Isolation and Identification of the Fast-Death Factor in Microcystis Aeruginosa NRC-1

Abstract

The fast-death factor in Microcystis aeruginosa NRC-1 is an acidic, probably cyclic peptide containing the following amino acids in the molar ratios indicated: L-aspartic (1); L-glutamic (2); D-serine (1); L-valine (1); L-ornithine (1); L-alanine (2); L-leucine (2). It is possible, although not likely, that one of the residues of glutamic, alanine, or leucine also is in the D-configuration. The toxin, in the form of its sodium salt, was extracted from lyophilized algal cells by water, separated from pigments by extraction into n-butanol, and freed from high-molecular-weight impurities by dialysis. No separation of a single toxic compound could be obtained by countercurrent distribution, chromatography, or electrophoresis in carbonate, acetate, or phosphate buffers. Electrophoresis of the crude toxin on cellulose in 0.1 M borate yielded five peptides one of which was toxic and accounted for 100% of the toxicity present in the crude preparation. The intraperitoneal LD50 of the pure toxin for mice was 0.466 ± 0.013 mg/kg body weight.

Evidence for a Novel Marine Harmful Algal Bloom: Cyanotoxin (Microcystin) Transfer from Land to Sea Otters

“…On the microscope, livers of microcystin-positive sea otters exhibited hepatocellular vacuolation, apoptosis, necrosis and hemorrhage (Fig. 6) consistent with previous descriptions of microcystin intoxication in humans and animals [1], [12], [13], [46], [13,47]. In contrast, livers from 2 captive sea otters (Table 1) and 19 wild otters without evidence of primary liver disease (data not shown) tested negative for microcystin.…”

Reviews of Environmental Contamination and Toxicology

“…Various cyanobacterial strains producing different types of neurotoxins are illustrated in Table l. (Bishop et al 1959). Some M. aeruginosa strains such as NRC-I (SS-17) produce a single toxin, while others are capable of producing several toxins.…”

Highly Toxic Microcystis aeruginosa Strain, Isolated from São Paulo—Brazil, Produce Hepatotoxins and Paralytic Shellfish Poison Neurotoxins

“…Microcystins are cyclic heptapeptides and are known to be toxic to aquatic biota, livestock, and humans (Carmichael 1996;Jochimsen et al 1988;Falconer et al 1999). Microcystins were first described in 1959, in a culture of M. aeruginosa (Bishop et al 1959), and their structure was elucidated in 1984 (Botes et al 1984). At present, more than 70 structural variants of these peptides are known (Sivonen and Jones 1999;Codd et al 2005).…”