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 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 Understanding the Differences in the Growth and Toxin Production of Anatoxin-Producing Cuspidothrix issatschenkoi Cultured with Inorganic and Organic N Sources from a New Perspective: Carbon/Nitrogen Metabolic Balance

Toxins ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 724
Author(s):  
Siyi Tao ◽  
Suqin Wang ◽  
Lirong Song ◽  
Nanqin Gan
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Nitrogen Sources ◽  
Dry Weight ◽  
Toxin Production ◽  
Organic N ◽  
Control Group ◽  
Metabolic Balance ◽  
N Sources ◽  
Inorganic And Organic

Cyanotoxins are the underlying cause of the threat that globally pervasive Cyanobacteria Harmful algal blooms (CyanoHABs) pose to humans. Major attention has been focused on the cyanobacterial hepatotoxin microcystins (MCs); however, there is a dearth of studies on cyanobacterial neurotoxin anatoxins. In this study, we explored how an anatoxin-producing Cuspidothrix issatschenkoi strain responded to culture with inorganic and organic nitrogen sources in terms of growth and anatoxins production. The results of our study revealed that ʟ- alanine could greatly boost cell growth, and was associated with the highest cell productivity, while urea significantly stimulated anatoxin production with the maximum anatoxin yield reaching 25.86 μg/mg dry weight, which was 1.56-fold higher than that in the control group (BG11). To further understand whether the carbon/nitrogen balance in C. issatschenkoi would affect anatoxin production, we explored growth and toxin production in response to different carbon/nitrogen ratios (C/N). Anatoxin production was mildly promoted when the C/N ratio was within low range, and significantly inhibited when the C/N ratio was within high range, showing approximately a three-fold difference. Furthermore, the transcriptional profile revealed that anaC gene expression was significantly up-regulated over 2–24 h when the C/N ratio was increased, and was significantly down-regulated after 96 h. Overall, our results further enriched the evidence that urea can stimulate cyanotoxin production, and ʟ-alanine could boost C. issatschenkoi proliferation, thus providing information for better management of aquatic systems. Moreover, by focusing on the intracellular C/N metabolic balance, this study explained the anatoxin production dynamics in C. issatschenkoi in response to different N sources.

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 Is Occurrence of Harmful Algal Blooms in the Exclusive Economic Zone of India on the Rise?

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
K. B. Padmakumar ◽  
N. R. Menon ◽  
V. N. Sanjeevan
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Exclusive Economic Zone ◽  
Prorocentrum Lima ◽  
Clear Cut ◽  
The Past ◽  
Spatial Coverage ◽  
Indian Waters ◽  
Frequency Intensity

Occurrence, increase in frequency, intensity and spatial coverage of harmful algal blooms during the past decade in the EEZ of India are documented here. Eighty algal blooms were recorded during the period 1998–2010. Of the eighty algal blooms, 31 blooms were formed by dinoflagellates, 27 by cyanobacteria, and 18 by diatoms. Three raphidophyte and one haptophyte blooms were also observed. Potentially toxic microalgae recorded from the Indian waters were Alexandrium spp., Gymnodinium spp. Dinophysis spp., Coolia monotis, Prorocentrum lima, and Pseudo-nitzschia spp. Examination of available data from the literature during the last hundred years and in situ observations during 1998–2010 indicates clear-cut increase in the occurrence of HABs in the Indian EEZ.

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 Harmful algal blooms and climate change: Learning from the past and present to forecast the future

Harmful Algae ◽  
2015 ◽  
Vol 49 ◽  
pp. 68-93 ◽  
Author(s):  
Mark L. Wells ◽  
Vera L. Trainer ◽  
Theodore J. Smayda ◽  
Bengt S.O. Karlson ◽  
Charles G. Trick ◽  
...  
Keyword(s):  
Climate Change ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
The Past ◽  
The Future

Impacts of harmful algal blooms on marine aquaculture in a low-carbon future

Harmful Algae ◽  
2021 ◽  
Vol 110 ◽  
pp. 102143
Author(s):  
Manfred Lenzen ◽  
Mengyu Li ◽  
Shauna A. Murray
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Low Carbon ◽  
Marine Aquaculture

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 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.

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