Microcystin production by Radiocystis fernandoi (Chroococcales, Cyanobacteria) isolated from a drinking water reservoir in the city of Belém, PA, Brazilian Amazonia region

• Published in: Toxicon (Oxford) Vol. 42; no. 7; pp. 709 - 713
• Main Authors: Vieira, José Maria dos S, Azevedo, Maria Teresa de P, Azevedo, Sandra Maria Feliciano de Oliveira, Honda, Ricardo Yukio, Corrêa, Benedito
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-12-2003; Elsevier Science
• Subjects: Bacterial Toxins - analysis; Bacterial Toxins - biosynthesis; Bacteriology; Biological and medical sciences; Brazil; Chromatography, High Pressure Liquid; Chroococcales; Cyanobacteria; Cyanobacteria - isolation & purification; Cyanobacteria - metabolism; Cyanophyta; Cyanotoxins; Fundamental and applied biological sciences. Psychology; Humans; Microbiology; Microcystins; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; Peptides, Cyclic - analysis; Peptides, Cyclic - biosynthesis; Radiocystis; Radiocystis fernandoi; Toxic cyanobacteria; Water Microbiology; Water Supply; South America; Brazil; America; Brazil, Para, Belem; Brazil, Amazonia; Radiocystis fernandoi; Cyanotoxins; Toxic cyanobacteria; Microcystins; Cell proliferation; Drinking water; Intraperitoneal administration; Bioassay; Toxicity; Body weight; Rodentia; Hepatic disease; Vertebrata; Mammalia; Mouse; Animal; Cyanobacteria; Production; Digestive diseases; Bacteria; Isolation; Water pollution; Biological contamination
• ISSN: 0041-0101; 1879-3150
• DOI: 10.1016/j.toxicon.2003.08.004

During the monitoring of toxic cyanobacteria in the Utinga Reservoir, which is the main drinking water supply for the city of Belém, PA, Brazil, a
Radiocystis fernandoi strain (SPC714) was isolated. This non-axenic strain was submitted to a toxicity bioassay with mice and microcystin production analyzed by HPLC-DAD. The species was identified based on cultured and natural preserved material. Morphometric, developmental and reproductive characteristics were analyzed. The strain was cultured in liquid ASM-1 medium, at 25±1 °C, at an incident irradiance of 20
μmol
photon
m
−2
s
−1 and constant aeration. At the end of the exponential growth phase, cells were lyophilized and submitted to toxicity tests. The strain showed high toxicity to mice, by intraperitoneal route, with an approximate LD
100 of 60 mg kg
−1 of body weight, producing characteristic symptoms of hepatotoxicity. Analyses performed by HPLC-DAD confirmed the production of microcystins, in a concentration of 3.83 μg mg
−1 of lyophilized cells. This is the first reference related to the toxicity of the genus
Radiocystis.