Congratulations, Dr. Schwarzhans!
Angelika Schwarzhans successfully defended her PhD thesis on May 7, 2026.
The thesis focused on environmental chlamydiae and aimed to demonstrate their value as model systems for diverse host–microbe interactions and as environmentally important members of microbial communities. To this end, the author investigated both a novel chlamydial species found in the freshwater predator Hydra and the effects of known chlamydial species on a soil ecosystem. Through an in-depth analysis of the physical association and genomic adaptations to its Hydra host, the study uncovered tissue-specific localization and ongoing genomic adaptation in the form of genomic rearrangements and gene disruptions. Additionally, the work provides evidence that chlamydiae can influence a soil ecosystem by shifting their host's abundance and behavior, leading to changes in bacterial community composition and ecosystem-wide effects. Together, these studies illustrate the evolutionary success of the chlamydial core genome and position bacterial endosymbionts not only as important components of their hosts but also as regulators of broader microbial communities and processes.
CeMESS\Sandra Montano