The abundant marine bacterium Pelagibacter simultaneously catabolizes dimethylsulfoniopropionate to the gases dimethyl sulfide and methanethiol
De Leenheer, P
Nature Publishing Group
© 2016 Macmillan Publishers Limited, part of Springer Nature.
Marine phytoplankton produce ∼109 tonnes of dimethylsulfoniopropionate (DMSP) per year1,2, an estimated 10% of which is catabolized by bacteria through the DMSP cleavage pathway to the climatically active gas dimethyl sulfide3,4. SAR11 Alphaproteobacteria (order Pelagibacterales), the most abundant chemo-organotrophic bacteria in the oceans, have been shown to assimilate DMSP into biomass, thereby supplying this cell's unusual requirement for reduced sulfur5,6. Here, we report that Pelagibacter HTCC1062 produces the gas methanethiol, and that a second DMSP catabolic pathway, mediated by a cupin-like DMSP lyase, DddK, simultaneously shunts as much as 59% of DMSP uptake to dimethyl sulfide production. We propose a model in which the allocation of DMSP between these pathways is kinetically controlled to release increasing amounts of dimethyl sulfide as the supply of DMSP exceeds cellular sulfur demands for biosynthesis.
s. J.S. acknowledges China Scholarships Council (CSC) for financial support. Major support was provided by a grant from the Marine Microbiology Initiative of the Gordon and Betty Moore Foundation (grant no. GBMF607.01 to S.J.G.). Proteomics measurements were supported by the US Department of Energy’s (DOE) Office of Biological and Environmental Research (OBER) Pan-omics programme at Pacific Northwest National Laboratory (PNNL) and performed in the Environmental Molecular Sciences Laboratory, a DOE OBER national scientific user facility on the PNNL campus. A.W.B.J. and J.D.T. were supported by grant no. NE/H008586/1 from the UK Natural Environment Research Council and E.K.F. was supported by a studentship from the Tyndall Centre at the University of East Anglia. Funds for the PTR-TOF were provided by NASA (grant no. NNX15AE70G to K.H.H. and S.J.G.) and by a grant to K.H.H. from the Oregon State University Research Office. This research was supported by the US National Science Foundation (grant OCE-1436865).
This is the author's accepted manuscript.
Final version available from Nature via the DOI in this record.
Vol. 1, article 16065