Ross Sea

罗斯海
  • 文章类型: Journal Article
    南极洲拥有地球上一些最孤立和极端的环境,隐藏了全球动物病毒圈中一个很大程度上未经探索和独特的组成部分。为了了解这些极地物种中病毒的多样性和进化史,我们从11种南极鱼类中确定了g的病毒体,并从跨越Perciformes的罗斯海地区收集了248个样本,Gadiformes,和天蝎座命令。大陆向南移动和降温温度>2000万年前导致生物多样性减少和一些海洋动物的辐射,比如类鱼类。尽管极地地区寄主物种丰富度下降,我们揭示了罗斯海鱼类中令人惊讶的复杂病毒多样性,每个宿主物种和个体的病毒类型和数量与温暖的海洋环境中宿主群落多样性较高的鱼类相当。我们还观察到更多的密切相关的病毒可能代表最近和历史宿主转换事件的实例在Perciformes(所有notethenioids)比在Gadiformes,表明在此顺序下的快速物种形成事件产生了密切相关的宿主物种,几乎没有跨物种传播的遗传障碍。此外,我们在沙粒病毒中发现了新的基因组变异,其分裂的核蛋白序列含有稳定的螺旋结构,表明病毒蛋白对极端温度的潜在适应。这些发现增强了我们对病毒进化和病毒与宿主相互作用以应对环境变化的理解,特别是在多样性较低的生态系统中,这些生态系统更容易受到人为和气候变化的影响。
    Antarctica harbours some of the most isolated and extreme environments on Earth, concealing a largely unexplored and unique component of the global animal virosphere. To understand the diversity and evolutionary histories of viruses in these polar species, we determined the viromes of gill metatranscriptomes from 11 Antarctic fish species with 248 samples collected from the Ross Sea region spanning the Perciformes, Gadiformes, and Scorpaeniformes orders. The continent\'s shift southward and cooling temperatures >20 million years ago led to a reduction in biodiversity and subsequent radiation of some marine fauna, such as the notothenioid fishes. Despite decreased host species richness in polar regions, we revealed a surprisingly complex virome diversity in Ross Sea fish, with the types and numbers of viruses per host species and individuals sampled comparable to that of fish in warmer marine environments with higher host community diversity. We also observed a higher number of closely related viruses likely representing instances of recent and historic host-switching events among the Perciformes (all notothenioids) than in the Gadiformes, suggesting that rapid speciation events within this order generated closely related host species with few genetic barriers to cross-species transmission. Additionally, we identified novel genomic variation in an arenavirus with a split nucleoprotein sequence containing a stable helical structure, indicating potential adaptation of viral proteins to extreme temperatures. These findings enhance our understanding of virus evolution and virus-host interactions in response to environmental shifts, especially in less diverse ecosystems that are more vulnerable to the impacts of anthropogenic and climate changes.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    订单IsopodaLatreille,1816年由陆地上发生的物种组成,海洋和淡水环境。在南大洋(SO),这个群体是最特殊的,发生在所有深度。异足动物生物地理学,尽管自第一次南极探险以来一直在研究,从地理角度来看仍然鲜为人知,并且在SO的特定部门中,某些群体的发生差距很大。在本文中,我们更新罗斯海(RS)和一些南极周边地区的等足类清单,如南奥克尼群岛(SOI)和南桑威奇群岛(SSI),基于对意大利国家南极博物馆(MNA,热那亚部分)。
    共研究了来自15个不同探险的279个MNA样品。从这种材料中,由419个样本组成,确定了41种公认的物种,分布在24科51属中。将这些新获得的信息与GBIF(全球生物多样性信息设施)和OBIS(海洋生物多样性信息系统)门户进行比较,罗斯海首次报道了15种物种,罗斯海海洋保护区的5个新记录.所有记录都是TerraNova湾地区的新记录,以前从未为其制作过该组的清单。
    UNASSIGNED: The order Isopoda Latreille, 1816 consists of species occurring in terrestrial, marine and freshwater environments. In the Southern Ocean (SO), this group is amongst the most speciose and occur at all depths. Isopoda biogeography, despite being studied since the first Antarctic expeditions, is still poorly known from a geographical point of view and shows large occurrence gaps for some groups in specific sectors of the SO. In this paper, we update the isopod checklists of the Ross Sea (RS) and of some peri-Antarctic areas, such as the South Orkney Islands (SOI) and the South Sandwich Islands (SSI), based on the study of museum vouchers curated by the Italian National Antarctic Museum (MNA, Section of Genoa).
    UNASSIGNED: A total of 279 MNA samples from 15 different expeditions were studied. From this material, consisting of 419 specimens, 41 accepted species distributed in 24 families and 51 genera were identified. Comparing this newly-obtained information with the GBIF (Global Biodiversity Information Facility) and OBIS (Ocean Biodiversity Information System) portal, 15 species are here reported for the first time in the Ross Sea, with five new records in the Ross Sea Marine Protected Area. All records are new for the Terra Nova Bay area, for which a checklist of this group has never been produced before.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    微生物在塑料聚合物上的定植已经得到了广泛的探索,然而,南极环境中生物膜群落的时间动态几乎是未知的。作为填补这一知识空白的贡献,在罗斯海的四个沿海地点调查了与聚氯乙烯(PVC)和聚乙烯(PE)板淹没在5m深度并在3、9和12个月后收集的生物膜的结构特征和微生物多样性。12个月后取回放置在5和20m处的其他面板。通过FTIR-ATR和拉曼(通过表面增强拉曼散射,SERS)光谱学。通过催化报告物沉积荧光原位杂交(CARD-FISH)和共聚焦激光扫描显微镜(CLSM)在单细胞水平定量细菌群落组成;通过16SrRNA基因测序评估微生物多样性。这种多学科方法为生物污染过程中的微生物群落动态提供了新的见解,在罗斯海的塑料基质上释放生物膜多样性和时间演替的光。发现自由生活和微生物生物膜群落之间存在显着差异,与PE相比,PVC的社区组成更加巩固和结构化。酪氨酸的光谱特征,多糖,核酸和脂质表征了PVC相关的生物膜。假单胞菌(在γ变形杆菌中)和α变形杆菌在微生物生物膜群落中占主导地位。有趣的是,在路湾,靠近意大利“马里奥·祖切利”研究站,生物膜生长-已经在夏季观察到,经过3个月的浸没-之后继续导致大量的微生物丰度在冬季结束(12个月后)。三个月后,在RoadBay发现的Gammaproteobacteria百分比高于未受影响的站点。这些观察结果使我们假设,在该地点,前3个月中产生的微生物污垢可以作为启动先驱社区,刺激冬季的连续生长。
    Microbial colonization on plastic polymers has been extensively explored, however the temporal dynamics of biofilm community in Antarctic environments are almost unknown. As a contribute to fill this knowledge gap, the structural characteristics and microbial diversity of the biofilm associated with polyvinyl chloride (PVC) and polyethylene (PE) panels submerged at 5 m of depth and collected after 3, 9 and 12 months were investigated in four coastal sites of the Ross Sea. Additional panels placed at 5 and 20 m were retrieved after 12 months. Chemical characterization was performed by FTIR-ATR and Raman (through Surface-Enhanced Raman Scattering, SERS) spectroscopy. Bacterial community composition was quantified at a single cell level by Catalyzed Reporter Deposition Fluorescence In Situ Hybridization (CARD-FISH) and Confocal Laser Scanning Microscopy (CLSM); microbial diversity was assessed by 16S rRNA gene sequencing. This multidisciplinary approach has provided new insights into microbial community dynamics during biofouling process, shedding light on the biofilm diversity and temporal succession on plastic substrates in the Ross Sea. Significant differences between free-living and microbial biofilm communities were found, with a more consolidated and structured community composition on PVC compared to PE. Spectral features ascribable to tyrosine, polysaccharides, nucleic acids and lipids characterized the PVC-associated biofilms. Pseudomonadota (among Gamma-proteobacteria) and Alpha-proteobacteria dominated the microbial biofilm community. Interestingly, in Road Bay, close to the Italian \"Mario Zucchelli\" research station, the biofilm growth - already observed during summer season, after 3 months of submersion - continued afterwards leading to a massive microbial abundance at the end of winter (after 12 months). After 3 months, higher percentages of Gamma-proteobacteria in Road Bay than in the not-impacted site were found. These observations lead us to hypothesize that in this site microbial fouling developed during the first 3 months could serve as a starter pioneering community stimulating the successive growth during winter.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    浮游的分布数据,这里提供了在2018-2019年意大利国家南极计划(PNRA)第XXXIV次对罗斯海地区的探险框架内收集的底栖和交感co足类动物。这些事件对应于从意大利研究站“MarioZucchelli”(MZS)的海水淡化厂使用的25μm过滤器收集的标本,位于TerraNova湾地区(TNB;罗斯海,南极洲)。该数据集是对南极生物多样性门户的贡献,海洋生物地理信息系统(AntOBIS)和全球生物多样性信息设施南极生物多样性信息设施(ANTABIF)的主题南极节点。上传数据集并与SCAR-AntOBIS数据库(SCAR-MarBIN的地理空间组件)集成。使用数据时,请遵循SCAR数据政策(ISSN1998-0337)的指导原则。如果您对此数据集有任何疑问,请通过元数据中提供的联系信息或数据-生物多样性-aq@naturalsciences与我们联系。.数据集的问题可以在生物多样性-aqGitHub项目中报告。
    我们描述了由安装在意大利研究站“MarioZucchelli”的海水淡化装置(DU)中的过滤器采样的海洋co足类TerraNovaBay的多样性。DU的进气管的开口位于4m的深度处,并且允许总共2,116个样本被采样和识别。此外,在同一地区报道了co足类属和种的新发生记录。我们概述了TNB报告的海洋co足类多样性。总共2,116个个体对应于14属和15种,并由该数据集中的136个发生记录表示。TNB地区的新记录约占物种总数的52%。本数据论文的出版由比利时科学政策办公室(BELSPO,合同n°FR/36/AN1/AntaBIS)在欧盟生命观察框架中作为对SCAR南极生物多样性门户的贡献(生物多样性。aq).
    UNASSIGNED: Distributional data on planktonic, benthic and sympagic copepods collected in the framework of the XXXIVth Expeditions of the Italian National Antarctic Programme (PNRA) to the Ross Sea sector from 2018-2019 are here provided. These occurrences correspond to specimens collected from the 25 μm filters used in the desalination plant of the Italian research station \"Mario Zucchelli\" (MZS), located in the Terra Nova Bay area (TNB; Ross Sea, Antarctica). This dataset is a contribution to the Antarctic Biodiversity Portal, the thematic Antarctic node for both the Ocean Biogeographic Information System (AntOBIS) and the Global Biodiversity Information Facility Antarctic Biodiversity Information Facility (ANTABIF). The dataset was uploaded and integrated with the SCAR-AntOBIS database (the geospatial component of SCAR-MarBIN). Please follow the guidelines from the SCAR Data Policy (ISSN 1998-0337) when using the data. If you have any questions regarding this dataset, please contact us via the contact information provided in the metadata or via data-biodiversity-aq@naturalsciences.be. Issues with the dataset can be reported at the biodiversity-aq GitHub project.
    UNASSIGNED: We describe the diversity of marine copepods Terra Nova Bay sampled by the filters installed in the desalination unit (DU) of the Italian research station \"Mario Zucchelli\" described in recent work. The opening of the intake pipe of the DU is positioned at a depth of 4 m and allowed a total of 2,116 specimens to be sampled and recognised. In addition, new occurrence records of copepod genera and species are reported in the same zone. We provide an overview of the marine copepod diversity reported for TNB. The total of 2,116 individuals corresponds to 14 genera and 15 species and is represented by 136 occurrence records in this dataset. Around 52% of the total number of species are new records for the TNB area. The publication of this data paper was funded by the Belgian Science Policy Office (BELSPO, contract n°FR/36/AN1/AntaBIS) in the Framework of EU-Lifewatch as a contribution to the SCAR Antarctic biodiversity portal (biodiversity.aq).
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    南极物种如何面临历史和新的压力仍未得到充分调查,野生动植物面临的风险仍在很大程度上未知。Adélie企鹅Pygoscelisadeliae是众所周知的生物指标和南极生态系统变化的前哨,煤矿里真正的金丝雀.免疫血液学参数已被证明可以检测野生动物的应激,鉴于他们快速的生理反应,使他们能够跟踪环境变化,从而推断栖息地的质量。这里,我们调查了在红血球核异常(ENAs)和白细胞(WBCs)的变化企鹅从三个集群在罗斯海,根据地理位置评估免疫血液学参数,育种阶段,和企鹅的个体特征,如性别,身体状况和巢穴质量。在羽毛中分析了汞(Hg)的浓度以及碳和氮的稳定同位素(作为企鹅营养生态的代表),以研究压力生物标志物与Adélie企鹅中Hg污染之间的关系。不支持菌落和繁殖阶段作为免疫血液学参数的预测因子。雄性企鹅的ENAs和WBC分别比雌性企鹅高出约30%和约20%。身体状况影响WBC,企鹅在最佳条件下的WBC水平比在最差条件下的高~22%。巢位置影响微核(MNs)的比例,内筑巢的企鹅的MNs比例是在外围位置筑巢的企鹅的三倍以上。异源粒细胞:淋巴细胞(H:L)比率不受任何上述预测因子的影响。预计在不久的将来,南极野生动植物中作为压力源的多种因素将显着增加,因此,旨在评估企鹅种群健康状况的广泛监测是强制性的。
    How Antarctic species are facing historical and new stressors remains under-surveyed and risks to wildlife are still largely unknown. Adélie penguins Pygoscelis adeliae are well-known bioindicators and sentinels of Antarctic ecosystem changes, a true canary in the coal mine. Immuno-haematological parameters have been proved to detect stress in wild animals, given their rapid physiological response that allows them tracking environmental changes and thus inferring habitat quality. Here, we investigated variation in Erythrocyte Nuclear Abnormalities (ENAs) and White Blood Cells (WBCs) in penguins from three clustered colonies in the Ross Sea, evaluating immuno-haematological parameters according to geography, breeding stage, and individual penguin characteristics such as sex, body condition and nest quality. Concentrations of mercury (Hg) and stable isotopes of carbon and nitrogen (as proxies of the penguin\'s trophic ecology) were analysed in feathers to investigate the association between stress biomarkers and Hg contamination in Adélie penguins. Colony and breeding stage were not supported as predictors of immuno-haematological parameters. ENAs and WBCs were respectively ∼30 % and ∼20 % higher in male than in female penguins. Body condition influenced WBCs, with penguins in the best condition having a ∼22 % higher level of WBCs than those in the worst condition. Nest position affected the proportion of micronuclei (MNs), with inner-nesting penguins having more than three times the proportion of MNs than penguins nesting in peripheral positions. Heterophils:Lymphocytes (H:L) ratio was not affected by any of the above predictors. Multiple factors acting as stressors are expected to increase prominently in Antarctic wildlife in the near future, therefore extensive monitoring aimed to assess the health status of penguin populations is mandatory.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    与许多极地地区不同,在卫星时代,南大洋罗斯海部分的海冰季节的空间范围和持续时间有所增加。同时,阿德利企鹅的种群,海冰义务,在该地区保持稳定或增加。阿德利企鹅种群增长与海冰浓度(SIC)之间的关系很复杂,海冰驱动不同,有时形成对比,人口模式。阿德利企鹅每年都要经历一次完全的蜕皮,在繁殖季节后不久禁食时更换所有的羽毛。与大多数企鹅不同,大多数Adélies被认为在海冰上蜕皮,远离繁殖地,这使得这一时期的研究特别困难。这里,我们评估了以下假设:高SIC的持久性区域为Adélie企鹅提供了重要的蜕皮栖息地。我们分析了2017年至2019年在罗斯海的两个殖民地全年部署的195只成年企鹅的地理定位潜水记录仪的数据。我们通过检测繁殖后潜水活动中的扩展间隙来识别蜕皮,并使用相关位置来定义两个关键的蜕皮区域。遥感数据表明,在研究过程中,蜕皮期间的SIC异常低,并且自1980年以来,初级蜕皮区域的SIC有所下降。Further,在20年以上的蜕皮地区,企鹅到繁殖菌落的年回报率与SIC呈正相关。这些结果共同表明,在Adélie企鹅蜕皮期间的海冰条件可能代表了以前被低估的成年生存年度瓶颈。
    Unlike in many polar regions, the spatial extent and duration of the sea ice season have increased in the Ross Sea sector of the Southern Ocean during the satellite era. Simultaneously, populations of Adélie penguins, a sea ice obligate, have been stable or increasing in the region. Relationships between Adélie penguin population growth and sea ice concentration (SIC) are complex, with sea ice driving different, sometimes contrasting, demographic patterns. Adélie penguins undergo a complete molt annually, replacing all their feathers while fasting shortly after the breeding season. Unlike most penguin species, a majority of Adélies are thought to molt on sea ice, away from the breeding colonies, which makes this period particularly difficult to study. Here, we evaluate the hypothesis that persistent areas of high SIC provide an important molting habitat for Adélie penguins. We analyzed data from geolocating dive recorders deployed year-round on 195 adult penguins at two colonies in the Ross Sea from 2017 to 2019. We identified molt by detecting extended gaps in postbreeding diving activity and used associated locations to define two key molting areas. Remotely sensed data indicated that SIC during molt was anomalously low during the study and has declined in the primary molt area since 1980. Further, annual return rates of penguins to breeding colonies were positively correlated with SIC in the molt areas over 20 y. Together these results suggest that sea ice conditions during Adélie penguin molt may represent a previously underappreciated annual bottleneck for adult survival.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    季节性迁移,在年度气候周期和资源变化的推动下,是跨分类群物种的生活史和生态学的关键部分。通过影响移动所需的能量,风和洋流等外力通常是使个体暴露于不同资源的迁徙途径的关键驱动因素,环境条件,以及影响个人健身和人口动态的竞争压力。尽管与风和洋流有关的野生动植物运动已相对较好地了解,海冰场内的运动研究要少得多,尽管海冰是极地生态不可或缺的一部分。罗斯海南部的Adélie企鹅(Pygoscelisadeliae),南极洲,目前存在于其范围的最南端,并且经历了该物种已知的最长(〜12000km)冬季迁徙。在罗斯海内部和北部,罗斯环流推动了海洋环流和海冰的大规模运动。我们使用遥感海冰运动数据以及基于地理位置的企鹅运动数据来检验以下假设:企鹅使用回旋驱动的海冰运动来帮助其迁移。我们发现,当企鹅的运动矢量与海冰的运动矢量对齐时,企鹅的运动距离更大(即,冰支持)和获得的冰支持量取决于企鹅采取的路线。我们还发现,在我们检查的三年中的两年中,走东部路线的鸟类明显向北移动,与那些年海冰的更高速度相吻合。我们将我们的发现与在利用空气或水流旅行的迁徙物种中观察到的模式进行比较,并与其他研究进行比较,这些研究表明海洋/海冰循环模式对罗斯海内野生动物运动和生活史模式的重要性。海冰的变化可能不仅对能源消耗产生影响,而且对能源支出产生影响。通过改变迁移和运动路径,这个地区存在的生态相互作用。本文受版权保护。保留所有权利。
    Seasonal migration, driven by shifts in annual climate cycles and resources, is a key part of the life history and ecology of species across taxonomic groups. By influencing the amount of energy needed to move, external forces such as wind and ocean currents are often key drivers of migratory pathways exposing individuals to varying resources, environmental conditions, and competition pressures impacting individual fitness and population dynamics. Although wildlife movements in connection with wind and ocean currents are relatively well understood, movements within sea-ice fields have been much less studied, despite sea ice being an integral part of polar ecology. Adélie penguins (Pygoscelis adeliae) in the southern Ross Sea, Antarctica, currently exist at the southernmost edge of their range and undergo the longest (~12,000 km) winter migration known for the species. Within and north of the Ross Sea, the Ross Gyre drives ocean circulation and the large-scale movement of sea ice. We used remotely sensed sea-ice movement data together with geolocation-based penguin movement data to test the hypothesis that penguins use gyre-driven sea-ice movement to aid their migration. We found that penguins traveled greater distances when their movement vectors were aligned with those of sea ice (i.e., ice support) and the amount of ice support received depended on which route a penguin took. We also found that birds that took an eastern route traveled significantly further north in two of the 3 years we examined, coinciding with higher velocities of sea ice in those years. We compare our findings to patterns observed in migrating species that utilize air or water currents for their travel and with other studies showing the importance of ocean/sea-ice circulation patterns to wildlife movement and life history patterns within the Ross Sea. Changes in sea ice may have consequences not only for energy expenditure but, by altering migration and movement pathways, to the ecological interactions that exist in this region.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    监测南极地区微塑料污染的发生是研究站实施废物监管政策措施的关键。南极鱼Trematomusbernachii是建立微塑料污染并调查南极地区微塑料浓度和类型随时间变化的合适物种。本文共78条鱼,分析了在罗斯海(南极洲)举行的第37次意大利南极考察(2021-2022)期间捕获的。通过拉曼光谱鉴定了不同的微纤维和染料,并将结果与1998年采样的鱼的结果进行了比较。相对于天然纤维,聚合物类型的差异以合成纤维为主。这些变化似乎与过去二十年来南极洲人类活动的增加有关,并强调需要改善在该地区运作的众多研究站的环境可持续性。
    Monitoring the occurrence of microplastic contamination in the Antarctic area is the key to implement policy measures for waste regulations in the research stations. Antarctic fish Trematomus bernachii is a suitable species for establishing microplastic contamination and for investigating changes over time in the concentration and type of microplastics in the Antarctic region. In this paper a total of 78 fish, caught during the 37th Italian Antarctic expedition (2021-2022) in the Ross Sea (Antarctica) were analysed. Different microfibers and dyes were identified by Raman spectroscopy and the results were compared with those obtained for fish sampled in 1998. Differences in polymer type emerged with a predominance of synthetic fibers with respect to natural ones. These changes appear to be related to the increased human activities in the Antarctica over the last twenty years and highlights the need to improve the environmental sustainability of the numerous research stations operating throughout that area.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    南极微囊藻在南大洋形成大量的春季花朵,与高浓度的二甲基磺丙酸酯(DMSP)相吻合,二甲基亚砜(DMSO),二甲基硫醚(DMS),和丙烯酸酯。我们确定了这些化合物的浓度如何在暴露于光限制的南极黑曲霉培养物的生长过程中发生变化,次饱和,和饱和的PAR辐照度。每升细胞体积(CV)的细胞DMSP浓度范围为199至403mmol·LCV-1,在光限制PAR下观察到的最高浓度。细胞丙烯酸酯浓度没有随着辐照度水平或生长的变化而明显变化,范围在18至45mmol·LCV-1之间,构成约0.2%-2.8%的细胞碳。在每个细胞的基础上,溶解的丙烯酸酯和DMSO在指数生长期间随辐照度大幅增加,范围从0.91到3.15和0.24到1.39fmol·cell-1,分别,表明这些化合物大量出口到溶解相中。平均细胞DMSO:DMSP比率在分批生长的指数期和稳定期之间增加了7.6倍,细胞DMSO增加3至13倍,可能是由DMSP和DMS与活性氧(ROS)的非生物反应形成的。在mM水平,细胞DMSP和丙烯酸酯被认为是在南极洲不受氧化应激或ROS变化调节的事实上的抗氧化剂。相反,细胞DMSP浓度可能受其他生理过程控制,包括通过丙烯酸酯去除过量碳的溢流机制,DMS,和DMSO在由物理压力或营养限制引起的不平衡生长期间。一起,这些化合物应通过维持细胞功能和减少氧化应激来帮助南极疟原虫适应一系列PAR辐照度。
    Phaeocystis antarctica forms extensive spring blooms in the Southern Ocean that coincide with high concentrations of dimethylsulfoniopropionate (DMSP), dimethylsulfoxide (DMSO), dimethylsulfide (DMS), and acrylate. We determined how concentrations of these compounds changed during the growth of axenic P. antarctica cultures exposed to light-limiting, sub-saturating, and saturating PAR irradiances. Cellular DMSP concentrations per liter cell volume (CV) ranged between 199 and 403 mmol · LCV -1 , with the highest concentrations observed under light-limiting PAR. Cellular acrylate concentrations did not change appreciably with a change in irradiance level or growth, ranging between 18 and 45 mmol · LCV -1 , constituting an estimated 0.2%-2.8% of cellular carbon. Both dissolved acrylate and DMSO increased substantially with irradiance during exponential growth on a per-cell basis, ranging from 0.91 to 3.15 and 0.24 to 1.39 fmol · cell-1 , respectively, indicating substantial export of these compounds into the dissolved phase. Average cellular DMSO:DMSP ratios increased 7.6-fold between exponential and stationary phases of batch growth, with a 3- to 13-fold increase in cellular DMSO likely formed from abiotic reactions of DMSP and DMS with reactive oxygen species (ROS). At mM levels, cellular DMSP and acrylate are proposed to serve as de facto antioxidants in P. antarctica not regulated by oxidative stress or changes in ROS. Instead, cellular DMSP concentrations are likely controlled by other physiological processes including an overflow mechanism to remove excess carbon via acrylate, DMS, and DMSO during times of unbalanced growth brought on by physical stress or nutrient limitation. Together, these compounds should aid P. antarctica in adapting to a range of PAR irradiances by maintaining cellular functions and reducing oxidative stress.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    有机碳的组成对于确定生物碳泵的效率可能很重要。然而,目前在罗斯海中,有关每个藻类组合的信息很少。这里,我们调查了有机碳组成的季节性变化和每种有机碳的相对丰度,包括颗粒有机碳(POC),溶解有机碳(DOC)和透明的外聚合物颗粒(TEP),以罗斯海中不同的藻类为特征。POC和DOC对总有机碳的平均贡献(TOC=POC+DOC)在2019年1月中旬分别为13.8±3.7%和86.2±3.7%,2018年2月至3月分别为20.9±4.1%和79.1±4.1%。1月中旬TEP(TEP-C)的碳含量占POC和TOC的19.6±11.7%和4.6±7.0%,2-3月为36.2±14.8%和9.0±6.7%,分别。我们发现浮游植物盛开阶段的有机碳组成受到季节变化的影响,物理特性,浮游植物群落结构。DOC浓度和对TOC的贡献随着浮游植物细胞在1月中旬衰老而增加,而在2月至3月浮游植物相对活跃时下降。从2月到3月,加深的混合层深度促进了TEP的形成,随后增加了TEP的贡献。无论采样季节如何,每单位Chl-a的所有有机碳浓度在南极P.1月中旬,南极洲富集站的DOC对TOC的贡献相应较高,这表明南极洲对罗斯海的DOC贡献也很重要。由于气候变化,罗斯海的环境特征和浮游植物群落结构的快速变化可能会影响共生层的有机碳库,从而确定生物泵的效率。
    The compositions of organic carbon could be important in determining biological carbon pump efficiency. However, little information on them in relation to each algal assemblage is currently available in the Ross Sea. Here, we investigated the seasonal variations in organic carbon composition and the relative abundance of each organic carbon, including particulate organic carbon (POC), dissolved organic carbon (DOC), and transparent exopolymer particles (TEPs), characterized by different algal groups in the Ross Sea. The average POC and DOC contributions to the total organic carbon (TOC = POC + DOC) were 13.8 ± 3.7 % and 86.2 ± 3.7 % in mid-January 2019 and 20.9 ± 4.1 % and 79.1 ± 4.1 % in February-March 2018, respectively. The carbon content of TEP (TEP-C) contributed 19.6 ± 11.7 % and 4.6 ± 7.0 % of POC and TOC in mid-January and 36.2 ± 14.8 % and 9.0 ± 6.7 % in February-March, respectively. We found that the organic carbon compositions were affected by seasonal variations in the phytoplankton bloom phase, physical characteristics, and phytoplankton community structure. DOC concentrations and contributions to the TOC increased as phytoplankton cells became senescent in mid-January and decreased in February-March when phytoplankton were relatively active. From February-March, the deepened mixed layer depth encouraged TEP formation, subsequently increasing the TEP contributions. Regardless of the sampling season, all organic carbon concentrations per unit Chl-a were significantly higher in P. antarctica-abundant groups. The DOC contributions to the TOC were correspondingly higher at the P. antarctica-abundant stations in mid-January, which indicates that P. antarctica could be also important in the DOC contributions in the Ross Sea. The rapid alteration in environmental characteristics and phytoplankton community structures in the Ross Sea due to climate change could affect the organic carbon pool at the euphotic layer which consequently could determine the efficiency of the biological pump.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

公众号