Harnessing Emergent Properties of Microbial Consortia: Assembly of the Xilonen SynCom

Synthetic communities (SynComs) are valuable tools for addressing fundamental questions in microbial ecology regarding community assembly. They could also potentially aid in successfully manipulating microbial communities for clinical, biotechnological, and agricultural applications. SynCom design is complicated since interactions between microbes cannot be predicted based on their individual properties. Here, we aimed to assemble a higher-order SynCom from seed-endophytic bacteria isolated from native maize landraces. We screened co-cultures that included strains from the Bacilli class, and the Burkholderia and Pseudomonas genera since these taxa have been previously shown to be important for the fertility of native maize landraces. We developed a combinatorial, bottom-up strategy aimed at the detection of a complex colony architecture as an emergent collective property. Using this simplified approach, we assembled a SynCom composed of Bacillus pumilus NME155, Burkholderia contaminans XM7 and Pseudomonas sp. GW6. The strains exhibited positive and negative interactions when evaluated in pairs, but their higher-order assembly results in a complex colony architecture, which is considered a proxy of biofilm formation. This SynCom was named Xilonen after the Aztec goddess of young maize and fertility. The Xilonen SynCom will aid in studying the molecular and ecological basis mediating maize fertility.