title: Dimethylsulfoniopropionate biosynthesis in marine bacteria and identification of the key gene in this process.
abstract: Dimethylsulfoniopropionate (DMSP) is one of the Earth's most abundant organosulfur molecules, a signalling molecule1, a key nutrient for marine microorganisms2,3and the major precursor for gaseous dimethyl sulfide (DMS). DMS, another infochemical in signalling pathways4, is important in global sulfur cycling2and affects the Earth's albedo, and potentially climate, via sulfate aerosol and cloud condensation nuclei production5,6. It was thought that only eukaryotes produce significant amounts of DMSP7-9, but here we demonstrate that many marine heterotrophic bacteria also produce DMSP, probably using the same methionine (Met) transamination pathway as macroalgae and phytoplankton10. We identify the first DMSP synthesis gene in any organism, dsyB, which encodes the key methyltransferase enzyme of this pathway and is a reliable reporter for bacterial DMSP synthesis in marine Alphaproteobacteria. DMSP production and dsyB transcription are upregulated by increased salinity, nitrogen limitation and lower temperatures in our model DMSP-producing bacterium Labrenzia aggregata LZB033. With significant numbers of dsyB homologues in marine metagenomes, we propose that bacteria probably make a significant contribution to oceanic DMSP production. Furthermore, because DMSP production is not solely associated with obligate phototrophs, the process need not be confined to the photic zones of marine environments and, as such, may have been underestimated.
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
authors.forename: Andrew R J
authors.initials: AR
authors.lastname: Curson
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.|College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, China.
authors.forename: Ji
authors.initials: J
authors.lastname: Liu
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
authors.forename: Ana
authors.initials: A
authors.lastname: Bermejo Martínez
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
authors.forename: Robert T
authors.initials: RT
authors.lastname: Green
authors.affiliation: School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
authors.forename: Yohan
authors.initials: Y
authors.lastname: Chan
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
authors.forename: Ornella
authors.initials: O
authors.lastname: Carrión
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
authors.forename: Beth T
authors.initials: BT
authors.lastname: Williams
authors.affiliation: Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education; College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
authors.forename: Sheng-Hui
authors.initials: SH
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education; College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.|Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China.
authors.forename: Gui-Peng
authors.initials: GP
authors.lastname: Yang
authors.affiliation: School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
authors.forename: Philip C
authors.initials: PC
authors.lastname: Bulman Page
authors.affiliation: College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, China.|Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China.
authors.forename: Xiao-Hua
authors.initials: XH
authors.lastname: Zhang
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Todd
mesh_terms: D020561:Alphaproteobacteria / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*; D013437:Carbon-Sulfur Lyases / Q000737:chemistry / Q000378:metabolism; D005798:Genes, Bacterial; D054892:Metagenome; D008715:Methionine / Q000096:biosynthesis / Q000378:metabolism; D008780:Methyltransferases / Q000235:genetics* / Q000378:metabolism; D009792:Oceans and Seas; D010802:Phylogeny; D012623:Seawater / Q000737:chemistry / Q000382:microbiology*; D015398:Signal Transduction; D013440:Sulfides / Q000378:metabolism; D013452:Sulfonium Compounds / Q000378:metabolism*
chemical_list: D013440:Sulfides; D013452:Sulfonium Compounds; D008715:Methionine; C068078:dimethylpropiothetin; D008780:Methyltransferases; D013437:Carbon-Sulfur Lyases; C004784:dimethyl sulfide