A Gram-stain-positive, rod-shaped, endospore-forming, motile bacterium, designated D33T , was isolated from a forest soil sample. The strain grew optimally at 30-37 8C, pH 8.0 and with 1 % (w/v) NaCl. The 16S rRNA gene sequence of the isolate showed similarities lower than 97 % with respect to species of the genus Paenibacillus. Strain D33 T contained meso-diaminopimelic acid in the cell-wall peptidoglycan, and ribose and lower amounts of glucose and galactose as the whole-cell sugars. The major cellular fatty acid was anteiso-C 15 : 0 , and menaquinone-7 (MK-7) was the only respiratory quinone. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylmethylethanolamine, two glycolipids and an unknown lipid. The DNA G+C content was 51.1 mol%. The genus Paenibacillus, a member of the family Paenibacillaceae, was proposed by Ash et al. (1993Ash et al. ( , 1994. At the time of writing, there are 168 species with validly published names (http://www.bacterio.net/paenibacillus.html). Most members of the genus Paenibacillus are aerobic or facultatively anaerobic, rod-shaped, endospore-forming bacteria. The major cellular fatty acid is anteiso-C 15 : 0 and menaquinone-7 (MK-7) is the major menaquinone. The DNA G+C content is in the range of 39 to 54 mol% (Wang et al., 2012). Species of the genus Paenibacillus have been isolated from various environmental sources, such as soil, air, a sandbank, blood cultures, rhizosphere and plants (Ten et al., 2006;Rivas et al., 2005;Traiwan et al., 2011;Roux & Raoult, 2004;Kittiwongwattana & Thawai, 2015;Cao et al., 2015;Jiang et al., 2015;Xiang et al., 2014).In this study, the taxonomic characterization of strain D33 T using a polyphasic approach is reported and in conclusion, a novel species of genus Paenibacillus is proposed.
Strain D33T was isolated from a forest soil sample and purified on a sucrose-mineral salts medium as described previously (Huang et al., 2014(Huang et al., , 2015. The isolate was maintained on trypticase soy agar [TSA, comprising trypticase soy broth (TSB) supplemented with 15 g Bacto Agar (Difco)]. The morphology of cells, spores and motility was examined by light microscopy (CX21; Olympus). The presence of flagellum was examined by transmission electron microscopy (TEM, H-7650; Hitachi) using cells from the exponential phase. The morphology and size of colonies were observed on sucrose-mineral salts medium and TSA plates after 2 days at 30 8C. Growth at different temperatures (4, 10, 20, 30, 37, 42, 45, 50 and 55 8C) was determined on TSA in an aerobic incubator. TSB was used in experiments to determine growth at pH 4-10 (at intervals of 1 pH unit; the pH was adjusted with HCl or Na 2 CO 3 ) and the requirement for NaCl (0-5 %, w/v, at intervals of 1.0 %). Catalase activity was determined according to bubble production in a 3 % (v/v) hydrogen peroxide solution. Oxidase activity was determined based Abbreviations: DPG, diphosphatidylglycerol; PE, phosphatidylethanolamine; PG, phosphatidylglycerol; PME, phosph...