Towards predictive assembly of stable, self-sustaining cyanobacterial communities par Orkun Soyer

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Abstract: Cyanobacteria were the first organisms - as far as we can tell – to have altered drastically the entire planet’s chemical makeup. By utilising photosynthesis, they have oxygenated Earth’s atmosphere. This process, along with many other microbial metabolic conversions are still having a global impact today. In the oceans, for example, cyanobacteria are estimated to be responsible for about third to half of total productivity. No microbial process, however, takes place in isolation but rather in microbial communities of many interacting species. Here, we ask how cyanobacteria interact with other bacteria to form communities and what factors influence these communities composition – in terms of species and metabolic functions - and their “stability”? Considering that many cyanobacterial communities in Nature form spatial organisation, we also ask how such organisation emerges and how it impacts metabolic processes? From studying these questions using nature-derived laboratory systems, we hope to gather insights that can allow us to undertake predictable assembly of cyanobacterial communities. In particular, we are interested in developing self-sustaining cyanobacterial communities as microbial model systems of the biosphere and as biotechnological platforms for bioproduction and carbon capture.
In this talk, I will summarize our recent and ongoing results.  We have been utilising “laboratory enrichment” experiments involving sub-culturing of environmental samples in photoautotrophic media. These experiments reveal that cyanobacteria always associate with specific heterotrophic bacteria, which are more strongly determined by their metabolic functions than their taxonomic identity. We find that the assembly process leading to such cyanobacteria-heterotroph communities involves a strong influence from the environment but also factors emerging from within community activities. We show that on such emergent factor that can influence community composition and function is formation of spatial organisation in the form of mm-to-cm scale aggregates. We found that such macro-scale spatial organisation can be driven solely by the gliding motility of filamenteous cyanobacteria and an interplay of physics of movement with biological and abiotic processes. I will end the talk with a discussion of our ongoing efforts, revolving around better characterising the dynamics of final metabolic outputs of Cyano-Heterotroph communities – that is CO2 and O2 - and developing microbial closed ecosystems that could become models for planetary science and microbial ecology.

Relevant publications:
https://academic.oup.com/ismej/article/19/1/wraf126/8168964
https://elifesciences.org/reviewed-preprints/100768
https://www.biorxiv.org/content/10.64898/2026.02.11.705344v1
 

Biography: Orkun Soyer is a professor at the University of Warwick, School of Life Sciences and a Gordon and Betty Moore Investigator. His current research focusses on (1) cellular metabolism and understanding the dynamics of metabolic overflows, and (2) spatial and temporal organisation in microbial communities. His group utilizes both modelling and experiments and comprises students and early career researchers with backgrounds in biology, chemistry, physics, and mathematics. Among other techniques, his group uses different modalities of time-lapse fluorescent microscopy, most recently to follow cellular NADH dynamics and spatial organisation through filamentous cyanobacterial motility.

Orkun holds a Phd in chemistry from the University of Michigan, for his work on protein evolution with Dr. Richard Goldstein. After a postdoctoral research on evolution of structure and dynamics of biochemical, cellular networks with Dr. Sebastien Bonhoeffer, at the ETH, Zurich, Orkun started his own research group at the Microsoft Research Centre for Computational Biology in Trento, Italy. He subsequently held lecturer and senior lecturer positions at the University of Exeter, before joining University of Warwick as a professor in 2013.

More information about Orkun: https://warwick.ac.uk/fac/sci/lifesci/research/osslab/