Description of Paenibacillus jiagnxiensis sp. nov., a mesotrione-degrading bacterium isolated from farmland and cloning of a novel mesotrione nitroreductase gene.

A Gram positive, aerobic, cream-white, motile, and rod-shaped bacterium, designated as P8, was isolated from the soil collected from a farmland in JiangXi Province, China. Strain P8 efficiently transformed herbicide mesotrione to 2-amino-4-methylsulfonylbenzoic acid (AMBA). Strain P8 showed the highest 16S rRNA gene sequence similarity with Paenibacillus terreus D33 (97.4%). Phylogenetic trees based on 16S rRNA gene and genome sequences indicated that strain P8 formed a distinct clade within the genus Paenibacillus. The major cellular fatty acids were anteiso-C, C, anteiso-C and iso-C, the predominant menaquinone was menaquinone-7 (MK-7), the polar lipids profile consisted of phosphatidyl ethanolamine (PE), phosphatidyl monomethyl ethanolamine (PME), phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), one unidentified aminolipid (AL), one unidentified aminophospholipid (APL), two unidentified glycolipids (GL1-2), two unidentified phospholipids (PL1-2), and two unidentified polar lipids (L1-2). The DNA G + C content was 49.9%. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between P8 and closely related type strains in genus Paenibacillus were 70.4-93.0% and 13.0-48.3%, respectively. Based on the phenotypic, phylogenetic and genomic results, strain P8 represents a novel species of the genus Paenibacillus, for which the name Paenibacillus jiagnxiensis sp. nov. is proposed, with strain P8 (= KCTC 43704 = MCCC 1K09190) as the type strain. Furthermore, a nitroreductase gene (WP355320791), designated as mstnr, that efficiently transformed mesotrione to AMBA was identified in strain P8. Mstnr consists of 219 amino acids, and shares low similarities (less than 32%) with reported mesotrione nitroreductases.