Xanthobacter dioxanivorans sp. nov., a 1,4-dioxane-degrading bacterium

A Gram-stain-negative bacterium, designated as YN2(T), that is capable of degrading 1,4-dioxane, was isolated from active sludge collected from a wastewater treatment plant in Harbin, PR China. Cells of strain YN2(T) were aerobic, motile, pleomorphic rods, mostly twisted, and contained the water-insoluble yellow zeaxanthin dirhamnoside. Strain YN2(T) grew at 10-40 degrees C (optimum, 30 degrees C), pH 5.0-8.0 (pH 7.0) and with 0-1% (w/v) NaCl (0.1%). It also could grow chemolithoautotrophically and fix N-2 when no ammonium or nitrate was supplied. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain YN2(T) belongs to the genus Xanthobacter and shares the highest pairwise identity with Xanthobacter autotrophicus 7c(T) (98.6%) and Xanthobacter flavus 301(T) (98.4%). The major respiratory quinone was ubiquinone-10. Chemotaxonomic analysis revealed that the strain possesses C-16:0, C-19:0 cyclo omega 8c and C-18:1 omega 7c as the major fatty acids. The DNA G+C content was 67.95mol%. Based on genome sequences, the DNA-DNA hybridization estimate values between strain YN2(T) and X. autotrophicus 7c(T), X. flavus 301(T) and X. tagetidis TagT2C(T) (the only three species of Xanthobacter with currently available genomes) were 31.70, 31.30 and 28.50%; average nucleotide identity values were 85.23, 84.84 and 83.59%; average amino acid identity values were 81.24, 80.23 and 73.57%. Based on its phylogenetic, phenotypic, and physiological characteristics, strain YN2(T) is considered to represent a novel species of the genus Xanthobacter, for which the name Xanthobacter dioxanivorans sp. nov. is proposed. The type strain is YN2(T) (=CGMCC 1.19031(T)=JCM 34666(T)).

Automated summary

A novel species of the genus Xanthobacter, named Xanthobacter dioxanivorans sp. nov., was isolated and characterized in this study. This bacterium is capable of degrading 1,4-dioxane and exhibits a wide range of growth conditions.