Nocardioides pelophilus sp. nov., isolated from freshwater mud.

A Gram-stain-positive, aerobic, motile, rod- or cocci-shaped bacterium with flagella bacterium (THG-T63) was isolated from freshwater mud. Growth occurred at 10-40 °C (optimum, 28-35 °C), at pH 6-8 (optimum, 7) and at 0-6 % NaCl (optimum, 2 %). Based on 16S rRNA sequence analysis, the nearest phylogenetic neighbours of strain THG-T63 were identified as Nocardioides panacisoli KCTC 19470 (97.5 %), Nocardioides caeni KCTC 19600 (96.4 %), Nocardioides humi KCTC 19265 (96.3 %), Nocardioides kongjuensis KCTC 19054 (96.1 %) and Nocardioides nitrophenolicus KCTC 457BP (96.1 %). 16S rRNA sequence similarities among strain THG-T63 and other species were lower than 96.0 %. The polar lipids were phosphatidylglycerol, phosphatidylinositol and one unidentified phospholipid. The quinone system was composed of MK-8 (H4). The major fatty acids were C16 : 0, C17 : 1ω6c, C17 : 1ω8c, C18 : 0 10-methyl, C18 : 1ω9c and iso-C16 : 0. The cell-wall peptidoglycan contained ll-2,6-diaminopimelic acid. The DNA G+C content of strain THG-T63 was 74.6 mol%. Strain THG-T63 exhibited levels of DNA-DNA relatedness of 20-44 % to the type strains of phylogenetically related Nocardioides species and could be differentiated from these species based on differences in phenotypic characteristics. On the basis of the data presented here, strain THG-T63 represents a novel species of the genus Nocardioides, for which the name Nocardioides pelophilus sp. nov. is proposed. The type strain is THG-T63(=KACC 19192=CGMCC 4.7388).