• The Plant Pathology Journal
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• v.24 no.2
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• pp.202-206
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• 2008

Antifungal activity of Korean and Chinese lichen-forming fungi (LFF) was evaluated against plant pathogenic fungus of Colletotrichum acutatum, causal agent of anthracnose on hot pepper. This is the first attempt to evaluate antifungal activity of LFF, instead of lichen thalli, against C. acutatum. Total 100 LFF were isolated from the lichens with discharged spore method or tissue culture method. Among the 100 isolates, 8 LFF showed more than 50% of inhibition rates of mycelial growth of the target pathogen. Especially, Lecanora argentata was highly effective in inhibition of mycelial growth of C. accutatum at the rate of 68%. Antifungal activity of other LFF was in the order of Cetrelia japonica (61.4%), Ramalina conduplicans (59.5%), Umbilicaria esculenta (59.5%), Ramalina litoralis (56.7%), Cetrelia braunsiana (56.5%), Nephromopsis pallescensn (56.1%), and Parmelia simplicior (53.8%). Among the tested LFF, 61 isolates of LFF exhibited moderate antifungal activity against the target pathogen at the inhibition rates from 30 to 50%. Antifungal activity of the LFF against C. acutatum was variable at the species level rather than genus level of LFF. This study suggests that LFF can be served as a promising bioresource to develop novel biofungicides.

• Microbiology and Biotechnology Letters
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• v.9 no.4
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• pp.179-183
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• 1981

An extracellular chitinase was purified from the culture fluid of Streptomyces sp. 115-5, and its inhibition mechanism by end product was studied. The activity of chitinase was suppressed by the reducing sugar as the reaction proceeded, and the activity was inhibited by the addition of D-glucose. Besides D-glucose, the rate of chitin hydrolysis was inhibited by D-glucuronic acid, D-sorbitol and D-xylose in the reaction system of the enzyme. it was found that the hydroxyl groups at the C-2, C-3 and C-4 position of D-glucose molecule play an important role in the inhibition of the chitinase activity. D-glucose was found to inhibit the enzyme activity by mixed type of competitive and non-competitive mode.

• Herbal Formula Science
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• v.9 no.1
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• pp.335-354
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• 2001

This study was designed to investigate biological activity of antler extract added medical plants. The scavenging activity of DPPH radical was low scavenging activity at 0.01% concentration. But in the 0.05% and higher concentration, electron donating ability(EDA) is above 50% except Kongindangagam(48.5%) and significantly good above 70% in the 4 extracts. Superoxide dismutase(SOD)-like activity was 44.3% and 45.1% extracts of Ohjayenjongwhangami and M(market sample), Inhibition of xanthine oxidase were above 50% at 0.5% concentration except Boshingiwhangwhangami and from 62.4% to 84.9% in the 4 extracts. Inhibition rate of boshingiwhangwhangami was hasty increased from 33.5% to 77.5% at 1.0% concentration and others the higher concentration, the more increasing inhibition. Angiotension I-converting enzyme(ACE) inhibitory activities were high activity all of extracts. In the 0.5% concentration, ACE inhibition was above 80%. Especially 0.01% concentration of M was presented 81.8%. The study which conducted to investigate the effect of feeding antler extract group for 50 days on sperm concentration, Ca contents of serum, kidney and femur in rats was higher than that saline group.

• Korean Journal of Medicinal Crop Science
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• v.20 no.5
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• pp.315-319
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• 2012

This study was conducted to select plant growth regulators effective at ginseng berry set inhibition to help root growth in Korean ginseng (Panax ginseng C. A. Meyer). PGRs (ethephon, gibberellic acid, maleic hydrazide, coumarin) were applied to field grown 5-year-old Korean ginseng between one and two times, before and during bloom in 2009, 2010. The number of treatment was more effective in ginseng berry set inhibition when used two times compared with one time in GA 1,000 ppm, MH (5,000, 10,000 ppm), coumarin (5,000, 10,000 ppm) treatment. According to treatment period of plant growth regulator, ginseng berry set inhibition rate from 20days before flowering date to 5days after blooming was the highest in MH 5000 ppm showing 99.9% and the lowest in GA 100 ppm showing 32.8%. The spray treatments of Ethephon (50, 150 ppm) and MH (5,000, 10,000 ppm) from 20 days before the flowering bloom up to 5 days before, and coumarin (5,000, 10,000 ppm) from 20 days to 6 days and before blooming that induced the inhibitory effect more than 90% after 12 weeks. Considering ginseng berry set inhibition characteristics and treatment period ethephon and coumarin was important about applied period but, MH treatment appeared to effective ginseng berry set inhibition regardless of treatment period.

• Microbiology and Biotechnology Letters
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• v.43 no.3
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• pp.187-194
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• 2015

In this study, L. plantarum, when reacting with the culture media of potential pathogenic bacteria, exhibited an increase in growth rate and antimicrobial activity. In order to examine the characteristics and the nature of the reaction with the bacteria, this study carried out experiments involving culturing the test bacteria in M9 minimal media. Subsequently, the supernatant was incrassated by the decompression-drying method. Through colony forming unit assay, it was confirmed that L. plantarum had the function of growth inhibition to various bacteria. After culturing L. plantarum with bacterial media, the growth rate of L. plantarum was measured by absorbance (OD₆₀₀), the results showed that the growth rate (E. coli treatment group: OD₆₀₀ = 0.848, S. typhimurium treatment group: OD₆₀₀ = 0.848) increased, as compared with the non-treated control group (OD₆₀₀ = 0.48). In contrast, the concentrate itself did not induce the growth of L. plantarum. These results were observed as a universal phenomenon of the Lactobacillus species. Moreover, the increase in antimicrobial activity was observed in L. plantarum, which reacted with the culture media of E. coli and S. typhimurium, through a disc diffusion assay, and the result of growth inhibition against various bacteria was induced. Finally, based on the analysis results of the characteristics of bacteria culture media, which increased the growth rate of L. plantarum and antibacterial activity, the bacterial media had a tolerance for catabolic enzymes, pH 2−8 and heat. Therefore, this substance can be said to be a small molecule which is highly stable under various conditions.

• Journal of Korean Society on Water Environment
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• v.20 no.3
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• pp.197-205
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• 2004

Batch test methods have developed for a long time to measure kinetic and stoichiometric parameters which are required to perform steady state design and mathematical modelling of activated sludge processes. However, at various So/Xo ratios, abnormal behaviors of ordinary heterotrophic organism in batch tests have been reported in many researches. Thus, in this research, abnormal behaviors of heterotrophs in batch tests were investigated at various So/Xo conditions by measuring and interpreting oxygen utilization rate. As So/Xo ratio increased, the calculated values of maximum specific growth rates, ${\mu}_{H,max}$ and $K_{MP,max}$, increased. However, at a certain point of So/Xo (around 10mgCOD/mgMLAVSS), ${\mu}_{H,max}$ and $K_{MP,max}$ values started to decrease. According to this observation, three prominent behaviours of heterotrophs were identified at various So/Xo conditions. (1) At low So/Xo region (below 5 mgCOD/mgMLAVSS), the oxygen utilization rate of heterotrophs in batch tests were almost stable and consequently yielded lower maximum specific growth rate. (2) At high So/Xo region (up to 5~10 mgCOD/mgMLAVSS), oxygen utilization rate incresed sharply with time and indicated more upward curvature than the predicted OUR with conventional activated sludge model, which consists of single hetetrotrophs group. Thus, in this region, competition model of two organisms, fast-grower and slow-grower, seemed to be appropriate. (3) At extremely high So/Xo region (over 10mgCOD/mgMLAVSS), significant oxygen utilization rate was still observed even after depletion of readily biodegradable COD. This might be caused by retarded utilization of intermediates which were generated by self inhibition mechanism in the process of RBCOD uptake.

• Research in Plant Disease
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• v.25 no.4
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• pp.179-187
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• 2019

This study was carried out to test the antimicrobial activities of nano metal hybrid materials produced by plasma technologies (radio frequency-thermal plasma system and direct current sputtering system) against microbes isolated from cucurbit (watermelon, pumpkin, and gourd) seeds. Eight different nano metal hybrid materials and four carriers were tested against five different fungal and ten different bacterial isolates in vitro. Among the tested nano metal hybrid material, Brass/CaCO₃ (1,000 ppm) exhibited 100% antimicrobial effect against all the five tested fungi. However, nano metal hybrid material Brass/CaCO₃ (1,000 ppm) inhibited only four bacterial isolates, Weissella sp., Rhodotorula mucilaginosa, Burkholderia sp., and Enterococcus sp. at 100% level, and did not inhibited other six bacterial isolates. Nano metal hybrid material graphite-nickel (G-Ni) showed 100% inhibition rate against Rhizopus stolonifer and 52.94-71.76% inhibition rate against four different fungal isolates. Nano metal hybrid material G-Ni did not show any inhibition effects against tested ten bacterial isolates. In summary, among the tested eight different nano metal hybrid materials and four carriers, Brass/CaCO₃ showed inhibition effects against five fungal isolates and four bacterial isolates, and G-Ni showed variable inhibition effects (52.94-100%) against five fungal isolates and did not show any inhibition effects against all the bacterial isolates.

• Korean Journal of Weed Science
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• v.18 no.4
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• pp.314-324
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• 1998

This study was carried out to investigate the herbicidal action characteristics of EK3143 and EK3150, newly synthesized cyclohexanedione analogues, and their inhibitory effects on the acetyl-CoA carboxylase activity isolated from various plants. Sethoxydim, a typical cyclohexanedione herbicide, had a high herbicidal activity against only grasses with growth inhibition, leaf chlorosis and necrosis. EK3143 and EK3150 had a lower effect against grasses but a higher effect against broadleaf plants such as black nightshade and velvetleaf than sethoxydim had. Low rate application of EK3143 induced leaf bleaching(whitening), while high rate application induced the same symptoms as those of sethoxydim. EK3150 induced more significant whitening, additionally accompanying a curling of meristem part in broadleaf plants. A consistant tendency was observed between the growth inhibition against grasses and the senstivity of grass ACCase to these compounds, but not between herbicidal activities against broadleaf plants and the senstivity of dicotyledonous ACCase; i.e. EK3150, which had higher herbicidal activity against black nightshade and velvetleaf than EK3143 had in greenhouse, rather showed lower ACCase inhibition. In EK3150-treated barnyardgrass, growth inhibition occurred prior to decrease of photosynthetic pigments, in contrast to that of norflurazon and EK3140. These results suggest that EK3143 and EK3150 may have two target sites, ACCase and an unknown site on fatty acid synthesis related to growth inhibition and bleaching respectively, and their symptoms would be appeared in different degree by a differential binding affinity between two action sites.

• Food Science and Preservation
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• v.21 no.1
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• pp.75-81
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• 2014

In this study, the biological activity of water and ethanol extracts from Saururus chinensis by ultra-fine grinding for functional food source are examined. It is more effective to use ethanol than water when extracting phenolic compounds. Approximately 2.5 times higher extraction yield were shown when it was ultra-fine grinded because the particle size decreases, thereby increasing the extraction yield. Normal grinded sample extracts showed 69.8% of DPPH inhibition effect, while fine grinded and ultra-fine grinded sample extracts showed 70.7% and 83.8% each, respectively. Normal extract, as well as fine grinded and ultra-fine grinded extracts, showed over 97% of ABTS inhibition effect, thereby indicating only a slight difference in the anti-oxidative activity with the grinding method. Higher PF was determined with fine grinded and ultra-fine grinded extracts than the normal grinded extract, while ultra-fine grinded 50% ethanol extracts showed the highest anti-oxidative activity value of 1.8 PF. The fine grinded and ultra-fine grinded particle sizes are smaller than the normal grinded particle size, thus increasing the inhibition rate of the TBARS. Furthermore, the ethanol extract was revealed to have a higher effect than the water extracts. The xanthin oxidase inhibition, on the other hand, was identified as ultra-fine grinded that led to the increase in the enzyme inhibition effect. In the angiotensin-converting enzyme, water extracts with normal grinding did not show inhibition activity, while 50% ethanol extracts showed 24% inhibition activity. Moreover, the ethanol extracts showed higher inhibition effect compared to the water extracts. Ultra-fine grinded 50% ethanol extracts showed a slight antibacterial effect on the Staphylococcus aureus and Escherichia coli, while the other extracts showed none. The result suggests that Saururus chinensis extracts by ultra-fine grinding may be more useful than normal grinding as potential sources due to anti-oxidation, angiotensin converting enzyme and xanthine oxidase inhibition.

• KSBB Journal
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• v.9 no.5
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• pp.492-498
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• 1994

A hollow fiber device was utilized to perform a dialysis culture for E. coli. Acetic acid inhibition on the growth of E. coli was relieved by dialyzing the acid from broth into a dialysate reservoir. The rate of acetic acid formation was very sensitive to the concentration of glucose and dissolved oxygen. Therefore it was found that the glucose permeation rate should be balanced with the oxygen supply rate. Specific growth rate of E. coli was determined by the glucose permeation rate through membrane. Under a low permeation rate, acetic acid formation was depressed in accordance with high dissolved oxygen concentration as well as low glucose concentration.