A Gram-stain-positive, facultatively anaerobic, rod-shaped bacterium, designated JX-17(T), was isolated from a soil sample collected in Jiangxi Province, PR China. Growth was observed at 15-48(degrees)C (optimum 37 C-degrees), at pH 5.0-9.0 (optimum pH 7.0) and with 0-6.0% (w/v) NaCl (optimum 1.0%). Strain JX-17(T) could degrade approximately 50% of 50 mg/L mesotrione within 2 days of incubation, but could not use mesotrione as sole carbon source for growth. Strain JX-17(T) showed less than 95.3% 16S rRNA gene sequence similarity with type strains of the genus Paenibacillus. In the phylogenetic tree based on 16S rRNA gene and genome sequences, strain JX-17(T) formed a distinct lineage within the genus Paenibacillus. The ANI values between JX-17(T) and the most closely related type strains P. lentus CMG1240(T) and P. farraposensis UY79(T) were 70.1% and 71.4%, respectively, and the dDDH values between them were 19.0% and 23.3%, respectively. The major cellular fatty acids were anteiso-C-15:0, iso-C-16:0, anteiso-C-17:0 and C-16:0, the predominant respiratory quinone was MK-7, the major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, an unidentified glycolipid, an aminophospholipid and a phosphatidylinositol. The diagnostic diamino acid of the peptidoglycan was meso-diaminopimelic acid, and the DNA G + C content was 50.1 mol%. Based on the phylogenetic, phenotypic and chemotaxonomic characteristics, strain JX-17(T) represents a novel species within the genus Paenibacillus, for which the name Paenibacillus lacisoli sp. nov is proposed, with strain JX-17(T) (= GDMCC 1.3962(T) = KCTC 43568(T)) as the type strain.