Chryseobacterium gwangjuense sp. nov., isolated from soil

A Gram-stain-negative, strictly aerobic, non-motile, rod-shaped bacterial strain, THG-A18^T, was isolated from soil of Gwangju province in South Korea. Strain THG-A18^T grew optimally at 25–30 °C, at pH 7.0–8.0 and in the absence of NaCl. Strain THG-A18^T displayed β-glucosidase activity, which enabled it to convert ginsenoside Rb₁ to Rd. According to 16S rRNA gene sequence analysis, strain THG-A18^T was shown to belong to the genus Chryseobacterium. The closest phylogenetic neighbours were Chryseobacterium ginsenosidimutans THG 15^T (97.9 % 16S rRNA gene sequence similariity), C. defluvii B2^T (97.7 %), C. daeguense K105^T (97.6 %), C. taiwanense BCRC 17412^T (97.5 %), C. indoltheticum LMG 4025^T (97.4 %), C. gregarium P 461/12^T (97.4 %) and C. lathyri RBA2-6^T (97.3 %), but DNA–DNA relatedness values between these strains and strain THG-A18^T were below 41.9 %. The G+C content of the genomic DNA was 36.4 mol%. The major respiratory quinone (MK-6) and fatty acids [iso-C_15 : 0, iso-C_17 : 0 3-OH, summed feature 3 (comprising C_16 : 1ω7c and/or C_16 : 1ω6c) and summed feature 9 (comprising iso-C_17 : 1ω9c and/or 10-methyl C_16 : 0)] supported the affiliation of strain THG-A18^T with the genus Chryseobacterium. The polar lipids of strain THG-A18^T were phosphatidylethanolamine, four unidentified aminolipids and seven unidentified lipids. A number of physiological and biochemical tests allowed phenotypic differentiation of strain THG-A18^T from recognized species of the genus Chryseobacterium. The name Chryseobacterium gwangjuense sp. nov. is proposed, with THG-A18^T ( = KACC 16227^T = LMG 26579^T) as the type strain.