Pontibacter qinzhouensis sp. nov., isolated from rhizosphere soil of a mangrove plant Rhizophora stylosa

A novel bacterium of the genus Pontibacter, designated GY10130(T), was isolated from rhizosphere soil of a mangrove plant Rhizophora stylosa collected from Guangxi province, China. Strain GY10130(T) was Gram-stain negative, positive for oxidase activities, aerobic, short rod-shaped cells without flagella. Growth was observed at 10-40 degrees C (optimum, 28 degrees C), pH 6.0-9.0 (optimum, 7.0) and NaCl concentrations of 0-4% (optimum, 1%). Strain GY10130(T) is closely related to members of the genus Pontibacter, namely P. beigongshangensis CGMCC 1.17104(T) (97.8%) and P. amylolyticus CGMCC 1.12749(T) (95.0%), P. humi SWU8(T) (94.7%), and less than 94.0% with other currently described type strains of Pontibacter. The strain GY10130(T) showed an ANI value of 80.6% and dDDH value of 23.2% with P. beigongshangensis CGMCC 1.17104(T), followed by P. amylolyticus CGMCC 1.12749(T) with ANI and dDDH values of 72.9 and 13.8%, respectively. Strain GY10130(T) contains carotenoid-like pigments, but flexirubin-type pigments were absent. The cellular fatty acids (> 10%) consist of summed feature 4 (17:1 iso I/anteiso B) and iso-C-15:0. The predominant menaquinone is MK-7. The polar lipids comprise phosphatidylethanolamine, two unidentified glycolipids, two unidentified aminolipids and six unidentified phospholipids. The genome length of strain GY10130(T) was 6.2 Mbp with a DNA G + C content of 47.1 mol% and 4727 protein-coding genes. The result of polyphasic taxonomic study show strain GY10130(T) represents one novel species of Pontibacter, Pontibacter qinzhouensis sp. nov., with the type strain GY10130(T) (=NBRC 113901(T) = CGMCC 1.16772(T)).