Cyanotoxin degradation activity and mlr gene expression profiles of a Sphingopyxis sp. isolated from Lake Champlain, Canada

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Download	View accepted manuscript: Cyanotoxin degradation activity and mlr gene expression profiles of a Sphingopyxis sp. isolated from Lake Champlain, Canada (PDF, 1 MB)
DOI	Resolve DOI: https://doi.org/10.1039/C6EM00001K
Author	Search for: Maghsoudi, Ehsan; Search for: Fortin, Nathalie¹ ; Search for: Greer, Charles¹ ; Search for: Maynard, Christine; Search for: Pagé, Antoine; Search for: Duy, Sung vo; Search for: Sauvé, Sébastien; Search for: Prévost, Michèle; Search for: Dorner, Sarah
Name affiliation	National Research Council Canada. Energy, Mining and Environment
Format	Text
Type	Article
Journal title	Environmental Science: Processes and Impacts
ISSN	2050-7887 2050-7895
Abstract	A bacterium capable of degrading five microcystin (MC) variants, microcystin-LR, YR, LY, LW and LF at an initial total concentration of 50 μg l−1 in less than 16 hours was isolated from Missisquoi Bay, in the south of Quebec, Canada. Phylogenetic analysis of the 16S rRNA gene sequence identified the bacterium as Sphingopyxis sp., designated strain MB-E. It was shown that microcystin biodegradation activity was reduced at acidic and basic pH values. Even though no biodegradation occurred at pH values of 5.05 and 10.23, strain MB-E was able to degrade MCLR and MCYR at pH 9.12 and all five MCs variants tested at pH 6.1. Genomic sequencing revealed that strain MB-E contained the microcystin degrading gene cluster, including the mlrA, mlrB, mlrC and mlrD genes, and transcriptomic analysis demonstrated that all of these genes were induced during the degradation of MCLR alone or in the mixture of all five MCs. This novel transcriptomic analysis showed that the expression of the mlr gene cluster was similar for MCLR alone, or the mixture of MCs, and appeared to be related to the total concentration of substrate. The results suggested that the bacterium used the same pathway for the degradation of all MC variants.
Publication date	2016-09-20
Language	English
Peer reviewed	Yes
NPARC number	23000814
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Record identifier	b995b58e-a469-4da6-842a-283655e41dfe
Record created	2016-10-14
Record modified	2019-03-08

Date modified:: 2019-05-21

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