We are recruiting!
Post Doc Position available for one year with the option to extend
The applicant should have profound competence in bioinformatic analyses of metatranscriptomes and bacterial (and animal) physiology. Knowledge in marine biology and symbioses are of advantage. Very good knowledge of English in writing and speaking is required. Ability to work in teams is required. if you are interested send your application to monika.bright(at)univie.ac.at Applications should include a CV, a brief statement of technical skills, research experiences and interests, and contact information for at least two academic referees.
NEW FUNDED PROJECT: Candidatus Endoriftia persephone response to host-associated and free-living life style
One of the most exiting mutualisms is the association between the sulfur-oxidizing bacterium, Candidatus Endoriftia persephone, and its host Riftia pachyptila. These giant tubeworms live in the deep sea at hydrothermal vents in the Pacific Ocean. The tubeworms reproduce through larvae that do not carry the symbionts. They migrate through the seawater and settle at vents. There, the uptake of the symbiont into the host happens in each host generation anew from a pool of free-living symbionts from the environment. The host has no mouth and gut as adult and is nourished by its symbiont, housed in an organ deep inside the host body. The symbionts receive all chemicals necessary for chemoautotrophy. In return they feed the host. The tubeworms, however, are highly dependent on the environment in which sulfide and oxygen fluctuate. How the symbiont reacts to variable concentrations is not known yet. Upon cessation of vent flow, supplies of chemicals stop and the host dies. The symbionts, however survive because they leave the dead host. How they manage is not known yet.
The overall goal of this project is to investigate the molecular response of host-associated and free-living life style in Endoriftia using metatransciptomics. In specifics, we will study in a suite of experiments how Endoriftia reacts to hosts differing in cooperativeness, to a dead host, and to deep-sea conditions when free-living.
The struggle to survive
Instead of taking up food with the mouth, little gutless tubeworms house sulfur bacteria in their body. They pick them up from the environment as soon as they settle on rocks after dispersing as larvae in the water. Tubeworms provide shelter for the bacteria. They feed their symbionts with inorganic gases so that they can grow like plants on land. In return the symbionts provide food to the tubeworm host so that they grow and reproduce in the absence of a digestive system. Both partners benefit from each other in this mutualistic relationship. However, life may be short because vent fluid eventually ceases. What happens to the bacteria after a tubeworm dies? They are trapped in a dead body that decays without gases to sustain autotrophic growth. Not to die with their host, the symbionts must leave the dead tubeworm.
How they manage we study in high-pressure aquaria where we incubate live symbionts in dead host tissue. We offer them food like sugar to investigate whether they can switch to a heterotroph life style during their escape. Such experiments were done during the cruise to the East Pacific Rise with the research vessel Atlantis and collecting samples with the submersible Alvin in October 2016.
Go to the blog in facebook hydrothermal vent for more details.
What do anemone, shipworms, roundworms and clams have in common?
The first course in Marine Microbial Symbiosis took place at the Institute of Marine Biology in Piran, Slovenia in July 2016. Supported by the teachers Monika Bright and Silvia Bulgheresi, the tutor Lukas Schuster and the PhD students Gabriela Paredes and Salvador Espada Hinojosa, the eleven students of the course investigate four different symbioses: the anemone Anemonia viridis and its photoautotrophic microalgae, the shipworm Teredo navalis and its nitrogen-fixing bacteria, a newly discovered stilbonematinae roundworm Eubostrichus sp. and its chemoautotrophic ectosymbionts, and the clam Loripes lacteus and its chemoautotrophic endosymbionts.
To follow the course, go to facebook – hydrothermal vent
Julia Klose completes her PhD
Julia Klose defended her Ph.D. thesis successfully on March, 26, 2016. Congratulations!
Prof. Horst Felbeck from Scripps Institution of Oceanography, San Diego, Prof. François Lallier from SNRS UPMC Station Biologique Roscoff, and Dr. Silvia Bulgheresi from the University of Vienna were the examiners of her thesis committee headed by the study program director Prof. Walter Jäger.
She has moved on to Dr. Jillian Petersen lab, Forschungsverbund Chemistry meets Microbiology, as postdoc to work on the lucinid clam symbiosis. Since her new lab is located in the same building, fortunately we still see her often.