Microbial community engineering using coalescence events

Microbial community engineering is an emerging and promising biotechnology with broad potential applications, such as the bioremediation of contaminated environments. A key advantage of this approach is the possibility to design multifunctional communities using the coalescence framework. Our objective was to determine key features of the coalesced communities, as well as the importance of the choice of the parental communities that would yield the best multifunctional communities capable of degrading several xenobiotics. For this purpose, we experimentally mixed communities degrading two different xenobiotics: the herbicide isoproturon and the antibiotic sulfamethazine. We analysed the community composition before and after coalescence as well as their degradation capacities. The results highlight the need to maintain selection pressure through the presence of the targeted molecule during the coalescence event, at least for sulfamethazine. The performance of both parental communities as well as the compositional distance between them emerged as important features. Furthermore, co-occurrence networks inferred from coalescence outcomes revealed that these coalescence events were modular, with limited new interactions between the two parental communities. Finally, degradation performances of the best coalesced communities were equivalent to those of both parental communities, confirming the relevance of this approach.