Biodegradation of [D-Leu 1 ] microcystin-LR by a bacterium isolated from sediment of Patos Lagoon estuary, Brazil

Journal of venomous animals and toxins

Gilmar AF Lemes¹  Joã²  o S Yunes²  Mauricio R Bogo⁴  Luiza W Kist⁵ 

[1] LaboratóLaboratory of Genomics and Molecular Biology, School of Biosciences, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Porto Alegre, Brazil;National Institute of Science and Technology for Translational Medicine, Porto Alegre, Brazil;rias e Ficotoxinas, Instituto de Oceanografia, Universidade Federal do Rio Grande (FURG), Rio Grande, Brazil;rio de Cianobacté

关键词: Biodegradation;    Microcystin;    Sediment;    Patos Lagoon;    Estuary;    Brazil;   

DOI  :  10.1186/s40409-015-0001-3

学科分类：药理学

来源: BioMed Central

【 摘 要 】

Toxic cyanobacterial blooms are recurrent in Patos Lagoon, in southern Brazil. Among cyanotoxins, [D-Leu1] microcystin-LR is the predominant variant whose natural cycle involves water and sediment compartments. This study aimed to identify and isolate from sediment a bacterial strain capable of growing on [D-Leu1] microcystin-LR. Sediment and water samples were collected at two distinct aquatic spots: close to the Oceanographic Museum (P1), in Rio Grande City, and on São Lourenço Beach (P2), in São Lourenço do Sul City, southern Brazil. [D-Leu1] microcystin-LR was isolated and purified from batch cultures of Microcystis aeruginosa strain RST9501. Samples of water and sediment from Rio Grande and São Lourenço do Sul were collected. Bacteria from the samples were allowed to grow in flasks containing solely [D-Leu1] microcystin-LR. This strain named DMSX was isolated on agar MSM with 8 g L−1 glucose and further purified on a cyanotoxin basis growth. Microcystin concentration was obtained by using the ELISA immunoassay for microcystins whereas bacterial count was performed by epifluorescence microscopy. The genus Pseudomonas was identified by DNA techniques. Although several bacterial strains were isolated from the samples, only one, DMXS, was capable of growing on [D-Leu1] microcystin-LR. The phylogenetic analysis of the 16S rRNA gene from DMXS strain classified the organism as Pseudomonas aeruginosa. DMXS strain incubated with [D-Leu1] microcystin-LR lowered the amount of toxin from 1 μg.L−1 to 

【 授权许可】

CC BY