BioSciences

The type strain of the prospective 10.1601/nm.30737 sp. nov. ERR11^T, was isolated from a nodule of the leguminous tree Erythrina brucei native to Ethiopia. The type strain 10.1601/nm.1463 10.1601/strainfinder?urlappend=%3Fid%3DCCBAU+10071 ^T, was isolated from the nodules of Lespedeza cuneata in Beijing, China. The genomes of ERR11^T and 10.1601/strainfinder?urlappend=%3Fid%3DCCBAU+10071 ^T were sequenced by DOE-JGI and deposited at the DOE-JGI genome portal as well as at the European Nucleotide Archive. The genome of ERR11^T is 9,163,226 bp in length and has 102 scaffolds, containing 8548 protein-coding and 86 RNA genes. The 10.1601/strainfinder?urlappend=%3Fid%3DCCBAU+10071 ^T genome is arranged in 108 scaffolds and consists of 8,201,522 bp long and 7776 protein-coding and 85 RNA genes. Both genomes contain symbiotic genes, which are homologous to the genes found in the complete genome sequence of 10.1601/nm.24498 10.1601/strainfinder?urlappend=%3Fid%3DUSDA+110 ^T. The genes encoding for nodulation and nitrogen fixation in ERR11^T showed high sequence similarity with homologous genes found in the draft genome of peanut-nodulating 10.1601/nm.27386 10.1601/strainfinder?urlappend=%3Fid%3DLMG+26795 ^T. The nodulation genes nolYA-nodD2D1YABCSUIJ-nolO-nodZ of ERR11^T and 10.1601/strainfinder?urlappend=%3Fid%3DCCBAU+10071 ^T are organized in a similar way to the homologous genes identified in the genomes of 10.1601/strainfinder?urlappend=%3Fid%3DUSDA+110 ^T, 10.1601/nm.25806 10.1601/strainfinder?urlappend=%3Fid%3DUSDA+4 and 10.1601/nm.1462 10.1601/strainfinder?urlappend=%3Fid%3DCCBAU+05525. The genomes harbor hupSLCFHK and hypBFDE genes that code the expression of hydrogenase, an enzyme that helps rhizobia to uptake hydrogen released by the N₂-fixation process and genes encoding denitrification functions napEDABC and norCBQD for nitrate and nitric oxide reduction, respectively. The genome of ERR11^T also contains nosRZDFYLX genes encoding nitrous oxide reductase. Based on multilocus sequence analysis of housekeeping genes, the novel species, which contains eight strains formed a unique group close to the 10.1601/nm.25806 branch. Genome Average Nucleotide Identity (ANI) calculated between the genome sequences of ERR11^T and closely related sequences revealed that strains belonging to 10.1601/nm.25806 branch (10.1601/strainfinder?urlappend=%3Fid%3DUSDA+4 and 10.1601/strainfinder?urlappend=%3Fid%3DCCBAU+15615), were the closest strains to the strain ERR11^T with 95.2% ANI. Type strain ERR11^T showed the highest DDH predicted value with 10.1601/strainfinder?urlappend=%3Fid%3DCCBAU+15615 (58.5%), followed by 10.1601/strainfinder?urlappend=%3Fid%3DUSDA+4 (53.1%). Nevertheless, the ANI and DDH values obtained between ERR11^T and 10.1601/strainfinder?urlappend=%3Fid%3DCCBAU+15615 or 10.1601/strainfinder?urlappend=%3Fid%3DUSDA+4 were below the cutoff values (ANI ≥ 96.5%; DDH ≥ 70%) for strains belonging to the same species, suggesting that ERR11^T is a new species. Therefore, based on the phylogenetic analysis, ANI and DDH values, we formally propose the creation of 10.1601/nm.30737 sp. nov. with strain ERR11^T (10.1601/strainfinder?urlappend=%3Fid%3DHAMBI+3532 ^T=10.1601/strainfinder?urlappend=%3Fid%3DLMG+30162 ^T) as the type strain.