Transfer of killer plasmids between marine Rhodobacterales

Phaeobacter inhibens (light blue) located on Prorocentrum minimum

A team led by Prof. Dr. Jörn Petersen from the Department of Microbial Ecology and Diversity Research was able to show that the horizontal gene transfer of a plasmid gives an otherwise harmless bacterium unexpected abilities. The researchers from the DSMZ, the Helmholtz Institute for Infection Research and the Technical University of Braunschweig published their research results in the renowned journal Microbial Genomics. In their experiments, they were able to demonstrate that the marine bacterium Phaeobacter inhibens is able to kill the dinoflagellate Prorocentrum minimum after ingesting a foreign plasmid. The researchers also showed that the uptake of the ring-shaped DNA molecule leads to a complete genetic reprogramming of the organism. Without the killer plasmid, both partners live in symbiotic harmony, with the marine bacterium promoting the growth of the alga by producing vitamins.

For more information see
Tomasch J., Ringel, V., Wang H., Freese H.M., Bartling, P., Brinkmann, H., Vollmers, J., Jarek, M., Wagner-Döbler, I., Petersen, J. (2022) Fatal affairs – conjugational transfer of a dinoflagellate-killing plasmid between marine Rhodobacterales. Microb Genom. 2022 Mar;8(3).
doi: 10.1099/mgen.0.000787