Genus Nocardioides Research Articles

Nocardioides soli sp. nov., a bacterium isolated from a mountain soil.

Strain SR-1(T), a Gram-positive, strictly-aerobic, short-rod shaped, non-motile bacterium, was isolated from a mountain soil collected in Seoul Women's University in South Korea. Growth occurred between 15 and 37°C (optimum, 30°C), at pH 6.0-9.0 (optimum, pH 7.0) and with 0-2% NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SR-1(T) belongs to the genus Nocardioides and is closely related to Nocardioides simplex KCTC 9106(T) (96.8%), Nocardioides caeni MN8(T) (96.7%), Nocardioides aromaticivorans H-1(T) (96.6%), and Nocardioides kongijuensis A2-4(T) (96.6%). Chemotaxonomic data revealed that strain SR-1(T) possesses MK-8(H4) as predominant menaquinone, LL-2,6-diaminopimelic acid as the diagnostic diamino acid, phosphatidylglycerol and diphosphatidylglycerol as predominant polar lipids and iso-C16:0, 10-methyl-C18:0, and C18:1 ω9c are major fatty acids. The DNA G+C content of the strain SR-1(T) was 72.4mol%. Based on polyphasic evidence, strain SR-1(T) (=KEMC 9004-134(T)=JCM 19684(T)) should be classified as the type strain of a novel Nocardioides species, for which the name Nocardioides soli sp. nov. is proposed.

Nocardioides rubroscoriae sp. nov., isolated from volcanic ash

A rod-shaped actinobacterium, designated Sco-A25(T), was isolated from a red-coloured layer of scoria (volcanic ash) in the Republic of Korea and subjected to a polyphasic taxonomic characterization. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain Sco-A25(T) is a member of the genus Nocardioides and formed a tight monophyletic unit with the type strain of Nocardioides plantarum (98.7% gene similarity). LL-Diaminopimelic acid was detected in the cell wall. The predominant menaquinone is MK-8(H4). The polar lipids found were phosphatidylinositol, diphosphatidylglycerol, phosphatidylglycerol, and an unknown phospholipid. The fatty acid profile was represented by large amounts of saturated, unsaturated and iso-branched fatty acids. The DNA G+C content was 71.6mol%. Genomic DNA similarity between strain Sco-A25(T) and N. plantarum KCTC 9577(T) was 47.8%. On the basis of the results of phenotypic, genetic and phylogenetic analyses presented here, strain Sco-A25(T) is considered to represent a novel species of the genus Nocardioides, for which the name Nocardioides rubroscoriae sp. nov. is proposed. The type strain is Sco-A25(T) (=KCTC 19805(T)=DSM 23986(T)=NBRC 107916(T)).

Metabolism of Atrazine in Liquid Cultures and Soil Microcosms by Nocardioides Strains Isolated from a Contaminated Nigerian Agricultural Soil

Atrazine-degrading microorganisms designated EAA-3 and EAA-4, belonging to the genus Nocardioides, were obtained from an agricultural soil in Nigeria. The degradation kinetics of the two strains revealed total disappearance of 25 mg l−1 of atrazine in less than 72 h of incubation at the rate of 0.42 mg l−1 h−1 and 0.35 mg l−1 h−1, respectively. Screening for atrazine catabolic genes in these organisms revealed the presence of trzN, atzB, and atzC. Other genes, specifically atzA, atzD, and trzD, were not detected. Potential intermediates of atrazine catabolic route such as hydroxyatrazine, desethylatrazine, and desisopropylatrazine were utilized as sources of carbon and energy, while desisopropyl desethyl-2-hydroxyatrazine and desisopropyl-2-hydroxyatrazine were attacked but in the presence of glucose. A soil microcosm study showed that degradation was faster in microcosms contaminated with 13 mg of atrazine per g−1 of soil compared with 480 mg g−1 of soil. In the former, degradation was 10% higher in the inoculated soil than the non-inoculated control (natural attenuation) over the 28-day study period. Corresponding value obtained for the latter was nearly 70% higher. This study has demonstrated that the bacterial strains isolated enhanced atrazine degradation and the catabolic activities of these strains were not affected with increasing soil atrazine concentration.

Nocardioides panaciterrulae sp. nov., isolated from soil of a ginseng field, with ginsenoside converting activity

A Gram-positive, coccoid to rod-shaped, non-spore-forming bacterium, designated Gsoil 958(T), was isolated from soil of a ginseng field located in Pocheon province in South Korea. This bacterium was characterized in order to determine its taxonomic position by using a polyphasic approach. Strain Gsoil 958(T) was observed to grow well at 25-30 °C and at pH 7.0 on R2A and nutrient agar without NaCl supplementation. Strain Gsoil 958(T) was determined to have β-glucosidase activity and the ability to transform ginsenoside Rb1 (one of the dominant active components of ginseng) to F2 via gypenoside XVII and Rd. On the basis of 16S rRNA gene sequence similarity, strain Gsoil 958(T) was shown to belong to the family Nocardioidaceae and related most closely to Nocardioides koreensis MSL-09(T) (97.6 % 16S rRNA gene sequence similarity), Nocardioides aquiterrae GW-9(T) (97.0 %), and Nocardioides sediminis MSL-01(T) (97.0 %). The sequence similarities with other validly named species within the genus Nocardioides were less than 96.8 %. Strain Gsoil 958(T) was characterized chemotaxonomically as having LL-2,6-diaminopimelic acid in the cell-wall peptidoglycan, MK-8(H4) as the predominant menaquinone, and iso-C16:0, iso-C16:1 H, iso-C14:0, iso-C15:0 were identified as the major fatty acids. The G + C content of genomic DNA was determined to be 70.8 mol %. The chemotaxonomic properties and phenotypic characteristics supported the affiliation of strain Gsoil 958(T) to the genus Nocardioides. The results of both physiological and biochemical tests allowed for differentiation of strain Gsoil 958(T) from the recognized Nocardioides species. Therefore, strain Gsoil 958(T) is considered to represent a novel species of the genus Nocardioides, for which the name Nocardioides panaciterrulae sp. nov. is proposed, with the type strain Gsoil 958(T) (KACC 14271(T) = KCTC 19471(T) = DSM 21350(T)).

Nocardioides panzhihuaensis sp. nov., a novel endophytic actinomycete isolated from medicinal plant Jatropha curcas L.

A novel Gram-positive, aerobic, rod-shaped and mycelia-producing bacterial strain, designated KLBMP 1050(T), was isolated from the stem of the oil-seed plant Jatropha curcas L. collected from Sichuan Province, south-west China. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the isolate KLBMP 1050(T) belonged to the genus Nocardioides, with the highest sequence similarity to Nocardioides albus KCTC 9186(T) (99.38 %) and Nocardioides luteus KCTC 9575(T) (99.03 %). However, the DNA-DNA relatedness of isolate KLBMP 1050(T) to these two type strains were 37.5 ± 3.5 and 33 ± 2.3 %, respectively. Strain KLBMP 1050(T) grew at the pH range 6-11, temperature range 10-32 °C and with 0-12 % NaCl. The physiological properties of strain KLBMP 1050(T) differ from those of N. albus KCTC 9186(T) and N. luteus KCTC 9575(T). The cell-wall peptidoglycan contained LL: -diaminopimelic acid and MK-8(H(4)) was the major respiratory quinone. The predominant cellular fatty acid of strain KLBMP 1050(T) was iso-C(16:0) (23.3 %). The total DNA G+C content was 70.1 mol%. On the basis of the phenotypic, chemotaxonomic and phylogenetic data, strain KLBMP 1050(T) represents a novel species of the genus Nocardioides, for which the name Nocardioides panzhihuaensis sp. nov. is proposed. The type strain is KLBMP 1050(T) (= KCTC 19888(T) = NBRC 108680(T)).

Thirteen novel deoxynivalenol-degrading bacteria are classified within two genera with distinct degradation mechanisms

The mycotoxin deoxynivalenol (DON), a secondary metabolite produced by species of the plant pathogen Fusarium, causes serious problems in cereal crop production because of its toxicity towards humans and livestock. A biological approach for the degradation of DON using a DON-degrading bacterium (DDB) appears to be promising, although information about DDBs is limited. We isolated 13 aerobic DDBs from a variety of environmental samples, including field soils and wheat leaves. Of these 13 strains, nine belonged to the Gram-positive genus Nocardioides and other four to the Gram-negative genus Devosia. The degradation phenotypes of the two Gram types were clearly different; all washed cells of the 13 strains degraded 100 μg mL(-1) DON to below the detection limit (0.5 μg mL(-1)), but the conditions inducing the DON-degrading activities differed between the two Gram types. The HPLC profiles of the DON metabolites were also distinct between the two genera, although all strains produced 3-epi-deoxynivalenol. The Gram-positive strains showed DON assimilation in media containing DON as a carbon source, whereas the Gram-negatives did not. Our results suggest that aerobic DDBs are distributed within at least two phylogenetically restricted genera, suggesting independent evolution of the DON-degradation mechanisms.

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

A Gram-reaction-positive, rod-shaped, non-motile, non-spore-forming bacterium (strain BX5-10(T)) was isolated from the soil of a ginseng field on Baekdu Mountain in Jilin district, China. The taxonomic position of this bacterium was determined in an investigation based on a polyphasic approach. On the basis of 16S rRNA gene sequence analysis, strain BX5-10(T) was shown to belong to the family Nocardioidaceae and to be most closely related to Nocardioides plantarum NCIMB 12834(T) (96.5% sequence similarity), Nocardioides dokdonensis KCTC 19309(T) (96.2%) and Nocardioides fonticola NAA-13(T) (95.1%). Strain BX5-10(T) was characterized chemotaxonomically as having ll-2,6-diaminopimelic acid in its cell-wall peptidoglycan, MK-8(H(4)) as the predominant menaquinone and C(18:1)ω9c, C(16:0) and C(17:1)ω8c as its major fatty acids. The G+C content of the genomic DNA was 70.3 mol%. The novel strain could be differentiated genotypically and phenotypically from all recognized species of the genus Nocardioides. Based on the results of the phylogenetic analyses and the genotypic and phenotypic data, a novel species, Nocardioides ginsengagri sp. nov., is proposed. The type strain is BX5-10(T) (=KCTC 19467(T)=DSM 21362(T)).

Nocardioides alpinus sp. nov., a psychrophilic actinomycete isolated from alpine glacier cryoconite

A gram-positive, non-motile, rod-shaped, psychrophilic actinomycete, designated strain Cr7-14(T), was isolated from alpine glacier cryoconite. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain Cr7-14(T) was related to members of the genus Nocardioides and shared highest 16S rRNA gene sequence similarities with the type strains of Nocardioides furvisabuli (98.6 %), Nocardioides ganghwensis (98.2 %), Nocardioides oleivorans (98.1 %) and Nocardioides exalbidus (97.6 %). The predominant cellular fatty acids of strain Cr7-14(T) were C(17 : 1)ω8c (39.5 %) and iso-C(16 : 0) (32.4 %). The major menaquinone was MK-8(H(4)). The diagnostic diamino acid in the cell-wall peptidoglycan was ll-2,6-diaminopimelic acid. The predominant cell-wall sugars were galactose and rhamnose. The polar lipid pattern contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylinositol, four unknown glycolipids and two unknown polar lipids. The genomic DNA G+C content was 71.9 mol%. On the basis of phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness data, a novel species, Nocardioides alpinus sp. nov., is proposed, with Cr7-14(T) ( = DSM 23325(T) = LMG 26053(T) = CGMCC 1.10697(T)) as the type strain.

Nocardioides iriomotensis sp. nov., an actinobacterium isolated from forest soil

An actinomycete strain, designated IR27-S3(T), was isolated from a forest soil sample collected from Iriomote Island, Okinawa, Japan. Cells of the isolate were Gram-stain-positive, aerobic, non-sporulating, non-motile coccoids or short rods. The strain grew in the presence of 0-7 % (w/v) NaCl, at pH 6-8 and at 12-37 °C, with optimum growth at 30 °C. Chemotaxonomically, the strain contained LL-diaminopimelic acid as the diagnostic diamino acid and MK-8(H₄) as the predominant menaquinone. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and an unknown phospholipid. The major cellular fatty acids were iso-C₁₆:₀, C₁₇:₁ cis-9, C₁₅:₀ and iso-C₁₅:₀. The DNA G+C content was 73.7 mol%. On the basis of 16S rRNA gene sequence analysis, strain IR27-S3(T) was closely related to Nocardioides mesophilus MSL-22(T) (98.1 % 16S rRNA gene sequence similarity), Marmoricola bigeumensis MSL-05(T) (97.2 %) and Nocardioides jensenii DSM 20641(T) (96.5 %). On the basis of fatty acid analysis, phylogenetic analysis and phenotypic data, the isolate should be classified in a novel species of the genus Nocardioides, for which the name Nocardioides iriomotensis sp. nov. is proposed. The type strain is IR27-S3(T) ( = NBRC 105384(T) = KACC 14926(T)).

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

A Gram-positive, rod-shaped, non-spore-forming bacterium (Gsoil 485(T)) was isolated from the soil of a ginseng field located in Pocheon province in South Korea. This bacterium was characterized in order to determine its taxonomic position by using the polyphasic approach. On the basis of 16S rRNA gene sequence similarity, strain Gsoil 485(T) was shown to belong to the family Nocardioidaceae and related to Nocardioides koreensis (96.8% 16S rRNA gene sequence similarity), Nocardioides basaltis (96.7%), Nocardioides salarius (96.7%), and Nocardioides sediminis (96.5%). The sequence similarity with other species that had validly published names within the genus Nocardioides was less than 96.4%. Strain Gsoil 485(T) was characterized chemotaxonomically as having LL-2,6-diaminopimelic acid in a cell-wall peptidoglycan, MK-8(H(4)) as the predominant menaquinone, and iso-C(16:0), C(18:1) ω9c as the major fatty acids. The G+C content of genomic DNA was 71.6 mol%. The chemotaxonomic properties and phenotypic characteristics supported the affiliation of strain Gsoil 485(T) to the genus Nocardioides. The results of both physiological and biochemical tests allowed for genotypic differentiation of strain Gsoil 485(T) from the recognized Nocardioides species. Therefore, strain Gsoil 485(T) is considered to represent the novel species, for which the name Nocardioides ginsengisegetis sp. nov. is proposed, with the type strain Gsoil 485(T) (KACC 14269(T) =KCTC 19469(T) =DSM 21349(T)).

Nocardioides sp. strain WSN05-2, isolated from a wheat field, degrades deoxynivalenol, producing the novel intermediate 3-epi-deoxynivalenol

The mycotoxin deoxynivalenol (DON) causes serious problems worldwide in the production of crops such as wheat and barley because of its toxicity toward humans and livestock. A bacterial culture capable of degrading DON was obtained from soil samples collected in wheat fields using an enrichment culture procedure. The isolated bacterium, designated strain WSN05-2, completely removed 1,000 μg/mL of DON from the culture medium after incubation for 10 days. On the basis of phylogenetic studies, WSN05-2 was classified as a bacterium belonging to the genus Nocardioides. WSN05-2 showed significant growth in culture medium with DON as the sole carbon source. High-performance liquid chromatography analysis indicated the presence of a major initial metabolite of DON in the culture supernatant. The metabolite was identified as 3-epi-deoxynivalenol (3-epi-DON) by mass spectrometry and 1H and 13C nuclear magnetic resonance analysis. The amount of DON on wheat grain was reduced by about 90% at 7 days after inoculation with WSN05-2. This is the first report of a Nocardioides sp. strain able to degrade DON and of the yet unknown 3-epi-DON as an intermediate in the degradation of DON by a microorganism.

Nocardioides ultimimeridianus sp. nov. and Nocardioides maradonensis sp. nov., isolated from rhizosphere soil

Two novel Gram-reaction-positive, rod-shaped actinobacterial strains, designated RP-B26(T) and RP-B30(T), were isolated from rhizosphere soil of a cliff-associated plant (Peucedanum japonicum Thunb.) which was collected from Mara Island, Republic of Korea. The colonies of the isolates were circular, smooth, convex and moderately yellow-light-yellow in colour. 16S rRNA gene sequence analysis revealed that the isolates belonged to the family Nocardioidaceae and formed two distinct sublineages within the radiation of the genus Nocardioides. 16S rRNA gene sequence similarity between the isolates was 98.2 %. The closest phylogenetic neighbours of strain RP-B26(T) were Nocardioides humi DCY24(T) and Nocardioides kongjuensis A2-4(T) with 97.4 and 97.0 % 16S rRNA gene sequence similarity, respectively, whereas 16S rRNA gene sequence similarities between strain RP-B30(T) and N. humi DCY24(T) and N. kongjuensis A2-4(T) were 96.5 and 96.0 %, respectively. Both of the isolates contained ll-diaminopimelic acid as the diagnostic diamino acid in the cell walls. The predominant menaquinone was MK-8(H(4)). The polar lipids were phosphatidylinositol and phosphatidylglycerol. The fatty acid profiles of the isolates were characterized by the presence of saturated, unsaturated, 10-methyl and hydroxyl fatty acids, with small amounts of branched fatty acids. The DNA G+C contents of strains RP-B26(T) and RP-B30(T) were 73.0 and 71.7 mol%, respectively. Levels of DNA-DNA relatedness between the isolates were 44.9 ± 1.5 % (thermal renaturation method) and 43.2 % (photobiotin-labelled method); the isolates showed low DNA-DNA relatedness values (<11 %) to the most closely related strain, N. humi KCTC 19265(T). On the basis of the phenotypic, genotypic and DNA-DNA hybridization data presented here, the isolates are considered to represent two novel species of the genus Nocardioides, for which the names Nocardioides ultimimeridianus sp. nov. (type strain RP-B26(T) = KCTC 19368(T) = DSM 19768(T)) and Nocardioides maradonensis sp. nov. (type strain RP-B30(T) = KCTC 19384(T) = DSM 19769(T)) are proposed.

Prevalence of the gene trzN and biogeographic patterns among atrazine-degrading bacteria isolated from 13 Colombian agricultural soils

The following study evaluated the diversity and biogeography of 83 new atrazine-degrading bacteria and the composition of their atrazine degradation genes. These strains were isolated from 13 agricultural soils and grouped according to rep-PCR genomic fingerprinting into 11 major clusters, which showed biogeographic patterns. Three clusters (54 strains) belonged to the genus Arthrobacter, seven clusters (28 strains) were similar to the genus Nocardioides and only one strain was a gram-negative from the genus Ancylobacter. PCR assays for the detection of the genes atzA, B, C, D, E, F and trzN conducted with each of the 83 strains revealed that 82 strains (all gram positive) possessed trzN, 74 of them possessed the combination of trzN, atzB and atzC, while only the gram-negative strain had atzA. A similar PCR assay for the two analogous genes, atzA and trzN, responsible for the first step of atrazine degradation, was performed with DNA extracted directly from the enrichment cultures and microcosms spiked with atrazine. In these assays, the gene trzN was detected in each culture, while atzA was detected in only six out of 13 soils. These results raise an interesting hypothesis on the evolutionary ecology of the two atrazine chlorohydrolase genes (i.e. atzA and trzN) and about the biogeography of atrazine-degrading bacteria.

Nocardioides hungaricus sp. nov., isolated from a drinking water supply system

Three Gram-positive, rod-shaped bacterial strains were isolated from the drinking water supply system of the Hungarian capital, Budapest. Phylogenetic analysis on the basis of 16S rRNA gene sequence comparison revealed that the isolates represented a distinct cluster within the clade of the genus Nocardioides and were most closely related to Nocardioides pyridinolyticus OS4(T), Nocardioides aquiterrae GW-9(T), Nocardioides sediminis MSL-01(T) and N. hankookensis DS-30(T). The peptidoglycan based on LL-2,6-diaminopimelic acid, the major menaquinone MK-8(H₄), the cellular fatty acid profile with iso-C₁₆:₀ and anteiso-C₁₇:₀ as predominating components and the DNA G+C content of 71.4 mol% (strain 1RaM5-12(T)) were consistent with the affiliation of the isolates to the genus Nocardioides. Because of differences in physiological characteristics, matrix-assisted laser-desorption/ionization time-of-flight mass spectra of protein extracts, PvuII RiboPrinter patterns and 96.1 % 16S rRNA gene sequence similarity between strain 1RaM5-12(T) and its closest phylogenetic neighbour, N. pyridinolyticus OS4(T), a novel species, Nocardioides hungaricus sp. nov., is proposed. The type strain is 1RaM5-12(T) (=DSM 21673(T) =NCAIM 02330(T)).

Nocardioides caricicola sp. nov., an endophytic bacterium isolated from a halophyte, Carex scabrifolia Steud.

A Gram-staining-positive, coccoid to rod-shaped bacterium, designated strain YC6903(T), was isolated from a halophytic plant (Carex scabrifolia Steud.) collected from sand dunes at Namhae Island, Korea, and its taxonomic position was investigated by using a polyphasic approach. Strain YC6903(T) grew optimally at 30 °C and at pH 8.0. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain YC6903(T) belongs to the genus Nocardioides in the family Nocardioidaceae. Strain YC6903(T) was related most closely to Nocardioides pyridinolyticus OS4(T) (97.0 % 16S rRNA gene sequence similarity), Nocardioides dokdonensis FR1436(T) (96.6 %), Nocardioides aquiterrae GW-9(T) (96.6 %) and Nocardioides hankookensis DS-30(T) (96.6 %). The cell-wall peptidoglycan contained LL-diaminopimelic acid and MK-8(H(4)) was the major respiratory quinone. The mean (±SD) level of DNA-DNA relatedness between strain YC6903(T) and N. pyridinolyticus OS4(T) was 53.5±5.5 %. The predominant cellular fatty acid of strain YC6903(T) was iso-C(16 : 0) (28.9 %). The DNA G+C content was 71.7 mol%. Phenotypic, phylogenetic and chemotaxonomic data indicated that strain YC6903(T) represents a novel species of the genus Nocardioides, for which the name Nocardioides caricicola sp. nov. is proposed. The type strain is YC6903(T) (=KACC 13778(T) =DSM 22177(T)).

Nocardioides mesophilus sp. nov., isolated from soil

A short coccoid- to rod-shaped, motile, mesophilic actinobacterium, strain MSL-22(T), was isolated from soil on Bigeum Island, Korea. A polyphasic study was undertaken to establish the taxonomic position of this strain. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain MSL-22(T) formed an evolutionary lineage within the radiation of the genus Nocardioides. In particular, it formed a monophyletic lineage with Nocardioides jensenii KCTC 9134(T) with which it shared the highest sequence similarity of about 97.3%. However, DNA-DNA relatedness demonstrated that strain MSL-22(T) was distinct from its closest phylogenetic neighbours. The cell-wall peptidoglycan of strain MSL-22(T) contained LL-diaminopimelic acid. The predominant menaquinone was MK-8(H₄). Strain MSL-22(T) had a cellular fatty acid profile containing straight-chain, branched, unsaturated and 10-methyl fatty acids, with iso-C₁₆:₀ as the major fatty acid. The DNA G+C content of the strain was 68.7 mol%. On the basis of phenotypic and phylogenetic evidence, the strain is separate from previously described members of the genus Nocardioides and represents a novel species in this genus, for which the name Nocardioides mesophilus sp. nov. is proposed. The type strain is MSL-22(T) (=DSM 19432(T)=KCTC 19310(T)).

Nocardioides daedukensis sp. nov., a halotolerant bacterium isolated from soil

A Gram-positive, non-motile and rod- or coccoid-shaped bacterial strain, MDN22(T), was isolated from a soil sample from Korea. Strain MDN22(T) grew optimally at pH 7.0-8.0, at 30 degrees C and in the presence of 0-0.5 % (w/v) NaCl. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain MDN22(T) was phylogenetically most closely related to the genera Nocardioides and Marmoricola. In the neighbour-joining phylogenetic tree, strain MDN22(T) was most closely related to Nocardioides jensenii KCTC 9134(T), with which it exhibited 98.3 % 16S rRNA gene sequence similarity. The strain exhibited 93.1-96.9 % and 95.3-95.9 % 16S rRNA gene sequence similarities to the type strains of other species of the genera Nocardioides and Marmoricola, respectively. The chemotaxonomic properties of strain MDN22(T) were consistent with those of the genus Nocardioides; the cell-wall peptidoglycan type was based on ll-2,6-diaminopimelic acid, the predominant menaquinone was MK-8(H(4)) and the major fatty acids were iso-C(16 : 0) and C(17 : 1). The DNA G+C content was 68.7 mol%. DNA-DNA relatedness data and differential phenotypic properties suggested that strain MDN22(T) could be differentiated from N. jensenii and Nocardioides dubius. On the basis of the data obtained, strain MDN22(T) is considered to represent a novel species of the genus Nocardioides, for which the name Nocardioides daedukensis sp. nov., is proposed. The type strain is MDN22(T) (=KCTC 19601(T)=CCUG 57505(T)).

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

A Gram-positive, rod-shaped, non-spore-forming bacterium (Gsoil 346(T)) was isolated from the soil of a ginseng field in South Korea and was characterized in order to determine its taxonomic position. On the basis of 16S rRNA gene sequences, strain Gsoil 346(T) was shown to belong to the genus Nocardioides in the family Nocardioidaceae, with the most closely related species being Nocardioides aquiterrae GW-9(T) (96.6 % 16S rRNA gene sequence similarity); however, the strain clustered in a distinct branch of the phylogenetic tree with Nocardioides kongjuensis A2-4(T) (96.2 %), Nocardioides aromaticivorans H-1(T) (96.1 %), Nocardioides nitrophenolicus NSP41(T) (96.1 %) and Nocardioides simplex ATCC 15799(T) (95.9 %). Strain Gsoil 346(T) was characterized chemotaxonomically and found to have ll-2,6-diaminopimelic acid in the cell-wall peptidoglycan, phosphatidylinositol and phosphatidylglycerol as the major polar lipids, MK-8(H(4)) as the predominant menaquinone and iso-C(16 : 0), C(18 : 1)omega9c and C(17 : 1)omega8c as the major fatty acids. The G+C content of the genomic DNA of the novel strain was 73.0 mol%. These chemotaxonomic properties supported the placement of strain Gsoil 346(T) in the genus Nocardioides. The results of physiological and biochemical tests, along with the phylogenetic analysis, allowed strain Gsoil 346(T) to be differentiated genotypically and phenotypically from recognized species of the genus Nocardioides. Therefore, strain Gsoil 346(T) represents a novel species, for which the name Nocardioides panacisoli sp. nov. is proposed, with Gsoil 346(T) (=KCTC 19470(T)=DSM 21348(T)) as the type strain.

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

A Gram-positive, rod-shaped, non-spore-forming bacterium (Gsoil 1124(T)) was isolated from soil of a ginseng field of Pocheon province in South Korea, and was characterized in order to determine its taxonomic position. On the basis of 16S rRNA gene sequence similarity, strain Gsoil 1124(T) was shown to belong to the family Nocardioidaceae and related to Nocardioides simplex (98.2 % 16S rRNA gene sequence similarity), Nocardioides aromaticivorans (98.1 %), Nocardioides nitrophenolicus (97.7 %) and Nocardioides kongjuensis (97.5 %). The sequence similarity with any other species with validly published names within the genus Nocardioides was less than 94.5 %. Strain Gsoil 1124(T) was characterized chemotaxonomically as having ll-2,6-diaminopimelic acid in the cell-wall peptidoglycan, MK-8(H(4)) as the predominant menaquinone and iso-C(16 : 0), C(18 : 0), C(16 : 0), and C(18 : 1)omega9c as the major fatty acids. The G+C content of the genomic DNA was 70.2 mol%. The chemotaxonomic properties and phenotypic characteristics supported the affiliation of strain Gsoil 1124(T) to the genus Nocardioides. The results of physiological and biochemical tests, and the low level of DNA-DNA relatedness allowed genotypic differentiation of strain Gsoil 1124(T) from recognized Nocardioides species. Therefore, strain Gsoil 1124(T) is considered to represent a novel species, for which the name Nocardioides ginsengisoli sp. nov. is proposed, with the type strain Gsoil 1124(T) (=KCTC 19135(T)=CCUG 52478(T)=DSM 17921(T)).

Nocardioides caeni sp. nov., isolated from wastewater

A Gram-positive, non-motile, rod- or coccoid-shaped bacterial strain, designated MN8(T), was isolated from sludge of domestic wastewater in Korea, and its taxonomic position was investigated by use of a polyphasic study. Strain MN8(T) grew optimally at pH 6.5-7.5 and 30 degrees C and in the presence of 0-0.5 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain MN8(T) fell within the cluster comprising Nocardioides species, clustering with Nocardioides simplex KCTC 9106(T), Nocardioides aromaticivorans H-1(T), Nocardioides kongjuensis A2-4(T) and Nocardioides nitrophenolicus NSP41(T), with which it shared 98.4-99.0 % 16S rRNA gene sequence similarity. The chemotaxonomic properties of strain MN8(T) were consistent with those of the genus Nocardioides: the cell-wall peptidoglycan type was based on ll-2,6-diaminopimelic acid, the predominant menaquinone was MK-8(H(4)) and the major fatty acids were iso-C(16 : 0) and C(18 : 1)omega9c. The DNA G+C content was 71.5 mol%. Strain MN8(T) exhibited levels of DNA-DNA relatedness of 13-31 % to the type strains of phylogenetically related Nocardioides species and could be differentiated from these species based on differences in phenotypic characteristics. On the basis of the data presented, strain MN8(T) is considered to represent a novel species of the genus Nocardioides, for which the name Nocardioides caeni sp. nov. is proposed. The type strain is MN8(T) (=KCTC 19600(T)=CCUG 57506(T)).