Burkholderia diazotrophica sp. nov., isolated from root nodules of Mimosa spp

Five strains, JPY461T, JPY359, JPY389, DPU-3 and STM4206 were isolated from nitrogen-fixing nodules on the roots of Mimosa spp. and their taxonomic positions were investigated using a polyphasic approach. All five strains grew at 15–40 °C (optimum, 30–37 °C), at pH 4.0–8.0 (optimum, pH 6.0–7.0) and with 0–1 % (w/v) NaCl [optimum, 0 % (w/v)]. On the basis of 16S rRNA gene sequence analysis, a representative strain (JPY461T) showed 97.2 % sequence similarity to the closest related species Burkholderia acidipaludis SA33T, a similarity of 97.2 % to Burkholderia terrae KMY02T, 97.1 % to Burkholderia phymatum STM815T and 97.1 % to Burkholderia hospita LMG 20598T. The predominant fatty acids of the five novel strains were summed feature 2 (comprising C16 : 1 iso I and/or C14 : 0 3-OH), summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 , C16 : 0 3-OH, C17 : 0 cyclo, C18 : 1ω7c and C19 : 0 cyclo ω8c. The major isoprenoid quinone was Q-8 and the DNA G+C content of the strains was 63.0–65.0 mol%. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified aminophospholipid, an unidentified aminolipid and several unidentified phospholipids. The DNA–DNA relatedness of the novel strain with respect to recognized species of the genus Burkholderia was less than 54 %. On the basis of 16S rRNA and recA gene sequence similarities, chemotaxonomic and phenotypic data, the five strains represent a novel species in the genus Burkholderia, for which the name Burkholderia diazotrophica sp. nov. is proposed with the type strain, JPY461T ( = LMG 26031T = BCRC 80259T = KCTC 23308T).