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Seo HJ, Kim YH, Yang HJ, Park MG, Lee MJ, Kim DJ, Jang SH. Spring protistan communities in response to warming in the northeastern East China Sea. MARINE ENVIRONMENTAL RESEARCH 2024; 196:106376. [PMID: 38316569 DOI: 10.1016/j.marenvres.2024.106376] [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: 08/29/2023] [Revised: 01/05/2024] [Accepted: 01/19/2024] [Indexed: 02/07/2024]
Abstract
The northeastern East China Sea is a highly dynamic marine ecosystem influenced by seasonally varying water mass properties. However, despite being among the world's fastest-warming ocean, there has been limited investigation into the impacts of warming on protistan communities. We collected seawater from two stations (E42 and E46) with different natural protist communities and environmental attributes to investigate the acclimation of the two communities to artificially elevated temperatures (ambient T, +2, and +4 °C). Nutrient and Chl-a conditions reflected oceanographic differences, providing insights into protistan community dynamics. Notably, small-sized autotrophic protists prevailed in the phosphate-deficient E42 community, with mid-incubation heterotrophic conversions. Higher temperatures exacerbated the effects of the P deficiency on the E42 community. While the proportions of Bacillariophyta increased only in the nutrient-balanced E46 communities, those of mixotrophic dinoflagellates increased with elevated temperature, regardless of P deficiency, suggesting that mixotrophy likely aids adaptation in changing marine environments. In summary, the findings of this microcosm study illuminate the potential modulation of spring protistan communities in the northeastern East China Sea under anticipated future warming.
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Affiliation(s)
- Hye Jin Seo
- Department of Oceanography, Chonnam National University, Gwangju 61186, South Korea
| | - Yun Hee Kim
- Department of Oceanography, Chonnam National University, Gwangju 61186, South Korea
| | - Hyun Jun Yang
- Department of Oceanography, Chonnam National University, Gwangju 61186, South Korea
| | - Myung Gil Park
- Department of Oceanography, Chonnam National University, Gwangju 61186, South Korea
| | - Moo Joon Lee
- Department of Marine Biotechnology, Anyang University, Incheon 23038, South Korea
| | - Dae Jin Kim
- Training Ship Administrative Center, Chonnam National University, Yeosu 59626, South Korea
| | - Se Hyeon Jang
- Department of Oceanography, Chonnam National University, Gwangju 61186, South Korea.
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2
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Zhai C, Han L, Xiong C, Ge A, Yue X, Li Y, Zhou Z, Feng J, Ru J, Song J, Jiang L, Yang Y, Zhang L, Wan S. Soil microbial diversity and network complexity drive the ecosystem multifunctionality of temperate grasslands under changing precipitation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167217. [PMID: 37751844 DOI: 10.1016/j.scitotenv.2023.167217] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 08/31/2023] [Accepted: 09/18/2023] [Indexed: 09/28/2023]
Abstract
Soil microbiomes play a critical role in regulating ecosystem multifunctionality. However, whether and how soil protists and microbiome interactions affect ecosystem multifunctionality under climate change is unclear. Here, we transplanted 54 soil monoliths from three typical temperate grasslands (i.e., desert, typical, and meadow steppes) along a precipitation gradient in the Mongolian Plateau and examined their response to nighttime warming, decreased, and increased precipitation. Across the three steppes, nighttime warming only stimulated protistan diversity by 15.61 (absolute change, phylogenetic diversity) but had no effect on ecosystem multifunctionality. Decreased precipitation reduced bacterial (8.78) and fungal (22.28) diversity, but significantly enhanced soil microbiome network complexity by 1.40. Ecosystem multifunctionality was reduced by 0.23 under decreased precipitation, which could be largely attributed to the reduced soil moisture that negatively impacted bacterial and fungal communities. In contrast, increased precipitation had little impact on soil microbial communities. Overall, both bacterial and fungal diversity and network complexity play a fundamental role in maintaining ecosystem multifunctionality in response to drought stress. Protists alter ecosystem multifunctionality by indirectly affecting microbial network complexity. Therefore, not only microbial diversity but also their interactions (regulated by soil protists) should be considered in evaluating the responses of ecosystem multifunctionality, which has important implications for predicting changes in ecosystem functioning under future climate change scenarios.
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Affiliation(s)
- Changchun Zhai
- School of Life Sciences, Institute of Life Science and Green Development, Hebei University, Baoding, Hebei 071002, China; State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Lili Han
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Chao Xiong
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Anhui Ge
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Xiaojing Yue
- School of Life Sciences, Institute of Life Science and Green Development, Hebei University, Baoding, Hebei 071002, China
| | - Ying Li
- School of Life Sciences, Henan University, Kaifeng, Henan 475004, China
| | - Zhenxing Zhou
- School of Life Sciences, Henan University, Kaifeng, Henan 475004, China
| | - Jiayin Feng
- School of Life Sciences, Institute of Life Science and Green Development, Hebei University, Baoding, Hebei 071002, China
| | - Jingyi Ru
- School of Life Sciences, Institute of Life Science and Green Development, Hebei University, Baoding, Hebei 071002, China
| | - Jian Song
- School of Life Sciences, Institute of Life Science and Green Development, Hebei University, Baoding, Hebei 071002, China
| | - Lin Jiang
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Yunfeng Yang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China
| | - Limei Zhang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Shiqiang Wan
- School of Life Sciences, Institute of Life Science and Green Development, Hebei University, Baoding, Hebei 071002, China.
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Liu X, Xie N, Bai M, Li J, Wang G. Composition change and decreased diversity of microbial eukaryotes in the coastal upwelling waters of South China Sea. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 795:148892. [PMID: 34328930 DOI: 10.1016/j.scitotenv.2021.148892] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 07/02/2021] [Accepted: 07/03/2021] [Indexed: 06/13/2023]
Abstract
Upwelling plays an important role in marine ecosystems and potentially reshapes microbial communities by enhanced dispersal and distinct environmental drivers. Relative to that of bacterioplankton, however, the response of eukaryotic microbes to upwelling is largely unknown. Here, we investigated the influence of coastal upwelling in South China Sea on the microbial eukaryotic communities. Unlike several folds of increase in the cell abundance of bacterioplankton in upwelling than non-upwelling stations at corresponding water layers, no significant difference was detected for the total microbial eukaryotic 18S rRNA gene abundance. Moreover, the microbial eukaryotes in the upwelling stations exhibited increasing 18S rRNA gene abundance from the surface to the deep, contrasting the vertical cell abundance pattern of the bacterioplankton; but their vertical abundance patterns were similar in non-upwelling stations. Importantly, the coastal upwelling significantly reduced the community evenness of the microbial eukaryotes and slightly reduced their Shannon diversity. Their community composition also varied obviously especially between the surface waters of upwelling and non-upwelling stations. Among the dominant supergroups, Alveolata was found to be less abundant while Stramenopiles, particularly thraustochytrids and diatoms, to be more abundant in the surface water of upwelling than non-upwelling stations. Temperature was identified as the most important factor of the microbial eukaryotic community composition, suggesting potential effects of the cold upwelling water masses on specific taxa. Overall, our results reveal significant and distinct impacts of coastal upwelling on the abundance, diversity, and community structure of microbial eukaryotes, filling the knowledge gap about the microbial responses to this important marine phenomenon.
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Affiliation(s)
- Xiuping Liu
- Center for Marine Environmental Ecology, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Ningdong Xie
- Center for Marine Environmental Ecology, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Mohan Bai
- Center for Marine Environmental Ecology, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Jiaqian Li
- Center for Marine Environmental Ecology, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Guangyi Wang
- Center for Marine Environmental Ecology, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China; Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin University, Tianjin 300072, China.
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Lalla C, Calvaruso R, Dick S, Reyes-Prieto A. Winogradsky columns as a strategy to study typically rare microbial eukaryotes. Eur J Protistol 2021; 80:125807. [PMID: 34091379 DOI: 10.1016/j.ejop.2021.125807] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 05/05/2021] [Accepted: 05/11/2021] [Indexed: 11/28/2022]
Abstract
Winogradsky columns have been widely used to study soil microbial communities, but the vast majority of those investigations have focused on the ecology and diversity of bacteria. In contrast, microbial eukaryotes (ME) have been regularly overlooked in studies based on experimental soil columns. Despite the recognized ecological relevance of ME in soil communities, investigations focused on ME diversity and the abundance of certain groups of interest are still scarce. In the present study, we used DNA metabarcoding (high-throughput sequencing of the V4 region of the 18S rRNA locus) to survey the ME diversity and abundance in an experimental Winogradsky soil column. Consistent with previous surveys in natural soils, our survey identified members of Cercozoa (Rhizaria; 31.2%), Apicomplexa and Ciliophora (Alveolata; 12.5%) as the predominant ME groups, but at particular depths we also detected the abundant presence of ME lineages that are typically rare in natural environments, such as members of the Vampyrellida (Rhizaria) and Breviatea (Amorphea). Our survey demonstrates that experimental soil columns are an efficient enrichment-culture approach that can enhance investigations about the diversity and ecology of ME in soils.
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Affiliation(s)
- Clarissa Lalla
- Department of Biology, University of New Brunswick, Fredericton. 10 Bailey Drive, Fredericton, New Brunswick E3B 5A3, Canada
| | - Rossella Calvaruso
- Department of Biology, University of New Brunswick, Fredericton. 10 Bailey Drive, Fredericton, New Brunswick E3B 5A3, Canada
| | - Sophia Dick
- Department of Biology, University of New Brunswick, Fredericton. 10 Bailey Drive, Fredericton, New Brunswick E3B 5A3, Canada
| | - Adrian Reyes-Prieto
- Department of Biology, University of New Brunswick, Fredericton. 10 Bailey Drive, Fredericton, New Brunswick E3B 5A3, Canada.
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Significance of Viral Activity for Regulating Heterotrophic Prokaryote Community Dynamics along a Meridional Gradient of Stratification in the Northeast Atlantic Ocean. Viruses 2020; 12:v12111293. [PMID: 33198110 PMCID: PMC7696675 DOI: 10.3390/v12111293] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 11/05/2020] [Accepted: 11/09/2020] [Indexed: 11/17/2022] Open
Abstract
How microbial populations interact influences the availability and flux of organic carbon in the ocean. Understanding how these interactions vary over broad spatial scales is therefore a fundamental aim of microbial oceanography. In this study, we assessed variations in the abundances, production, virus and grazing induced mortality of heterotrophic prokaryotes during summer along a meridional gradient in stratification in the North Atlantic Ocean. Heterotrophic prokaryote abundance and activity varied with phytoplankton biomass, while the relative distribution of prokaryotic subpopulations (ratio of high nucleic acid fluorescent (HNA) and low nucleic acid fluorescent (LNA) cells) was significantly correlated to phytoplankton mortality mode (i.e., viral lysis to grazing rate ratio). Virus-mediate morality was the primary loss process regulating the heterotrophic prokaryotic communities (average 55% of the total mortality), which may be attributed to the strong top-down regulation of the bacterivorous protozoans. Host availability, encounter rate, and HNA:LNA were important factors regulating viral dynamics. Conversely, the abundance and activity of bacterivorous protozoans were largely regulated by temperature and turbulence. The ratio of total microbial mediated mortality to total available prokaryote carbon reveals that over the latitudinal gradient the heterotrophic prokaryote community gradually moved from a near steady state system regulated by high turnover in subtropical region to net heterotrophic production in the temperate region.
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Gu B, Lee C, Ma X, Tan Y, Liu H, Xia X. Effect of Warming on Growth, Grazing, and Community Composition of Free-Living Bacterioplankton in Subtropical Coastal Waters During Winter and Summer. Front Microbiol 2020; 11:534404. [PMID: 33123098 PMCID: PMC7573218 DOI: 10.3389/fmicb.2020.534404] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 09/16/2020] [Indexed: 02/01/2023] Open
Abstract
Global warming is considered a major threat to marine ecosystems, which affects bacterioplankton activity, diversity, and community composition. However, few studies focus on the potential effects of warming on bacterioplankton in subtropical coastal waters in different seasons. Here we investigated the influences of warming on growth, grazing and community composition of bacterioplankton in Hong Kong coastal waters during winter and summer via 1-day incubation experiments. Our results revealed that without grazers, bacterioplankton displayed higher growth rate during summer compared to winter, while warming only significantly increased the growth rate of bacterioplankton in winter. Grazers with size <5 μm were major predators of bacterioplankton. Warming had little effect on grazing in summer but significantly enhanced grazing rates of >5 μm grazers in winter. In both seasons, warming had little influence on bacterial diversity and community composition. Nevertheless, in family and OTU levels, bacterioplankton had different responses to grazing and warming which may result from the selective grazing preference of predators and different temperature optima for bacterioplankton. Furthermore, the presence of >5 μm and <5 μm grazers would result in significant increase of some bacterial families under warming condition. Together, our results suggest that warming have direct impacts on bacterioplankton in subtropical coastal waters during winter and may thus affect global biogeochemical cycles.
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Affiliation(s)
- Bowei Gu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.,University of Chinese Academy of Sciences, Beijing, China.,Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
| | - Candy Lee
- Department of Marine Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Xiao Ma
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.,University of Chinese Academy of Sciences, Beijing, China.,Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
| | - Yehui Tan
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.,University of Chinese Academy of Sciences, Beijing, China.,Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
| | - Hongbin Liu
- Department of Marine Science, The Hong Kong University of Science and Technology, Hong Kong, China.,Hong Kong Branch of Southern Marine Science and Engineering Guangdong Laboratory, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Xiaomin Xia
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.,University of Chinese Academy of Sciences, Beijing, China.,Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
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7
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Protists as catalyzers of microbial litter breakdown and carbon cycling at different temperature regimes. ISME JOURNAL 2020; 15:618-621. [PMID: 33005005 DOI: 10.1038/s41396-020-00792-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 09/14/2020] [Accepted: 09/21/2020] [Indexed: 11/08/2022]
Abstract
Soil bacteria and fungi are key drivers of carbon released from soils to the atmosphere through decomposition of plant-derived organic carbon sources. This process has important consequences for the global climate. While global change factors, such as increased temperature, are known to affect bacterial- and fungal-mediated decomposition rates, the role of trophic interactions in affecting decomposition remains largely unknown. We designed synthetic microbial communities consisting of eight bacterial and eight fungal species and tested the influence of predation by a model protist, Physarum polycephalum, on litter breakdown at 17 and 21 °C. Protists increased CO2 release and litter mass loss by ~35% at 17 °C lower temperatures, while they only had minor effects on microbial-driven CO2 release and mass loss at 21 °C. We found species-specific differences in predator-prey interactions, which may affect microbial community composition and functioning and thus underlie the impact of protists on litter breakdown. Our findings suggest that microbial predation by fast-growing protists is of under-appreciated functional importance, as it affects decomposition and, as such, may influence global carbon dynamics. Our results indicate that we need to better understand the role of trophic interactions within the microbiome in controlling decomposition processes and carbon cycling.
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8
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Changes in the Trophic Pathways within the Microbial Food Web in the Global Warming Scenario: An Experimental Study in the Adriatic Sea. Microorganisms 2020; 8:microorganisms8040510. [PMID: 32260074 PMCID: PMC7232256 DOI: 10.3390/microorganisms8040510] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 03/31/2020] [Accepted: 04/01/2020] [Indexed: 11/21/2022] Open
Abstract
A recent analysis of the Mediterranean Sea surface temperature showed significant annual warming. Since small picoplankton microorganisms play an important role in all major biogeochemical cycles, fluxes and processes occurring in marine systems (the changes at the base of the food web) as a response to human-induced temperature increase, could be amplified through the trophic chains and could also significantly affect different aspects of the structure and functioning of marine ecosystems. In this study, manipulative laboratory growth/grazing experiments were performed under in situ simulated conditions to study the structural and functional changes within the microbial food web after a 3 °C increase in temperature. The results show that a rise in temperature affects the changes in: (1) the growth and grazing rates of picoplankton, (2) their growth efficiency, (3) carrying capacities, (4) sensitivity of their production and grazing mortality to temperature, (5) satisfying protistan grazer carbon demands, (6) their preference in the selection of prey, (7) predator niche breadth and their overlap, (8) apparent uptake rates of nutrients, and (9) carbon biomass flow through the microbial food web. Furthermore, temperature affects the autotrophic and heterotrophic components of picoplankton in different ways.
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Šolic M, Šantic D, Šestanovic S, Bojanic N, Ordulj M, Jozic S, Vrdoljak A. The effect of temperature increase on microbial carbon fluxes in the Adriatic Sea: an experimental approach. FEMS Microbiol Ecol 2019; 94:5078343. [PMID: 30137302 DOI: 10.1093/femsec/fiy169] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 08/22/2018] [Indexed: 11/12/2022] Open
Abstract
An assessment of the temperature increase effect on processes within the microbial food web provides a better insight into the carbon transfer and energy flow processes in marine environments in the global warming perspective. Modified laboratory dilution experiments that allow simultaneous estimates of protozoan grazing and viral lysis on picoplankton groups (bacteria, Prochlorococcus, Synechococcus and pico-eukaryotic algae) under in situ and 3°C above in situ temperatures were performed at seasonal scale. Picoplankton mortality due to grazing was generally higher than that caused by viral lysis, especially in the cold months. The largest part of HNF carbon demand was satisfied by grazing on bacteria throughout the year. Although ciliates satisfied their carbon demand predominantly through grazing on HNF and bacteria, the role of autotrophic picoplankton (APP) as their prey increased significantly in the cold months. Bacteria constituted the most important host for viruses throughout the year. However, during the warm months, APP groups were also significant hosts for viral infection. Under the warming condition the amount of picoplankton biomass transferred to protozoan grazers exceeded the lysed biomass, suggesting that global warming could further increase picoplankton carbon flow toward higher trophic levels in the Adriatic Sea.
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Affiliation(s)
- Mladen Šolic
- Institute of Oceanography and Fisheries, Split, Croatia
| | | | | | | | - Marin Ordulj
- University of Split, Department of Marine Studies, Split, Croatia
| | - Slaven Jozic
- Institute of Oceanography and Fisheries, Split, Croatia
| | - Ana Vrdoljak
- Institute of Oceanography and Fisheries, Split, Croatia
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Šolić M, Šantić D, Šestanović S, Bojanić N, Jozić S, Vrdoljak A, Ordulj M, Kušpilić G. Temperature and phosphorus interacts in controlling the picoplankton carbon flux in the Adriatic Sea: an experimental versus field study. Environ Microbiol 2019; 21:2469-2484. [DOI: 10.1111/1462-2920.14634] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 03/12/2019] [Accepted: 04/16/2019] [Indexed: 11/30/2022]
Affiliation(s)
- Mladen Šolić
- Institute of Oceanography and Fisheries Split Croatia
| | | | | | | | - Slaven Jozić
- Institute of Oceanography and Fisheries Split Croatia
| | - Ana Vrdoljak
- Institute of Oceanography and Fisheries Split Croatia
| | - Marin Ordulj
- Department of Marine StudiesUniversity of Split Split Croatia
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Guo R, Liang Y, Xin Y, Wang L, Mou S, Cao C, Xie R, Zhang C, Tian J, Zhang Y. Insight Into the Pico- and Nano-Phytoplankton Communities in the Deepest Biosphere, the Mariana Trench. Front Microbiol 2018; 9:2289. [PMID: 30319587 PMCID: PMC6168665 DOI: 10.3389/fmicb.2018.02289] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 09/07/2018] [Indexed: 01/21/2023] Open
Abstract
As photoautotrophs, phytoplankton are generally present in the euphotic zone of the ocean, however, recently healthy phytoplankton cells were found to be also ubiquitous in the dark deep sea, i.e., at water depths between 2000 and 4000 m. The distributions of phytoplankton communities in much deeper waters, such as the hadal zone, are unclear. In this study, the vertical distribution of the pico- and nano-phytoplankton (PN) communities from the surface to 8320 m, including the epipelagic, mesopelagic, bathypelagic, and hadal zones, were investigated via both 18S and p23S rRNA gene analysis in the Challenger Deep of the Mariana Trench. The results showed that Dinoflagellata, Chrysophyceae, Haptophyta, Chlorophyta, Prochloraceae, Pseudanabaenaceae, Synechococcaceae, and Eustigmatophyceae, etc., were the predominant PN in the Mariana Trench. Redundancy analyses revealed that depth, followed by temperature, was the most important environmental factors correlated with vertical distribution of PN community. In the hadal zone, the PN community structure was considerably different from those in the shallower zones. Some PN communities, e.g., Eustigmatophyceae and Chrysophyceae, which have the heterotrophic characteristics, were sparse in shallower waters, while they were identified with high relative abundance (94.1% and 20.1%, respectively) at the depth of 8320 m. However, the dinoflagellates and Prochloraceae Prochlorococcus were detected throughout the entire water column. We proposed that vertical sinking, heterotrophic metabolism, and/or the transition to resting stage of phytoplankton might contribute to the presence of phytoplankton in the hadal zone. This study provided insight into the PN community in the Mariana Trench, implied the significance of phytoplankton in exporting organic matters from the euphotic to the hadal zone, and also hinted the possible existence of some undetermined energy metabolism (e.g., heterotrophy) of phytoplankton making themselves adapt and survive in the hadal environment.
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Affiliation(s)
- Ruoyu Guo
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Yantao Liang
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Yu Xin
- Physical Oceanography Laboratory/Qingdao Collaborative Innovation Center of Marine Science and Technology, Key Laboratory of Marine Chemistry Theory & Engineering, Ocean University of China, Qingdao, China
| | - Long Wang
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Shanli Mou
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Chunjie Cao
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Ruize Xie
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Chuanlun Zhang
- Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Jiwei Tian
- Physical Oceanography Laboratory/Qingdao Collaborative Innovation Center of Marine Science and Technology, Key Laboratory of Marine Chemistry Theory & Engineering, Ocean University of China, Qingdao, China
| | - Yongyu Zhang
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
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Tophøj J, Wollenberg RD, Sondergaard TE, Eriksen NT. Feeding and growth of the marine heterotrophic nanoflagellates, Procryptobia sorokini and Paraphysomonas imperforata on a bacterium, Pseudoalteromonas sp. with an inducible defence against grazing. PLoS One 2018; 13:e0195935. [PMID: 29652905 PMCID: PMC5898755 DOI: 10.1371/journal.pone.0195935] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Accepted: 04/03/2018] [Indexed: 11/19/2022] Open
Abstract
Heterotrophic marine nanoflagellates are important grazers on bacteria in the water column. Some marine bacteria appear more resistant to grazing than do others. Marine nanoflagellates can be grown in the laboratory in batch cultures fed specific bacterial isolates. In some cultures, the flagellates appear unable to completely deplete the bacterial prey even when the bacterial strain otherwise is an excellent prey. This may indicate that some marine bacteria are able to induce defence mechanisms if they are grazed by nanoflagellates. Four morphologically distinct marine heterotrophic nanoflagellates, of which 3 were still identified as Procryptobia sorokini (Kinetoplastea) and one as Paraphysomonas imperforata (Chrysophyceae) were isolated from a coastal location along with 3 isolates of the marine bacterium Pseudoalteromonas sp. Flagellate growth and grazing on bacterial prey were analysed in batch cultures. Pseudoalteromonas was a suitable prey for all 4 flagellate isolates. They grazed and grew on Pseudoalteromonas as sole prey with maximal cell-specific growth rates of 0.1–0.25 h-1 and gross growth efficiencies of 38–61%. Exposure to dense flagellate cultures or their supernatants did, however, cause a fraction of the Pseudoalteromonas cells to aggregate and the bacterium became apparently resistant to grazing. Concentrations of suspended Pseudoalteromonas cells were therefore not decreased below 1,700–7,500 cells μL-1 by any of the flagellate isolates. These results indicate that Pseudoalteromonas sp. can be an excellent prey to marine nanoflagellates but also that is in possession of inducible mechanisms that protect against flagellate grazing.
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Affiliation(s)
- Jakob Tophøj
- Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | | | | | - Niels Thomas Eriksen
- Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
- * E-mail:
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Mosier AC, Li Z, Thomas BC, Hettich RL, Pan C, Banfield JF. Elevated temperature alters proteomic responses of individual organisms within a biofilm community. ISME JOURNAL 2014; 9:180-94. [PMID: 25050524 DOI: 10.1038/ismej.2014.113] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 06/01/2014] [Accepted: 06/03/2014] [Indexed: 01/08/2023]
Abstract
Microbial communities that underpin global biogeochemical cycles will likely be influenced by elevated temperature associated with environmental change. Here, we test an approach to measure how elevated temperature impacts the physiology of individual microbial groups in a community context, using a model microbial-based ecosystem. The study is the first application of tandem mass tag (TMT)-based proteomics to a microbial community. We accurately, precisely and reproducibly quantified thousands of proteins in biofilms growing at 40, 43 and 46 °C. Elevated temperature led to upregulation of proteins involved in amino-acid metabolism at the level of individual organisms and the entire community. Proteins from related organisms differed in their relative abundance and functional responses to temperature. Elevated temperature repressed carbon fixation proteins from two Leptospirillum genotypes, whereas carbon fixation proteins were significantly upregulated at higher temperature by a third member of this genus. Leptospirillum group III bacteria may have been subject to viral stress at elevated temperature, which could lead to greater carbon turnover in the microbial food web through the release of viral lysate. Overall, these findings highlight the utility of proteomics-enabled community-based physiology studies, and provide a methodological framework for possible extension to additional mixed culture and environmental sample analyses.
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Affiliation(s)
- Annika C Mosier
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA
| | - Zhou Li
- 1] Oak Ridge National Laboratory, Oak Ridge, TN, USA [2] Graduate School of Genome Science and Technology, University of Tennessee-Oak Ridge National Laboratory, Knoxville, TN, USA
| | - Brian C Thomas
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA
| | | | - Chongle Pan
- Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Jillian F Banfield
- 1] Department of Earth and Planetary Science, University of California, Berkeley, CA, USA [2] Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, CA, USA
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Low temperature constrains growth rates but not short-term ingestion rates of Antarctic ciliates. Polar Biol 2013. [DOI: 10.1007/s00300-013-1291-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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15
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Dolhi JM, Ketchum N, Morgan-Kiss RM. Establishment of microbial eukaryotic enrichment cultures from a chemically stratified antarctic lake and assessment of carbon fixation potential. J Vis Exp 2012:3992. [PMID: 22546995 DOI: 10.3791/3992] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Lake Bonney is one of numerous permanently ice-covered lakes located in the McMurdo Dry Valleys, Antarctica. The perennial ice cover maintains a chemically stratified water column and unlike other inland bodies of water, largely prevents external input of carbon and nutrients from streams. Biota are exposed to numerous environmental stresses, including year-round severe nutrient deficiency, low temperatures, extreme shade, hypersalinity, and 24-hour darkness during the winter (1). These extreme environmental conditions limit the biota in Lake Bonney almost exclusively to microorganisms (2). Single-celled microbial eukaryotes (called "protists") are important players in global biogeochemical cycling (3) and play important ecological roles in the cycling of carbon in the dry valley lakes, occupying both primary and tertiary roles in the aquatic food web. In the dry valley aquatic food web, protists that fix inorganic carbon (autotrophy) are the major producers of organic carbon for organotrophic organisms (4, 2). Phagotrophic or heterotrophic protists capable of ingesting bacteria and smaller protists act as the top predators in the food web (5). Last, an unknown proportion of the protist population is capable of combined mixotrophic metabolism (6, 7). Mixotrophy in protists involves the ability to combine photosynthetic capability with phagotrophic ingestion of prey microorganisms. This form of mixotrophy differs from mixotrophic metabolism in bacterial species, which generally involves uptake dissolved carbon molecules. There are currently very few protist isolates from permanently ice-capped polar lakes, and studies of protist diversity and ecology in this extreme environment have been limited (8, 4, 9, 10, 5). A better understanding of protist metabolic versatility in the simple dry valley lake food web will aid in the development of models for the role of protists in the global carbon cycle. We employed an enrichment culture approach to isolate potentially phototrophic and mixotrophic protists from Lake Bonney. Sampling depths in the water column were chosen based on the location of primary production maxima and protist phylogenetic diversity (4, 11), as well as variability in major abiotic factors affecting protist trophic modes: shallow sampling depths are limited for major nutrients, while deeper sampling depths are limited by light availability. In addition, lake water samples were supplemented with multiple types of growth media to promote the growth of a variety of phototrophic organisms. RubisCO catalyzes the rate limiting step in the Calvin Benson Bassham (CBB) cycle, the major pathway by which autotrophic organisms fix inorganic carbon and provide organic carbon for higher trophic levels in aquatic and terrestrial food webs (12). In this study, we applied a radioisotope assay modified for filtered samples (13) to monitor maximum carboxylase activity as a proxy for carbon fixation potential and metabolic versatility in the Lake Bonney enrichment cultures.
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Terrado R, Medrinal E, Dasilva C, Thaler M, Vincent WF, Lovejoy C. Protist community composition during spring in an Arctic flaw lead polynya. Polar Biol 2011. [DOI: 10.1007/s00300-011-1039-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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17
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Thermal performance curves of Paramecium caudatum: a model selection approach. Eur J Protistol 2011; 47:124-37. [PMID: 21277756 DOI: 10.1016/j.ejop.2010.12.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Revised: 12/14/2010] [Accepted: 12/15/2010] [Indexed: 11/20/2022]
Abstract
The ongoing climate change has motivated numerous studies investigating the temperature response of various organisms, especially that of ectotherms. To correctly describe the thermal performance of these organisms, functions are needed which sufficiently fit to the complete optimum curve. Surprisingly, model-comparisons for the temperature-dependence of population growth rates of an important ectothermic group, the protozoa, are still missing. In this study, temperature reaction norms of natural isolates of the freshwater protist Paramecium caudatum were investigated, considering nearly the entire temperature range. These reaction norms were used to estimate thermal performance curves by applying a set of commonly used model functions. An information theory approach was used to compare models and to identify the best ones for describing these data. Our results indicate that the models which can describe negative growth at the high- and low-temperature branch of an optimum curve are preferable. This is a prerequisite for accurately calculating the critical upper and lower thermal limits. While we detected a temperature optimum of around 29 °C for all investigated clonal strains, the critical thermal limits were considerably different between individual clones. Here, the tropical clone showed the narrowest thermal tolerance, with a shift of its critical thermal limits to higher temperatures.
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