• Environmental Mutagens and Carcinogens
• /
• v.25 no.4
• /
• pp.157-160
• /
• 2005

Antibiotic resistance of bacteria in the biofilm mode of growth contributes to the chronicity of infection and disease. The penetration of antibiotic, through biofilm developed in an itt vitro model system was investigated. Antibiotic resistant bacteria (E. coli) were obtained from Culture Collection of Antibiotic Resistant Microbes. Ca-alginate bead used as simulated biofilm and a cell entrapment test using compressed air were experiment for the improvement cell viability. Antibiotic susceptibilities though biofilms was measured by assaying the concentration of antibiotic that diffused through the biofilm to minimal inhibition concentration (MIC). Survival of immobilized cells were reduced as compared to free cells. In case of antibiotic susceptible E. coli reduced continuously, but antibiotic resistant E. coli kept up survival rate constantly. Survival was showed after exposed to the antibiotics that the more treated antibiotic resistant E. coli and low concentration of antibiotics) the more survived.

• Journal of Korean Society of Water and Wastewater
• /
• v.24 no.1
• /
• pp.51-62
• /
• 2010

The high concentration of N in the wastewater from livestock farming generally renders the efficiency of the wastewater treatment. Therefore, removal of N in livestock wastewater is crucial for successful treatment. The current study was conducted to investigate the optimum conditions for partial nitrification under anaerobic condition following nitritation in TPAD-BNR(two-phase anaerobic digestion-biological nitrogen removal) operating system. Sequential operating test to stimulate partial nitrification in reactor showed that partial nitrification occurred at a ratio of 1.24 in $NO_2{^-}$-N:$NH_4{^+}$-N. With this result, a wide range of factors affecting stable nitritation were examined through regression analysis. In the livestock wastewater treatment procedure, the hydraulic retention time (HRT) and pH range for optimum nitrite accumulation in the reactor were 1-1.5 days and 7-8, respectively. It was appeared that accumulation of $NO_2{^-}$-N in the reactor is due to inhibition of the $NO_2{^-}$-N oxidizer by free ammonia (FA) while the effect of free nitrous acid was minimal. Nitrification was not influenced by DO concentration at a range of 2.0-3.0 mg/L and the difference in the growth rate between $NH_4{^+}$-N oxidizer and $NO_2{^-}$-N oxidizer was dependent on the temperature in the reactor.

• Journal of the Korean Wood Science and Technology
• /
• v.48 no.1
• /
• pp.107-116
• /
• 2020

Termiticidal and fungicidal activities of wood vinegar from Cinnamomum parthenoxylon (CP) stem wood have been evaluated against Coptotermes curvignathus and wood rotting fungi (Schizophyllum commune and Fomitopsis palustris). The utilized CP wood vinegar was produced in the operating temperature range 250-300℃ pyrolysis. A no-choice test was applied for evaluating termiticidal activity with 33 active termites and antifungal activity using the agar media assay. The result showed that an increase in the concentrations of CP wood vinegar significantly raised the mortality of termite. CP wood vinegar showed high termiticidal activity, organic acids (acetic acid 42.91%, 3-butenoic acid 6.89%, butanoic acid, 2-propenyl ester 2.26%), and ketones (1-hydroxy-2-propanone 5.14%, 3-methylcyclopentane-1,2-dione 2.34%) might be largely contributed to termiticidal activity in addition to other minor components. Furthermore, CP wood vinegar exhibited significant inhibition of fungal growth. These data showed that CP wood vinegar was more toxic to white-rot fungi (S. commune) than brown-rot (F. palustris). The results suggested that phenolic compounds from lignin degradation were responsible for good antifungal activity.

• YAKHAK HOEJI
• /
• v.48 no.3
• /
• pp.189-196
• /
• 2004

Matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) playa key role in tumor invasion and metastasis. As an inhibitor of MMP-2, TIMP-2 is known to block both the invasive and metastatic behavior of cancer cells, and decrease tumor growth activity. We performed this study to investigate the effects of TIMP-2 over-expression induced by retroviral mediated gene transfer in vitro and in vivo. The human colon cancer cell line SW480 was transfected with the retroviral vector encoding TIMP-2. The effects of TIMP-2 over-expression were analyzed by invasion assay and gelatinase activity test in colon cancer cells and tumorigencity in nude mice. In evaluation of the transfection efficiency of the retroviral vector encoding TIMP-2 in colon cancer cells, we confirmed up-regulation of TIMP-2 expression dependent on the time of cell culture. In addition, inhibition of MMP-2 expression in SW480/TIMP-2 was shown by gelatin zymography. In the in vitro invasion assay SW480/TIMP-2 inhibited the invasiveness on matrigel coated with collagen. To determine whether TIMP-2 can modulate in vivo tumorigenicity and metastasis, SW480/TIMP-2 cells were injected subcutaneously in nude mice. The tumor mass formation of SW480/TIMP-2 cells in nude mice was markedly decreased compared to nontransfected cancer cells. These results showed that colon cancer cells transfected with the retroviral vector encoding TIMP-2 inhibits the invasiveness in vitro and tumorigenicity in vivo.

• YAKHAK HOEJI
• /
• v.41 no.4
• /
• pp.450-455
• /
• 1997

The preparation of Bacillus coagulans is used as a therapeutics for human intestinal disorders. However, the bacterium in the preparation is very susceptible to rifampic in and fluoroquinolones. When the preparation is taken with rifampicin or fluoroquinolones, its therapeutic effect can not be expected. So B. coagulans RFR17 resistant to rifampicin was obtained by treating the parent B. coagulans with N-methyl-N'-nitro-N-nitrosoguanidine. B. coagulans OFR17 was produced by serial passage of B. coagulans RFR17 on agar with 2-fold minimal inhibitory concentration of ofloxacin or ciprofloxacin. B. coagulans OFR17 was resistant to fluoroquinolones up to 16~64 fold higher than that for the original strain. B. coagulans OFR17 also exhibited identical characteristics with the parent strain when they were tested for lactic acid production and growth inhibition of E. coli MB4-01 and Shigella sonnei MB4-10411. From in vitro test, it was also identified that rifampicin and ofloxacin are not inactivated by certain factors of B. coagulans OFR17. Conclusively, B. coagulans OFR17 can be regarded as a promising strain which can be developed as the preparation for the treatment of the intestinal disorders of the tuberculosis patients under rifampicin and ofloxacin therapy.

• Korean Journal of Agricultural Science
• /
• v.47 no.4
• /
• pp.1011-1020
• /
• 2020

Efficient management systems of facilities make it possible to manage environmental conditions properly, such as the temperature, humidity and light source required for the best growth of the crops, as well as for the mass production of fruit and vegetables with high quality every year through an advanced and protected cultivation system. Powdery mildew is a type of chronic disease that is difficult to control during the production of Korean melons under a protected cultivation system, the use of which is increasing in production areas in Korea. Two Bacillus strains isolated from soil samples showed antagonistic activities against several pathogens, specifically Botrytis cinerea, Colletotrichum gloeosporioides, and Fusarium oxysporum f.sp. melonis; they were identified as Bacillus velezensis M2 and B. amyloliquefaciens M3 in a molecular biological test of the nucleotide sequences of gyrase subunit A (gyrA). The treatment was given three times at intervals of five days with 400-fold diluted cultures of B. velezensis M2 and B. amyloliquefaciens M3. This led to the inhibition of the incidence of powdery mildew disease in Korean melon leaves, which resulted in effective control efficiency against the incidence of powdery mildew disease with control values of 87% and 65%, respectively. Cultures of antagonistic microbes tested in this study can be used to increase the efficiency as part of an environmentally friendly management scheme to prevent powdery mildew disease during the protected cultivation of crops, including Korean melons.

• Research in Plant Disease
• /
• v.27 no.4
• /
• pp.164-171
• /
• 2021

In August 2020, 377 anthracnose strains were isolated from anthracnose-infected peppers collected from 25 farms in Sunchang-gun, Jeollabuk-do. Inhibition rate of mycelial growth of 11 pepper anthracnose fungicides registered in Korea was investigated for 62 strains selected by region and the degree of susceptibility to each fungicide was investigated. As a result of the fungicide susceptibility test of anthracnose to the fungicide, no resistant strains were observed in fluazinam, prochloraz manganese, and benomyl, but resistant strains appeared in at least three areas for other fungicides, and all strains in all regions were resistant to dithianon. Through this, it was confirmed that the fungicide resistance was expressed in the strain group due to the continuous treatment of the fungicide in some areas. By region, resistant strains to seven pesticides appeared in Sunchang-eup and Paldeok-myeon, and resistant strains to six pesticides appeared in Geumgwa-myeon, Bokheung-myeon, Ssangchi-myeon, Yudeung-myeon, and Pungsan-myeon. There was no significant correlation between fungicide registration time and emergence of resistant strains.

• Journal of the Korean Wood Science and Technology
• /
• v.31 no.1
• /
• pp.1-9
• /
• 2003

Antimicrobial activities of plant extractives were investigated to develop a natural fungicide. Two stilbenoids and five flavonoids were isolated from wood extractives of Hovenia dulcis (Rhamnaceae) which had been selected due to its high antifungal activity among the tested species. The chemical structures of isolated compounds were determinded as : 5-hydroxy-7-methoxyflavone, 5,7-dihydroxyflavone (chrysin), 5,7-dihydroxyflavanone (pinocembrin), 3,5,7-trihydroxyflavanone (pinobanksin), 3,4',5,7-tetrahydroxyflavanone (aromadendrin), 3-hydroxy-5-methoxystilbene and 3,5-dihydroxystilbene (pinosylvin) on the basis of Mass and NMR spectroscopic data. According to the results of antifungal test, 3-hydroxy-5-methoxystilbene was evaluated as the strongest antifungal compound among the tested compounds and next were pinocembrin and pinosylvin, but those also had high hyphal growth inhibition activities against C. parasitica, T. versicolor, T. palustris and T. viride. However, pinobanksin, 5-hydroxy-7-methoxyflavone, chrysin and aromadendrin showed very low antifungal activity. In this regard, it could inferred that high antifungal activity of wood extractives of H. dulcis were derived from 3-hydroxy-5-methoxystilbene, pinocembrin and pinosylvin, respectively.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.21 no.6
• /
• pp.655-661
• /
• 2015

This study intends to evaluate the effect of nitric acid($HNO_3$) spill accidents on the marine ecosystem, while $HNO_3$ is known as one of the typical HNS. For this purpose, we performed (1) the growth inhibition test by using phytoplankton(Skeletonema costatum), (2) acute and chronic toxicity test by using invertebrate(Brachionus plicatilis and Monocorphium acherusicum), (3) fish(Cyprinodon variegatus) and (4) bacteria(Vibrio fischeri). In these tests, we observed the (1) pH changes induced by the nitric acid spill and (2) changes in nitrate($NO_3$) concentration disassociated from nitric acid after the accident, respectively. The toxicity test result on pH changes induced by $HNO_3$ shows that the no observed effect concentration(NOEC), lowest observed effect concentration(LOEC) and 50 % effect concentration($72h-EC_{50}$) values of M. acherusicum are pH 7 (0.3 mM), pH 5(1.1 mM) and pH 5.2(1.4 mM), respectively, indicating that M. acherusicum is the most sensitive species. The chronic toxicity test (population growth rate test) on $NO_3{^-}$ of B. plicatilis show that the NOEC, LOEC and $96h-EC_{50}$ are 5.9 mM, 11.8 mM and 32.6 mM, respectively, indicating that B. plicatilis is the most sensitive species. In conclusion, toxic effecst on the marine organism caused by the nitric acid spill accident is determined to be so slightly except for the most adjacent area of the ship in pH scale and such concentration of nitrate, to the extent of directly influencing the survival and reproduction of the marine organism, is determined practically not to be applicable in the typical accidents in the sea.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.12
• /
• pp.4773-4780
• /
• 2014

Background: To investigate the effects of small interference RNA (siRNA) targeting BCR/ABL mRNA on proliferation and apoptosis in the K562 human chronic myeloid leukemia (CML) cell line and to provide a theoretical rationale and experimental evidence for its potential clinical application for anti-CML treatment. Materials and Methods: The gene sequence for BCR/ABL mRNA was found from the GeneBank. The target gene site on the BCR/ABL mRNA were selected according to Max-Planck-Institute (MPI) and rational siRNA design rules, the secondary structure of the candidate targeted mRNA was predicted, the relevant thermodynamic parameters were analyzed, and the targeted gene sequences were compared with BLAST to eliminate any sequences with significant homology. Inhibition of proliferation was evaluated by MTT assay and colony-formation inhibiting test. Apoptosis was determined by flow cytometry (FCM) and the morphology of apoptotic cells was identified by Giemsa-Wright staining. Western blotting was used to analyze the expression of BCR/ABL fusion protein in K562 cells after siRNA treatment. Results: The mRNA local secondary structure calculated by RNA structure software, and the optimal design of specific siRNA were contributed by bioinformatics rules. Five sequences of BCR/ABL siRNAs were designed and synthesized in vitro. Three sequences, siRNA1384, siRNA1276 and siRNA1786, which showed the most effective inhibition of K562 cell growth, were identified among the five candidate siRNAs, with a cell proliferative inhibitory rate nearly 50% after exposure to 12.5nmol/L~50nmol/L siRNA1384 for 24,48 and 72 hours. The 50% inhibitory concentrations ($IC_{50}$) of siRNA1384, siRNA1276 and siRNA1786 for 24hours were 46.6 nmol/L, 59.3 nmol/L and 62.6 nmol/L, respectively, and 65.668 nmol/L, 76.6 nmol/L, 74.4 nmol/L for 72 hours. The colony-formation inhibiting test also indicated that, compared with control, cell growth of siRNA treated group was inhibited. FCM results showed that the rate of cell apoptosis increased 24 hours after transfecting siRNA. The results of annexinV/PI staining indicated that the rate of apoptosis imcreased (1.53%, 15.3%, 64.5%, 57.5% and 21.5%) following treamtne with siRNAs (siRNA34, siRNA372, siRNA1384, siRNA1276 and siRNA1786). Morphological analysis showed td typical morphologic changes of apoptosis such as shrunken, fragmentation nucleus as well as "apoptotic bodies" after K562 cell exposure to siRNA. Western blot analysis showed that BCR/ABL protein was reduced sharply after a single dose of 50nmol/L siRNA transfection. Conclusions: Proliferation of K562 cells was remarkbly inhibited by siRNAs (siRNA1384, siRNA1276 and siRNA1786) in a concentration-dependent manner in vitro, with effective induction of apoptosis at a concentration of 50 nmol/L. One anti-leukemia mechanism in K562 cells appeared that BCR/ABL targeted protein was highly down-regulated. The siRNAs (siRNA1384, siRNA1276 and siRNA1786) may prove valuable in the treatment of CML.