Aphanizomenon

Preufiel K, Stiiken A, Wiedner C, Chorus I, Fastner J (2006) First report of cylindrospermopsin producing Aphanizomenon flos-aquae (Cyanobacteria) from two German lakes. Toxicon... 

The saxitoxins have also been found in the freshwater cyanophyte Aphanizomenon flos aquae (9,1 ) and, quite recently, in tropical marine coralline algae of the genus Jania (11)... 

The main genera responsible for freshwater toxic blooms are Microcystis, Anabaena, Aphanizomenon and Oscillatoria. Toxins produced include 1. anatoxins, alkaloids and peptides of Anabaena 2. the peptide microcystin and related peptides of Microcystis 3. aphantoxins, compounds of Aphanizomenon with properties similar to some paralytic shellfish poisons. Properties of Oscillatoria toxin suggest they are peptides similar to those of Microcystis. Microcystis toxins are peptides (M.W. approx. 1200) which contain three invariant D-amino acids, alanine, erythro-3-methyl aspartic and glutamic acids, two variant L-amino acids, N-methyl dehydro alanine and a 3-amino acid. Individual toxic strains have one or more multiples of this peptide toxin. The one anatoxin characterized is a bicylic secondary amine called anatoxin-a (M.W. 165). The aphantoxin isolated in our laboratory contains two main toxic fractions. On TLC and HPLC the fractions have the same characteristics as saxitoxin and neosaxitoxin. 

Two other suspected alkaloid producing cyanobacteria strains, Anabaena flos-aquae NRC-525-17 and Aphanizomenon flos-aquae NH-5, are now being studied. The toxin of flos-aquae NRC-525-17 (anatoxin-a(s)) is thought to have CNS stimulating properties (7) and that of Aph. flos-aquae NH-5 (aphantoxin) is thought to produce the paralytic shellfish poisons saxitoxin and neosaxitoxin (Fig. 1)... 

Figure 1. Structure of anatoxin-a from Anabaena flos-aquae NRC-44-1, saxitoxin and neosaxitoxin. Saxitoxin and neosaxitoxin is produced by certain species of marine algae and by the freshwater cyanobacteria Aphanizomenon flos-aquae NH-5.

TABLE 1. Thin-layer chromatography of Aphanizomenon flos-aquae NH-5 fractions from Bio-gel P-2 gel filtration... 

Cyanobacterial toxins (both marine and freshwater) are functionally and chemically a diverse group of secondary chemicals. They show structure and function similarities to higher plant and algal toxins. Of particular importance to this publication is the production of toxins which appear to be identical with saxitoxin and neosaxitoxin. Since these are the primary toxins involved in cases of paralytic shellfish poisons, these aphantoxins could be a source of PSP standards and the study of their production by Aphanizomenon can provide information on the biosynthesis of PSP s. The cyanobacteria toxins have not received extensive attention since they have fewer vectors by which they come in contact with humans. As freshwater supplies become more eutrophicated and as cyanobacteria are increasingly used as a source of single cell protein toxic cyanobacteria will have increased importance (39). The study of these cyanobacterial toxins can contribute to a better understanding of seafood poisons. 

However, both "rafted" and "non-rafted" cultures from Klamath Lake, Oregon were found to be toxic (S3. The toxicity of Aphanizomenon was firmly established in 1968 ( ). 

Intermittently, we have sampled almost monospecific blooms of both Aphanizomenon and Microcystis. Samples of M. aeruginosa were... 

Cylindrospermopsin has also been isolated from Umezakia natans and Aphanizomenon ovalisporum. Algal blooms that produce cylindrospermopsin are widespread in tropical waters where occurrences of gastro-... 

Neurotoxin Anabaena, Aphanizomenon, Oscillatoria, Lyngbya, Cylindrospermopsis, Alexandrium, Gymnodinium, Pyrodinium Australia, Brazil, Portugal, USA... 

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