Paenibacillus mesotrionivorans sp. nov., a Mesotrione-Degrading Strain Isolated from Soil.

A Gram-stain-positive, facultatively anaerobic, motile with peritrichous flagella, and rod-shaped bacterium, designated as P15, was isolated from an agricultural soil sample collected in Jiangxi Province, PR China. Strain P15 completely degraded 100 mg/L of mesotrione, a herbicide, within 48 h of incubation. Strain P15 grew at 15-42 °C (optimum 30 °C), pH 6.0-9.0 (optimum 7.0), and 0-4.0% (w/v) NaCl (optimum 1.0%). Strain P15 exhibited less than 93.3% 16S rRNA gene sequence similarity with type strains of genus Paenibacillus. In the phylogenetic tree based on 16S rRNA gene sequences, strain P15 was clustered in genus Paenibacillus and formed a subclade with P. cavernae C4-5, P. contaminans CKOBP-6, and P. doosanensis CAU 1005. The major cellular fatty acids (≥ 5% of the total) were anteiso-C, iso-C, C, C, and iso-C. The predominant respiratory quinone was MK-7. The major polar lipids were diphosphatidylglycerol, phosphatidylglycero, phosphatidylethanolamine, one unidentified glycolipid, one unidentified aminophosphoglycolipid, two unidentified aminophospholipids, two unidentified phospholipid, and two unidentified lipids. The diagnostic diamino acid of the peptidoglycan was meso-diaminopimelic acid. The DNA G + C content was 53.9 mol%. Based on the phylogenetic, phenotypic, and chemotaxonomic characteristics, strain P15 represents a novel species within genus Paenibacillus, for which the name Paenibacillus mesotrionivorans sp. nov is proposed, with strain P15 (= MCCC 1K09191 = KCTC 43705) as the type strain.