Nocardioides limicola sp. nov., an alkaliphilic alkane degrading bacterium isolated from oilfield alkali-saline soil

A Gram-stain-positive, rod-shaped, non-spore-forming, alkane degrading bacterium, designated DJM-14T, was isolated from oilfield alkali-saline soil in Heilongjiang, Northeast China. On the basis of 16 S rRNA gene sequencing, strain DJM-14T was shown to belong to the genus Nocardioides, and related most closely to Nocardioides terrigena KCTC 19,217T (95.53% 16 S rRNA gene sequence similarity). Strain DJM-14T was observed to grow at 25-35 °C, pH 7.0-11.0, in the presence of 0-6.0% (w/v) NaCl. The predominant respiratory quinone was MK-8 (H4) and LL-diaminopimelic acid was the diagnostic diamino acid in the cell-wall peptidoglycan. The major fatty acids were identified as iso-C16:0 and C18:1 ω9c. It contained diphosphatidylglycerol, phosphatidylglycerol and phosphatidylinositol as the polar lipids. The genome (3,722,608 bp), composed of 24 contigs, had a G + C content of 69.6 mol%. Out of the 3667 predicted genes, 3618 were protein-coding genes, and 49 were ncRNAs. Digital DNA-DNA hybridization (dDDH) estimation and average nucleotide identity (ANI) of strain DJM-14T against genomes of the type strains of related species in the same family ranged between 18.7% and 20.0%; 68.8% and 73.6%, respectively. According to phenotypic, genotypic and phylogenetic data, strain DJM-14T represents a novel species in the genus Nocardioides, for which the name Nocardioides limicola sp. nov. is proposed and the type strain is DJM-14T (= CGMCC 4.7593T, =JCM 33,692T). In addition, novel strains were able to grow with n-alkane (C24-C36) as the sole carbon source. Multiple copies of alkane 1-monooxygenase (alkB) gene, as well as alcohol dehydrogenase gene and aldehyde dehydrogenase gene involved in the alkane assimilation were annotated in the genome of type strain DJM-14T.

Nocardioides coralli sp. nov., an actinobacterium isolated from stony coral in the South China Sea

A Gram-stain-positive, aerobic, non-pigmented and non-motile actinobacterium, designated strain SCSIO 67246T, was isolated from a stony coral sample collected from the Sanya sea area, Hainan province, China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain SCSIO 67246T shared the highest similarities with Nocardioides rotundus MCCC 1A10561T (96.5 %) and Nocardioides sonneratiae KCTC 39565T (96.1%). The novel strain grew at 15–37 °C, at pH 5.0–10.0 and in the presence of 0–10 % (w/v) NaCl. The genome length of strain SCSIO 67246T was 3.52 Mbp with a DNA G+C content of 72.0 mol% and 3397 protein-coding genes. The novel strain showed an average nucleotide identity value of 76.5 % and a digital DNA–DNA hybridization value of 20.1 % with N. rotundus MCCC 1A10561T. Strain SCSIO 67246T contained MK-8(H4) as the major menaquinone. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and five phospholipids. The major cellular fatty acids were iso-C16 : 0, C17 : 1 ω8c and summed feature 9 (iso-C17 : 1 ω9c/10-methyl C16 : 0). ll-2,6-Diaminopimelic acid was the diagnostic diamino acid. The whole-cell sugars were galactose, glucose and ribose. Based on this polyphasic taxonomic study, strain SCSIO 67246T represents a novel species of the genus Nocardioides , for which the name Nocardioides coralli sp. nov. is proposed. The type strain is SCSIO 67246T (=MCCC 1K06251T=KCTC 49719T).

Nocardioides dongkuii sp. nov. and Nocardioides lijunqiniae sp. nov., isolated from faeces of Tibetan antelope (Pantholops hodgsonii) and leaves of dandelion (Taraxacum officinale), respectively, on the Qinghai-Tibet Plateau

In the present study, four bacterial strains, two (S-713^T and 406) isolated from faecal samples of Tibetan antelopes and the other two (S-531^T and 1598) from leaves of dandelion collected on the Qinghai-Tibet Plateau of PR China, were analysed using a polyphasic approach. All four isolates were aerobic, rod-shaped, non-motile, oxidase-negative, Gram-stain-positive and catalase-positive. According to four phylogenetic trees, strain pairs S-713^T/406 and S-531^T/1598 form two independent branches belonging to the genus Nocardioides, and are closest to Nocardioides lianchengensis, Nocardioides dokdonensis, Nocardioides salarius, Nocardioides marinisabuli, Nocardioides psychrotolerans and Nocardioides szechwanensis. Although sharing MK8-(H₄) as their major isoprenoid quinone, strains S-713^T and S-531^T contained C_18 : 1  ω9c (24.64 and 16.34 %) and iso-C_16 : 0 (9.74 and 29.38 %), respectively, as their main fatty acids, with remarkable differences in their biochemical profiles but only slight ones in their optimal growth conditions. The chromosomes of strains S-713^T and S-531^T were 4 207 844 bp (G+C content, 73.0 mol%) and 4 809 817 bp (G+C content, 72.5 mol%), respectively. Collectively, the two strain pairs represent two separate novel species of the genus Nocardioides, for which the names Nocardioides dongkuii sp. nov. and Nocardioides lijunqiniae sp. nov. are proposed, with S-713^T (=JCM 33698^T=CGMCC 4.7660^T) and S-531^T (=JCM 33468^T=CGMCC 4.7659^T) as the respective type strains.

Lunatibacter salilacus gen. nov., sp. nov., a member of the family Cyclobacteriaceae, isolated from a saline and alkaline lake sediment

A non-motile, Gram-staining negative, catalase- and oxidase-positive, crescent-rod shaped bacterium, designated strain CUG 91308^T, was isolated from a sediment sample of Qinghai Lake, Qinghai Province, China. Colonies on OSM agar were round, smooth, flat and pinkish-orange in colour. Strain CUG 91308^T could grow at 15-37 °C, pH 6-12 and in the presence of up to 7.0 % NaCl (w/v). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CUG 91308^T belonged to the family Cyclobacteriaceae and formed a clade with the genus Lunatimonas in the phylogenetic tree, but separated from any species of the known genera within the family. The genomic DNA G+C content is about 42.1 %. The predominant fatty acids (>10 %) were iso-C_15 : 0 (21.1 %), summed feature 3 (C_16 : 1  ω7c / C_16 : 1  ω6c / iso-C_15 : 0 2OH) (14.3 %), iso-C_17 : 0 3OH (12.3 %) and summed feature 9 (iso-C_17 : 1  ω9c / C_16 : 0 10-methyl) (10.6 %). The polar lipids of strain CUG 91308^T were phosphatidylethanolamine (PE) and four unidentified polar lipids. Strain CUG 91308^T contained MK-7 as the major respiratory quinone. On the basis of phenotypic, genotypic and phylogenetic data, strain CUG 91308^T represents a novel species of a novel genus in the family Cyclobacteriaceae, for which the name Lunatibacter salilacus gen. nov., sp. nov. is proposed. The type strain of the proposed new isolate is CUG 91308^T (=KCTC 62636^T=CGMCC 1.13593^T).

Nocardioides stalactiti sp. nov., isolated from a cave stalactite surface

An aerobic, rod-shaped, Gram-stain-positive, actinobacterial strain, designated 1.0914^T, was isolated from a stalactite sample collected from a cave located in Guizhou Province, southwest PR China. Based on 16S rRNA gene sequence analysis, strain 1.0914^T shared highest similarities values with Nocardioides pelophilus CGMCC 4.7388^T (97.7 %), Nocardioides immobilis CCTCC AB 2017083^T (97.5 %) and Nocardioides silvaticus CCTCC AB 2018079^T (97.3 %) and values lower than 97.0 % to other members of the genus Nocardioides. Phylogenetic trees based on 16S rRNA gene sequences indicated that strain 1.0914^T formed an isolated branch with N. pelophilus CGMCC 4.7388^T, N. immobilis CCTCC AB 2017083^T and N. silvaticus CCTCC AB 2018079^T. The polar lipids contained phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol and one unidentified phospholipid in the cellular membrane. The major fatty acids were identified as iso-C_16 : 0, C_18 : 1 ω9c, C_17 : 1 ω8c and C_16 : 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 71.1 mol%. The orthologous average nucleotide identiy values between N. pelophilus CGMCC 4.7388^T, N. immobilis CCTCC AB 2017083^T, N. silvaticus CCTCC 2018079^T and strain 1.0914^T were 82.3, 81.7 and 81.9 % respectively. DNA-DNA hybridization values between N. pelophilus CGMCC 4.7388^T, N. immobilis CCTCC AB 2017083^T, N. silvaticus CCTCC 2018079^T and strain 1.0914^T were 25.2, 24.6 and 24.5 % respectively. The phylogenetic, phenotypic and chemotaxonomic data supported the classification of strain 1.0914^T as representing a new species of Nocardioides, for which the name Nocardioides stalactiti sp. nov. is proposed. The type strain is 1.0914^T (=CCTCC AB 2018266^T=KCTC 49243^T).

Azoarcus halotolerans sp. nov., a novel member of Rhodocyclaceae isolated from activated sludge collected in Hong Kong

A floc-forming bacterial strain, designated HKLI-1^T, was isolated from the activated sludge of a municipal sewage treatment plant in Hong Kong SAR, PR China. Cells of this strain were Gram-stain-negative, strictly aerobic, catalase- and oxidase-positive, rod-shaped and motile by means of a single polar flagellum. Growth occurred at 18-37 °C (optimum, 28 °C), pH 5.5-9.0 (optimum, pH 7.5) and with 0-8.0 % (w/v) NaCl (optimum, 1-1.5 %) concentration. The major fatty acids of strain HKLI-1^T were C_16 : 0 and summed feature 3 (C_16 : 1 ω7c and/or C_16 : 1 ω6c). The polar lipid profile contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and three unidentified lipids. The DNA G+C content was 63.5 mol% from whole genomic sequence analysis. Based on the results of 16S rRNA gene sequences analysis, this strain should be assigned to the genus Azoarcus and is closely related to Azoarcus olearius DQS-4^T (94.93 % 16S rRNA gene sequence pairwise similarity), Azoarcus toluclasticus MF63^T (94.91 %) and Azoarcus communis SWub3^T (94.01 %), but separate from them by large distances in different phylogenetic trees. Based on whole genome analysis, the orthologous average nucleotide identity and in silico DNA-DNA hybridization values against four of the closest relatives were 73.03-74.83 and 17.2-23.0 %, respectively. The phylogenetic, genotypic, phenotypic and chemotaxonomic data demonstrated that strain HKLI-1^T could be distinguished from its phylogenetically related species, and that this strain represented a novel species within the genus Azoarcus, for which the name Azoarcus halotolerans sp. nov. is proposed. The type strain is HKLI-1^T (= 72659^T=CCTCC AB 2019312^T).

Nocardioides vastitatis sp. nov., isolated from Taklamakan desert soil

A Gram-stain-positive, aerobic, non-motile, rod-shaped actinobacterium, designated strain 21Sc5-5^T, was isolated from a soil sample collected in the Taklamakan desert in Xinjiang Uygur Autonomous Region, PR China and investigated by using a polyphasic approach. Strain 21Sc5-5^T grew at 10-37 °C (optimum, 28-30 °C), pH 6.0-9.0 (optimum, pH 7.0) and in the presence of 0-3 % (w/v) NaCl (optimum, 0 %). Phylogenetic analysis based on 16S rRNA gene sequences suggested that strain 21Sc5-5^T formed a distinct lineage within the genus Nocardioides and had the highest similarity to Nocardioides albidus THG-S11.7^T (97.30 %), followed by Nocardioides kongjuensis A2-4^T (97.22 %), Nocardioides nitrophenolicus NSP 41^T (97.15 %) and Nocardioides caeni MN8^T (97.15 %). The results of chemotaxonomic analyses showed that the isolate possessed ll-diaminopimelic acid as the diagnostic diamino acid of the peptidoglycan and MK-8(H₄) as the predominant menaquinone. The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, an unidentified phospholipid and three unidentified lipids. The major fatty acids were iso-C_16 : 0 and 10-methyl C_18 : 0. The genome length of strain 21Sc5-5^T was 4.67 Mb containing 372 contigs and with a DNA G+C content of 70.4 mol%. On the basis of data from phylogenetic, phenotypic and chemotaxonomic analyses, strain 21Sc5-5^T represents a novel species of the genus Nocardioides, for which the name Nocardioides vastitatis sp. nov. is proposed. The type strain is 21Sc5-5^T (=JCM 33365^T=CGMCC 4.7608^T).

Nocardioides ferulae sp. nov., isolated from root of an endangered medicinal plant Ferula songorica Pall. ex Spreng

A novel endophytic bacterium, designated strain SZ4R5S7^T, was isolated from surface-sterilized root of an endangered medicinal plant (Ferula songorica Pall. ex Spreng) collected from Xinjiang, north-west China. The taxonomic position of the strain was investigated by using a polyphasic approach. The strain was found to be aerobic, Gram-stain-positive, oxidase-negative and catalase-positive, short rods and non-motile. Strain SZ4R5S7^T grew at 4-37 °C (optimum, 28 °C), pH 5.0-9.0 (pH 6.0-8.0) and in the presence of 0-4 % (w/v) NaCl. The polar lipids detected for strain SZ4R5S7^T were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol and two unidentified lipids. The predominant menaquinone of strain SZ4R5S7^T was MK-8(H4), and the major fatty acids were iso-C16 : 0 and anteiso-C14 : 0. The DNA G+C content was determined to be 72.4 mol%. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain SZ4R5S7^T belongs to the genus Nocardioides and showed highest levels of 16S rRNA gene sequence similarity to members of the strain Nocardioideskribbensis KSL-2^T (97.8 %). On the basis of phenotypic, genotypic and phylogenetic data, strain SZ4R5S7^T represents a novel species in the genus Nocardioides, for which the name Nocardioides ferulae sp. nov. is proposed and the type strain is SZ4R5S7^T (=CGMCC 4.7456^T=KCTC 39994^T).

Nocardioides speluncae sp. nov., a novel actinobacterium isolated from a karstic subterranean environment sample

A novel actinobacterial strain, designated YIM ART13^T, was isolated from a soil sample collected from a karst cave in Xingyi county, Guizhou province, South western China. The taxonomic position of the strain was investigated using a polyphasic approach. Cells of the strain were found to aerobic and Gram-stain positive. On the basis of 16S rRNA gene sequence analysis, strain YIM ART13^T was found to be closely related to Nocardioides pakistanensis NCCP 1340^T (96.1% sequence similarity) and is therefore considered to represent a member of the genus Nocardioides. In addition, LL-diaminopimelic acid was identified as the diagnostic diamino acid in the cell wall peptidoglycan. The whole cell sugars were found to be mannose, galactose, glucose and ribose. The major isoprenoid quinone was identified as MK-8(H₄), while the major fatty acids (> 10%) were identified as iso-C_16:0, C_18:1ω9c and C_18:0 10-methyl. The polar lipids were found to contain diphosphatidylglycerol, phosphatidylglycerol phosphatidylinositol and phosphatidylinositol mannoside, an unidentified phospholipid. The genomic DNA G+C content of strain YIM ART13^T was determined from the draft genome sequence to be 70.1 mol%. On the basis of phenotypic, genotypic and phylogenetic data, strain YIM ART13^T represents a novel species of the genus Nocardioides, for which the name Nocardioides speluncae sp. nov. is proposed. The type strain is YIM ART13^T (= KCTC 39593^T = DSM 100493^T).