Sphingomonas parvus sp. nov. isolated from a ginseng-cultivated soil

Strain GP20-2(T) was isolated from a soil cultivated with ginseng in Korea. The 16S rRNA gene sequence of this strain showed the highest sequence similarity with Sphingomonas daechungensis CH15-11(T) (96.7%) and Sphingomonas sediminicola Dae 20(T) (96.2%) among the type strains. The strain GP20-2(T) was a strictly aerobic, Gram-negative, non-motile, rod-shaped bacterium that formed very tiny colonies, less than 0.3 mm in diameter after 10 days on R2A agar. The strain grew at 10-35-C (optimum, 35-C), at a pH of 5.0-8.0 (optimum, pH 6.0), and in the absence of NaCl. The DNA G+C content of strain GP20-2(T) was 67.2 mol%. It contained ubiquinone Q-10 as the major isoprenoid quinone, and summed feature 8 (C18:1ω6c and/or C18:1ω7c, 49.8%) and C16:0 (17.0%) as the major fatty acids. On the basis of evidence from our polyphasic taxonomic study, we concluded that strain GP20-2(T) should be classified as a novel species of the genus Sphingomonas, for which the name Sphingomonas parvus sp. nov. is proposed. The type strain is GP20-2(T) (=KACC 12865(T) =DSM 100456(T)).