A bacterial strain, designated 4GSKXT, isolated from the forest soil of Dinghushan Biosphere Reserve, Guangdong Province, PR China (112° 31' E 23° 10' N), is proposed as a novel species of the genus Acidicapsa. Cells of strain 4GSKXT were aerobic, non-motile, Gram-stain-negative short rods that multiplied by binary division. The strain grew at 12-37 °C (optimum, 25-30 °C), pH 4.0-6.5 (optimum, pH 4.5-5.0) and NaCl concentrations of 0-1.0 % (w/v; optimum, 0 %). Strain 4GSKXT utilized various carbon sources as growth substrates, including both sugars and amino acids. The major fatty acids (>10 %) were iso-C15 : 0 (48.8 %) and iso-C17 : 1ω9c/C16 : 0 10-methyl (14.7 %). The major polar lipids were phosphatidylethanolamine, an unidentified glycolipid, three unidentified phospholipids and two unidentified aminophospholipids. The only quinone detected was MK-8 and the DNA G+C content was 52.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 4GSKXT belongs to the genus Acidicapsa in the family Acidobacteriaceae in subdivision 1 of the phylum Acidobacteria, with the highest similarity of 97.1 % to Acidicapsa ligni WH120T. Based on all phenotypic, chemotaxonomic and phylogenetic data obtained, it is proposed as a novel species of genus Acidicapsa, for which the name Acidicapsa dinghuensis sp. nov. is proposed, with 4GSKXT (=CGMCC 1.15449T=LMG 29213T) as the type strain.
Keywords: Acidicapsa; acidophilic; phylogeny.