Dyella monticola sp. nov. and Dyella psychrodurans sp. nov., isolated from monsoon evergreen broad-leaved forest soil of Dinghu Mountain, China

Cells of bacterial strains 4 G-K06 T and 4MSK11 T , isolated from soil samples collected from monsoon evergreen broad-leaved forest of the Dinghushan Mountain (112° 31′ E 23° 10′ N), Guangdong Province, PR China, were Gram-stain-negative, aerobic, non-spore-forming, non-motile and rod-shaped. Strain 4 G-K06 T grew at 10–37 °C, pH 3.5–7.5 and 0–3.5 % (w/v) NaCl; while 4MSK11 T grew at 4–42 °C, pH 3.5–7.5 and 0–2.5 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed strain 4 G-K06 T formed a clade with Dyella flagellata 4 M-K16 T , Dyella acidisoli 4M-Z03 T , Dyella humi DHG40 T and Dyella nitratireducens DHG59 T , while strain 4MSK11 T formed a clade with Dyella caseinilytica DHOB09 T and Dyella mobilis DHON07 T , both within the genus Dyella . The result of the partial atpD , gyrB and lepA gene sequence analysis supported the conclusion based on 16S rRNA gene sequence analysis, which showed that these two strains represent two novel species of Dyella . The average nucleotide identity and digital DNA–DNA hybridization value for the whole genomes were 75.0–79.0 and 20.3–22.6 % between strains 4 G-K06 T , 4MSK11 T and those described Dyella species with genome sequences; while the DNA–DNA hybridization rates between strains 4 G-K06 T , 4MSK11 T and closely related Dyella species (without genome sequence) were 29.5–41.8 %. The major cellular fatty acids of these two strains were iso-C 15 : 0 , iso-C 16 : 0 and iso-C 17 : 1 ω 9 c , while the major polar lipids consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and several unidentified phospholipids and aminophospholipids. The only ubiquinone of these two strains was ubiquinone-8. The DNA G+C contents of 4 G-K06 T and 4MSK11 T were 60.4 and 61.3 mol%, respectively. On the basis of the evidence presented here, strains 4 G-K06 T and 4MSK11 T represent two novel species of the genus Dyella , for which the names Dyella monticola sp. nov. (type strain 4 G-K06 T =LMG 30268 T =GDMCC 1.1188 T ) and Dyella psychrodurans sp. nov. (type strain 4MSK11 T =KCTC 62280 T =GDMCC 1.1185 T ) are proposed.