A novel aerobic, Gram-staining-negative bacterium, designated strain LAM-WHM-ZC T , was isolated from coastal sediment samples from the Bohai Sea, near Yantai, China. Cells of LAM-WHM-ZC T were non-motile, short-rod-or coccoid-shaped. The temperature and pH ranges for growth were 4-40 8C (optimum: 20-33 8C) and pH 5-9 (optimum: pH 7.5). The strain did not require NaCl for growth but tolerated up to 10 % NaCl (w/v). The major fatty acids of strain LAM-WHM-ZC T were summed feature 3, C 12 : 0 , C 16 : 0 , summed feature 2 and summed feature 8. The predominant respiratory quinone was ubiquinone Q-8. The main polar lipids were diphosphatidyglycerol, phosphatigylethanolamine, phosphatidyglycerol, one phospholipid and four unidentified glycolipids. The DNA G+C content was 59.3 mol% as determined by the melting temperature (T m ) method. Analysis of the 16S rRNA gene sequence indicated that the isolate represented a member of the genus Oceanisphaera and was closely related to Oceanisphaera arctica KCTC 23013 T , Oceanisphaera litoralis DSM 15406 T , Oceanisphaera sediminis KACC 15117 T and Oceanisphaera donghaensis KCTC 12522 T with 97.7 %, 97.1 %, 96.6 % and 96.6 % sequence similarity, respectively. The DNA-DNA hybridization values between strain LAM-WHM-ZC T and the four reference strains were 47.4¡2.8 %, 33.5¡2.2 %, 28.4¡1.8 % and 13.7¡0.8 %, respectively. Based on its phenotypic and genotypic properties, strain LAM-WHM-ZC T is suggested to represent a novel species of the genus Oceanisphaera, for which the name Oceanisphaera psychrotolerans sp. nov. is proposed. The type strain is LAM-WHM-ZC T (5ACCC 06516 T 5JCM 30466 T ).