Harmful Algae最新文献_第6页

Combined effects of CO2 and nitrogen on the stoichiometry of toxin synthesis in a harmful cyanobacterium CO2和氮对有害蓝藻毒素合成化学计量学的联合影响

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2025-12-01 Epub Date: 2025-09-04 DOI: 10.1016/j.hal.2025.102964

Savannah Sarkis , Jing Liu , Jef Huisman , Uwe John , Jolanda M.H. Verspagen , Dedmer B. Van de Waal

The increase in frequency and intensity of harmful cyanobacterial blooms in freshwater ecosystems over past decades has been attributed to anthropogenic influence, notably eutrophication and climate change. Microcystis is among the most widespread cyanobacterial bloom-forming genera, some strains of which can produce a range of microcystin variants having different toxicities. The synthesis of microcystins (MCs) is closely linked to carbon and nitrogen metabolism as microcystin variants differ in their nitrogen:carbon ratio. Thus, changes in availability of both CO₂ and nitrogen may impact microcystin production and composition. While the separate effects of CO₂ and nitrogen have been documented, their combined effect is less understood. We therefore assessed the effects of a CO₂ gradient at both nitrogen-replete and -deplete conditions on cellular nitrogen and carbon contents, N:C stoichiometry and microcystin synthesis in three Microcystis aeruginosa strains. We observed an interactive effect of increasing CO₂ concentrations with nitrogen availability across strains. Specifically, with increasing CO₂ availability, cellular N:C stoichiometry decreased under nitrogen-deplete conditions from 0.14 to 0.07 but increased under nitrogen-replete conditions from 0.11 to 0.17. Although total cellular microcystin content remained largely unaffected by both CO₂ and nitrogen despite shifts in N:C stoichiometry, changes in variant composition were consistent across strains and followed a stoichiometrically predictable pattern. N-rich but less toxic microcystin variants were favored at high cellular N:C ratios (e.g. MC-RR reached up to 44 % of total MC at highest N:C ratios), whereas relatively less N-containing but more toxic variants became more prevalent at low N:C ratios (e.g. MC-LW shifted from 9 % to 36 % of total MC for one of the strains). This study shows that shifts in CO₂ and nitrogen availability affect cellular N:C stoichiometry and alter microcystin composition, which may cause changes in the toxicity of cyanobacterial blooms.

过去几十年来，淡水生态系统中有害蓝藻爆发的频率和强度增加归因于人为影响，特别是富营养化和气候变化。微囊藻是最广泛的蓝藻属之一，其中一些菌株可以产生一系列具有不同毒性的微囊藻毒素变体。微囊藻毒素（microcystin, MCs）的合成与碳氮代谢密切相关，因为微囊藻毒素变体的氮碳比不同。因此，二氧化碳和氮可用性的变化可能会影响微囊藻毒素的产生和组成。虽然二氧化碳和氮的单独影响已被记录在案，但它们的综合影响却鲜为人知。因此，我们评估了在充氮和缺氮条件下CO2梯度对三种铜绿微囊藻菌株细胞氮和碳含量、氮碳化学计量和微囊藻毒素合成的影响。我们观察到CO2浓度的增加与菌株间氮有效性的相互作用。具体来说，随着CO2有效性的增加，细胞N:C化学计量在缺氮条件下从0.14下降到0.07，而在充氮条件下从0.11上升到0.17。尽管细胞微囊藻毒素的总含量在很大程度上不受CO2和氮的影响，尽管N:C的化学计量变化，变异成分的变化在菌株之间是一致的，并遵循化学计量可预测的模式。在高细胞N:C比下，富氮但毒性较低的微囊藻毒素变异更受青睐（例如，在最高N:C比下，MC- rr达到总MC的44%），而在低N:C比下，相对含氮较少但毒性较强的微囊藻毒素变异更普遍（例如，MC- lw从其中一个菌株的总MC的9%转移到36%）。该研究表明，CO2和氮有效性的变化会影响细胞N:C化学计量，并改变微囊藻毒素的组成，这可能导致蓝藻华毒性的变化。

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引用次数: 0

Ship-based eDNA tracking unveils early dispersal patterns and microecological dynamics of Ulva prolifera micropropagules in yellow sea green tide outbreaks 基于船舶的eDNA追踪揭示了黄海绿潮爆发时增生Ulva微繁殖体的早期扩散模式和微生态动态

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2025-12-01 Epub Date: 2025-09-03 DOI: 10.1016/j.hal.2025.102966

Runze Chen , Yinqing Zeng , Caihua Yao , Faqing He , Shulin Tan , Yutao Qin , Huanhong Ji , Lihua Xia , Lining Xia , Yuru Yan , Peimin He , Jianheng Zhang

Green tides caused by Ulva prolifera in the South Yellow Sea (SYS) pose significant ecological and economic threats. Neopyropia aquaculture rafts in the Subei Shoal are considered to be the main source of green tides in the SYS, where micropropagules are the ‘Seed Bank’ for green tides. But the early dynamics of the U. prolifera remain unclear due to the limitations of conventional monitoring methods. This study systematically investigated the spatiotemporal distribution characteristics and key environmental driving mechanisms of environmental DNA (eDNA) from U. prolifera in development areas of Yellow Sea green tide, using eDNA technology combined with environmental parameters. Surveys in April and June 2024 across Neopyropia raft-farming (RD transect) and non-raft (SY transect) areas revealed ecological differences during early green tide development. Key findings include:(1) In April, U. prolifera eDNA abundance in RD exhibited a "high near rafts, low farther away" distribution, regulated by temperature and total nitrogen, while SY followed similar trends driven primarily by temperature. No environmental factors were found to be significantly correlated with the distribution of U. prolifera eDNA in June. (2) High U. prolifera eDNA abundance at SY4 in April was driven by hydrodynamics (tidal asymmetry), temperature, and biological interactions (e.g., Cercozoa), identifying a hotspot for monitoring. (3) Raft-farming areas exhibited stronger species interactions, with Chlorophyta and Cercozoa closely linked to U. prolifera. The identification of Pirsonia sp. and other species provides a new perspective for elucidating the competitive mechanisms underlying early-stage U. prolifera outbreaks and for developing early biological control strategies against green tides. This study provides molecular ecological evidence for analyzing the aggregation driving mechanism of the development areas of early green tide in the SYS, highlights the utility of eDNA in monitoring, and offers theoretical support for marine ecosystem management under climate change.

南黄海由藻藻引起的绿潮对生态和经济造成了严重威胁。苏北浅滩的新异位养殖筏被认为是SYS绿潮的主要来源，其中微繁殖体是绿潮的“种子库”。但由于常规监测方法的限制，美国核扩散的早期动态仍不清楚。本研究采用eDNA技术结合环境参数，系统研究了黄海绿潮发育区多刺藻环境DNA （environmental DNA, eDNA）的时空分布特征及关键环境驱动机制。2024年4月和6月的调查显示，在绿潮形成早期，新冠藻木筏养殖区（RD样带）和非木筏养殖区（SY样带）存在生态差异。主要发现包括：(1)4月，黑龙江地区浒苔eDNA丰度表现出“近筏高，远筏低”的分布规律，受温度和总氮的调节，而黑龙江地区则主要受温度的影响。6月份，环境因子与浒苔eDNA的分布无显著相关。(2) 4月SY4区增殖U. U. prolifera eDNA丰度高，受水动力（潮汐不对称）、温度和生物相互作用（如尾虫）驱动，是监测热点。(3)筏养区物种间的相互作用较强，绿藻和尾藻与藻间的相互作用密切相关。Pirsonia sp.和其他物种的鉴定为阐明早期繁殖U.爆发的竞争机制和制定针对绿潮的早期生物控制策略提供了新的视角。本研究为分析南海早期绿潮发育区域聚集驱动机制提供了分子生态学证据，突出了eDNA在监测中的应用，为气候变化下的海洋生态系统管理提供了理论支持。

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引用次数: 0

Simplifying marine biotoxin data analysis: Advancing the Neuro-2a cell-based assay using R 简化海洋生物毒素数据分析：使用R推进基于神经2a细胞的测定

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2025-12-01 Epub Date: 2025-09-05 DOI: 10.1016/j.hal.2025.102968

Synne T. Frøstrup , Christian Ritz , Oliver Kappenstein , Astrid Spielmeyer , Christopher R. Loeffler

Marine biotoxins (MBs) pose a significant public health risk as seafood contaminants. Testing seafood for MBs before consumption can protect consumers and further provide quality assurances. The in vitro Neuro-2a (N2a) cell-based assay (CBA), is a sensitive, high-throughput, and cost-effective method for the semi-quantification of MBs such as ciguatoxins (CTXs) and brevetoxins (PbTxs), serving as an alternative to animal-based testing. However, the N2a CBA has not been validated, limiting its utility. High data variability based on several potential sources including inter-software inconsistencies, data transfer errors, and improper data processing (calculation errors), or handling (dealing with missing, corrupted, or inconsistent data), have been cited as major challenges to the method. Data errors or inaccuracies can disrupt data integrity and lead to false positive or negative results, with serious health implications. To address these issues, a customized R package, n2a, was developed as the first standardized and free data analysis operating procedure for the N2a CBA. It is designed for simultaneous dose-response analysis of assay derived data and displays parameter estimates, calculates effective concentration (EC₅₀), and generates high-quality graphical outputs. The n2a package ensures rapid dose-response model fitting for larger datasets (2 s per dataset) compared to traditional software (3 min per dataset), increasing data processing efficiency and reducing the potential for data handling errors.

海洋生物毒素作为海产品污染物，对公众健康构成重大威胁。在食用海产品前检测MBs，可以保护消费者，并进一步提供质量保证。体外基于神经2a （N2a）细胞的检测（CBA）是一种灵敏、高通量、经济高效的半定量方法，可作为动物实验的替代方法，用于卡卡毒素（CTXs）和短链毒素（PbTxs）等MBs。然而，N2a CBA尚未得到验证，限制了它的实用性。基于软件间不一致、数据传输错误和不当数据处理（计算错误）或处理（处理丢失、损坏或不一致的数据）等几个潜在来源的高数据可变性被认为是该方法面临的主要挑战。数据错误或不准确会破坏数据完整性，导致假阳性或假阴性结果，对健康造成严重影响。为了解决这些问题，开发了定制的R包n2a，作为n2a CBA的第一个标准化和免费的数据分析操作程序。它被设计用于同时剂量-反应分析测定数据和显示参数估计，计算有效浓度（EC50），并产生高质量的图形输出。与传统软件（每个数据集3分钟）相比，n2a包确保了更大数据集的快速剂量反应模型拟合（每个数据集2秒），提高了数据处理效率并减少了数据处理错误的可能性。

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引用次数: 0

Transcriptomic responses of toxic and non-toxic Microcystis aeruginosa to hydrogen peroxide and l-lysine treatments 有毒和无毒铜绿微囊藻对过氧化氢和赖氨酸处理的转录组反应

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2025-12-01 Epub Date: 2025-09-29 DOI: 10.1016/j.hal.2025.102992

Elizabeth K. Dahedl , Taylor L. Hancock , Hidetoshi Urakawa

Microcystis aeruginosa is a ubiquitous, toxic, bloom-forming cyanobacterium found in freshwater ecosystems worldwide. In this study, we assessed two algaecidal mitigation methods (hydrogen peroxide and l-lysine) for the treatment of two toxic and two non-toxic strains of M. aeruginosa. Whole-transcriptome analysis with total RNA sequencing was used to assess the modes of action of these algaecides. We found both treatments led to increased transcriptional activity for genes associated with sulfur and cysteine pathways, which both support antioxidant enzyme activity. These regulatory mechanisms along with methionine metabolism were more enhanced for l-lysine treated strains, and may demonstrate a lack of l-lysine regulatory mechanisms and potential impact to the biosynthesis of other amino acids as well as intracellular sulfur recycling processes seen in transcription results. Toxic and non-toxic strains displayed a differential regulatory response to reduce oxidative stress levels. Two toxic strains downregulated the expression of microcystin biosynthesis genes and increased the expression of genes encoding antioxidant enzymes. Our results provide further support for the view that microcystins do not offer protection against high levels of oxidative stress. Production of microcystin may interfere with antioxidant enzyme functionality, and additionally, sulfur and cysteine demands for antioxidant enzymes likely outcompete their use for microcystin production under oxidative stress conditions. These findings can aid in the mitigation of toxin-producing M. aeruginosa blooms, suggesting high-dose hydrogen peroxide application has the potential to lower bloom toxicity through fast-acting impairment to microcystin gene synthetase expression as well as other metabolic functioning, likely lowering intracellular microcystin content, which may be released upon cell lysis after treatments. To our knowledge, the expression of microcystin synthetase genes after exposure to l-lysine has never been examined before. Seeing as this is a safe algaecide specifically targeting M. aeruginosa, this was another beneficial finding.

铜绿微囊藻是一种普遍存在的有毒蓝藻，存在于世界各地的淡水生态系统中。在这项研究中，我们评估了两种杀藻缓解方法（双氧水和赖氨酸）对两种有毒和两种无毒M. aeruginosa菌株的治疗。使用全转录组分析和总RNA测序来评估这些杀藻剂的作用方式。我们发现两种处理方法都增加了硫和半胱氨酸途径相关基因的转录活性，这两种途径都支持抗氧化酶的活性。这些调节机制以及蛋氨酸代谢在l-赖氨酸处理菌株中得到了更强的增强，这可能表明缺乏l-赖氨酸调节机制，并可能影响转录结果中其他氨基酸的生物合成以及细胞内硫循环过程。有毒和无毒菌株对降低氧化应激水平表现出不同的调节反应。两株毒株微囊藻毒素合成基因表达下调，抗氧化酶编码基因表达上调。我们的研究结果进一步支持了微囊藻毒素不能抵抗高水平氧化应激的观点。微囊藻毒素的产生可能会干扰抗氧化酶的功能，此外，在氧化应激条件下，硫和半胱氨酸对抗氧化酶的需求可能会超过它们对微囊藻毒素产生的使用。这些发现有助于减轻产生毒素的M. aeruginosa华，表明高剂量过氧化氢应用有可能通过对微囊藻毒素基因合成酶表达的速效损伤以及其他代谢功能来降低华毒性，可能降低细胞内微囊藻毒素含量，这些含量可能在处理后细胞裂解时释放出来。据我们所知，暴露于l-赖氨酸后微囊藻毒素合成酶基因的表达从未被检测过。鉴于这是一种专门针对绿脓杆菌的安全杀藻剂，这是另一个有益的发现。

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引用次数: 0

Controlling harmful algal blooms (HABs) in marine waters: Review of current status and future prospects 海洋有害藻华的控制：现状与展望

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2025-12-01 Epub Date: 2025-10-31 DOI: 10.1016/j.hal.2025.102989

Donald M. Anderson , Mark L. Wells , Vera L. Trainer , Marc Suddleson , Kevin Claridge , Kathryn J. Coyne , Quay Dortch , Christopher J. Gobler , Cynthia A. Heil , Nobuharu Inaba , H. Dail Laughinghouse IV , Jorge I. Mardones , Natsuko Nakayama , Taegyu Park , Melissa B. Peacock , Kaytee Pokrzywinski , Heather Raymond , Jennifer H. Toyoda , Dean Trethewey , Petra M. Visser , Yongquan Yuan

The societal, economic, geographic, and environmental impacts from marine harmful algal blooms (HABs) have increased in many regions around the world. The growing array of impacts is large and varied, threatening human health, marine and freshwater wildlife, and ecosystems upon which many nations rely on for food, recreation, tourism, and a plethora of other goods and services. Although the HAB burden has grown substantially over the past few decades, marine and estuarine HAB control remains one of the least developed areas of HAB science. The disconnect between HAB control needs and solutions stems in part from public, stakeholder, and scientific uncertainties about the balance between benefits and potentially undesirable environmental consequences. Other more practical challenges can include substantial regulation of in situ testing, scaling up laboratory-proven technologies to attack widespread blooms that can move in three dimensions in open marine waters, and an immature commercial market. Here we describe the status of control strategies targeting marine coastal and estuarine HABs, in particular those few approaches that have been tested in mesocosm or field applications. We identify the regulatory support, targeted science, investments, and public outreach that will be needed to accelerate the availability of applications for controlling HABs in marine waters worldwide.

海洋有害藻华（HABs）对社会、经济、地理和环境的影响在世界许多地区都有所增加。越来越多的影响是巨大而多样的，威胁着人类健康、海洋和淡水野生动物以及许多国家赖以为生的食物、娱乐、旅游和大量其他商品和服务的生态系统。虽然在过去的几十年里，有害藻华的负担大大增加，但海洋和河口有害藻华的控制仍然是有害藻华科学最不发达的领域之一。有害藻华控制需求与解决方案之间的脱节，部分原因在于公众、利益相关者和科学界对效益与潜在不良环境后果之间的平衡存在不确定性。其他更实际的挑战可能包括对原位测试的实质性监管，扩大实验室验证的技术，以应对在开阔的海水中可以三维移动的广泛繁殖，以及不成熟的商业市场。在这里，我们描述了针对海洋沿海和河口赤潮的控制策略的现状，特别是那些已经在中生态或现场应用中进行了测试的少数方法。我们确定了监管方面的支持、有针对性的科学研究、投资和公众宣传，这些都是加快控制全球海水中有害藻华应用的必要条件。

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引用次数: 0

Application of a hydrodynamic model to long-term monitoring data: exploring transport pathways to identify the source of high toxicity populations of Dinophysis fortii in aquaculture sites in northern Japan 水动力学模型在长期监测数据中的应用：探索运输途径，以确定日本北部水产养殖场高毒性福尔蒂鱼种群的来源

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2025-12-01 Epub Date: 2025-09-09 DOI: 10.1016/j.hal.2025.102976

Akira Miyazono , Takanori Kuribayashi , Yasufumi Hada , Ken Asakura , Kazuma Kobayashi , Katsuhiko Mizuno , Wai Mun Lum , Sirje Sildever , Hiroshi Kuroda , Satoshi Nagai

Diarrhetic Shellfish Toxicity (DST) occurs in northern Japan, Hokkaido and Tohoku, and is rarely observed in the southwest. A recent study using cultured strains of Dinophysis fortii revealed that high toxicity (HT) strains exist in northern Japan, while low-toxicity (LT) strains are found in the southwest. In this study, we analyzed 40 years of DST and plankton monitoring data from Hokkaido, eight years from Akita Prefecture, 33 years of oceanographic data from the Sea of Japan off northern Hokkaido, and the results of an ocean model experiment. The relationship between the annual DST maximum value and the cell density of D. fortii maxima in Hokkaido suggests the presence of both HT and LT strains. Results from the particle tracking experiment showed that transport of offshore populations of D. fortii to the coast is a key factor in HT DST events. Oceanographic data support that high DST along the Sea of Japan coasts in northern Hokkaido occurs in years of strong influence of the subarctic water of the Sea of Japan (SWSOJ). In northwestern Japan (Akita Prefecture), HT DST events were detected in years with strong influence of the second and third components of the Tsushima Warm Current (TWC2, 3) transporting particles from the SWSOJ. These results led to the conclusion that i) HT strains of D. fortii are transported by the SWSOJ reaching Hokkaido via its extension and Akita via the TWC2, 3, and ii) LT strains are transported to northern Japan via the first component of the Tsushima Warm Current (TWC1).

腹泻性贝类中毒（DST）发生在日本北部、北海道和东北地区，在西南部很少观察到。最近的一项研究表明，日本北部存在高毒性（HT）菌株，而西南地区存在低毒性（LT）菌株。在这项研究中，我们分析了北海道40年的DST和浮游生物监测数据，秋田县8年的海洋数据，北海道北部日本海33年的海洋数据，以及海洋模式实验的结果。北海道地区的年DST最大值与细胞密度之间的关系表明，北海道地区存在HT和LT菌株。粒子跟踪实验结果表明，福氏夜蛾近海种群向海岸的迁移是高温DST事件的关键因素。海洋学资料支持北海道北部日本海沿岸高夏时制发生在日本海亚北极水（SWSOJ）强烈影响的年份。在日本西北部（秋田县），高温DST事件发生在对马暖流第二和第三分量（TWC2, 3）从西南海域输送粒子影响较强的年份。这些结果表明：1)福氏弓形虫HT菌株通过西南暖流延伸至北海道和秋田，通过TWC2、3传播；2)LT菌株通过对马暖流第一分量（TWC1）传播至日本北部。

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引用次数: 0

Non-target effects of a harmful algal bloom biocontrol technology (DinoSHIELD) in an in-situ mesocosm experiment 有害藻华生物防治技术（DinoSHIELD）的非靶效应

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2025-12-01 Epub Date: 2025-09-20 DOI: 10.1016/j.hal.2025.102984

Yanfei Wang , William C. Holland , Alexandria G. Hounshell , Alan Kennedy , Kaytee Pokrzywinski , Kathryn J. Coyne

Harmful algal blooms (HABs) of toxic dinoflagellates, including Karenia brevis, pose significant threats to marine organisms and human health worldwide. Previous research identified a naturally occurring algicidal bacterium, Shewanella sp. IRI-160, which secretes algicidal compounds that limit the growth of dinoflagellates. More recent research focused on the development of a HAB bio-control technology, now called DinoSHIELD, using alginate hydrogel to immobilize Shewanella sp. IRI-160. DinoSHIELD continuously releases bacteria-derived algicides that target dinoflagellate growth while limiting bacterial dispersion. In this study, an in-situ mesocosm experiment using natural microbial communities was conducted to assess the environmental impacts of DinoSHIELD. This study aimed to evaluate the effects of DinoSHIELD on water quality and on non-target microbial communities under non-HAB conditions. At an application rate effective at controlling the growth of K. brevis in laboratory cultures, DinoSHIELD had minimal effects on water quality within the mesocosms. There was no significant effect on overall photosynthetic biomass or the abundance of non-target microbial organisms during the 6-day mesocosm experiment. Although there was no significant change in microbial eukaryotic community structure, 18S rRNA gene sequencing analysis showed that DinoSHIELD significantly increased species richness in the treatment compared to controls. Importantly, analysis of total bacterial and Shewanella sp. IRI-160-specific cell densities showed limited release of bacteria from DinoSHIELD and no change in total bacterial densities. Overall, these results support the eventual use of DinoSHIELD as a biocontrol strategy for managing dinoflagellate HABs without negatively affecting natural microbial communities or the surrounding environment.

有害藻华（HABs）的有毒鞭毛藻，包括短卡雷氏菌（Karenia brevis），对海洋生物和人类健康构成重大威胁。先前的研究发现了一种天然存在的杀藻细菌，希瓦氏菌sp. i -160，它分泌的杀藻化合物限制了鞭毛藻的生长。最近的研究集中在开发一种有害藻华生物防治技术，现在称为DinoSHIELD，使用海藻酸盐水凝胶固定希瓦氏菌i -160。DinoSHIELD持续释放细菌衍生的杀藻剂，以鞭毛藻生长为目标，同时限制细菌的分散。本研究以天然微生物群落为研究对象，通过原位环境实验对DinoSHIELD的环境影响进行了评价。本研究旨在评价在非hab条件下，DinoSHIELD对水质和非目标微生物群落的影响。在实验室培养物中，在有效控制短梭菌生长的施用量下，DinoSHIELD对中生态系统内的水质影响最小。在6 d的中生态试验中，对总光合生物量和非目标微生物丰度无显著影响。虽然真核微生物群落结构没有明显变化，但18S rRNA基因测序分析显示，与对照组相比，DinoSHIELD处理显著增加了物种丰富度。重要的是，对总细菌和希瓦氏菌i -160特异性细胞密度的分析表明，从DinoSHIELD中释放的细菌有限，总细菌密度没有变化。总的来说，这些结果支持最终使用DinoSHIELD作为一种生物防治策略来管理甲藻有害藻华，而不会对天然微生物群落或周围环境产生负面影响。

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引用次数: 0

Ranking the cytotoxic potency of Ostreopsis cf. ovata, Ostreopsis cf. siamensis (O. sp. 9), and purified ovatoxins in human keratinocytes 对Ostreopsis cf. ovata, Ostreopsis cf. siamensis （O. sp. 9）和纯化的卵细胞毒素在人角质形成细胞中的细胞毒性进行排名

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2025-12-01 Epub Date: 2025-10-10 DOI: 10.1016/j.hal.2025.103000

Loïc Plessis , Korian Lhaute , Fabienne Hervé , Madeleine Thimann , Véronique Séchet , Liliane Carpentier , Ariana B. Moutinho , Tiago Simões , Ana Amorim , Kevin Henry , Jorge L.B. Neves , Léana Gorse , Margaux Paradis , Stéphanie Brédif , Philipp Hess , Damien Réveillon

Ovatoxins (OVTXs), a family of marine polyketides structurally similar to palytoxin (PLTX), are suspected to cause respiratory symptoms and skin irritation among coastal users during blooms of the dinoflagellate Ostreopsis cf. ovata. To investigate their role in cutaneous toxicity, crude extracts from six O. cf. ovata strains (OVTX(+) and OVTX(−)) and three O. cf. siamensis (O. sp. 9) strains (OVTX(−)), along with six purified OVTX analogs, were tested for cytotoxicity (MTT assay) and cell death phenotypes (microscopy) in human keratinocyte models. Interestingly, cytotoxicity was driven by OVTX content, while OVTX(−) extracts were, on average, 150-fold and >1000-fold less potent for O. cf. siamensis and O. cf. ovata, respectively. Nevertheless, the latter two induced PLTX-like cell death, suggesting the presence of unidentified PLTX-like toxins. Purified OVTXs exhibited sub-nanomolar cytotoxicity, 3.5- to 12.5-fold lower than PLTX (IC₅₀ = 0.036–0.642 nM vs. 0.011–0.049 nM), ranking in potency: PLTX > OVTX-d > OVTX-b > OVTX-a > OVTX-c > OVTX-e >>> OVTX-h (non-toxic, likely due to ring-opening). This study demonstrates the high toxic potency of OVTXs, close to that of PLTX, while providing a comprehensive cytotoxicity assessment of OVTX analogs, which could be useful for assessing the risks of human exposure.

卵泡毒素（OVTXs）是一种结构类似于palytoxin （PLTX）的海洋多酮类化合物，在鞭毛藻Ostreopsis cfv . ovata繁殖期间，被怀疑在沿海使用者中引起呼吸道症状和皮肤刺激。为了研究它们在皮肤毒性中的作用，在人角质细胞模型中，对6株O. cf. ovata菌株（OVTX（+）和OVTX(−)）和3株O. cf. siamensis （O. sp. 9）菌株（OVTX(−)）的粗提取物以及6种纯化的OVTX类似物进行了细胞毒性（MTT法）和细胞死亡表型（显微镜）检测。有趣的是，细胞毒性是由OVTX含量驱动的，而OVTX（−）提取物对O. cf. siamensis和O. cf. ovata的毒性分别平均低150倍和1000倍。然而，后两种药物诱导pltx样细胞死亡，表明存在未知的pltx样毒素。纯化的OVTXs具有亚纳米级的细胞毒性，比PLTX低3.5- 12.5倍（IC50 = 0.036-0.642 nM vs. 0.011-0.049 nM），效价顺序为：PLTX >； OVTX-d > OVTX-b > OVTX-a > OVTX-c > OVTX-e >>> > OVTX-h（无毒，可能是由于环打开）。本研究证明了OVTX的高毒性效力，接近PLTX，同时提供了OVTX类似物的全面细胞毒性评估，这可能有助于评估人类暴露的风险。

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引用次数: 0

A modeling investigation into the ecological role of mixotrophy in Karenia brevis blooms on the West Florida Shelf 混合营养在西佛罗里达陆架短卡兰氏菌华中生态作用的模拟研究

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2025-12-01 Epub Date: 2025-09-16 DOI: 10.1016/j.hal.2025.102979

Yuren Chen , Ming Li , Patricia M. Glibert , Cynthia Heil , So Hyun Ahn

While laboratory experiments show Karenia brevis graze on Synechococcus to supplement nutrition, the ecological role of mixotrophy in K. brevis blooms on the West Florida Shelf remains unquantified. This study employs a three-dimensional coupled hydrodynamic-biogeochemical model to investigate the contribution of mixotrophic feeding to the K. brevis growth as well as the role of mixotrophic grazing in suppressing prey population and delivering a competitive advantage to the mixotroph. It is shown that mixotrophy moderately increased the growth rate of K. brevis in the bloom center but was important along the offshore margin of the bloom region, where the prey-to-predator ratio was high. With the digestion rate reaching over 200 prey cells K. brevis^-1 day^-1, mixotrophy could support a heterotrophic growth rate of up to 0.16 day^-1 in the offshore region and may facilitate the offshore expansion of K. brevis blooms. Mixotrophic feeding also played a significant role in sustaining the K. brevis bloom during the late spring and summer periods when the inorganic nutrient concentrations were low. The grazing pressure exerted on Synechococcus was found to be vital for the slow-growing K. brevis to outcompete the oligotrophic-adapted prey. These model results demonstrate that mixotrophy not only functions as an additional nutrient source but also as an ecological mechanism that can reshape interspecific competition and harmful algal bloom dynamics.

虽然实验室实验表明短克雷氏菌以聚球菌为食补充营养，但西佛罗里达大陆架短克雷氏菌繁殖中混合营养的生态作用仍未量化。本研究采用三维水动力学-生物地球化学耦合模型，研究了混合营养化饲养对短叶虎生长的贡献，以及混合营养化放牧在抑制猎物数量和为混合营养化动物提供竞争优势中的作用。结果表明，混合营养适度地提高了短链乳杆菌在华区中心的生长速度，但在华区近海边缘的生长速度很重要，因为那里的捕食比很高。当消化速度超过200个猎物细胞-1 day-1时，混合营养可以在近海地区支持高达0.16 day-1的异养生长速率，并可能促进短叶藻华的近海扩张。在无机营养物浓度较低的春末夏季，混合营养化饲喂对短叶藻华的维持也起着重要作用。研究发现，对聚珠球菌施加的放牧压力对于生长缓慢的短链镰刀菌与适应寡养的猎物竞争至关重要。这些模型结果表明，混合营养不仅是一种额外的营养来源，而且是一种重塑种间竞争和有害藻华动态的生态机制。

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引用次数: 0

Sub-lethal effects of natural cyanobacterial blooms on fish: Enzymatic activity and swimming performance in Gasterosteus aculeatus 天然蓝藻华对鱼类的亚致死效应：鱼的酶活性和游泳性能

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2025-12-01 Epub Date: 2025-09-03 DOI: 10.1016/j.hal.2025.102965

Francesco Masnadi , Xuewei Qi , John M. Taylor , Joachim Sturve , Valentina Di Santo , Agnes M.L. Karlson

Cyanobacterial blooms are intensifying worldwide due to eutrophication and climate change, increasing cyanotoxin exposure to aquatic organisms. This study investigated the physiological, biochemical, and behavioural impacts of cyanobacterial blooms on the three-spined stickleback (Gasterosteus aculeatus), a widespread mesopredatory fish. Adult sticklebacks were exposed for two weeks to naturally collected bloom material dominated by toxic Nodularia spumigena, non-toxic Aphanizomenon sp., or a 50:50 mix. We measured toxin accumulation (NOD_eq), hepatic enzymatic activities (ethoxyresorufin-O-deethylase [EROD], glutathione S-transferases [GSTs], glutathione reductase [GR], and catalase [CAT]), and escape swimming performance (centre-of-mass velocity, angular velocity, distance, and duration) in a multiparametric endpoints approach. Sub-lethal toxin levels in muscle tissue ranged from 0.006 to 0.077 µg g⁻¹ d.w. Results showed that fish exposed to toxic-dominated treatments showed significantly elevated EROD activity (up to 200 % increase), moderate increases in GR and GSTs, and reduced CAT activity compared to controls. Notably, distance travelled during escape responses was reduced by ∼50 % in the high-toxicity treatment and showed an inverse correlation with EROD activity, suggesting a trade-off between detoxification effort and swimming performance. Overall, our results demonstrate that EROD is a sensitive biomarker for cyanotoxin exposure in fish under natural bloom conditions. This finding highlights the need to consider natural cyanotoxin effects when interpreting environmental assessments, particularly given the projected increase in bloom frequency and severity under future climate scenarios.

由于富营养化和气候变化，蓝藻华在世界范围内加剧，增加了对水生生物的蓝藻毒素暴露。本研究研究了蓝藻华对三棘棘鱼（一种广泛分布的中游鱼类）的生理、生化和行为影响。将成年棘鱼暴露于自然收集的以有毒的spumigena Nodularia，无毒的aphanizomensp或50:50混合为主的开花材料中两周。我们用多参数端点方法测量了毒素积累（NODeq）、肝脏酶活性（乙氧基间苯二酚-o -去甲基化酶[EROD]、谷胱甘肽s -转移酶[GSTs]、谷胱甘肽还原酶[GR]和过氧化氢酶[CAT]）和逃逸游泳性能（质心速度、角速度、距离和持续时间）。肌肉组织中的亚致死毒素水平从0.006µg到0.077µg不等。结果显示，与对照组相比，暴露于毒素为主处理的鱼的EROD活性显著升高（高达200%），GR和GSTs适度增加，CAT活性降低。值得注意的是，在高毒性处理中，在逃逸反应期间行进的距离减少了约50%，并且与EROD活性呈负相关，这表明在解毒努力和游泳表现之间存在权衡。总的来说，我们的研究结果表明EROD是一个敏感的生物标志物，在自然水华条件下，鱼类暴露于蓝藻毒素。这一发现强调了在解释环境评估时考虑天然蓝藻毒素影响的必要性，特别是考虑到在未来气候情景下预计的藻华频率和严重程度的增加。

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引用次数: 0