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

Strain Ndbn-20T, 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-20Trepresented a member of the family Sphingomonadaceae of the Alphaproteobacteria and showed high sequence similarities to Rhizorhabdusargentea SP1T (98.8 %), Sphingomonaswittichii RW1T (97.9 %), Sphingomonasstarnbergensis 382T (97.7 %) and Sphingomonashistidinilytica UM2T (97.7 %). However, the strain showed low DNA sequence relatedness with R. argentea SP1T (45.6±1.9 %), S. wittichii RW1T (33.5±2.3 %), S.histidinilytica UM2T (39.4±3.6 %) and S. starnbergensis382T (42.1±4.1 %). Ndbn-20T possessed Q-10 as the predominant ubiquinone, spermidine as the major polyamine, and summed feature 8 (comprising C18 : 1ω7c/C18 : 1ω6c), summed feature 3 (comprising C16 : 1ω7c/C16 : 1ω6c), C17 : 1ω6c, C16 : 0 and C14 : 02-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-20T 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-20T (=CCTCC AB 2016143=KACC 18661).