Linking DMSP cycling and growth in abundant and important marine bacteria

TODD_U23DTP

Billions of tonnes of osmolyte dimethysulfonioproprionate (DMSP) are produced annually in Earth’s oceans by many algae and bacteria.

These organisms produce DMSP at mM intracellular concentrations for protection against varied stresses. When released into the environment, microorganisms import and catabolise DMSP to generate the climate-cooling gas and potent signalling molecule dimethylsulfide (DMS) via DMSP lyase enzymes. Intriguingly, some microorganisms that expend energy to produce DMSP also lyse DMSP, but it is unclear why or how these processes are regulated at the molecular, physiological and environmental levels. These are the key questions this PhD seeks to answer.

To address these important questions the PhD will study Labrenzia, a model Rhodobacterales (abundant in marine environments) that makes and lyses DMSP.
Furthermore, we have evidence linking DMSP cycling to the fundamental process of cell growth and division in Labrenzia, which will also be investigated and may enlighten on the function of DMSP.

You will join well-resourced and vibrant labs that provided step changes to the understanding of DMSP cycling and bacterial cell division and growth.
Expert multidisciplinary training will be provided in analytical chemistry techniques to monitor DMSP cycling; molecular microbiology technologies, e.g., generation of knockout mutations and fluorescent promoter and protein fusions to study the expression and cellular localisation of DMSP cycling enzymes and cytoskeletal proteins controlling growth; and in environmental microbiology.

You will discuss your findings at weekly team and supervisory meetings, where your progress will be monitored and training needs assessed. You will attend and present work at high-profile national and international scientific conferences, which will aid your writing of peer-reviewed scientific publications and your PhD thesis.

We are looking for a highly motivated applicant with strong interests in molecular microbiology and who can thrive in a multidisciplinary research laboratory.

References

1. Curson ARJ, Todd, JD, Sullivan MJ and Johnston AWB (2011). Catabolism of dimethylsulfoniopropionate: microorganisms, enzymes and genes. Nature Reviews Microbiology 9: 849-859.

2. Williams BT, Cowles K, Bermejo Martínez A, Curson ARJ, Zheng Y, Liu J, Newton-Payne S, Hind AJ, Li CY, Rivera PPL, Carrión O, Liu J, Spurgin LG, Brearley CA, Wagner Mackenzie B, Pinchbeck BJ, Peng M, Pratscher J, Zhang XH, Zhang YZ, Murrell JC & Todd JD. (2019). Nature Microbiology, 4 (11), 1815-1825.

3. Curson ARJ, Williams BT, Pinchbeck BJ, Sims LP, Martínez AB, Rivera PPL, Kumaresan D, Mercadé E, Spurgin LG, Carrión O, Moxon S, Cattolico RA, Kuzhiumparambil U, Guagliardo P, Clode PL, Raina JB, Todd JD. (2018). DSYB catalyses the key step of dimethylsulfoniopropionate biosynthesis in many phytoplankton. Nature Microbiology. 4: 430-439.

4. Holmes NA, Walshaw J, Leggett RM, Thibessard A, Dalton KA, Gillespie MD, Hemmings AM, Gust B, Kelemen GH. (2013). Coiled-coil protein Scy is a key component of a multiprotein assembly controlling polarized growth in Streptomyces. PNAS, 110: E237-406.

5. Kelemen GH (2017). Intermediate filaments supporting cell shape and growth in bacteria. “Prokaryotic Cytoskeletons, Subcellular Biochemistry 84, edited by Prof. Jan Löwe and Prof. Linda Amos. p161-211.