이하나 교수

The application of transgenic plants to clean up environmental pollution caused by the wastes of heavy metal mining is a promising method for removing metal pollutants from soils. However, the effect of using genetically modified organisms for phytoremediation is a poorly researched topic in terms of microbial community structures, despite the important role of microorganisms in the health of soil. In this study, a comparative analysis of the bacterial and archaeal communities found in the rhizo

Airborne microorganisms have significant effects on human health, and children are more vulnerable to pathogens and allergens than adults. However, little is known about the microbial communities in the air of childcare facilities. Here, we analyzed the bacterial and fungal communities in 50 air samples collected from five daycare centers and five elementary schools located in Seoul, Korea using culture-independent high-throughput pyrosequencing. The microbial communities contained a wide variet

Next-generation sequencing has great potential for application in bacterial transcriptomics. However, unlike eukaryotes, bacteria have no clear mechanism to select mRNAs over rRNAs; therefore, rRNA removal is a critical step in sequencing-based transcriptomics. Duplex-specific nuclease (DSN) is an enzyme that, at high temperatures, degrades duplex DNA in preference to single-stranded DNA. DSN treatment has been successfully used to normalize the relative transcript abundance in mRNA-enriched cDN

A yellow-pigmented, Gram-negative and aerobic bacterial strain, designated AT1026(T), was isolated from a terrestrial sample from the Antarctic. Results of 16S rRNA gene sequence analysis indicated that the Antarctic isolate belonged to the genus Flavobacterium, with the highest sequence similarity to Flavobacterium tegetincola (96.4 %). Cells were non-motile, non-gliding and psychrotolerant, with optimum and maximum temperatures of about 20 and 25 degrees C. Flexirubins were absent. The major i

An actinobacterial strain containing demethylmenaquinone DMK-9(H(4)) as the diagnostic isoprenoid quinone was isolated from a tidal flat sediment sample, from South Korea. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain JC2054(T) represents a distinct phyletic line within the suborder Micrococcineae of the order Actinomycetales. The closest phylogenetic neighbour was Cellulomonas fermentans, with 94.7 % 16S rRNA gene sequence similarity. The novel isolate was strictly a

A Gram-positive bacterial strain containing L-ornithine as the diagnostic diamino acid was isolated from a sea-water-sample from the East Sea, Korea. A phylogenetic analysis based on 16S rRNA gene sequences showed that strain JC1078T represents a phyletic line within the suborder Micrococcineae of the order Actinomycetales, adjacent to the genus Ornithinimicrobium. The highest sequence similarity values to the isolate were observed against Ornithinimicrobium humiphilum (94.3 %) and Kytococcus se

Infection by pathogenic viruses results in rapid epithelial damage and significantly impacts on the condition of the upper respiratory tract, thus the effects of viral infection may induce changes in microbiota. Thus, we aimed to define the healthy microbiota and the viral pathogen-affected microbiota in the upper respiratory tract. In addition, any association between the type of viral agent and the resultant microbiota profile was assessed. We analyzed the upper respiratory tract bacterial con

Two yellow-pigmented, Gram-negative and aerobic bacterial strains, designated AT1013T and AT1047T, were isolated from terrestrial samples of the Antarctic. On the basis of 16S rRNA gene sequence analyses, the two Antarctic strains shared 97.7 % sequence similarity and showed moderate relationships to the genera Chryseobacterium (92.5-95.3 %), Riemerella (92.3-93.5 %), Bergeyella (92.5-92.6 %) and Kaistella (92.5-93.3 %). In phylogenetic analyses, the two isolates formed a robust monophyletic cla

The taxonomic positions of the genera Ruegeria and Silicibacter were evaluated by a polyphasic investigation. It was evident from 16S rRNA gene sequence analysis that both genera are closely related as they formed a monophyletic clade with high sequence similarities (96.9-98.2 %). Several properties commonly found in these taxa strongly suggest that they should be classified in the same genus. Further, a comparative study based on DNA-DNA hybridization, phenotypic characterization and chemotaxon

A strictly aerobic, non-motile, rod-shaped actinomycete strain, named JC2055T, was isolated from a sediment sample of getbol, the tidal flat of Korea. 16S rDNA analysis revealed that the getbol isolate belonged to the genus Nocardioides with the highest sequence similarity to Nocardioides aquiterrae GW-9T (95.5%). The major menaquinone was MK-8(H4) and the predominant cellular fatty acids were iso-16 : 0 and 17 : 1omega8c. Tuberculostearic acid was absent. The G+C content of DNA was 72 mol%. Bas

Two red pigment-producing bacterial strains with a metallic green sheen were isolated from a sediment sample of getbol, the Korean tidal flat. Phylogenetic analysis based on 16S rDNA sequences showed that these isolates represent a phyletic lineage within the gamma-Proteobacteria that is distantly related to the genus Hahella. No bacterial species with validly published names showed > or = 92% 16S rRNA similarity with the getbol isolates. The strains were gram-negative, chemo-organotrophic, aero

Three marine strains of the Cytophaga-Flavobacterium-Bacteroides group, designated JC2050T, JC2051T and JC2052T, were obtained from a single sediment sample of getbol, the Korean tidal flat. Comparative 16S rDNA sequence studies revealed that the test strains were not closely related to any validly published genera and that these strains were only distantly related to the genus Cyclobacterium (88.7-91.2%). Phylogenetic analyses demonstrated that the three getbol isolates formed a distinct monoph

A strictly aerobic, non-motile, rod-shaped actinomycete, designated strain JC2056(T), was isolated from a sediment sample of getbol, the tidal flat of Korea. Results of 16S rRNA gene sequence analysis indicated that the isolate belonged to the genus Nocardioides, with the highest similarity being to Nocardioides luteus KCTC 9575(T) (95.7 %). The major menaquinone was MK-8(H(4)), and predominant cellular fatty acids were iso-16 : 0 and iso-16 : 1 H. The DNA G+C content was 70 mol%. Based on the m

Two strictly aerobic, halophilic strains of the gamma-Proteobacteria, designated JC2042(T) and JC2043(T), were obtained from a sediment sample of getbol, the Korean tidal flat. Comparative 16S rDNA sequence studies revealed that the test strains were related most closely to the type strains of the genera Alteromonas (93.5-95.5 %) and Glaciecola (91.1-93.3 %). Phylogenetic analyses demonstrated that strains JC2042(T) and JC2043(T) formed a distinct monophyletic clade within the family Alteromonad