Methylobacterium amylolyticum sp. nov. and Methylobacterium ligniniphilum sp. nov., isolated from soil

Two pink-pigmented bacteria, designated strains NEAU-140 T and NEAU-K T , were isolated from field soil collected from Linyi, Shandong Province, PR China. Both isolates were aerobic, Gram-stain-negative, rod-shaped, and facultatively methylotrophic. 16S rRNA gene sequences analysis showed that these two strains belong to the genus Methylobacterium . Strain NEAU-140 T exhibited high 16S rRNA gene sequence similarities to Methylobacterium radiotolerans NBRC 15690 T (97.43 %) and Methylobacterium phyllostachyos NBRC 105206 T (97.36 %). Strain NEAU-K T exhibited high 16S rRNA gene sequence similarities to M. phyllostachyos NBRC 105206 T (99.00 %) and Methylobacterium longum DSM 23933 T (98.72 %). A phylogenetic tree based on 16S rRNA gene sequences showed that strain NEAU-140 T formed a clade with Methylobacterium aerolatum (95.94 %), Methylobacterium persicinum (95.66 %) and Methylobacterium komagatae (96.87 %), and strain NEAU-K T formed a cluster with M. phyllostachyos and M. longum . The predominant fatty acid in both strains was C 18 : 1 ω 7 c . Both strains contained ubiquinone Q-10 as the only respiratory quinone. The polar lipid profiles of both strains contained diphosphatidylglycerol, phosphatidylethanolamine, and phosphatidylcholine. Whole-genome phylogeny showed that strains NEAU-140 T and NEAU-K T formed a phyletic line with M. aerolatum , M. persicinum , Methylobacterium radiotolerans , Methylobacterium fujisawaense , Methylobacterium oryzae , Methylobacterium tardum , M. longum and M. phyllostachyos . The orthologous average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values between strain NEAU-140 T and its closely related strains were lower than 82.62 and 25.90 %, respectively. The ANI and dDDH values between strain NEAU-K T and its closely related strains were lower than 86.29 and 31.7 %, respectively. The genomic DNA G+C contents were 71.63 mol% for strain NEAU-140 T and 69.08 mol% for strain NEAU-K T . On the basis of their phenotypic and phylogenetic distinctiveness and the results of dDDH and ANI hybridization, these two isolates represent two novel species within the genus Methylobacterium , for which the names Methylobacterium amylolyticum sp. nov. (type strain NEAU-140 T =MCCC 1K08801 T =DSM 110568 T ) and Methylobacterium ligniniphilum sp. nov. (type strain NEAU-K T =MCCC 1K08800 T =DSM 110567 T ) are proposed.