1
|
Dai W, Wang X, Zhuang M, Sun J, Shen Y, Xia Z, Wu T, Jiang R, Li A, Bi F, Zhang J, He P. Responses of photosynthesis-related genes in Sargassum horneri to high temperature stress. MARINE POLLUTION BULLETIN 2024; 199:115944. [PMID: 38142666 DOI: 10.1016/j.marpolbul.2023.115944] [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: 07/28/2023] [Revised: 12/12/2023] [Accepted: 12/14/2023] [Indexed: 12/26/2023]
Abstract
Golden tide outbreak threatened the marine ecological environment. Sargassum horneri is a single dominant species of the Yellow Sea golden tide, which growth and development are affected by changes in sea water temperature. This study investigated the photosynthetic physiology of copper algae and found that the growth rate, chlorophyll a content, carotenoid content, Fv/Fm, and maximum electron transfer efficiency were significantly reduced, indicating that Sargassum horneri was under stress under high temperature. In this study, high-throughput sequencing was used to analyze the response mechanisms of photosynthesis-related genes in S. horneri under high temperature stress. The results showed that most of the photosynthesis-related genes in S. horneri were downregulated and photosynthesis was inhibited under high temperature stress. However, the expression levels of ferredoxin, ferredoxin-NADP reductase, light-harvesting protein complexes, and oxygen-evolving complex genes were significantly upregulated (P ≤ 0.05) after five days of high temperature treatment. This study found that photosynthesis related genes play a crucial role in regulating the photosynthetic response of S. horneri to high temperature stress.
Collapse
Affiliation(s)
- Wei Dai
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China
| | - Xiaoran Wang
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China
| | - Minmin Zhuang
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China
| | - Jingyi Sun
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China
| | - Yifei Shen
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China
| | - Zhangyi Xia
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China
| | - Tingjian Wu
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China
| | - Ruitong Jiang
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China
| | - Aiqin Li
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China
| | - Fangling Bi
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China
| | - Jianheng Zhang
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China.
| | - Peimin He
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China.
| |
Collapse
|
2
|
Qi L, Cheng P, Wang M, Hu C, Xie Y, Mao K. Where does floating Sargassum in the East China Sea come from? HARMFUL ALGAE 2023; 129:102523. [PMID: 37951622 DOI: 10.1016/j.hal.2023.102523] [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: 06/15/2023] [Revised: 09/25/2023] [Accepted: 10/04/2023] [Indexed: 11/14/2023]
Abstract
Floating macroalgae of Sargassum horneri (S. horneri) in the East China Sea (ECS) has increased in recent years, with ocean warming being one of the driving factors. Yet their possible origins, based on a literature review, are unclear. Here, using multi-sensor high-resolution remote sensing data and numerical experiments for the period of 2015-2023, we show two possible origins of the ECS floating S. horneri, one being local near the Zhejiang coast with initiation in January-February and the other being remote (> 800 km from the first) in the Bohai Sea with initiation in June-November. While their drifting pathways are revealed in the sequential remote sensing imagery, numerical experiments suggest that S. horneri from the remote origin (Bohai Sea) can hardly meander through the strong Yangtze River frontal zone, which may serve as a "wall" to prevent trespassing of surface floating seaweed to the south of the frontal zone, where S. horneri has a local origin. PLAIN LANGUAGE SUMMARY: Sargassum horneri (S. horneri) is a brown macroalgae (seaweed) abundant in surface waters of the East China Sea (ECS), which can serve as a moving habitat, but can also cause major beaching events and environmental problems. Knowledge of its origins is important to help implement mitigation strategies and understand possible ecological impacts along its drifting pathways. Using high-resolution remote sensing images and numerical experiments, we track floating S. horneri in space and time between 2015 and 2023. Two possible origins are identified, one being far away from the ECS and the other being local, both of which are known to have benthic S. horneri. The study also reveals how S. horneri are transported from their source regions resulting in large-scale distributions previously observed in medium-resolution satellite imagery.
Collapse
Affiliation(s)
- Lin Qi
- NOAA Center for Satellite Applications and Research, College Park, MD 20740, USA; Global Science & Technology Inc., Greenbelt, MD 20770, USA.
| | - Peng Cheng
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China
| | - Menghua Wang
- NOAA Center for Satellite Applications and Research, College Park, MD 20740, USA
| | - Chuanmin Hu
- College of Marine Science, University of South Florida, St. Petersburg, FL 33701, USA
| | - Yuyuan Xie
- College of Marine Science, University of South Florida, St. Petersburg, FL 33701, USA
| | - Keyu Mao
- College of Marine Science, University of South Florida, St. Petersburg, FL 33701, USA
| |
Collapse
|
3
|
Song L, Chen Y, Liu S, Xu M, Cui J. SLWE-Net: An improved lightweight U-Net for Sargassum extraction from GOCI images. MARINE POLLUTION BULLETIN 2023; 194:115349. [PMID: 37556975 DOI: 10.1016/j.marpolbul.2023.115349] [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: 05/28/2023] [Revised: 07/14/2023] [Accepted: 07/25/2023] [Indexed: 08/11/2023]
Abstract
The Sargassum bloom has severely impacted the ecological environment of the East China Sea and the Yellow Sea, causing significant economic losses. In recent years, deep learning has seen extensive development due to its outstanding feature extraction capabilities. However, the deep learning process typically involves a large number of parameters and computations. To address this issue, this paper proposes a lightweight deep learning network based on the U-Net framework, called SLWE-NET, which uses lightweight modules to replace the feature extraction modules in U-Net. In this experiment, SLWE-Net performed the best in both extraction accuracy and model lightweight. Compared to the formal U-Net, the number of parameters decreased by 65.83 %, the model size reduced from 94.97 MB to 32.51 MB, and the mIoU increased to 93.81 %. Therefore, the method proposed in this paper is beneficial for Sargassum extraction and provides a basis for operational monitoring.
Collapse
Affiliation(s)
- Lei Song
- College of Oceanography and Space Informatics, China University of Petroleum (East China), Qingdao 266580, China
| | - Yanlong Chen
- College of Oceanography and Space Informatics, China University of Petroleum (East China), Qingdao 266580, China; National Marine Environmental Monitoring Center, No.42 Linghe Street, Dalian, CN 116023, China.
| | - Shanwei Liu
- College of Oceanography and Space Informatics, China University of Petroleum (East China), Qingdao 266580, China.
| | - Mingming Xu
- College of Oceanography and Space Informatics, China University of Petroleum (East China), Qingdao 266580, China
| | - Jianyong Cui
- College of Oceanography and Space Informatics, China University of Petroleum (East China), Qingdao 266580, China
| |
Collapse
|
4
|
Xian R, Yang R, Zhang P, Chen W, Luo Q, Chen J, Chen H. Carotenoid Differences and Genetic Diversity in Populations of Sargassum hemiphyllum and Sargassum fusiforme. Mol Biotechnol 2023; 65:1378-1386. [PMID: 36611100 DOI: 10.1007/s12033-022-00644-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 12/20/2022] [Indexed: 01/09/2023]
Abstract
Sargassum hemiphyllum and Sargassum fusiforme are important benthic seaweeds that grow along the southeastern coast of China. The content of carotenoids in each population was detected by ultra-high performance liquid chromatography (UHPLC). The research results will enrich the theoretical basis and data support concerning the influencing factors of carotenoids in Sargassum. The inter-simple sequence repeat (ISSR) technique was used to study the genetic diversity of four S. hemiphyllum and two S. fusiforme populations, and the results provide a reference for the artificial cultivation of Sargassum. The total carotenoid content of Sargassum ranged from 161.79 ± 4.22 to 269.47 ± 6.15 μg/g. Among the carotenoids, β-carotene and fucoxanthin accounted for 80%, and levels in S. hemiphyllum were generally higher than those in S. fusiforme. The carotenoid contents of S. hemiphyllum from different areas were significantly different (P < 0.05), and the total carotenoids content decreased toward the southern region. The average heterozygosity H ranged from 0.29 to 0.49, and the Shannon diversity index I ranged from 0.44 to 0.69. The polymorphic loci, genetic diversity, and other indicators of S. hemiphyllum populations were higher than those of S. fusiforme, and the diversity of cultivated populations was not significantly lower. The results showed that the genetic variation of Sargassum is limited, and thus, more sexual reproduction can be attempted in breeding. Considering morphological indicators, genetic diversity indexes, and carotenoid content, S. hemiphyllum appears to have a higher commercial development value.
Collapse
Affiliation(s)
- Rui Xian
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Ningbo University, Ningbo, 315211, Zhejiang, China
- Key Laboratory of Marine Biotechnology of Zhejiang Province, Ningbo University, Ningbo, 315211, Zhejiang, China
| | - Rui Yang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Ningbo University, Ningbo, 315211, Zhejiang, China.
- Key Laboratory of Marine Biotechnology of Zhejiang Province, Ningbo University, Ningbo, 315211, Zhejiang, China.
| | - Peng Zhang
- Zhejiang Institute of Marine Aquaculture, Wenzhou, 325005, China
| | - Weizhou Chen
- Guangdong Key Laboratory of Marine Biotechnology, Shantou University, Shantou, 515063, Guangdong, China
| | - Qijun Luo
- Key Laboratory of Marine Biotechnology of Zhejiang Province, Ningbo University, Ningbo, 315211, Zhejiang, China
| | - Juanjuan Chen
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Ningbo University, Ningbo, 315211, Zhejiang, China
- Key Laboratory of Marine Biotechnology of Zhejiang Province, Ningbo University, Ningbo, 315211, Zhejiang, China
| | - Haimin Chen
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Ningbo University, Ningbo, 315211, Zhejiang, China
- Key Laboratory of Marine Biotechnology of Zhejiang Province, Ningbo University, Ningbo, 315211, Zhejiang, China
| |
Collapse
|
5
|
Luo H, Yang Y, Xie S. The ecological effect of large-scale coastal natural and cultivated seaweed litter decay processes: An overview and perspective. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 341:118091. [PMID: 37150170 DOI: 10.1016/j.jenvman.2023.118091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 04/27/2023] [Accepted: 05/02/2023] [Indexed: 05/09/2023]
Abstract
Seaweeds are important components of marine ecosystems and can form a large biomass in a few months. The decomposition of seaweed litter provides energy and material for primary producers and consumers and is an important link between material circulation and energy flow in the ecosystem. However, during the growth process, part of the seaweed is deposited on the sediment surface in the form of litter. Under the joint action of the environment and organisms, elements enriched in seaweed can be released back into the environment in a short time, causing pollution problems. The cultivation yield of seaweed worldwide reached 34.7 million tons in 2019, but the litter produced during the growth and harvest process has become a vital bottleneck that restricts the further improvement of production and sustainable development of the seaweed cultivation industry. Seaweed outbreaks worldwide occur frequently, producing a mass of litter and resulting in environmental pollution on coasts and economic losses, which have negative effects on coastal ecosystems. The objective of this review is to discuss the decomposition process and ecological environmental effects of seaweed litter from the aspects of the research progress on seaweed litter; the impact of seaweed litter on the environment; and its interaction with organisms. Understanding the decomposition process and environmental impact of seaweed litter can provide theoretical support for coastal environmental protection, seaweed resource conservation and sustainable development of the seaweed cultivation industry worldwide. This review suggests that in the process of large-scale seaweed cultivation and seaweed outbreaks, ageing or falling litter should be cleared in a timely manner, mature seaweed should be harvested in stages, and dried seaweed produced after harvest and washed up on shore should be handled properly to ensure the benefits of environmental protection provided by seaweed growth and sustainable seaweed resource development.
Collapse
Affiliation(s)
- Hongtian Luo
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, 570228, China; Institute of Hydrobiology, Key Laboratory of Philosophy and Social Science in Guangdong Province of Jinan University, and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangzhou, 510632, China
| | - Yufeng Yang
- Institute of Hydrobiology, Key Laboratory of Philosophy and Social Science in Guangdong Province of Jinan University, and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangzhou, 510632, China.
| | - Songguang Xie
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, 570228, China.
| |
Collapse
|
6
|
Kim HI, Kim DS, Jung Y, Sung NY, Kim M, Han IJ, Nho EY, Hong JH, Lee JK, Boo M, Kim HL, Baik S, Jung KO, Lee S, Kim CS, Park J. Immune-Enhancing Effect of Sargassum horneri on Cyclophosphamide-Induced Immunosuppression in BALB/c Mice and Primary Cultured Splenocytes. Molecules 2022; 27:8253. [PMID: 36500343 PMCID: PMC9738764 DOI: 10.3390/molecules27238253] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 11/09/2022] [Accepted: 11/22/2022] [Indexed: 11/29/2022] Open
Abstract
Sargassum horneri (SH) is a seaweed that has several features that benefit health. In this study, we investigated the immune-enhancing effect of SH, focusing on the role of spleen-mediated immune functions. Chromatographic analysis of SH identified six types of monosaccharide contents, including mannose, rhamnose glucose, galactose xylose and fucose. SH increased cell proliferation of primary cultured naïve splenocytes treated with or without cyclophosphamide (CPA), an immunosuppression agent. SH also reversed the CPA-induced decrease in Th1 cytokines. In vivo investigation revealed that SH administration can increase the tissue weight of major immune organs, such as the spleen and thymus. A similar effect was observed in CPA-injected immunosuppressed BALB/c mice. SH treatment increased the weight of the spleen and thymus, blood immune cell count and Th1 cytokine expression. Additionally, the YAC-1-targeting activities of natural killer cells, which are important in innate immunity, were upregulated upon SH treatment. Overall, our study demonstrates the immune-enhancing effect of SH, suggesting its potential as a medicinal or therapeutic agent for pathologic conditions involving immunosuppression.
Collapse
Affiliation(s)
- Hyo In Kim
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Dong-Sub Kim
- Division of Natural Product Research, Korea Prime Pharmacy Co., Ltd., Suwon 16229, Republic of Korea
| | - Yunu Jung
- Division of Natural Product Research, Korea Prime Pharmacy Co., Ltd., Suwon 16229, Republic of Korea
| | - Nak-Yun Sung
- Division of Natural Product Research, Korea Prime Pharmacy Co., Ltd., Suwon 16229, Republic of Korea
| | - Minjee Kim
- Division of Natural Product Research, Korea Prime Pharmacy Co., Ltd., Suwon 16229, Republic of Korea
| | - In-Jun Han
- Division of Natural Product Research, Korea Prime Pharmacy Co., Ltd., Suwon 16229, Republic of Korea
| | - Eun Yeong Nho
- Division of Natural Product Research, Korea Prime Pharmacy Co., Ltd., Suwon 16229, Republic of Korea
| | - Joon Ho Hong
- Nano Bio Research Center, Jeonnam Bioindustry Foundation, Jangsung 57248, Republic of Korea
| | - Jin-Kyu Lee
- Department of Food Regulatory Science, Korea University, Sejong 30019, Republic of Korea
| | - Mina Boo
- Department of Science in Korean Medicine, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Hye-Lin Kim
- Department of Pharmacology, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Sangyul Baik
- School of Mechanical Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Kyung Oh Jung
- Department of Anatomy, College of Medicine, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Sanghyun Lee
- Department of Plant Science and Technology, Chung-Ang University, Anseong 17546, Republic of Korea
| | - Chun Sung Kim
- Department of Oral Biochemistry, College of Dentistry, Chosun University, Gwangju 61452, Republic of Korea
| | - Jinbong Park
- Department of Science in Korean Medicine, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea
- Department of Pharmacology, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| |
Collapse
|
7
|
Liu J, Tong Y, Xia J, Sun Y, Zhao X, Sun J, Zhao S, Zhuang M, Zhang J, He P. Ulva macroalgae within local aquaculture ponds along the estuary of Dagu River, Jiaozhou Bay, Qingdao. MARINE POLLUTION BULLETIN 2022; 174:113243. [PMID: 34920239 DOI: 10.1016/j.marpolbul.2021.113243] [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: 07/24/2021] [Revised: 12/03/2021] [Accepted: 12/05/2021] [Indexed: 06/14/2023]
Abstract
Green macroalgal blooms caused by Ulva species have influenced the Shandong Province for 15 consecutive years since 2007, leading to serious damage to the marine environment. Great biomasses of attached Ulva prolifera on Neopyropia aquaculture rafts in the Yellow Sea were considered as sources of blooms. However, it is still unclear whether U. prolifera could survive and settle in the Qingdao coastal environment, Shandong, thus leading to local Ulva blooms in the future. In this research, sampling of Ulva macroalgae in seven Portunus trituberculatus aquaculture ponds along the coast of Qingdao was conducted on August 21, 2019. In total, 24 samples collected from the ponds were analyzed through methods of molecular biological identification (ITS, 5S, and rps2-trnL sequences) and genetic analysis. All the aquaculture ponds contained large amounts of floating Ulva macroalgae, which consisted of three species: U. prolifera, Ulva meridionalis, and Ulva pertusa. Among these species, U. meridionalis, which is usually found in southern Japan, also causes the green tide. In addition, all Ulva macroalgae floated on the surfaces of aquaculture ponds, and were discarded into the local coastal area by aquaculturist. This research raised our awareness of the importance of controlling the spread of the green tide related macroalgae.
Collapse
Affiliation(s)
- Jinlin Liu
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China; North China Sea Environmental Monitoring Center, State Oceanic Administration, Qingdao 266033, China; East China Sea Environmental Monitoring Center, State Oceanic Administration, Shanghai 201206, China.
| | - Yichao Tong
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China
| | - Jing Xia
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China; School of Oceanography, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Yuqing Sun
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China; North China Sea Environmental Monitoring Center, State Oceanic Administration, Qingdao 266033, China
| | - Xiaohui Zhao
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China; State Key Laboratory of Eco-hydraulic in Northwest Arid Region of China, Xi'an University of Technology, Xi'an 710048, China
| | - Jingyi Sun
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China
| | - Shuang Zhao
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China.
| | - Minmin Zhuang
- State Key Lab of Estuarine & Coastal Research, East China Normal University, Shanghai 200062, China
| | - Jianheng Zhang
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China.
| | - Peimin He
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China.
| |
Collapse
|
8
|
Xiao J, Wang Z, Liu D, Fu M, Yuan C, Yan T. Harmful macroalgal blooms (HMBs) in China's coastal water: Green and golden tides. HARMFUL ALGAE 2021; 107:102061. [PMID: 34456020 DOI: 10.1016/j.hal.2021.102061] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 04/23/2021] [Accepted: 05/27/2021] [Indexed: 06/13/2023]
Abstract
Harmful macroalgal blooms (HMBs) have been increasing along China's coasts, causing significant social impacts and economic losses. Besides extensive eutrophication sustaining coastal seaweed tides, the stimuli and dynamics of macroalgal blooms in China are quite complex and require comprehensive studies. This review summarizes the distinct genesis, development and drifting patterns of three HMBs that have persistently occurred in China's coastal waters during recent years: transregional green tides of drifting Ulva prolifera in the Yellow Sea (YS), local green tides of multiple suspended seaweeds in the Bohai Sea and large-scale golden tides of pelagic Sargassum horneri in the YS and East China Sea. While specific containment measures have been developed and implemented to effectively suppress large-scale green tides in the YS, the origin and blooming mechanism of golden tides remain unclear due to lack of field research. With the broad occurrence of HMBs and their increased accumulation on beaches and coastal waters, it is necessary to investigate the blooming mechanism and ecological impacts of these HMBs, especially with the growing stresses of climate change and anthropogenic disturbances.
Collapse
Affiliation(s)
- Jie Xiao
- Key Laboratory of Marine Eco-Environmental Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China; Laboratory of Marine Ecology and Environmental Science, Pilot Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
| | - Zongling Wang
- Key Laboratory of Marine Eco-Environmental Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China; Laboratory of Marine Ecology and Environmental Science, Pilot Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China.
| | - Dongyan Liu
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, 200062, China
| | - Mingzhu Fu
- Key Laboratory of Marine Eco-Environmental Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China; Laboratory of Marine Ecology and Environmental Science, Pilot Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
| | - Chao Yuan
- Key Laboratory of Marine Eco-Environmental Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China
| | - Tian Yan
- Laboratory of Marine Ecology and Environmental Science, Pilot Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; Centre for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China.
| |
Collapse
|
9
|
Raut Y, Capone DG. Macroalgal detrital systems: an overlooked ecological niche for heterotrophic nitrogen fixation. Environ Microbiol 2021; 23:4372-4388. [PMID: 34097341 DOI: 10.1111/1462-2920.15622] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 05/19/2021] [Accepted: 06/01/2021] [Indexed: 11/28/2022]
Abstract
Diazotrophic macroalgal associations (DMAs) can contribute fixed nitrogen (N) to the host macroalgae. Biological nitrogen fixation (BNF) rates investigated using acetylene reduction assays with living macroalgae surrounding Santa Catalina Island were low (maximum: 36 nmol N × g-1 (dw) × h-1 ) and probably insufficient towards helping meet macroalgal N demand. However, DMAs were observed during periods of low nitrate availability in Southern California coastal waters, highlighting the potential importance of diazotrophs during N depleted conditions. Eleven long-term (16-32 days) litter bag decomposition experiments with various macroalgae, especially those with high (> 10) C:N ratios, resulted in much higher BNF rates (maximum: 693 nmol N × g-1 (dw) × h-1 ) than observed with living macroalgae. BNF rates were lower at the beginning of macroalgal decomposition but rapidly increased during the second phase before declining towards the end of decomposition. Labile carbon availability is likely influencing BNF rates throughout macroalgal degradation and limits BNF in the final decomposition stage. Comparable dark and light BNF rates with most macroalgae surveyed suggest macroalgal detrital systems are an overlooked, potentially global, niche for heterotrophic N2 fixation. Lastly, suppressed BNF rates with sodium molybdate additions highlight the prevalence of sulfate reducing diazotrophs.
Collapse
Affiliation(s)
- Yubin Raut
- Marine and Environmental Biology, Department of Biological Sciences, University of Southern California, Los Angeles, California, 90089, USA
| | - Douglas G Capone
- Marine and Environmental Biology, Department of Biological Sciences, University of Southern California, Los Angeles, California, 90089, USA
| |
Collapse
|