Martinus de Kruijff

Microbial profiling studies of Hydractinia-associated bacteria, analysis of their biosynthetic pathways and engineering of marine bacteria

This PhD thesis will focus on the analysis of secondary metabolites of Hydractinia-associated marine bacteria. Primary focus will be the analysis of biosynthetic gene clusters responsible for production of siderophores in marine Proteobacteria, as a first whole genome sequencing analysis of Hydractinia-associated marine bacteria revealed the presence of several NRPS-PKS-based hybrid cluster regions with unknown product spectrum. As many marine Proteobacteria might not produce siderophores under standard laboratory conditions, different microbiological techniques and biochemical methods will be applied to activate the biosynthetic gene clusters and isolate the predicted siderophores. In parallel, heterologous expression of one candidate cluster env will be pursued, which will be cloned into an expression vector carrying a dual promotor system. Moreover, more detailed comparative genome mining will be used to identify homologous biosynthetic gene clusters in bacteria of different phyla to trace the evolution of these gene clusters, Lastly, fluorescence in situ hybridization (FISH) microscopy of H. echinata polyps will be used to visualize the producing organisms and a targeted metabolomic analysis of the chemosphere of Hydractina to putatively identify natural products of interest.

Supervisor

Christine Beemelmanns

Start of PhD

August 1, 2021

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