scholarly journals Effects of Modified Clay on Phaeocystis globosa Growth and Colony Formation

2021 ◽  
Vol 18 (19) ◽  
pp. 10163
Author(s):  
Xiangzheng Ren ◽  
Zhiming Yu ◽  
Lixia Qiu ◽  
Xihua Cao ◽  
Xiuxian Song
Keyword(s):  
Colony Formation ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Cell Damage ◽  
Extracellular Polysaccharide ◽  
Inorganic Phosphorus ◽  
Colony Development ◽  
Stress Concentrations ◽  
Phaeocystis Globosa ◽  
Modified Clay

Phaeocystis globosa is a globally distributed harmful algal blooms (HABs) species dominated by the colonial morphotype, which presents dramatic environmental hazards and poses a threat to human health. Modified clay (MC) can effectively flocculate HAB organisms and prevent their subsequent growth, but the effects of MC on colony-dominated P. globosa blooms remain uncertain. In this paper, a series of removal and incubation experiments were conducted to investigate the growth, colony formation and colony development of P. globosa cells after treatment with MC. The results show that the density of colonies was higher at MC concentrations below 0.2 g/L compared to those in the control, indicating the role of P. globosa colonies in resistance to environmental stress. Concentrations of MC greater than 0.2 g/L could reduce the density of solitary cells and colonies, and the colony diameter and extracellular polysaccharide (EPS) content were also decreased. The adsorption of MC to dissolved inorganic phosphorus (DIP) and the cell damage caused by collision may be the main mechanisms underlying this phenomenon. These results elucidate that the treatment with an appropriate concentration of MC may provide an effective mitigation strategy for P. globosa blooms by preventing their growth and colony formation.

scholarly journals Removal effect of algicidal modified clay on Phaeocystis globosa blooms in culturing enclosure experiments: A short communication

2021 ◽  
Vol 869 (1) ◽  
pp. 012068
Author(s):  
X Qin ◽  
X Chen ◽  
F Li ◽  
H Ya ◽  
D Zhu ◽  
...  
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Control Group ◽  
Beibu Gulf ◽  
Blank Control Group ◽  
Phaeocystis Globosa ◽  
Marine Aquaculture ◽  
Modified Clay ◽  
The Past ◽  
Field Culture

Abstract With the increased scale of marine aquaculture in the Beibu Gulf, as well as accelerating urbanization and industrialization, frequent harmful algal blooms (HABs) have occurred in this area, especially those formed by Phaeocystis globosa in the past several years. As the P. globosa bloom has been a serious marine ecological disaster in the Beibu Gulf, research on quick and effective methods to eliminate P. globosa blooms is a hot research topic. In this study, the bacteria Streptomyces yatensis B4503 combined with modified diatomite was used to prepare algicidal modified clay, which was then used to study the removal effect on P. globosa blooms in field culture enclosures. The results showed that after 6 h of treatment with algicidal modified clay, compared with the blank control group, the cell density and chlorophyll a content of P. globosa decreased by 26.86% and 64.03%, respectively, and they decreased by 75.23% and 84.81%, respectively, after 24 h. The study indicated that algicidal modified clay can be applied to eliminate HABs caused by P. globosa in coastal water.

scholarly journals Bacterial Composition Associated With Giant Colonies of the Harmful Algal Species Phaeocystis globosa

2021 ◽  
Vol 12 ◽  
Author(s):  
Zhu Zhu ◽  
Rui Meng ◽  
Walker O. Smith Jr. ◽  
Hai Doan-Nhu ◽  
Lam Nguyen-Ngoc ◽  
...  
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Algal Species ◽  
Microbial Consortia ◽  
Colony Development ◽  
Microbial Composition ◽  
Phaeocystis Globosa ◽  
Ambient Seawater ◽  
Bacterial Composition ◽  
Bacterial Consortia

The cosmopolitan algae Phaeocystis globosa forms harmful algal blooms frequently in a number of tropical and subtropical coastal regions in the past two decades. During the bloom, the giant colony, which is formed by P. globosa, is the dominant morphotype. However, the microenvironment and the microbial composition in the intracolonial fluid are poorly understood. Here, we used high-throughput 16S rRNA amplicon sequencing to examine the bacterial composition and predicted functions in intracolonial fluid. Compared with the bacterial consortia in ambient seawater, intracolonial fluids possessed the lower levels of microbial richness and diversity, implying selectivity of bacteria by the unique intracolonial microenvironment enclosed within the P. globosa polysaccharide envelope. The bacterial consortia in intracolonial fluid were dominated by Balneola (48.6% of total abundance) and Labrezia (28.5%). The bacteria and microbial function enriched in intracolonial fluid were involved in aromatic benzenoid compounds degradation, DMSP and DMS production and consumption, and antibacterial compounds synthesis. We suggest that the P. globosa colonial envelope allows for the formation of a specific microenvironment; thus, the unique microbial consortia inhabiting intracolonial fluid has close interaction with P. globosa cells, which may benefit colony development.

scholarly journals The Antialgal Mechanism of Luteolin-7-O-Glucuronide on Phaeocystis globosa by Metabolomics Analysis

2019 ◽  
Vol 16 (17) ◽  
pp. 3222
Author(s):  
Jingyi Zhu ◽  
Yeyin Yang ◽  
Shunshan Duan ◽  
Dong Sun
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Tricarboxylic Acid Cycle ◽  
Tca Cycle ◽  
Tricarboxylic Acid ◽  
Phaeocystis Globosa ◽  
Acetyl Coa ◽  
Intracellular Metabolites ◽  
Extracellular Metabolites ◽  
Significant Difference

Antialgal compounds from plants have been identified as promising candidates for controlling harmful algal blooms (HABs). In our previous study, luteolin-7-O-glucuronide was used as a promising algistatic agent to control Phaeocystis globosa (P. globose) blooms; however, its antialgal mechanism on P. globosa have not yet been elaborated in detail. In this study, a liquid chromatography linked to tandem mass spectrometry (LC-MS/MS)-based untargeted metabolomic approach was used to investigate changes in intracellular and extracellular metabolites of P. globosa after exposure to luteolin-7-O-glucuronide. Significant differences in intracellular metabolites profiles were observed between treated and untreated groups; nevertheless, metabolic statuses for extracellular metabolites were similar among these two groups. For intracellular metabolites, 20 identified metabolites showed significant difference. The contents of luteolin, gallic acid, betaine and three fatty acids were increased, while the contents of α-Ketoglutarate and acetyl-CoA involved in tricarboxylic acid cycle, glutamate, and 11 organic acids were decreased. Changes in those metabolites may be induced by the antialgal compound in response to stress. The results revealed that luteolin played a vital role in the antialgal mechanism of luteolin-7-O-glucuronide on P. globosa, because luteolin increased the most in the treatment groups and had strong antialgal activity on P. globosa. α-Ketoglutarate and acetyl-CoA were the most inhibited metabolites, indicating that the antialgal compound inhibited the growth through disturbed the tricarboxylic acid (TCA) cycle of algal cells. To summarize, our data provides insights into the antialgal mechanism of luteolin-7-O-glucuronide on P. globosa, which can be used to further control P. globosa blooms.

scholarly journals Effects of Mixed Allelochemicals on the Growth of Microcystis aeruginosa, Microcystin Production, Extracellular Polymeric Substances, and Water Quality

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1861
Author(s):  
Ping Ouyang ◽  
Chao Wang ◽  
Peifang Wang ◽  
Xiaorong Gan ◽  
Xun Wang ◽  
...  
Keyword(s):  
Ethyl Acetate ◽  
Malonic Acid ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Extracellular Polymeric Substances ◽  
Algal Growth ◽  
Sharp Decrease ◽  
Inorganic Phosphorus ◽  
Nonanoic Acid ◽  
Control Group

The inhibition of cyanobacteria growth by allelochemicals, which controls harmful algal blooms has been examined in many studies. The objective of this work was to compare the efficiencies of different allelochemicals and determine a mixing proportion corresponding to the highest algae inhibiting activity and smallest adverse effect. The obtained results demonstrated that artemisinin, nonanoic acid, malonic acid, and ethyl acetate inhibited algal growth more efficiently than D-menthol and lactic acid. Synergies were observed in five groups of allelochemical combinations with inhibition ratios exceeding 80%, and the concentrations of extracellular microcystin-LR in the groups with high algal inhibition ratios were lower than that in the control group on the 7th day. No changes in extracellular polymeric substances compositions were detected after treatment. The permanganate indices of the treated groups were higher than that of the control group; however, this disparity gradually decreased with time. In addition, a sharp decrease in the concentration of dissolved inorganic phosphorus was observed for all treated groups. From the obtained data, the optimal proportion of mixed allelochemicals corresponding to 3.94 mg L−1 of artemisinin, 6.27 mg L−1 of nonanoic acid, 8.2 mg L−1 of malonic acid, and 6.38 mg L−1 of ethyl acetate was suggested.

scholarly journals Growth Inhibition of Phaeocystis Globosa Induced by Luteolin-7-O-glucuronide from Seagrass Enhalus acoroides

2019 ◽  
Vol 16 (14) ◽  
pp. 2615 ◽  
Author(s):  
Jingyi Zhu ◽  
Han Xiao ◽  
Qi Chen ◽  
Min Zhao ◽  
Dong Sun ◽  
...  
Keyword(s):  
Aqueous Extract ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
High Resolution Mass Spectrometry ◽  
Chemical Constituents ◽  
Common Species ◽  
Phaeocystis Globosa ◽  
Seagrass Meadows ◽  
Enhalus Acoroides ◽  
Major Chemical

Enhalus acoroides (E. acoroides) is one of the most common species in seagrass meadows. Based on the application of allelochemicals from aquatic plants to inhibit harmful algal blooms (HABs), we used E. acoroides aqueous extract against harmful algae species Phaeocystis globosa (P. globosa). The results showed that E. acoroides aqueous extract could significantly inhibited the growth of P. globosa, decrease the chlorophyll-a content and photosynthetic efficiency (Fv/Fm) values of P. globosa, followed by vacuolization, plasmolysis, and the destruction of organelles. Twelve types of major chemical constituents were identified in E. acoroides aqueous extracts by ultraperformance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS), including six flavonoids, two homocyclic peptides, two long-chain aliphatic amides, one tannin, and one nitrogen heterocyclic compound. Flavonoids were the characteristic chemical constituents of E. acoroides aqueous extract. Furthermore, the antialgal activity of luteolin-7-O-glucuronide (68.125 μg/mL in 8 g/L E. acoroides aqueous extract) was assessed. The EC50–96 h value was 34.29 μg/mL. In conclusion, the results revealed that luteolin 7-O-glucuronide was one of the antialgal compounds of E. acoroides aqueous extract, with potential application as novel algaecide.

scholarly journals Effect of Modified Clay on the Growth Dynamics and Physio—Biochemical Response of Newly Hatched Larvae of the Marine Medaka (Oryzias melastigma)

2021 ◽  
Vol 9 (8) ◽  
pp. 822
Author(s):  
Peipei Zhang ◽  
Xiuxian Song ◽  
Yue Zhang ◽  
Huihui Shen ◽  
Xueyi Dong ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Aluminum Content ◽  
Field Application ◽  
Effective Dosage ◽  
Sod Activity ◽  
Marine Medaka ◽  
Modified Clay ◽  
Oryzias Melastigma

An outbreak of harmful algal blooms (HABs) often leads to the death of fish and other marine organisms and causes serious losses to human economic activities. Modified clay (MC) technology is an effective way to control HABs. Although the material and preparation process are based on the premise of green and safety, the potential eco-environmental impacts of MC on non-target organisms should still have to receive attention before field applications can occur. Therefore, the effects of one commonly used modified clay, polyaluminum chloride-modified clay (PAC-MC), on the survival, growth, and oxidative stress of the marine medaka (Oryzias melastigma) were studied. The toxicity test results showed that the 96-h median lethal concentration (96-h LC50) of PAC-MC for newly hatched medaka larvae was 5.204 g/L, which was much higher than the concentration used on site (4–10 t/km2). Within the concentration range of PAC-MC used in this experiment (≤2 g/L), the morphology, heart rate, growth, and aluminum content of larvae did not change with the increase in the modified clay concentration. Low concentrations of PAC-MC (≤0.5 g/L) did not significantly affect catalase (CAT) activity, superoxide dismutase (SOD) activity, peroxidase (POD) activity, and the content of malondialdehyde (MDA), but higher concentrations of PAC-MC (such as 2 g/L) caused oxidative damage to the larvae and increased the antioxidant enzyme activity of the larvae. The present study revealed that under an effective dosage for treating harmful algal blooms on site, PAC-MC had no adverse effects on the survival, growth, oxidative stress, and aluminum content of the newly hatched marine medaka, which provides a scientific basis for the field application of modified clay.

scholarly journals A Novel Algicidal Bacterium, Microbulbifer sp. YX04, Triggered Oxidative Damage and Autophagic Cell Death in Phaeocystis globosa , Which Causes Harmful Algal Blooms

2022 ◽  
Author(s):  
Xiaoying Zhu ◽  
Shuangshuang Chen ◽  
Guiying Luo ◽  
Wei Zheng ◽  
Yun Tian ◽  
...  
Keyword(s):  
Cell Death ◽  
Oxidative Damage ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Algal Bloom ◽  
Harmful Algal Bloom ◽  
Health Hazard ◽  
Autophagic Cell Death ◽  
Phaeocystis Globosa ◽  
Algicidal Bacterium

P. globosa is one of the most notorious harmful algal bloom (HAB)-causing species, which can secrete hemolytic toxins, frequently cause serious ecological pollution, and pose a health hazard to animals and humans. Hence, screening for bacteria with high algicidal activity against P. globosa and studies on the algicidal characteristics and mechanism will contribute to providing an ecofriendly microorganism-controlling agent for preventing the occurrence of algal blooms and reducing the harm of algal blooms to the environment.

scholarly journals Zooming in on dynamics of marine microbial communities in the phycosphere of Akashiwo sanguinea (Dinophyta) blooms

2020 ◽  
Author(s):  
Seung Won Jung ◽  
Joonsang Park ◽  
Junsoo Kang ◽  
Hyun-Jung Kim ◽  
Hyung Min Joo ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Microbial Communities ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Close Association ◽  
Time Lag ◽  
Inorganic Phosphorus ◽  
Dna Viruses ◽  
Akashiwo Sanguinea ◽  
Nucleocytoplasmic Large Dna Viruses

Abstract Background: Characterising ecological relationships between viruses, bacteria, and phytoplankton in the ocean are critical to understanding the ecosystem, yet these relationships are infrequently investigated together. To understand the dynamics of microbial communities and environmental factors in harmful algal blooms (HABs), we examined the environmental factors and microbial communities during Akashiwo sanguinea HABs in the Jangmok coastal waters of South Korea by metagenomics. Results: Specific bacterial communities showed synergistic and antagonistic relationships with A. sanguinea bloom. Endoparasitic dinoflagellate Amoebophrya sp. 1 controlled the bloom dynamics, as an increase in their abundance was correlated with HAB decline. In the nucleocytoplasmic large DNA viruses, abundance of Pandoraviridae increased following an increase in HAB. Operational taxonomic units and environmental factors associated with A. sanguinea were also visualized by network analysis: A. sanguinea-Amoebophrya sp. 1 (r=0.81, Time-lag: 2 day) and A. sanguinea-Pandoravirus dulcis (0.64, 0 day) relationships showed close association. A. sanguinea-dissolved organic carbon and -dissolved inorganic phosphorus relationships were also very closely correlated (each 0 day time-lag, respectively). Conclusions: Microbial communities and the environment dynamically and complexly changed in A. sanguinea bloom, and a rapid turnover of microorganisms could respond to ecological interactions. A. sanguinea bloom dramatically changes the environments through their exudation of dissolved carbohydrates by autotrophic processes, followed by changes in microbial communities involving host-specific viruses, bacteria, and parasitoids. Thus, microbial communities in HAB ecology are composed of various organisms and they interact in a complex way. Therefore, to interpret their ecosystem, the complex reactions among various microorganisms should be studied rather than studying a simple 1:1 reaction, such as a prey-predator interaction.

Using PAC-modified clays to control black-bloom-induced black suspended matter in Lake Taihu: deposition and resuspension of black matter/clay flocs

2015 ◽  
Vol 16 (1) ◽  
pp. 180-185
Author(s):  
Yawen Huang ◽  
Yong Pang ◽  
Guoxiang Wang ◽  
Ruiming Han ◽  
Jianjian Wang ◽  
...  
Keyword(s):  
Quartz Sand ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Lake Taihu ◽  
Subsequent Treatment ◽  
Bed Shear Stress ◽  
Polyaluminum Chloride ◽  
Modified Clay ◽  
Modified Clays ◽  
The Impact

Flocculation using modified clays is a technique widely applied in the management of harmful algal blooms (HABs). Polyaluminum chloride (PAC) modified clay is an efficient flocculating agent in HAB control; however its effectiveness in black bloom management is still largely unknown. In the present study, PAC-modified clay was used to flocculate a black bloom under simulated flows. The deposition and resuspension of the black matter/clay flocs and the impact of the spreading of quartz sand to the flocs were quantitatively studied. The results showed that a dosage of 1.8 g/L PAC-modified clay (0.8 g/L PAC and 1 g/L diatomite) could reduce turbidity by more than 90% in 1 h. The resuspension of flocs could be generated by a threshold bed shear stress of 0.045 N/m2. The addition of quartz sand inhibited the resuspension of flocs. We suggest that quartz sand can be used to effectively inhibit floc resuspension caused by waves and flow currents as the subsequent treatment of black bloom flocculation in Lake Taihu.

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