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Su D, Wang X, Liu X, Miao J, Zhang Z, Zhang Y, Zhao L, Yu Y, Leng K, Yu Y. A comprehensive study of the colloidal properties, biocompatibility, and synergistic antioxidant actions of Antarctic krill phospholipids. Food Chem 2024; 451:139469. [PMID: 38703727 DOI: 10.1016/j.foodchem.2024.139469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 04/22/2024] [Accepted: 04/22/2024] [Indexed: 05/06/2024]
Abstract
Excipient selection is crucial to address the oxidation and solubility challenges of bioactive substances, impacting their safety and efficacy. AKPL, a novel ω-3 polyunsaturated fatty acids (PUFAs) esterified phospholipid derived from Antarctic krill, demonstrates unique antioxidant capabilities and synergistic effects. It exhibits pronounced surface activity and electronegativity at physiological pH, as evidenced by a critical micelle concentration (CMC) of 0.15 g/L and ζ-potential of -49.9 mV. In aqueous environments, AKPL self-assembles into liposomal structures, offering high biocompatibility and promoting cell proliferation. Its polyunsaturated bond-rich structure provides additional oxidation sites, imparting antioxidant properties superior to other phospholipids like DSPC and DOPC. Additionally, AKPL augments the efficacy of lipophilic antioxidants, such as alpha-tocopherol and curcumin, in aqueous media through both intermolecular and intramolecular interactions. In sum, AKPL emerges as an innovative unsaturated phospholipid, offering new strategies for encapsulating and delivering oxygen-sensitive agents.
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Affiliation(s)
- Dong Su
- State Key Laboratory of Eco-chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China; Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Polar Fisheries, Ministry of Agriculture and Rural Affairs, Qingdao 266071, PR China
| | - Xixi Wang
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Polar Fisheries, Ministry of Agriculture and Rural Affairs, Qingdao 266071, PR China
| | - Xiaofang Liu
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Polar Fisheries, Ministry of Agriculture and Rural Affairs, Qingdao 266071, PR China
| | - Junkui Miao
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Polar Fisheries, Ministry of Agriculture and Rural Affairs, Qingdao 266071, PR China
| | - Zipeng Zhang
- State Key Laboratory of Eco-chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Yating Zhang
- State Key Laboratory of Eco-chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Ling Zhao
- State Key Laboratory of Eco-chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Yuan Yu
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Polar Fisheries, Ministry of Agriculture and Rural Affairs, Qingdao 266071, PR China
| | - Kailiang Leng
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Polar Fisheries, Ministry of Agriculture and Rural Affairs, Qingdao 266071, PR China; Laboratory for Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology (Qingdao), No.1 Wenhai Road, Qingdao 266200, China.
| | - Yueqin Yu
- State Key Laboratory of Eco-chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China.
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2
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Man H, Sun P, Lin J, Ren X, Li D. Based on hydrogen and disulfide-mediated bonds, l-lysine and l-arginine enhanced the gel properties of low-salt mixed shrimp surimi ( Antarctic krill and Pacific white shrimp). Food Chem 2024; 445:138735. [PMID: 38359572 DOI: 10.1016/j.foodchem.2024.138735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 01/29/2024] [Accepted: 02/08/2024] [Indexed: 02/17/2024]
Abstract
This study delved into the effects of l-lysine (Lys) and l-arginine (Arg) on the gel properties and intermolecular interactions of low-salt (NaCl, 1 g/100 g) mixed shrimp surimi (Antarctic krill and Pacific white shrimp). The addition of Lys and Arg improved the gel strength and water holding capacity of low-salt gels, which were superior to the properties of STPP and high-salt (NaCl, 2.25 g/100 g) gels. These results can be attributed to the role of Lys and Arg in enhancing hydrogen and disulfide bonds within the low-salt gel system, promoting the solubilization of myofibrillar proteins (MP) and consequently increasing the number of MP molecules participating in gel formation. Antarctic krill MP did not show gel-forming ability and exerted a diluting effect on low-salt mixed shrimp surimi gels. Molecular docking analysis indicated the stable binding of Lys and Arg to myosin.
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Affiliation(s)
- Hao Man
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, Liaoning, China
| | - Peizi Sun
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, Liaoning, China
| | - Junxin Lin
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, Liaoning, China
| | - Xiang Ren
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, Liaoning, China
| | - Dongmei Li
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, Liaoning, China; Engineering Research Center of Seafood of Ministry of Education of China, Dalian 116034, Liaoning, China; Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian 116034, Liaoning, China; SKL of Marine Food Processing & Safety Control, Dalian Polytechnic University, Dalian 116034, China.
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3
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Groß J, Franco-Santos RM, Virtue P, Nichols PD, Totterdell J, Marcondes MCC, Garrigue C, Botero-Acosta N, Christiansen F, Castrillon J, Caballero SJ, Friedlaender AS, Kawaguchi S, Double MC, Bell EM, Makabe R, Moteki M, Hoem N, Fry B, Burford M, Bengtson Nash S. No distinct local cuisines among humpback whales: A population diet comparison in the Southern Hemisphere. Sci Total Environ 2024; 931:172939. [PMID: 38701928 DOI: 10.1016/j.scitotenv.2024.172939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 04/24/2024] [Accepted: 04/30/2024] [Indexed: 05/05/2024]
Abstract
Southern hemisphere humpback whale (Megaptera novaeangliae, SHHW) breeding populations follow a high-fidelity Antarctic krill (Euphausia superba) diet while feeding in distinct sectors of the Southern Ocean. Their capital breeding life history requires predictable ecosystem productivity to fuel migration and migration-related behaviours. It is therefore postulated that populations feeding in areas subject to the strongest climate change impacts are more likely to show the first signs of a departure from a high-fidelity krill diet. We tested this hypothesis by investigating blubber fatty acid profiles and skin stable isotopes obtained from five SHHW populations in 2019, and comparing them to Antarctic krill stable isotopes sampled in three SHHW feeding areas in the Southern Ocean in 2019. Fatty acid profiles and δ13C and δ15N varied significantly among all five populations, however, calculated trophic positions did not (2.7 to 3.1). Similarly, fatty acid ratios, 16:1ω7c/16:0 and 20:5ω3/22:6ω3 were above 1, showing that whales from all five populations are secondary heterotrophs following an omnivorous diet with a diatom-origin. Thus, evidence for a potential departure from a high-fidelity Antarctic krill diet was not seen in any population. δ13C of all populations were similar to δ13C of krill sampled in productive upwelling areas or the marginal sea-ice zone. Consistency in trophic position and diet origin but significant fatty acid and stable isotope differences demonstrate that the observed variability arises at lower trophic levels. Our results indicate that, at present, there is no evidence of a divergence from a high-fidelity krill diet. Nevertheless, the characteristic isotopic signal of whales feeding in productive upwelling areas, or in the marginal sea-ice zone, implies that future cryosphere reductions could impact their feeding ecology.
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Affiliation(s)
- Jasmin Groß
- Centre for Planetary Health and Food Security, Southern Ocean Persistent Organic Pollutants Program, Griffith University, 4111 Nathan, QLD, Australia; Alfred-Wegener-Institute Helmholtz-Centre for Polar and Marine Research, Bremerhaven, Germany; Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg (HIFMB), Ammerländer Heerstrasse 231, 26129 Oldenburg, Germany.
| | - Rita M Franco-Santos
- Institute for Marine and Antarctic Studies, University of Tasmania, 7004 Hobart, TAS, Australia
| | - Patti Virtue
- Institute for Marine and Antarctic Studies, University of Tasmania, 7004 Hobart, TAS, Australia; CSIRO Environment, 7004 Hobart, TAS, Australia
| | - Peter D Nichols
- Institute for Marine and Antarctic Studies, University of Tasmania, 7004 Hobart, TAS, Australia; CSIRO Environment, 7004 Hobart, TAS, Australia
| | | | | | - Claire Garrigue
- UMR 250/9220 ENTROPIE, IRD, Université de La Réunion, Université de la Nouvelle-Calédonie, CNRS, Ifremer, Laboratoired'Excellence-CORAIL, BPA5 Nouméa, New Caledonia; Opération Cétacés, Nouméa, New Caledonia
| | | | - Fredrik Christiansen
- Zoophysiology, Department of Biology, Aarhus University, Aarhus, Denmark; Aarhus Institute of Advanced Studies, Aarhus C, Denmark
| | - Juliana Castrillon
- Centre for Planetary Health and Food Security, Southern Ocean Persistent Organic Pollutants Program, Griffith University, 4111 Nathan, QLD, Australia
| | - Susana J Caballero
- Laboratorio de Ecología Molecular de Vertebrados Acuáticos (LEMVA), Departamento de Ciencias Biológicas, Universidad de los Andes, 18A-10 Bogotá, Colombia
| | | | - So Kawaguchi
- Australian Antarctic Division, Kingston, TAS, Australia
| | | | - Elanor M Bell
- Australian Antarctic Division, Kingston, TAS, Australia
| | - Ryosuke Makabe
- National Institute of Polar Research, 10-3 Midoricho, Tachikawa, Tokyo 190-8518, Japan; Department of Ocean Sciences, Tokyo University of Marine Science and Technology, 4-5-7Konan, Minato-ku, Tokyo 108-8477, Japan; Department of Polar Science, The Graduate University for Advanced Studies, SOKENDAI, 10-3, Midori-cho, Tachikawa, Tokyo 190-851, Japan
| | - Masato Moteki
- National Institute of Polar Research, 10-3 Midoricho, Tachikawa, Tokyo 190-8518, Japan; Department of Ocean Sciences, Tokyo University of Marine Science and Technology, 4-5-7Konan, Minato-ku, Tokyo 108-8477, Japan
| | - Nils Hoem
- Aker BioMarine Antarctic AS, NO-1327 Lysaker, Norway
| | - Brian Fry
- Australian Rivers Institute, Griffith University, 4111 Nathan, QLD, Australia
| | - Michele Burford
- Australian Rivers Institute, Griffith University, 4111 Nathan, QLD, Australia
| | - Susan Bengtson Nash
- Centre for Planetary Health and Food Security, Southern Ocean Persistent Organic Pollutants Program, Griffith University, 4111 Nathan, QLD, Australia
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Möller L, Vainshtein Y, Meyer B, Neidhardt J, Eren AM, Sohn K, Rabus R. Rich microbial and depolymerising diversity in Antarctic krill gut. Microbiol Spectr 2024; 12:e0403523. [PMID: 38466097 PMCID: PMC10986584 DOI: 10.1128/spectrum.04035-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Accepted: 02/13/2024] [Indexed: 03/12/2024] Open
Abstract
With almost a quadrillion individuals, the Antarctic krill processes five million tons of organic carbon every day during austral summer. This high carbon flux requires a broad range of hydrolytic enzymes to decompose the diverse food-derived biopolymers. While krill itself possesses numerous such enzymes, it is unclear, to what extent the endogenous microbiota contribute to the hydrolytic potential of the gut environment. Here we applied amplicon sequencing, shotgun metagenomics, cultivation, and physiological assays to characterize the krill gut microbiota. The broad bacterial diversity (273 families, 919 genera, and 2,309 species) also included a complex potentially anaerobic sub-community. Plate-based assays with 198 isolated pure cultures revealed widespread capacities to utilize lipids (e.g., tributyrin), followed by proteins (casein) and to a lesser extent by polysaccharides (e.g., alginate and chitin). While most isolates affiliated with the genera Pseudoalteromonas and Psychrobacter, also Rubritalea spp. (Verrucomicrobia) were observed. The krill gut microbiota growing on marine broth agar plates possess 13,012 predicted hydrolyses; 15-fold more than previously predicted from a transcriptome-proteome compendium of krill. Cultivation-independent and -dependent approaches indicated members of the families Flavobacteriaceae and Pseudoalteromonadaceae to dominate the capacities for lipid/protein hydrolysis and to provide a plethora of carbohydrate-active enzymes, sulfatases, and laminarin- or porphyrin-depolymerizing hydrolases. Notably, also the potential to hydrolyze plastics such as polyethylene terephthalate and polylactatide was observed, affiliating mostly with Moraxellaceae. Overall, this study shows extensive microbial diversity in the krill gut, and suggests that the microbiota likely play a significant role in the nutrient acquisition of the krill by enriching its hydrolytic enzyme repertoire.IMPORTANCEThe Antarctic krill (Euphausia superba) is a keystone species of the Antarctic marine food web, connecting the productivity of phyto- and zooplankton with the nutrition of the higher trophic levels. Accordingly, krill significantly contributes to biomass turnover, requiring the decomposition of seasonally varying plankton-derived biopolymers. This study highlights the likely role of the krill gut microbiota in this ecosystem function by revealing the great number of diverse hydrolases that microbes contribute to the krill gut environment. The here resolved repertoire of hydrolytic enzymes could contribute to the overall nutritional resilience of krill and to the general organic matter cycling under changing environmental conditions in the Antarctic sea water. Furthermore, the krill gut microbiome could serve as a valuable resource of cold-adapted hydrolytic enzymes for diverse biotechnological applications.
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Affiliation(s)
- Lars Möller
- Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
| | - Yevhen Vainshtein
- In Vitro Diagnostics, Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB), Stuttgart, Germany
| | - Bettina Meyer
- Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
- Helmholtz Institute for Functional Marine Biodiversity at the University Oldenburg (HIFMB), Oldenburg, Germany
- Biosciences, Alfred Wegener Institute (AWI), Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - John Neidhardt
- Department of Human Medicine, Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
- Research Center Neurosensory Science, Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
| | - A. Murat Eren
- Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
- Helmholtz Institute for Functional Marine Biodiversity at the University Oldenburg (HIFMB), Oldenburg, Germany
- HIFMB-MPG Bridging Group for Marine Genomics, Max Planck Institute for Marine Microbiology, Bremen, Germany
- Alfred Wegener Institute (AWI), Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany
| | - Kai Sohn
- In Vitro Diagnostics, Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB), Stuttgart, Germany
| | - Ralf Rabus
- Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
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Primpke S, Meyer B, Falcou-Préfol M, Schütte W, Gerdts G. At second glance: The importance of strict quality control - A case study on microplastic in the Southern Ocean key species Antarctic krill, Euphausia superba. Sci Total Environ 2024; 918:170618. [PMID: 38325470 DOI: 10.1016/j.scitotenv.2024.170618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 01/30/2024] [Accepted: 01/30/2024] [Indexed: 02/09/2024]
Abstract
The stomach content of 60 krill specimens from the Southern Ocean were analyzed for the presence of microplastic (MP), by testing different sample volumes, extraction approaches, and applying hyperspectral imaging Fourier-transform infrared spectroscopy (μFTIR). Strict quality control was applied on the generated results. A high load of residual materials in pooled samples hampered the analysis and avoided a reliable determination of putative MP particles. Individual krill stomachs displayed reliable results, however, only after re-treating the samples with hydrogen peroxide. Before this treatment, lipid rich residues of krill resulted in false assignments of polymer categories and hence, false high MP particle numbers. Finally, MP was identified in 4 stomachs out of 60, with only one MP particle per stomach. Our study highlights the importance of strict quality control to verify results before coming to a final decision on MP contamination in the environment to aid the establishment of suitable internationally standardized protocols for sampling and analysis of MP in organisms including their habitats in Southern Ocean and worldwide.
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Affiliation(s)
- Sebastian Primpke
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Division Shelf Sea System Ecology, Biologische Anstalt Helgoland, Kurpromenade, 27498 Helgoland, Germany.
| | - Bettina Meyer
- Alfred Wegener Institute for Polar and Marine Research, Division Polar Biological Oceanography, Am Handelshafen 12, 27570 Bremerhaven, Germany; Carl-von-Ossietzky University Oldenburg, Institute for Chemistry and Biology of the Marine Environment, Ammerländer Heerstraße 114-118, 26129 Oldenburg, Germany; Helmholtz Institute for Functional Marine Biodiversity (HIFMB) at the Carl-von-Ossietzky University, Oldenburg 26111, Germany.
| | - Mathilde Falcou-Préfol
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Division Shelf Sea System Ecology, Biologische Anstalt Helgoland, Kurpromenade, 27498 Helgoland, Germany; Alfred Wegener Institute for Polar and Marine Research, Division Polar Biological Oceanography, Am Handelshafen 12, 27570 Bremerhaven, Germany; Nantes Université, 1 Quai de Tourville, 44035 Nantes Cedex 1, France
| | - Wyona Schütte
- Alfred Wegener Institute for Polar and Marine Research, Division Polar Biological Oceanography, Am Handelshafen 12, 27570 Bremerhaven, Germany; Carl-von-Ossietzky University Oldenburg, Institute for Chemistry and Biology of the Marine Environment, Ammerländer Heerstraße 114-118, 26129 Oldenburg, Germany
| | - Gunnar Gerdts
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Division Shelf Sea System Ecology, Biologische Anstalt Helgoland, Kurpromenade, 27498 Helgoland, Germany
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Ouled-Cheikh J, March D, Borras-Chavez R, Drago M, Goebel ME, Fariña JM, Gazo M, Coll M, Cardona L. Future climate-induced distribution shifts in a sexually dimorphic key predator of the Southern Ocean. Glob Chang Biol 2024; 30:e17191. [PMID: 38433338 DOI: 10.1111/gcb.17191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 12/20/2023] [Accepted: 12/21/2023] [Indexed: 03/05/2024]
Abstract
The response to climate change in highly dimorphic species can be hindered by differences between sexes in habitat preferences and movement patterns. The Antarctic fur seal, Arctocephalus gazella, is the most abundant pinniped in the Southern Hemisphere, and one of the main consumers of Antarctic krill, Euphausia superba, in the Southern Ocean. However, the populations breeding in the Atlantic Southern Ocean are decreasing, partly due to global warming. Male and female Antarctic fur seals differ greatly in body size and foraging ecology, and little is known about their sex-specific responses to climate change. We used satellite tracking data and Earth System Models to predict changes in habitat suitability for male and female Antarctic fur seals from the Western Antarctic Peninsula under different climate change scenarios. Under the most extreme scenario (SSP5-8.5; global average temperature +4.4°C projected by 2100), suitable habitat patches will shift southward during the non-breeding season, leading to a minor overall habitat loss. The impact will be more pronounced for females than for males. The reduction of winter foraging grounds might decrease the survival of post-weaned females, reducing recruitment and jeopardizing population viability. During the breeding season, when males fast on land, suitable foraging grounds for females off the South Shetland Islands will remain largely unmodified, and new ones will emerge in the Bellingshausen Sea. As Antarctic fur seals are income breeders, the foraging grounds of females should be reasonably close to the breeding colony. As a result, the new suitable foraging grounds will be useful for females only if nearby beaches currently covered by sea ice emerge by the end of the century. Furthermore, the colonization of these new, ice-free breeding locations might be limited by strong female philopatry. These results should be considered when managing the fisheries of Antarctic krill in the Southern Ocean.
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Affiliation(s)
- Jazel Ouled-Cheikh
- Institut de Recerca de la Biodiversitat (IRBio) and Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals (BEECA), Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
- iMARES group, Departament de Recursos Marins Renovables, Institut de Ciències del Mar (ICM-CSIC), Barcelona, Spain
| | - David March
- Institut Cavanilles de Biodiversitat i Biologia Evolutiva (ICBiBE), Universitat de València, Paterna, València, Spain
- Centre for Ecology and Conservation, College of Life and Environmental Science, University of Exeter, Penryn, Cornwall, UK
| | - Renato Borras-Chavez
- Center of Applied Ecology and Sustainability (CAPES), Pontificia Universidad Católica de Chile, Santiago, Chile
- Department of Biology, Baylor University, Waco, Texas, USA
| | - Massimiliano Drago
- Institut de Recerca de la Biodiversitat (IRBio) and Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals (BEECA), Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Michael E Goebel
- Institute of Marine Sciences, University of California Santa Cruz (UCSC), Santa Cruz, California, USA
- Antarctic Ecosystem Research Division, SWFSC, NMFS, NOAA, La Jolla, California, USA
| | - José M Fariña
- Center of Applied Ecology and Sustainability (CAPES), Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Manel Gazo
- Institut de Recerca de la Biodiversitat (IRBio) and Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals (BEECA), Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Marta Coll
- iMARES group, Departament de Recursos Marins Renovables, Institut de Ciències del Mar (ICM-CSIC), Barcelona, Spain
- Ecopath International Initiative (EII), Barcelona, Spain
| | - Luis Cardona
- Institut de Recerca de la Biodiversitat (IRBio) and Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals (BEECA), Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
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7
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Forcada J, Hoffman JI, Gimenez O, Staniland IJ, Bucktrout P, Wood AG. Ninety years of change, from commercial extinction to recovery, range expansion and decline for Antarctic fur seals at South Georgia. Glob Chang Biol 2023; 29:6867-6887. [PMID: 37839801 DOI: 10.1111/gcb.16947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 09/04/2023] [Accepted: 09/05/2023] [Indexed: 10/17/2023]
Abstract
With environmental change, understanding how species recover from overharvesting and maintain viable populations is central to ecosystem restoration. Here, we reconstruct 90 years of recovery trajectory of the Antarctic fur seal at South Georgia (S.W. Atlantic), a key indicator species in the krill-based food webs of the Southern Ocean. After being harvested to commercial extinction by 1907, this population rebounded and now constitutes the most abundant otariid in the World. However, its status remains uncertain due to insufficient and conflicting data, and anthropogenic pressures affecting Antarctic krill, an essential staple for millions of fur seals and other predators. Using integrated population models, we estimated simultaneously the long-term abundance for Bird Island, northwest South Georgia, epicentre of recovery of the species after sealing, and population adjustments for survey counts with spatiotemporal applicability. Applied to the latest comprehensive survey data, we estimated the population at South Georgia in 2007-2009 as 3,510,283 fur seals [95% CI: 3,140,548-3,919,604] (ca. 98% of global population), after 40 years of maximum growth and range expansion owing to an abundant krill supply. At Bird Island, after 50 years of exponential growth followed by 25 years of slow stable growth, the population collapsed in 2009 and has thereafter declined by -7.2% [-5.2, -9.1] per annum, to levels of the 1970s. For the instrumental record, this trajectory correlates with a time-varying relationship between coupled climate and sea surface temperature cycles associated with low regional krill availability, although the effects of increasing krill extraction by commercial fishing and natural competitors remain uncertain. Since 2015, fur seal longevity and recruitment have dropped, sexual maturation has retarded, and population growth is expected to remain mostly negative and highly variable. Our analysis documents the rise and fall of a key Southern Ocean predator over a century of profound environmental and ecosystem change.
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Affiliation(s)
- Jaume Forcada
- British Antarctic Survey, Natural Environment Research Council, UKRI, Cambridge, UK
| | - Joseph I Hoffman
- British Antarctic Survey, Natural Environment Research Council, UKRI, Cambridge, UK
- Department of Animal Behavior, University of Bielefeld, Bielefeld, Germany
| | - Olivier Gimenez
- CEFE, CNRS, Univ Montpellier, EPHE, IRD, Montpellier, France
| | | | - Pete Bucktrout
- British Antarctic Survey, Natural Environment Research Council, UKRI, Cambridge, UK
| | - Andrew G Wood
- British Antarctic Survey, Natural Environment Research Council, UKRI, Cambridge, UK
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8
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Wang S, Lin S, Liu K, Liu Y, Liu Q, Sun N. Digestion-Resistant Linear Epitopes as Dominant Contributors to Strong Allergenicity of Tropomyosin in Antarctic Krill ( Euphausia superba). J Agric Food Chem 2023; 71:16739-16751. [PMID: 37897700 DOI: 10.1021/acs.jafc.3c04999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/30/2023]
Abstract
Although tropomyosin has been identified as a major allergen in Antarctic krill, the digestive fate of Antarctic krill tropomyosin and its relationship with allergenicity are unknown. In this study, Antarctic krill tropomyosin was administered to BALB/c mice via both gavage and intraperitoneal injection to explore its sensitizing and eliciting capacity, and its digestion products were analyzed for structural changes and digestion-resistant linear epitopes. Mice gavaged with tropomyosin exhibited lower levels of specific IgE and IgG1, mast cell degranulation, vascular permeability, and anaphylaxis symptoms than those in the intraperitoneal injection group. This may be due to the destruction of macromolecular aggregates, loose expansion of the tertiary structure, complete disappearance of α-helix, and significant changes in molecular force upon the digestion of tropomyosin. Nevertheless, the intragastric administration of Antarctic krill tropomyosin still triggered strong allergic reactions, which was attributed to the existence of seven digestion-resistant linear epitopes (Glu26-His44, Thr111-Arg125, Glu157-Glu164, Glu177-Gly186, Val209-Ile225, Arg244-Arg255, and Val261-Ile270).
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Affiliation(s)
- Shan Wang
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, P. R. China
| | - Songyi Lin
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, P. R. China
- Liaoning Engineering Research Center of Special Dietary Food, Dalian Polytechnic University, Dalian 116034, P. R. China
| | - Kexin Liu
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, P. R. China
| | - Yao Liu
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, P. R. China
| | - Qiaozhen Liu
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, P. R. China
| | - Na Sun
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, P. R. China
- Liaoning Engineering Research Center of Special Dietary Food, Dalian Polytechnic University, Dalian 116034, P. R. China
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9
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Feng Z, Wang Y, Ma L, Huang S, Wang L, He J, Guo C. Genomic Characteristics and Functional Analysis of Brucella sp. Strain WY7 Isolated from Antarctic Krill. Microorganisms 2023; 11:2281. [PMID: 37764125 PMCID: PMC10536100 DOI: 10.3390/microorganisms11092281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Revised: 09/07/2023] [Accepted: 09/08/2023] [Indexed: 09/29/2023] Open
Abstract
Antarctic krill (Euphausia superba) is a key species of the Antarctic ecosystem whose unique ecological status and great development potential have attracted extensive attention. However, the genomic characteristics and potential biological functions of the symbiotic microorganisms of Antarctic krill remain unknown. In this study, we cultured and identified a strain of Brucella sp. WY7 from Antarctic krill using whole-genome sequencing and assembly, functional annotation, and comparative genomics analysis. First, based on 16S rDNA sequence alignment and phylogenetic tree analysis, we identified strain WY7 as Brucella. The assembled genome of strain WY7 revealed that it has two chromosomes and a plasmid, with a total genome length of 4,698,850 bp and an average G + C content of 57.18%. The DNA-DNA hybridization value and average nucleotide identity value of strain WY7 and Brucella anthropi ATCC® 49188TM, a type strain isolated from human clinical specimens, were 94.8% and 99.07%, respectively, indicating that strain WY7 is closely related to Brucella anthropi. Genomic island prediction showed that the strain has 60 genomic islands, which may produce HigB and VapC toxins. AntiSMASH analysis results showed that strain WY7 might produce many secondary metabolites, such as terpenes, siderophores and ectoine. Moreover, the genome contains genes involved in the degradation of aromatic compounds, suggesting that strain WY7 can use aromatic compounds in its metabolism. Our work will help to understand the genomic characteristics and metabolic potential of bacterial strains isolated from Antarctic krill, thereby revealing their roles in Antarctic krill and marine ecosystems.
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Affiliation(s)
- Zhengqi Feng
- State Key Laboratory for Biocontrol and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Marine Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, China; (Z.F.); (Y.W.); (S.H.); (J.H.)
| | - Yuanyuan Wang
- State Key Laboratory for Biocontrol and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Marine Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, China; (Z.F.); (Y.W.); (S.H.); (J.H.)
| | - Lingbo Ma
- Key Laboratory of the East China Sea and Oceanic Fishery Resources Exploitation, Ministry of Agriculture, East China Sea Fisheries Research Institute, Shanghai 116023, China; (L.M.); (L.W.)
| | - Shanzi Huang
- State Key Laboratory for Biocontrol and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Marine Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, China; (Z.F.); (Y.W.); (S.H.); (J.H.)
| | - Lumin Wang
- Key Laboratory of the East China Sea and Oceanic Fishery Resources Exploitation, Ministry of Agriculture, East China Sea Fisheries Research Institute, Shanghai 116023, China; (L.M.); (L.W.)
| | - Jianguo He
- State Key Laboratory for Biocontrol and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Marine Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, China; (Z.F.); (Y.W.); (S.H.); (J.H.)
- Guangdong Province Key Laboratory for Aquatic Economic Animals, and Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, China
| | - Changjun Guo
- State Key Laboratory for Biocontrol and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Marine Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, China; (Z.F.); (Y.W.); (S.H.); (J.H.)
- Guangdong Province Key Laboratory for Aquatic Economic Animals, and Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, China
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10
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Bahlburg D, Hüppe L, Böhrer T, Thorpe SE, Murphy EJ, Berger U, Meyer B. Plasticity and seasonality of the vertical migration behaviour of Antarctic krill using acoustic data from fishing vessels. R Soc Open Sci 2023; 10:230520. [PMID: 37771962 PMCID: PMC10523065 DOI: 10.1098/rsos.230520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 09/06/2023] [Indexed: 09/30/2023]
Abstract
Understanding the vertical migration behaviour of Antarctic krill is important for understanding spatial distribution, ecophysiology, trophic interactions and carbon fluxes of this Southern Ocean key species. In this study, we analysed an eight-month continuous dataset recorded with an ES80 echosounder on board a commercial krill fishing vessel in the southwest Atlantic sector of the Southern Ocean. Our analysis supports the existing hypothesis that krill swarms migrate into deeper waters during winter but also reveals a high degree of variability in vertical migration behaviour within seasons, even at small spatial scales. During summer, we found that behaviour associated with prolonged surface presence primarily occurred at low surface chlorophyll a concentrations whereas multiple ascent-descent cycles per day occurred when surface chlorophyll a concentrations were elevated. The high plasticity, with some krill swarms behaving differently in the same location at the same time, suggests that krill behaviour is not a purely environmentally driven process. Differences in life stage, physiology and type of predator are likely other important drivers. Finally, our study demonstrates new ways of using data from krill fishing vessels, and with the routine collection of additional information in potential future projects, they have great potential to significantly advance our understanding of krill ecology.
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Affiliation(s)
- Dominik Bahlburg
- Forstliche Biometrie und Systemanalyse, Technische Universität Dresden, Pienner Straße 8, 01737 Tharandt, Dresden, Germany
- Helmholtz Centre for Environmental Research Leipzig, Permoserstraße 15, 04318 Leipzig, Germany
| | - Lukas Hüppe
- Neurobiology and Genetics, Julius-Maximilian-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Alfred-Wegener-Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - Thomas Böhrer
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Schloßplatz 4, 91054 Erlangen, Germany
| | - Sally E. Thorpe
- Ecosystems, British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK
| | - Eugene J. Murphy
- Ecosystems, British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK
| | - Uta Berger
- Forstliche Biometrie und Systemanalyse, Technische Universität Dresden, Pienner Straße 8, 01737 Tharandt, Dresden, Germany
| | - Bettina Meyer
- Alfred-Wegener-Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
- Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26111 Oldenburg, Germany
- Helmholtz Institute for Functional Marine Biodiversity, Ammerländer Heerstraße 231, 26129 Oldenburg, Germany
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11
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Li S, Lin S, Jiang P, Feng Q, Bao Z, Huang Y, Sun N. Discovery of Potential Protein Markers Associated with Quality Characteristics of Antarctic Krill ( Euphausia superba) Surimi Gel. J Agric Food Chem 2023. [PMID: 37478023 DOI: 10.1021/acs.jafc.3c02860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/23/2023]
Abstract
Antarctic krill are a consumption resource with great exploitation potential. However, the poor gel properties of Antarctic krill meat seriously limit its high-value application. In the present study, the quality characteristics and proteome changes of the κ-/ι-carrageenan-Antarctic krill surimi gel were systematically analyzed and compared. In addition, the transcriptome sequencing of Antarctic krill was carried out, which filled the gap in the Antarctic krill database. Higher molecular forces (disulfide bond and hydrophobic interaction) and the degree of network cross-linking significantly promoted the formation of κ/ι-carrageenan-Antarctic krill surimi compared to that of Antarctic krill surimi. This is the first study to investigate and map potential protein markers for quality characteristics of Antarctic krill surimi based on mass spectrometry-based label-free quantitative proteomics. The results could provide a theoretical reference for the quality control of Antarctic krill during application.
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Affiliation(s)
- Shuang Li
- National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, P. R. China
| | - Songyi Lin
- National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, P. R. China
- State Key Laboratory of Marine Food Processing and Safety Control, Dalian Polytechnic University, Dalian 116034, P. R. China
| | - Pengfei Jiang
- National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, P. R. China
- State Key Laboratory of Marine Food Processing and Safety Control, Dalian Polytechnic University, Dalian 116034, P. R. China
| | - Qi Feng
- National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, P. R. China
| | - Zhijie Bao
- National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, P. R. China
- State Key Laboratory of Marine Food Processing and Safety Control, Dalian Polytechnic University, Dalian 116034, P. R. China
| | - Yihan Huang
- National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, P. R. China
| | - Na Sun
- National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, P. R. China
- State Key Laboratory of Marine Food Processing and Safety Control, Dalian Polytechnic University, Dalian 116034, P. R. China
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12
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Lin N, Chi H, Ni L, Zhang H, Liu Z. Study on the Sensitization and Antigenic Epitopes of Tropomyosin from Antarctic Krill ( Euphausia superba). J Agric Food Chem 2023; 71:6445-6457. [PMID: 37057995 DOI: 10.1021/acs.jafc.3c00159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Antarctic krill (Euphausia superba), a shrimp-like marine crustacean, has become a beneficial source of high-quality animal protein. Meanwhile, a special focus has been placed on its potential sensitization issue. In this study, a 35 kDa protein was purified and identified to be Antarctic krill tropomyosin (AkTM) by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The purified TM showed a strong IgE-binding capacity to shrimp/crab-allergic patients' sera, indicating that TM is the primary allergen in Antarctic krill. Simulated gastrointestinal digestion revealed that the digestion stability of TM to pepsin was higher than that to trypsin. The strong degranulation triggered by TM in RBL-2H3 cells suggested that AkTM has a strong sensitization capacity. The TM-sensitized BALB/c mice displayed severe anaphylactic symptoms; high levels of TM-specific IgE, sIgG1, and histamine; and increased IL-4, indicating that AkTM could provoke IgE-mediated allergic reactions. Bioinformatics prediction, indirect competition ELISA, and mast cell degranulation assay were used to map the antigenic epitopes of AkTM. Finally, nine peptides of T43-58, T88-101, T111-125, T133-143, T144-155, T183-197, T223-236, T249-261, and T263-281 were identified as the linear epitopes of AkTM. The findings may help us develop efficient food processing techniques to reduce krill allergy and gain a deeper comprehension of the allergenicity of krill allergens.
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Affiliation(s)
- Na Lin
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China
| | - Hai Chi
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China
| | - Ling Ni
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China
| | - Hong Zhang
- School of Food Science and Biological Engineering, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, China
| | - Zhidong Liu
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China
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13
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Zhu W, Liu W, Chen Y, Liao K, Yu W, Jin H. Microplastics in Antarctic krill (Euphausia superba) from Antarctic region. Sci Total Environ 2023; 870:161880. [PMID: 36731553 DOI: 10.1016/j.scitotenv.2023.161880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 01/24/2023] [Accepted: 01/24/2023] [Indexed: 06/18/2023]
Abstract
Pollution of microplastics (MPs) has become a potential threat to Antarctic marine ecosystems. However, the occurrence of MPs in Antarctic krill (Euphausia superba), a keystone species in Antarctic ecosystems, remains unclear. In this study, the abundance and characteristics of MPs were examined in Antarctic krill samples (n = 437) collected from two Antarctic regions. MPs were extracted using an alkali digestion method and analyzed using Fourier-transform infrared spectroscopy. The mean abundance of MPs in Antarctic krill samples from the South Shetland Islands (n = 355) and the South Orkney Islands (n = 82) were 0.29 ± 0.14 and 0.20 ± 0.083 items/individual, respectively. >90 % of MPs found in Antarctic krill were < 150 μm in size. Fibers represented 77 % and 87 % of the MPs in Antarctic krill samples from the South Shetland Islands and the South Orkney Islands, respectively. Black, blue, and red were the predominant colors of MPs in Antarctic krill, accounting for 32 %, 22 %, and 21 % of the total MPs, respectively. Seven polymer compositions were identified for the MPs in Antarctic krill, with the predominance of polyethylene (37 % of total MPs), followed by polypropylene (22 %) and polyester (21 %). To our knowledge, this is the first study to investigate the occurrence of MPs in Antarctic krill samples. The results of this study are important for evaluating the risks of MP exposure in Antarctic krill.
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Affiliation(s)
- Wenbin Zhu
- Zhejiang Marine Fisheries Research Institute, Scientific Observing and Experimental Station of Fishery Resources for Key Fishing Grounds, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Key Laboratory of Sustainable Utilization of Technology Research for Fishery Resources of Zhejiang Province, Zhoushan, Zhejiang 316021, PR China
| | - Wenbo Liu
- Zhejiang Marine Fisheries Research Institute, Scientific Observing and Experimental Station of Fishery Resources for Key Fishing Grounds, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Key Laboratory of Sustainable Utilization of Technology Research for Fishery Resources of Zhejiang Province, Zhoushan, Zhejiang 316021, PR China
| | - Yuanchen Chen
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, PR China
| | - Kaizhen Liao
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, PR China
| | - Wenfei Yu
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, PR China
| | - Hangbiao Jin
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, PR China.
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14
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Gao Y, Yang L, Liu H, Xie Z. Positive Atlantic Multidecadal Oscillation has driven poleward redistribution of the West Antarctic Peninsula biota through a food-chain mechanism. Sci Total Environ 2023; 881:163373. [PMID: 37044333 DOI: 10.1016/j.scitotenv.2023.163373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 04/02/2023] [Accepted: 04/04/2023] [Indexed: 04/14/2023]
Abstract
The West Antarctic Peninsula (WAP) has recorded a significant poleward range shift in marine biota, including Adélie penguins, Antarctic krill and phytoplankton. The ecological changes have been widely attributed to Pacific/Southern Hemisphere variabilities. However, the teleconnection from the North Atlantic Ocean, which also could induce changes in the WAP physical environments, has been overlooked. Here we combine state-of-the-art observational/modelling databases to quantify the poleward redistribution since the 1980s of three key members of the WAP biota and explored their response to several climatic oscillations. The abundance of Adélie penguins, Antarctic krill and phytoplankton in the WAP all show a decrease in the north and an increase in the south, leading to a poleward shift of their distribution centers by ~0.8-2.3°. A more positive Atlantic Multidecadal Oscillation (AMO) has contributed to the poleward redistribution of phytoplankton/krill/penguin with a time lag of 0/1/5 yr, indicating a food-chain related mechanism. +AMO in spring resulted in reduced sea ice, earlier ice retreat and enhanced winds in the northern WAP, which constrained phytoplankton blooms and krill reproduction, thereby decreasing the krill recruitment 1 yr later and consequently the penguin recruitment 5 yr later. In the southern WAP, where the sea ice cover was nearly permanent in the 1980s, reduced sea ice and earlier ice retreat promoted phytoplankton growth and krill/penguin reproduction. Our results emphasize the global nature of climate-ecological coupling; the influence of the Northern Hemisphere climate system on Antarctic/Southern Ocean biota is a non-negligible factor for the ecosystem management.
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Affiliation(s)
- Yuesong Gao
- Institute of Polar Environment, Anhui Key Laboratory of Polar Environment and Global Change, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, Anhui, China
| | - Lianjiao Yang
- Institute of Polar Environment, Anhui Key Laboratory of Polar Environment and Global Change, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, Anhui, China
| | - Hongwei Liu
- Institute of Polar Environment, Anhui Key Laboratory of Polar Environment and Global Change, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, Anhui, China
| | - Zhouqing Xie
- Institute of Polar Environment, Anhui Key Laboratory of Polar Environment and Global Change, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, Anhui, China.
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15
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Shi T, Li YJ, Wang ZM, Wang YF, Wang B, Shi DY. New Pyrroline Isolated from Antarctic Krill-Derived Actinomycetes Nocardiopsis sp. LX-1 Combining with Molecular Networking. Mar Drugs 2023; 21:md21020127. [PMID: 36827168 PMCID: PMC9967698 DOI: 10.3390/md21020127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 02/10/2023] [Accepted: 02/14/2023] [Indexed: 02/17/2023] Open
Abstract
Antarctic krill (Euphausia superba) of the Euphausiidae family comprise one of the largest biomasses in the world and play a key role in the Antarctic marine ecosystem. However, the study of E. superba-derived microbes and their secondary metabolites has been limited. Chemical investigation of the secondary metabolites of the actinomycetes Nocardiopsis sp. LX-1 (in the family of Nocardiopsaceae), isolated from E. superba, combined with molecular networking, led to the identification of 16 compounds a-p (purple nodes in the molecular network) and the isolation of one new pyrroline, nocarpyrroline A (1), along with 11 known compounds 2-12. The structure of the new compound 1 was elucidated by extensive spectroscopic investigation. Compound 2 exhibited broad-spectrum antibacterial activities against A. hydrophila, D. chrysanthemi, C. terrigena, X. citri pv. malvacearum and antifungal activity against C. albicans in a conventional broth dilution assay. The positive control was ciprofloxacin with the MIC values of <0.024 µM, 0.39 µM, 0.39 µM, 0.39 µM, and 0.20 µM, respectively. Compound 1 and compounds 7, 10, and 11 displayed antifungal activities against F. fujikuroi and D. citri, respectively, in modified agar diffusion test. Prochloraz was used as positive control and showed the inhibition zone radius of 17 mm and 15 mm against F. fujikuroi and D. citri, respectively. All the annotated compounds a-p by molecular networking were first discovered from the genus Nocardiopsis. Nocarpyrroline A (1) features an unprecedented 4,5-dihydro-pyrrole-2-carbonitrile substructure, and it is the first pyrroline isolated from the genus Nocardiopsis. This study further demonstrated the guiding significance of molecular networking in the research of microbial secondary metabolites.
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Affiliation(s)
- Ting Shi
- College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao 266590, China
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Yan-Jing Li
- College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao 266590, China
| | - Ze-Min Wang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Yi-Fei Wang
- College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao 266590, China
| | - Bo Wang
- College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao 266590, China
- Correspondence: (B.W.); (D.-Y.S.)
| | - Da-Yong Shi
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, China
- Correspondence: (B.W.); (D.-Y.S.)
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16
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Shang S, Liu Y, Jiang P, Wang Y, Fu B, Qi L. Effects of partial replacement of unwashed Antarctic krill surimi by Litopenaeus vannamei surimi on the heat-induced gelling and three-dimensional-printing properties. J Texture Stud 2023; 54:299-310. [PMID: 36598068 DOI: 10.1111/jtxs.12739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 12/23/2022] [Accepted: 01/01/2023] [Indexed: 01/05/2023]
Abstract
There is an emerging consumption of the Antarctic krill (AK) muscle-based food due to its excellent nutritional value and enormous biomass storage capacity. However, the coarse texture of the muscle and the weak gelling properties of AK protein impede its expansion in surimi-based products. This investigation successfully prepared heat-induced gels of AK surimi with desirable textural properties by including Litopenaeus vannamei in varying proportions. Higher concentrations of L. vannamei resulted in improved three-dimensional printability, greater water-holding capacity (WHC), larger viscoelastic modulus, and a well-formed microstructural matrix of AK surimi, due to an increased level of myofibrillar protein. Compared with AK, L. vannamei muscle had double the salt-soluble protein content, which was corroborated by increased intensity of bands of actin, paramyosin, tropomyosin, and myosin light chains on reducing SDS-PAGE. DSC results indicated that a high ratio of L. vannamei elevated the denaturation temperature and enthalpy of myosin, sarcoplasmic protein, and actin, suggesting a high degree of cross-linking. It was also found that when hydroxypropyl cassava starch was added at 0.5% (w/w), WHC and gel strength were further improved with a more compact gel matrix. The successful preparation of unwashed mixed surimi with AK meat fully exploited in this study provides an option for AK surimi-based product industrialization.
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Affiliation(s)
- Shan Shang
- Collaborative Innovation Centre of Provincial and Ministerial Co-construction for Seafood Deep Processing, National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian, China
| | - Ying Liu
- Collaborative Innovation Centre of Provincial and Ministerial Co-construction for Seafood Deep Processing, National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian, China
| | - Pengfei Jiang
- Collaborative Innovation Centre of Provincial and Ministerial Co-construction for Seafood Deep Processing, National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian, China
| | - Yueyue Wang
- Collaborative Innovation Centre of Provincial and Ministerial Co-construction for Seafood Deep Processing, National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian, China
| | - Baoshang Fu
- Collaborative Innovation Centre of Provincial and Ministerial Co-construction for Seafood Deep Processing, National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian, China
| | - Libo Qi
- Collaborative Innovation Centre of Provincial and Ministerial Co-construction for Seafood Deep Processing, National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian, China
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17
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Watters GM, Hinke JT. Conservation in the Scotia Sea in light of expiring regulations and disrupted negotiations. Conserv Biol 2022; 36:e13925. [PMID: 35451530 PMCID: PMC9790540 DOI: 10.1111/cobi.13925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 03/17/2022] [Accepted: 03/28/2022] [Indexed: 06/14/2023]
Affiliation(s)
- George M. Watters
- Antarctic Ecosystem Research DivisionSouthwest Fisheries Science CenterNational Marine Fisheries Service, National Oceanic and Atmospheric AdministrationLa JollaCaliforniaUSA
| | - Jefferson T. Hinke
- Antarctic Ecosystem Research DivisionSouthwest Fisheries Science CenterNational Marine Fisheries Service, National Oceanic and Atmospheric AdministrationLa JollaCaliforniaUSA
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18
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Li S, Lin S, Jiang P, Bao Z, Li S, Sun N. Insight into the Gel Properties of Antarctic Krill and Pacific White Shrimp Surimi Gels and the Feasibility of Polysaccharides as Texture Enhancers of Antarctic Krill Surimi Gels. Foods 2022; 11:foods11162517. [PMID: 36010517 PMCID: PMC9407480 DOI: 10.3390/foods11162517] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 08/17/2022] [Accepted: 08/17/2022] [Indexed: 11/16/2022] Open
Abstract
Antarctic krill is a potential and attractive resource for consumption. However, most Antarctic krill meat is used to produce primary products with low commercial value, with few highly processed products. This study aimed to evaluate and improve the gelling properties of Antarctic krill surimi, with Pacific white shrimp surimi as control. Compared with Pacific white shrimp surimi, the lower β-sheet content and protein aggregation degree had a severe impact on the formation of the gel network of Antarctic krill surimi, which resulted in weaker breaking force, gel strength, and viscoelasticity (p < 0.05). Moreover, water retention capacity and molecular forces had a positive effect on the stability of the gel matrix of shrimp surimi. Thus, the high α-helix/β-sheet ratio, weak intermolecular interactions, and low level of protein network cross-linkage were the main reasons for the poor quality of Antarctic krill surimi. On this basis, the effects of six polysaccharides on the texture properties of Antarctic krill surimi were studied. Chitosan, konjac glucomannan, sodium carboxyl methyl cellulose, and waxy maize starch resulted in no significant improvement in the texture properties of Antarctic krill surimi (p > 0.05). However, the addition of ι-carrageenan (2%) or κ-carrageenan (1~2%) is an effective way to improve the texture properties of Antarctic krill surimi (p < 0.05). These findings will contribute to the development of reconstituted Antarctic krill surimi products with high nutritional quality and the promotion of deep-processing products of Antarctic krill meat.
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Affiliation(s)
- Shuang Li
- National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China
| | - Songyi Lin
- National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China
- Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian 116034, China
| | - Pengfei Jiang
- National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China
- Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian 116034, China
| | - Zhijie Bao
- National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China
- Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian 116034, China
| | - Sibo Li
- National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China
| | - Na Sun
- National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China
- Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian 116034, China
- Correspondence: ; Tel.: +86-411-86318753; Fax: +86-411-86318655
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19
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Bai J, Fan Y, Zhu L, Wang Y, Hou H. Characteristic flavor of Antarctic krill (Euphausia superba) and white shrimp (Penaeus vannamei) induced by thermal treatment. Food Chem 2022; 378:132074. [PMID: 35033714 DOI: 10.1016/j.foodchem.2022.132074] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 12/30/2021] [Accepted: 01/03/2022] [Indexed: 11/18/2022]
Abstract
For the good acceptance and preference of heated shrimp, characteristic flavor composition analysis was necessary. The sensory evaluation, electronic tongue, electronic nose, and gas chromatography-ion mobility spectrometry were employed in this study. After steaming or cooking, the sensory scores of Antarctic krill (KM) and white shrimp (PM) were significantly increased, and five basic tastes were remarkably changed by electronic tongue analysis. Free glycine level increased from 86.48 to 687.12 mg/100 g in PM after steaming, but no significant changes in KM. 5'-nucleotides in heated PM were higher than those in heated KM. In two kinds of shrimp, inorganic ions and lactic acids contents exhibited the decrease trends after cooking, and the response intensities of S4, S5, and S6 showed increase trends after steaming. Nonanal, benzaldehyde, (Z)-3-hexen-1-ol, 1-8-cineol and limonene were produced by thermal treatment. Therefore, characteristic flavor formation was related to thermal treatment.
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Affiliation(s)
- Jing Bai
- College of Food Science and Engineering, Ocean University of China, No. 5, Yu Shan Road, Qingdao, Shandong Province 266003, PR China
| | - Yan Fan
- College of Food Science and Engineering, Ocean University of China, No. 5, Yu Shan Road, Qingdao, Shandong Province 266003, PR China.
| | - Lulu Zhu
- College of Food Science and Engineering, Ocean University of China, No. 5, Yu Shan Road, Qingdao, Shandong Province 266003, PR China
| | - Yanchao Wang
- College of Food Science and Engineering, Ocean University of China, No. 5, Yu Shan Road, Qingdao, Shandong Province 266003, PR China
| | - Hu Hou
- College of Food Science and Engineering, Ocean University of China, No. 5, Yu Shan Road, Qingdao, Shandong Province 266003, PR China; Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong Province 266237, PR China.
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20
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Liu Y, Yu X, Zhu Y, Yang W, Zeng Y, Hu Y, Jiang W. Preparation, Characterization, and Mechanism of Antifreeze Peptides from Defatted Antarctic Krill (Euphausia superba) on Lactobacillus rhamnosus. Molecules 2022; 27. [PMID: 35566118 DOI: 10.3390/molecules27092771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 04/17/2022] [Accepted: 04/20/2022] [Indexed: 11/17/2022] Open
Abstract
Defatted Antarctic krill powder is the main by-product in the manufacturing of krill oil. Exploring a high value-added approach for utilizing this protein-rich material has received much attention in research and industry. Given this, the preparation and primary characterization of antifreeze peptides from defatted Antarctic krill (AKAPs) were carried out in this study. The cryoprotective effect of AKAPs on Lactobacillus rhamnosus ATCC7469 was also investigated. The results showed that Protamex was the optimum protease for AKAP preparation from defatted Antarctic krill. AKAPs were found to be rich in short peptides, with the MW ranging from 600 to 2000 Da (69.2%). An amino acid composition analysis showed that AKAPs were rich in glutamic acid (18.71%), aspartic acid (12.19%), leucine (7.87%), and lysine (7.61%). After freezing, the relative survival rate of Lactobacillus rhamnosus in the 1.0 mg/mL AKAP-treated group (96.83%) was significantly higher than in the saline group (24.12%) (p < 0.05). AKAPs also retarded the loss of acidifying activity of L. rhamnosus after freezing. AKAPs showed even better cryoprotective activity than three commercial cryoprotectants (sucrose, skim milk, and glycerol). In addition, AKAPs significantly alleviated the decrease in β-galactosidase and lactic dehydrogenase activities of L. rhamnosus (p < 0.05). Furthermore, AKAPs effectively protected the integrity of L. rhamnosus cell membranes from freezing damage and alleviated the leakage of intracellular substances. These findings demonstrate that AKAPs can be a potential cryoprotectant for preserving L. rhamnosus, providing a new way to use defatted Antarctic krill.
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21
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Xie J, Tao L, Wu Q, Bian Z, Wang M, Li Y, Zhu G, Lin T. Bioaccumulation of organochlorine pesticides in Antarctic krill (Euphausia superba): Profile, influencing factors, and mechanisms. J Hazard Mater 2022; 426:128115. [PMID: 34959217 DOI: 10.1016/j.jhazmat.2021.128115] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 12/15/2021] [Accepted: 12/16/2021] [Indexed: 06/14/2023]
Abstract
Accumulation of organochlorine pesticides (OCPs) in Antarctic krill (Euphausia superba), a keystone species in the Southern Ocean, is potentially harmful to the Antarctic ecosystem and human health. In the current study, we collected E. superba specimens (including muscle and carapace tissues) from Bransfield Strait in northern Antarctic Peninsula and South Georgia to analyze the profile, influencing factors and mechanisms of OCPs bioaccumulation in them. Results indicated that the biological traits (δ13C, δ15N and lipid contents) of krill were significantly affected by habitat. There may exist growth dilution of OCPs in Antarctic krill and no fresh OCPs input in Antarctica, except for endosulfan I. Based on lipid-normalized concentrations, no significant differences were observed between the two regions at most sampling sites. However, OCP levels showed tissue and sex dependence. Boosted regression trees (BRTs) and partial least squares structural equation models (PLS-SEMs) were built to better investigate the main factors affecting the bioaccumulation of OCPs. Lipid content, negatively correlated with OCP levels, was the main factor. In vitro silicon modeling indicated that CYP3A4 metabolism capacity in krill contributed to the OCP residues except for endosulfan I. The results of this study expand current knowledge of OCPs in Antarctic marine biota, as well as their influencing factors and potential mechanisms.
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Affiliation(s)
- Jingqian Xie
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China; Center for Polar Research, Shanghai Ocean University, Shanghai 201306, China; State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Ling Tao
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China
| | - Qiang Wu
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China
| | - Zhihe Bian
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China
| | - Mengqiu Wang
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China
| | - Yingming Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Guoping Zhu
- Center for Polar Research, Shanghai Ocean University, Shanghai 201306, China; College of Marine Science, Shanghai Ocean University, Shanghai 201306, China; National Engineering Research Center for Oceanic Fisheries, Shanghai 201306, China; Polar Marine Ecosystem Group, Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources, Shanghai Ocean University, Ministry of Education, Shanghai 201306, China.
| | - Tian Lin
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China
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22
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Wang Y, Ma L, He J, He Z, Wang M, Liu Z, Li Z, Wang L, Weng S, Guo C, He J. Environmental risk characteristics of bacterial antibiotic resistome in Antarctic krill. Ecotoxicol Environ Saf 2022; 232:113289. [PMID: 35144128 DOI: 10.1016/j.ecoenv.2022.113289] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 02/02/2022] [Accepted: 02/04/2022] [Indexed: 06/14/2023]
Abstract
Antibiotic resistance genes (ARGs) are ubiquitous in nature, especially in the current era of antibiotic abuse, and their existence is a global concern. In the present study, we discovered that Antarctic krill-related culturable bacteria are resistant to β-lactam, tetracyclines, aminoglycosides, and sulphamethoxazole/trimethoprim based on the antibiotic efflux mechanism. In addition, the co-occurrence of ARGs with insertion sequence (IS) (tnpA, IS91) and Intl1 on the isolates and the phylogenetic analysis results of the whole-genome revealed low-frequency ARG transfer events, implying the transferability of these ARGs. These findings provide an early warning for the wide assessment of Antarctic microbiota in the spread of ARGs. Our work provides novel insights into understanding ARGs in culturable host-associated microorganisms, and their ecological risks and has important implications for future risk assessments of antibiotic resistance in extreme environments.
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Affiliation(s)
- Yuanyuan Wang
- State Key Laboratory for Biocontrol, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Marine, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China
| | - Lingbo Ma
- Key Laboratory of the East China Sea and Oceanic Fishery Resources Exploitation, Ministry of Agriculture, East China Sea Fisheries Research Institute, Shanghai 116023, PR China
| | - Jian He
- State Key Laboratory for Biocontrol, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Marine, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China
| | - Zhili He
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China
| | - Muhua Wang
- State Key Laboratory for Biocontrol, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Marine, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China
| | - Zixuan Liu
- State Key Laboratory for Biocontrol, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Marine, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China
| | - Zhimin Li
- State Key Laboratory for Biocontrol, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Marine, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China
| | - Lumin Wang
- Key Laboratory of the East China Sea and Oceanic Fishery Resources Exploitation, Ministry of Agriculture, East China Sea Fisheries Research Institute, Shanghai 116023, PR China
| | - Shaoping Weng
- Guangdong Provincial Key Laboratory of Marine Resources, and Coastal Engineering and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China
| | - Changjun Guo
- State Key Laboratory for Biocontrol, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Marine, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Marine Resources, and Coastal Engineering and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China.
| | - Jianguo He
- State Key Laboratory for Biocontrol, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Marine, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Marine Resources, and Coastal Engineering and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China.
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23
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Sun N, Hu S, Wang D, Jiang P, Zhang S, Lin S. Calcium Delivery Systems Assembled using Antarctic Krill Derived Heptapeptides: Exploration of the Assembly Mechanism, In Vitro Digestion Profile, and Calcium Absorption Behavior. J Agric Food Chem 2022; 70:2018-2028. [PMID: 35107281 DOI: 10.1021/acs.jafc.1c06951] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
A novel heptapeptide QEELISK derived from Antarctic krill was used to assemble a calcium delivery system, of which the calcium binding mechanism of QEELISK, in vitro digestion kinetics, and calcium absorption behaviors were explored. QEELISK with continuous Glu possessed higher calcium binding capacity than that of QELEISK and QAALISK. Ca2+ bound to the carboxyl oxygen of Glu at position 3 of the QEELISK peptide at a stoichiometric ratio of 1:1 through charge-charge interaction; the formed QEELISK-Ca showed superior stability. Moreover, QEELISK-Ca underwent disaggregation and self-assembly during in vitro digestion reflected by visualization of calcium ions and circular dichroism spectra. QELEISK was partially stable during gastrointestinal digestion, and calcium chelation improved the digestive stability of QELEISK. In addition, a significant enhancement of calcium absorption with QELEISK-Ca occurred in the duodenum and ileum when compared to CaCl2 absorption, which indicated that QEELISK might carry calcium ions through the gastrointestinal tract.
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Affiliation(s)
- Na Sun
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, P. R. China
- Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian 116034, P. R. China
| | - Shengjie Hu
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, P. R. China
| | - Di Wang
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, P. R. China
| | - Pengfei Jiang
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, P. R. China
- Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian 116034, P. R. China
| | - Simin Zhang
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, P. R. China
- Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian 116034, P. R. China
| | - Songyi Lin
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, P. R. China
- Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian 116034, P. R. China
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24
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Kehrig HA, Hauser-Davis RA, Muelbert MMC, Almeida MG, Di Beneditto APM, Rezende CE. Mercury and stable carbon and nitrogen isotopes in the natal Fur of two Antarctic pinniped species. Chemosphere 2022; 288:132500. [PMID: 34656627 DOI: 10.1016/j.chemosphere.2021.132500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 10/04/2021] [Accepted: 10/05/2021] [Indexed: 06/13/2023]
Abstract
Southern elephant seal (SES) and Antarctic fur seal (AFS) are short Southern Ocean food web top predators and are spatial and temporal trend bioindicators of Antarctic Hg bioavailability. Hg, stable isotope composition (δ13C and δ15N) and trophic position (TP) regarding sex were determined using lanugo samples from Antarctic pinnipeds pups (SES n = 35 and AFS n = 11). Hg concentrations in over 50% of the SES pups (mean 5.9 ± 3.1 mg kg-1 dry wt.) are compatible with those found to cause neurologic damage to polar bears in the Arctic. No significant differences regarding sexes for SES or AFS are found based on mean Hg concentrations normalized by body weight. δ15N values and TPs are similar among both species, indicating that gestating SES and AFS mothers feed at the same trophic level. Significantly different δ13C values were found, indicating distinct feeding grounds for mothers belonging to both species when pup lanugo is formed in utero; while SES females like to feed in Antarctic waters, AFS females remain in sub-Antarctic waters. The differences in Hg and δ13C observed for both species reflect not only contrasting feeding habits and anthropogenic Hg inputs, but also maternal foraging strategies.
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Affiliation(s)
- Helena A Kehrig
- Universidade Estadual do Norte Fluminense Darcy Ribeiro, Laboratório de Ciências Ambientais, 28013-602, Campos dos Goytacazes, RJ, Brazil.
| | - Rachel Ann Hauser-Davis
- Laboratório de Avaliação e Promoção da Saúde Ambiental, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Av. Brasil, 4.365, Manguinhos, Rio de Janeiro, 21040-360, Brazil
| | - Monica M C Muelbert
- Instituto do Mar, Universidade Federal de São Paulo, Rua Carvalho de Mendonça 144, Santos, São Paulo, 11070-100, Brazil
| | - Marcelo G Almeida
- Universidade Estadual do Norte Fluminense Darcy Ribeiro, Laboratório de Ciências Ambientais, 28013-602, Campos dos Goytacazes, RJ, Brazil
| | - Ana Paula M Di Beneditto
- Universidade Estadual do Norte Fluminense Darcy Ribeiro, Laboratório de Ciências Ambientais, 28013-602, Campos dos Goytacazes, RJ, Brazil
| | - Carlos E Rezende
- Universidade Estadual do Norte Fluminense Darcy Ribeiro, Laboratório de Ciências Ambientais, 28013-602, Campos dos Goytacazes, RJ, Brazil
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25
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Atkinson A, Hill SL, Reiss CS, Pakhomov EA, Beaugrand G, Tarling GA, Yang G, Steinberg DK, Schmidt K, Edwards M, Rombolá E, Perry FA. Stepping stones towards Antarctica: Switch to southern spawning grounds explains an abrupt range shift in krill. Glob Chang Biol 2022; 28:1359-1375. [PMID: 34921477 DOI: 10.1111/gcb.16009] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 08/25/2021] [Accepted: 11/05/2021] [Indexed: 06/14/2023]
Abstract
Poleward range shifts are a global-scale response to warming, but these vary greatly among taxa and are hard to predict for individual species, localized regions or over shorter (years to decadal) timescales. Moving poleward might be easier in the Arctic than in the Southern Ocean, where evidence for range shifts is sparse and contradictory. Here, we compiled a database of larval Antarctic krill, Euphausia superba and, together with an adult database, it showed how their range shift is out of step with the pace of warming. During a 70-year period of rapid warming (1920s-1990s), distribution centres of both larvae and adults in the SW Atlantic sector remained fixed, despite warming by 0.5-1.0°C and losing sea ice. This was followed by a hiatus in surface warming and ice loss, yet during this period the distributions of krill life stages shifted greatly, by ~1000 km, to the south-west. Understanding the mechanism of such step changes is essential, since they herald system reorganizations that are hard to predict with current modelling approaches. We propose that the abrupt shift was driven by climatic controls acting on localized recruitment hotspots, superimposed on thermal niche conservatism. During the warming hiatus, the Southern Annular Mode index continued to become increasingly positive and, likely through reduced feeding success for larvae, this led to a precipitous decline in recruitment from the main reproduction hotspot along the southern Scotia Arc. This cut replenishment to the northern portion of the krill stock, as evidenced by declining density and swarm frequency. Concomitantly, a new, southern reproduction area developed after the 1990s, reinforcing the range shift despite the lack of surface warming. New spawning hotspots may provide the stepping stones needed for range shifts into polar regions, so planning of climate-ready marine protected areas should include these key areas of future habitat.
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Affiliation(s)
| | | | - Christian S Reiss
- South West Fisheries Science Centre, NOAA Fisheries, La Jolla, California, USA
| | - Evgeny A Pakhomov
- Department of Earth, Ocean and Atmospheric Sciences and Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, British Columbia, Canada
- Hakai Institute, Heriot Bay, British Columbia, Canada
| | - Gregory Beaugrand
- Laboratoire d'Océanologie et de Géosciences, UMR 8187 LOG, Centre National de la Recherche Scientifique, Station Marine de Wimereux, Université de Lille, Université du Littoral Côte d'Opale, Wimereux, France
| | | | - Guang Yang
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Deborah K Steinberg
- Virginia Institute of Marine Science, College of William & Mary, Gloucester Point, Virginia, USA
| | - Katrin Schmidt
- School of Geography, Earth and Environmental Sciences, University of Plymouth, Plymouth, UK
| | | | - Emilce Rombolá
- Instituto Antártico Argentino, Dirección Nacional del Antártico, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Cientifcas y Técnicas, Buenos Aires, Argentina
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26
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Ye H, Zhao L, Ren X, Cai Y, Chi H. "Switch-Off-On" Detection of Fe 3+ and F - Ions Based on Fluorescence Silicon Nanoparticles and Their Application to Food Samples. Nanomaterials (Basel) 2022; 12:nano12020213. [PMID: 35055232 PMCID: PMC8779261 DOI: 10.3390/nano12020213] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 12/27/2021] [Accepted: 01/07/2022] [Indexed: 02/05/2023]
Abstract
An approach to the detection of F− ions in food samples was developed based on a “switch-off-on” fluorescence probe of silicon nanoparticles (SiNPs). The fluorescence of the synthetic SiNPs was gradually quenched in the presence of Fe3+ ion and slightly recovered with the addition of F− ion owing to the formation of a stable and colorless ferric fluoride. The fluorescence recovery exhibited a good linear relationship (R2 = 0.9992) as the concentration of F− ion increased from 0 to 100 μmol·L−1. The detection limit of the established method of F− ion was 0.05 μmol·L−1. The recovery experiments confirmed the accuracy and reliability of the proposed method. The ultraviolet–visible spectra, fluorescence decays, and zeta potentials evidenced the fluorescence quenching mechanism involving the electron transfer between the SiNPs and Fe3+ ion, while the fluorescence recovery resulted from the formation of ferric fluoride. Finally, SiNPs were successfully applied to detect F− ions in tap water, Antarctic krill, and Antarctic krill powder.
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Affiliation(s)
- Hongli Ye
- Laboratory of Aquatic Product Quality, Safety and Processing, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China; (H.Y.); (Y.C.)
- Key Laboratory of Control of Safety and Quality for Aquatic Product, Ministry of Agriculture and Rural Affairs, Beijing 100141, China
| | - Lukai Zhao
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China;
| | - Xinghui Ren
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Sciences, College of Chemistry, Nankai University, Tianjin 300071, China;
| | - Youqiong Cai
- Laboratory of Aquatic Product Quality, Safety and Processing, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China; (H.Y.); (Y.C.)
- Key Laboratory of Control of Safety and Quality for Aquatic Product, Ministry of Agriculture and Rural Affairs, Beijing 100141, China
| | - Hai Chi
- Laboratory of Aquatic Product Quality, Safety and Processing, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China; (H.Y.); (Y.C.)
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China;
- Correspondence:
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27
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Reproductive traits of common Euphausids in the south of Antarctic Polar Front. Ying Yong Sheng Tai Xue Bao 2021; 32:4156-64. [PMID: 34898132 DOI: 10.13287/j.1001-9332.202111.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Euphausiids (krill) is a basic component of the Southern Ocean ecosystem, with a key role in the Antarctic marine food web. Krill may be the largest unexploited animal protein source for human beings. There is a great deal of interest in exploiting krill resources. Our understanding is poor about the biology of those species, particularly the reproductive traits of krill species, expect for Euphausia superba. Here, we reviewed related studies and revealed that different species of krill undergo similar physiological steps during ovary development. There are regional variations in the size of krill oocytes. The sexual maturity stages of female krill could be classified by observing the thelycum and ovarian morphology. There are latitudinal variations in spawning periods among species and regional variations within species. Most observations showed that krill samples are dominated by females. Future research should be conducted, i.e., (1) strengthening the study on the reproductive traits of krill, besides Euphausia superba, and further to explore the effects of seasonal and regional reproductive traits on the distribution of krill around Antarctica, (2) focusing on experimental biology in order to clarify the mechanism of spawning times of krill and further to calculate accurately the fecundity to evaluate the impacts of exploiting krill resource.
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28
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Wang Y, Ma L, He J, Liu Z, Weng S, Wang L, He J, Guo C. Whole genome sequencing and comparative genomic analyses of Planococcus alpniumensis MSAK28401 T, a new species isolated from Antarctic krill. BMC Microbiol 2021; 21:288. [PMID: 34686131 PMCID: PMC8532331 DOI: 10.1186/s12866-021-02347-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 10/06/2021] [Indexed: 11/12/2022] Open
Abstract
Background Extremophiles have attracted much attention in the last few decades, as they possess different properties by producing certain useful metabolites. However, the secondary metabolism of the extremophiles of Antarctic krill has received little attention. Results In this study, a new bacterial strain MSAK28401T from Antarctic krill was isolated and identified. The results of analysis on phenotypic, chemotaxonomic, and genomic characteristics showed that the strain MSAK28401T belongs to the genus Planococcus. Cells of this strain were coccoid (0.89–1.05 μm) and aerobic. The majority of the fatty acid content was C15:0 anteiso (37.67 ± 0.90%) followed by C16:1 ω7c alcohol (10.37 ± 1.22%) and C16:0 iso (9.36 ± 0.71%). The calculated average nucleotide identity and DNA–DNA hybridization values between the strain MSAK28401T and type strains P. citreus DSM 20549T and P. rifietoensis M8T were lower than 91 and 70%, respectively. The strain MSAK28401T (=KCTC 43283T and MCCC 1k05448T) represented a new member of the genus Planococcus and was named P. alpniumensis sp. nov. Moreover, genes involved in the degradation of aromatic compounds (e.g., salicylate, gentisate, and quinate) were found in the genome, implying that strain MSAK28401T has an aromatic compound as its potential metabolite. This work will help us understand the genomic characteristics and potential metabolic pathway of Planococcus from Antarctic krill. Conclusions This study reported the genomic information and phenotypic characteristics of the new strain P. alpniumensis MSAK28401T isolated from Antarctic krill, and provided the genome information of Planococcus strains for further studying the function roles in aromatic compound metabolism. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-021-02347-3.
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Affiliation(s)
- Yuanyuan Wang
- State Key Laboratory for Biocontrol / Southern Laboratory of Ocean Science and Engineering (Guangdong, Zhuhai), School of Marine Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou, 510275, People's Republic of China
| | - Lingbo Ma
- Key Laboratory of the East China Sea and Oceanic Fishery Resources Exploitation, Ministry of Agriculture, East China Sea Fisheries Research Institute, Shanghai, 116023, People's Republic of China
| | - Jian He
- State Key Laboratory for Biocontrol / Southern Laboratory of Ocean Science and Engineering (Guangdong, Zhuhai), School of Marine Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou, 510275, People's Republic of China
| | - Zixuan Liu
- State Key Laboratory for Biocontrol / Southern Laboratory of Ocean Science and Engineering (Guangdong, Zhuhai), School of Marine Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou, 510275, People's Republic of China
| | - Shaoping Weng
- Guangdong Province Key Laboratory for Aquatic Economic Animals, and Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Sun Yat-sen University, 135 Xingang Road West, Guangzhou, 510275, People's Republic of China
| | - Lumin Wang
- Key Laboratory of the East China Sea and Oceanic Fishery Resources Exploitation, Ministry of Agriculture, East China Sea Fisheries Research Institute, Shanghai, 116023, People's Republic of China
| | - Jianguo He
- State Key Laboratory for Biocontrol / Southern Laboratory of Ocean Science and Engineering (Guangdong, Zhuhai), School of Marine Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou, 510275, People's Republic of China.,Guangdong Province Key Laboratory for Aquatic Economic Animals, and Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Sun Yat-sen University, 135 Xingang Road West, Guangzhou, 510275, People's Republic of China
| | - Changjun Guo
- State Key Laboratory for Biocontrol / Southern Laboratory of Ocean Science and Engineering (Guangdong, Zhuhai), School of Marine Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou, 510275, People's Republic of China. .,Guangdong Province Key Laboratory for Aquatic Economic Animals, and Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Sun Yat-sen University, 135 Xingang Road West, Guangzhou, 510275, People's Republic of China.
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Zeb L, Teng X, Shafiq M, Wang S, Xiu Z, Su Z. Three-liquid-phase salting-out extraction of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)-rich oils from Euphausia superba. Eng Life Sci 2021; 21:666-682. [PMID: 34690637 PMCID: PMC8518559 DOI: 10.1002/elsc.202000098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/20/2021] [Accepted: 07/14/2021] [Indexed: 11/06/2022] Open
Abstract
The TLPSOES parameters were optimized by response surface methodology using Box-Behnken design, which were 16.5% w/w of ammonium citrate, 17.5% w/w of ethanol, and 46% w/w of n-hexane at 70 min of stirring time. Under optimized conditions the extraction efficiency attained was 90.91 ± 0.97% of EPA, 90.02 ± 1.04% of DHA, and 91.85 ± 1.11% of KO in the top n-hexane phase. The highest extraction efficiency of proteins and flavonoids, i.e. 88.34 ± 1.35% and 79.67 ± 1.13%, was recorded in the solid interface and ethanol phase, respectively. The KO extracted by TLPSOES system consisted of lowest fluoride level compared to the conventional method and whole wet krill biomass. The TLPSOES is a potential candidate for nutraceutical industry of KO extraction from wet krill biomass.
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Affiliation(s)
- Liaqat Zeb
- School of BioengineeringDalian University of TechnologyDalianP. R. China
| | - Xin‐Nan Teng
- School of BioengineeringDalian University of TechnologyDalianP. R. China
| | - Muhammad Shafiq
- School of BioengineeringDalian University of TechnologyDalianP. R. China
| | - Shu‐Chang Wang
- School of BioengineeringDalian University of TechnologyDalianP. R. China
| | - Zhi‐Long Xiu
- School of BioengineeringDalian University of TechnologyDalianP. R. China
| | - Zhi‐Guo Su
- State Key Laboratory of Biochemical EngineeringInstitute of Process EngineeringChinese Academy of SciencesBeijingP. R. China
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30
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Prado-Cabrero A, Nolan JM. Omega-3 nutraceuticals, climate change and threats to the environment: The cases of Antarctic krill and Calanus finmarchicus. Ambio 2021; 50:1184-1199. [PMID: 33502683 PMCID: PMC8068752 DOI: 10.1007/s13280-020-01472-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 11/20/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
The nutraceutical market for EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) is promoting fishing for Euphasia superba (Antarctic krill) in the Southern Ocean and Calanus finmarchicus in Norwegian waters. This industry argues that these species are underexploited, but they are essential in their ecosystems, and climate change is altering their geographical distribution. In this perspective, we advocate the cessation of fishing for these species to produce nutraceuticals with EPA and DHA. We argue that this is possible because, contrary to what this industry promotes, the benefits of these fatty acids only seem significant to specific population groups, and not for the general population. Next, we explain that this is desirable because there is evidence that these fisheries may interact with the impact of climate change. Greener sources of EPA and DHA are already available on the market, and their reasonable use would ease pressure on the Arctic and Antarctic ecosystems.
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Affiliation(s)
- Alfonso Prado-Cabrero
- Nutrition Research Centre Ireland, School of Health Science, Carriganore House, Waterford Institute of Technology, West Campus, Carriganore, Waterford, Ireland
| | - John M. Nolan
- Nutrition Research Centre Ireland, School of Health Science, Carriganore House, Waterford Institute of Technology, West Campus, Carriganore, Waterford, Ireland
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Michael K, Suberg LA, Wessels W, Kawaguchi S, Meyer B. Facing Southern Ocean warming: Temperature effects on whole animal performance of Antarctic krill (Euphausia superba). ZOOLOGY 2021; 146:125910. [PMID: 33735797 DOI: 10.1016/j.zool.2021.125910] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 02/19/2021] [Accepted: 02/23/2021] [Indexed: 10/22/2022]
Abstract
The ongoing environmental changes in the Southern Ocean may cause a dramatic decrease in habitat quality. Due to its central position in the food web, Antarctic krill (Euphausia superba) is a key species of the marine Antarctic ecosystem. It is therefore crucial to understand how increasing water temperatures affect important krill life-cycle processes. Here, a long-term (August - March) laboratory acclimation experiment at different temperature scenarios (0.5 °C, 1.5 °C, 2.5 °C, 3.5 °C, 5 °C, 7 °C) was performed and the effects of elevated temperatures on whole animal parameters (O2 consumption, body length, length of the digestive gland) were analyzed. The response of krill oxygen consumption to different experimental temperatures differed between acute/short-term and long-term acclimation. After 8 months, krill oxygen consumption remained unchanged up to temperatures of 3.5 °C and was significantly higher at temperatures > 3.5 °C. Krill acclimated to temperatures ≥ 3.5 °C were significantly smaller at the end of the experiment. Limited food intake and/or conversion may have contributed to this effect, especially pronounced after the onset of the reproductive period. In addition, the seasonal growth pattern in males differed from that of females. Together, our findings indicate that warming Southern Ocean waters are likely to increase metabolic rate in krill, possibly altering the amount of energy available for other important life-cycle processes, a finding directly related to future population dynamics and fisheries management.
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Affiliation(s)
- Katharina Michael
- Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26111, Oldenburg, Germany.
| | - Lavinia A Suberg
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Scientific Division Polar Biological Oceanography, Am Handelshafen 12, 27570, Bremerhaven, Germany
| | - Wiebke Wessels
- Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26111, Oldenburg, Germany
| | - So Kawaguchi
- Australian Antarctic Division, Department of Agriculture, Water and the Environment, 203 Channel Highway, Kingston, Tasmania, 7050, Australia; Antarctic Climate and Ecosystems Cooperative Research Centre, 20 Castray Esplanade, Hobart, Tasmania, 7000, Australia
| | - Bettina Meyer
- Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26111, Oldenburg, Germany; Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Scientific Division Polar Biological Oceanography, Am Handelshafen 12, 27570, Bremerhaven, Germany; Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg (HIFMB), Ammerländer Heerstraße 231, 26129, Oldenburg, Germany
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32
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Bergami E, Manno C, Cappello S, Vannuccini ML, Corsi I. Nanoplastics affect moulting and faecal pellet sinking in Antarctic krill (Euphausia superba) juveniles. Environ Int 2020; 143:105999. [PMID: 32763632 DOI: 10.1016/j.envint.2020.105999] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 07/17/2020] [Accepted: 07/17/2020] [Indexed: 06/11/2023]
Abstract
Plastic debris has been identified as a potential threat to Antarctic marine ecosystems, however, the impact of nanoplastics (<1 μm) is currently unexplored. Antarctic krill (Euphausia superba) is a keystone species of Southern Ocean pelagic ecosystems, which plays a central role in the Antarctic food webs and carbon (C) cycle. Krill has been shown to rapidly fragment microplastic beads through the digestive system, releasing nanoplastics with unknown toxicological effects. Here we exposed krill juveniles to carboxylic (COOH, anionic) and amino- (NH2, cationic) polystyrene nanoparticles (PS NPs) and we investigated lethal and sub-lethal endpoints after 48 h. The analysis of PS NP suspensions in Antarctic sea water (SW) media showed that PS-COOH formed large agglomerates (1043 ± 121 nm), while PS-NH2 kept their nominal size (56.8 ± 3 nm) during the exposure time. After 48 h, no mortality was found but increase in exuviae production (12.6 ± 1.3%) and reduced swimming activity were observed in juveniles exposed to PS-NH2. The microbial community composition in SW supports the release of krill moults upon PS NP exposure and stimulates further research on the pivotal role of krill in shaping Southern Ocean bacterial assemblages. The presence of fluorescent signal in krill faecal pellets (FPs) confirmed the waterborne ingestion and egestion of PS-COOH at 48 h of exposure. Changes in FP structure and properties were also associated to the incorporation of PS NPs regardless of their surface charge. The effects of PS NPs on krill FP properties were compared to Control 0 h as a reference for full FPs (plastic vs food) and Control 48 h as a reference for more empty-like FPs (plastic vs lack of food). Exposure to PS NPs led to a FP sinking rate comparable to Control 48 h, but significantly lower than Control 0 h (58.40 ± 23.60 m/d and 51.23 ± 28.60 m/d for PS-COOH and PS-NH2; 168.80 ± 74.58 m/d for Control 0 h). Considering the important role played by krill in the food web and C export in the Southern Ocean, the present study provides cues about the potential impact of nanoplastics on Antarctic pelagic ecosystems and their biogeochemical cycles.
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Affiliation(s)
- E Bergami
- Department of Physical, Earth and Environmental Sciences (DSFTA), University of Siena, Siena 53100, Italy.
| | - C Manno
- British Antarctic Survey (BAS), Natural Environment Research Council, Cambridge CB3 0ET, UK
| | - S Cappello
- Institute for Biological Resources and Marine Biotechnologies (IRBIM), National Research Council, Messina 98121, Italy
| | - M L Vannuccini
- Department of Physical, Earth and Environmental Sciences (DSFTA), University of Siena, Siena 53100, Italy
| | - I Corsi
- Department of Physical, Earth and Environmental Sciences (DSFTA), University of Siena, Siena 53100, Italy
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33
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Yuan Y, Chen L, Shi W, Wang Z, Zhang H. Insight into Physicochemical, Rheological, and Antibacterial Properties of Chitosan Extracted from Antarctic krill: A Comparative Study. Molecules 2020; 25:E4074. [PMID: 32906578 DOI: 10.3390/molecules25184074] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 08/16/2020] [Accepted: 08/21/2020] [Indexed: 11/17/2022] Open
Abstract
In this work, physicochemical, rheological, and antibacterial properties of chitosan (CS) extracted from white shrimp (WS), giant river prawn (GP), and Antarctic krill (AK) were investigated. The results demonstrated that molecular weight (MW) of commercial chitosan (CCS), WSCS, GPCS, and AKCS were 1175.8, 2130.4, 1293.3, and 1109.3 kDa with the degree of deacetylation (DDA) of 73.5, 74.1, 82.1, and 75.9%, respectively. Fourier transform infrared (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and scanning electron microscope (SEM) were employed to study the structural differences of CS. Moreover, storage modulus (G′) and loss modulus (G″) of AKCS were lower than that of WSCS and GPCS, respectively, but higher than that of CCS. Minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC) of CS against Escherichia coli and Staphylococcus aureus were investigated at concentration between 0.0125 and 1 mg/mL. These results highlighted that AKCS with low viscoelastic properties had a potential application in food and pharmaceutical application.
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34
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Liu H, Zhu GP. [Spatial-temporal variation in hotspot and coldspot of Antarctic krill distribution in recent 100 years]. Ying Yong Sheng Tai Xue Bao 2020; 31:1015-1022. [PMID: 32537999 DOI: 10.13287/j.1001-9332.202003.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
To analyze the long-term variation in the spatial-temporal patterns of Antarctic krill (Euphausia superba) distribution, based on krill density data collected from 1926 to 2016, we analyzed the spatial and temporal variation of krill using the Getis-Ord Gi* statistic and the Triangulated Irregular Network (TIN) model. We compared the krill abundance, the percentage of krill abundance, and the size of hotspot/coldspot area. The results showed that there were one core hot-spot area, one sub-hotspot area and one edge hotspot area from 1926 to 1935 and from 1936 to 1945; one core hotspot area, one sub-hotspot area and one edge hotspot/coldspot area from 1976 to 1985; two core hotspot areas, two sub-hotspot areas, two edge hotspot areas, one sub-coldspot area and one coldspot area from 1986 to 1995; two core hotspot areas, two sub-hotspot/sub-coldspot areas and two edge hotspot/coldspot areas from 1996 to 2005; and from 2006 to 2016, there were two sub-hotspot areas, two edge hotspot areas, one sub-coldspot area and one edge coldspot area, respectively. Those hotspots/coldspots mostly occurred in the South Sandwich Islands, the Antarctic Peninsula, and the west of the Prydz Bay. From 1926 to 2016, krill abundance, the percentage of krill abundance in the hotspot area and the size of hotspot area had generally reduced, but the percentage of krill abundance in coldspot area and the size of coldspot area were increasing, while krill abundance in coldspot area decreased. It is a feasible approach to build an irregular triangle network to measure the size of hotspot/coldspot area and utilize hotspot analysis with 95% confidence to analyze the spatial-temporal pattern of krill distribution.
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Affiliation(s)
- Hui Liu
- College of Marine Sciences, Shanghai Ocean University, Shanghai 201306, China.,Center for Polar Research, Shanghai Ocean University, Shanghai 201306, China.,Polar Marine Ecosystem Laboratory, Ministry of Education Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources, Shanghai Ocean University, Shanghai 201306, China
| | - Guo-Ping Zhu
- College of Marine Sciences, Shanghai Ocean University, Shanghai 201306, China.,Center for Polar Research, Shanghai Ocean University, Shanghai 201306, China.,Polar Marine Ecosystem Laboratory, Ministry of Education Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources, Shanghai Ocean University, Shanghai 201306, China.,National Engineering Research Center for Oceanic Fisheries, Shanghai 201306, China
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35
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Liu B, Pan S. Effect of chitosan coatings incorporated sodium phytate on the shelf-life of Antarctic krill (Euphausia superba). Int J Biol Macromol 2020; 151:62-65. [PMID: 32068063 DOI: 10.1016/j.ijbiomac.2020.02.148] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/07/2020] [Accepted: 02/14/2020] [Indexed: 11/19/2022]
Abstract
Chitosan is a preservative with potent antibacterial activity, and sodium phytate has antioxidant activity and potent ion chelating ability. The present work aimed to explore the effects of chitosan coating combined with sodium phytate (0.1% sodium phytate + 1% chitosan) on preserving Antarctic krill (Euphausia superba) during partially frozen storage. Treatment of chitosan coating combined with sodium phytate significantly suppressed microbial growth, the increases in pH value, total volatile basic nitrogen and sensory deterioration of Antarctic krill (E. superba) during partially frozen storage. Therefore, chitosan coating combined with sodium phytate may be a practical method to suppress quality deterioration of Antarctic krill and thus extend its shelf life.
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Affiliation(s)
- Bing Liu
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, 59 Cangwu Road, Haizhou 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, 59 Cangwu Road, Haizhou 222005, China; Jiangsu Key Laboratory of Marine Biotechnology, 59 Cangwu Road, Haizhou 222005, China
| | - Saikun Pan
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, 59 Cangwu Road, Haizhou 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, 59 Cangwu Road, Haizhou 222005, China; Jiangsu Key Laboratory of Marine Biotechnology, 59 Cangwu Road, Haizhou 222005, China.
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Gao R, Chen L, Zhang W, Zhang S, Rao J, Hu J. Effect of dietary Antarctic krill Euphausia superba on the growth performance and nonspecific immunity of red swamp crayfish Procambarus clarkia. Fish Shellfish Immunol 2020; 96:122-125. [PMID: 31805411 DOI: 10.1016/j.fsi.2019.12.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 11/28/2019] [Accepted: 12/01/2019] [Indexed: 06/10/2023]
Abstract
This study aims to investigate the effects of replacing different proportions of fishmeal with Antarctic krill (AK) on the growth performance, body composition and nonspecific immunity index of red swamp crayfish Procambarus clarkia. AK was used to replace 0 (control), 25%, 50% and 100% of the fishmeal in the basic diet of crayfish to formulate four test feeds with basically equivalent nitrogen and lipid contents; these feeds were denoted AK0, AK25, AK50 and AK100, respectively. Compared with the control group, crayfish fed diets with AK replacement showed increased body weight gain; feed efficiency; survival rate; body protein content; phenoloxidase, superoxide dismutase and glutathione peroxidase activities; total haemocyte counts; number of hyaline, semigranular and granular cells; and disease resistance against Aeromonas hydrophila. Conversely, the body lipid level of these crayfish decreased relative to that of the control. However, a high AK level (AK100) does not show improvements in efficiency compared with a moderate AK level (AK50). Based on the efficiency of AK in enhancing the growth performance and nonspecific immunity of crayfish, the optimum replacement proportion of fishmeal with AK was 50%. These results confirm that AK can promote the growth of crayfish and improve their disease resistance.
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Affiliation(s)
- Renjiao Gao
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, 59 Cangwu Road, Haizhou, Lianyungang, 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, 59 Cangwu Road, Haizhou, Lianyungang, 222005, China; College of Marine Life and Fisheries, Jiangsu Ocean University, 59 Cangwu Road, Haizhou, Lianyungang, 222005, China
| | - Li Chen
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, 59 Cangwu Road, Haizhou, Lianyungang, 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, 59 Cangwu Road, Haizhou, Lianyungang, 222005, China; College of Marine Life and Fisheries, Jiangsu Ocean University, 59 Cangwu Road, Haizhou, Lianyungang, 222005, China.
| | - Wei Zhang
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, 59 Cangwu Road, Haizhou, Lianyungang, 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, 59 Cangwu Road, Haizhou, Lianyungang, 222005, China; College of Marine Life and Fisheries, Jiangsu Ocean University, 59 Cangwu Road, Haizhou, Lianyungang, 222005, China
| | - Shuo Zhang
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, 59 Cangwu Road, Haizhou, Lianyungang, 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, 59 Cangwu Road, Haizhou, Lianyungang, 222005, China; College of Marine Life and Fisheries, Jiangsu Ocean University, 59 Cangwu Road, Haizhou, Lianyungang, 222005, China
| | - Jie Rao
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, 59 Cangwu Road, Haizhou, Lianyungang, 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, 59 Cangwu Road, Haizhou, Lianyungang, 222005, China; College of Marine Life and Fisheries, Jiangsu Ocean University, 59 Cangwu Road, Haizhou, Lianyungang, 222005, China
| | - Jun Hu
- Jiangsu Haierzi Biological Technology Co. Ltd., 9 Bofu Road, Liuhe, Nanjin, 215000, China
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Mödinger Y, Schön C, Wilhelm M, Hals PA. Plasma Kinetics of Choline and Choline Metabolites After A Single Dose of Superba BoostTM Krill Oil or Choline Bitartrate in Healthy Volunteers. Nutrients 2019; 11:nu11102548. [PMID: 31652561 PMCID: PMC6835836 DOI: 10.3390/nu11102548] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 10/16/2019] [Accepted: 10/18/2019] [Indexed: 12/23/2022] Open
Abstract
As an essential nutrient, the organic water-soluble compound choline is important for human health. Choline is required for numerous biological processes, including the synthesis of neurotransmitters, and it is an important prerequisite for structural integrity and the functioning of cells. A choline-rich diet provides crucial choline sources, yet additional choline dietary supplements might be needed to fully meet the body’s requirements. Dependent on the structure of choline in different sources, absorption and metabolism may differ and strongly impact the bioavailability of circulating choline. This study in healthy volunteers aimed to compare the pharmacokinetics of free choline and of selected choline metabolites between the single dose intake of phosphatidylcholine, present in SuperbaBoostTM krill oil, and choline bitartrate salt. Results demonstrate that albeit free choline levels in plasma were comparable between both choline sources, peak choline concentration was reached significantly later upon intake of SuperbaBoostTM. Moreover, the occurrence of choline metabolites differed between the study products. Levels of the biologically important metabolites betaine and dimethylglycine (DMG) were higher, while levels of trimethylamine N-oxide (TMAO) were substantially lower upon intake of SuperbaBoostTM compared to choline bitartrate.
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Affiliation(s)
- Yvonne Mödinger
- BioTeSys GmbH, Schelztorstraße 54-56, 73728 Esslingen, Germany.
| | | | - Manfred Wilhelm
- Department of Mathematics, Natural and Economic Sciences, Ulm University of Applied Sciences, Albert-Einstein-Allee 55, 89081 Ulm, Germany.
| | - Petter-Arnt Hals
- Aker BioMarine Antarctic AS, Oksenøyveien 10, 1327 Lysaker, Norway.
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Zerbini AN, Adams G, Best J, Clapham PJ, Jackson JA, Punt AE. Assessing the recovery of an Antarctic predator from historical exploitation. R Soc Open Sci 2019; 6:190368. [PMID: 31824687 PMCID: PMC6837233 DOI: 10.1098/rsos.190368] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 09/23/2019] [Indexed: 06/01/2023]
Abstract
The recovery of whale populations from centuries of exploitation will have important management and ecological implications due to greater exposure to anthropogenic activities and increasing prey consumption. Here, a Bayesian population model integrates catch data, estimates of abundance, and information on genetics and biology to assess the recovery of western South Atlantic (WSA) humpback whales (Megaptera novaeangliae). Modelling scenarios evaluated the sensitivity of model outputs resulting from the use of different data, different model assumptions and uncertainty in catch allocation and in accounting for whales killed but not landed. A long period of exploitation drove WSA humpback whales to the brink of extinction. They declined from nearly 27 000 (95% PI = 22 800-33 000) individuals in 1830 to only 450 (95% PI = 200-1400) whales in the mid-1950s. Protection led to a strong recovery and the current population is estimated to be at 93% (95% PI = 73-100%) of its pre-exploitation size. The recovery of WSA humpback whales may result in large removals of their primary prey, the Antarctic krill (Euphausia superba), and has the potential to modify the community structure in their feeding grounds. Continued monitoring is needed to understand how these whales will respond to modern threats and to climate-driven changes to their habitats.
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Affiliation(s)
- Alexandre N. Zerbini
- Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 7600 Sand Point Way NE, Seattle, WA 98115-6349, USA
- Marine Ecology and Telemetry Research, 2468 Camp McKenzie Tr NW, Seabeck, WA 98380, USA
- Cascadia Research Collective, 218 ½ 4th Avenue W, Olympia, WA 98501, USA
- Instituto Aqualie, Avenida Doutor Paulo Japiassú Coelho 714, Sala 202, Juiz de Fora, MG, Brazil
| | - Grant Adams
- School of Aquatic and Fishery Sciences, University of Washington, 1122 NE Boat Street, Seattle, WA 98105, USA
| | - John Best
- Quantitative Ecology and Resource Management, University of Washington, 1503 NE Boat Street, Seattle, WA 98105, USA
| | | | | | - Andre E. Punt
- School of Aquatic and Fishery Sciences, University of Washington, 1122 NE Boat Street, Seattle, WA 98105, USA
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Havermans C, Auel H, Hagen W, Held C, Ensor NS, A Tarling G. Predatory zooplankton on the move: Themisto amphipods in high-latitude marine pelagic food webs. Adv Mar Biol 2019; 82:51-92. [PMID: 31229150 DOI: 10.1016/bs.amb.2019.02.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Hyperiid amphipods are predatory pelagic crustaceans that are particularly prevalent in high-latitude oceans. Many species are likely to have co-evolved with soft-bodied zooplankton groups such as salps and medusae, using them as substrate, for food, shelter or reproduction. Compared to other pelagic groups, such as fish, euphausiids and soft-bodied zooplankton, hyperiid amphipods are poorly studied especially in terms of their distribution and ecology. Hyperiids of the genus Themisto, comprising seven distinct species, are key players in temperate and cold-water pelagic ecosystems where they reach enormous levels of biomass. In these areas, they are important components of marine food webs, and they are major prey for many commercially important fish and squid stocks. In northern parts of the Southern Ocean, Themisto are so prevalent that they are considered to take on the role that Antarctic krill play further south. Nevertheless, although they are around the same size as krill, and may also occur in swarms, their feeding behaviour and mode of reproduction are completely different, hence their respective impacts on ecosystem structure differ. Themisto are major predators of meso- and macrozooplankton in several major oceanic regions covering shelves to open ocean from the polar regions to the subtropics. Based on a combination of published and unpublished occurrence data, we plot out the distributions of the seven species of Themisto. Further, we consider the different predators that rely on Themisto for a large fraction of their diet, demonstrating their major importance for higher trophic levels such as fish, seabirds and mammals. For instance, T. gaudichaudii in the Southern Ocean comprises a major part of the diets of around 80 different species of squid, fish, seabirds and marine mammals, while T. libellula in the Bering Sea and Greenland waters is a main prey item for commercially exploited fish species. We also consider the ongoing and predicted range expansions of Themisto species in light of environmental changes. In northern high latitudes, sub-Arctic Themisto species are replacing truly Arctic, ice-bound, species. In the Southern Ocean, a range expansion of T. gaudichaudii is expected as water masses warm, impacting higher trophic levels and biogeochemical cycles. We identify the many knowlegde gaps that must be filled in order to evaluate, monitor and predict the ecological shifts that will result from the changing patterns of distribution and abundance of this important pelagic group.
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Affiliation(s)
- Charlotte Havermans
- BreMarE-Bremen Marine Ecology, Marine Zoology, Universität Bremen, Bremen, Germany; Alfred-Wegener-Institut Helmholtz-Zentrum für Polar-und Meeresforschung, Bremerhaven, Germany.
| | - Holger Auel
- BreMarE-Bremen Marine Ecology, Marine Zoology, Universität Bremen, Bremen, Germany
| | - Wilhelm Hagen
- BreMarE-Bremen Marine Ecology, Marine Zoology, Universität Bremen, Bremen, Germany
| | - Christoph Held
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar-und Meeresforschung, Bremerhaven, Germany
| | - Natalie S Ensor
- British Antarctic Survey, Natural Environment Research Council, Cambridge, United Kingdom
| | - Geraint A Tarling
- British Antarctic Survey, Natural Environment Research Council, Cambridge, United Kingdom
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Clarke LJ, Suter L, King R, Bissett A, Deagle BE. Antarctic Krill Are Reservoirs for Distinct Southern Ocean Microbial Communities. Front Microbiol 2019; 9:3226. [PMID: 30697197 PMCID: PMC6340936 DOI: 10.3389/fmicb.2018.03226] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 12/11/2018] [Indexed: 11/13/2022] Open
Abstract
Host-associated bacterial communities have received limited attention in polar habitats, but are likely to represent distinct nutrient-rich niches compared to the surrounding environment. Antarctic krill (Euphausia superba) are a super-abundant species with a circumpolar distribution, and the krill microbiome may make a substantial contribution to marine bacterial diversity in the Southern Ocean. We used high-throughput sequencing of the bacterial 16S ribosomal RNA gene to characterize bacterial diversity in seawater and krill tissue samples from four locations south of the Kerguelen Plateau, one of the most productive regions in the Indian Sector of the Southern Ocean. Krill-associated bacterial communities were distinct from those of the surrounding seawater, with different communities inhabiting the moults, digestive tract and faecal pellets, including several phyla not detected in the surrounding seawater. Digestive tissues from many individuals contained a potential gut symbiont (order: Mycoplasmoidales) shown to improve survival on a low quality diet in other crustaceans. Antarctic krill swarms thus influence Southern Ocean microbial communities not only through top-down grazing of eukaryotic cells and release of nutrients into the water column, but also by transporting distinct microbial assemblages horizontally via migration and vertically via sinking faecal pellets and moulted exuviae. Changes to Antarctic krill demographics or distribution through fishing pressure or climate-induced range shifts will also influence the composition and dispersal of Southern Ocean microbial communities.
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Affiliation(s)
- Laurence J Clarke
- Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, TAS, Australia
| | - Léonie Suter
- Australian Antarctic Division, Kingston, TAS, Australia
| | - Robert King
- Australian Antarctic Division, Kingston, TAS, Australia
| | - Andrew Bissett
- Commonwealth Scientific and Industrial Research Organisation, Hobart, TAS, Australia
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Liu Y, Cong P, Li B, Song Y, Liu Y, Xu J, Xue C. Effect of thermal processing towards lipid oxidation and non-enzymatic browning reactions of Antarctic krill (Euphausia superba) meal. J Sci Food Agric 2018; 98:5257-5268. [PMID: 29652437 DOI: 10.1002/jsfa.9064] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 03/13/2018] [Accepted: 04/01/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Antarctic krill is a huge source of biomass and prospective high-quality lipid source. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), nutritionally important lipid components with poor oxidative stability, were used as markers of oxidation during thermal processing of Antarctic krill (Euphausia superba) meal by evaluating the lipolysis, lipid oxidation, and non-enzymatic browning reactions. RESULT Liquid chromatography-mass spectrometry of the phospholipids and the main oxidation products of free fatty acids and phosphatidylcholine (PC) was effective for evaluating the oxidation of EPA and DHA. During boiling, oxidation of EPA and DHA in the free fatty acid and PC fractions and hydrolysis of the fatty acids at the sn-2 position of the phospholipids were predominant. The changes in PC during drying were mainly attributed to the oxidation of EPA and DHA. Heat treatment increased the oxidation products and concentration of hydrophobic pyrrole owing to pyrrolization between phosphatidylethanolamine and the lipid oxidation products. CONCLUSION The lipid oxidation level of Antarctic krill increased after drying, owing to prolonged heating under the severe conditions. © 2018 Society of Chemical Industry.
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Affiliation(s)
- Yanzi Liu
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
| | - Peixu Cong
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
| | - Beijia Li
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
| | - Yu Song
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
| | - Yanjun Liu
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
| | - Jie Xu
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
| | - Changhu Xue
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
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Qi X, Liao E, Zhao K, Regenstein JM, Mao X. Multi-stage countercurrent process for extracting protein from Antarctic Krill ( Euphausia superba). J Food Sci Technol 2018; 55:4450-4457. [PMID: 30333641 PMCID: PMC6170336 DOI: 10.1007/s13197-018-3368-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 09/18/2017] [Accepted: 07/30/2018] [Indexed: 10/28/2022]
Abstract
To systematically study multi-stage countercurrent process for Antarctic krill protein extracting and to optimize the multi-stage countercurrent technology, the solubility of Antarctic krill proteins after multi-step dissolution was explored firstly; multi-step extraction was investigated; and then multi-stage countercurrent system for protein extraction was carried out. In single step extraction, krill-to-water ratio and pH were chosen as 1:10 and 12.5 respectively, in order to extract more protein. In the multi-step dissolution process, the protein solubility of aqueous solution at pH 12.5 was 33.0 ± 0.8 mg/mL. Multi-step cross-flow processing testified the feasibility of multi-stage countercurrent assumption. Three-stage countercurrent method using krill-to-water ratio 1:10 extracted, 95.1 ± 0.6% protein from krill, where almost the same water as previous works. The total recovery yield of 67.9 ± 1.6% was achieved after precipitation at pH 4.5.
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Affiliation(s)
- Xiangming Qi
- College of Food Science and Engineering, Ocean University of China, Qingdao, 266003 China
| | - E. Liao
- College of Food Science and Engineering, Ocean University of China, Qingdao, 266003 China
- School of Food Science and Technology, Jiangnan University, Wuxi, 214122 China
| | - Kuo Zhao
- College of Food Science and Engineering, Ocean University of China, Qingdao, 266003 China
| | - Joe Mac Regenstein
- Department of Food Science, Cornell University, Ithaca, NY 14853-7201 USA
| | - Xiangzhao Mao
- College of Food Science and Engineering, Ocean University of China, Qingdao, 266003 China
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Bjørndal B, Bruheim I, Lysne V, Ramsvik MS, Ueland PM, Nordrehaug JE, Nygård OK, Berge RK. Plasma choline, homocysteine and vitamin status in healthy adults supplemented with krill oil: a pilot study. Scand J Clin Lab Invest 2018; 78:527-532. [PMID: 30261756 DOI: 10.1080/00365513.2018.1512716] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Plasma concentrations of metabolites along the choline oxidation and tryptophan degradation pathways have been linked to lifestyle diseases and dietary habits. This study aimed to investigate how krill oil, a source of ω-3 polyunsaturated fatty acids (PUFAs) with a high phosphatidylcholine content, affected these parameters. The pilot study was conducted as a 28 days intervention in 17 healthy volunteers (18-36 years), who received a supplement of 4.5 g krill oil per day, providing 833 mg ω-3 PUFAs, and 1750 mg phosphatidylcholine. Krill oil supplementation increased fasting plasma choline (+28.4%, p < .001), betaine (+26.6%, p < .001), dimethylglycine (+33.7%, p < .001) and sarcosine (+16.8%, p < .001), whereas no statistically significant changes were seen for plasma glycine, serine, methionine, total homocysteine, cysteine, cystathionine, methionine sulfoxide, folate, cobalamin, B2-, B3-, and B6 vitamers, tryptophan, kynurenines, nicotinamide, vitamin A and vitamin E. In summary, krill oil supplementation influenced choline metabolite levels, but not plasma metabolites of the tryptophan-kynurenine-nicotinamide pathways and vitamins. These observations should be confirmed in a placebo-controlled trial, including an ω-3 PUFA supplement without phospholipids to explore the potential additive effects of the different active ingredients.
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Affiliation(s)
- Bodil Bjørndal
- a Department of Clinical Science , University of Bergen , Bergen , Norway
| | - Inge Bruheim
- b Rimfrost AS , Fosnavåg , Norway.,c Møreforskning AS , Ålesund , Norway
| | - Vegard Lysne
- a Department of Clinical Science , University of Bergen , Bergen , Norway
| | - Marie S Ramsvik
- a Department of Clinical Science , University of Bergen , Bergen , Norway
| | - Per M Ueland
- a Department of Clinical Science , University of Bergen , Bergen , Norway
| | - Jan E Nordrehaug
- a Department of Clinical Science , University of Bergen , Bergen , Norway
| | - Ottar K Nygård
- a Department of Clinical Science , University of Bergen , Bergen , Norway.,d Department of Heart Disease , Haukeland University Hospital , Bergen , Norway.,e KG Jebsen Centre for Diabetes Research, University of Bergen , Bergen , Norway
| | - Rolf K Berge
- a Department of Clinical Science , University of Bergen , Bergen , Norway.,d Department of Heart Disease , Haukeland University Hospital , Bergen , Norway
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Weinstein BG, Irvine L, Friedlaender AS. Capturing foraging and resting behavior using nested multivariate Markov models in an air-breathing marine vertebrate. Mov Ecol 2018; 6:16. [PMID: 30250739 PMCID: PMC6146519 DOI: 10.1186/s40462-018-0134-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 07/16/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Matching animal movement with the behaviors that shape life history requires a rigorous connection between the observed patterns of space use and inferred behavioral states. As animal-borne dataloggers capture a greater diversity and frequency of three dimensional movements, we can increase the complexity of movement models describing animal behavior. One challenge in combining data streams is the different spatial and temporal frequency of observations. Nested movement models provide a flexible framework for gleaning data from long-duration, but temporally sparse, data sources. RESULTS Using a two-layer nested model, we combined geographic and vertical movement to infer traveling, foraging and resting behaviors of Humpback whales off the West Antarctic Peninsula. This approach refined previous work using only geographic data to delineate coarser behavioral states. Our results showed increased intensity in foraging activity in late season animals as the whales prepared to migrate north to tropical calving grounds. Our model also suggests strong diel variation in movement states, likely linked to daily changes in prey distribution. CONCLUSIONS Using a combination of two-dimensional and three-dimensional movement data, we highlight the connection between whale movement and krill availability, as well as the complex spatial pattern of whale foraging in productive polar waters.
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Affiliation(s)
- Ben G. Weinstein
- Department of Fisheries and Wildlife, Marine Mammal Institute, Oregon State University, 2030 Marine Science Drive, Newport, OR 97365 USA
| | - Ladd Irvine
- Department of Fisheries and Wildlife, Marine Mammal Institute, Oregon State University, 2030 Marine Science Drive, Newport, OR 97365 USA
| | - Ari S. Friedlaender
- Department of Fisheries and Wildlife, Marine Mammal Institute, Oregon State University, 2030 Marine Science Drive, Newport, OR 97365 USA
- Institute of Marine Sciences, Department of Ecology and Evolutionary Biology, UC Santa Cruz, 115 McAllister Way, Santa Cruz, CA 95060 USA
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Chen LF, Zhu GP. [Analysis of influence on spatial distribution of fishing ground for Antarctic krill fishery in the northern South Shetland Islands based on GWR model]. Ying Yong Sheng Tai Xue Bao 2018; 29:938-944. [PMID: 29722238 DOI: 10.13287/j.1001-9332.201803.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Based on Antarctic krill fishery and marine environmental data collected by scientific observers, using geographically weighted regression (GWR) model, we analyzed the effects of the factors with spatial attributes, i.e., depth of krill swarm (DKS) and distance from fishing position to shore (DTS), and sea surface temperature (SST), on the spatial distribution of fishing ground in the northern South Shetland Islands. The results showed that there was no significant aggregation in spatial distribution of catch per unit fishing effort (CPUE). Spatial autocorrelations (positive) among three factors were observed in 2010 and 2013, but were not in 2012 and 2016. Results from GWR model showed that the extent for the impacts on spatial distribution of CPUEs varied among those three factors, following the order DKS>SST>DTS. Compared to the DKS and DTS, the impact of SST on the spatial distribution of CPUEs presented adverse trend in the eastern and western parts of the South Shetland Islands. Negative correlations occurred for the spatial effects of DKS and DTS on distribution of CPUEs, though with inter-annual and regional variation. Our results provide metho-dological reference for researches on the underlying mechanism for fishing ground formation for Antarctic krill fishery.
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Affiliation(s)
- Lyu Feng Chen
- College of Marine Sciences, Shanghai Ocean University, Shanghai 201306, China
| | - Guo Ping Zhu
- College of Marine Sciences, Shanghai Ocean University, Shanghai 201306, China.,National Engineering Research Center for Oceanic Fisheries, Shanghai 201306, China.,Polar Marine Ecosystem Group, Ministry of Education Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources, Shanghai Ocean University, Shanghai 201306, China
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Tarroux A, Lydersen C, Trathan PN, Kovacs KM. Temporal variation in trophic relationships among three congeneric penguin species breeding in sympatry. Ecol Evol 2018; 8:3660-3674. [PMID: 29686847 PMCID: PMC5901183 DOI: 10.1002/ece3.3937] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 01/12/2018] [Accepted: 01/27/2018] [Indexed: 11/08/2022] Open
Abstract
Penguins are a monophyletic group in which many species are found breeding sympatrically, raising questions regarding how these species coexist successfully. Here, the isotopic niche of three sympatric pygoscelid penguin species was investigated at Powell Island, South Orkney Islands, during two breeding seasons (austral summers 2013–2014 and 2015–2016). Measurements of carbon (δ13C) and nitrogen (δ15N) stable isotope ratios were obtained from blood (adults) or feather (chicks) samples collected from Adélie Pygoscelis adeliae, chinstrap P. antarctica, and gentoo P. papua penguins. Isotopic niche regions (a proxy for the realized trophic niches) were computed to provide estimates of the trophic niche width of the studied species during the breeding season. The isotopic niche regions of adults of all three species were similar, but gentoo chicks had noticeably wider isotopic niches than the chicks of the other two species. Moderate to strong overlap in isotopic niche among species was found during each breeding season and for both age groups, suggesting that the potential for competition for shared food sources was similar during the two study years, although the actual level of competition could not be determined owing to the lack of data on resource abundance. Clear interannual shifts in isotopic niche were seen in all three species, though of lower amplitude for adult chinstrap penguins. These shifts were due to variation in carbon, but not nitrogen, isotopic ratios, which could indicate either a change in isotopic signature of their prey or a switch to an alternative food web. The main conclusions of this study are that (1) there is a partial overlap in the isotopic niches of these three congeneric species and that (2) they responded similarly to changes that likely occurred at the base of their food chain between the 2 years of the study.
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Affiliation(s)
- Arnaud Tarroux
- Norwegian Polar Institute Fram Centre Tromsø Norway.,Norwegian Institute for Nature Research Fram Centre Tromsø Norway
| | | | | | - Kit M Kovacs
- Norwegian Polar Institute Fram Centre Tromsø Norway
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Corsolini S, Ademollo N, Martellini T, Randazzo D, Vacchi M, Cincinelli A. Legacy persistent organic pollutants including PBDEs in the trophic web of the Ross Sea (Antarctica). Chemosphere 2017; 185:699-708. [PMID: 28732330 DOI: 10.1016/j.chemosphere.2017.07.054] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 06/29/2017] [Accepted: 07/11/2017] [Indexed: 05/22/2023]
Abstract
The ecological features of the Ross Sea trophic web are peculiar and different from other polar food webs, with respect to the use of habitat and species interactions; due to its ecosystem integrity, it is the world's largest Marine Protected Area, established in 2016. Polar organisms are reported to bioaccumulate lipophilic contaminant, viz persistent organic pollutants (POPs). Legacy POPs and flame retardants (polybrominated diphenyl ethers, PBDEs) were studied in key species of the Ross Sea (Euphausia superba, Pleuragramma antarctica) and their predators (Dissostichus mawsoni, Pygoscelis adeliae, Aptenodytes forsteri, Catharacta maccormicki, Leptonychotes weddellii). Gaschromatography revealed the presence of PCBs, HCB, DDTs, PBDEs in most of the samples; HCHs, dieldrin, Eldrin, non-ortho PCBs, PCDDs, PCDFs were detected only in some species. The average ∑PBDEs was 0.19-1.35 pg/g wet wt in the key-species and one-two order of magnitude higher in the predators. Penguins and skuas from an area where a long-term field camp is located showed higher BDE concentrations. The ΣDDTs was higher in the Antarctic toothfish (20 ± 6.73 ng/g wet wt) and in the South Polar skua (5.911 ± 3.425 ng/g wet wt). The TEQs were evaluated and the highest concentration was found in the Weddell seal, due to PCB169, 1,2,3,4,7,8-HxCDF, and 2,3,4,6,7,8-HxCDF. There was no significant relationship between the trophic level and the POP concentrations. Although low concentrations, organisms of the Ross Sea trophic web should be further studied: lack of information on some ecotoxicological features and human impacts including global change may distress the ecosystem with unpredictable effects.
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Affiliation(s)
- Simonetta Corsolini
- University of Siena, Department of Physics, Earth and Environmental Sciences, Via Mattioli, 4, 53100 Siena, Italy.
| | - Nicoletta Ademollo
- Water Research Institute (IRSA), National Research Council, Via Salaria Km 29.300, 00015 Monterotondo Scalo (RM), Italy
| | - Tania Martellini
- Department of Chemistry "Ugo Schiff", University of Florence, 50019 Sesto Fiorentino (Florence), Italy
| | - Demetrio Randazzo
- Department of Chemistry "Ugo Schiff", University of Florence, 50019 Sesto Fiorentino (Florence), Italy
| | - Marino Vacchi
- Institute of Marine Sciences (ISMAR), National Research Council, Via De Marini 6, 16149 Genova, Italy
| | - Alessandra Cincinelli
- Department of Chemistry "Ugo Schiff", University of Florence, 50019 Sesto Fiorentino (Florence), Italy
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Hou H, Wang S, Zhu X, Li Q, Fan Y, Cheng D, Li B. A novel calcium-binding peptide from Antarctic krill protein hydrolysates and identification of binding sites of calcium-peptide complex. Food Chem 2018; 243:389-95. [PMID: 29146354 DOI: 10.1016/j.foodchem.2017.09.152] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 09/27/2017] [Accepted: 09/29/2017] [Indexed: 11/22/2022]
Abstract
Trypsin was used for preparing peptides with high calcium-binding capacity from Antarctic krill. Hydroxyapatite chromatography (HAC), size-exclusion chromatography (SEC), and reversed phase high performance liquid chromatography (RP-HPLC) were used to capture and purify calcium-binding peptides. The peptide sequence was determined to be VLGYIQIR (N- to C-terminal, MW = 960.58 Da), using LTQ Orbitrap XL. According to the results of FTIR and mass spectrometry, chelating site of calcium ions may possibly involve the carbonal or amino groups of Gln, Ile and Arg residues. Molecular dynamic simulation showed the conformation of peptide was markedly varied, and the distance between calcium ion and Gln and Ile residues was changing all the time. However, the distance between calcium ion and carboxyl oxygen of arginine residues was not changed significantly from 2 ns to 100 ns. Identified peptide can be used as a novel calcium supplement.
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Weinstein BG, Friedlaender AS. Dynamic foraging of a top predator in a seasonal polar marine environment. Oecologia 2017; 185:427-35. [PMID: 28914358 DOI: 10.1007/s00442-017-3949-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 08/30/2017] [Indexed: 02/05/2023]
Abstract
The seasonal movement of animals at broad spatial scales provides insight into life-history, ecology and conservation. By combining high-resolution satellite-tagged data with hierarchical Bayesian movement models, we can associate spatial patterns of movement with marine animal behavior. We used a multi-state mixture model to describe humpback whale traveling and area-restricted search states as they forage along the West Antarctic Peninsula. We estimated the change in the geography, composition and characteristics of these behavioral states through time. We show that whales later in the austral fall spent more time in movements associated with foraging, traveled at lower speeds between foraging areas, and shifted their distribution northward and inshore. Seasonal changes in movement are likely due to a combination of sea ice advance and regional shifts in the primary prey source. Our study is a step towards dynamic movement models in the marine environment at broad scales.
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Belcher A, Tarling GA, Manno C, Atkinson A, Ward P, Skaret G, Fielding S, Henson SA, Sanders R. The potential role of Antarctic krill faecal pellets in efficient carbon export at the marginal ice zone of the South Orkney Islands in spring. Polar Biol 2017; 40:2001-13. [PMID: 32009725 DOI: 10.1007/s00300-017-2118-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Revised: 03/24/2017] [Accepted: 03/26/2017] [Indexed: 11/23/2022]
Abstract
Antarctic krill (Euphausia superba) play a central role in the food web of the Southern Ocean, forming a link between primary production and large predators. Krill produce large, faecal pellets (FP) which can form a large component of mesopelagic particulate organic carbon (POC) fluxes. However, the patchy distribution of krill swarms, highly variable pellet composition, and variable sinking and attenuation rates means that these episodic, but potentially large, carbon fluxes are difficult to sample or model. We measured particle flux and type using Marine Snow Catchers (MSC) in the marginal ice zone near the South Orkneys, Antarctica. Krill FP were the dominant component of the POC flux in the upper 200 m (typically 60–85%). FP sinking velocities measured onboard were highly variable (15–507 m d−1) but overall high, with mean equivalent velocities of 172, 267, and 161 m d−1 at our three stations. The high numbers of krill FP sinking through the mesopelagic suggest that krill FP can be transferred efficiently and/or that rates of krill FP production are high. We compared our direct MSC-derived estimates of krill FP POC flux (33–154 mg C m−2 d−1) and attenuation to estimates of krill FP production based on previous measurements of krill density and literature FP egestion rates, and estimated net krill FP attenuation rates in the upper mesopelagic. Calculated attenuation rates are sensitive to krill densities in the overlying water column but suggest that krill FP could be transferred efficiently through the upper mesopelagic, and, in agreement with our MSC attenuation estimates, could make large contributions to bathypelagic POC fluxes. Our study contrasts with some others which suggest rapid FP attenuation, highlighting the need for further work to constrain attenuation rates and assess how important the contribution of Antarctic krill FP could be to the Southern Ocean biological carbon pump.
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