Microcystis

In the Slimmer of 1989, Rutland Water, the largest man-made lake in Western Europe and which supplies potable water to approximately 500 000 people in the East of England, contained a heavy bloom of Microcystis aeruginosa. By the end of the summer, a number of sheep and dogs had died after drinking from the bloom and concentrated scum. Analysis revealed that the cyanobacterial bloom material was toxic to laboratory mice, and that rumen contents from a poisoned sheep contained fivemicrocystin variants.Microcystins were detected in waters used for recreation in Australia at concentrations greater than 1 mg per... 

Lehman PW, Boyer G, Waller C, Gehrts K (2005) Distribution and toxicity of a colonial Microcystis aeruginosa bloom in the San Erancisco Bay Estuary. Hydrobiologia 541 87-99... 

Lehman PW, Boyer G, Satchwell M, Waller S (2008) The influence of environmental conditions on the seasonal variation of Microcystis cell density and microcystins concentration in San Erancisco Estuary. Hydrobiologia 600 187-204... 

Figure 8. Left The cyclic heptapeptide hepatotoxin microcystin-LA (cyanoginosin-LA) produced by the colonial cyanobacterium Microcystis aeruginosa strain WR-70 (UV-010). MW = 909. Right The cyclic heptapeptide hepatotoxin microcystin-LR (cyanoginosin-LR) produced by a waterbloom of the colonial cyanobacterium Microcystis aeruginosa collected in Lake Akersvatn, Norway, 1984-85 MW=994, 69J1).

HSCCC was successfully applied for the first time to the isolation and purification of zeaxanthin from cyanobacterium Microcystis aeruginosa. Adducts of flavonols and anthocyans were also isolated using this method. ... 

Chen, F. et al.. Isolation and purification of the bioactive carotenoid zeaxanthin from the microalga Microcystis aeruginosa by high-speed counter-current chromatography, J. Chromatogr, 1064, 183, 2005. 

Legend Pond A - normal diversity of phytoplankton Pond B - Microcystis sp. bloom Pond C - very little phytoplankton Pond D - dense growth E. mlcrocarpa 1 - laboratory cultures (++) major peak, (+) minor peak... 

Welker, M. Brunke, M. Preussel, K. Lippert, I. von Dohren, H. Diversity and distribution of microcystis (Cyanobacteria) oligopeptide chemotypes from natural communities studied by single-colony mass spectrometry. Microbiology 2004,150, 1785-1796. 

Juttner, F. (1976). Beta-cyclocitral and alkanes in microcystis (cyanophyceae). Zeitschrift Naturforschung C 31(9-10) 491 195. 

Juttner, F. (1988). Carotene oxygenase in microcystis. Meth. Enzymol. 167 336-341. 

Walsh, K., G. J. Jones et al. (1998). Effects of high irradiance and iron concentration on pigment and fatty acid composition in the cyanobacterium Microcystis aeruginosa. Mar. Freshwater Res. 49(5) 399 107. 

In our previous research, we found that the antialgal allelochemical Ethyl 2-Methylacetoacetate (EMA) caused loss of cell membrane integrity. It hinted that EMA may cause a change in the membrane. It is reported that environmental stress may increase the concentration of ROS in plant cell. The excessive ROS may cause a decrease of antioxidation enzymes activity and lipid peroxidation. The effect of EMA on the activity of SOD and POD and lipid fatty acids of Chlorella pyrenoidosa, Chlorella vulagaris and Microcystis aeruginosa were evaluated to elucidate the mode of action of EMA. 

Zheng XH, Xiao L, Ren J, Yang LY (2008) The effect of a Microcystis aeruginosa bloom on the bacterioplankton community composition of Lake Xuanwu. J Freshwater Ecol 23 297-304... 

Rapid-acting cytotoxin that disrupts cell membranes in the liver (hepatoxin) causing an accumulation of blood in the liver. It is the most toxic of the Microcystins. It is a solid obtained from freshwater blue-green cyanobacteria (Microcystis aeruginosa, Microcystis cyanea). It is heat stable and water soluble. Aqueous solutions are "probably stable" and resistant to chlorine at 100 ppm. It is also soluble in alcohol and acetone. 

Significant concentrations of cyanotoxins have been found to accumulate in the tissues of macroinvertebrates such as mollusks and crustaceans, presenting an indirect route of exposure for invertebrates, fish, and aquatic mammals at higher trophic levels (Negri and Jones 1995). In natural systems, mortality among benthic invertebrate herbivores is probably low because most bloom-forming bacteria are planktonic and only periodically come into contact with the benthos. Nevertheless, Kotak et al. (1996) determined that enhanced mortality of snails at the end of a bloom cycle in Canadian lakes was due to consumption of Microcystis cells that had formed a scum on the surface of macrophytes. Oberemm et al. (1999) found that aqueous microcystins, saxitoxins, and anatoxin-a all resulted in developmental delays in fish and salamander embryos. Interestingly, more severe malformations and enhanced mortality were observed when larvae were exposed to crude cyanobacterial extracts than to pure toxins applied at natural concentrations (Oberemm et al. 1999). 

Fulton III RS, Paerl HW (1987) Toxic and inhibitory effects of the blue-green alga Microcystis aeruginosa on herbivorous zooplankton. J. Plankton Res 9 837-855 Gilbert JJ (1990) Differential effects of Anabaena afflnis on cladocerans and rotifers mechanisms and implications. Ecology 71 1727-1740... 

APHA Selenastrum capricornutum, Species-dependent Microcystis aeruginosa, between 103 and Anabaena flos-aquae, 50 X 103 Cyclotella sp. Nitzschia sp. Synedra sp. APHAb Growth rate 24 2 32-65 pmol m 2 s 1... 

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