Leucobacter chromiisoli sp. nov., isolated from chromium-containing chemical plant soil

A Gram-stain-positive, rod-shaped, aerobic, non-motile, non-sporulating bacterial strain, designated CSA1 T , was isolated from chromium-containing soil sampled at a chemical plant. Growth of strain CSA1 T occurred at pH 6–10 (optimum, pH 7), 15–45 °C (optimum, 30 °C) and in the presence of 0.5–6.5 % (w/v) NaCl (optimum, 2 %). The 16S rRNA gene sequence of strain CSA1 T revealed the highest similarity to Leucobacter ruminantium A2 T (97.5 %), Leucobacter tardus K 70/01 T (97.3 %), Leucobacter humi Re6 T (96.6 %), Leucobacter kyeonggiensis F3-P9 T (96.2 %), Leucobacter zeae CC-MF41 T (96.1 %) and Leucobacter weissii S27 T (96.0 %). The draft genome of CSA1 T was approximately 3 350 931 bp in size with a G+C content of 70.6 mol%. The average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values among strain CSA1 T and the selected Leucobacter species were 74.0–79.2 % (ANIb), 84.3–87.1 % (ANIm) and 21.5–25.4 % (dDDH), which are below the recommended cutoff values for species delineation. The major fatty acids were anteiso-C 15 : 0 , iso-C 16 : 0 and anteiso-C 17 : 0 . The polar lipids were diphosphatidylglycerol, phosphatidylglycerol and an unknown glycolipid. The predominant menaquinones were MK-11, MK-8 and MK-6. The cell-wall amino acids were 2,4-diaminobutyric acid, alanine, glycine, glutamic acid and threonine. From the phenotypic, chemotaxonomic and molecular features, strain CSA1 T was considered to represent a novel species of the genus Leucobacter , for which the name Leucobacter chromiisoli sp. nov. is proposed. The type strain is CSA1 T (=JCM 34359 T =CGMCC 1.18746 T ).