Phytobacter palmae sp. nov., a novel endophytic, N2 fixing, plant growth promoting Gammaproteobacterium isolated from oil palm (Elaeis guineensis Jacq.)

A novel strain S29 T with high nitrogen fixing ability was isolated from surface-sterilized leaf tissues of oil palm ( Elaeis guineensis ) growing in Science Park II, Singapore. On the basis of 16S rRNA gene analysis and multilocus sequence typing with the rpoB, gyrB, infB and atpD genes, strain S29 T was a member of the genus Phytobacter , with Phytobacter ursingii ATCC 27989 T and Phytobacter diazotrophicus LS 8 T as its closest relatives. Unique biochemical features that differentiated strain S29 T from its closest relatives were the ability to utilize melibiose, α -cyclodextrin, glycogen, adonital, d -arabitol, m -inositol and xylitol. The major fatty acids were C 14 : 0 , C 16 : 0 , C 17 : 0 , C 16 : 1 ω 5c and summed feature 2 containing C 16 : 1 ω 7c and/or C 16 : 1 ω 6c. The polar fatty acid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified aminophospholipid and aminolipids. The draft genome of strain S29 T comprised 5, 284, 330 bp with a G + C content of 52.6 %. The average nucleotide identity and digital DNA–DNA hybridization values between strain S29 T and the phylogenetically related Enterobacterales species were lower than 95 % and 70 %, respectively. Thus, the polyphasic evidences generated through the phenotypic, chemotaxonomic and genomic methods confirmed that strain S29 T represents a novel species of the genus Phytobacter , for which we propose the name Phytobacter palmae sp. nov. with the type strain of S29 T (=DSM 27342 T =KACC 17598 T ).