Two strains, 4G-K17T and 4G-K15, were isolated from forest soil from the Dinghushan Biosphere Reserve, Guangdong Province, PR China (112° 31' E 23° 10' N). The cells of the two strains were Gram-stain-negative, aerobic and non-motile short rods that multiplied by binary division. Strains 4G-K17T and 4G-K15 were obligately acidophilic, mesophilic bacteria capable of growth at pH 3.0-7.0 (optimum 4.0-5.5 and 3.5-5.5, respectively), temperature 12-42 °C (optimum 28 °C) and NaCl concentrations from 0~2.5 % and 0~3.0 % (w/v), respectively. They had a 16S rRNA gene sequence similarity of 99.2 % and showed the highest similarities of 97.1 and 97.4 % to Edaphobacter aggregans Wbg-1T, respectively, which indicated that these two isolates belonged to a novel species of the genus Edaphobacter in subdivision 1 in the family Acidobacteriaceae. The DNA G+C contents of strains 4G-K17T and 4G-K15 were 57.6 and 57.2 %, respectively. They had similar fatty acid profiles, with the major (>10 %) fatty acid profile comprising iso-C15 : 0, C16 : 0 and summed feature 3 (iso-C16 : 1ω7c and/or C16 : 1ω6c), and the major polar lipid profile comprising phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, unidentified aminophospholipids and unidentified phospholipids. All physiological, phylogenetic and chemotaxonomic data suggest that strains 4G-K17T and 4G-K15 belong to a new species of the genus Edaphobacter, for which the name Edaphobacter acidisoli sp. nov. is proposed, with 4G-K17T (=CGMCC 1.15447=LMG 29212) as the type strain.
Keywords: Edaphobacter; acidophilic; phylogeny.