Roseovarius lacus sp. nov., isolated from Yuncheng Saline Lake, China.

Strain GSS12(T), a Gram-negative, aerobic, non-flagellated, ovoid- to rod-shaped (0.5-0.7 × 0.9-3.0 µm) bacterium, was isolated from Yuncheng Saline Lake, China. Growth occurred with 0.5-16.0 % (w/v) NaCl (optimum 4.5 %), at pH 5.0-10.0 (optimum pH 6.0-6.5) and at 10-50 °C (optimum 37 °C). The major fatty acids (>5.0 %) found in GSS12(T) were summed feature 8 (72.2 %), C16:0 (9.0 %) and C18:1 ω7c 11-methyl (6.4 %). The DNA G+C content was 62.7 mol%. Analysis of the 16S rRNA gene sequences showed that strain GSS12(T) forms a stable clade with species of the genus Roseovarius, being related to R. pacificus 81-2(T) and R. litoreus GSW-M15(T) with 97.9 and 96.7 % of sequence similarity, respectively. The DNA-DNA relatedness values between strain GSS12(T) and R. pacificus 81-2(T) and R. halotolerans HJ50(T) were low (36 and 29 %, respectively). The phenotypic, physiological, biochemical and genetic characteristics support the assignment of strain GSS12(T) to the genus Roseovarius and represent a novel species. The name Roseovarius lacus sp. nov. is proposed, with strain GSS12(T) (=KCTC 52185(T) =MCCC 1K02302(T)) as the type strain.