Mucilaginibacter ginsenosidivorax sp. nov., with ginsenoside converting activity isolated from sediment.

A Gram-reaction-negative, strictly aerobic, non-motile, non-spore-forming, and rod-shaped bacterial strain designated KHI28(T) was isolated from sediment in Gapcheon (river) and its taxonomic position was investigated using a polyphasic approach. Strain KHI28(T) grew at 10-42°C and at pH 5.5-8.5 on R2A and nutrient agar without additional NaCl as a supplement. Strain KHI28(T) possessed ß-glucosidase activity, which was responsible for its ability to transform ginsenosides Rb1 and Re (ones of the dominant active components of ginseng) to C-K and Rg2, respectively. On the basis of 16S rRNA gene sequence similarity, strain KHI28(T) was shown to belong to the family Sphingobacteriaceae and to be related to Mucilaginibacter dorajii DR-f4(T) (97.9% sequence similarity), M. polysacchareus DRP28(T) (97.3%), and M. lappiensis ANJLI2(T) (97.2%). The G+C content of the genomic DNA was 45.8%. The predominant respiratory quinone was MK-7 and the major fatty acids were summed feature 3 (comprising C16:1 ω6c and/or C16:1 ω7c), iso-C15:0 and C16:0. DNA and chemotaxonomic data supported the affiliation of strain KHI28(T) to the genus Mucilaginibacter. Strain KHI28(T) could be differentiated genotypically and phenotypically from the recognized species of the genus Mucilaginibacter. The isolate therefore represents a novel species, for which the name Mucilaginibacter ginsenosidivorax sp. nov. is proposed, with the type strain KHI28(T) (=KACC 14955(T) =LMG 25804(T)).

Mucilaginibacter composti sp. nov., with ginsenoside converting activity, isolated from compost.

The Gram-negative, strictly aerobic, non-motile, non-spore-forming, rod shaped bacterial strain designated TR6-03(T) was isolated from compost, and its taxonomic position was investigated by using a polyphasic approach. Strain TR6-03(T) grew at 4-42°C and at pH 6.0-8.0 on R2A and nutrient agar without NaCl supplement. Strain TR6-03(T) had ß-glucosidase activity, which was responsible for its ability to transform ginsenoside Re (one of the dominant active components of ginseng) to Rg(2). On the basis of 16S rRNA gene sequence similarity, strain TR6-03(T) was shown to belong to the family Sphingobacteriaceae and to be related to Mucilaginibacter lappiensis ANJLI2(T) (96.3% sequence similarity), M. dorajii FR-f4(T) (96.1%), and M. rigui WPCB133(T) (94.1%). The G+C content of the genomic DNA was 45.6%. The predominant respiratory quinone was MK-7 and the major fatty acids were summed feature 3 (comprising C(16:1) ω7c and/or iso-C(15:0) 20H), iso-C(16:0) and iso-C(17:0) 3OH. DNA and chemotaxonomic data supported the affiliation of strain TR6-03(T) to the genus Mucilaginibacter. Strain TR6-03(T) could be differentiated genotypically and phenotypically from the recognized species of the genus Mucilaginibacter. The isolate therefore represents a novel species, for which the name Mucilaginibacter composti sp. nov. is proposed, with the type strain TR6-03(T) (=KACC 14956(T) = KCTC 12642(T) =LMG 23497(T)).

Sphingomonas ginsenosidimutans sp. nov., with ginsenoside converting activity.

The Gram-reaction-negative, strictly aerobic, non-motile, non-spore-forming, and rod-shaped bacterial strain designated Gsoil 1429(T) was isolated from the soil of ginseng cultivating field of Pocheon province in South Korea. This bacterium was characterized in order to determine its taxonomic position by using the polyphasic approach. Strain Gsoil 1429(T) grew well at 25-37°C and at pH 7.0 on R2A and nutrient agar without NaCl supplement. Strain Gsoil 1429(T) had -glucosidase activity, which was responsible for its ability to transform ginsenoside Rb1 (one of the dominant active components of ginseng) to F(2) via gypenoside XVII. On the basis of 16S rRNA gene sequence similarity, strain Gsoil 1429(T) was shown to belong to the family Sphingomonadaceae and to be related to Sphingomonas yunnanensis YIM 003(T) (98.2% sequence similarity), S. phyllosphaerae FA2(T) (97.5%), S. koreensis JSS26(T) (97.3%), and S. asaccharolytica IFO 15499(T) (97.1%). The G+C content of the genomic DNA was 65.6%. The major respiratory quinone was Q-10 and the major fatty acids were summed feature 8 (comprising C(18:1) 7c/ωt/12t), C(16:0) and C(14:0)2OH. DNA and chemotaxonomic data supported the affiliation of strain Gsoil 1429T to the genus Sphingomonas. The DNA-DNA relatedness values between strain Gsoil 1429(T) and its closest phylogenetically neighbours were below 28%. Strain Gsoil 1429(T) could be differentiated genotypically and phenotypically from the recognized species of the genus Sphingomonas. The isolate therefore represents a novel species, for which the name Sphingomonas ginsenosidimutans sp. nov. is proposed, with the type strain Gsoil 1429(T) (=KACC 14949(T) =JCM 17074(T) =LMG 25799(T)).