| Title | Salinity as a Regulator of DMSP Degradation in Ruegeria pomeroyi DSS-3 |
|---|---|
| Author | Paula Salgado1*, Ronald Kiene2, William Wiebe3, and Catarina Magalhães1 |
| Address | 1EcoBioTec Laboratory, Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Rua dos Bragas 289, P 4050-123 Porto, Portugal, 2Department of Marine Sciences, University of South Alabama; 5871 USA Drive North, Mobile, Alabama, USA 36688 and Dauphin Island Sea Lab, Dauphin Island, Alabama 36528, USA, 3Department of Marine Sciences; University of Georgia, Athens, GA 30602, USA |
| Bibliography | Journal of Microbiology, 52(11),948-954, 2014, |
| DOI | 10.1007/s12275-014-4409-1 |
| Key Words | Ruegeria pomeroyi, DMSP degradation, salinity effect, dimethyl sulfide, methanethiol |
| Abstract | Dimethylsulfoniopropionate (DMSP) is an important carbon and sulfur source to marine bacterial communities and the main precursor of dimethylsulfide (DMS), a gas that influences atmospheric chemistry and potentially the global climate. In nature, bacterial DMSP catabolism can yield different proportions of DMS and methanethiol (MeSH), but relatively little is known about the factors controlling the pathways of bacterial degradation that select between their formation (cleavage vs. demethiolation). In this study, we carried out experiments to evaluate the influence of salinity on the routes of DMSP catabolism in Ruegeria pomeroyi DSS-3. We monitored DMS and MeSH accumulation in cell suspensions grown in a range of salinities (10, 20, 30 ppt) and with different DMSP amendments (0, 50, 500 μM). Significantly higher concentrations of DMS accumulated in low salinity treatments (10 ppt; P < 0.001), in both Marine Basal Medium (MBM) and half-strength Yeast Tryptone Sea Salts (½ YTSS) media. Results showed a 47.1% and 87.5% decrease of DMS accumulation, from salinity 10 to 20 ppt, in MBM and ½ YTSS media, respectively. On the other hand, MeSH showed enhanced accumulations at higher salinities (20, 30 ppt), with a 90.6% increase of MeSH accumulation from the 20 ppt to the 30 ppt salinity treatments. Our results with R. pomeroyi DSS-3 in culture are in agreement with previous results from estuarine sediments and demonstrate that salinity can modulate selection of the DMSP enzymatic degradation routes, with a consequent potential impact on DMS and MeSH liberation into the atmosphere. |