Nocardioides nematodiphilus sp. nov., isolated from rhizosphere of Arabidopsis thaliana.

An actinobacterial strain, designated R-N-C8T, was isolated from the rhizosphere soil of Arabidopsis thaliana collected in Yunnan Province, south-west China. Based on the results of 16S rRNA gene sequence analysis, strain R-N-C8T had highest similarity to Nocardioides terrae CGMCC 1.7056T (96.5%), Nocardioides opuntiae KCTC 19804T (96.3%) and Nocardioides currus IB-3T (96.1%), and lower than 96.0 % similarity to other members of the genus Nocardioides. Phylogenetic trees based on 16S rRNA gene sequences indicated that strain R-N-C8T formed an isolated branch with N. terrae CGMCC 1.7056T and N. opuntiae KCTC 19804T. The polar lipids contained phosphatidylglycerol, diphosphatidylglycerol, one unidentified phosphoglycolipid and four unidentified phospholipids in the cellular membrane. The major fatty acids were identified as iso-C16 : 0, anteiso-C17 : 0, iso-C17 : 0, summed feature 9 (iso-C17 : 1 ω9c and/or C16 : 0 10-methyl) and iso-C15 : 0. The predominant respiratory quinone was MK-8(H4) and ll-diaminopimelic acid was the diagnostic diamino acid in the cell-wall peptidoglycan. The genomic DNA G+C content was 70.9 mol%. The orthologous average nucleotide identiy values between N. terrae CGMCC 1.7056T, N. currus IB-3T and strain R-N-C8T were 77.1 and 75.1 %, respectively. DNA-DNA hybridization values between N. terrae CGMCC 1.7056T, N. currus IB-3T and strain R-N-C8T were 20.7 and 19.9 % respectively. Data from phenotypic and genotypic analyses supported that strain R-N-C8T represents a new species of Nocardioides, for which the name Nocardioides nematodiphilus sp. nov. is proposed. The type strain is R-N-C8T (=CGMCC 1.18723T= KCTC 49528T).

Sphingobacterium lumbrici sp. nov., a novel bacterium isolated from wormcast of Eisenia foetida.

A novel Gram-stain-negative, rod-shaped, non-motile, yellowish bacterium, designated strain 1.3611T, was isolated from the wormcast of Eisenia foetida. The strain grew optimally at 30-37 ℃, at pH 7.0 and with 0-1.0 % (w/v) NaCl. Based on the results of 16S rRNA gene sequence and phylogenetic analyses, strain 1.3611T showed the highest degree of 16S rRNA gene sequence similarity to Sphingobacterium olei HAL-9T (97.0 %), followed by Sphingobacterium alkalisoli Y3L14T (95.8 %). The respiratory quinone of strain 1.3611T was menaquinone-7 (MK-7) and its major cellular fatty acids were iso-C15 : 0 (41.3 %), summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c, 22.1 %) and iso-C17 : 0 3-OH (16.2 %). The major polar lipids were sphingophospholipid, phosphatidylethanolamine, four unidentified glycolipids, two unidentified phospholipids and five unidentified polar lipids. The genomic DNA G+C content was 39.0 mol%. The digital DNA-DNA hybridization and average nucleotide identity values between the genomes of strain 1.3611T and S. olei HAL-9T were 37.9 and 88.9 %, respectively. According to the phenotypic and chemotaxonomic phylogenetic results, strain 1.3611T should represent a novel species of the genus Sphingobacterium, for which the name Sphingobacterium lumbrici sp. nov. is proposed, with strain 1.3611T (=KCTC 62980T=CCTCC AB 2018349T) as the type strain.

Luteimonas lumbrici sp. nov., a novel bacterium isolated from wormcast.

A Gram-stain-negative, yellow-green bacterium, designated 1.1416T, was isolated from wormcast of Eisenia foetida. The strain was non-motile, rod-shaped, and grew optimally on NA medium at 30 °C, pH 7.0 and with 0 % (w/v) NaCl. On the basis of the 16S rRNA gene sequence and phylogenetic analysis, 1.1416T showed the highest degree of 16S rRNA gene sequence similarity to Luteimonas arsenica 26-35T (96.2 %), followed by Luteimonas lutimaris G3T (96.1 %). The respiratory quinone of 1.1416T was ubiquinone-8 (Q-8), and its major cellular fatty acids were iso-C15 : 0 (39.8 %), summed feature 9 (iso-C17 : 1 ω9c or C16 : 0 10-methyl) (18.6 %). The major polar lipids of 1.1416T were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and six unidentified phospholipids. The genomic DNA G+C content of 1.1416T was 71.0 mol%. According to the results of the phenotypic and chemotaxonomic phylogenetic analyses, strain 1.1416T represents a novel species of the genus Luteimonas, for which the name Luteimonas lumbrici sp. nov. is proposed, with strain 1.1416T (=KCTC 62979T=CCTCC AB 2018348T) as the type strain.

Asticcacaulis tiandongensis sp. nov., a new member of the genus Asticcacaulis, isolated from a cave soil sample.

A Gram-stain negative, aerobic, motile and rod-shaped bacterium, designated strain 3.1105T, was isolated from a karst district soil sample collected from Tiandong cave, Guizhou province, south-west PR China. The isolate grew at 10-40 °C and pH 5.0-8.0 and tolerated up to 1 % NaCl (w/v) on R2A medium, with optimal growth at 25-30 °C, pH 7.0 and 0 % NaCl (w/v). Cells showed oxidase-positive and catalase-positive reactions. The respiratory quinone was Q-10. The predominant cellular fatty acids contained C18 : 1ω7c 11-methyl, summed feature 8 (C18 : 1ω7c or C18 : 1ω6c), C16 : 0 and C17 : 0. The major polar lipids were phosphatidylglycerol and monoglycosyldiglycerides. The genomic DNA G+C content was 56.0 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that 3.1105T should be affiliated to the genus Asticcacaulis and showed highest 16S rRNA gene sequence similarity values with Asticcacaulis excentricus CB 48T (96.0 %), Asticcacaulis endophyticus ZFGT-14T (95.3 %) and lower than 95.3 % similarity to other species of the genus Asticcacaulis. The polyphasic taxonomic characteristics indicated that strain 3.1105T represents a novel species of the genus Asticcacaulis, for which the name Asticcacaulis tiandongensis sp. nov., (type strain 3.1105T=KCTC 62978T=CCTCC AB 2018268T) is proposed.

Sphingobacterium cavernae sp. nov., a novel bacterium isolated from soil sampled at Tiandong Cave.

A Gram-stain-negative, non-motile and rod-shaped bacterium, designated strain 5.0403-2T, was isolated from a cave soil sample collected from Tiandong Cave, Guizhou Province, south-west PR China. Cells showed positive oxidase and catalase reactions. The predominant isoprenoid quinone was MK-7. The major fatty acids were identified as iso-C15 : 0, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), iso-C17 : 0 3OH and summed feature 9 (iso-C17 : 1 ω9c or C16 : 0 10-methyl). The cellular polar lipids contained phosphatidylethanolamine, one unidentified phospholipid, three unidentified phosphoglycolipids and four unidentified lipids. The genomic DNA G+C content was 36.0 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 5.0403-2T should be assigned to the genus Sphingobacterium. Results of 16S rRNA gene sequence similarity analysis showed that strain 5.0403-2T was most similar to Sphingobacterium bovisgrunnientis KCTC 52685T (98.7 %), Sphingobacterium composti KCTC 12578T (98.0 %) and Sphingobacterium alimentarium DSM 22362T (97.3 %) and less than 95.0 % similar to other species of the genus Sphingobacterium. The average nucleotide identity values between strain 5.0403-2T and S. bovisgrunnientis KCTC 52685T, S. composti KCTC 12578T and S. alimentarium DSM 22362T were 94.2, 82.3 and 77.2 % respectively. The digitalDNA-DNA hybridization values between strain 5.0403-2T and S. bovisgrunnientis KCTC 52685T, S. composti KCTC 12578T and S. alimentarium DSM 22362T were 68.4, 25.6 and 20.7 %. These results indicated that the isolate represented a novel genomic species. The polyphasic taxonomic characteristics indicated that strain 5.0304-2T represents a novel species of the genus Sphingobacterium, for which the name Sphingobacterium cavernae sp. nov. (type strain 5.0403-2T=KCTC 62981T=CCTCC AB 2019257T) is proposed.