WATER RESEARCH
·
2025
·
IF 12.4
Xinyu Li,Cui Zeng,Xiurong Han,Liqiang Fan,Jing Zhao,Yingzhe Wang,Xiulin Wang,Keqiang Li
Multitudinous dissolved organic nitrogen (DON) enters seawater from Ulva prolifera green tides impacting phytoplankton community structure in the Yellow Sea. Field investigations and cultural experiments on U. prolifera -derived DON aging revealed its regulatory effects. The green-tide outbreak area of the Southern Yellow Sea exhibits a seasonal cycle where dominance shifts from diatoms to dinoflagellates effected by young to aging U. prolifera -derived DON from summer to spring. Diatom abundance rose significantly following the summer green tide outbreak, fueled by young, protein-rich DON released by U. prolifera . After autumn and winter aging, U. prolifera -derived DON was dominant from protein-like to humic-like components, and dinoflagellates bloomed in the green tide outbreak area. An aging U. prolifera -derived DON adding culture experiment of Chaetoceros curvisetus and Prorocentrum minimum proved that old and young DON promoted dinoflagellate and diatom growth, respectively. Diatoms preferred 0 and 12 days-aged DON (DON 0 and DON 12 ) with tyrosine B and tryptophan T components, whereas dinoflagellate favored 80 days-aged DON (DON 80 ) with humic acid E and UV fulvic acid A components. DON 0 and DON 12 can be absorbed by diatoms with higher uptake ( k up ) and growth ( k G ) constants than by dinoflagellates under low leucine aminopeptidase (LAP) conditions. Dinoflagellates absorb old DON with higher k up and k G values under higher LAP concentrations than diatoms. This was consistent with the loop of U. prolifera -derived DON turning over the seasonal succession of diatom dinoflagellates in the green-tide outbreak area. This study revealed mechanism of seasonal dinoflagellate- U. prolifera -diatom cycle, and provided new insights for impacts of U. prolifera green tides on phytoplankton regime shift, thus, acting as a basis for marine management strategies.
研究领域:
海洋生物学
·
生态学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
·
2024
·Vol. 129
·期 10
·e2024JC021373
·
IF 3.3
Kan Chen,Rui Yang,Min Li,Yanan Chen,Xiurong Han,Jing Zhao,Keqiang Li,Xiulin Wang
Human-induced dissolved organic nitrogen (DON) input is impacting coastal ecosystems globally, and the shift from diatoms to dinoflagellates may be associated with increasing DON concentrations and changing DON compositions. Based on field microcosm experiments, changes in three-dimensional fluorescence component and extracellular leucine aminopeptidase activity were used to reveal the effects of DON on diatom and dinoflagellate growth. Additionally, a Nutrients–bi-Phytoplankton–Detritus biogeochemical model was employed to elucidate the kinetic mechanism of DON on the shift from diatoms to dinoflagellates in the Bohai Sea (BS). Our results revealed that shifting diatom–dinoflagellate dominance was associated with the hydrophobic component of terrestrial DON. Dinoflagellates (i.e., Karenia mikimotoi ) efficiently assimilated humic-like substances in hydrophobic DON; whereas, diatoms (i.e., Chaetoceros spp.) efficiently utilized the protein-like components in hydrophilic DON. The reason for this was the higher extracellular leucine aminopeptidase activity of dinoflagellates compared to that of diatoms, which enabled them to degrade humic-like substances and protein-like components more effectively. The modeling study clarified that the DON composition, particularly the proportion of hydrophobic DON, regulated the shift from diatoms to dinoflagellates. Our study provides insight into the mechanisms underlying phytoplankton regime shifts in the BS and valuable guidance for decreasing eutrophication by controlling terrestrial DON inputs and compositions. Key Points Karenia mikimotoi can efficiently assimilate humic-like substances Chaetoceros spp. can efficiently utilize protein-like components Karenia mikimotoi has higher extracellular leucine aminopeptidase activity than Chaetoceros spp. Plain Language Summary Human-induced nitrogen input is causing major changes in coastal ecosystems worldwide and posing a threat to human well-being. In the Bohai Sea (BS), the increase in DON concentrations and changes in its composition have been linked to harmful algal blooms and a shift from diatom to dinoflagellate dominance. This study investigated the mechanism behind the shift from diatoms to dinoflagellates using field experiments, a biogeochemical model, and techniques for analyzing organic chemicals. Our findings indicated that dinoflagellates (represented by Karenia mikimotoi ) can efficiently assimilate humic-like substances in hydrophobic DON, and that diatoms (represented by Chaetoceros spp.) can effectively utilize protein-like components in hydrophilic DON. This difference arose because of higher extracellular leucine aminopeptidase activity in dinoflagellates compared to diatoms, enabling them to degrade humic-like substances and protein-like components more effectively. Our modeling study further revealed that the DON composition, particularly the proportion of hydrophobic DON, regulated the shift from diatoms to dinoflagellates. These insights into the mechanisms driving phytoplankton regime shifts in the BS provide valuable guidance for mitigating eutrophication by controlling terrestrial DON inputs and compositions.
研究领域:
海洋生态学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
HARMFUL ALGAE
·
2024
·
IF 5.5
Xihua Cao,Mingjiao Wang,Fan Liu,Xiuxian Song,Zhiming Yu
Single source with series modifications (SSSM) is a new method to modify clay surfaces by activating clay mineral resources for harmful algal blooms control. In this study, the optimal preparation conditions for this method were obtained using response surface methodology. Based on the material analysis, an important way to obtain modified clay (MC) with the excellent Prorocentrum donghaiense removal performance was explored and the optimum preparation conditions were as follows: calcination temperature 750 °C, alkali neutralization pH 3.7 and clay supplementation ratio 1.3:1. Under these conditions, the calcination treatment can effectively activate the aluminum element in the clay lattice and obtain the largest amount of highly active Al IV and Al V , which are readily released from the lattice as activated aluminum. When the alkali neutralization pH was adjusted to 3.7, the activated aluminum was hydrolyzed and induced into highly positively charged polyhydroxyaluminum compounds. The supplemented kaolin increased the yield of the MC product by surface convergence of the activated aluminum in the system. As a result, the optimized MC can form large particle size flocs with good regeneration and stability during the algal removal process, which greatly improved its ability to coagulate and sediment algal cells. Overall, the MC prepared by the SSSM method achieved high algal removal efficiency through targeted element activation and functional group shaping.
研究领域:
环境科学
·
海洋生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2025
·
IF 8
Xiaoer Wu,Ying Yang,Shuang Xie,Ping Zhong,Ning Xu
Harmful algal blooms formed by the mixotrophic dinoflagellate Akashiwo sanguinea are toxic to multiple aquatic organisms, although the relationship between toxicity and grazing is unknown. In this study, the effects of irradiance and nutrient levels on the grazing rate of A. sanguinea on the cryptophyte Rhodomonas salina were investigated using an optimized stable isotope method. Under light-limited conditions (0–30 μmol photons m −2 s −1 ), A. sanguinea exhibited higher hemolytic activity and grazing rate. Under the same level of irradiance, the growth and respiration rates were higher in co-culture treatments, while the oxygen release rate was higher in monoculture treatments. The growth rate, hemolytic activity, and grazing rate of A. sanguinea increased significantly with higher nutrient levels or an unbalanced N:P ratio. The hemolytic activity and grazing rate were higher in urea treatment, while the growth rate was higher in ammonia treatment. This study suggests that toxicity is involved in the feeding process of the mixotrophic dinoflagellate A. sanguinea ; the unique feeding flexibility adapting to low irradiance, increased nutrients, unbalanced N:P ratio, and organic nitrogen urea gains an advantage in interspecific competition among phytoplankton.
研究领域:
海洋生物学
·
生态毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2024
·
IF 8.1
Bin Li,Jianghong Shi,Xueling Xiang,Mengtao Zhang,Hui Ge,Shuhan Sun
Bromophenols has been proven to synthesize hydroxylated polybrominated diphenyl ethers (OH-PBDEs), which may pose additional environmental and health risks in the process of bioremediation. In this study, the removal of 2,4-dibromophenol (2,4-DBP) and 2,4,6-tribromophenol (2,4,6-TBP) and the biosynthetic of OH-PBDEs by Prorocentrum donghaiense were explored. The removal efficiencies of 2,4-DBP and 2,4,6-TBP ranged from 32.71% to 76.89% and 31.15%–78.12%, respectively. Low concentrations of 2,4-DBP stimulated algal growth , while high concentrations were inhibitory. Furthermore, exposure to 10.00 mg L −1 2,4-DBP resulted in the detection of 2′-hydroxy-2,3′,4,5′-tetrabromodiphenyl ether (2′–OH–BDE-68) within P . donghaiense . In contrast, increasing concentrations of 2,4,6-TBP considerably inhibited P . donghaiense growth, with 4′-hydroxy-2,3′,4,5′,6-pentabromodiphenyl ether (4′–OH–BDE-121) detected within P. donghaiense under 5.00 mg L −1 2,4,6-TBP. Metabolomic analysis further revealed that the synthesized OH-PBDEs exhibited higher toxicity than their precursors and identified the oxidative coupling as a key biosynthetic mechanism. These findings confirm the capacity of P. donghaiense to remove bromophenols and biosynthesize OH-PBDEs from bromophenols, offering valuable insights into formulating algal bioremediation to mitigate bromophenol contamination.
研究领域:
环境科学
·
海洋生物学
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PLANT CELL AND ENVIRONMENT
·
2024
·
IF 6
Huige Guo,Xiaochen Wang,Changlin Li,Hala F. Mohamed,Dawei Li,Lianghui Wang,Hongzhe Chen,Kunning Lin,Shuyuan Huang,Jinling Pang,Yuanbiao Zhang,Bernd Krock,Zhaohe Luo
Prevalent interactions among marine phytoplankton triggered by long-range climatic stressors are well-known environmental disturbers of community structure. Dynamic response of phytoplankton physiology is likely to come from interspecies interactions rather than direct climatic effect on single species. However, studies on enigmatic interactions among interspecies, which are induced by bioactive extracellular compounds (BECs), especially between related harmful algae sharing similar shellfish toxins, are scarce. Here, we investigated how BECs provoke the interactions between two notorious algae, Alexandrium minutum and Gymnodinium catenatum , which have similar paralytic shellfish toxin (PST) profiles. Using techniques including electron microscopy and transcriptome analysis, marked disruptions in G. catenatum intracellular microenvironment were observed under BECs pressure, encompassing thylakoid membrane deformations, pyrenoid matrix shrinkage and starch sheaths disappearance. In addition, the upregulation of gene clusters responsible for photosystem-I Lhca1/4 and Rubisco were determined, leading to weaken photon captures and CO 2 assimilation. The redistribution of lipids and proteins occurred at the subcellular level based on in situ focal plane array FTIR imaging approved the damages. Our findings illuminated an intense but underestimated interspecies interaction triggered by BECs, which is responsible for dysregulating photosynthesis and organelle function in inferior algae and may potentially account for fitness alteration in phytoplankton community.
研究领域:
海洋生物学
·
环境科学
·
分子生态学
✓ 已验证
DOI
高影响因子
MARINE POLLUTION BULLETIN
·
2022
·
IF 7.001
Kokoette Effiong,Jing Hu,Caicai Xu,Yiyi Zhang,Shumiao Yu,Tao Tang,Yuzhou Huang,Yongliang Lu,Wei Li,Jiangning Zeng,Xi Xiao
Harmful algal blooms (HABs) have induced severe damage worldwide. A novel high-efficient antialgal natural chemical, 3-indoleacrylic acid (3-IDC) with a 5-day half-maximal inhibitory concentration (IC 50, 5d ), was discovered from canola straw, and its algal inhibition mechanism was investigated. Adverse effects were observed on the growth of P. donghaiense with 3-IDC addition, following an increase in reactive oxygen species (ROS) production. 3-IDC also hindered the photosynthetic mechanism of P. donghaiense cells. Transcriptional results showed 3-IDC inhibiting the functions of all the nutrient assimilating genes, down-regulated ribulose-1,5-bisphosphate carboxylase/oxygenase II, and cytochrome f genes. The expression of heat shock protein ( HSP ) 70 and 90 and rhodopsin genes were also suppressed. The binding affinity of investigated receptors was observed. The conformational changes induced by the spatial microstructural alteration through 3-IDC may further contribute to the perturbation of those enzyme catalytic activities. The present results provide new insights on controlling HABs using 3-IDC.
研究领域:
环境科学
·
海洋生物学
·
植物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Zhongshi Wang,Zhiming Yu,Liyan He,Jianan Zhu,Lidong Liu,Xiuxian Song
Electrophysiology studies the electrical properties of cells and tissues including bioelectrical signals and membrane ion channel activities. As an important means to reveal ion channel related physiological functions and the underlying mechanisms, electrophysiological techniques have been widely used in studies of animals, higher plants and algae that are closely related to higher plants. However, few electrophysiological studies have been carried out in red tide organisms, especially in dinoflagellates, which is mainly due to the complex surface structure of dinoflagellate amphiesma. In this study, the surface amphiesma of Alexandrium pacificum , a typical red tide species, was removed by centrifugation, low-temperature treatment and enzymatic treatment. In all three treatments, low-temperature treatment with 4 °C for 2 h had high ecdysis rate and high fixation rate, and the treated cells were easy to puncture, so low-temperature treatment was used as a preprocessing treatment for subsequent current recording. Acquired protoplasts of A. pacificum were identified by calcofluor fluorescence and immobilized by poly-lysine. A modified “puncture” single-electrode voltage-clamp recording was first applied to dinoflagellates, and voltage-gated currents, which had the characteristics of outward K + current and inward Cl − current, were recorded and confirmed by ion replacement, indicating the voltage-gated currents were mixed. This method can be used as a technical basis for the electrophysiological study of dinoflagellates and provides a new perspective for the study of stress tolerance, red tide succession, and the regulation of physiological function of dinoflagellates.
研究领域:
海洋生物学
·
电生理学
·
细胞生物学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
MICROBIAL ECOLOGY
·
2025
·Vol. 88
·期 1
·1-16
·
IF 4
Su Jinzhu,Su YuPing,weng Yuxin,Ayub Gohar,She Chenxing,Xiao Yumei
Glyphosate-based herbicides are among the most widely used agricultural chemicals globally, and their widespread application presents risks to environmental health and aquatic ecosystems. Continuous glyphosate inputs disrupt phytoplankton communities, potentially triggering harmful algal blooms. This study examines the proliferation of microalgal species exposed to low glyphosate concentrations (0.05 mg/L) and various phosphorus sources, with a particular focus on C-P and C-O-P bond phosphonates, which have been insufficiently studied in previous research. We hypothesized that cyanobacteria might exhibit a competitive growth advantage over other algal species when exposed to C-P bond glyphosate, especially under phosphorus-limited conditions. In monoculture experiments, Microcystis aeruginosa and Peridinium umbonatum var. inaequale significantly increased their biomass when cultured with C-P bond phosphonates, whereas Scenedesmus bijuga failed to thrive under similar conditions. Peridinium umbonatum var. inaequale also displayed increased soluble protein content in response to glyphosate stress, indicating an adaptive stress response. In co-culture experiments, M. aeruginosa demonstrated greater tolerance to glyphosate than P. umbonatum var . inaequale , though biomass increases were not significantly correlated with soluble protein or APA. Sediment–water interface experiments revealed that glyphosate exposure significantly promoted cyanobacterial biomass, which was approximately five times greater than that of the inorganic phosphorus group. Notably, when cyanobacterial biomass exceeded 20% of the total, Cyanophyta replaced Chlorophyta as the dominant group, suggesting a potential competitive advantage under low-dose glyphosate exposure. These findings highlight that glyphosate may promote cyanobacterial dominance by altering phytoplankton community composition, potentially contributing to the increased frequency of harmful algal blooms in nutrient-limited aquatic environments.
研究领域:
环境毒理学
·
水生生态学
·
藻类学
·
生态毒理学
·
水污染
·
微生物生态学
·
生物地球化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）