Non-nodule forming bacteria-
We were also able to recover a diversity of non-nodule forming species of bacteria. The most abundant taxa in our collection areBacillus and Micromonospora, two genera that are commonly found associated with nodules (Trujillo et al. 2010, De Meyer et al. 2015). Bacillus is potentially the most common nodule-associated bacteria (Xu et al. 2014). Nodule-associated Bacillus are important constituents of the nodule microbiome, solubilizing phosphate (Tapia-García et al. 2020), promoting nodulation (Chinnaswamy et al. 2018), and enhancing plant size (Bai et al. 2002). Similarly,Micromonospora is commonly found in the nodule microbiome. In one study Micromonospora was found in 50% of Trifolium andMedicago nodules examined (Benito et al. 2017). Micromonospora has been described as a rhizobia-helper bacteria because of its ability to enhance nodulation and improve nitrogen use by plants (Martínez-Hidalgo et al. 2014). In future work, would like to use assays to check for siderophore production (Ahmad et al. 2008), IAA production (Loper and Schroth 1986), and phosphate solubilization(Ahmad et al. 2008). These functions are typically correlated with plant growth promotion. Finally, we will inoculate Medicago lupulina to check plant-growth promotion with candidate strains.