Novosphingobium arabidopsis sp. nov., a DDT-resistant bacterium isolated from the rhizosphere of Arabidopsis thaliana

Abstract

An aerobic, Gram-stain-negative, rod-shaped, DDT-resistant bacterium, designated strain CC-ALB-2T, was isolated from the Arabidopsis thaliana rhizosphere. Strain CC-ALB-2T was able to grow at 25–37 °C, at pH 5.0–8.0, with 1.0 % (w/v) NaCl and tolerate up to 200 mg l−1 DDT. 16S rRNA gene sequence analysis of strain CC-ALB-2T showed highest sequence similarity to Novosphingobium stygium KCTC 2891T (97.1 %) and Novosphingobium soli DSM 22821T (96.8 %), and lower levels of similarity (<97.0 %) to other species of the genus Novosphingobium . The major fatty acid profile consisted of C14 : 0 2-OH (13.1 %), C16 : 0 (10.0 %), C15 : 0 iso 3-OH (5.8 %), C16 : 1ω7c/C16 : 1ω6c (summed feature 3, 24.7 %) and C18 : 1ω7c/C18 : 1ω6c (summed feature 8, 42.4 %). The polar lipid profile constitutes sphingoglycolipid, glycolipid, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidyldimethylethanolamine, phosphatidylglycerol and phosphatidylcholine. The polyamine pattern showed a predominance of spermidine as the major polyamine. The predominant quinone system was ubiquinone (Q-10). The DNA G+C content was 68.9±0.1 mol%. Based on the phylogenetic, phenotypic and chemotaxonomic features, strain CC-ALB-2T is proposed to represent a novel species of the genus Novosphingobium for which the name Novosphingobium arabidopsis sp. nov. is proposed. The type strain is CC-ALB-2T ( = BCRC 80571T = JCM 18896T).