Simplifying the complexity of the soil microbiome to guide the development of next-generation SynComs

Introduction: Microbial synthetic communities (SynComs) are commonly commercialised to improve crop yield and restoration outcomes. However, many times, these SynComs are over-simplistic and are far from being able to unleash the soil microbiome's full potential. This is partially due to the fact that harnessing the full potential of the soil microbiome to fuel new SynComs is highly complex. Materials and Methods: Here, I used a multidisciplinary approach combining data from a global grassland field survey and ecological theory with satellite-based measurements for aboveground biomass and ‘omics’ to provide an example of how to connect the soil microbiome of real-world ecosystems with the development of the next generation of SynComs. The same approach could be used to identify individual taxa associated with plant productivity within and across any ecosystem type from local to global scales. Results: I used a three-step approach (#1 Dominant taxa + #2 correlation networks + #3 microbe-function) aiming at identifying individual soil taxa with the potential to promote plant production across contrasting environments. This approach simplified the complexity of the soil microbiome to 0.4% of all investigated taxa, which were positively associated with plant productivity after statistically accounting for other key environmental factors. These taxa are common, ubiquitous and native across contrasting global grasslands, suggesting that they could be used under different soil and climatic conditions, and potentially, under different climate change scenarios. Finally, this study further provides a list of soil taxa associated with high and low productive grassland ecosystems globally. Conclusion: The multidisciplinary approach presented here, along with the use of SynComs, can help unlock the soil microbiome's full potential when aiming to support food production and the restoration of ecosystems under global change.