Cyanobacteria Articles

The cyanobacterium Microcystis occurs as colonies of different sizes with varying abundance of toxic genotypes versus non-toxic genotypes under natural conditions. To investigate the effects of toxic Microcystis genotypes on natural colony formation, samples collected from the mainstream of Haihe River from July to October 2015 were sieved into four colony classes with sizes ...

May 12, 2017

By IWA Publishing

Tissue distribution of microcystin (MC)-LR-GSH, MC-LR-Cys and MC-LR of omnivorous fish in Lake Taihu was investigated. MC-LR and MC-LR-Cys were detected in liver, kidney and muscle. The concentration of MC-LR in liver and kidney was 0.052 μg g−1 DW and 0.067 μg g−1 DW, respectively. MC-LR-Cys appeared to be an important metabolite with average contents of 1.104 μg g−1 DW and ...

Dec. 7, 2016

By IWA Publishing

An actinomycete strain (KKU-A3) with algicidal activity against Microcystis aeruginosa was isolated from soil in Khon Kaen Province, Thailand. Based on its phenotypic characteristics and 16S rDNA sequence, strain KKU-A3 was identified as Streptomyces rameus. Strain KKU-A3 also exhibited algicidal activity against the cyanobacteria Synechococcus elongatus, ...

Jun. 26, 2016

By IWA Publishing

This study estimated the ability of pressurization to collapse gas vesicles and thereby enhance the settleability of fresh water cyanobacteria. Settling velocities of Pseudanabaena galeata and Microcystis aeruginosa were measured at 11 different pressure values from 0 to 0.5 MPa. The morphological variations that occurred in the gas vacuoles according to the applied pressure ...

May 4, 2016

By IWA Publishing

Microcystis occurs as colonies in the natural environment but disaggregates into single cells in laboratory cultures. In order to explore the mechanism of how Microcystis forms colonies, the zeta potentials of Microcystis cells from the laboratory and the field were studied, and the hydrophobicity of Microcystis colonies in different ...

Mar. 6, 2016

By IWA Publishing

Cylindrospermopsis raciborskii is a potentially toxic cyanobacterium that excretes organic materials which act as ligands for metals. Metal ligands may be characterized for their strength of association, e.g., stability constants, which can be either thermodynamic (K) or conditional (K’). In this research we examined K and K’ for Cu and Cd complexes with three molecular weight fractions ...

Mar. 3, 2016

By IWA Publishing

Standard ecotoxicity tests are conducted under constant and favorable experimental conditions. In natural communities, however, the toxicity of chemicals may be influenced by abiotic and biotic environmental factors. Firstly, the authors examined the influence of temperature and total food concentration on the nature of the combined effects of copper (Cu) and the cyanobacterium Microcystis ...

Feb. 15, 2016

By John Wiley & Sons, Ltd.

Recently, algicidal bacteria have attracted attention as possible agents for the inhibition of algal water blooms. In this study, an aerobic denitrifying bacterium, R11, with high algicidal activity against the toxic Microcystis aeruginosa was isolated from lake sediments. Based on its physiological characteristics and 16S rRNA gene sequence, it was identified as Raoultella, ...

Feb. 11, 2016

By IWA Publishing

Despite historical observations of potential microcystin‐producing cyanobacteria (including Leptolyngbya, Phormidium, Pseudoanabaena, and Anabaena species) in 74% of headwater streams in Alabama, Georgia, South Carolina, and North Carolina during 1993‐2011, fluvial cyanotoxin occurrence has not been systematically assessed in the southeastern United States (USA). To begin to address this data ...

Feb. 3, 2016

By John Wiley & Sons, Ltd.

Cyanobacterial hepatotoxin microcystins are a health problem found in bodies of water in Thailand. Bacteria capable of biodegrading microcystin [Dha7]MC-LR were isolated from the Bueng Nong Khot reservoir in Khon Kaen, Thailand. The bacterium Novosphingobium isolate KKU25s was shown to degrade [Dha7]MC-LR at a concentration of 25 μg l−1 at 30 °C within 24 h. ...

Sep. 20, 2015

By IWA Publishing

In spite of the great environmental and sanitary importance of cyanobacteria, their biodiversity is little known in Tunisia. In this work, a review was carried out, based on literature data, of potentially toxic cyanobacteria occurrence in Tunisia. Microcystis, one of the most widely distributed toxic bloom-forming cyanobacteria genera, was represented by Microcytis ...

Aug. 6, 2015

By IWA Publishing

Data were collected and reviewed to assess the odorous contaminant status of drinking water sources for Hangzhou City, China. β-Cyclocitral, β-ionone, dimethyl trisulfide, 2-methylisoborneol, and geosmin were targeted odorants. Results indicate that β-cyclocitral was the main contaminant in source waters as it was most frequently detected and occurred at ...

May 3, 2015

By IWA Publishing

Microcystin‐LR (MC‐LR) has the potential to disturb thyroid hormone (TH) homeostasis, but little is known of the underlying mechanisms of MC‐LR in fish. In the present study, juvenile Chinese rare minnows (Gobiocypris rarus) were exposed to various concentrations of MC‐LR (0, 50, 100, and 500 μg/L) for 7 d. The whole‐body content of THs, the histology of thyroid follicle epithelial cells, the ...

Apr. 20, 2015

By John Wiley & Sons, Ltd.

Our previous work revealed that Acacia mearnsii extract can inhibit the growth of Microcystis aeruginosa, the common species forming toxic cyanobacterial blooms in eutrophic freshwater. In the present study, we demonstrated that this plant extract can significantly increase cell membrane permeability and Ca2+/Mg2+-ATPase activity on the ...

Mar. 26, 2015

By IWA Publishing

The authors characterized global cytosine methylation levels in two different genotypes of the ecotoxicological model organism Daphnia magna after exposure to a wide array of biotic and abiotic environmental stressors. The study aimed to improve the authors' understanding of the role of cytosine methylation in the organism‘s response to environmental conditions. The authors observed a ...

Jan. 11, 2015

By John Wiley & Sons, Ltd.

Microcystins are toxic peptides secreted by certain waterblooms of toxic cyanobacteria. The most widely studied microcystin is microcystin‐LR (MC‐LR), which exhibits hepatotoxicity and neurotoxicity. However, limited information is available regarding the effects on offspring following maternal exposure. The present study is to observe the effects of progestational exposure to MC‐LR on ...

Oct. 14, 2014

By John Wiley & Sons, Ltd.

Aquatic organisms often suffer episodic stress from cyanobacterial bloom‐derived concomitant and sometimes interactive stressors, and may recover when stressors terminate. To assess whether exposed Daphnia can quickly recover from combined toxicity of bloom‐derived stressors, we exposed Daphnia similoides to mixtures of ammonia (0, 0.37, and 0.58 mg L−1) and dissolved microcystin‐LR (0, 10, ...

Jul. 30, 2014

By John Wiley & Sons, Ltd.

In this study we investigated the effects of six different genera of cyanobacteria on multiple endpoints of Daphnia magna in a 21‐day life‐table experiment conducted at three different temperatures (15°C, 19°C and 23°C). The specific aims were to test (1) if the effect of temperature on Daphnia's sensitivity to cyanobacteria was the same or different among different cyanobacteria and (2) if ...

Jul. 6, 2014

By John Wiley & Sons, Ltd.

The work describes the results of experiments aimed at developing a new method using synthetic polymers to remove microcystins from water. Three hydrophilic polymers were synthesized based on a N-vinylformamide (NVF) structure cross-linked with divinylbenzene (DVB): p(NVF-co-DVB), p(VAm-co-DVB), and, after reaction with glutaraldehyde (GA), p(VAm-co-DVB)GA. The physicochemical ...

Apr. 13, 2014

By IWA Publishing

We investigated the availability of different forms of particulate soil phosphorus (P) to Microcystis aeruginosa by sequential extraction and bioassay. We cultured M. aeruginosa in media containing, as the sole source of P, soils sequentially extracted with 1 M NH4Cl, 0.11 M bicarbonate dithionite, 1 M NaOH, and 0.5 M HCl. Analyses of ...

Mar. 18, 2014

By IWA Publishing