Assoz.-Prof. Dr. Jillian Petersen

Portrait of Jillian Petersen
Associate Professor
WWTF Vienna Research Group Leader
University of Vienna
Department of Microbiology and Ecosystem Science
Division of Microbial Ecology
Djerassiplatz 1
A-1030 Vienna
Phone: +43 1 4277 91206

Complete publication list

For Jillian's CV see below (bottom of page)

Symbiosis Research:

Every plant and animal, including humans, evolved in a ‘sea’ of microbes. Animal-microbe mutualisms are ubiquitous in nature and are powerful driving forces in the evolution of life on Earth. Most animal-associated microbial communities are enormously diverse, which poses an immense challenge to understanding the molecular crosstalk that underpins establishment and maintenance of these lifelong partnerships. Many marine invertebrates have evolved intimate associations with just one or a few species of chemosynthetic bacteria. They are therefore ideal natural models for investigating the fundamental mechanisms that underpin host-microbe associations.

400 Million Years of Symbiosis: Marine Lucinid Clams and their Sulfur-oxidizing Symbionts

We investigate host-microbe mutualisms in diverse host animal groups, but our main experimental models are lucind clams that host a specific species of sulfur-oxidizing bacteria in their gill cells. Lucinid clams are found worldwide in shallow marine habitats such as coastal seagrass sediments that are easily accessible for sampling. There are hundreds of species of lucinids currently known, and almost every one of these hosts its own specific symbiotic microbes. The symbiotic bacteria are chemosynthetic, which means they use chemical energy from the environment to synthesize sugars and other molecules needed by the host. This ancient and highly successful partnership has resulted in a reduction of the length and complexity of the clam’s digestive tract over evolution, as it relies on its gill symbionts for nutrition.


Research topics:

  • Genomic mechanisms underpinning host-microbe interactions
  • Evolution of host-microbe interactions
  • Host-microbe-environment interactions
  • Influence of hosts and symbionts on nutrient cycling in coastal habitats
  • Fundamental research on terrestrial root nodule symbioses
  • In situ imaging of symbiont identity and activity


Current and recent research projects:

400 Million Years of Symbiosis: Host-microbe interactions in marine lucinid clams from past to present (EvoLucin)

WWTF VRG Molecular Host-Microbe Interactions

FWF Cluster of Excellence Microbiomes Drive Planetary Health

BiOcean5D: Marine Biodiversity Assessment and Prediction Across Spatial, Temporal and Human Scales

Lucinid symbiosis genomics hub

MAINTAIN PhD Program in Symbiosis



Courses taught by Jillian Petersen at the University of Vienna


Joining the lab:

Information on open research positions can be found here. If you are interested in joining our team with your own fellowship, please check out our PhD & postdoc program and get in touch with Jill for details.