Rhizorhabdus dicambivorans sp nov., a dicamba-degrading bacterium isolated from compost

Strain Ndbn-20(T), a Gram-staining-negative, non-spore-forming bacterium, was isolated from compost of plant litter. The strain was able to degrade dicamba. Phylogenetic analysis based on 16S rRNA gene sequences indicated that Ndbn-20(T) represented a member of the family Sphingomonadaceae of the Alphaproteobacteria and showed high sequence similarities to Rhizorhabdusargentea SP1(T) (98.8 %), Sphingomonaswittichii RW1(T) (97.9 %), Sphingomonasstarnbergensis 382(T) (97.7 %) and Sphingomonashistidinilytica UM2(T) (97.7 %). However, the strain showed low DNA sequence relatedness with R. argentea SP1(T) (45.6 +/- 1.9 %), S. wittichii RW1(T) (33.5 +/- 2.3 %), S. histidinilytica UM2(T) (39.4 +/- 3.6 %) and S. starnbergensis 382(T) (42.1 +/- 4.1 %). Ndbn-20(T) possessed Q-10 as the predominant ubiquinone, spermidine as the major polyamine, and summed feature 8 (comprising C-18 : 1 omega 7c/C-18 : 1 omega 6c), summed feature 3 (comprising C-16 : 1 omega 7c/C-16 : 1 omega 6c), C-17 : 1 omega 6c, C-16 : 0 and C(14 : 0)2-OH as the major fatty acids (>5% of the total). The profile of polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, glycolipid, sphingoglycolipid, phosphatidyldimethylethanolamine and phosphatidylglycerol. The DNA G+C content was 65.4 mol%. Based on a polyphasic taxonomic analysis, strain Ndbn-20(T) is proposed to represent a novel species of the genus Rhizorhabdus, with the proposed name of Rhizorhabdus dicambivorans sp. nov. The type strain is Ndbn-20(T) (= CCTCC AB 2016143=KACC 18661).