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 Cyanopeptides Restriction and Degradation Co-mediate Microbiota Assembly During a Freshwater Cyanobacterial Harmful Algal Bloom (CyanoHAB)

2022 ◽  
Author(s):  
Han Gao ◽  
Ze Zhao ◽  
Lu Zhang ◽  
Feng Ju
Keyword(s):  
Community Assembly ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Algal Bloom ◽  
Lake Taihu ◽  
Harmful Algal Bloom ◽  
Size Fraction ◽  
Freshwater Ecosystems ◽  
Cyanobacterial Harmful Algal Blooms ◽  
Microbiota Diversity

Cyanobacterial harmful algal blooms (CyanoHABs) are globally intensifying and exacerbated by climate change and eutrophication. However, microbiota assembly mechanisms underlying CyanoHABs remain scenario specific and elusive. Especially, cyanopeptides, as a group of bioactive secondary metabolites of cyanobacteria, could affect microbiota assembly and ecosystem function. Here, the trajectory of cyanopeptides were followed and linked to microbiota during Microcystis-dominated CyanoHABs in lake Taihu, China. The most abundant cyanopeptide classes detected included microginin, spumigin, microcystin, nodularin and cyanopeptolin with total MC-LR-equivalent concentrations between 0.23 and 2051.54 ppb, of which cyanotoxins beyond microcystins (e.g., cyanostatin B and nodularin_R etc.) far exceeded reported organismal IC50 and negatively correlated with microbiota diversity, exerting potential collective eco-toxicities stronger than microcystins alone. The microbial communities were differentiated by size fraction and sampling date throughout CyanoHABs, and surprisingly, their variances were better explained by cyanopeptides (19-38%) than nutrients (0-16%). Cyanopeptides restriction (e.g., inhibition) and degradation are first quantitatively verified as the deterministic drivers governing community assembly, with stochastic processes being mediated by interplay between cyanopeptide dynamics and lake microbiota. This study presents an emerging paradigm in which cyanopeptides restriction and degradation co-mediate lake water microbiota assembly, unveiling new insights about the ecotoxicological significance of CyanoHABs to freshwater ecosystems.

Resource fluctuation patterns influence emergent properties of phytoplankton assemblages and their resistance to harmful algal blooms

2020 ◽  
Vol 71 (1) ◽  
pp. 56 ◽  
Author(s):  
Daniel L. Roelke ◽  
Sierra E. Cagle ◽  
Rika M.W. Muhl ◽  
Athanasia Sakavara ◽  
George Tsirtsis
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Life History Traits ◽  
Algal Bloom ◽  
Harmful Algal Bloom ◽  
Emergent Properties ◽  
Resource Exploitation ◽  
Stable States ◽  
Phytoplankton Assemblages ◽  
High Degree

Recent advances in phytoplankton modelling have used species-rich, self-organising assemblages. These models have shown that phytoplankton with complementary life-history traits related to resource exploitation assemble into stable states of lumpy coexistence when resources fluctuate where species’ niches occur in clusters along resource gradients. They have also shown that a high degree of competitive dissimilarity between clusters arises, and that this relates to the incidence of monospecific blooms of allelochemical-producing taxa, i.e. some harmful algal bloom (HAB) species. These findings further suggest that the mode (sudden v. gradual changes) under which limiting resources fluctuate plays an important role in determining the emergent properties of the assemblage. For example, productivity, biodiversity and the number of species clusters (and, therefore, resistance to HABs) are all enhanced when switches in resource supplies are gradual, compared with when they are sudden. These theoretical findings, as well as others discussed herein, are of particular interest in watersheds where human activities, such as dam construction, have the capacity to dramatically alter natural-resource fluctuation patterns.

scholarly journals A Forecasting Method for Harmful Algal Bloom(HAB)-Prone Regions Allowing Preemptive Countermeasures Based only on Acoustic Doppler Current Profiler Measurements in a Large River

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3488
Author(s):  
Geunsoo Son ◽  
Dongsu Kim ◽  
Young Do Kim ◽  
Siwan Lyu ◽  
Soojeong Kim
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Algal Bloom ◽  
Hot Spot ◽  
Harmful Algal Bloom ◽  
Spatial Association ◽  
Acoustic Doppler Current Profiler ◽  
Large River ◽  
Concentration Data ◽  
Local Index

Harmful algal blooms (HABs) have been recognized as a serious problem for aquatic ecosystems and a threat to drinking water systems. The proposed method aimed to develop a practical and rapid countermeasure, enabling preemptive responses to massive algal blooms, through which prior to the algal bloom season we can identify HAB-prone regions based on estimations of where harmful algae initiates and develops significantly. The HAB-prone regions were derived from temperature, depth, flow velocity, and sediment concentration data based only on acoustic Doppler current profilers (ADCPs) without relying further on supplementary data collection, such as the water quality. For HAB-prone regions, we employed hot-spot analysis using K-means clustering and the Getis-Ord G*, in conjunction with the spatial autocorrelation of Moran’s I and the local index of spatial association (LISA). The validation of the derived HAB-prone regions was conducted for ADCP measurements located at the downstream of Nam and Nakdong River confluence, South Korea, which preceded three months of algal bloom season monitored by unmanned aerial vehicles (UAVs). The visual inspection demonstrated that the comparison resulted in an acceptable range of agreement and consistency between the predicted HAB-prone regions and actual UAV-based observations of actual algal blooms.

scholarly journals Identification and Monitoring of Microalgal Genera Potentially Capable of Forming Harmful Algal Blooms in Punta Galeta, Panama

2019 ◽  
Vol 12 ◽  
pp. 117862211987276 ◽  
Author(s):  
Alexander González ◽  
Kathia Broce ◽  
José Fábrega-Duque ◽  
Nathalia Tejedor-Flores ◽  
Karen Young
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Growth Parameters ◽  
Harmful Algal Bloom ◽  
Health Hazard ◽  
Artificial Substrates ◽  
Easy Access ◽  
Host Preferences ◽  
Photosynthetic Organisms ◽  
Abundance Patterns

Coastal areas are attractive for human settlements because they allow easy access to benefits like food, security, and fishing. These aquatic ecosystems are supported by photosynthetic organisms that constitute the base of the food web. The term “Harmful Algal Bloom” (HAB) refers to the excessive proliferation of some taxa of these microorganisms reaching harmful levels to humans and other organisms. Biotoxins produced by these HABs could be transferred to the food chain and are the best-documented impact that HABs have on humans. The location and abundance of the HAB species producing the toxin is a good indicator of a possible human health hazard. The aim of this study was to monitor potentially harmful benthic/epibenthic microalgae in Punta Galeta, Panama over a 15-month period. The 3 main microalgae found were 2 dinoflagellates from the genera Prorocentrum and Ostreopsis and 1 diatom from the genus Coscinodiscus. Sampling made with both natural and artificial substrates yielded similar overall abundance patterns; however, for the macroalgae samples, there appeared to be significant host preferences for Ostreopsis and Coscinodiscus. Physicochemical measures taken at the site were found to fall within previously reported growth parameters for the microalgae found in the study.

Algicidal Effects of a Novel MarinePseudoalteromonas Isolate (Class Proteobacteria, Gamma Subdivision) on Harmful Algal Bloom Species of the GeneraChattonella, Gymnodinium, andHeterosigma

1998 ◽  
Vol 64 (8) ◽  
pp. 2806-2813 ◽  
Author(s):  
Connie Lovejoy ◽  
John P. Bowman ◽  
Gustaaf M. Hallegraeff
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Algal Bloom ◽  
Harmful Algal Bloom ◽  
Bacterial Species ◽  
Chattonella Marina ◽  
Alexandrium Minutum ◽  
Harmful Algal Bloom Species ◽  
High Concentrations ◽  
Algicidal Effects

ABSTRACT During a bacterial survey of the Huon Estuary in southern Tasmania, Australia, we isolated a yellow-pigmented Pseudoalteromonasstrain (class Proteobacteria, gamma subdivision), designated strain Y, that had potent algicidal effects on harmful algal bloom species. This organism was identified by 16S rRNA sequencing as a strain with close affinities to Pseudoalteromonas peptidysin. This bacterium caused rapid cell lysis and death (within 3 h) of gymnodinoids (including Gymnodinium catenatum) and raphidophytes (Chattonella marina andHeterosigma akashiwo). It caused ecdysis of armored dinoflagellates (e.g., Alexandrium catenella,Alexandrium minutum, and Prorocentrum mexicanum), but the algal cultures then recovered over the subsequent 24 h. Strain Y had no effect on a cryptomonad (Chroomonas sp.), a diatom (Skeletonema sp.), a cyanobacterium (Oscillatoria sp.), and two aplastidic protozoans. The algicidal principle of strain Y was excreted into the seawater medium and lost its efficacy after heating. Another common bacterial species, Pseudoalteromonas carrageenovora, was isolated at the same time and did not have these algicidal effects. The minimum concentrations of strain Y required to kill G. catenatum were higher than the mean concentrations found in nature under nonbloom conditions. However, the new bacterium showed a chemotactic, swarming behavior that resulted in localized high concentrations around target organisms. These observations imply that certain bacteria could play an important role in regulating the onset and development of harmful algal blooms.

Cell death in a harmful algal bloom causing species Alexandrium tamarense upon an algicidal bacterium induction

2014 ◽  
Vol 98 (18) ◽  
pp. 7949-7958 ◽  
Author(s):  
Huajun Zhang ◽  
Jinglin Lv ◽  
Yun Peng ◽  
Su Zhang ◽  
Xinli An ◽  
...  
Keyword(s):  
Cell Death ◽  
Algal Bloom ◽  
Harmful Algal Bloom ◽  
Alexandrium Tamarense ◽  
Algicidal Bacterium
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