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Martens N, Russnak V, Woodhouse J, Grossart HP, Schaum CE. Metabarcoding reveals potentially mixotrophic flagellates and picophytoplankton as key groups of phytoplankton in the Elbe estuary. ENVIRONMENTAL RESEARCH 2024; 252:119126. [PMID: 38734293 DOI: 10.1016/j.envres.2024.119126] [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: 02/20/2024] [Revised: 05/07/2024] [Accepted: 05/09/2024] [Indexed: 05/13/2024]
Abstract
In estuaries, phytoplankton are faced with strong environmental forcing (e.g. high turbidity, salinity gradients). Taxa that appear under such conditions may play a critical role in maintaining food webs and biological carbon pumping, but knowledge about estuarine biota remains limited. This is also the case in the Elbe estuary where the lower 70 km of the water body are largely unexplored. In the present study, we investigated the phytoplankton composition in the Elbe estuary via metabarcoding. Our aim was to identify key taxa in the unmonitored reaches of this ecosystem and compare our results from the monitored area with available microscopy data. Phytoplankton communities followed distinct seasonal and spatial patterns. Community composition was similar across methods. Contributions of key classes and genera were correlated to each other (p < 0.05) when obtained from reads and biovolume (R2 = 0.59 and 0.33, respectively). Centric diatoms (e.g. Stephanodiscus) were the dominant group - comprising on average 55 % of the reads and 66-69 % of the biovolume. However, results from metabarcoding imply that microscopy underestimates the prevalence of picophytoplankton and flagellates with a potential for mixotrophy (e.g. cryptophytes). This might be due to their small size and sensitivity to fixation agents. We argue that mixotrophic flagellates are ecologically relevant in the mid to lower estuary, where, e.g., high turbidity render living conditions rather unfavorable, and skills such as phagotrophy provide fundamental advantages. Nevertheless, further findings - e.g. important taxa missing from the metabarcoding dataset - emphasize potential limitations of this method and quantitative biases can result from varying numbers of gene copies in different taxa. Further research should address these methodological issues but also shed light on the causal relationship of taxa with the environmental conditions, also with respect to active mixotrophic behavior.
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Affiliation(s)
- Nele Martens
- Institute of Marine Ecosystem and Fishery Science, Olbersweg 24, 22767, Hamburg, Germany.
| | - Vanessa Russnak
- Helmholtz-Zentrum hereon, Max-Planck-Straße 1, 21502, Geesthacht, Germany.
| | - Jason Woodhouse
- Institute of Cell and Systems Biology of Animals, Martin-Luther-King-Platz 3, 20146, Hamburg, Germany.
| | - Hans-Peter Grossart
- Leibniz Institute of Freshwater Ecology and Inland Fisheries, Alte Fischerhütte 2, 16775, Stechlin, Germany; Institute of Biochemistry and Biology, Maulbeerallee 2, 14469, Potsdam, Germany.
| | - C-Elisa Schaum
- Institute of Marine Ecosystem and Fishery Science, Olbersweg 24, 22767, Hamburg, Germany; Center for Earth System Research and Sustainability, Bundesstraße 53-55, 20146, Hamburg, Germany.
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Zhang Y, Nair S, Zhang Z, Zhao J, Zhao H, Lu L, Chang L, Jiao N. Adverse Environmental Perturbations May Threaten Kelp Farming Sustainability by Exacerbating Enterobacterales Diseases. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:5796-5810. [PMID: 38507562 DOI: 10.1021/acs.est.3c09921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
Globally kelp farming is gaining attention to mitigate land-use pressures and achieve carbon neutrality. However, the influence of environmental perturbations on kelp farming remains largely unknown. Recently, a severe disease outbreak caused extensive kelp mortality in Sanggou Bay, China, one of the world's largest high-density kelp farming areas. Here, through in situ investigations and simulation experiments, we find indications that an anomalously dramatic increase in elevated coastal seawater light penetration may have contributed to dysbiosis in the kelp Saccharina japonica's microbiome. This dysbiosis promoted the proliferation of opportunistic pathogenic Enterobacterales, mainly including the genera Colwellia and Pseudoalteromonas. Using transcriptomic analyses, we revealed that high-light conditions likely induced oxidative stress in kelp, potentially facilitating opportunistic bacterial Enterobacterales attack that activates a terrestrial plant-like pattern recognition receptor system in kelp. Furthermore, we uncover crucial genotypic determinants of Enterobacterales dominance and pathogenicity within kelp tissue, including pathogen-associated molecular patterns, potential membrane-damaging toxins, and alginate and mannitol lysis capability. Finally, through analysis of kelp-associated microbiome data sets under the influence of ocean warming and acidification, we conclude that such Enterobacterales favoring microbiome shifts are likely to become more prevalent in future environmental conditions. Our study highlights the need for understanding complex environmental influences on kelp health and associated microbiomes for the sustainable development of seaweed farming.
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Affiliation(s)
- Yongyu Zhang
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No. 189 Songling Road, Qingdao 266101, Shandong, China
- Shandong Energy Institute, No. 189 Songling Road, Qingdao 266101, Shandong, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, Shandong, China
| | - Shailesh Nair
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No. 189 Songling Road, Qingdao 266101, Shandong, China
- Shandong Energy Institute, No. 189 Songling Road, Qingdao 266101, Shandong, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, Shandong, China
| | - Zenghu Zhang
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No. 189 Songling Road, Qingdao 266101, Shandong, China
- Shandong Energy Institute, No. 189 Songling Road, Qingdao 266101, Shandong, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, Shandong, China
| | - Jiulong Zhao
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No. 189 Songling Road, Qingdao 266101, Shandong, China
- Shandong Energy Institute, No. 189 Songling Road, Qingdao 266101, Shandong, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, Shandong, China
| | - Hanshuang Zhao
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No. 189 Songling Road, Qingdao 266101, Shandong, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Longfei Lu
- Weihai Changqing Ocean Science Technology Co., Ltd., Rongcheng 264300, China
| | - Lirong Chang
- Weihai Changqing Ocean Science Technology Co., Ltd., Rongcheng 264300, China
| | - Nianzhi Jiao
- Institute of Marine Microbes and Ecospheres, State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361100, China
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Zhang J, Li X, Wang X, Guan W. Transcriptome analysis of two bloom-forming Prorocentrum species reveals physiological changes related to light and temperature. HARMFUL ALGAE 2023; 125:102421. [PMID: 37220974 DOI: 10.1016/j.hal.2023.102421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 02/25/2023] [Accepted: 03/05/2023] [Indexed: 05/25/2023]
Abstract
Temperature and light substantially influence red tide succession. However, it remains unclear whether the molecular mechanisms differ among species. In this study, we measured the variation in the physiological parameters of growth and pigments and transcriptional levels of two bloom-forming dinoflagellates, namely Prorocentrum micans and P. cordatum. This was undertaken in four treatments that represented two factorial temperature combinations (LT: 20 °C, HT: 28 °C) and light conditions (LL: 50 µmol photons m-2 s-1, HL: 400 µmol photons m-2 s-1) for 7-day batch culture. Growth under high temperature and high light (HTHL) was the fastest, while growth under high temperature and low light (HTLL) was the slowest. The pigments (chlorophyll a and carotenoids) decreased significantly in all high light (HL) treatments, but not in high temperature (HT) treatments. HL alleviated the low light-caused photolimitation and enhanced the growth of both species at low temperatures. However, HT inhibited the growth of both species by inducing oxidative stress under low light conditions. HL mitigated the HT-induced stress on growth in both species by upregulating photosynthesis, antioxidase activity, protein folding, and degradation. The cells of P. micans were more sensitive to HT and HL than those of P. cordatum. This study deepens our understanding of the species-specific mechanism of dinoflagellates at the transcriptomic level, adapting to the future ocean changes including higher solar radiation and higher temperatures in the upper mixed layer.
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Affiliation(s)
- Jiazhu Zhang
- Wenzhou Key Laboratory of Sanitary Microbiology, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Xuanwen Li
- Wenzhou Key Laboratory of Sanitary Microbiology, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Xinjie Wang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian, Liaoning 116024, China
| | - Wanchun Guan
- Wenzhou Key Laboratory of Sanitary Microbiology, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China.
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Ge J, Yang Q, Fang Z, Liu S, Zhu Y, Yao J, Ma Z, Gonçalves RJ, Guan W. Microplastics impacts in seven flagellate microalgae: Role of size and cell wall. ENVIRONMENTAL RESEARCH 2022; 206:112598. [PMID: 34953887 DOI: 10.1016/j.envres.2021.112598] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 12/09/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
The toxicity of microplastic particles (MPs) on aquatic environments has been widely reported; however, their effects on protists are still contradictory. For example, it is unclear if cell size and cell wall have a role in shaping the response of flagellates to MPs. In this study, seven marine flagellated microalgae (six Dinoflagellates and one Raphidophyceae) were incubated with 10 mg L-1 MPs (polystyrene plastic micro-spheres, 1 μm diameter) to address the above question by measuring different response variables, i.e., growth, optimal photochemical efficiency (Fv/Fm), chlorophyll-a (Chl-a) content, superoxide dismutase (SOD) activity, and cell morphology. The effect of MPs on growth and Fv/Fm showed species-specificity effects. Maximum and minimum MPs-induced inhibitions were detected in Karenia mikimotoi (76.43%) and Akashiwo sanguinea (10.16%), respectively, while the rest of the species showed intermediate responses. The presence of MPs was associated with an average reduction of Chl-a content in most cases and with a higher superoxide dismutase activity in all cases. Seven species were classified into two groups by the variation of Chl-a under MPs treatment. One group (Prorocentrum minimum and Karenia mikimotoi) showed increased Chl-a, while the other (P. donghaiense, P. micans, Alexandrium tamarense, Akashiwo sanguinea, Heterosigma akashiwo) showed decreased Chl-a content. The MPs-induced growth inhibition was negatively correlated with cell size in the latter group. SEM images further indicated that MPs-induced malformation in the smaller cells (e.g., P. donghaiense and K. mikimotoi) was more severe than the bigger cells (e.g., A. sanguinea and P. micans), probably due to a relatively higher ratio of the cell surface to cell volume in the former. These results implicate that the effect of MPs on marine flagellated microalgae was related to the cell size among most species but not cell wall. Thus plastic pollution may have size-dependent effects on phytoplankton in future scenarios.
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Affiliation(s)
- Jingke Ge
- School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China; Wenzhou Key Laboratory of Sanitary Microbiology, Key Laboratory of Laboratory Medicine, Ministry of Education, Wenzhou Medical University, China; State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian, 361005, China
| | - Qiongying Yang
- School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China; Wenzhou Key Laboratory of Sanitary Microbiology, Key Laboratory of Laboratory Medicine, Ministry of Education, Wenzhou Medical University, China
| | - Zhouxi Fang
- School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China; Wenzhou Key Laboratory of Sanitary Microbiology, Key Laboratory of Laboratory Medicine, Ministry of Education, Wenzhou Medical University, China
| | - Shuqi Liu
- School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China; Wenzhou Key Laboratory of Sanitary Microbiology, Key Laboratory of Laboratory Medicine, Ministry of Education, Wenzhou Medical University, China
| | - Yue Zhu
- School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China; Wenzhou Key Laboratory of Sanitary Microbiology, Key Laboratory of Laboratory Medicine, Ministry of Education, Wenzhou Medical University, China
| | - Jiang Yao
- School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China; Wenzhou Key Laboratory of Sanitary Microbiology, Key Laboratory of Laboratory Medicine, Ministry of Education, Wenzhou Medical University, China
| | - Zengling Ma
- National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Wenzhou University, Wenzhou, Zhejiang, 325035, China
| | - Rodrigo J Gonçalves
- Laboratorio de Oceanografía Biológica (LOBio), Centro para el Estudio de Sistemas Marinos (CESIMAR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), U9120ACD, Puerto Madryn, Argentina
| | - Wanchun Guan
- School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China; Wenzhou Key Laboratory of Sanitary Microbiology, Key Laboratory of Laboratory Medicine, Ministry of Education, Wenzhou Medical University, China.
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