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Tariq M, Liu Y, Rizwan A, Shoukat CA, Aftab Q, Lu J, Zhang Y. Impact of elevated CO 2 on soil microbiota: A meta-analytical review of carbon and nitrogen metabolism. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 950:175354. [PMID: 39117202 DOI: 10.1016/j.scitotenv.2024.175354] [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: 05/19/2024] [Revised: 07/17/2024] [Accepted: 08/05/2024] [Indexed: 08/10/2024]
Abstract
In the face of 21st-century challenges driven by population growth and resource depletion, understanding the intricacies of climate change is crucial for environmental sustainability. This review systematically explores the interaction between rising atmospheric CO2 concentrations and soil microbial populations, with possible feedback effects on climate change and terrestrial carbon (C) cycling through a meta-analytical approach. Furthermore, it investigates the enzymatic activities related to carbon acquisition, gene expression patterns governing carbon and nitrogen metabolism, and metagenomic and meta-transcriptomic dynamics in response to elevated CO2 levels. The study reveals that elevated CO2 levels substantially influence soil microbial communities, increasing microbial biomass C and respiration rate by 15 % and upregulating genes involved in carbon and nitrogen metabolism by 12 %. Despite a 14 % increase in C-acquiring enzyme activity, there is a 5 % decrease in N-acquiring enzyme activity, indicating complex microbial responses to CO2 changes. Additionally, fungal marker ratios increase by 14 % compared to bacterial markers, indicating potential ecosystem changes. However, the current inadequacy of data on metagenomic and meta-transcriptomic processes underscores the need for further research. Understanding soil microbial feedback mechanisms is crucial for elucidating the role of rising CO2 levels in carbon sequestration and climate regulation. Consequently, future research should prioritize a comprehensive elucidation of soil microbial carbon cycling, greenhouse gas emission dynamics, and their underlying drivers.
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Affiliation(s)
- Maryam Tariq
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuexian Liu
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Ali Rizwan
- Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad, 38000, Punjab, Pakistan
| | - Chaudhary Ammar Shoukat
- Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qudsia Aftab
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jinfeng Lu
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China; Sino-Danish College, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuanxun Zhang
- Beijing Yanshan Earth Critical Zone National Research Station, University of Chinese Academy of Sciences, Beijing 101408
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2
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He H, Liu Z, Li D, Liu X, Han Y, Sun H, Zhao M, Shao M, Shi L, Hao P, Lai C. Effects of carbon limitation and carbon fertilization on karst lake-reservoir productivity. WATER RESEARCH 2024; 261:122036. [PMID: 38981350 DOI: 10.1016/j.watres.2024.122036] [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: 04/07/2024] [Revised: 06/11/2024] [Accepted: 07/01/2024] [Indexed: 07/11/2024]
Abstract
Nitrogen and phosphorus are universally recognized as limiting elements in the eutrophication processes affecting the majority of the world's lakes, reservoirs, and coastal ecosystems. However, despite extensive research spanning several decades, critical questions in eutrophication science remain unanswered. For example, there is still much to understand about the interactions between carbon limitation and ecosystem stability, and the availability of carbon components adds significant complexity to aquatic resource management. Mounting evidence suggests that aqueous CO2 could be a limiting factor, influencing the structure and succession of aquatic plant communities, especially in karstic lake and reservoir ecosystems. Moreover, the fertilization effect of aqueous CO2 has the potential to enhance carbon sequestration and phosphorus removal. Therefore, it is important to address these uncertainties to achieve multiple positive outcomes, including improved water quality and increased carbon sinks in karst lakes and reservoirs.
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Affiliation(s)
- Haibo He
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences (CAS), Guiyang 550081, China
| | - Zaihua Liu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences (CAS), Guiyang 550081, China; CAS Center for Excellence in Quaternary Science and Global Change, Xi'an 710061, China.
| | - Dongli Li
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Xing Liu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences (CAS), Guiyang 550081, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yongqiang Han
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences (CAS), Guiyang 550081, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hailong Sun
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences (CAS), Guiyang 550081, China
| | - Min Zhao
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences (CAS), Guiyang 550081, China
| | - Mingyu Shao
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences (CAS), Guiyang 550081, China
| | - Liangxing Shi
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences (CAS), Guiyang 550081, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Pengyun Hao
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences (CAS), Guiyang 550081, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chaowei Lai
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences (CAS), Guiyang 550081, China
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Kramer BJ, Turk-Kubo K, Zehr JP, Gobler CJ. Intensification of harmful cyanobacterial blooms in a eutrophic, temperate lake caused by nitrogen, temperature, and CO 2. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 915:169885. [PMID: 38190910 DOI: 10.1016/j.scitotenv.2024.169885] [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: 07/11/2023] [Revised: 01/01/2024] [Accepted: 01/01/2024] [Indexed: 01/10/2024]
Abstract
Warmer temperatures can significantly increase the intensity of cyanobacterial harmful algal blooms (CHABs) in eutrophic freshwater ecosystems. However, few studies have examined the effects of CO2 enrichment in tandem with elevated temperature and/or nutrients on cyanobacterial taxa in freshwater ecosystems. Here, we observed changes in the biomass of cyanobacteria, nutrients, pH, and carbonate chemistry over a two-year period in a shallow, eutrophic freshwater lake and performed experiments to examine the effects and co-effects of CO2, temperature, and nutrient enrichment on cyanobacterial and N2-fixing (diazotrophic) communities assessed via high throughput sequencing of the 16S rRNA and nifH genes, respectively. During both years, there were significant CHABs (50-500 μg cyanobacterial chlorophyll-a L-1) and lake CO2 levels were undersaturated (≤300 μatm pCO2). NH4+ significantly increased the net growth rates of cyanobacteria as well as the biomass of the diazotrophic cyanobacterial order Nostocales under elevated and ambient CO2 conditions. In a fall experiment, the N2 fixation rates of Nostocales were significantly higher when populations were enriched with CO2 and P, relative to CO2-enriched populations that were not amended with P. During a summer experiment, N2 fixation rates increased significantly under N and CO2 - enriched conditions relative to N-enriched and ambient CO2 conditions. Nostocales dominated the diazotrophic communities of both experiments, achieving the highest relative abundance under CO2-enriched conditions when N was added in the first experiment and when CO2 and temperature were elevated in the second experiment, when N2 fixation rates also increased significantly. Collectively, this study indicates that N promotes cyanobacterial blooms including those formed by Dolichospermum and that the biomass and N2 fixation rates of diazotrophic cyanobacterial taxa may benefit from enhanced CO2 levels in eutrophic lakes.
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Affiliation(s)
- Benjamin J Kramer
- School of Marine and Atmospheric Sciences, Stony Brook University, Southampton, NY, United States
| | - Kendra Turk-Kubo
- Oceans Sciences Department, University of California at Santa Cruz, CA, United States
| | - Jonathan P Zehr
- Oceans Sciences Department, University of California at Santa Cruz, CA, United States
| | - Christopher J Gobler
- School of Marine and Atmospheric Sciences, Stony Brook University, Southampton, NY, United States.
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4
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Yan F, Li M, Zang S, Xu Z, Bao M, Wu H. UV radiation and temperature increase alter the PSII function and defense mechanisms in a bloom-forming cyanobacterium Microcystis aeruginosa. Front Microbiol 2024; 15:1351796. [PMID: 38292251 PMCID: PMC10825000 DOI: 10.3389/fmicb.2024.1351796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 01/04/2024] [Indexed: 02/01/2024] Open
Abstract
The aim was to determine the response of a bloom-forming Microcystis aeruginosa to climatic changes. Cultures of M. aeruginosa FACHB 905 were grown at two temperatures (25°C, 30°C) and exposed to high photosynthetically active radiation (PAR: 400-700 nm) alone or combined with UVR (PAR + UVR: 295-700 nm) for specified times. It was found that increased temperature enhanced M. aeruginosa sensitivity to both PAR and PAR + UVR as shown by reduced PSII quantum yields (Fv/Fm) in comparison with that at growth temperature (25°C), the presence of UVR significantly exacerbated the photoinhibition. M. aeruginosa cells grown at high temperature exhibited lower PSII repair rate (Krec) and sustained nonphotochemical quenching (NPQs) induction during the radiation exposure, particularly for PAR + UVR. Although high temperature alone or worked with UVR induced higher SOD and CAT activity and promoted the removal rate of PsbA, it seemed not enough to prevent the damage effect from them showing by the increased value of photoinactivation rate constant (Kpi). In addition, the energetic cost of microcystin synthesis at high temperature probably led to reduced materials and energy available for PsbA turnover, thus may partly account for the lower Krec and the declination of photosynthetic activity in cells following PAR and PAR + UVR exposure. Our findings suggest that increased temperature modulates the sensitivity of M. aeruginosa to UVR by affecting the PSII repair and defense capacity, thus influencing competitiveness and abundance in the future water environment.
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Affiliation(s)
- Fang Yan
- School of Life Science, Ludong University, Yantai, China
- Key Laboratory of Marine Biotechnology in Universities of Shandong, Ludong University, Yantai, China
| | - Mingze Li
- School of Life Science, Ludong University, Yantai, China
- Key Laboratory of Marine Biotechnology in Universities of Shandong, Ludong University, Yantai, China
| | - Shasha Zang
- School of Life Science, Ludong University, Yantai, China
- Key Laboratory of Marine Biotechnology in Universities of Shandong, Ludong University, Yantai, China
| | - Zhiguang Xu
- School of Life Science, Ludong University, Yantai, China
- Key Laboratory of Marine Biotechnology in Universities of Shandong, Ludong University, Yantai, China
| | - Menglin Bao
- School of Life Science, Ludong University, Yantai, China
- Key Laboratory of Marine Biotechnology in Universities of Shandong, Ludong University, Yantai, China
| | - Hongyan Wu
- School of Life Science, Ludong University, Yantai, China
- Key Laboratory of Marine Biotechnology in Universities of Shandong, Ludong University, Yantai, China
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5
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Mao Y, Lin T, Li H, He R, Ye K, Yu W, He Q. Aerobic methane production by phytoplankton as an important methane source of aquatic ecosystems: Reconsidering the global methane budget. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 907:167864. [PMID: 37866611 DOI: 10.1016/j.scitotenv.2023.167864] [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: 08/10/2023] [Revised: 10/09/2023] [Accepted: 10/13/2023] [Indexed: 10/24/2023]
Abstract
Biological methane, a major source of global methane budget, is traditionally thought to be produced in anaerobic environments. However, the recent reports about methane supersaturation occurring in oxygenated water layer, termed as "methane paradox", have challenged this prevailing paradigm. Significantly, growing evidence has indicated that phytoplankton including prokaryotic cyanobacteria and eukaryotic algae are capable of generating methane under aerobic conditions. In this regard, a systematic review of aerobic methane production by phytoplankton is expected to arouse the public attention, contributing to the understanding of methane paradox. Here, we comprehensively summarize the widespread phenomena of methane supersaturation in oxic layers. The remarkable correlation relationships between methane concentration and several key indicators (depth, chlorophyll a level and organic sulfide concentration) indicate the significance of phytoplankton in in-situ methane accumulation. Subsequently, four mechanisms of aerobic methane production by phytoplankton are illustrated in detail, including photosynthesis-driven metabolism, reactive oxygen species (ROS)-driven demethylation of methyl donors, methanogenesis catalyzed by nitrogenase and demethylation of phosphonates catalyzed by CP lyase. The first two pathways occur in various phytoplankton, while the latter two have been specially discovered in cyanobacteria. Additionally, the effects of four crucial factors on aerobic methane production by phytoplankton are also discussed, including phytoplankton species, light, temperature and crucial nutrients. Finally, the measures to control global methane emissions from phytoplankton, the precise intracellular mechanisms of methane production and a more complete global methane budget model are definitely required in the future research on methane production by phytoplankton. This review would provide guidance for future studies of aerobic methane production by phytoplankton and emphasize the potential contribution of aquatic ecosystems to global methane budget.
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Affiliation(s)
- Yufeng Mao
- Key Laboratory of Eco-Environment of Three Gorges Region, Ministry of Education, Chongqing University, Chongqing 400044, China; Key Laboratory of Hydraulic and Waterway Engineering, Ministry of Education, Chongqing Jiaotong University, Chongqing 400074, China; Lingzhi Environmental Protection Co., Ltd, Wuxi 214200, China
| | - Tong Lin
- Key Laboratory of Eco-Environment of Three Gorges Region, Ministry of Education, Chongqing University, Chongqing 400044, China
| | - Hong Li
- Key Laboratory of Eco-Environment of Three Gorges Region, Ministry of Education, Chongqing University, Chongqing 400044, China
| | - Ruixu He
- Key Laboratory of Hydraulic and Waterway Engineering, Ministry of Education, Chongqing Jiaotong University, Chongqing 400074, China
| | - Kailai Ye
- Key Laboratory of Hydraulic and Waterway Engineering, Ministry of Education, Chongqing Jiaotong University, Chongqing 400074, China
| | - Weiwei Yu
- Key Laboratory of Hydraulic and Waterway Engineering, Ministry of Education, Chongqing Jiaotong University, Chongqing 400074, China
| | - Qiang He
- Key Laboratory of Eco-Environment of Three Gorges Region, Ministry of Education, Chongqing University, Chongqing 400044, China.
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6
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Narindri Rara Winayu B, Cheng HF, Hsueh HT, Chu H. Removal of endocrine disruptor compounds, CO 2 fixation, and macromolecules accumulation in Thermosynechococcus sp. CL-1 cultivation. J Biotechnol 2023; 373:1-11. [PMID: 37330059 DOI: 10.1016/j.jbiotec.2023.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 06/07/2023] [Accepted: 06/12/2023] [Indexed: 06/19/2023]
Abstract
Recently, concern on several environmental issues including the pollutant discharge and high concentration of CO2 have gained high interest due to its impact on ecosystem and global warming effect, respectively. Implementation of photosynthetic microorganism carries out numerous advantages including high efficiency of CO2 fixation, the great endurance under extreme conditions and generation of valuable bioproducts. Thermosynechococcus sp. CL-1 (TCL-1), a cyanobacterium, has the ability to perform CO2 fixation and accumulation of various byproducts under extreme conditions like high temperature and alkalinity, presence of estrogen, or even using swine wastewater. This study aimed to assess TCL-1 performance under various endocrine disruptor compounds (bisphenol-A, 17-β-estradiol/E2, and 17-α-ethynilestradiol/EE2), concentrations (0-10 mg/L), light intensities (500-2000 µE/m2/s), and dissolved inorganic carbon/DIC levels (0-113.2 mM). Addition of E2 content even until 10 mg/L carried out insignificant biomass growth interruption along with the improvement in CO2 fixation rate (79.8 ± 0.1 mg/L/h). Besides the influence of E2, application of higher DIC level and light intensity also enhanced the CO2 fixation rate and biomass growth. The highest biodegradation of E2 at 71% was achieved by TCL-1 in the end of 12 h cultivation period. TCL-1 dominantly produced protein (46.7% ± 0.2%), however, production of lipid and carbohydrate (39.5 ± 1.5 and 23.3 ± 0.9%, respectively) also could be considered as the potential source for biofuel production. Thus, this study can provide an efficient strategy in simultaneously dealing with environmental issues with side advantage in production of macromolecules.
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Affiliation(s)
| | - Hsiu Fang Cheng
- Department of Environmental Engineering, National Cheng Kung University, Tainan 701, Taiwan
| | - Hsin-Ta Hsueh
- Sustainable Environment Research Center, National Cheng Kung University, Tainan 701, Taiwan
| | - Hsin Chu
- Department of Environmental Engineering, National Cheng Kung University, Tainan 701, Taiwan.
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7
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Aguiló-Nicolau P, Galmés J, Fais G, Capó-Bauçà S, Cao G, Iñiguez C. Singular adaptations in the carbon assimilation mechanism of the polyextremophile cyanobacterium Chroococcidiopsis thermalis. PHOTOSYNTHESIS RESEARCH 2023; 156:231-245. [PMID: 36941458 PMCID: PMC10154277 DOI: 10.1007/s11120-023-01008-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 02/16/2023] [Indexed: 05/03/2023]
Abstract
Cyanobacteria largely contribute to the biogeochemical carbon cycle fixing ~ 25% of the inorganic carbon on Earth. However, the carbon acquisition and assimilation mechanisms in Cyanobacteria are still underexplored regardless of being of great importance for shedding light on the origins of autotropism on Earth and providing new bioengineering tools for crop yield improvement. Here, we fully characterized these mechanisms from the polyextremophile cyanobacterium Chroococcidiopsis thermalis KOMAREK 1964/111 in comparison with the model cyanobacterial strain, Synechococcus sp. PCC6301. In particular, we analyzed the Rubisco kinetics along with the in vivo photosynthetic CO2 assimilation in response to external dissolved inorganic carbon, the effect of CO2 concentrating mechanism (CCM) inhibitors on net photosynthesis and the anatomical particularities of their carboxysomes when grown under either ambient air (0.04% CO2) or 2.5% CO2-enriched air. Our results show that Rubisco from C. thermalis possess the highest specificity factor and carboxylation efficiency ever reported for Cyanobacteria, which were accompanied by a highly effective CCM, concentrating CO2 around Rubisco more than 140-times the external CO2 levels, when grown under ambient CO2 conditions. Our findings provide new insights into the Rubisco kinetics of Cyanobacteria, suggesting that improved Sc/o values can still be compatible with a fast-catalyzing enzyme. The combination of Rubisco kinetics and CCM effectiveness in C. thermalis relative to other cyanobacterial species might indicate that the co-evolution between Rubisco and CCMs in Cyanobacteria is not as constrained as in other phylogenetic groups.
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Affiliation(s)
- Pere Aguiló-Nicolau
- Research Group on Plant Biology Under Mediterranean Conditions, Universitat de les Illes Balears, INAGEA, Ctra. Valldemossa km. 7.5, 07122, Palma, Balearic Islands, Spain
| | - Jeroni Galmés
- Research Group on Plant Biology Under Mediterranean Conditions, Universitat de les Illes Balears, INAGEA, Ctra. Valldemossa km. 7.5, 07122, Palma, Balearic Islands, Spain.
| | - Giacomo Fais
- Interdepartmental Centre of Environmental Science and Engineering, University of Cagliari, Via San Giorgio 12, 09124, Cagliari, Italy
| | - Sebastià Capó-Bauçà
- Research Group on Plant Biology Under Mediterranean Conditions, Universitat de les Illes Balears, INAGEA, Ctra. Valldemossa km. 7.5, 07122, Palma, Balearic Islands, Spain
| | - Giacomo Cao
- Interdepartmental Centre of Environmental Science and Engineering, University of Cagliari, Via San Giorgio 12, 09124, Cagliari, Italy
- Department of Mechanical, Chemical and Materials Engineering, University of Cagliari, Via Marengo 2, 09123, Cagliari, Italy
| | - Concepción Iñiguez
- Research Group on Plant Biology Under Mediterranean Conditions, Universitat de les Illes Balears, INAGEA, Ctra. Valldemossa km. 7.5, 07122, Palma, Balearic Islands, Spain
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Zhu C, Ji Y, Du X, Kong F, Chi Z, Zhao Y. A smart and precise mixing strategy for efficient and cost-effective microalgae production in open ponds. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 852:158515. [PMID: 36063957 DOI: 10.1016/j.scitotenv.2022.158515] [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: 05/29/2022] [Revised: 08/17/2022] [Accepted: 08/31/2022] [Indexed: 06/15/2023]
Abstract
Microalgae biotechnology is a great candidate for carbon neutralization, wastewater treatment and the sustainable production of biofuels and food. Efficient and cost-effective microalgae production depends on highly coordinating the resources used for algal growth. However, dynamic natural disturbances such as culture temperature and sunlight can lead to the poor coordination and waste of resources. Open ponds are the most commonly used commercial microalgal production systems, and enhanced mixing can significantly increase their productivity, but mixing energy can be seriously wasted due to dynamic disturbances, presenting a hindrance to further reducing production costs. Herein, a smart and precise mixing strategy was developed for open ponds in which a paddle wheel's stirring speed for an open pond was smartly and precisely controlled in real time based on dynamic variations in light intensity and culture temperature. The proposed technology achieved the same biomass productivity of Spirulina platensis (8.37 g m-2 day-1) as a control with a constant high mixing rate under dynamic disturbances while reducing mixing energy inputs by approximately 30 % compared to the control. This study provides a promising method to address serious resource waste and poor coordination due to dynamic natural disturbances, holding great potential for efficient and cost-effective microalgae production.
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Affiliation(s)
- Chenba Zhu
- Carbon Neutral Innovation Research Center, Xiamen University, Xiamen 361005, China; Institute of Marine Microbes and Ecospheres, State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China, 361005.
| | - Yu Ji
- Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074 Aachen, Germany
| | - Xiang Du
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Fantao Kong
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Zhanyou Chi
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China; Ningbo Institute of Dalian University of Technology, No.26 Yucai Road, Jiangbei District, Ningbo 315016, China
| | - Yunpeng Zhao
- State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian 116024, China; Ningbo Institute of Dalian University of Technology, No.26 Yucai Road, Jiangbei District, Ningbo 315016, China.
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Zhang X, Yang X, Huang Y, Hu J, Wu D, Yang N, Wang H. 2-Hydroxychalcone as a Novel Natural Photosynthesis Inhibitor against Bloom-Forming Cyanobacteria. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:15069-15079. [PMID: 36444958 DOI: 10.1021/acs.jafc.2c06665] [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: 06/16/2023]
Abstract
The control of harmful cyanobacterial blooms has been becoming a global challenge. The development of eco-friendly algicides with strong specificity is urgently needed. The photosynthetic apparatus is a promising target site for algicides to minimize the possible harmful effects on animals and humans. In this study, biologically derived 2-hydroxychalcone efficiently inhibited the growth of bloom-forming M. aeruginosa by selectively interfering with photosynthesis. 2-Hydroxychalcone targeting Photosystem II (PSII) inhibited electron transfer between the primary and secondary electron acceptors (QA and QB) and the binding of plastoquinone (PQ) molecules to the QB binding pocket at the acceptor side of PSII, as revealed by polyphasic chlorophyll (Chl) a fluorescence induction and QA- reoxidation kinetics. Molecular docking for 2-hydroxychalcone to D1 protein and the proteomic responses of M. aeruginosa suggested that 2-hydroxychalcone formed a stable monodentate ligand with the nonheme iron in D1 protein, provoking significant modulation of PSII proteins. The unique binding mode of 2-hydroxychalcone with PSII differentiated it from classical PSII inhibitors. Furthermore, 2-hydroxychalcone down-regulated the expression of microcystin (MC) synthesis-related genes to restrain MC synthesis and release. These results indicated the potential application of 2-hydroxychalcone as an algicide or a template scaffold for designing novel derivatives with superior algicidal activity.
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Affiliation(s)
- Xin Zhang
- College of Life Sciences, South-Central Minzu University, Wuhan, Hubei430074, China
| | - Xu Yang
- College of Life Sciences, South-Central Minzu University, Wuhan, Hubei430074, China
| | - Yichen Huang
- College of Life Sciences, South-Central Minzu University, Wuhan, Hubei430074, China
| | - Jinlu Hu
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi710072, China
| | - Diao Wu
- College of Life Sciences, South-Central Minzu University, Wuhan, Hubei430074, China
| | - Niu Yang
- College of Life Sciences, South-Central Minzu University, Wuhan, Hubei430074, China
| | - Haiying Wang
- College of Life Sciences, South-Central Minzu University, Wuhan, Hubei430074, China
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10
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Kramer BJ, Hem R, Gobler CJ. Elevated CO 2 significantly increases N 2 fixation, growth rates, and alters microcystin, anatoxin, and saxitoxin cell quotas in strains of the bloom-forming cyanobacteria, Dolichospermum. HARMFUL ALGAE 2022; 120:102354. [PMID: 36470609 DOI: 10.1016/j.hal.2022.102354] [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: 09/02/2022] [Revised: 11/02/2022] [Accepted: 11/11/2022] [Indexed: 06/17/2023]
Abstract
The effect of rising CO2 levels on cyanobacterial harmful algal blooms (CHABs) is an emerging concern, particularly within eutrophic ecosystems. While elevated pCO2 has been associated with enhanced growth rates of some cyanobacteria, few studies have explored the effect of CO2 and nitrogen availability on diazotrophic (N2-fixing) cyanobacteria that produce cyanotoxins. Here, the effects of elevated CO2 and fixed nitrogen (NO3-) availability on the growth rates, toxin production, and N2 fixation of microcystin, saxitoxin, and anatoxin-a - producing strains of the genus Dolichospermum were quantified. Growth rates of all Dolichospermum spp. were significantly increased by CO2 or both CO2 and NO3- with rates being highest in treatments with the highest levels of CO2 and NO3-for all strains. While NO3- suppressed N2 fixation, diazotrophy significantly increased when NO3--enriched Dolichospermum spp. were supplied with higher CO2 compared to cultures grown under lower CO2 levels. This suggests that diazotrophy will play an increasingly important role in N cycling in CO2-enriched, eutrophic lentic systems. NO3- significantly increased quotas of the N-rich cyanotoxins, microcystin and saxitoxin, at ambient and enriched CO2 levels, respectively. In contrast, elevated CO2 significantly decreased cell quotas of microcystin and saxitoxin, but significantly increased cell quotas of the N-poor cyanotoxin, anatoxin. N2 fixation was significantly negatively and positively correlated with quotas of N-rich and N-poor cyanotoxins, respectively. Findings suggest cellular quotas of N-rich toxins (microcystin and saxitoxin) may be significantly reduced, or cellular quotas of N-poor toxins (anatoxin) may be significantly enhanced, under elevated CO2 conditions during diazotrophic cyanobacterial blooms. Finally, in the future, ecosystems that experience combinations of excessive N loading and CO2 enrichment may become more prone to toxic blooms of Dolichospermum.
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Affiliation(s)
- Benjamin J Kramer
- School of Marine and Atmospheric Sciences, Stony Brook University, 239 Montauk Highway, Southampton, NY, United States, 11968
| | - Ronojoy Hem
- School of Marine and Atmospheric Sciences, Stony Brook University, 239 Montauk Highway, Southampton, NY, United States, 11968
| | - Christopher J Gobler
- School of Marine and Atmospheric Sciences, Stony Brook University, 239 Montauk Highway, Southampton, NY, United States, 11968.
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11
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Cheng Q, Du L, Xu L, Zhao Y, Ma J, Lin H. Toxicity alleviation and metabolism enhancement of nonylphenol in green algae Dictyosphaerium sp. by NaHCO 3. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 848:157698. [PMID: 35908712 DOI: 10.1016/j.scitotenv.2022.157698] [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: 03/28/2022] [Revised: 07/07/2022] [Accepted: 07/25/2022] [Indexed: 06/15/2023]
Abstract
Nonylphenol (NP) toxicity limits the improvements in its algal remediation efficiency. This study comprehensively investigated the performance and mechanism of NaHCO3-driving effects on NP-exposed algae. The results showed that NaHCO3 enhanced algal resistance to NP and the corresponding EC50 values increased 1.31-4.25 times. Further, the toxicological effects of NP reduced with increasing pyrenoid volume and chlorophyll and carotenoids production, and decreasing cellular damage degree. Moreover, the concentration of extracellular polymeric substances was enhanced and more NP adsorption sites were formed. Consistently, RNA-seq demonstrated significant expression alterations in genes related to energy metabolism, cellular synthesis, photosynthesis, and carbon fixation. Besides, NP biodegradation rate was increased by 15.2 % and 11.1 % in the 1, and 4 mg/L NP treatments, respectively. Identification of degradation intermediates and their toxicity via Ecological Structure Activity Relationship program showed that NaHCO3 accelerated sequential α-C removal from NP in algae with faster generation of less toxic metabolites, namely, 4-ethylphenol, 4-cresol and 4-hydroxybenzoic acid. This study provides new insights into the role of NaHCO3 in toxicity alleviation and metabolism enhancement of NP in algae and can assist NP bioremediation efforts in aquatic environment.
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Affiliation(s)
- Qilu Cheng
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, The Institute of Environment, Resource, Soil and Fertilizers, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Linna Du
- Department of Agriculture and Biotechnology, Wenzhou Vocational College of Science and Technology, Wenzhou 325006, China
| | - Ligen Xu
- College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Yuhua Zhao
- College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Junwei Ma
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, The Institute of Environment, Resource, Soil and Fertilizers, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Hui Lin
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, The Institute of Environment, Resource, Soil and Fertilizers, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
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12
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Ma J, Wang P, Hu B, Wang X, Qian J. Synergistic promoting effect of increasing aquatic ammonium and CO 2 on Microcystis aeruginosa. CHEMOSPHERE 2022; 301:134553. [PMID: 35405194 DOI: 10.1016/j.chemosphere.2022.134553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 03/13/2022] [Accepted: 04/05/2022] [Indexed: 06/14/2023]
Abstract
Owing to climate change and intensive agricultural development, freshwater bodies have been affected by increases in both CO2 levels and chemically-reduced forms of N. However, little is known about how these changes affect cyanobacterial growth and blooms. This study explored a range of light conditions (30, 80, 130, or 200 μmol photons/m2/s) wherein Microcystis aeruginosa, a widespread bloom-forming species, was exposed to different concentrations of CO2 (400 parts per million (ppm) and 1000 ppm) in a medium containing NH4+ or NO3-. The interactive effects of N sources and CO2 levels on the C/N metabolic balance and energy balance were examined to assess changes in the growth of M. aeruginosa. When the light intensity was 80 μmol photons/m2/s, elevated CO2 could reduce intracellular reactive oxygen species (ROS) in NH4+-grown M. aeruginosa. Meanwhile, cell density and chlorophyll a (Chl a) increased with increasing CO2 levels, and the increase in Chl a was significantly greater in NH4+-grown M. aeruginosa than in NO3--grown M. aeruginosa. Under light conditions of 200 μmol photons/m2/s, elevated CO2 concentration caused NO3--grown M. aeruginosa to be affected by a large amount of ROS, and the growth of NO3--grown M. aeruginosa was finally suppressed. However, NH4+-grown M. aeruginosa had a smaller amount of ROS and showed improved growth as CO2 was elevated. This difference can be attributed to the faster metabolic pathways in the NH4+ environment, which manifested in a lower accumulation of 2-oxoglutarate and fatty acids as CO2 was elevated. These findings suggest that the simultaneous increase in ammonium and CO2 in aquatic ecosystems confers cyanobacteria with greater advantages than the combination of nitrate and CO2, which may aggravate cyanobacterial blooms.
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Affiliation(s)
- Jingjie Ma
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Peifang Wang
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China.
| | - Bin Hu
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Xun Wang
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Jin Qian
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
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13
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Gao Y, Jia J, Lu Y, Sun K, Wang J, Wang S. Carbon transportation, transformation, and sedimentation processes at the land-river-estuary continuum. FUNDAMENTAL RESEARCH 2022. [DOI: 10.1016/j.fmre.2022.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022] Open
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14
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Chen Y, Wang H, Liao R, Li H, Wang Y, Zhou H, Li J, Huang T, Zhang X, Ma H. Rapidly Measuring Scattered Polarization Parameters of the Individual Suspended Particle with Continuously Large Angular Range. BIOSENSORS 2022; 12:bios12050321. [PMID: 35624622 PMCID: PMC9138884 DOI: 10.3390/bios12050321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Revised: 05/05/2022] [Accepted: 05/09/2022] [Indexed: 11/16/2022]
Abstract
Suspended particles play a vital role in aquatic environments. We propose a method to rapidly measure the scattered polarization parameters of individual suspended particles with continuously large angular range (PCLAR), from 60° to 120° in one shot. A conceptual setup is built to measure PCLAR with 20 kHz; to verify the setup, 10 μm-diameter silica microspheres suspended in water, whose PCLAR are consistent with those simulated by Mie theory, are measured. PCLAR of 6 categories of particles are measured, which enables high-accuracy classification with the help of a convolutional neural network algorithm. PCLAR of different mixtures of Cyclotella stelligera and silica microspheres are measured to successfully identify particulate components. Furthermore, classification ability comparisons of different angular-selection strategies show that PCLAR enables the best classification beyond the single angle, discrete angles and small-ranged angles. Simulated PCLAR of particles with different size, refractive index, and structure show explicit discriminations between them. Inversely, the measured PCLAR are able to estimate the effective size and refractive index of individual Cyclotella cells. Results demonstrate the method’s power, which intrinsically takes the advantage of the optical polarization and the angular coverage. Future prototypes based on this concept would be a promising biosensor for particles in environmental monitoring.
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Affiliation(s)
- Yan Chen
- School of Physics and Optoelectronic Engineering, Yangtze University, Jingzhou 434023, China; (Y.C.); (H.Z.)
- Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; (H.W.); (H.L.); (Y.W.); (J.L.); (T.H.); (H.M.)
| | - Hongjian Wang
- Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; (H.W.); (H.L.); (Y.W.); (J.L.); (T.H.); (H.M.)
| | - Ran Liao
- Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; (H.W.); (H.L.); (Y.W.); (J.L.); (T.H.); (H.M.)
- Correspondence:
| | - Hening Li
- Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; (H.W.); (H.L.); (Y.W.); (J.L.); (T.H.); (H.M.)
| | - Yihao Wang
- Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; (H.W.); (H.L.); (Y.W.); (J.L.); (T.H.); (H.M.)
| | - Hu Zhou
- School of Physics and Optoelectronic Engineering, Yangtze University, Jingzhou 434023, China; (Y.C.); (H.Z.)
- Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; (H.W.); (H.L.); (Y.W.); (J.L.); (T.H.); (H.M.)
| | - Jiajin Li
- Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; (H.W.); (H.L.); (Y.W.); (J.L.); (T.H.); (H.M.)
| | - Tongyu Huang
- Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; (H.W.); (H.L.); (Y.W.); (J.L.); (T.H.); (H.M.)
| | - Xu Zhang
- College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou 434020, China;
| | - Hui Ma
- Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; (H.W.); (H.L.); (Y.W.); (J.L.); (T.H.); (H.M.)
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15
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Sun S, Tang Q, Zhou L, Gao Y, Zhang W, Liu W, Jiang C, Wan J, Zhou L, Xie M. Exploring the photocatalytic inactivation mechanism of Microcystis aeruginosa under visible light using Ag 3PO 4/g-C 3N 4. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:29993-30003. [PMID: 34997489 DOI: 10.1007/s11356-021-17857-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 11/26/2021] [Indexed: 06/14/2023]
Abstract
In this work, a series of Ag3PO4/g-C3N4 (AG) photocatalysts were synthesized. After characterizing the properties, the effects of mass ratio, light intensity, and material dosages on photodegradation were investigated. The material with a 1/2 mass ratio of Ag3PO4/g-C3N4 showed the highest photocatalytic activity under visible light, and the removal efficiency reached 90.22% for an initial suspended algae concentration of 2.7 × 106 cells/mL, 0.1 g of AG, and 3 h of irradiation. These results showed that the conductivity was increased while the total protein and COD contents of the algae suspension were declined rapidly. In contrast, the variations in the malondialdehyde (MDA) level suggested that the algae cell wall was severely damaged and that selective permeability of the membrane was significantly affected. A possible photocatalytic mechanism was proposed and •O2- was shown to be the major reactive oxygen species in the photocatalysis. In summary, during the visible light photocatalytic process, the cell structure was destroyed, which caused the leakage of electrolyte, the inactivation of protein, and the inhibition of photosynthesis; finally, the cells died. This study provides a reference for photodegradation of algae pollution in water bodies.
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Affiliation(s)
- Shiquan Sun
- School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha, 410114, China.
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha, 410114, China.
| | - Qingxin Tang
- School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha, 410114, China
| | - Lean Zhou
- School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha, 410114, China
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha, 410114, China
| | - Yang Gao
- School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha, 410114, China
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha, 410114, China
| | - Wei Zhang
- School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha, 410114, China
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha, 410114, China
| | - Wang Liu
- School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha, 410114, China
| | - Changbo Jiang
- School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha, 410114, China
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha, 410114, China
| | - Junli Wan
- School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha, 410114, China
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha, 410114, China
| | - Lu Zhou
- School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha, 410114, China
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha, 410114, China
| | - Min Xie
- School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha, 410114, China
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha, 410114, China
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16
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Yang Y, Zhang F, Chen X, Li H, Jiao N, Zhang R. Insignificant Response of Bacterioplankton Community to Elevated pCO 2 During a Short-Term Microcosm Experiment in a Subtropical Eutrophic Coastal Ecosystem. Front Microbiol 2021; 12:730377. [PMID: 34867847 PMCID: PMC8633418 DOI: 10.3389/fmicb.2021.730377] [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: 06/24/2021] [Accepted: 10/25/2021] [Indexed: 11/13/2022] Open
Abstract
Ocean acidification, as one of the major consequences of global climate change, markedly affects multiple ecosystem functions in disparate marine environments from coastal habitats to the deep ocean. Evaluation of the responses of marine microbial community to the increasing partial pressure of CO2 (pCO2) is crucial to explore the microbe-driven biogeochemical processes in the future ocean. In this study, a microcosm incubation of eutrophic coastal water from Xiamen Bay under elevated pCO2 (about 1,000 μatm) and control (ambient air, about 380-410 μatm) conditions was conducted to investigate the effect of ocean acidification on the natural bacterioplankton community. During the 5-day incubation period, the chlorophyll a concentration and bacterioplankton abundance were not significantly affected by increased pCO2. Hierarchical clustering and non-metric multidimensional scaling analysis based on Bray-Curtis similarity among the bacterioplankton community derived from the 16S rRNA genes revealed an inconspicuous impact of elevated pCO2 on the bacterial community. During the incubation period, Proteobacteria, Bacteroidetes, Actinobacteria, Cyanobacteria, and Epsilonbacteraeota were predominant in all microcosms. Despite the distinct temporal variation in the composition of the bacterioplankton community during the experimental period, statistical analyses showed that no significant difference was found on bacterioplankton taxa between elevated pCO2 and control, indicating that the bacterioplankton at the population-level were also insensitive to elevated pCO2. Our results therefore suggest that the bacterioplankton communities in the fluctuating and eutrophic coastal ecosystems appear to be adaptable to the short-term elevated pCO2.
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Affiliation(s)
- Yunlan Yang
- College of the Environment and Ecology, Xiamen University, Xiamen, China.,State Key Laboratory of Marine Environmental Science, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen, China
| | - Fei Zhang
- College of the Environment and Ecology, Xiamen University, Xiamen, China.,Laboratory of Marine Biology and Ecology, Ministry of Natural Resources, Third Institute of Oceanography, Xiamen, China
| | - Xiaowei Chen
- State Key Laboratory of Marine Environmental Science, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen, China.,College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Huifang Li
- State Key Laboratory of Marine Environmental Science, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen, China.,College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Nianzhi Jiao
- State Key Laboratory of Marine Environmental Science, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen, China.,College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Rui Zhang
- State Key Laboratory of Marine Environmental Science, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen, China.,College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
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17
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Krachler R, Krachler RF. Northern High-Latitude Organic Soils As a Vital Source of River-Borne Dissolved Iron to the Ocean. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:9672-9690. [PMID: 34251212 DOI: 10.1021/acs.est.1c01439] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Organic soils in the Arctic-boreal region produce small aquatic humic ligands (SAHLs), a category of naturally occurring complexing agents for iron. Every year, large amounts of SAHLs-loaded with iron mobilized in river basins-reach the oceans via river runoff. Recent studies have shown that a fraction of SAHLs belong to the group of strong iron-binding ligands in the ocean. That means, their Fe(III) complexes withstand dissociation even under the conditions of extremely high dilution in the open ocean. Fe(III)-loaded SAHLs are prone to UV-photoinduced ligand-to-metal charge-transfer which leads to disintegration of the complex and, as a consequence, to enhanced concentrations of bioavailable dissolved Fe(II) in sunlit upper water layers. On the other hand, in water depths below the penetration depth of UV, the Fe(III)-loaded SAHLs are fairly resistant to degradation which makes them ideally suited as long-lived molecular transport vehicles for river-derived iron in ocean currents. At locations where SAHLs are present in excess, they can bind to iron originating from various sources. For example, SAHLs were proposed to contribute substantially to the stabilization of hydrothermal iron in deep North Atlantic waters. Recent discoveries have shown that SAHLs, supplied by the Arctic Great Rivers, greatly improve dissolved iron concentrations in the Arctic Ocean and the North Atlantic Ocean. In these regions, SAHLs play a critical role in relieving iron limitation of phytoplankton, thereby supporting the oceanic sink for anthropogenic CO2. The present Critical Review describes the most recent findings and highlights future research directions.
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Affiliation(s)
- Regina Krachler
- Institute of Inorganic Chemistry, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria; http://anorg-chemie.univie.ac.at
| | - Rudolf F Krachler
- Institute of Inorganic Chemistry, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria; http://anorg-chemie.univie.ac.at
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