My project involves studying the ''Environmental genomics and functional diversity of plant-associated microbial dimethylsulfide degradation in costal salt marshes''.
Dimethylsulfide (DMS) is an atmospheric trace gas that has major implications in the global sulfur cycle. Its atmospheric breakdown products (mainly sulfate and methanesulfonic acid) reflect heat radiation from the sun back into space and therefore have a climate-cooling effect. The atmospheric degradation products of DMS also serve as cloud condensation nuclei (CCN), which support the formation of clouds that reflect further sunlight and thus also contribute to climate cooling [Charlson et al. 1987; Schäfer et al. 2010].
The marine environment represents one of the largest sources of atmospheric DMS, mainly through the degradation of dimethylsulfoniopropionate (DMSP), which represents a key compound in the sulfur cycle. DMSP is produced by a variety of pelagic and benthic microscopic algae as well as by benthic macroscopic algae and salt-tolerant grasses in salt marshes [Liss et al. 1994; Malin and Kirst 1997; Otte et al. 2004].
Previous work has shown that the microbial communities in the phyllosphere of Spartina anglica, a salt-tolerant grass in the salt marsh, also have a considerable potential to degrade DMS, an observation, which represents a previously unrealised aspect of the cycling of DMS in salt marsh environments [Mazard, Schäfer, unpublished].
The aim of the project is to identify microorganisms cycling DMS and their pathways associated with Spartina anglica plants.
More detailed questions of the project are:
1) Are Spartina anglica plants rich in DMSP and is the content of DMSP in Spartina anglica subjected to seasonal or geochemical variations?
2) Do bacterial DMS uptake rates differ in phyllosphere and rhizosphere of Spartina anglica?
3) Which microbial populations are involved in degradation of DMS in phyllosphere and rhizosphere of Spartina anglica?
4) Is there niche differentiation of DMS-degrading microbial populations in the phyllosphere and rhizosphere and are these populations subjected to seasonal variations?
5) Which metabolic pathways contribute to DMS cycling in phyllosphere and rhizosphere of Spartina anglica?
H dot Schaefer at warwick dot ac dot uk