Ramlibacter humi sp. nov., isolated from tropical forest soil

A Gram-stain-negative, aerobic and non-motile strain, designated 18x22-1(T), was isolated from a forest soil sample collected from Limushan Nature Reserve in Hainan Province, PR China. Growth occurred at 15-37 degrees C and pH 6.0-8.0 without NaCl. The 16S rRNA gene sequence analyses showed that strain 18x22-1(T )was closely related to Ramlibacter tataouinensis DSM 14655(T) (98.5 %), followed by Ramlibacter henchirensis DSM 14656(T) (97.9 %) and other Ramlibacter species and formed a stable cluster with R. tataouinensis DSM 14655(T), R. henchirensis DSM 14656(T) , Ramlibacter solisilvae JCM 19319(T) and Ramlibacter rhizophilus CCTCC AB 2015357(T). Results of chemotaxonomic analyses showed that ubiquinone-8 (Q-8) was the major respiratory quinone, and the major fatty acids (>10 % of the total amounts) were C-16:0 and C-17:0 cyclo. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, two unidentified aminopholipids and four unidentified phospholipids. The draft genome sequence was 4.47 Mb long with a G+C content of 68.9 mol%. The average nucleotide identity and digital DNA-DNA hybridization values between strain 18x22-1(T) and four closely related type strains were in the range of 79.3-82.3 % and 21.9-25.1 %, respectively. The results of phenotypic, phylogenetic and chemotaxonomic analyses supported that strain 18x22-1(T) represents a novel species of the genus Ramlibacter, for which the name Ramlibacter humi sp. nov. is proposed. The type strain is 18x22-1(T) (=GDMCC 1.1584(T) =KCTC 52922(T)).