Genome-based taxonomy and functional prediction of Sphingomonas fuzhouensis sp. nov. and Massilia phyllosphaerae sp. nov. isolated from Pennisetum sp. with plant growth-promoting potential

Two facultatively aerobic strains, designated SGZ-02^T and SGZ-792^T, were isolated from plant Pennisetum sp., exhibiting the highest 16S rRNA gene sequence similarities with the type strains of Sphingomonas zeae LMG 28739^T (98.6%) and Massilia forsythiae NBRC 114511^T (98.4%), respectively. SGZ-02^T grew between 5 and 45 °C, pH 5.0–11.0 and tolerated NaCl concentrations of 0–4% (w/v), whereas SGZ-792^T thrived at 5–40 °C, pH 5.0–11.0 and NaCl tolerance to 0–3.5% (w/v). The major quinone of SGZ-02^T was ubiquinone-10, with the dominant fatty acids being C_16:0 (13.5%), Summed Feature 3 (6.3%), C_14:02-OH (5.3%) and Summed Feature 8 (66.3%). SGZ-792^T predominantly contained ubiquinone-8, with major fatty acids being C_16:0 (20.3%), Summed Feature 3 (5.0%) and Summed Feature 8 (54.7%). Average nucleotide identity and digital DNA–DNA hybridization values between two strains and their closest references strains were below the bacterial species threshold. Based on genotypic and phenotypic characteristics, strains SGZ-02^T and SGZ-792^T are proposed as novel species within the genera Sphingomonas and Massilia, respectively. The suggested names for the new species are Sphingomonas fuzhouensis sp. nov. (SGZ-02^T = GDMCC 1.4033^T = JCM 36769^T) and Massilia phyllosphaerae sp. nov. (SGZ-792^T = GDMCC 1.4211^T = JCM 36643^T), respectively.