Characterisation of a novel DMSP synthesis pathway in marine bacteria (TODD_U17DTP1)

Dimethylsulfoniopropionate (DMSP) is one of the Earth's most abundant organosulfur compounds. It is an antistress compound with key roles in global nutrient and sulfur cycling, signaling and climate. It was thought that only marine eukaryotes produce DMSP, but we have shown that many marine heterotrophic bacteria also produce DMSP. We have identified the first genes for DMSP synthesis in these bacteria allowing this PhD to explore new exciting molecular ventures into how and why microbes produce DMSP.

The PhD: The project will use marine bacteria that produce high cellular levels of DMSP as models to investigate the process. The student will be taught how to grow and study the physiology of model marine bacteria. Using analytical chemistry, they will establish and characterise the bacterial DMSP biosynthetic pathway. Molecular genetics will be used to validate and mutate the key DMSP synthesis genes to confirm their role in this process. The student will study whether environmental conditions affect DMSP production and the transcription of the DMSP synthesis genes to potentially determine the role/s of DMSP in our model bacteria. Finally, using molecular ecology tools, the student will monitor DMSP production, the diversity and abundance of DMSP-producing bacteria and the key bacterial synthesis genes in natural marine environments. For this training will be provided in metagenomics, the use of gene probes and environmental sampling. This PhD will strengthen our ability to assess the effects of e.g., climate change on DMSP cycling, and the significance of bacterial DMSP production.