Two Gram-staining-negative, aerobic, non-spore-forming rod-shaped, non-motile bacteria, designated strains R156-2 T and T58-2 were isolated from the roots of Cymbidium goeringii. The colonies were yellow-pigmented. On the basis of 16S rRNA gene sequence similarity, strains R156-2 T and T58-2 were shown to be members of the genus Chitinophaga. Strains R156-2 T and T58-2 showed the greatest level of sequence similarity with Chitinophaga niabensis (96.0-96.3 %). The major menaquinone was MK-7. The main cellular fatty acids were iso-C 15 : 0 , C 16 : 1 v5c and iso-C 17 : 0 3-OH. Phenotypic and genotypic analyses indicated that strains R156-2 T and T58-2 could not be assigned to any recognized species. Therefore, strains R156-2 T and T58-2 represent a novel species of the genus Chitinophaga, for which the name Chitinophaga cymbidii sp. nov. is proposed. The type strain is R156-2 T (5ACCC. The DNA G+C content of this strain is 51.9 mol%.The genus Chitinophaga, the type genus of the family Chitinophagaceae (Kämpfer et al. 2011), was first described by Sangkhobol & Skerman (1981). At the time of writing, the genus includes 13 species with validly published names. These are Chitinophaga pinensis (Sangkhobol & Skerman, 1981) The diversity of endophytic bacteria was large in the roots of Cymbidium goeringii. Endophytic isolates from the roots of Cymbidium goeringii were grouped into six phyla, including Alphaproteobacteria (50.9 %), Gammaproteobacteria (34.6 %), Betaproteobacteria (6.7 %), Firmicutes (5.2 %), Actinobacteria (1.9 %) and Bacteroidetes (0.7 %), and the dominant genera were Rhizobium (48.3 %) and Dyella (25.8 %) (our unpublished results). A total of 57 indole-3-acetic acidproducing strains and 47 siderophore-producing strains were isolated from the root interior of Cymbidium goeringii (Liu et al., 2010;Sun et al., 2011). In this study, we describe novel strains of a member of the genus Chitinophaga, which were isolated from the root interior of Cymbidium goeringii.Cymbidium goeringii samples, which have grown for 5 years in a greenhouse at the Chinese Academy of Forestry (Beijing, China), were obtained in October 2008. The roots of Cymbidium goeringii were separated from the soil, washed with tap water and surface-sterilized with 70 % ethanol for 3 min, with 3.0 % sodium hypochlorite solution for 2 min and rinsed with 70 % ethanol for 30 s followed by rinsing with sterile distilled water. To confirm that the sterilization process was successful, the aliquots of the sterile distilled water used in the final rinse were set on trypticase soy agar (TSA) medium plates. Samples (1 g) of surfacesterilized roots were ground with a sterile mortar and diluted with sterile 0.85 % sodium chloride using the standard dilution plating technique and then incubated 28 uC for 4 days. Strains R156-2 T and T58-2 were isolated from the plates of R2A agar (Difco) and trypticase soy agar (Difco), respectively. The two strains were purified using the streak plate method and then stored at 280 u C as glycerol suspension (20 %, v/v) a...
