Chryseobacterium taihuense sp. nov., isolated from a eutrophic lake, and emended descriptions of the genus Chryseobacterium, Chryseobacterium taiwanense, Chryseobacterium jejuense and Chryseobacterium indoltheticum.

Bacterial strain THMBM1(T) was isolated from decomposing algal scum that was collected during an algal bloom in Lake Taihu, Wuxi City, Jiangsu Province, China. Cells of strain THMBM1(T) were Gram-negative, facultatively anaerobic, non-motile rods. Colonies on tryptic soy agar were translucent and shiny with entire edges; yellow flexirubin-type pigments were produced. Growth was observed at 15-45 °C (optimum 30-37 °C), at pH 5.0-9.0 (optimum pH 8.0) and in the presence of 0-4.0 % (w/v) NaCl (optimum 0-1.0 %). Strain THMBM1(T) contained MK-6 as the sole respiratory quinone and sym-homospermidine as the predominant polyamine. The predominant cellular fatty acids were iso-C15 : 0 (53.2 %), iso-C17 : 0 3-OH (15.6 %) and iso-C17 : 1ω9c (11.9 %). The polar lipid profile consisted of phosphatidylethanolamine and five unidentified lipids. The DNA G+C content was 36.8 mol% (Tm). Strain THMBM1(T) was closely related to members of the genus Chryseobacterium, with 16S rRNA gene sequence similarities ranging from 92.9 to 97.2 %, the highest sequence similarities being with Chryseobacterium taiwanense BCRC 17412(T) (97.2 %) and C. gambrini 5-1St1a(T) (97.1 %). DNA-DNA relatedness between strain THMBM1(T) and C. taiwanense JCM 21767(T) and C. gambrini DSM 18014(T) was 34.1  and 23.0 %, respectively. Based on these results, it is concluded that strain THMBM1(T) represents a novel species, for which the name Chryseobacterium taihuense sp. nov. is proposed. The type strain is THMBM1(T) ( = CGMCC 1.10941(T)  = NBRC 108747(T)). Emended descriptions of the genus Chryseobacterium and C. taiwanense, C. jejuense and C. indoltheticum are also proposed.