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

Abstract

A Gram positive, aerobic, cream-white, motile, and rod-shaped bacterium, designated as P8^T, was isolated from the soil collected from a farmland in JiangXi Province, China. Strain P8^T efficiently transformed herbicide mesotrione to 2-amino-4-methylsulfonylbenzoic acid (AMBA). Strain P8^T showed the highest 16S rRNA gene sequence similarity with Paenibacillus terreus D33^T (97.4%). Phylogenetic trees based on 16S rRNA gene and genome sequences indicated that strain P8^T formed a distinct clade within the genus Paenibacillus. The major cellular fatty acids were anteiso-C_15:0, C_16:0, anteiso-C_17:0 and iso-C_16:0, 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^T 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^T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus jiagnxiensis sp. nov. is proposed, with strain P8^T (= KCTC 43704 ^T = MCCC 1K09190^T) as the type strain. Furthermore, a nitroreductase gene (WP355320791), designated as mstnr, that efficiently transformed mesotrione to AMBA was identified in strain P8^T. Mstnr consists of 219 amino acids, and shares low similarities (less than 32%) with reported mesotrione nitroreductases.