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 degrees C, at pH 7.0-8.0 and in the absence of NaCl. Strain THG-A18(T) displayed beta-glucosidase activity, which enabled it to convert ginsenoside Rb-1 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-16:1 omega 7c and/or C-16:1 omega 6c) and summed feature 9 (comprising iso-C-17:1 omega 9c 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.