their metabolism. In the present study, we used continuous multi-sensors measurements to assess the temporal variability of gross primary production (GPP) and ecosystem respiration (ER) rates of the anthropized Seine River over an annual cycle. Downstream from the Paris urban area, the Seine River is net heterotrophic at the annual scale (-226 gO2 m-2 year-1 or -264 gC m-2 year-1). Yet, it displays a net autotrophy at the daily and seasonal scales during phytoplankton blooms occurring from late winter to early summer. Multivariate analyses were performed to identify the drivers of river metabolism. Daily GPP is best predicted by chlorophyll a (Chla), water temperature (T), light, and rainfalls, and the coupling of daily GPP and Chla allows for the estimation of the productivity rates of the different phytoplankton communities. ER rates are mainly controlled by T and, to a lesser extent, by Chla. The increase of combined sewer overflows related to storm events during the second half of the year stimulates ER and the net heterotrophy of the river. River metabolism is, thus, controlled at different timescales by factors that are affected by human pressures. Continuous monitoring of river metabolism must, therefore, be pursued to deepen our understanding about the responses of ecosystem processes to changing human pressures and climate.
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Affiliation(s)
- N Escoffier
- Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Université Paris Diderot, UMR 7154 CNRS, 75005, Paris, France.
- Nke Instrumentation, Z.I. de Kérandré, rue Gutenberg, 56700, Hennebont, France.
- Stream Biofilm and Ecosystem Research Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 2, CH-1015, Lausanne, Switzerland.
| | - N Bensoussan
- IPSO-FACTO, SCOP arl, Pôle Océanologie et Limnologie, 10, rue Guy Fabre, 13001, Marseille, France
| | - L Vilmin
- Mines ParisTech, PSL Research University, Centre de Géosciences, 35, rue Saint-Honoré, 77305, Fontainebleau, France
- Department of Earth Sciences-Geochemistry, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands
| | - N Flipo
- Mines ParisTech, PSL Research University, Centre de Géosciences, 35, rue Saint-Honoré, 77305, Fontainebleau, France
| | - V Rocher
- Syndicat Interdépartemental pour l'Assainissement de l'Agglomération Parisienne, Direction du Développement et de la Prospective, 82 avenue Kléber, 92700, Colombes, France
| | - A David
- Nke Instrumentation, Z.I. de Kérandré, rue Gutenberg, 56700, Hennebont, France
| | - F Métivier
- Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Université Paris Diderot, UMR 7154 CNRS, 75005, Paris, France
| | - A Groleau
- Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Université Paris Diderot, UMR 7154 CNRS, 75005, Paris, France
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Nutrient limitation suppresses the temperature dependence of phytoplankton metabolic rates. ISME JOURNAL 2018; 12:1836-1845. [PMID: 29695860 PMCID: PMC6018665 DOI: 10.1038/s41396-018-0105-1] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 03/03/2018] [Accepted: 03/12/2018] [Indexed: 11/26/2022]
Abstract
Climate warming has the potential to alter ecosystem function through temperature-dependent changes in individual metabolic rates. The temperature sensitivity of phytoplankton metabolism is especially relevant, since these microorganisms sustain marine food webs and are major drivers of biogeochemical cycling. Phytoplankton metabolic rates increase with temperature when nutrients are abundant, but it is unknown if the same pattern applies under nutrient-limited growth conditions, which prevail over most of the ocean. Here we use continuous cultures of three cosmopolitan and biogeochemically relevant species (Synechococcus sp., Skeletonema costatum and Emiliania huxleyi) to determine the temperature dependence (activation energy, Ea) of metabolism under different degrees of nitrogen (N) limitation. We show that both CO2 fixation and respiration rates increase with N supply but are largely insensitive to temperature. Ea of photosynthesis (0.11 ± 0.06 eV, mean ± SE) and respiration (0.04 ± 0.17 eV) under N-limited growth is significantly smaller than Ea of growth rate under nutrient-replete conditions (0.77 ± 0.06 eV). The reduced temperature dependence of metabolic rates under nutrient limitation can be explained in terms of enzyme kinetics, because both maximum reaction rates and half-saturation constants increase with temperature. Our results suggest that the direct, stimulating effect of rising temperatures upon phytoplankton metabolic rates will be circumscribed to ecosystems with high-nutrient availability.
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Chen H, Zhou W, Chen W, Xie W, Jiang L, Liang Q, Huang M, Wu Z, Wang Q. Simplified, rapid, and inexpensive estimation of water primary productivity based on chlorophyll fluorescence parameter Fo. JOURNAL OF PLANT PHYSIOLOGY 2017; 211:128-135. [PMID: 28187356 DOI: 10.1016/j.jplph.2016.12.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 12/16/2016] [Accepted: 12/21/2016] [Indexed: 06/06/2023]
Abstract
Primary productivity in water environment relies on the photosynthetic production of microalgae. Chlorophyll fluorescence is widely used to detect the growth status and photosynthetic efficiency of microalgae. In this study, a method was established to determine the Chl a content, cell density of microalgae, and water primary productivity by measuring chlorophyll fluorescence parameter Fo. A significant linear relationship between chlorophyll fluorescence parameter Fo and Chl a content of microalgae, as well as between Fo and cell density, was observed under pure-culture conditions. Furthermore, water samples collected from natural aquaculture ponds were used to validate the correlation between Fo and water primary productivity, which is closely related to Chl a content in water. Thus, for a given pure culture of microalgae or phytoplankton (mainly microalgae) in aquaculture ponds or other natural ponds for which the relationship between the Fo value and Chl a content or cell density could be established, Chl a content or cell density could be determined by measuring the Fo value, thereby making it possible to calculate the water primary productivity. It is believed that this method can provide a convenient way of efficiently estimating the primary productivity in natural aquaculture ponds and bringing economic value in limnetic ecology assessment, as well as in algal bloom monitoring.
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Affiliation(s)
- Hui Chen
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, China.
| | - Wei Zhou
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, China; University of Chinese Academy of Sciences, Beijing, China.
| | - Weixian Chen
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, China.
| | - Wei Xie
- TONGWEI COMPANY LIMITED, Chengdu, Sichuang, China.
| | - Liping Jiang
- TONGWEI COMPANY LIMITED, Chengdu, Sichuang, China.
| | | | | | - Zongwen Wu
- TONGWEI COMPANY LIMITED, Chengdu, Sichuang, China.
| | - Qiang Wang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, China.
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Cecchi P, Garrido M, Collos Y, Pasqualini V. Water flux management and phytoplankton communities in a Mediterranean coastal lagoon. Part II: Mixotrophy of dinoflagellates as an adaptive strategy? MARINE POLLUTION BULLETIN 2016; 108:120-133. [PMID: 27126183 DOI: 10.1016/j.marpolbul.2016.04.041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 04/15/2016] [Accepted: 04/17/2016] [Indexed: 06/05/2023]
Abstract
Dinoflagellate proliferation is common in coastal waters, and trophic strategies are often advanced to explain the success of these organisms. The Biguglia lagoon is a Mediterranean brackish ecosystem where eutrophication has long been an issue, and where dominance of dinoflagellates has persisted for several years. Monthly monitoring of fluorescence-based properties of phytoplankton communities carried out in 2010 suggested that photosynthesis alone could not support the observed situation all year round. Contrasting food webs developed depending on the hydrological season, with a gradual shift from autotrophy to heterotrophy. Progressively, microphytoplankton assemblages became unequivocally dominated by a Prorocentrum minimum bloom, which exhibited very weak effective photosynthetic performance, whereas paradoxically its theoretical capacities remained fully operational. Different environmental hypotheses explaining this discrepancy were examined, but rejected. We conclude that P. minimum bloom persistence is sustained by mixotrophic strategies, with complex compromises between phototrophy and phagotrophy, as evidenced by fluorescence-based observations.
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Affiliation(s)
- P Cecchi
- UMR MARBEC, IRD - CNRS - Ifremer - University of Montpellier, CC093, 34095 Montpellier Cedex 5, France.
| | - M Garrido
- UMR 6134 CNRS Sciences for the Environment, UMS 3514 CNRS, Stella Mare, University of Corsica, BP 52, 20250 Corte, France.
| | - Y Collos
- UMR MARBEC, IRD - CNRS - Ifremer - University of Montpellier, CC093, 34095 Montpellier Cedex 5, France
| | - V Pasqualini
- UMR 6134 CNRS Sciences for the Environment, UMS 3514 CNRS, Stella Mare, University of Corsica, BP 52, 20250 Corte, France.
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Hancke K, Dalsgaard T, Sejr MK, Markager S, Glud RN. Phytoplankton Productivity in an Arctic Fjord (West Greenland): Estimating Electron Requirements for Carbon Fixation and Oxygen Production. PLoS One 2015. [PMID: 26218096 PMCID: PMC4517866 DOI: 10.1371/journal.pone.0133275] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Accurate quantification of pelagic primary production is essential for quantifying the marine carbon turnover and the energy supply to the food web. Knowing the electron requirement (Κ) for carbon (C) fixation (ΚC) and oxygen (O2) production (ΚO2), variable fluorescence has the potential to quantify primary production in microalgae, and hereby increasing spatial and temporal resolution of measurements compared to traditional methods. Here we quantify ΚC and ΚO2 through measures of Pulse Amplitude Modulated (PAM) fluorometry, C fixation and O2 production in an Arctic fjord (Godthåbsfjorden, W Greenland). Through short- (2h) and long-term (24h) experiments, rates of electron transfer (ETRPSII), C fixation and/or O2 production were quantified and compared. Absolute rates of ETR were derived by accounting for Photosystem II light absorption and spectral light composition. Two-hour incubations revealed a linear relationship between ETRPSII and gross 14C fixation (R2 = 0.81) during light-limited photosynthesis, giving a ΚC of 7.6 ± 0.6 (mean ± S.E.) mol é (mol C)−1. Diel net rates also demonstrated a linear relationship between ETRPSII and C fixation giving a ΚC of 11.2 ± 1.3 mol é (mol C)−1 (R2 = 0.86). For net O2 production the electron requirement was lower than for net C fixation giving 6.5 ± 0.9 mol é (mol O2)−1 (R2 = 0.94). This, however, still is an electron requirement 1.6 times higher than the theoretical minimum for O2 production [i.e. 4 mol é (mol O2)−1]. The discrepancy is explained by respiratory activity and non-photochemical electron requirements and the variability is discussed. In conclusion, the bio-optical method and derived electron requirement support conversion of ETR to units of C or O2, paving the road for improved spatial and temporal resolution of primary production estimates.
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Affiliation(s)
- Kasper Hancke
- Nordic Center for Earth Evolution (NordCEE), Department of Biology, University of Southern Denmark, Odense, Denmark
- Greenland Climate Research Centre, Greenland Institute of Natural Resources, Nuuk, Greenland
- * E-mail:
| | - Tage Dalsgaard
- Arctic Research Center, Aarhus University, Aarhus, Denmark
| | - Mikael Kristian Sejr
- Greenland Climate Research Centre, Greenland Institute of Natural Resources, Nuuk, Greenland
- Arctic Research Center, Aarhus University, Aarhus, Denmark
| | - Stiig Markager
- Institute for Bioscience, Aarhus University, Aarhus, Denmark
| | - Ronnie Nøhr Glud
- Nordic Center for Earth Evolution (NordCEE), Department of Biology, University of Southern Denmark, Odense, Denmark
- Greenland Climate Research Centre, Greenland Institute of Natural Resources, Nuuk, Greenland
- Arctic Research Center, Aarhus University, Aarhus, Denmark
- Scottish Association for Marine Science, Scottish Marine Institute, Oban, United Kingdom
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Winckelmann D, Bleeke F, Bergmann P, Klöck G. Growth of Cyanobacterium aponinum influenced by increasing salt concentrations and temperature. 3 Biotech 2015; 5:253-260. [PMID: 28324290 PMCID: PMC4434411 DOI: 10.1007/s13205-014-0224-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 04/29/2014] [Indexed: 11/17/2022] Open
Abstract
The increasing requirement of food neutral biofuels demands the detection of alternative sources. The use of non-arable land and waste water streams is widely discussed in this regard. A Cyanobacterium was isolated on the area of a possible algae production side near a water treatment plant in the arid desert region al-Wusta. It was identified as Cyanobacterium aponinum PB1 and is a possible lipid source. To determine its suitability of a production process using this organism, a set of laboratory experiments were performed. Its growth behavior was examined in regard to high temperatures and increasing NaCl concentrations. A productivity of 0.1 g L-1 per day was measured at an alga density below 0.75 g L-1. C. aponinum PB1 showed no sign of altered growth behavior in media containing 70 g L-1 NaCl or less. Detection of a negative effect of NaCl on the growth using Pulse-Amplitude-Modulation chlorophyll fluorescence analysis was not more sensitive than optical density measurement.
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Affiliation(s)
- Dominik Winckelmann
- School of Engineering and Science, Jacobs-University Bremen, Campus Ring 1, 28759, Bremen, Germany
- University of Applied Sciences Bremen, Am Neustadtswall 30, 28199, Bremen, Germany
| | - Franziska Bleeke
- School of Engineering and Science, Jacobs-University Bremen, Campus Ring 1, 28759, Bremen, Germany
- University of Applied Sciences Bremen, Am Neustadtswall 30, 28199, Bremen, Germany
| | - Peter Bergmann
- University of Applied Sciences Bremen, Am Neustadtswall 30, 28199, Bremen, Germany
| | - Gerd Klöck
- University of Applied Sciences Bremen, Am Neustadtswall 30, 28199, Bremen, Germany.
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Li XJ, Li M, Zhou Y, Hu S, Hu R, Chen Y, Li XB. Overexpression of cotton RAV1 gene in Arabidopsis confers transgenic plants high salinity and drought sensitivity. PLoS One 2015; 10:e0118056. [PMID: 25710493 PMCID: PMC4340050 DOI: 10.1371/journal.pone.0118056] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Accepted: 01/03/2015] [Indexed: 11/18/2022] Open
Abstract
RAV (related to ABI3/VP1) protein containing an AP2 domain in the N-terminal region and a B3 domain in the C-terminal region, which belongs to AP2 transcription factor family, is unique in higher plants. In this study, a gene (GhRAV1) encoding a RAV protein of 357 amino acids was identified in cotton (Gossypium hirsutum). Transient expression analysis of the eGFP:GhRAV1 fusion genes in tobacco (Nicotiana tabacum) epidermal cells revealed that GhRAV1 protein was localized in the cell nucleus. Quantitative RT-PCR analysis indicated that expression of GhRAV1 in cotton is induced by abscisic acid (ABA), NaCl and polyethylene glycol (PEG). Overexpression of GhRAV1 in Arabidopsis resulted in plant sensitive to ABA, NaCl and PEG. With abscisic acid (ABA) treatment, seed germination and green seedling rates of the GhRAV1 transgenic plants were remarkably lower than those of wild type. In the presence of NaCl, the seed germination and seedling growth of the GhRAV1 transgenic lines were inhibited greater than those of wild type. And chlorophyll content and maximum photochemical efficiency of the transgenic plants were significantly lower than those of wild type. Under drought stress, the GhRAV1 transgenic plants displayed more severe wilting than wild type. Furthermore, expressions of the stress-related genes were altered in the GhRAV1 transgenic Arabidopsis plants under high salinity and drought stresses. Collectively, our data suggested that GhRAV1 may be involved in response to high salinity and drought stresses through regulating expressions of the stress-related genes during cotton development.
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Affiliation(s)
- Xiao-Jie Li
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Mo Li
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Ying Zhou
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Shan Hu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Rong Hu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Yun Chen
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Xue-Bao Li
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
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Mausz MA, Pohnert G. Phenotypic diversity of diploid and haploid Emiliania huxleyi cells and of cells in different growth phases revealed by comparative metabolomics. JOURNAL OF PLANT PHYSIOLOGY 2015; 172:137-148. [PMID: 25304662 DOI: 10.1016/j.jplph.2014.05.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 05/06/2014] [Accepted: 05/06/2014] [Indexed: 06/04/2023]
Abstract
In phytoplankton a high species diversity of microalgae co-exists at a given time. But diversity is not only reflected by the species composition. Within these species different life phases as well as different metabolic states can cause additional diversity. One important example is the coccolithophore Emiliania huxleyi. Diploid cells play an important role in marine ecosystems since they can form massively abundant algal blooms but in addition the less abundant haploid life phase of E. huxleyi occurs in lower quantities. Both life phases may fulfill different functions in the plankton. We hypothesize that in addition to the functional diversity caused by this life phase transition the growth stage of cells can also influence the metabolic composition and thus the ecological impact of E. huxleyi. Here we introduce a metabolomic survey in dependence of life phases as well as different growth phases to reveal such changes. The comparative metabolomic approach is based on the extraction of intracellular metabolites from intact microalgae, derivatization and analysis by gas chromatography coupled to mass spectrometry (GC-MS). Automated data processing and statistical analysis using canonical analysis of principal coordinates (CAP) revealed unique metabolic profiles for each life phase. Concerning the correlations of metabolites to growth phases, complex patterns were observed. As for example the saccharide mannitol showed its highest concentration in the exponential phase, whereas fatty acids were correlated to stationary and sterols to declining phase. These results are indicative for specific ecological roles of these stages of E. huxleyi and are discussed in the context of previous physiological and ecological studies.
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Affiliation(s)
- Michaela A Mausz
- Department for Bioorganic Analytics, Friedrich Schiller University Jena, Lessingstr. 8, 07743 Jena, Germany; Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Beutenbergstr. 11a, 07745 Jena, Germany
| | - Georg Pohnert
- Department for Bioorganic Analytics, Friedrich Schiller University Jena, Lessingstr. 8, 07743 Jena, Germany.
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Marañón E. Cell size as a key determinant of phytoplankton metabolism and community structure. ANNUAL REVIEW OF MARINE SCIENCE 2015; 7:241-64. [PMID: 25062405 DOI: 10.1146/annurev-marine-010814-015955] [Citation(s) in RCA: 141] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Phytoplankton size structure controls the trophic organization of planktonic communities and their ability to export biogenic materials toward the ocean's interior. Our understanding of the mechanisms that drive the variability in phytoplankton size structure has been shaped by the assumption that the pace of metabolism decreases allometrically with increasing cell size. However, recent field and laboratory evidence indicates that biomass-specific production and growth rates are similar in both small and large cells but peak at intermediate cell sizes. The maximum nutrient uptake rate scales isometrically with cell volume and superisometrically with the minimum nutrient quota. The unimodal size scaling of phytoplankton growth arises from ataxonomic, size-dependent trade-off processes related to nutrient requirement, acquisition, and use. The superior ability of intermediate-size cells to exploit high nutrient concentrations explains their biomass dominance during blooms. Biogeographic patterns in phytoplankton size structure and growth rate are independent of temperature and driven mainly by changes in resource supply.
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Affiliation(s)
- Emilio Marañón
- Departamento de Ecología y Biología Animal, Universidade de Vigo, 36310 Vigo, Spain;
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