Browsing by Author "Wiegand, C."

Now showing 1 - 6 of 6
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    Analysis of the cyanotoxins anatoxin-a and microcystins in Lesser Flamingo feathers.
    (Taylor & Francis, 2006) Metcalf, J.S.; Morrison, L.F.; Krienitz, L.; Ballot, A.; Krause, E.; Kotut, Kiplagat; Pütz, S.; Wiegand, C.; Pflugmacher, S.; Codd, G.A.
    Feathers from carcasses of the Lesser Flamingo (Phoeniconaias minor), which had died after ingesting cyanobacterial toxins (cyanotoxins) contained between 0.02 and 30.0 µg microcystin-LR equivalents per gram of feather according to HPLC and ELISA analysis of feather extracts. Anatoxin-a was detected less frequently in the Lesser Flamingo feathers, up to 0.8 µg anatoxin-a per gram of feather being recorded. When feathers from different body regions were analysed and compared for microcystins and anatoxin-a, wing feathers were found to contain the highest concentrations of these cyanotoxins, the order of concentration and frequency of analytical detection being wing > breast > head. Consistent with the presence of the microcystins and anatoxin-a in gut contents and the livers of the dead birds and negligible in vitro adsorption to feathers, the cyanotoxins associated with the feathers of the dead wild flamingos are inferred to be primarily of dietary origin
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    Contribution of hot spring cyanobacteria to the mysterious deaths of Lesser Flamingos at Lake Bogoria, Kenya
    (Elsevier, 2003-03-01) Krienitz, L.; Ballot, A.; Kotut, Kiplagat; Wiegand, C.; Pütz, S.; Metcalf, J.S.; Codd, G.A.; Pflugmacher, S.
    Cyanobacterial mats at hot springs on the shore of the alkaline Lake Bogoria, Kenya, were investigated regarding species community and cyanobacterial toxin content. The hepatotoxins microcystin-LR, -RR, -LF and -YR, and the neurotoxin anatoxin-a were present. The mats were dominated by Phormidium terebriformis, Oscillatoria willei, Spirulina subsalsa and Synechococcus bigranulatus. The concentration of microcystins in mat samples, ranged from 221 to 845 microg microcystin-LR equivalents g(-1) DW of mat. Anatoxin-a concentrations ranged from 10 to 18 microg g(-1) DW of mat. A contribution of the cyanobacterial toxins from the hot spring mats to the mass mortalities of Lesser Flamingos is suggested by: (a), the presence of hot spring cyanobacterial cells and cell fragments, and high concentrations of the cyanobacterial hepato- and neurotoxins in flamingo stomach contents and faecal pellets; (b), observations of neurological signs of bird poisoning at the lake. Cyanobacterial toxins in stomach contents, intestine and fecal pellets were 0.196 microg g(-1) fresh weight (FW) for the microcystins and 4.34 microg g(-1) FW for anatoxin-a. Intoxication with cyanobacterial toxins could occur by uptake of detached cyanobacterial cells from the mats, as the flamingos need to drink fresh or brackish water, and to wash their feathers daily, which they do in the vicinity of the hot springs, where salinity is lower than in the main body of water of the lake.
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    Contribution of tixic cynobacteria to massive deaths of lesser flamingoes at saline-alkaline lakes of Kenya
    (2003) Krienitz, L.; Ballot, A.; Casper, P.; Codd, G.A.; Kotut, Kiplagat; Metcalf, J.S.; Morrison, L.F.; Pflugmacher, S.; Wiegand, C.
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    A cyano-anomaly? Cyanobacterial toxins as contributors to Lesser Flamingo mass deaths
    (2003-10) Codd, G.A.; Metcalf, J.S.; Morrison, L.F.; Krienitz, L.; Ballot, A.; Pflugmacher, S.; Wiegand, C.; Kotut, Kiplagat
    In the present study, significative HAB’S bloom was confirmed in Matanchén Bay during Febrary 2003. The Raphidophice Fibrocapsa cf. japonica, Toriumi et Takano 1973 (=Chatonella japonica) has dominated (97%) red tide event occurring lately in coastal waters of Nayarit state, with high cell concentration of 4-6 millions of cells per liter of water. The duration of this bloom could not be determined exactly due to limiting sampling. There have been no reports of fish kills or human intoxication in the locality. This study represents the first survey on the distribution of Fibrocapsa cf. • Mexico japonica in the Mexican Pacific coast. The finding adds Raphidophyceans to the list of harmful algal blooms and toxin producers in Mexico.
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    Cyanobacteria and cyanobacterial toxins in the alkaline crater lakes Sonachi and Simbi, Kenya
    (Elsevier, 2005-01) Ballot, A.; Krienitz, L.; Kotut, Kiplagat; Wiegand, C.; Pflugmacher, S.
    The phytoplankton communities and the production of cyanobacterial toxins were investigated in two alkaline Kenyan crater lakes, Lake Sonachi and Lake Simbi. Lake Sonachi was mainly dominated by the cyanobacterium Arthrospira fusiformis, Lake Simbi by A. fusiformis and Anabaenopsis abijatae. The phytoplankton biomasses measured were high, reaching up to 3159 mg l−1 in L. Sonachi and up to 348 mg l−1 in L. Simbi. Using HPLC techniques, one structural variant of the hepatotoxin microcystin (microcystin-RR) was found in L. Sonachi and four variants (microcystin-LR, -RR, -LA and -YR) were identified in L. Simbi. The neurotoxin anatoxin-a was found in both lakes. To our knowledge this is the first evidence of cyanobacterial toxins in L. Sonachi and L. Simbi. Total microcystin concentrations varied from 1.6 to 12.0 μg microcystin-LR equivalents g−1 DW in L. Sonachi and from 19.7 to 39.0 μg microcystin-LR equivalents g−1 DW in L. Simbi. Anatoxin-a concentrations ranged from 0.5 to 2.0 μg g−1 DW in L. Sonachi and from 0 to 1.4 μg g−1 DW in L. Simbi. In a monocyanobacterial strain of A. fusiformis, isolated from L. Sonachi, microcystin-YR and anatoxin-a were produced. The concentrations found were 2.2 μg microcystin g−1 DW and 0.3 μg anatoxin-a g−1 DW. This is the first study showing A. fusiformis as producer of microcystins and anatoxin-a. Since A. fusiformis occurs in mass developments in both lakes, a health risk for wildlife can be expected.
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    Cyanotoxin-producing bloom of Anabaena flos-aquae, Anabaena discoidea and Microcystis aeruginosa (Cyanobacteria) in Nyanza Gulf of Lake Victoria, Kenya
    (2002) Krienitz, L.; Ballot, A.; Wiegand, C.; Kotut, Kiplagat; Codd, G.A.; Pflugmacher, S.
    A bloom of Anabaena flos-aquae, Anabaena discoidea and Microcystis aeruginosa, was characterized in Nyanza Gulf of Lake Victoria, near Kisumu, Kenya. According to classical literature data, A. discoidea was considered to be endemic to the Great Lakes of Africa. Its morphological characteristics are described and discussed in relation to A. flos-aquae. The two samples investigated contained the cyanobacterial toxins, microcystin-LR, -RR, -LA and -LF.