Bacillus graminis sp. nov., an endophyte isolated from a coastal dune plant surface-sterilized roots of a halophyte (Elymus mollis Trin.) inhabiting coastal tidal flats of Namhae Island, located on the southern coast of Korea, and was subjected to a polyphasic taxonomic study. Cells were facultatively anaerobic, endospore-forming rods to coccoid rods, motile by a single flagellum. Strain YC6957 T was catalase-positive, oxidase-negative and able to grow in the presence of 0-8 % (w/v) NaCl, with optimum growth at 4-5 % (w/v) NaCl. Growth occurred at 15-45 6C (optimal growth at 30-35 6C) and pH 6.0-8.5 (optimal growth at pH 7.0-8.0). The predominant isoprenoid quinone was menaquinone 7 (MK-7). The major cellular fatty acids were C 16 : 0 (11.3 %), iso-C 15 : 0 (19.2 %) and anteiso-C 15 : 0 (36.4 %). The cell-wall peptidoglycan contained meso-diaminopimelic acid. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Species of the genus Bacillus have been isolated from a wide variety of environments, and their ubiquitous distribution in nature is due to the resistance of their endospores to stressful environmental conditions. Members of the genus Bacillus are also common residents of internal tissues of terrestrial and aquatic plants, where these micro-organisms play an important role in plant protection and growth promotion and facilitate plant growth under biotic and abiotic stress conditions (Ji et al., 2008; Sgroy et al., 2009). Although Bacillus species have been isolated from a wide range of habitats, to the best of our knowledge, only one Bacillus strain belonging to a species with a validly published name, Bacillus endophyticus (Reva et al., 2002), has been isolated from inner tissues of a plant root. In the course of a study of the endophytic bacterial diversity of coastal sand-dune halophytes, several endophytes related to the genus Bacillus were isolated from different halophytes, and a novel strain, YC6957T , belonging to the genus Bacillus was isolated from the roots of a dune grass.
Strain YC6957T was isolated from the roots of a coastal sand-dune plant, Elymus mollis Trin., growing on coastal tidal flats of Namhae Island (34 u 509 15.620 N 127 u 539 32.720 E), located midway along the south coast of Korea. Isolation was carried out as described previously (Chung et al., 2008). Root pieces were washed several times with running tap water and surface sterilized by stepwise washing in 70 % ethanol for 5 min, 1.0 % NaOCl for 10 min and 70 % ethanol for about 10 s and finally washed several times with sterile distilled water. To confirm the success of the disinfection process, washed root segments were placed on R2A agar (Difco) for examination of bacterial growth after incubation at 28 u C for 5-6 days. After confirmation of the surface sterility of root segments, 1.0 g dried plant root was ground with a sterile mortar and pestle in 9.0 ml autoclaved filtered seawater (AFS). Serial dilutions were made using AFS and 200 ml aliquots of the 10 23 to 10 25 dilu...