Dyella caseinilytica sp. nov., Dyella flava sp. nov. and Dyella mobilis sp. nov., isolated from forest soil.

Three strains, DHOB09T, DHOC52T and DHON07T, were isolated from the forest soil of Dinghushan Biosphere Reserve, Guangdong Province, PR China. They were all Gram-stain-negative, aerobic, rod-shaped cells. The ranges (optimum) for the temperature, pH and NaCl concentration for growth of DHOB09T, DHOC52T and DHON07T were 10-42 (25-28) °C, pH 5.5-9.0 (7.0-7.5) and 0-4.0 (0-0.5) % (w/v); 10-42 (28) °C, pH 4.0-7.0 (4.5-6.5) and 0-2.0 (0) % (w/v) and 10-37 (25-28) °C, pH 4.0-7.5 (5.5-6.0) and 0-2.5 (0)  % (w/v), respectively. Phylogenetic analysis based on 16S rRNA gene sequences showed that DHOB09T, DHOC52T and DHON07T formed a phyletic cluster with seven species of the genus Dyella within the major clade of Dyella with sequence similarities ranged from 96.9 to 98.6 %. This indicated that the three strains may represent three novel species of the genus Dyella. This result was also strongly supported by the concatenated analysis of partial gyrB, lepA and recA gene sequences. DNA-DNA hybridization between strains DHON07T and DHOB09T, as well as DHON07T and Dyella koreensis BB4T was much lower than 70 %. The G+C content of strains DHOB09T, DHOC52T and DHON07T were 59.4, 60.7 and 59.5 %, respectively. The major fatty acids of the three strains were iso-C15 : 0, iso-C16 : 0 and iso-C17 : 0 and the predominant respiratory lipoquinone was ubiquinone-8. All of the physiological, phylogenetic and chemotaxonomic data showed that strains DHOB09T, DHOC52T and DHON07T are distinctive from each other and from all species of the genus Dyellawith validly published names. Therefore, we suggest that they represent three novel species of the genus, for which the names Dyella caseinilytica sp. nov. (type strain DHOB09T=CGMCC 1.15434T=LMG 29202T), Dyella flava sp. nov. (type strain DHOC52T=NBRC 111979T=KCTC 52128T) and Dyella mobilis sp. nov. (type strain DHON07T=CGMCC 1.15400T=NBRC 111475T) are proposed.