• The Plant Pathology Journal
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• v.32 no.4
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• pp.363-370
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• 2016

Pseudomonas syringae pv. actinidiae (Psa) causes bacterial canker disease in kiwifruit. Antibacterial activity of plant essential oils (PEOs) originating from 49 plant species were tested against Psa by a vapor diffusion and a liquid culture assays. The five PEOs from Pimenta racemosa, P. dioica, Melaleuca linariifolia, M. cajuputii, and Cinnamomum cassia efficiently inhibited Psa growth by either assays. Among their major components, estragole, eugenol, and methyl eugenol showed significant antibacterial activity by only the liquid culture assay, while cinnamaldehyde exhibited antibacterial activity by both assays. The minimum inhibitory concentrations (MICs) of estragole and cinnamaldehyde by the liquid culture assay were 1,250 and 2,500 ppm, respectively. The MIC of cinnamaldehyde by the vapor diffusion assay was 5,000 ppm. Based on the formation of clear zones or the decrease of optical density caused by these compounds, they might kill the bacterial cells and this feature might be useful for managing the bacterial canker disease in kiwifruit.

• Journal of Microbiology and Biotechnology
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• v.9 no.6
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• pp.764-772
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• 1999

To develop an enzyme-linked immunosorbent assay (ELISA) for detecting mold, we produced anti-mold polyclonal antibodies by immunizing extracellular polysaccharide (EPS) of Aspergillus flavus or Penicillium citrinum in rabbits subcutaneously. Using the purified antibody (Ab) and Ab-HRP conjugate, a sandwich ELISA for EPS was established. The standard curve of the ELISA showed the detection limit for P citrinum EPS to be $0.003{\;}\mu\textrm{g}/ml$. The cross-reactivities of the anti-P citrinum EPS Ab toward components of P citrinum such as EPS, liquid, and solid culture mycelium were 100, 10.5, and 0.58%, respectively, and those toward components of A. flavus such as EPS, liquid and solid culture mycelium, and spore were 300, 0.67, 0.29, and 0%, respectively. When the reactivities toward culture broths of 59 mold strains were tested by the sandwich ELISA, most of the Aspergillus (16 of 18) and Penicillium (14 of 16) strains along with one of the two Cladosporium strains gave positive signals in the culture broths even when diluted 1,000 fold, while the rest of species such as Fusarium, Absidia, Alternaria, and Candida gave negative signals. When the water extracts of 30 corn samples were analyzed by the sandwich ELISA, the EPS in the com could be detected in the concentration range of $0.1-1.6{\;}\mu\textrm{g}/g$.

• Journal of Microbiology and Biotechnology
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• v.8 no.5
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• pp.461-465
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• 1998

The suspension culture of an anchorage-dependent cell line (Bok-l) from Bombina orientalis was successful in respects of cost and efficiency. The amount of cells obtained from the suspension culture was almost equivalent to that from the anchorage-dependent culture. This result shows the possibility of suspension culture for scale-up. The cells in suspension produced an antibacterial peptide as much as anchorage-dependent cells did. The cell growth ($6.0\times10^6cells/m\ell$) and viability (>80%) at 10 rpm were higher than that at 0 rpm ($1.9\times10^6cells/m\ell$, 65~80%) and 30 rpm ($1.8\times10^6cells/m\ell$ 40~76%). The size of cells became smaller at the agitation rate of 30 rpm. The antibacterial activities of cell extracts from suspension cultured cells were confirmed against gram-negative and gram-positive bacteria by the inhibition zone assay and the liquid growth inhibition assay.

• Journal of Microbiology and Biotechnology
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• v.13 no.5
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• pp.794-799
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• 2003

Enzyme-linked immunosorbent assay (ELISA) was developed for the rapid detection of Fusarium species, known as harmful fungi in food. One of the hybridoma cell lines (lB8) which produced a monoclonal antibody (Mab) specific to Fusarium extracellular polysaccharide (EPS) was screened and the Mab was produced and purified. A detection limit of the sandwich ELISA against F. moniliforme EPS was $0.001\;\mu\textrm{g}/ml$ in the standard curve. Among the 59 strains tested, most Fusarium species showed hight reactivity with Mab lB8, even when the culture broths were diluted 100,000 times. On the other hand, the other genera, except A. versicolor and Trichoderma viride, had no reactivity. When 1 to $100\;\mu\textrm{g}$ of F. moniliforme EPS was spiked into rice, potato, and mandarine orange, the average recoveries were 151%, 84%, and 94%, respectively, determined by sandwich ELISA. The correlation coefficients between the EPS levels determined by sandwich ELISA and the dry mycelial weight of the liquid culture of F. moniliforme, as well as between the EPS and colony forming unit in solid culture of potato, were 0.97 and 0.91, respectively.

• Food Science and Biotechnology
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• v.17 no.6
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• pp.1246-1253
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• 2008

Phyllosticta melochiae, an endophytic fungus isolated from the healthy leaves of Melochia corchorifolia, was screened for the production of an anticancer drug, taxol on modified liquid medium and potato dextrose broth medium in culture for the first time. The presence of taxol was confirmed by spectroscopic and chromatographic methods of analysis. The amount of taxol produced by this fungus was quantified by high performance liquid chromatography. The maximum amount of fungal taxol production was recorded as $274{\mu}g/L$. The production rate was increased to $5.5{\times}1,000$ fold than that found in the culture broth of earlier reported fungus, Taxomyces andreanae. The fungal taxol extracted also showed a strong cytotoxic activity in the in vitro culture of tested human cancer cells by apoptotic assay. The results designate that the fungal endophyte, P. melochiae is an excellent candidate for an alternate source of taxol supply and can serve as a potential species for genetic engineering to enhance the production of taxol to a higher level.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.783-788
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• 2005

To find antitumor components in liquid cultured cell-free broth and the hot water extract from the fruiting body of Hericium erinaceus, polysaccharides were purified and fractionated by DEAE-cellulose ion exchage column chromatography and Sepharose CL-6B gel filtration chromatography. Among various crude polysaccharides and purified polysaccharides the fractions showing immune-activity were determined by NO assay.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.4
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• pp.322-328
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• 2005

Acylhomoserine lactones (AHLs) are known to be the triggering molecules in the quorum sensing mechanism of many gram-negative bacteria. In order to detect AHL inhibitors that are potential biofilm inhibitors, a convenient and sensitive bioassay was developed based on the $\beta$-galactosidase activity ($\beta$-GAL) of a recombinant Agrobacterium tumefaciens strain. A series of commercially available AHLs were tested for inducing $\beta$-GAL at varying concentrations in agar-plate and liquid cultures of the reporter strain. All AHLs tested exhibited a concentration­dependent induction, and octanoyl homoserine lactone (OHL) showed the highest sensitivity with a detection limit of 0.1 nM in the liquid culture assay. When fimbrolide, a known quorum sensing inhibitor, was added, induction of $\beta$-GAL by OHL was repressed. The repression at a constant OHL concentration was dependent on the fimbrolide concentration with the detection limit below 1 ppm, indicating that this assay is a sensitive method for screening AHL inhibitors.

• Mycobiology
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• v.48 no.4
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• pp.326-329
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• 2020

Valuable natural compounds produced by a variety of microorganisms can be used as lead molecules for development of new agrochemicals. Furthermore, high-throughput in vitro screening systems with specific modes of action can increase the probability of discovery of new fungicides. In the current study, a rapid assay tested with various microbes was developed to determine the degree of respiratory inhibition of Saccharomyces cerevisiae in two different liquid media, YG (containing a fermentable carbon source) and NFYG (containing a non-fermentable carbon source). Based on this system, we screened 100 fungal isolates that were classified into basidiomycetes, to find microbial secondary metabolites that act as respiratory inhibitors. Consequently, of the 100 fungal species tested, the culture broth of an IUM04881 isolate inhibited growth of S. cerevisiae in NFYG medium, but not in YG medium. The result is comparable to that from treatment with kresoxim-methyl used as a control, suggesting that the culture broth of IUM04881 isolate might contain active compounds showing the inhibition activity for respiratory chain. Based on the assay developed in this study and spectroscopic analysis, we isolated and identified an antifungal compound (-)-oudemansin A from culture broth of IUM04881 that is identified as Oudemansiella venosolamellata. This is the first report that (-)-oudemansin A is identified from O. venosolamellata in Korea. Taken together, the development of this assay will accelerate efforts to find and identify natural respiratory inhibitors from various microbes.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.617-622
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• 2014

Voacanga globosa (Blanco), a plant endemic to the Philippines, is traditionally used especially by indigenous people of Bataan in the treatment of ulcers, wounds and tumorous growths. This study aimed to provide scientific evidence to therapeutic properties by determining cytotoxic and pro-apoptotic activity of HPLC fractions from leaves on HCT116 human colon carcinoma and A549 human lung carcinoma cell lines. Ethanolic extraction was performed on V globosa leaves followed by hexane and ethyl acetate partitioning. Silica gel column chromatography and high performance liquid chromatography (HPLC) produced MP1, MP2 and MP3 fractions. Cytotoxic activity of the fractions was determined through MTT assay against the cancer cell lines HCT116 and A549 and the non-cancer AA8 Chinese hamster ovarian cell line. Pro-apoptotic activities of the most active fractions were further assessed through DAPI staining, TUNEL assay and JC-1 mitochondrial membrane potential assay with HCT116 cells. While the MPI fraction exerted no significant activity against all cell lines tested, MP2 and MP3 fractions demonstrated high toxicity against HCT116 and A549 cells. The MP3 fraction induced formation of apoptotic bodies, condensed DNA and other morphological changes consistent with apoptosis of HCT116 cells and TUNEL assay showed significant increase in DNA fragmentation over time. In these cells, the MP3 fraction also induced mitochondrial membrane destabilization, which is generally associated with the beginning of apoptosis. Phytochemical analysis demonstrated the presence only of saponins and terpenoids in the MP3 fraction. The results indicate that the MP3 fraction exerts cytotoxic activity on HCT116 cells via induction of apoptosis triggered by loss of mitochondrial membrane potential crucial for cell survival.

• Korean Journal of Pharmacognosy
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• v.35 no.1 s.136
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• pp.6-15
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• 2004

This study was performed to evaluate the hemopoietic effects of 6 species of deer antlers from origins and parts in vitro. CD34 positive cells were isolated and confirmed the its population by FACS analysis. In a week liquid culture, there was any statistical significance between extracts of three parts of six species of deer antlers in the experiments as colony forming assay, proliferation assay, differentiation assay and observation of morphology. However, after 2 weeks- culture with extracts of three parts of six species of deer antlers, colonies were counted. six species of deer antlers, such as middle part of Korean nippon deer, upper part of Chinese nippon deer, upper part of Newzealand horse deer, middle part of Korea horse deer and middle part of Newzealand red deer, significantly increased the CFU-GM (colony forming unit garnulocyte-macrophage) of CD34 positive cells re1atεd to production of leucocytes such as eosinophil, basophil and neutrophil, while only middle part of Korea horse deer significantly increased the BFU-E (burst forming unit-erythroid) at 1 mg/ml seggesting progenting red blood cells (RBC). In the molecular study with CD34+ cells pretreated with cyclophosphamide, antagonist of hemopoietic activity, upper Part of Korean nippon deer and upper part of Chinese nippon deer effectively increased TPO involved in a late pathway of hematopoiesis just like in ELISA assay of IL-3, TPO and GM-CSF. Taken together, these results indicate exσacts of deer antler had some hemopoietic activity still proposing more clinical study and more basic mechanism research.