Isolation and characterization of two novel species Neorhizobium fuzhouense sp. nov. and Neotabrizicola paludis sp. nov

Two novel aerobic bacterial strains, designated SGZ-38^T and sgz301269^T, were isolated from the root of Pennisetum sp. and paddy soil, respectively. Strain SGZ-38^T grew at 10–40 ℃ (optimum 30 °C) and pH 5.0–12.0 (optimum 6.5) and tolerated up to 1.0% NaCl (w/v), whereas strain sgz301269^T grew at 15–37 °C (optimum 30 °C), pH 5.0–9.5 (optimum 7.0) and 0–2% NaCl (optimum 0%). Phylogenetic trees based on the 16S rRNA gene and genomes placed both strains into distinct lineages, forming separated clades from their closest relatives. Strain SGZ-381^T exhibited the highest 16S rRNA gene similarities to “Neorhizobium deserti” ACCC 61627^T (97.4%), and strain sgz301269^T had the highest 16S rRNA gene sequence similarity to Neotabrizicola shimadae N10^T (97.6%). The respiratory quinone in both strains was ubiquinone-10. The main fatty acids of SGZ-381^T were Summed feature 8, Summed feature 2 and C_16:0, whereas strain sgz301269^T included C_10:0 3OH, C_18:0 3OH and Summed feature 8. The DNA G+C content of SGZ-381^T and sgz301269^T was 62.1% and 65.5%, respectively. The average nucleotide identity and digital DNA–DNA hybridization values between each strain and their respective closest species were 74.6% and 20.1%, 75.3% and 17.4% respectively, below the thresholds for species delineation. Based on the comprehensive chemotaxonomic, phylogenetic, and phenotypic evidence, proposed names of the novel strains are Neorhizobium fuzhouense sp. nov. (type strain SGZ-381^T=GDMCC1.4207^T=JCM 36770^T), Neotabrizicola paludis sp. nov. (type strain sgz301269^T=MCCC 1K09178^T=KCTC 8856^T).