Paraburkholderia pallida sp. nov. and Paraburkholderia silviterrae sp. nov., isolated from forest soil

Two Gram-stain-negative, aerobic, motile, white-pigmented and rod-shaped bacterial strains, 7MH5(T) and 4 M-K11(T), were isolated from forest soil of Dinghushan Biosphere Reserve, Guangdong Province, PR China. Strain 7MH5(T) grew at 4-37 degrees C (optimum, 28-33 degrees C), pH 3.5-9.0 (pH 4.0-5.5) and in the presence of 0-3 % (w/v) NaCl (0-1.5 w/v); while strain 4 M-K11(T) grew at 4-42 degrees C (20-33 degrees C), pH 3.5-8.5 (pH 4.5-6.0) and in the presence of 0-2.5 % (w/v) NaCl (0-1.5 w/v). Strains 7MH5(T) and 4 M-K11(T) have the highest 16S rRNA gene sequence similarities of 98.6 and 98.7 % to Paraburkholderia peleae PP52-1(T), and 98.4 % between themselves. In the 16S rRNA gene sequence phylogram, strains 4 M-K11(T) and Paraburkholderia ferrariae NBRC 106233(T) formed a clade while 7MH5(T) were relatively distinct from other Paraburkholderia species. Based on the UBCG phylogenomic analysis, strains 7MH5(T) and 4 M-K11(T) formed a clade with Paraburkholderia oxyphila NBRC 105797(T) and Paraburkholderia sacchari LMG 19450(T) in the genus of Paraburkholderia . The DNA G+C contents of strains 7MH5(T) and 4 M-K11(T) were 64.2 and 64.3 %, respectively. Digital DNA-DNA hybridization and the average nucleotide identity values of strains 7MH5(T), 4 M-K11(T) and closely related strains were in the ranges of 25.2-63.6 % and 81.0-95.5 %, respectively. The two strains had the same major respiratory quinone: ubiquinone-8. Strain 7MH5(T) had C-16:0, C(17:0)cyclo, C(19:)(0)cyclo omega 8c and summed feature 8 (C-18:1 omega 7c/C-18:1 omega 6c) as its major fatty acids, while strain 4 M-K11(T) had major fatty acids of C-16:0, C(17:0)cyclo and summed feature 2 (iso-C-16:1 I/C-14: 0-3OH). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. On the basis of phenotypic and phylogenetic analyses based on both 16S rRNA gene and whole genome sequences, as well as chemotaxonomic data, strains 7MH5(T) and 4 M-K11(T) represent two novel species of the genus Paraburkholderia, for which the names Paraburkholderia pallida sp. nov. (type strain 7MH5(T)=GDMCC 1.1450(T)=KACC 19962(T)) and Paraburkholderia silviterrae sp. nov. (type strain 4 M-K11(T)=GDMCC 1.1284(T)=CGMCC 1.15450(T)=KACC 19961(T)=LMG 29217(T)) are proposed.