We isolated two new soil bacteria: ONC3T (from garden soil in NC, USA; LMG 31738T=NRRL B-65553T) and M1T (from farmed soil in MI, USA; NRRL B-65551T=ATCC TSD-197T=LMG 31739T) and characterized their metabolic phenotype based on Biolog, MALDI-TOF MS and fatty acid analyses, and compared 16S rRNA and whole genome sequences to other members of the Oxalobacteraceae after sequencing on an Illumina Nextera platform. Based on the results of 16S rRNA sequence analysis, ONC3T shows the highest sequence similarity to Massilia solisilvae J18T (97.8 %), Massilia terrae J11T (97.7 %) and Massilia agilis J9T (97.3 %). Strain M1T is most closely related to Noviherbaspirillum denitrificans TSA40T, Noviherbaspirillum agri K-1-15T and Noviherbaspirillum autotrophicum TSA66T (sequence identity of 98.2, 98.0 and 97.8 %, respectively). The whole genome of ONC3T has an assembled size of 5.62 Mbp, a G+C content of 63.8 mol% and contains 5104 protein-coding sequences, 56 tRNA genes and two rRNA operons. The genome of M1T has a length of 4.71 MBp, a G+C content of 63.81 mol% and includes 4967 protein-coding genes, two rRNA operons and 44 tRNA genes. Whole genome comparisons identified Massilia sp. WG5 with a 79.3 % average nucleotide identity (ANI) and 22.6 % digital DNA-DNA hybridization (dDDH), and Massilia sp. UBA11196 with 78.2 % average amino acid identity (AAI) as the most closely related species to ONC3T. M1T is most closely related to N. autotrophicum TSA66T with an ANI of 80.27 %, or N. denitrificans TSA40T with a dDDH of 22.3 %. The application of community-accepted standards such as <98.7 % in 16S sequence similarity and <95-96 % ANI or 70 % DDH support the classification of Massilia horti ONC3T and Noviherbaspirillum arenae M1T as novel species within the Oxalobacteraceae.
Keywords: Massilia; Noviherbaspirillum; Oxalobacteraceae; plant-growth promoting rhizobacteria.