Understanding the factors that determine functional stability of bacterial communities in the face of environmental changes

• Applicant: Anna Weiß
• Subject Area: Microbial Ecology and Applied Microbiology
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 551586756

Bacterial communities are highly prevalent in many of Earth’s ecosystems and take on crucial roles by facilitating important biological functions. The manifold contributions of bacterial communities span nearly all ecosystems and numerous applications, and affect biogeochemical processes and human health, as well as food production, waste and water management. Because of their importance, the disruption of bacterial functions can result in drastic changes or even the collapse of the ecosystems that rely on the bacterial communities. Interestingly, even though most ecosystems frequently experience environmental perturbations in parameters essential to bacterial life, bacterial community functions often remain stable. Which ecological factors and community characteristics shape and affect the stable realization of biological functions by bacterial communities despite perturbations in their environment is a central knowledge gap in bacterial ecology. Understanding the mechanisms at play is crucial not only to maintain natural communities upon changes in environmental conditions, but also to manage, rationally manipulate, or de novo assemble functionally stable communities for environmental, industrial or medical applications. Ecological theory suggests that functional stability in bacterial communities can emerge from functional redundancy. In communities with high functional redundancy, redundantly encoded functions are thought to be maintained even if the composition of species changes upon an external perturbation. While theoretically well-described, the effect of functional redundancy on functional stability is experimentally not well explored. With the proposed work, I aim to address this knowledge gap and study the role of functional redundancy for functional stability comprehensively and with explicit focus on its consequences for bacterial community ecology. I aim to establish an experimentally supported, consolidated understanding on how functional stability is affected by key ecological characteristics of bacterial communities, going beyond predominantly theoretical discussions and with explicit focus on the multidimensionality of ecological parameters. Explicitly, the overall goal of the outline project is to dissect the link between functional redundancy and bacterial community assembly and interactions in a quantitative way, determine and mechanistically resolve the effect of these community features on functional stability and map out the underlying dynamics across environmental parameters. Investigating community resilience and mechanisms affecting microbial community composition and function of bacterial communities will provide valuable insights into what shapes, sustains, and defines microbial systems – a pivotal goal given the crucial role of bacterial communities for global biogeochemical processes and human health.

• DFG Programme: WBP Fellowship
• International Connection: Switzerland
• Host: Professor Dr. Martin Ackermann