title: Microcystin production by Radiocystis fernandoi (Chroococcales, Cyanobacteria) isolated from a drinking water reservoir in the city of Belém, PA, Brazilian Amazonia region.
abstract: 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 degrees C, at an incident irradiance of 20 micromol 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 LD100 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 microg mg(-1) of lyophilized cells. This is the first reference related to the toxicity of the genus Radiocystis.
authors.affiliation: Departamento de Farmácia, Centro de Ciências da Saúde, Universidade Federal do Pará, 66075-110 Belém, PA, Brazil.
authors.forename: José Maria
authors.initials: JM
authors.lastname: dos S Vieira
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: de P Azevedo
authors.forename: Sandra Maria Feliciano
authors.initials: SM
authors.lastname: de Oliveira Azevedo
authors.forename: Ricardo Yukio
authors.initials: RY
authors.lastname: Honda
authors.forename: Benedito
authors.initials: B
authors.lastname: Corrêa
mesh_terms: D001427:Bacterial Toxins / Q000032:analysis / Q000096:biosynthesis*; D001938:Brazil; D002851:Chromatography, High Pressure Liquid; D000458:Cyanobacteria / Q000302:isolation & purification* / Q000378:metabolism*; D006801:Humans; D052998:Microcystins; D010456:Peptides, Cyclic / Q000032:analysis / Q000096:biosynthesis*; D014871:Water Microbiology; D014881:Water Supply
chemical_list: D001427:Bacterial Toxins; D052998:Microcystins; D010456:Peptides, Cyclic; C078588:microcystin