Jump to main content
Jump to site search

Issue 11, 2016
Previous Article Next Article

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

Author affiliations

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.

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

Back to tab navigation
Please wait while Download options loads

Supplementary files

Publication details

The article was received on 01 Jan 2016, accepted on 13 Sep 2016 and first published on 20 Sep 2016


Article type: Paper
DOI: 10.1039/C6EM00001K
Citation: Environ. Sci.: Processes Impacts, 2016,18, 1417-1426
  •   Request permissions

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

    E. Maghsoudi, N. Fortin, C. Greer, C. Maynard, A. Pagé, S. V. Duy, S. Sauvé, M. Prévost and S. Dorner, Environ. Sci.: Processes Impacts, 2016, 18, 1417
    DOI: 10.1039/C6EM00001K

Search articles by author