Paenibacillus roseus sp. nov., a ginsenoside-transforming bacterium isolated from forest soil

Abstract

A novel, pink-pigmented, Gram-stain-positive, aerobic, motile, rod-shaped and ginsenoside-converting bacterium, designated strain MAHUQ-46(T), was isolated from soil of a forest. Strain MAHUQ-46(T) grew in the pH range 6.0-9.0 (optimum, 7.5), at temperatures between 10 and 37 degrees C (optimum, 30 degrees C) and at 0-3% (w/v) NaCl (optimum, 0.5%). 16S rRNA gene sequence analysis showed that strain MAHUQ-46(T) was closely related to Paenibacillus pinihumi S23(T) (97.3% similarity), followed by Paenibacillus elymi KUDC6143(T) (96.7%). The draft genome of strain MAHUQ-46(T) had a total length of 5,367,904 base pairs. A total of 4,857 genes were identified, in which 4,629 were protein-coding genes and 137 were RNA genes. The genome annotation of MAHUQ-46(T) showed 172 carbohydrate genes, some of them may be responsible for the biosynthesis of ginsenoside Rd from major ginsenoside Rb1. The DNA G + C content was 48.4 mol% and the major quinone was MK-7. Main fatty acids of strain MAHUQ-46(T) were C-15: 0 anteiso, C-16: 0 and C-17: 0 anteiso. The polar lipids comprised phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidyl-N-methylethanolamine, two unidentified aminophospholipids and five unidentified phospholipids. Diagnostic diamino acid of peptidoglycan was meso-diaminopimelic acid. The novel strain MAHUQ-46(T) was able to rapidly synthesize ginsenoside Rd from major ginsenoside Rb1. The synthesized ginsenoside was confirmed by TLC and HPLC analysis. According to the phenotypic, genetic and chemotaxonomic evidence, strain MAHUQ-46(T) was clearly distinguishable from validly published species of genus Paenibacillus and should, therefore, be categorized as a novel species for which the name Paenibacillus roseus sp. nov. is proposed. The type strain is MAHUQ-46(T) (= KACC 21242(T) = CGMCC 1.17353(T)).