Brandon Seah: Farming or recycling? The nutritional symbiosis of the ciliate Kentrophoros with sulfide-oxidizing bacteria

Seminar, Mikrobiologi

13.04.2018 | Anne Kirstine Mehlsen

Dato man 14 maj
Tid 15:00 17:00
Sted Institut for Bioscience, Ny Munkegade 114-116, bygning 1540-116

Foredragsholder: Brandon Seah, MPI for Marine Microbiology, Bremen



Kentrophoros is a diverse clade of microbial eukaryotes from marine sediments, always found with a dense “coat” of symbiotic, sulfur-oxidizing (thiotrophic) bacteria. These are a distinct lineage of Gammaproteobacteria, and are harvested by the host for food. Unexpectedly, while the symbiont genomes encode pathways for oxidizing reduced sulfur, they lack any of the known pathways for autotrophic CO2 fixation. Instead have the genetic potential to assimilate organic carbon to produce biomass lithoheterotrophically, possibly using both substrates from the environment and host fermentative waste. Although many chemosynthetic symbioses are known to be mixotrophic, this is the first symbiont found to lack genes for canonical autotrophic metabolism. This highlights how heterotrophy and waste recycling may be just as important to nutritional symbioses as autotrophic production.

Institut for Bioscience, Offentligheden / Pressen, Medarbejdere, Mikrobiologi