• Bulletin of the Korean Chemical Society
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• v.26 no.2
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• pp.268-272
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• 2005

Different detection characteristics of fluorescence immunochromatography method and high performance liquid chromatography (HPLC) method for the analysis of cyanobacterial toxins were studied. In particular, low and high limits of detection, detection time and reproducibility and detectable microcystin species were compared when fluorescence immunochromatography method and high performance liquid chromatography method were applied for the detection of microcystin (MC), a cyclic peptide toxin of the freshwater cyanobacterium Microcystis aeruginosa. A Fluorescence immunochromatography assay system has the unique advantages of short detection time and low detection limit, and high performance liquid chromatography detection method has the strong advantage of individual quantifications of several species of microcystins.

• Bulletin of the Korean Chemical Society
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• v.28 no.5
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• pp.800-804
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• 2007

Cyanobacterial toxins, microcystins are very potent hepatotoxins and their occurrence has been reported all over the world. They could threaten human health when toxic Microcystis occurs in water supply reservoirs. In this study, the effects of several environmental factors on production and degradation of toxins produced by cyanobacteria in Lake Soyang have been studied. A new rapid quantification method of microcystins using fluorescence for a detection signal and a lateral-flow-type immunochromatography as a separation system was used. Culture age, temperature, light intensity, pH, N-nutrient concentration, P-nutrient concentration, iron and zinc concentration were the most importantly examined factors. The toxin content was the highest on 17-18 days and at temperatures between 20℃ and 25℃, and at pH between 8.4 and 8.8.

• Applied Chemistry for Engineering
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• v.8 no.4
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• pp.610-616
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• 1997

Hepatotoxic cyanobacteria, Microcystis species, were collected from the Nakdong River and we could isolate hepatotoxins, microcystin-LR and microcystin-RR, which are also strong inhibitors of protein phosphatase 1 and 2A. From the microcystins, several microcystin derivatives were synthesized and tested on the mouse toxicity in order to establish the structure-activity relationship. Esterification od carboxyl groups of Glu and MeAsp residue produced nontoxic compounds. However, when we reduced the Mdha residue with sodium borohydride into Ala residue, toxicity was still maintained. Also, the change of guanidyl moiety of Arg residue in microcystin-LR into dimethylpyrimidyl moiety did not change the toxicity of microcystins as well. Thus the carboxyl groups seem to play important roles in binding with protein phosphatase 1 and 2A, whereas Mdha residue and the guanidyl moiety of Arg residue do not.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.162-168
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• 2010

The sequence diversity of mcyA gene involved in synthesis of microcystins was analyzed in Microcystis spp. isolated from the Korean reservoirs and in the environmental samples taken from the Daechung, Chungju, Yongdam, Soyang, and Euam Reservoirs at the cyanobacterial blooming season. It was estimated that the sequences of mcyA gene in the isolated Microcystis spp. were much conserved when compared with those in GenBank database. A few kinds of clones were dominant in the investigated environmental samples, occupying 87 to 100% of total clones. No mcyA sequences originated from Anabaena spp. or Planktothrix spp. was found. These results indicated that microcystins are produced mainly by Microcystis spp. and the sequences of mcyA genes are much conserved in the investigated Korean reservoirs.

• Journal of Food Hygiene and Safety
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• v.39 no.3
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• pp.191-208
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• 2024

The peptide-type hepatotoxins microcystins (MCs) and nodularin (NOD) are secondary metabolites produced by cyanobacteria. MCs and NOD can bioaccumulate in agricultural products through toxin-contaminated water, soil, and manure and can cause human health risks through the consumption of agricultural products. As interest in the contamination of agricultural products by MCs or NOD has recently emerged, occurrence studies based on various analysis methods for agricultural products have been conducted. However, studies on agricultural products are still insufficient compared to research on drinking water and seafood. In addition, research is primarily conducted on agricultural products grown in areas where green algae occur, but not on marketed products. In the present study, we review the physicochemical properties, toxicity, analysis methods, occurrence studies, and management status of MCs and NOD in agricultural products to build a foundation for systematic monitoring and safety management.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.12
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• pp.657-667
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• 2015

Cyanobacteria frequently dominate the freshwater phytoplankton community in eutrophic waters. Cyanotoxins can be classified according to toxicity as neurotoxin (Anatoxin-a, Anatoxin-a(s), Saxitoxins) or hepatotoxin (microcystins, nodularin, cylindrospermopsin). Microcystins are present within cyanobacterial cells generally, and they are extracted by the damage of cell membrane. It has been reported that cyanotoxins caused adverse effects and they are acculmulated in aquatic oganisms of lake, river and ocean. In natural, microcystins are removed by biodegradation of microorganisms and/or feeding of predators. However, in process of water treatment, the use of copper sulfate to remove algal cells caused extraction of a mess of microcystins. Microcysitns are removed by physical, chemical and biological methods according to reports. The reduction of nutrients (N and P) inflow is basic method of prevention of cyanobacteria bloom formation. However, it is less effective than investigation because nutrients already present in the eutrophic lake. In natural lake, cyanobacteria bloom are not formed because macrophytes invade from coastal lake by eutrophication. Therefore, a coastal lake has to recover to prevent of cyanobacteria bloom formation.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.370-385
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• 2023

Cyanobacterial harmful algal blooms (Cyano-HABs) are an international environmental problem that negatively affects the ecosystem as well as the safety of water resources by discharging cyanotoxins. In particular, the discharge of microcystins (MCs), a highly toxic substance, has been studied most actively, and various water treatment methods have been proposed for this purpose. In this paper, we reviewed adsorption technology, which is recognized as the most feasible, economical, and efficient method among suggested treatment methods for removing MCs. Activated carbons (AC) are widely used adsorbents for MCs removal, and excellent MCs adsorption performance has been reported. Research on alternative adsorption materials for AC such as biochar and biosorbents has been conducted, however, their performance was lower compared to activated carbon. The impacts of adsorbent properties(characteristics of pore surface chemistry) and environmental factors (solution pH, temperature, natural organic matter, and ionic strength) on the MCs adsorption performance were also discussed. In addition, toward effective control of MCs, the possibility of the direct removal of harmful cyanobacteria as well as the removal of dissolved MCs using adsorption strategy was examined. However, to fully utilize the adsorption for the removal of MCs, the application and optimization under actual environmental conditions are still required, thereby meeting the environmental and economic standards. From this study, crucial insights could be provided for the development and selection of effective adsorbent and subsequent adsorption processes for the removal of MCs from water resources.

• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.190.2-190
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• 1998

No Abstract, See Full Text

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2004.05a
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• pp.41-41
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• 2004

• Journal of Korean Society on Water Environment
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• v.26 no.5
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• pp.834-840
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• 2010

To find out the toxin production characteristics of Korean harmful cyanobacteria, we isolated 14 cyanobacterial strains from Korean lakes and rivers and analyzed the kinds and cellular content of microcystins (MCYSTs) of cyanobacterial isolates using cultured biomass. And we measured the MCYSTs production by growth phase of two representative toxic strains, Microcystis aeruginosa (HG-015) and Anabaena planktonica (HG-012). Among seven cyanobacteral species, Microcystis wesenbergii showed the highest cellular MCYSTs content. MCYST-RR was the most dominant toxin reaching more than 85% of MCYSTs produced by isolated cyanbacterial strains. During the mass culture, Microcystis aeruginosa (HG-015) showed the highest yield and accumulation of MCYSTs in the exponential growth phase. However the cellular content of chlorophyll a and MCYSTs of Anabaena planktonica (HG-012) showed higher value in the stationary and early death phase than in the exponential growth phase. Our results suggest that control and removal of harmful cyanobacterial bloom before exponential growth phase may be effective to prevent health risk of cyanobacterial toxins in the drinking water sources.