• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.87-87
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• 2013

The interface between nanomaterials and biosystems is emerging as one of the broadest and most dynamic areas of science and technology, bringing together biology, chemistry, physics and many areas of engineering, biomedicine. The combination of these diverse areas of research promised to yield revolutionary advances in healthcare, medicine, and life science. For example, the creation of new and powerful nanosensors that enable direct, sensitive, and rapid analysis of biological and chemical species can advance the diagnosis and treatment of disease, discovery and screening of new drug molecules. Nanowire based sensors are emerging as a powerful and general platform for ultrasensitive and multiplex detection of biological and chemical species. Here, we present the studies about noble metal nanowire sensors that can be used for sensitive detection of a wide-range of biological and chemical species including nucleic acids, proteins, and toxic metal ions. Moreover, the optical and electrochemical applications of noble metal nanowires are introduced. Noble metal nanowires are successfully used as plasmonic antennas and nanoelectrodes, thereby provide a pathway for a single molecule sensor, in vivo neural recording, and molecular injection and detection in a single living cell.

• Journal of Korean Society on Water Environment
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• v.22 no.3
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• pp.527-533
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• 2006

Tetracycline is one of the mostly used antibiotics around the world. The purpose of this study was to evaluate the fate of two different types of tetracycline resistant bacteria in biological wastewater treatment plants. Tetracycline resistant enterics and heterotrophic bacteria were monitored under two different lab-scale experimental conditions. Tetracycline resistant enteric bacteria showed the lower percentages of total enteric bacteria and net specific growth rate in the monitored activated sludge system as compared to tetracycline resistant heterotrophic bacteria. Therefore, total enterics, potentially E.coli, might not be the best indicator microorganism for evaluating the antibiotic resistant bacteria in biological wastewater treatment plant.

• Research in Plant Disease
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• v.29 no.3
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• pp.299-303
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• 2023

Rust symptoms on Meliosma myriantha trees have been noticed during disease surveys in Korea since 2010, with a high disease incidence frequently surpassing 90%. The causal fungus of the rust disease was identified as Neophysopella vitis based on the morphological investigation and molecular sequence analysis of the internal transcribed spacer (ITS) and large subunit (LSU) rDNA regions. This is the first report of rust disease caused by N. vitis on M. myriantha in Korea. A pathogenicity assay proved that M. myriantha serves as the aecial host of N. vitis as spermogonia and aeciospores were produced, which can infect the two uredinial hosts, Boston ivy (Parthenocissus tricuspidata) and Virginia creeper (Parthenocissus quinquefolia).

• Journal of Applied Biological Chemistry
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• v.66
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• pp.512-518
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• 2023

To address inherent weaknesses such as low mechanical strength and limited enzyme loading capacity in conventional chitosan or alginate beads, an additional step involving the exchange of anionic surfactants with hydroxide ions was employed to prepare porous chitosan hydrogel capsules for enzyme immobilization. Consequently, excellent thermal stability and long-term storage stability were confirmed. Furthermore, coating the porous chitosan hydrogel capsules with polydopamine not only improved mechanical stability but also exhibited remarkable enzyme immobilization efficiency (97.6% for M1-D0.5). Additionally, it was demonstrated that the scope of application for chitosan hydrogel beads, prepared using conventional methods, could be further expanded by introducing an additional step of polydopamine coating. The enzyme immobilization matrix developed in this study can be selectively applied to suit specific purposes and is expected to be utilized as a support for the adsorption or covalent binding of various substances.

• Microbiology and Biotechnology Letters
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• v.52 no.2
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• pp.204-207
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• 2024

Here, we report the whole-genome sequence of Myxococcus stipitatus KYC2006, a bacterium whose conditioned media affect the growth of photosynthetic microorganisms such as cyanobacteria and microalgae. The genome of M. stipitatus KYC2006 was assembled into a 10,311,252 bp circular genome with 68.5% of GC content, containing 7,949 protein-coding genes, 12 rRNA genes, and 79 tRNA genes. Further analysis revealed that there are 29 secondary metabolite biosynthetic gene clusters in M. stipitatus KYC2006. These results suggest that M. stipitatus KYC2006 holds a significant potential as a resource for research on the development of biocontrol agents and value-added products from photosynthetic microorganisms.

• Proceedings of the KOSOMBE Conference
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• v.1990 no.11
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• pp.71-74
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• 1990

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.2
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• pp.135-141
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• 2003

The human granulocyte-macrophage colony stimulating factor (hGM-CSF) gene was introduced into tobacco plants. The cell suspension culture was established from leaf-derived calli of the transgenic tobacco plants in order to express and secrete a biologically active hGM -CSF. The recombinant hGM-CSF from the transgenic plant cell culture (prhGM-CSF) was identified as a yield of about 180 ${\mu}$g/L in the culture filtrate, as determined by ELISA. The addition of 0.5 g/L polyvinylpyrrolidone (PVP) to the plant cell culture medium both stabilized the secreted prhGM-CSF and increased the level of production approximately 1.5-fold to 270 ${\mu}$g/L. The biological activity of the prhGM-CSF was confirmed by measuring the proliferation of the hGM-CSF-dependent cell line, TF-1. Interestingly, the specific activity of the prhGM-CSF was estimated to be approximately 2.7 times higher than that of a commercially available preparation from E. coli.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.5
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• pp.311-315
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• 2002

By the in vitro combinatorial mutagenesis, which is a sequential reaction of PCR mutagenesis and in vitro coupled transcription/translation with Escherichia coli S30 extract, S65 and E222 of green fluorescent protein of Aequarea victoria were comprehensively changed to all possible combinations of amino acids, thus totally 400 mutant (including a wild type) proteins were simultaneously produced and their fluorescent properties were analyzed. Although a few mutations had been reported so far at the 222nd position, replacement E222 to all other19 amino acids gave fluorescent signal to the mutants by changing Ser 65 to Ala together. Among the mutants, replacement to G, A, S, Q, H and C gave relatively high fluorescence. The in vitro combinatorial mutagenesis, therefore, has been proved valuable for comprehensive structure-function studies of proteins.

• BMB Reports
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• v.40 no.5
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• pp.656-661
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• 2007

In this report, we describe an optimized method for generation of ephA8 BAC transgenic mice expressing the lacZ reporter gene under ephA8 regulatory sequences. First, we constructed a targeting vector that carries a 1.2 kb ephA8 DNA upstream of its first exon, a lacZ expression cassette, a kanamycin cassette, and a 0.7 kb ephA8 DNA downstream of its first exon. Second, the targeting vector was electroporated into cells containing the ephA8 BAC and pKOBEGA, in which recombinases induce a homologous recombination between the ephA8 BAC DNA and the targeting vector. Third, the FLP plasmid expressing the Flipase was electroporated into these bacteria to eliminate a kanamycin cassette from the recombinant BAC DNA. The appropriate structures of the modified ephA8 BAC DNA were confirmed by Southern analysis. Finally, BAC transgenic mouse embryos were generated by pronuclear injection of the recombinant BAC DNA. Whole mount X-gal staining revealed that the lacZ reporter expression is restricted to the anterior region of the developing midbrain in each transgenic embryo. These results indicate that the ephA8 BAC DNA contains most, if not all, regulatory sequences to direct temporal and spatial expression of the lacZ gene in vivo.

• KSBB Journal
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• v.19 no.5
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• pp.410-414
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• 2004

Fed-batch cultures of Enterococcus faecalis RKY1 were performed to maximize the L(+)-Iactic acid concentration in the bioreactor. The highest lactic acid concentration was obtained at around 225 g/L by intermittent feeding the concentrated glucose media containing 500 g/L of glucose and 15 g/L (or 75 g/L) of yeast extract. However, in all fed-batch cultures, volumetric productivities of lactic acid gradually decreased due to the inhibitory effect of lactic acid produced during the fermentation. The highest value of lactic acid concentration obtained in this work corresponded to around 1.5-fold increase compared with conventional batch fermentation.