Stappia sediminis sp. nov., isolated from rhizosphere soil of coastal herb Zoysia matrella within the Beibu Gulf.

A bacterial isolate (BGMRC 2046) was isolated from the rhizosphere soil of Zoysia matrella collected from the Beibu Gulf of China. The results of a polyphasic taxonomic study revealed that this strain belongs to a member of the genus Stappia with the characteristics of Gram-stain-negative, catalase- and oxidase-positive, motile, short rod-shaped. The strain grew at 20-37 °C (optimal, 28 °C), pH 6.0-9.0 (optimal, pH 7.0), and 1-7% (w/v) optimal, NaCl (1-3%). A phylogenetic evaluation based on 16S rRNA gene sequence analysis revealed that this strain fall into the family Stappiaceae, being most closely related to Stappia indica CGMCC 1A01226 (95.8% sequence similarity), Stappia stellulata DSM 5886 (95.1%), and Stappia taiwanensis DSM 23284 (94.4%). The major cellular fatty acid, respiratory quinone and polar lipids were all detected from new species (BGMRC 2046T), that shows the chemical characteristics of BGMRC 2046T. The major polar lipids were two unidentified ninhydrin positive phospholipids, four unidentified phospholipids, and one unidentified lipid. Genome sequencing revealed a genome size of 4.78 Mbp and a G + C content of 60.8%. Pairwise comparison of the genomes of the new strain BGMRC 2046 and the three most closely related strains resulted in gANI values was lower than 75% and a digital DNA-DNA hybridization values was lower than 24%. The strain possessed genes encoding choline uptake and conversion to betaine gene clusters. The results of the polyphasic taxonomic study showed that strain BGMRC 2046 represents a new species of the genus Stappia. The name Stappia sediminis sp. nov. is proposed for the species with the type strain BGMRC 2046 (= KCTC52115 = CGMCC1.17425).