Novosphingobium chloroacetimidivorans sp. nov., a chloroacetamide herbicide–degrading bacterium isolated from activated sludge

Abstract

Strain BUT-14T, a Gram-reaction-negative, non-spore-forming, ellipse-shaped bacterium, was isolated from activated sludge of a chloroacetamide-herbicides-manufacturing wastewater treatment facility. The strain was able to degrade more than 90 % of butachlor, acetochlor and alachlor (100 mg l−1) within 5 days of incubation. The taxonomic position was investigated using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain BUT-14T was a member of the genus Novosphingobium and showed the highest sequence similarities to Novosphingobium soli DSM 22821T (97.9 %), N. naphthalenivorans KACC 15258T (97.4 %), N. pentaromativorans JCM 12182T (97.4 %) and N. barchaimii DSM 25411T (97.1 %) and lower (<97 %) sequence similarities to all other species of the genus Novosphingobium . Chemotaxonomic analysis revealed that strain BUT-14T possessed Q-10 as the predominant ubiquinone, spermidine as the major polyamine and C18 : 1ω7c (46.9 %), C17 : 1ω6c (17.9 %), summed feature 3, C14 : 0 2-OH (4.4 %), C15 : 0 2-OH (3.1 %) and C16 : 0 (5.51 %) as the major fatty acids. The polar lipids included lipid, glycolipid, phosphatidylglycerol, phospholipid, phosphatidylethanolamine, phosphatidylcholine, sphingoglycolipid and phospatidyldimethylethanolamine. Strain BUT-14T showed low DNA–DNA relatedness with N. soli DSM 22821T (41.5±2.9 %), N. naphthalenivorans JCM 12182T (49.2±4.2 %), N. pentaromativorans KACC 12295T (53.2±1.9 %) and N. barchaimii DSM 25411 (51.2±4.5 %). The DNA G+C content was 66±0.3 mol%. The combination of phylogenetic analysis, phenotypic characteristics, chemotaxonomic data and DNA–DNA hybridization supports the suggestion that strain BUT-14T represents a novel species of the genus Novosphingobium , for which the name Novosphingobium chloroacetimidivorans sp. nov. is proposed. The type strain is BUT-14T ( = CCTCC AB 2013086T = KACC 17147T = JCM 19923T).