Martelella suaedae sp. nov. and Martelella limonii sp. nov., isolated from the root of halophytes.

Two Gram-stain-negative, aerobic and endophytic bacterial strains, designated YC7033T and YC7034T, were isolated from the roots of halophytes (Suaeda maritime and Limonium tetragonum, respectively) inhabiting tidal flats of the Sacheon area, Korea. The phylogenetic analyses of 16S rRNA gene sequences showed that the two strains were closely related to Martelella endophytica YC6887T, Martelella mangrovi BM9-1T, Martelella radicis BM5-7T and Martelella mediterranea DSM 17316T at 97.6-99.1 % similarity. Sequence similarities with the type strains of another closely related genus, Rhizobium, were lower than 95.0 %. Both strains contained ubiquinone-10 (Q-10) as the major respiratory quinone system. The G+C contents of the genomic DNA of strains YC7033T and YC7034T were 52.8 and 62.2 mol%, respectively. The major fatty acids of both strain YC7033T and strain YC7034T were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C19 : 0 cyclo ω8c. On the basis of phylogenetic analysis, and biochemical and phenotypic characteristics, strains YC7033T and YC7034T represent two novel species of the genus Martelella, for which the names Martelella suaedae sp. nov. (type strain: YC7033T=KACC 17175T=NBRC 109440T) and Martelella limonii sp. nov. (type strain: YC7034T=KACC 17176T=NBRC 109441T) are proposed, respectively.

Gynuella sunshinyii gen. nov., sp. nov., an antifungal rhizobacterium isolated from a halophyte, Carex scabrifolia Steud.

An antifungal bacterial strain, designated YC6258(T), was isolated from the rhizosphere of a halophyte (Carex scabrifolia Steud.) growing in a tidal flat area of Namhae Island, Korea. Cells of the strain were Gram-stain-negative, facultatively anaerobic, moderately halophilic, rod-shaped and motile by a single polar flagellum. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YC6258(T) formed a phyletic lineage distinct from members of the most closely related genera, Saccharospirillum and Reinekea, with less than 91.2 % sequence similarities. The major cellular fatty acids were C18 : 1ω7c, C16 : 0 and Summed feature 3 (C16 : 1ω7c/ C16 : 1ω6c). The quinone system of strain YC6258(T) consisted mainly of ubiquinone Q-8. The polar lipid profile exhibited phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and unknown lipids. The DNA G+C content was 48.9 mol%. Based on the phylogenetic and phenotypic characteristics, strain YC6258(T) should be classified as a representative of a novel species in a novel genus for which the name Gynuella sunshinyii gen. nov., sp. nov. is proposed. The type strain is YC6258(T) (KCCM 43015(T) = NBRC 109345(T)).

Roseomonas oryzicola sp. nov., isolated from the rhizosphere of rice (Oryza sativa L.).

A Gram-stain-negative, coccobacilli-shaped bacterium, designated YC6724T, was isolated from the rhizosphere of rice in Jinju, Korea. The taxonomy of strain YC6724T was studied using a polyphasic approach. Strain YC6724T grew optimally at 30 °C and pH 7.0-8.0. Comparative 16S rRNA gene sequence analyses showed that the strain was most closely related to Roseomonas soli 5N26T (98.4 % 16S rRNA gene sequence similarity), Roseomonas lacus THG33T(97.3 %) and Roseomonas terrae DS-48T (97.3 %). Sequence similarities with other species of the genus Roseomonas with validly published names were lower than 94.0 %. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain YC6724T formed a distinct phyletic lineage within the genus Roseomonas. Strain YC6724T had DNA-DNA relatedness values of 16.6 %, 44.0 % and 33.2 % with R. soli KACC 16376T, R. terrae KACC 12677T and R. lacus KACC 11678T, respectively. The predominant fatty acids of strain YC6724T were C18 : 1ω7c and/or C18 : 1ω6c, C16 : 0 and C18 : 1 2-OH. The polar lipid profile contained phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol,diphosphatidylglycerol, an unknown aminolipid and two unknown lipids. The G+C content of the genomic DNA was 70.5 mol% and the major quinone was Q-10. Strain YC6724T contained spermidine as the major polyamine. On the basis of phenotypic, chemotaxonomic and molecular data, it is clear that strain YC6724T represents a novel species of the genus Roseomonas, for which the name Roseomonas oryzicola sp. nov. is proposed. The type strain is YC6724T (=KCTC 22478T=NBRC 109439T).

Nitrospirillum irinus sp. nov., a diazotrophic bacterium isolated from the rhizosphere soil of Iris and emended description of the genus Nitrospirillum.

A polyphasic approach was used to characterize a novel nitrogen-fixing bacterial strain, designated YC6995(T), isolated from the rhizosphere soil of Iris ensata var. spontanea (Makino) Nakai inhabiting a wetland located at an altitude of 960 m on Jiri Mountain, Korea. Strain YC6995(T) cells were Gram-negative, and rod-shaped, with motility provided by a single polar flagellum. Optimal growth conditions were 30 °C and pH 7.0. The major fatty acids of strain YC6995(T) were C18:1 ω7c, C18:1 2-OH and C16:0 3-OH. The major respiratory quinone was ubiquinone-10 (Q-10). The polar lipids were phosphatidylethanolamine, phosphatidyldimethylethanolamine, phosphatidylcholine, phosphatidylglycerol and unidentified glycolipids. The genomic DNA G+C content was 64.1 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed strain YC6995(T) to form a phyletic lineage with Nitrospirillum amazonense DSM 2787(T) with a high sequence similarity (97.2 %), but it displayed low sequence similarity with other remotely related genera, including Azospirillum (<93 %), Rhodocista (93.1-93.4 %), and Skermanella (91.2-93.3 %) in the family Alphaproteobacteria. Based on the phenotypic, chemotaxonomic, and phylogenetic evidences, strain YC6995(T) represents a novel species within the genus Nitrospirillum, for which the name Nitrospirillum irinus sp. nov. is proposed. The type strain is YC6995(T) (= KACC 13777(T) = DSM 22198(T)). An emended description of the genus Nitrospirillum is also proposed.

Labrenzia suaedae sp. nov., a marine bacterium isolated from a halophyte, and emended description of the genus Labrenzia.

An endophytic, Gram-staining-negative bacterium was isolated from sterilized roots of a plant, Suaeda maritima, growing on tidal flats. Cells of the strain were motile by means of a single polar flagellum and colonies were pigmented light brown. Strain YC6927(T) was able to grow at 15-37 °C (optimum at 28-30 °C) and at pH 5.0-10.0 (optimum at pH 7.0-8.0). The strain was able to grow at NaCl concentrations of 0-9.0 % (w/v), with optimum growth at 0-5.0 % NaCl. Comparison of 16S rRNA gene sequences showed that the strain was a member of the genus Labrenzia, exhibiting the highest similarity to Labrenzia marina mano18(T) (97.6 % sequence similarity). Strain YC6927(T) produced light-brown carotenoid pigments. The major respiratory quinone was Q-10 and the DNA G+C content was 58.5 mol%. The DNA-DNA relatedness between strain YC6927(T) and closely related strains was between 8.2±1.8 and 20.3±1.5 %. Strain YC6927(T) contained summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C14 : 0 3-OH as major fatty acids, confirming the affiliation of the strain with the genus Labrenzia. The polar lipids consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylmonomethylethanolamine, an unknown aminolipid, an unknown phospholipid and five unknown lipids. On the basis of phylogenetic analysis, physiological and biochemical characterization and DNA-DNA hybridization data, strain YC6927(T) should be assigned to a novel species of the genus Labrenzia, for which the name Labrenzia suaedae sp. nov. is proposed. The type strain is YC6927(T) ( = KACC 13772(T) = DSM 22153(T)). An emended description of the genus Labrenzia is also proposed.

Mucilaginibacter gynuensis sp. nov., isolated from rotten wood.

A Gram-staining-negative, rod-shaped, aerobic bacterial strain designated YC7003(T), was isolated from a piece of rotten wood collected at Jinju, Korea. The taxonomic position of the strain was investigated using a polyphasic approach. The strain was catalase- and oxidase-positive, grew at 4-35 °C (optimum, 30 °C) and at pH 5.0-10.0 (optimum, pH 6.5-7.0). The major cellular fatty acids were C(16:1)ω7c and/or iso-C(15:0) 2-OH (summed feature 3), iso-C(15:0) and C(16 : 1)ω5c and the major respiratory quinone was MK-7. The total genomic DNA G+C content was 49.0 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YC7003(T) belonged to the genus Mucilaginibacter in the family Sphingobacteriaceae with 94.4-97.2% sequence similarities with type strains of species of the genus Mucilaginibacter. The most closely related species was Mucilaginibacter mallensis MP1X4(T) (97.2%). The DNA-DNA relatedness value between strain YC7003(T) and M. mallensis MP1X4(T) was 21.7 ± 3.3%. Based on these data, strain YC7003(T) represents a novel species of the genus Mucilaginibacter, for which the name Mucilaginibacter gynuensis sp. nov. is proposed. The type strain is YC7003(T) ( =KACC 15532(T) =JCM 17705(T)).

Martelella endophytica sp. nov., an antifungal bacterium associated with a halophyte.

A Gram-staining-negative, non-spore-forming endophytic bacterium, designated strain YC6887(T), was isolated from a root sample of a halophyte, Rosa rugosa, collected from a tidal flat area of Namhae Island, located at the southern end of Korea. Strain YC6887(T) was found to exhibit inhibitory activity against oomycete plant pathogens. The cells were non-motile and aerobic rods. The strain was able to grow at 4-40 °C (optimum 28-30 °C) and at pH 5.0-9.0 (optimum pH 7.0-8.5). Strain YC6887(T) was able to grow at NaCl concentrations of 0-9 % (w/v) with optimum growth at 4-5 % (w/v) NaCl, but NaCl is not essential for growth. Comparison of 16S rRNA gene sequences showed that the strain was a member of the genus Martelella, a member of order Rhizobiales, exhibiting highest similarity with Martelella mediterranea (98.6 %). The DNA-DNA relatedness between strain YC6887(T) and M. mediterranea MACL11(T) was 19.8 ± 6.8. Chemotaxonomically, strain YC6887(T) contained C19 : 0 cyclo ω8c (28.0 %) and C18 : 1ω7c (17.9 %) as predominant fatty acids, confirming the affiliation of strain YC6887(T) with the genus Martelella. The major respiratory quinone was Q-10 and the DNA G+C content was 62.1 mol%. On the basis of phylogenetic analysis, physiological and biochemical characterization and DNA-DNA hybridization data, strain YC6887(T) should be classified as representing a novel species of the genus Martelella, for which the name Martelella endophytica sp. nov. is proposed. The type strain is YC6887(T) ( = KCCM 43011(T) = NBRC 109149(T)).

Mucilaginibacter jinjuensis sp. nov., with xylan-degrading activity.

A gram-negative, rod-shaped, pale-orange-pigmented bacterial strain with xylan-degrading activity designated YC7004(T) was isolated from a rotten-wood sample collected at Jinju, Korea, and its taxonomic position was investigated by using a polyphasic approach. The strain grew optimally on R2A medium at 30 °C and at pH 6. The major isoprenoid quinone was MK7 and major fatty acids were summed feature 3, iso-C15 : 0, C16 : 0, iso-C17 : 0 3-OH, iso-C17 : 1ω9c and C16 : 1ω5c. The G+C content of the genomic DNA was 40.0 mol%. Phylogenetic analysis based on the 16S rRNA gene sequences showed that the strain belongs to the genus Mucilaginibacter in the family Sphingobacteriaceae. The most closely related species were Mucilaginibacter daejeonensis (95.5 %), Mucilaginibacter frigoritolerans (94.6 %) and Mucilaginibacter mallensis (94.0 %). Based on the phylogenetic and chemotaxonomic data analyses, strain YC7004(T) represents a novel species of the genus Mucilaginibacter with the proposed name of Mucilaginibacter jinjuensis sp. nov. The type strain is YC7004(T) ( = KACC 16571(T) = NBRC 108856(T)).

Hoeflea suaedae sp. nov., an endophytic bacterium isolated from the root of the halophyte Suaeda maritima.

A Gram-negative, aerobic, short rod-shaped bacterium, designated strain YC6898(T), was isolated from the surface-sterilized root of a halophyte (Suaeda maritima) inhabiting tidal flat of Namhae Island, Korea. Strain YC6898(T) grew optimally at 30-37 °C and pH 6.5-7.5. The strain inhibited mycelial growth of Pythium ultimum and Phytophthora capsici. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain YC6898(T) belongs to the genus Hoeflea in the family Phyllobacteriaceae. Its closest relatives were Hoeflea alexandrii AM1V30(T) (96.7% 16S rRNA gene sequence similarity), Hoeflea anabaenae WH2K(T) (95.7%), Hoeflea phototrophica DFL-43(T) (95.5%) and Hoeflea marina LMG 128(T) (94.8%). Strain YC6898(T) contained Q-10 as the major ubiquinone. The major fatty acids of strain YC6898(T) were C18:1ω7c (61.1%), C16:0 (11.9%), 11-methyl C18:1ω7c (9.6%) and C19:0 cyclo ω8c (8.0%). The polar lipids were phosphatidylcholine, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylglycerol, unknown lipids and an unknown glycolipid. The total genomic DNA G+C content was 53.7 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic analysis, strain YC6898(T) represents a novel species of the genus Hoeflea, for which the name Hoeflea suaedae sp. nov. is proposed. The type strain is YC6898(T) (=KACC 14911(T)=NBRC 107700(T)).

Amorphus suaedae sp. nov., isolated from the root of a tidal flat plant, Suaeda maritima.

A novel bacterial strain, YC6899(T), was isolated from the root of Suaedae maritima growing on a tidal flat of Namhae Island, Korea. Cells were Gram-reaction-negative, rod-shaped, non-motile, slightly halophilic and heterotrophic. Strain YC6899(T) grew optimally at a salinity of 2-4 %, at 25-37 °C and at pH 6.5-8.0. Phylogenetic analysis of 16S rRNA gene sequences demonstrated that strain YC6899(T) was closely related to Amorphus orientalis YIM D10(T) (96.1 % similarity) and Amorphus coralli RS.Sph.026(T) (95.9 %). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, unknown aminolipids, an unknown aminophospholipid, an unknown aminoglycolipid, unknown glycolipids and unknown lipids. The major fatty acids of strain YC6899(T) were C19 : 0 cyclo ω8c and C18 : 1ω7c. The G+C content of the genomic DNA was 61.3 mol%. Strain YC6899(T) contained ubiquinone-10 (Q-10) as the major respiratory quinone system. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain YC6899(T) represents a novel species within the genus Amorphus, for which the name Amorphus suaedae sp. nov. is proposed. The type strain is YC6899(T) ( = KACC 14912(T) = NBRC 107845(T)).

Rhizobium halophytocola sp. nov., isolated from the root of a coastal dune plant.

During a study of endophytic bacteria from coastal dune plants, a bacterial strain, designated YC6881(T), was isolated from the root of Rosa rugosa collected from the coastal dune areas of Namhae Island, Korea. The bacterium was found to be Gram-staining-negative, motile, halophilic and heterotrophic with a single polar flagellum. Strain YC6881(T) grew at temperatures of 4-37 °C (optimum, 28-32 °C), at pH 6.0-9.0 (optimum, pH 7.0-8.0), and at NaCl concentrations in the range of 0-7.5% (w/v) (optimum, 4-5% NaCl). Strain YC6881(T) was catalase- and oxidase-positive and negative for nitrate reduction. According to phylogenetic analysis using 16S rRNA gene sequences, strain YC6881(T) belonged to the genus Rhizobium and showed the highest 16S rRNA gene sequence similarity of 96.9% to Rhizobium rosettiformans, followed by Rhizobium borbori (96.3%), Rhizobium radiobacter (96.1%), Rhizobium daejeonense (95.9%), Rhizobium larrymoorei (95.6%) and Rhizobium giardinii (95.4%). Phylogenetic analysis of strain YC6881(T) by recA, atpD, glnII and 16S-23S intergenic spacer (IGS) sequences all confirmed the phylogenetic arrangements obtained by using 16S rRNA gene sequences. Cross-nodulation tests showed that strain YC6881(T) was a symbiotic bacterium that nodulated Vigna unguiculata and Pisum sativum. The major components of the cellular fatty acids were C(18:1)ω7c (53.7%), C(19:0) cyclo ω8c (12.6%) and C(12:0) (8.1%). The DNA G+C content was 52.8 mol%. Phenotypic and physiological tests with respect to carbon source utilization, antibiotic resistance, growth conditions, phylogenetic analyses of housekeeping genes recA, atpD and glnII, and fatty acid composition could be used to discriminate strain YC6881(T) from other species of the genus Rhizobium in the same sublineage. Based on the results obtained in this study, strain YC6881(T) is considered to represent a novel species of the genus Rhizobium, for which the name Rhizobium halophytocola sp. nov. is proposed. The type strain is YC6881(T) ( = KACC 13775(T) = DSM 21600(T)).

Chitinophaga oryziterrae sp. nov., isolated from the rhizosphere soil of rice (Oryza sativa L.).

A novel bacterial strain, YC7001(T), was isolated from the rhizosphere soil of rice collected at Jinju, Korea, and was characterized using a polyphasic approach. Cells of strain YC7001(T) were Gram-negative-staining, yellow-pigmented, rod-shaped, aerobic, heterotrophic and non-motile. Strain YC7001(T) grew optimally at 25-30 °C, pH 5.0-8.0 and degraded gelatin, cellulose and chitin. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain YC7001(T) belonged to the genus Chitinophaga in the family Chitinophagaceae. The most closely related species were Chitinophaga sancti NBRC 15057(T) (96.9%), Chitinophaga ginsengisoli Gsoil 052(T) (95.9%), Chitinophaga pinensis DSM 2588(T) (95.7%), Chitinophaga filiformis IFO 15056(T) (95.7%) and Chitinophaga niabensis JS13-10(T) (95.0%). The DNA-DNA relatedness value of strain YC7001(T) with C. sancti NBRC 15057(T) was 15.2 ± 0.6%. Strain YC7001(T) contained MK-7 as the major menaquinone and homospermidine as the major polyamine. The major fatty acids of strain YC7001(T) were C(15:0) iso, C(16:1)ω5c and C(17:0) iso 3-OH. The polar lipids were phosphatidylethanolamine, unknown aminolipids and unknown lipids. The total genomic DNA G+C content was 41.3 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic analyses, strain YC7001(T) represents a novel species of the genus Chitinophaga, in the family Chitinophagaceae, for which the name Chitinophaga oryziterrae sp. nov. is proposed. The type strain is YC7001(T) ( = KACC 14533(T) = JCM 16595(T)).

Metabolic engineering of Escherichia coli for α-farnesene production.

Sesquiterpenes are important materials in pharmaceuticals and industry. Metabolic engineering has been successfully used to produce these valuable compounds in microbial hosts. However, the microbial potential of sesquiterpene production is limited by the poor heterologous expression of plant sesquiterpene synthases and the deficient FPP precursor supply. In this study, we engineered E. coli to produce α-farnesene using a codon-optimized α-farnesene synthase and an exogenous MVA pathway. Codon optimization of α-farnesene synthase improved both the synthase expression and α-farnesene production. Augmentation of the metabolic flux for FPP synthesis conferred a 1.6- to 48.0-fold increase in α-farnesene production. An additional increase in α-farnesene production was achieved by the protein fusion of FPP synthase and α-farnesene synthase. The engineered E. coli strain was able to produce 380.0 mg/L of α-farnesene, which is an approximately 317-fold increase over the initial production of 1.2 mg/L.

Bacillus graminis sp. nov., an endophyte isolated from a coastal dune plant.

A Gram-stain-positive endophytic bacterium, designated strain YC6957(T), was isolated from surface-sterilized roots of a halophyte (Elymus mollis Trin.) inhabiting coastal tidal flats of Namhae Island, located on the southern coast of Korea, and was subjected to a polyphasic taxonomic study. Cells were facultatively anaerobic, endospore-forming rods to coccoid rods, motile by a single flagellum. Strain YC6957(T) was catalase-positive, oxidase-negative and able to grow in the presence of 0-8 % (w/v) NaCl, with optimum growth at 4-5 % (w/v) NaCl. Growth occurred at 15-45 °C (optimal growth at 30-35 °C) and pH 6.0-8.5 (optimal growth at pH 7.0-8.0). The predominant isoprenoid quinone was menaquinone 7 (MK-7). The major cellular fatty acids were C(16 : 0) (11.3 %), iso-C(15 : 0) (19.2 %) and anteiso-C(15 : 0) (36.4 %). The cell-wall peptidoglycan contained meso-diaminopimelic acid. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The DNA G+C content was 41.6 mol%. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the isolate belonged to the genus Bacillus. Strain YC6957(T) exhibited high 16S rRNA gene sequence similarity to its closest neighbours, Bacillus ruris LMG 22866(T) (96.14 %), Bacillus lentus NCIMB 8773(T) (95.97 %) and Bacillus galactosidilyticus LMG 17892(T) (95.91 %), and less than 95.84 % similarity to all other type strains in the genus Bacillus. On the basis of the phylogenetic, physiological and biochemical data, it is suggested that strain YC6957(T) represents a novel species of the genus Bacillus, for which the name Bacillus graminis sp. nov. is proposed. The type strain is YC6957(T) ( = KACC 13779(T)  = DSM 22162(T)).

Haloferula luteola sp. nov., an endophytic bacterium isolated from the root of a halophyte, Rosa rugosa, and emended description of the genus Haloferula.

A Gram-negative, non-spore-forming, endophytic bacterium, strain YC6886(T), was isolated from the root of a halophyte, Rosa rugosa, which inhabits coastal areas of Namhae Island off the southern coast of Korea. Cells were non-motile, obligately aerobic rods and formed pale-yellow colonies. The isolate grew at 4-32 °C (optimum 25-28 °C) and at pH 6.5-9.5 (optimum pH 7.5) and grew optimally with 2-3 % (w/v) NaCl, but NaCl was not an absolute requirement for growth. Strain YC6886(T) produced yellow carotenoid pigments. Strain YC6886(T) exhibited the highest 16S rRNA gene sequence similarity with Haloferula sargassicola MN1-1037(T) (97.4 %). Sequence similarities between strain YC6886(T) and other members of the genus Haloferula were 93.9-94.7 %. DNA-DNA relatedness between strain YC6886(T) and H. sargassicola KCTC 22202(T) and Haloferula rosea KCTC 22201(T) was 27 and 15 %, respectively. The major fatty acids were iso-C(14 : 0), C(16 : 0) and C(16 : 1)ω9c and minor components were C(14 : 0), C(18 : 0) and anteiso-C(15 : 0). The major respiratory quinone was menaquinone 9 and the DNA G+C content was 58.5 mol%. The polar lipid profile was composed of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, an unknown phospholipid and an unknown phosphoglycolipid. On the basis of phenotypic, chemotaxonomic, DNA-DNA hybridization and phylogenetic analysis, strain YC6886(T) represents a novel species in the genus Haloferula, for which the name Haloferula luteola sp. nov. is proposed. The type strain is YC6886(T) ( = KCTC 22447(T)  = DSM 21608(T)). An emended description of the genus Haloferula is also presented.

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)).

Sphingomonas oryziterrae sp. nov. and Sphingomonas jinjuensis sp. nov. isolated from rhizosphere soil of rice (Oryza sativa L.).

Two Gram-reaction-negative, yellow-orange-pigmented, rod-shaped bacterial strains, designated YC6722(T) and YC6723(T), were isolated from rhizosphere soil samples collected from rice fields in Jinju, Korea. Strains YC6722(T) and YC6723(T) grew optimally at 25-30 °C and at pH 7.0-8.5. Phylogenetic analyses of 16S rRNA gene sequences showed that strain YC6722(T) was most closely related to Sphingomonas jaspsi TDMA-16(T) (96.6 % sequence similarity) and strain YC6723(T) was related most closely to Sphingomonas aquatilis JSS7(T) (96.9 %). The two strains contained ubiquinone-10 (Q-10) as the major respiratory quinone system and sym-homospermidine as the major polyamine. The G+C contents of the genomic DNA of strains YC6722(T) and YC6723(T) were 63.3 and 61.0 mol%, respectively. The major fatty acid was C(18 : 1)ω7c. The polar lipids detected in the two strains were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, sphingoglycolipid, phosphatidyldimethylethanolamine and other unknown lipids. On the basis of their phylogenetic positions, and their biochemical and phenotypic characteristics, strains YC6722(T) and YC6723(T) represent two novel species of the genus Sphingomonas, for which the names Sphingomonas oryziterrae sp. nov. ( = KCTC 22476(T)  = DSM 21455(T)) and Sphingomonas jinjuensis sp. nov. (KCTC 22477(T)  = DSM 21457(T)) are proposed.

Chitinophaga eiseniae sp. nov., isolated from vermicompost.

A Gram-negative, rod-shaped bacterial strain, YC6729(T), was isolated from vermicompost collected at Masan, Korea, and its taxonomic position was investigated by a polyphasic taxonomic approach. Strain YC6729(T) grew optimally at 30 °C and at pH 6.5-8.5. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain YC6729(T) belongs to the genus Chitinophaga in the family Chitinophagaceae. It was related most closely to Chitinophaga terrae KP01(T) (96.4 % 16S rRNA gene sequence similarity), Chitinophaga ginsengisegetis Gsoil 040(T) (96.1 %), Chitinophaga arvensicola IAM 12650(T) (96.1 %) and Chitinophaga pinensis DSM 2588(T) (93.3 %). Strain YC6729(T) contained MK-7 as the major menaquinone and homospermidine as the major polyamine. The fatty acids of strain YC6729(T) were iso-C(15 : 0), C(16 : 1)ω5c, iso-C(17 : 0) 3-OH, C(16 : 0), anteiso-C(18 : 0) and/or C(18 : 2)ω6,9c, iso-C(15 : 0) 2-OH and/or C(16 : 1)ω7c, C(14 : 0), iso-C(15 : 0) 3-OH, iso-C(15 : 1) G, C(18 : 1)ω5c, iso-C(15 : 1) I and/or C(13 : 0) 3-OH, C(13 : 0) 2-OH, C(16 : 0) 3-OH and unknown fatty acid ECL 13.565. The polar lipid profile contained phosphatidylethanolamine, unknown aminolipids and unknown lipids. The total DNA G+C content of strain YC6729(T) was 48.9 mol%. The phenotypic, chemotaxonomic and phylogenetic data showed that strain YC6729(T) represents a novel species of the genus Chitinophaga, for which the name Chitinophaga eiseniae sp. nov. is proposed. The type strain is YC6729(T) ( = KACC 13774(T)  = DSM 22224(T)).

Isolation and Characterization of an Acidic, Salt-Tolerant Endoglucanase Cel5A from a Bacterial Strain Martelella endophytica YC6887 Genome.

A Martelella endophytica (M. endophytica) strain YC6887 was previously isolated from the roots of a halophyte, Rosa rugosa, which was sequenced and characterized. The genomic and proteomic analysis showed a carbohydrate-degrading enzyme, endoglucanase Cel5A which was further characterized. The protein analysis revealed that this endoglucanase belongs to glycosidic hydrolase family 5 (GH5) with catalytic domain. This gene encodes 349-residue polypeptide and shows closest similarity with cellulases of other Martelella species. The protein was purified to homogeneity and shown that it was a 39 kDa protein. The purified recombinant Cel5A endoglucanase exhibited maximum activity at 50 °C and pH 4.5. The enzyme was salt tolerant and retained more than 50% residual activity up to 15% NaCl. The homology model structure of Cel5A displayed that it is stable and compact protein structure consisting of eleven α-helical structures and eight ß-sheets. According to the predicted ligand binding site after superimposition with Pseudomonas stutzeri endoglucanase Cel5A (PDB ID: 4LX4), it consisted of five amino acid Asn157, Tyr116, Glu158, Glu270 and Trp303 that may be the expected active site of Cel5A from YC6887. This presented that our strain M. endophytica YC6887 that produces cellulase partially degrade the insoluble polysaccharides into reducing sugars.

Farnesol production from Escherichia coli by harnessing the exogenous mevalonate pathway.

Farnesol (FOH) production has been carried out in metabolically engineered Escherichia coli. FOH is formed through the depyrophosphorylation of farnesyl pyrophosphate (FPP), which is synthesized from isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP) by FPP synthase. In order to increase FPP synthesis, E. coli was metabolically engineered to overexpress ispA and to utilize the foreign mevalonate (MVA) pathway for the efficient synthesis of IPP and DMAPP. Two-phase culture using a decane overlay of the culture broth was applied to reduce volatile loss of FOH produced during culture and to extract FOH from the culture broth. A FOH production of 135.5 mg/L was obtained from the recombinant E. coli harboring the pTispA and pSNA plasmids for ispA overexpression and MVA pathway utilization, respectively. It is interesting to observe that a large amount of FOH could be produced from E. coli without FOH synthase by the augmentation of FPP synthesis. Introduction of the exogenous MVA pathway enabled the dramatic production of FOH by E. coli while no detectable FOH production was observed in the endogenous MEP pathway-only control.