Nocardioides bizhenqiangii sp. nov. and Nocardioides renjunii sp. nov., isolated from soil and faeces of Tibetan antelope (Pantholops hodgsonii) on the Qinghai-Tibet Plateau.

Two novel strain pairs (HM61T/HM23 and S-34T/S-58) were isolated from soil and the faeces of Tibetan antelope (Pantholops hodgsonii) collected at the Qinghai-Tibet Plateau of PR China. All four new isolates were aerobic, non-motile, Gram-stain-positive, catalase-positive, oxidase-negative, and short rod-shaped bacteria. The results of phylogenetic analysis based on the full-length 16S rRNA genes and 283 core genomic genes indicated that the four strains were separated into two independent branches belonging to the genus Nocardioides. Strains HM61T and HM23 were most closely related to Nocardioides pelophilus THG T63T (98.58 and 98.65 % 16S rRNA gene sequence similarity). Strains S-34T and S-58 were most closely related to Nocardioides okcheonensis MMS20-HV4-12T (98.89 and 98.89 % 16S rRNA gene sequence similarity). The G+C contents of the genomic DNA of strains HM61T and S-34T were 70.6 and 72.5 mol%, respectively. Strains HM61T, S-34T and the type strains of closely related species in the analysis had average nucleotide identity values of 75.4-90.5 % as well as digital DNA-DNA hybridization values between 20.1 and 40.8 %, which clearly indicated that the four isolates represent two novel species within the genus Nocardioides. The chemotaxonomic characteristics of strains HM61T and S-34T were consistent with the genus Nocardioides. The major fatty acids of all four strains were iso-C16 : 0, C17 : 1 ω8c or C18 : 1 ω9c. For strains HM61T and S-34T, MK-8(H4) was the predominant respiratory quinone, ll-2,6-diaminopimelic acid was the diagnostic diamino acid in the cell-wall peptidoglycan, and the polar lipids profiles were composed of diphosphatidylglycerol and phosphatidylglycerol. Based on phylogenetic, phenotypic, and chemotaxonomic data, we propose that strains HM61T and S-34T represent two novel species of the genus Nocardioides, respectively, with the names Nocardioides bizhenqiangii sp. nov. and Nocardioides renjunii sp. nov. The type strains are HM61T (=GDMCC 4.343T=JCM 36399T) and S-34T (=CGMCC 4.7664T=JCM 33792T).

Nocardioides agri sp. nov., isolated from garden soil.

A novel bacterial strain, designated as MAH-18T, was isolated from soil sampled in a flower garden. Cells of strain MAH-18T were Gram-stain-positive, aerobic, motile, and rod-shaped. The colonies were beige in colour, smooth, and spherical when grown on Reasoner's 2A agar medium. Strain MAH-18T grew at 20-40 °C, pH 6.0-8.0, and 0-1.0 % NaCl. Cells were able to hydrolyse aesculin, gelatin, and Tween 20. According to the 16S rRNA gene sequence comparisons, the isolate was determined to be a member of the genus Nocardioides and most closely related to Nocardioides pyridinolyticus OS4T (97.9 %), Nocardioides hankookensis DS-30T (97.9 %), Nocardioides aquiterrae GW-9T (97.6 %), Nocardioides soli mbc-2T (97.5 %), Nocardioides conyzicola HWE 2-02T (97.4 %), and Nocardioides mangrovi GBK3QG-3T (96.3 %). Strain MAH-18T has a draft genome size of 4 788 325 bp (eight contigs), 4572 protein-coding genes, 46 tRNA, and three rRNA genes. The average nucleotide identity and digital DNA-DNA hybridization values between strain MAH-18T and the closest type strains were 81.5-83.4 % and 24.4-25.8 %, respectively. In silico genome mining revealed several biosynthetic gene clusters in the genome of the novel strain MAH-18T. The G+C content of the genomic DNA of strain was 72.2 mol% and the predominant isoprenoid quinone was MK-8 (H4). The main polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, and unknown phospholipids. The major cellular fatty acids were determined to be C16:0 iso and C17 : 1 ω6c. The DNA-DNA hybridization results and phenotypic, genotypic, and chemotaxonomic data demonstrated that strain MAH-18T represents a novel species, for which the name Nocardioides agri sp. nov. is proposed, with MAH-18T as the type strain (=KACC 19744T=CGMCC 1.13656T).

Nocardioides jiangxiensis sp. nov., a novel actinobacterium isolated from lakeside soil, exhibiting the biosynthesis potential of mycofactocin.

A Gram-stain-positive, rod-shaped, non-spore-forming and non-motile bacterium, designated WY-20T, was isolated from a lakeside soil sample collected in Jiangxi Province, PR China. Growth was observed at 20-42 °C (optimum 30 °C), pH 5.0-8.0 (optimum pH 7.0) and salinity of 0-3.0% (w/v; optimum 0.5%). Phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain WY-20T belongs to the genus Nocardioides and showed the highest sequence similarity (98.1%) to N. phosphati WYH11-7T, followed by N. cavernaquae K1W22B-1T (97.8%), N. marmoriterrae JOS5-1T (97.2%) and N. jensenii NBRC 14755T (97.1%). The average nucleotide identity and digital DNA-DNA hybridization values between strains WY-20T and N. phosphati WYH11-7T were 83.5% and 26.2%, respectively. The predominant fatty acids (≥ 10% of the total fatty acids) were C18:1ω9c, C17:0, C16:0, summed feature 8 (C18:1ω7c and/or C18: 1ω6c) and C17:1ω9c. The major menaquinone was MK-8 (H4). The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and two unidentified phospholipids. In addition, meso-diaminopimelic acid was the diagnostic diamino acid in the cell-wall peptidoglycan. Based on phenotypic, genotypic and phylogenetic pieces of evidence, strain WY-20T represents a novel species in the genus Nocardioides, for which the name Nocardioides jiangxiensis sp. nov. is proposed. The type strain is WY-20T (= GDMCC 4.317T = KACC 23379T).

Polyphasic characterization and genomic insights into Nocardioides turkmenicus sp. nov. isolated from a desert soil.

Strain KC13T, a novel desert-adapted, non-motile, Gram-stain-positive, rod-shaped, aerobic bacterium, was isolated from a soil sample collected from the Karakum Desert, Turkmenistan and characterised by a polyphasic approach. Phylogenetic analysis based on 16S rRNA sequences revealed that strain KC13T was a member of the genus Nocardioides, and formed a distinct cluster with Nocardioides luteus DSM 43366T (99.3% sequence identity), Nocardioides albus DSM 43109T (98.9%), Nocardioides panzhihuensis DSM 26487T (98.3%) and Nocardioides albertanoniae DSM 25218T (97.9%). The orthologous average nucleotide identity and digital DNA-DNA hybridization values were in the range of 85.8-91.0% and 30.2-35.9%, respectively, with the type strains of closely related species. The genome size of strain KC13T was 5.3 Mb with a DNA G + C content of 69.7%. Comprehensive genome analyses showed that strain KC13T, unlike its close relatives, had many genes associated with environmental adaptation. Strain KC13T was found to have chemotaxonomic and phenotypic characteristics of members of the genus Nocardioides and some differences from phylogenetic neighbours. Based on the chemotaxonomic, genomic, phenotypic and phylogenetic data, strain KC13T represents a novel species of the genus Nocardioides, for which the name Nocardioides turkmenicus sp. nov. is proposed, and the type strain is KC13T (= JCM 33525T = CGMCC 4.7619T).

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 pini sp. nov. and Nocardioides pinisoli sp. nov., two novel actinomycetes isolated from Pinus densiflora.

Two novel Gram-positive bacteria designated as strains STR2T and STR3T were isolated from the rhizosphere of a Pinus densiflora sample collected from Goyang-si, Republic of Korea. Strains STR2T and STR3T were aerobic, rod shaped, non-sporulated, catalase negative, oxidase negative and non-motile bacteria. They grew at 15-37 °C (optimum, 25-30 °C), at pH 6.0-11.0 (optimum, pH 7.0) and in the presence of 0-2% NaCl (optimum, 0 %, w/v). The chemotaxonomic and morphological characteristics of the novel strains were consistent with those of the members of Nocardioides. The phylogenetic analysis of the 16S rRNA gene sequences revealed that STR2T was closely related to N. cavernae YIM A1136T (99.3 %) and N. flavus Y4T (99.1 %), and STR3T was closely related to N. exalbidus DSM 22017T (99.0 %), N. baculatus G10T (98.8 %) and N. hwasunensis HFW-21T (98.7 %). The average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values of STR2T and STR3T with the most closely related strains that have publicly available whole genomes were 83.1-89.8 %, 80.9-89.6% and 26.2-39.1 %, respectively. The cell-wall peptidoglycan of strain STR2T and STR3T contained ll-diaminopimelic acid as the diagnostic amino acid. The major fatty acids in STR2T and STR3T were iso-C16 : 0 and C17 : 1 ω8c, and the predominant quinone was MK-8(H4). Their polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and other polar lipids. The draft genome sequences showed that the genomic DNA G+C content of STR2T and STR3T were both 72.2 mol%. Physiological and biochemical tests and 16S rRNA sequence analysis clearly revealed that STR2T and STR3T could represent novel Nocardioides species. Their proposed names were as follows: Nocardioides pini sp. nov. for strain STR2T (=KACC 22784T=TBRC 16336T) and Nocardioides pinisoli sp. nov. for strain STR3T (= KACC 22785T=TBRC 16337T).

Nocardioides okcheonensis sp. nov., isolated from riverside soil.

An actinobacterial strain designated MMS20-HV4-12T, displaying a high hydrolytic potential for various substrates, was isolated from a riverside soil sample and characterized by polyphasic taxonomic analysis. Growth occurred at 10-37 °C (optimum, 30°C), with NaCl concentrations of 0-4 % (optimum, 0 %) and at pH 7-9 (optimum, pH 8). MMS20-HV4-12T was catalase-positive, oxidase-negative, rod-shaped and formed creamy white-coloured colonies. Based on the results of 16S rRNA gene sequence analysis, MMS20-HV4-12T was found to be mostly related to the type strains of Nocardioides alpinus (98.3 % sequence similarity), Nocardioides furvisabuli (98.1 %) and Nocardioides zeicaulis (98.0 %). MMS20-HV4-12T showed optimal growth on Reaoner's 2A agar, forming white-coloured colonies. The diagnostic polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylinositol, the major fatty acids were iso-C16 : 0, C17 : 1 ω8c and 10-methyl-C17 : 0, the major isoprenoid quinone was MK-8(H4), the diagnostic cell-wall sugar was galactose, and the cell-wall diamino acid was ll-diaminopimelic acid. The genome of MMS20-HV4-12T was 4.47 Mbp in size with a G+C content of 72.9 mol%. The genome based analysis indicated low relatedness between MMS20-HV4-12T and all compared species of Nocardioides, as the highest digital DNA-DNA hybridization and the orthologous average nucleotide identity values were 26.8 and 83.8% respectively. Based on genotypic, phenotypic and phylogenomic characterization, MMS20-HV4-12T evidently represents a novel species of genus Nocardioides, for which the name Nocardioides okcheonensis sp. nov. (type strain=MMS20-HV4-12T=KCTC 49651T=LMG 32360T) is proposed.

Identification of Nocardioides marmotae sp. nov. and Nocardioides faecalis sp. nov., two new members of the genus Nocardioides.

A polyphasic taxonomic characterization of two novel strain pairs (designated zg-579T/zg-578 and zg-536T/zg-ZUI104) isolated from the faeces of Marmota himalayana was conducted based on phylogenetic analysis of the nearly full-length 16S rRNA gene and genome, digital DNA-DNA hybridization, ortho-average nucleotide identity (Ortho-ANI), and phenotypic and chemotaxonomic traits. Comparative analysis of the nearly full-length 16S rRNA gene sequences showed that strain zg-579T was most closely related to Nocardioides dokdonensis FR1436T (97.57 %) and Nocardioides deserti SC8A-24T (97.36 %), whereas strain zg-536T had the highest similarity to Nocardioides caeni MN8T (98.33 %), Nocardioides convexus W2-2-3T (98.26 %) and Nocardioides daeguensis 2C1-5T (98.19 %). Low levels of DNA-DNA relatedness and Ortho-ANI values (19.8-31.0 %/78.6-88.2 %, zg-579T; 19.9-31.3 %/78.8-86.2 %, zg-536T) between the two new type strains and previously known species within the genus Nocardioides support the hypothesis that the four newly characterized strains could be considered to represent two novel species within this genus. The dominant cellular fatty acids found in strain pair zg-536T/zg-ZUI104 were iso-C16 : 0 and C18 : 1 ω9c, whereas C17 : 1 ω8c was major component in zg-579T/zg-578. Galactose and ribose were the main cell-wall sugars in these two new strain pairs. Diphosphatidylglycerol (DPG), phosphatidylcholine, phosphatidylglycerol (PG) and phosphatidylinositol (PI) were the major polar lipids in zg-579T, whereas DPG, PG and PI predominated in zg-536T. Both strain pairs had MK8(H4) as the major respiratory quinone and ll-diaminopimelic acid as the major cell-wall peptidoglycan. The optimal growth conditions for the two novel strain pairs were 30 °C, pH 7.0 and 0.5 % NaCl (w/v). Based on these polyphasic characterizations, two novel species within the genus Nocardioides are proposed, i.e. Nocardioides marmotae sp. nov. and Nocardioides faecalis sp. nov., with zg-579T (=CGMCC 4.7663T=JCM 33892T) and zg-536T (=CGMCC 4.7662T=JCM 33891T) as the type strains.

Nocardioides cremeus sp. nov., Nocardioides abyssi sp. nov. and Nocardioides oceani sp. nov., three actinobacteria isolated from Western Pacific Ocean sediment.

Three Gram-stain-positive, non-motile, short rod-shaped, catalase-positive and oxidase-negative actinomycete strains (SOB44T, SOB72T and SOB77T) were isolated from a deep-sea sediment sample collected from the Western Pacific Ocean. Cells of the three strains showed optimum growth at 30 °C and pH 7.0. Strains SOB44T, SOB72T and SOB77T could tolerate up to 10, 9 and 9 % (w/v) NaCl concentration and grow at pH 5.0-12.0, 5.0-11.0 and 5.0-11.0, respectively. Phylogenetic results based on 16S rRNA gene sequences showed that the three isolates belonged to the genus Nocardioides and were identified as representing three novel species based on 78.0-93.1 % average nucleotide identity and 21.3-50.0 % DNA-DNA hybridization values with closely related reference strains. Strains SOB44T, SOB72T and SOB77T showed highest 16S rRNA gene sequence similarity to Nocardioides salarius CL-Z59T (99.2 %), Nocardioides deserti SC8A-24T (99.2 %) and Nocardioides marmotae zg-579T (98.5 %), respectively. All three strains had MK-8(H4) as the respiratory quinone, iso-C16 : 0 as the major fatty acid, and phosphatidylglycerol, diphosphatidylglycerol and phosphatidylinositol as the major polar lipids. The diagnostic diamino acid in the cell-wall peptidoglycan of all three isolates was ll-diaminopimelic acid. The DNA G+C contents of strains SOB44T, SOB72T and SOB77T were 71.1, 72.9 and 72.9 mol%, respectively. Based on the phenotypic, phylogenetic and genotypic data, strains SOB44T, SOB72T and SOB77T clearly represent three novel taxa within the genus Nocardioides, for which the names Nocardioides cremeus sp. nov. (type strain SOB44T=JCM 35774T= MCCC M28400T), Nocardioides abyssi sp. nov. (type strain SOB72T=JCM 35775T=MCCC M28318T) and Nocardioides oceani sp. nov. (type strain SOB77T=JCM 35776T=MCCC M28544T) are proposed.

Taxonomic Identification of the Arctic Strain Nocardioides Arcticus Sp. Nov. and Global Transcriptomic Analysis in Response to Hydrogen Peroxide Stress.

Microorganisms living in polar regions rely on specialized mechanisms to adapt to extreme environments. The study of their stress adaptation mechanisms is a hot topic in international microbiology research. In this study, a bacterial strain (Arc9.136) isolated from Arctic marine sediments was selected to implement polyphasic taxonomic identification based on factors such as genetic characteristics, physiological and biochemical properties, and chemical composition. The results showed that strain Arc9.136 is classified to the genus Nocardioides, for which the name Nocardioides arcticus sp. nov. is proposed. The ozone hole over the Arctic leads to increased ultraviolet (UV-B) radiation, and low temperatures lead to increased dissolved content in seawater. These extreme environmental conditions result in oxidative stress, inducing a strong response in microorganisms. Based on the functional classification of significantly differentially expressed genes under 1 mM H2O2 stress, we suspect that Arc9.136 may respond to oxidative stress through the following strategies: (1) efficient utilization of various carbon sources to improve carbohydrate transport and metabolism; (2) altering ion transport and metabolism by decreasing the uptake of divalent iron (to avoid the Fenton reaction) and increasing the utilization of trivalent iron (to maintain intracellular iron homeostasis); (3) increasing the level of cell replication, DNA repair, and defense functions, repairing DNA damage caused by H2O2; (4) and changing the composition of lipids in the cell membrane and reducing the sensitivity of lipid peroxidation. This study provides insights into the stress resistance mechanisms of microorganisms in extreme environments and highlights the potential for developing low-temperature active microbial resources.

Nocardioides: "Specialists" for Hard-to-Degrade Pollutants in the Environment.

Nocardioides, a genus belonging to Actinomycetes, can endure various low-nutrient conditions. It can degrade pollutants using multiple organic materials such as carbon and nitrogen sources. The characteristics and applications of Nocardioides are described in detail in this review, with emphasis on the degradation of several hard-to-degrade pollutants by using Nocardioides, including aromatic compounds, hydrocarbons, haloalkanes, nitrogen heterocycles, and polymeric polyesters. Nocardioides has unique advantages when it comes to hard-to-degrade pollutants. Compared to other strains, Nocardioides has a significantly higher degradation rate and requires less time to break down substances. This review can be a theoretical basis for developing Nocardioides as a microbial agent with significant commercial and application potential.

Nocardioides panacis sp. nov., isolated from soil of a ginseng field.

A bacterial strain designated as G188T was isolated from ginseng field soil in the Republic of Korea. Phylogenetic analysis of 16S rRNA gene sequences showed that strain G188T formed a distinct lineage within the genus Nocardioides, family Nocardioidaceae, order Propionibacteriales. Sequence similarity revealed that strain G188T was most closely related to Nocardioides iriomotensis IR27-S3T (97.7 % 16S rRNA similarity). The genome size of strain G188T was 4 901 775 bp, and the genomic DNA G+C content was 72.3 mol%. The average nucleotide identity and DNA-DNA hybridization values with other Nocardioides species were less than 75.6 and 20.1 %, respectively. The main fatty acids of strain G188T were C17 : 0, C17 : 1 ω8c and iso-C16 : 0. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylinositol, and the major respiratory quinone was menaquinone 8, supporting that strain G188T was affiliated with the genus Nocardioides. Based on biochemical, chemotaxonomic and phylogenetic analyses, the novel species Nocardioides panacis G188T (KACC 21695T=LMG 31733T) is proposed.

Nocardioides ochotonae sp. nov., Nocardioides campestrisoli sp. nov. and Nocardioides pantholopis sp. nov., isolated from the Qinghai-Tibet Plateau.

Six Gram-stain-positive, aerobic and irregular-rod-shaped actinobacteria (ZJ1313T, ZJ1307, MC1495T, Y192, 603T and X2025) were isolated from the Qinghai-Tibet Plateau of China and were characterized using a polyphasic taxonomic method. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the six new strains formed three distinct clusters within the genus Nocardioides, and strains ZJ1313T and ZJ1307 were most closely related to N. solisilvae JCM 31492T (16S rRNA gene sequence similarity, 98.0 %), MC1495T and Y192 to N. houyundeii 78T (98.5 %), and 603T and X2025 to N. dokdonensis JCM 14815T (97.6 %). The digital DNA-DNA hybridization values of strains ZJ1313T, MC1495T and 603T among each other and with type strains of their closest relatives were all below the 70 % cut-off point, but values within each pair of new strains were all higher than the threshold. The major fatty acids of these strains were iso-C16 : 0, C17 : 1 ω8c or C18 : 1 ω9c. MK-8(H4) was the predominant respiratory menaquinone and ʟʟ-2,6-diaminopimelic acid was the diagnostic diamino acid. All the strains shared diphosphatidylglycerol (predominant), phosphatidylglycerol, phosphatidylcholine and phosphatidylinositol as the common polar lipids, with minor difference in the types of unidentified phospholipids, glycolipids and lipids. The G+C contents based on genomic DNA of strains ZJ1313T, MC1495T and 603T were 72.5, 72.1 and 73.2 mol%, respectively. The above results suggested that strain pairs ZJ1313T/ZJ1307, MC1495T/Y192 and 603T/X2025 represent three new species of genus Nocardioides, for which the names Nocardioides ochotonae sp. nov. (ZJ1313T=GDMCC 4.177T=KCTC 49537T=JCM 34185T), Nocardioides campestrisoli sp. nov. (MC1495T=GDMCC 4.176T=KCTC 49536T=JCM 34307T) and Nocardioides pantholopis sp. nov. (603T=CGMCC 4.7510T=DSM 106494T) are proposed accordingly.

Nocardioides palaemonis sp. nov. and Tessaracoccus palaemonis sp. nov., isolated from the gastrointestinal tract of lake prawn.

Two novel Gram-stain-positive, non-motile and non-spore-forming bacterial strains, designated J2M5T and J1M15T, were isolated from the gastrointestinal tract of a lake prawn Palaemon paucidens. Strain J2M5T was an obligately aerobic bacterium that formed milky-coloured colonies and showed a rod-coccus cell cycle, while strain J1M15T was a facultatively aerobic bacterium that formed orangish-yellow-coloured colonies and showed rod-shaped cells. Strains J2M5T and J1M15T showed the highest 16S rRNA gene sequence similarity to Nocardioides ganghwensis JC2055T (98.63 %) and Tessaracoccus flavescens SST-39T (98.08 %), respectively. The whole-genome sequence of strain J2M5T was 4.52 Mbp in size and the genomic G+C content directly calculated from the genome sequence of strain J2M5T was 72.5 mol%. The whole-genome sequence of strain J1M15T was 3.20 Mbp in size and the genomic G+C content directly calculated from the genome sequence of strain J1M15T was 69.6mol %. Strains J2M5T and J1M15T showed high OrthoANI similarity to N. ganghwensis JC2055T (83.6 %) and T. flavescens (77.2 %), respectively. We analysed the genome sequences of strains J2M5T and J1M15T in terms of carbohydrate-active enzymes, antibiotic resistance genes and virulence factor genes. Strains J2M5T and J1M15T contained MK-8 (H4) and MK-9 (H4) as the predominant respiratory quinones, respectively. The major polar lipids of both strains were phosphatidylglycerol and diphosphatidylglycerol. Additionally, strain J2M5T possessed phosphatidylcholine, phosphatidylserine and phosphatidylethanolamine. The cellular sugar components of strain J2M5T were ribose, mannose, glucose and galactose, and its cellular amino acid components were l-alanine and l-lysine. The cellular sugar components of strain J1M15T were rhamnose, ribose, mannose and glucose, and its cellular amino acid component was l-alanine. The major cellular fatty acids of strains J2M5T and J1M15T were iso-C16 : 0 and anteiso-C15 : 0, respectively. The multiple taxonomic analyses indicated that strains J2M5T and J1M15T represent novel species of the genus Nocardioides and Tessaracoccus, respectively. We propose the names Nocardioides palaemonis sp. nov. and Tessaracoccus palaemonis sp. nov. for strain J2M5T (=KCTC 49461T=CCUG 74767T) and strain J1M15T (=KCTC 49462T=CCUG 74766T), respectively.

Nocardioides alcanivorans sp. nov., a novel hexadecane-degrading species isolated from plastic waste.

Strain NGK65T, a novel hexadecane degrading, non-motile, Gram-positive, rod-to-coccus shaped, aerobic bacterium, was isolated from plastic polluted soil sampled at a landfill. Strain NGK65T hydrolysed casein, gelatin, urea and was catalase-positive. It optimally grew at 28 °C, in 0-1% NaCl and at pH 7.5-8.0. Glycerol, d-glucose, arbutin, aesculin, salicin, potassium 5-ketogluconate, sucrose, acetate, pyruvate and hexadecane were used as sole carbon sources. The predominant membrane fatty acids were iso-C16:0 followed by iso-C17:0 and C18:1 ω9c. The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and hydroxyphosphatidylinositol. The cell-wall peptidoglycan type was A3γ, with ll-diaminopimelic acid and glycine as the diagnostic amino acids. MK 8 (H4) was the predominant menaquinone. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NGK65T belongs to the genus Nocardioides (phylum Actinobacteria), appearing most closely related to Nocardioides daejeonensis MJ31T (98.6%) and Nocardioides dubius KSL-104T (98.3%). The genomic DNA G+C content of strain NGK65T was 68.2%. Strain NGK65T and the type strains of species involved in the analysis had average nucleotide identity values of 78.3-71.9% as well as digital DNA-DNA hybridization values between 22.5 and 19.7%, which clearly indicated that the isolate represents a novel species within the genus Nocardioides. Based on phenotypic and molecular characterization, strain NGK65T can clearly be differentiated from its phylogenetic neighbours to establish a novel species, for which the name Nocardioides alcanivorans sp. nov. is proposed. The type strain is NGK65T (=DSM 113112T=NCCB 100846T).

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 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).

Nocardioides mangrovi sp. nov., a novel endophytic actinobacterium isolated from root of Kandelia candel.

A novel species of endophytic actinobacterium, designated strain GBK3QG-3T, was isolated from surface-sterilized root of Kandelia candel collected from Beilun Estuary, Guangxi Zhuang Autonomous Region, PR China. Cells of strain GBK3QG-3T were Gram-stain-positive, aerobic, non-spore-forming and rod-shaped. Growth of GBK3QG-3T was observed at 10-40 °C (optimum, 30 °C), pH 5.0-9.0 (optimum, pH 7.0) and in the presence of 0-3 % (w/v) NaCl (optimum, 0 %). The G+C content of genomic DNA was determined to be 72.2 mol%. On the basis of 16S rRNA gene sequence analysis, strain GBK3QG-3T was most related to the type strain of Nocardioides agrisoli CCTCC AB 2017058T (97.7 % 16S rRNA gene sequence similarity), followed by Nocardioides ginkgobilobae SYP-A7303T (97.0 %) and Nocardioides aquiterrae GW-9T (96.9 %). Average nucleotide identity and digital DNA-DNA hybridization values between strain GBK3QG-3T and some strains of the genus Nocardioides with publicly available genomes were below 84.3 and 30.0 %, respectively. The cell-wall peptidoglycan contained ll-diaminopimelic acid. The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, an unknown phospholipid and an unknown lipid. The major menaquinone was identified as MK-8(H4), and the major fatty acids were identified as iso-C16 : 0, iso-C17 : 0 and anteiso-C17 : 0. Based on evidence collected from the phenotypic, genotypic and phylogenetic analyses, we propose a novel species named Nocardioides mangrovi sp. nov. The type strain is GBK3QG-3T (=CGMCC 4.7708T=JCM 34553T).

Nocardioides humilatus sp. nov., isolated from farmland soil in the Republic of Korea.

A Gram-stain positive, aerobic, irregularly rod-shaped, non-spore-forming bacterium, designated as BN130099T, was isolated from farmland soil sampled in Goesan-gun, Chungbuk, Republic of Korea. Phylogenetic analysis of its 16S rRNA gene sequence showed that the strain is closely related to Nocardioides pelophilus KACC 19192T with 98.11 % similarity. The DNA G+C content of strain BN130099T was 68.84 mol% (draft genome sequence). The genome sequence of BN130099T displayed key enzymes involved in bioremediation of organic pollutants and biosynthetic clusters of saquayamycin. The strain contained ll-2,6-diaminopimelic acid in the cell-wall peptidoglycan and MK-8(H4) as the major respiratory quinone. The predominant fatty acid was iso-C16 : 0. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine and phosphatidylinositol. The results of physiological and biochemical characterization allowed the phenotypic differentiation of strain BN130099T from N. pelophilus KACC 19192T. The strain represents a novel species of the genus Nocardioides, for which we propose the name Nocardioides humilatus sp. nov. The type strain is BN130099T (=KCTC 49079T=CCTCC AB 2018135T).

Nocardioides lacusdianchii sp. nov., an attached bacterium of Microcystis aeruginosa.

Attached bacteria of Microcystis play important roles in the occurence, outbreak and decline of Microcystis water blooms. In this study, a novel actinobacterium, designated strain JXJ CY 38 T, was isolated from the culture mass of Microcystis aeruginosa FACHB-905 (MAF), collected from Lake Dianchi, south-west, China. The strain was found to be a Gram-stain positive, short rod, catalase positive and oxidase negative. The isolate was found to be able to grow at 5.0-38.0 °C (optimum, 28.0 °C), pH 4.0-11.0 (optimum, 7.0-8.0) and 0-3.0% (w/v, optimum, 0%) NaCl. Based on 16S rRNA gene sequences, strain JXJ CY 38 T shows high similarities to Nocardioides furvisabuli JCM 13813 T (99.0%) and Nocardioides alpinus JCM 18960 T (98.7%), and less than 98.2% similarities to other members of the genus. The major cellular fatty acids (> 10.0%) were identified as iso-C16:0 (23.6%), C18:1ω9c (18.2%) and C17:1ω8c (16.4%), while the predominant menaquinone was found to be MK-8 (H4). The diagnostic diamino acids in the cell wall peptidoglycan were identified as aspartic acid, glutamic acid, glycine and alanine, with mannose, ribose and arabinose as whole cell sugars. The polar lipids were found to be diphosphatidylglycerol, phosphatidylglycerol, a phospholipid, phosphatidylcholine and an unidentified lipid. The DNA G + C content was determined to be 71.3%. The digital DNA-DNA hybridization and average nucleotide identity values between strain JXJ CY 38 T and the type strains N. furvisabuli JCM 13813 T and N. alpinus JCM 18960 T were 49.4% and 37.7%, and 92.0% and 83.4%, respectively. On the basis of the above taxonomic data and differences in physiological characteristics from the closely related type strains, strain JXJ CY 38 T was determined to represent a novel species of genus Nocardioides, for which the name Nocardioides lacusdianchii sp. nov. is proposed. The type strain is JXJ CY 38 T (= KCTC 49381 T = CGMCC 4.7665 T). Strain JXJ CY 38 T apparently exhibits complex effects on the interactions between MAF and other attached bacteria, including the promotion or inhibition of the growth of MAF and bacteria, and the synthesis and release of microcystins by MAF.