Brevibacterium metallicus sp. nov., an endophytic bacterium isolated from roots of Prosopis laegivata grown at the edge of a mine tailing in Mexico

A Gram-positive, aerobic, nonmotile strain, NM2E3^T was identified as Brevibacterium based on the 16S rRNA gene sequence analysis and had the highest similarities to Brevibacterium jeotgali SJ5-8^T (97.3 %). This novel bacterium was isolated from root tissue of Prosopislaegivata grown at the edge of a mine tailing in San Luis Potosí, Mexico. Its cells were non-spore-forming rods, showing catalase and oxidase activities and were able to grow in LB medium added with 40 mM Cu²⁺, 72 mM As⁵⁺ and various other toxic elements. Anteiso-C_15:0 (41.6 %), anteiso-C_17:0 (30 %) and iso-C_15:0 (9.5 %) were the major fatty acids. MK-8(H₂) (88.4 %) and MK-7(H₂) (11.6 %) were the major menaquinones. The DNA G + C content of the strain NM2E3^T was 70.8 mol % (Tm). DNA–DNA hybridization showed that the strain NM2E3^T had 39.8, 21.7 and 20.3 % relatedness with B. yomogidense JCM 17779^T, B. jeotgali JCM 18571^T and B. salitolerans TRM 45^T, respectively. Based on the phenotypic and genotypic analyses, the strain NM2E3^T (=CCBAU 101093^T = HAMBI 3627^T = LMG 8673^T) is reported as a novel species of the genus Brevibacterium, for which the name Brevibacterium metallicus sp. nov., is proposed.