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-K06T and 4MSK11T, 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-K06T grew at 10-37 °C, pH 3.5-7.5 and 0-3.5 % (w/v) NaCl; while 4MSK11T 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-K06T formed a clade with Dyellaflagellata 4 M-K16T, Dyella acidisoli 4M-Z03T, Dyellahumi DHG40T and Dyellanitratireducens DHG59T, while strain 4MSK11T formed a clade with Dyellacaseinilytica DHOB09T and Dyellamobilis DHON07T, 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-K06T, 4MSK11T and those described Dyella species with genome sequences; while the DNA-DNA hybridization rates between strains 4 G-K06T, 4MSK11T and closely related Dyella species (without genome sequence) were 29.5-41.8 %. The major cellular fatty acids of these two strains were iso-C15 : 0, iso-C16 : 0 and iso-C17 : 1ω9c, 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-K06T and 4MSK11T were 60.4 and 61.3 mol%, respectively. On the basis of the evidence presented here, strains 4 G-K06T and 4MSK11T represent two novel species of the genus Dyella, for which the names Dyella monticola sp. nov. (type strain 4 G-K06T=LMG 30268T=GDMCC 1.1188T) and Dyella psychrodurans sp. nov. (type strain 4MSK11T=KCTC 62280T=GDMCC 1.1185T) are proposed.

Dyella acidisoli sp. nov., D. flagellata sp. nov. and D. nitratireducens sp. nov., isolated from forest soil.

Bacterial strains 4M-Z03T, 4M-K16T and DHG59T were isolated from forest soil samples collected from the Dinghushan Biosphere Reserve, Guangdong Province, PR China (112° 31' E 23° 10' N). The three strains grew well at 28 °C, pH 5.0-6.0 on R2A medium. On the basis of 16S rRNA gene sequence analysis, the three strains, together with Dyella humi DHG40T, formed a distinct phyletic clade within the genus Dyella, and the sequence similarities between any strains of the clade ranged from 97.8 to 98.5 %. Sequence analysis of concatenated partial gyrB, lepA and recA gene sequences also strongly suggested that the three strains represented three novel species of the genus Dyella. The respiratory lipoquinone of the three strains was ubiquinone-8, and their DNA G+C content was 58.2-59.0 mol%. The fatty acid profiles differed substantially among these three strains, although they had two common major fatty acids, iso-C15 : 0 and iso-C17 : 1ω9c. The DNA-DNA relatedness among the three strains and the type strains of the closest species of the genus Dyella examined was lower than 50 %. The results of genotypic and phenotypic characterization presented above demonstrate that the three strains examined represent three novel species of the genus Dyella, for which the names Dyella acidisoli sp. nov. (type strain 4M-Z03T=NBRC 111980T=KCTC 52131T), Dyella flagellata sp. nov. (type strain 4M-K16T=NBRC 111981T=KCTC 52130T) and Dyella nitratireducens sp. nov. (type strain DHG59T=NBRC 111472T=LMG 29201T=CGMCC 1.15439T) are proposed.

Aliidongia dinghuensis gen. nov., sp. nov., a poly-ß-hydroxybutyrate-producing bacterium isolated from Pinus massoniana forest soil.

A Gram-stain-negative, aerobic, motile, rod-shaped bacterium, designated 7M-Z19T, was isolated from a soil sample collected from a Pinus massoniana forest of Dinghushan Biosphere Reserve, Guangdong Province, PR China. Strain 7M-Z19T grew at pH 4.5-7.5 (optimum pH 6.0-6.5), 10 to 37 °C (optimum 28 °C) and NaCl concentration up to 2.0 % (optimum 0 %, w/v). iso-C17 : 0, C18 : 1ω7c and C19 : 0ω8c cyclo were the major fatty acids (>10 %) while ubiquinone-10 was the only respiratory quinone detected in 7M-Z19T. The polar lipids of the strain consisted of phosphatidylethanolamine, phosphatidyldimethylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, six unidentified aminophospholipids, three unidentified phospholipids, six unidentified lipids and a glycolipid. The DNA G+C content was 65.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the isolate formed a distinct lineage with Dongia mobilis and Dongia rigui within the family Rhodospirillaceae, but with a low sequence similarity of 92.7 and 92.0 %, respectively. On the basis of phylogenetic, phenotypic, physiological and chemotaxonomic distinctiveness, strain 7M-Z19T should be placed in the family Rhodospirillaceae as a representative of a novel genus and species, for which the name Aliidongia dinghuensis gen. nov., sp. nov., is proposed. The type strain of the type species is 7M-Z19T (=NBRC 112240T=KCTC 52134T=CGMCC 1.15725T).