title: Biodegradation of microcystins by aquatic Burkholderia sp. from a South Brazilian coastal lagoon.
abstract: Biological degradation of cyanobacterial hepatotoxin microcystins in estuarine and coastal water samples from the Patos Lagoon estuarine system, a coastal lagoon situated at the southernmost region of Brazil, was observed. Samples of natural surface water were spiked with purified and semi-purified microcystins (MC-LR and [D-Leu(1)]MC-LR) and their concentrations were monitored by HPLC analysis. After 15 days, the toxins were no longer detectable and after 43 days less than 90% of the initial concentration added to the samples was detected by ELISA. The average degradation rates and the exponential decay rate constants from inside and outside of the estuary were similar. A microcystin degradative bacterium was isolated from the estuarine region. Partial sequence of the 16S rDNA showed a 96% homology with the Burkholderia genus. This genus belongs to the beta subdivision on proteobacteria. This is the first report showing the genus Burkholderia as a cyanobacterial toxin degrader.
authors.affiliation: Fundação Universidade Federal do Rio Grande (FURG), Av. Itália Km 08, 96201-900 Rio Grande-RS, Brazil.
authors.forename: Gilmar A F
authors.initials: GA
authors.lastname: Lemes
authors.forename: Ralf
authors.initials: R
authors.lastname: Kersanach
authors.forename: Luciano da S
authors.initials: Lda S
authors.lastname: Pinto
authors.forename: Odir A
authors.initials: OA
authors.lastname: Dellagostin
authors.forename: João S
authors.initials: JS
authors.lastname: Yunes
authors.forename: Alexandre
authors.initials: A
authors.lastname: Matthiensen
mesh_terms: D001673:Biodegradation, Environmental; D001938:Brazil; D019117:Burkholderia / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D005618:Fresh Water / Q000382:microbiology; D005843:Geography; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D052998:Microcystins / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D013696:Temperature
chemical_list: D004269:DNA, Bacterial; D052998:Microcystins; C078588:microcystin