Gracilibacillus oryzae sp. nov., isolated from rice seeds

A Gram-stain-positive, facultatively anaerobic, endospore-forming bacterium, designated strain TD8^T, was isolated from surface-sterilized rice seeds (Oryza sativa L.). Phylogenetic analysis of the 16S rRNA gene indicated that strain TD8^T should be placed within the genus Gracilibacillus (95.2-99.0 % sequence similarity); it exhibited highest similarities to Gracilibacillus ureilyticus CGMCC 1.7727^T (99.0 %), 'Gracilibacillus xinjiangensis' CGMCC 1.12449^T (98.9 %) and Gracilibacillus dipsosauri CGMCC 1.3642^T (97.5 %). Chemotaxonomic analysis showed that menaquinone-7 (MK-7) was the major isoprenoid quinone. Diphosphatidylglycerol, phosphatidylglycerol and one unidentified phospholipid were the major cellular polar lipids, and the major fatty acids were anteiso-C_15 : 0, anteiso-C_17 : 0, iso-C_15 : 0, C_16 : 0 and iso-C_16 : 0, which supported the allocation of the strain to the genus Gracilibacillus. The digital DNA-DNA hybridization value between strain TD8^T and Gracilibacillus ureilyticus CGMCC 1.7727^T was lower than 70 % (22.60 %), and the average nucleotide identity score was 79.54±5.09 %, suggesting that strain TD8^T represented a novel species in the genus Gracilibacillus. The genomic DNA G+C content was 37.5 %. Based on physiological and biochemical characteristics and genotypic data, strain TD8^T represents a novel species of the genus Gracilibacillus, for which the name Gracilibacillus oryzae sp. nov. is proposed. The type strain is TD8^T (=ACCC 61556^T=CICC 24889^T=JCM 33537^T).