Abstract
Bacterial strain LW4T was isolated from activated sludge of a wastewater-treatment bioreactor. Cells of strain LW4T were Gram-positive cocci, with a diameter of 0.71.0 µm. Colonies produced on LB agar plates were yellow, smooth, circular and 0.51.5 mm in diameter. Strain LW4T was aerobic and grew over the temperature range 2634 °C and pH range 59, with optimal growth at 30.531.5 °C and pH 6.06.2. The cell-wall peptidoglycan of strain LW4T contained amino acid residues of lysine, glutamic acid, alanine, glycine and aspartic acid. The most abundant cellular fatty acids of strain LW4T were anteiso-C15 : 0 (32.15 %) and iso-C15 : 0 (31.65 %). Major respiratory quinones were MK-8(H2) (57.3 %) and MK-7(H2) (32.9 %). The DNA G+C content was 71.4 mol% (Tm). 16S rRNA gene sequence analysis indicated that strain LW4T was phylogenetically related to members of the genus Micrococcus, with similarities ranging from 96.5 to 97.3 %. Levels of DNADNA relatedness of strain LW4T to Micrococcus luteus DSM 20030T, Micrococcus lylae DSM 20315T and Micrococcus antarcticus AS 1.2372T were 55, 48 and 36 %, respectively. Based on these results, it is concluded that strain LW4T represents a novel species of the genus Micrococcus, for which the name Micrococcus flavus sp. nov. is proposed. The type strain is strain LW4T (=CGMCC 1.5361T=JCM 14000T).