A Gram-reaction negative, aerobic, non-motile, light yellow colored, and rod-shaped bacterium (designated Gr-4(T)) isolated from granules of a wastewater treatment plant, was characterized by a polyphasic approach to clarify its taxonomic position. Strain Gr-4(T) was observed to grew optimally at 30 oC and at pH 7.0 on R2A medium. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain Gr-4(T) belongs to the genus Luteimonas of the family Xanthomonadaceae and was most closely related to Luteimonas padinae CDR SL 15(T) (99.1%), Luteimonas terricola DSM 22344(T) (98.5%) and Luteimonas arsenica 26-35(T) (97.6). The genome comprises 2,917,404 bp with a G+C content of 70.5 mol%. The ANI value between strain Gr-4(T) and Luteimonas padinae CDR SL 15(T) was 87.3%. The DNA-DNA relatedness value between strain Gr-4(T) and Luteimonas padinae CDR SL 15(T), Luteimonas terricola DSM 22344(T) was 36.4 +/- 1.3% and 14.2 +/- 1.7%, respectively. The predominant quinone was Q-8. The major fatty acids were iso-C-15:0, iso-C-16:0 and summed feature 9 (comprising iso-C-17:1 omega 9c and/or C-16:0 10-methyl) supported the affiliation of strain Gr-4(T) to the genus Luteimonas. Moreover, the physiological, biochemical results, and low level of ANI and DNA-DNA relatedness value allowed the phenotypic and genotypic differentiation of strains Gr-4(T) from other Luteimonas species with validly published names. The novel isolate therefore represents a novel species, for which the name Luteimonas granuli sp. nov. is proposed, with the type strain Gr-4(T) (=KACC 16614(T) = JCM 18203(T)).