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

二甲基磺丙酸酯（DMSP）是地球上最丰富的有机硫化合物之一。它是一种抗应激化合物，在全球营养和硫循环、信号和气候中起关键作用。以前认为只有海洋真核生物才能产生DMSP，但我们已经证明许多海洋异养细菌也能产生DMSP。我们已经在这些细菌中确定了DMSP合成的第一个基因，允许本博士探索新的令人兴奋的分子冒险，研究微生物如何以及为什么产生DMSP。博士：该项目将使用产生高水平DMSP的海洋细菌作为模型来研究这一过程。学生将学习如何培养和研究模型海洋细菌的生理。利用分析化学，他们将建立和表征细菌DMSP生物合成途径。分子遗传学将用于验证和突变关键的DMSP合成基因，以确认它们在这一过程中的作用。该学生将研究环境条件是否会影响DMSP的产生和DMSP合成基因的转录，以潜在地确定DMSP在我们的模型细菌中的作用。最后，学生将利用分子生态学工具，监测DMSP的生产、DMSP生产细菌的多样性和丰度以及自然海洋环境中关键细菌合成基因。为此，将提供宏基因组学、基因探针的使用和环境采样方面的培训。这个博士学位将加强我们评估气候变化对DMSP循环的影响的能力，以及细菌DMSP生产的重要性。

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.