Impact of phage microdiversity on marine heterotrophic bacteria – a single cell perspective

• Applicants: Cristina Moraru, Ph.D.; Hryhoriy Stryhanyuk, Ph.D., since 4/2023
• Subject Area: Microbial Ecology and Applied Microbiology
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 464864735

Bacteriophages significantly impact marine bacterial populations and global biogeochemical cycles, through viral lysis, host metabolism manipulation and horizontal gene transfer. Phage infections can have a pronounced effect on the host metabolism. In the time between genome injection and lysis, massive shifts in the bacterial metabolism can take place, such that the infected cell becomes physiologically different from its not-infected counterparts. In the environment, the phage and bacterial host populations are characterized by a high genetic microdiversity. Here, we plan to address the virocell concept from the point of view of phage microdiversity and lytic infection phases, with a focus on marine heterotrophic bacteria and their phages, to enable a better understanding of the viral impact on marine microbial communities. Using a combination of single cell methods and bulk measurements, we aim to answer the following questions: i) are there differences in the virocell metabolism through the various phases of the lytic infection?, ii) to which extent is the phage microdiversity resulting in differences in the virocell metabolism?, and iii) to which extent is the co-infection with multiple microdiverse phages resulting in differences in the virocell metabolism? For this work, we are going to make use of the extensive collection of microdiverse phages and their hosts from the Moraru lab. This collection contains more than 130 phages infecting the environmentally relevant marine Sulfitobacter. Both phages and their host strains are highly related amongst each other, and show a high degree of microdiversity. Method wise, we will use a combination of one-step infection cultures, phage-targeted direct-geneFISH, transcriptomics, stable isotope probing combined with isotope ratio mass spectrometry and nanoSIMS chemical imaging.

• DFG Programme: Priority Programmes
• Subproject of: SPP 2330: New concepts in prokaryotic virus-host interactions - from single cells to microbial communities
• Ehemalige Antragstellerin: Dr. Niculina Musat, until 3/2023