Periodic Reporting for period 2 - EcoLipid (Ecophysiology of membrane lipid remodelling in marine bacteria)
Reporting period: 2018-10-01 to 2020-03-31
1) comparative lipidomics experiments using Ruegerial pomeroyi as the model and the identification of the novel glutamine-containing lipids in this bacterium and its role in the adaptation to phosphorus stress. This work has recently been accepted in publication in the ISME Journal (Smith et al., 2019).
2) Mechanistic insight into lipid remodelling. We have successfully generated several mutants, including plcP, olsAB, glsB which will be used in this work package. We have recently obtained a novel mutant involved in the production of a new homotaurin containing lipids in marine roseobacteris. This new lipid has not been reported previously in any live organisms. This manuscript for reporting the identification is currently under preparation to be submitted to ISME Journal. We have also successfully tested the methodology of isotope labelling using radio-active compounds. Furthermore, we have also purified and biochemically characterised the key enzyme PlcP which is essential in lipid remodelling. this work has recently been published in Applied and Environmental Microbiology (Wei et al., 2018).
3) We have successfully isolated several bacterial phages which infect our model bacteria. This will be used to understand the role of remodelling in phage interaction. We have tested infection dynamics of phage against our model bacterium DSS3 and analysed lipidomics changes and proteomics changes between wild-type and mutants. Two of the phages infecting Roseobacter pomeryo DSS-3 have unexpected DNA substitution from thymidine by deoxyuridine (dU) and do not resemble anything else in the current bacteriophage genome database. We have established that they form a novel family of bacterial virus. This student is currently under review for publication (Branko et al.)
4) We have successfully obtained several eukaryotes and managed to maintain and grow them successfully in the laboratory. We are currently investigating the interaction between wild type Roseobacter strains and the lipid remodelling mutants.