TY - JOUR
T1 - Bacteria are important dimethylsulfoniopropionate producers in coastal sediments
AU - Williams, Beth T.
AU - Cowles, Kasha
AU - Bermejo Martinez, Ana
AU - Curson, Andrew R. J.
AU - Zheng, Yanfen
AU - Liu, Jingli
AU - Newton-Payne, Simone
AU - Hind, Andrew J.
AU - Li, Chun-Yang
AU - Rivera, Peter
AU - Carrion, Ornella
AU - Liu, Ji
AU - Spurgin, Lewis G.
AU - Brearley, Charles A.
AU - Mackenzie, Brett Wanger
AU - Pinchbeck, Benjamin J.
AU - Peng, Ming
AU - Pratscher, Jennifer
AU - Zhang, Xiao-Hua
AU - Zhang, Yu-Zhong
AU - Murrell, J. Colin
AU - Todd, Jonathan D.
PY - 2019/11
Y1 - 2019/11
N2 - Dimethylsulfoniopropionate (DMSP) and its catabolite dimethyl sulfide (DMS) are key marine nutrients, with roles in global sulfur cycling, atmospheric chemistry, signalling and, potentially, climate regulation. DMSP production was previously thought to be an oxic and photic process, mainly confined to the surface oceans. However, here we show that DMSP concentrations and DMSP/DMS synthesis rates were higher in surface marine sediment from e.g., saltmarsh ponds, estuaries and the deep ocean than in the overlying seawater. A quarter of bacterial strains isolated from saltmarsh sediment produced DMSP (up to 73 mM), and previously unknown DMSP-producers were identified. Most DMSP-producing isolates contained dsyB, but some alphaproteobacteria, gammaproteobacteria and actinobacteria utilised a methionine methylation pathway independent of DsyB, previously only associated with higher plants. These bacteria contained a methionine methyltransferase ‘mmtN’ gene - a marker for bacterial DMSP synthesis via this pathway. DMSP-producing bacteria and their dsyB and/or mmtN transcripts were present in all tested seawater samples and Tara Oceans bacterioplankton datasets, but were far more abundant in marine surface sediment. Approximately 108 bacteria per gram of surface marine sediment are predicted to produce DMSP, and their contribution to this process should be included in future models of global DMSP production. We propose that coastal and marine sediments, which cover a large part of the Earth’s surface, are environments with high DMSP and DMS productivity, and that bacteria are important producers within them.
AB - Dimethylsulfoniopropionate (DMSP) and its catabolite dimethyl sulfide (DMS) are key marine nutrients, with roles in global sulfur cycling, atmospheric chemistry, signalling and, potentially, climate regulation. DMSP production was previously thought to be an oxic and photic process, mainly confined to the surface oceans. However, here we show that DMSP concentrations and DMSP/DMS synthesis rates were higher in surface marine sediment from e.g., saltmarsh ponds, estuaries and the deep ocean than in the overlying seawater. A quarter of bacterial strains isolated from saltmarsh sediment produced DMSP (up to 73 mM), and previously unknown DMSP-producers were identified. Most DMSP-producing isolates contained dsyB, but some alphaproteobacteria, gammaproteobacteria and actinobacteria utilised a methionine methylation pathway independent of DsyB, previously only associated with higher plants. These bacteria contained a methionine methyltransferase ‘mmtN’ gene - a marker for bacterial DMSP synthesis via this pathway. DMSP-producing bacteria and their dsyB and/or mmtN transcripts were present in all tested seawater samples and Tara Oceans bacterioplankton datasets, but were far more abundant in marine surface sediment. Approximately 108 bacteria per gram of surface marine sediment are predicted to produce DMSP, and their contribution to this process should be included in future models of global DMSP production. We propose that coastal and marine sediments, which cover a large part of the Earth’s surface, are environments with high DMSP and DMS productivity, and that bacteria are important producers within them.
KW - DMSP
KW - bacteria
KW - marine
KW - salt marsh microbiology
KW - Biogeochemical cycling
U2 - 10.1038/s41564-019-0527-1
DO - 10.1038/s41564-019-0527-1
M3 - Article
VL - 4
SP - 1815
EP - 1825
JO - Nature Microbiology
JF - Nature Microbiology
SN - 2058-5276
ER -