title: Metagenomic identification of bacterioplankton taxa and pathways involved in microcystin degradation in lake erie.
abstract: Cyanobacterial harmful blooms (CyanoHABs) that produce microcystins are appearing in an increasing number of freshwater ecosystems worldwide, damaging quality of water for use by human and aquatic life. Heterotrophic bacteria assemblages are thought to be important in transforming and detoxifying microcystins in natural environments. However, little is known about their taxonomic composition or pathways involved in the process. To address this knowledge gap, we compared the metagenomes of Lake Erie free-living bacterioplankton assemblages in laboratory microcosms amended with microcystins relative to unamended controls. A diverse array of bacterial phyla were responsive to elevated supply of microcystins, including Acidobacteria, Actinobacteria, Bacteroidetes, Planctomycetes, Proteobacteria of the alpha, beta, gamma, delta and epsilon subdivisions and Verrucomicrobia. At more detailed taxonomic levels, Methylophilales (mainly in genus Methylotenera) and Burkholderiales (mainly in genera Bordetella, Burkholderia, Cupriavidus, Polaromonas, Ralstonia, Polynucleobacter and Variovorax) of Betaproteobacteria were suggested to be more important in microcystin degradation than Sphingomonadales of Alphaproteobacteria. The latter taxa were previously thought to be major microcystin degraders. Homologs to known microcystin-degrading genes (mlr) were not overrepresented in microcystin-amended metagenomes, indicating that Lake Erie bacterioplankton might employ alternative genes and/or pathways in microcystin degradation. Genes for xenobiotic metabolism were overrepresented in microcystin-amended microcosms, suggesting they are important in bacterial degradation of microcystin, a phenomenon that has been identified previously only in eukaryotic systems.
authors: Department of Biological Sciences, Kent State University, Kent, Ohio, United States of America. xmou@kent.edu
authors: Xiaozhen
authors: X
authors: Mou
authors: Xinxin
authors: X
authors: Lu
authors: Jisha
authors: J
authors: Jacob
authors: Shulei
authors: S
authors: Sun
authors: Robert
authors: R
authors: Heath
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D000458:Cyanobacteria / Q000145:classification / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D060106:Lakes; D053858:Metabolic Networks and Pathways; D056186:Metagenomics; D052998:Microcystins / Q000378:metabolism*; D058977:Molecular Sequence Annotation; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014871:Water Microbiology
chemical_list: D001426:Bacterial Proteins; D052998:Microcystins; D012336:RNA, Ribosomal, 16S; C078588:microcystin
references: Int J Mol Sci. 2010 Jan 21;11(1):268-87
references: 20162015
references: Toxicon. 2007 Sep 1;50(3):438-41
references: 17498764
references: Appl Environ Microbiol. 1998 May;64(5):1725-30
references: 9572943
references: Water Res. 2008 Feb;42(3):763-73
references: 17761208
references: Appl Environ Microbiol. 2005 Mar;71(3):1405-16
references: 15746343
references: Appl Environ Microbiol. 2006 Jul;72(7):5069-72
references: 16820507
references: Nature. 2008 Feb 7;451(7179):708-11
references: 18223640
references: Environ Microbiol. 2009 Dec;11(12):3189-200
references: 19678830
references: Appl Environ Microbiol. 2009 Nov;75(21):6924-8
references: 19734339
references: Microbiol Mol Biol Rev. 2011 Mar;75(1):14-49
references: 21372319
references: Genome Res. 2007 Mar;17(3):377-86
references: 17255551
references: Appl Environ Microbiol. 2009 Aug;75(15):5167-9
references: 19502429
references: Cell. 2013 Jan 17;152(1-2):39-50
references: 23332745
references: Environ Microbiol. 2004 Dec;6(12):1228-43
references: 15560821
references: ISME J. 2009 Nov;3(11):1314-7
references: 19587772
references: Environ Toxicol. 2001;16(6):523-34
references: 11769251
references: Appl Environ Microbiol. 2006 Jul;72(7):5083-5
references: 16820510
references: BMC Bioinformatics. 2010 Apr 13;11:187
references: 20388221
references: Bioinformatics. 2010 Mar 15;26(6):715-21
references: 20130030
references: Adv Exp Med Biol. 2008;619:105-25
references: 18461766
references: Toxicon. 2010 Jul;55(8):1434-42
references: 20219514
references: J Bacteriol. 1997 Mar;179(5):1431-41
references: 9045797
references: FEMS Microbiol Lett. 2003 Dec 12;229(2):271-6
references: 14680710
references: Ecotoxicol Environ Saf. 2008 Mar;69(3):358-65
references: 17531317
references: Appl Environ Microbiol. 1987 Jun;53(6):1298-303
references: 16347362
references: Evolution. 1989 Jan;43(1):223-225
references: 28568501
references: Appl Environ Microbiol. 1996 Nov;62(11):4086-94
references: 8899999
references: Microb Ecol. 2004 Nov;48(4):567-77
references: 15696390
references: J Hazard Mater. 2010 Aug 15;180(1-3):628-33
references: 20466484
references: N Biotechnol. 2009 Oct 31;26(3-4):205-11
references: 19748604
references: Water Res. 2007 Dec;41(20):4685-95
references: 17640697
references: J Biosci Bioeng. 2012 Dec;114(6):630-4
references: 22883536
references: BMC Bioinformatics. 2006 Mar 20;7:162
references: 16549025
references: Science. 2006 Jun 2;312(5778):1355-9
references: 16741115
references: Environ Microbiol. 2011 Jun;13(6):1632-41
references: 21492362
references: Environ Microbiol. 2005 Dec;7(12):1868-82
references: 16309386