• Food Science and Biotechnology
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• 제14권5호
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• pp.621-627
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• 2005

Halitosis is mainly caused by the presence of volatile sulfur-containing compounds (VSC's) produced by proteolytic periodontopathic bacteria in the oral cavity. Various mouth-rinses have been offered on the market as solutions to reduce halitosis. The aim of this study was to find a potent substance for the prevention of halitosis. The halitosis prevention substance (HPS) from cumin seed powder was purified by solvent extraction, silica gel column chromatography and preparative TLC to yield an oil phase (0.98%). Instrumental analysis such as FT-IR, $^1H$-NMR and $^{13}C$-NMR showed that HPS contained an -OH group, -HC=CH-, -COO-, and long chain acyl group. HPS was therefore determined to be 2-hydroxyethyl-${\beta}$-undecenate. HPS inhibited the growth of Fusobacterium nucleatum and Porphyromonas gingivalis, by 72.44% and 64.37% at $1{\times}10^{-2}\;M$, and by 99.85% and 91.62% at $5\;{\times}\;10^{-2}\;M$, respectively. It also inhibited the activity of L-methionine-${\alpha}$-deamino-${\gamma}$-mercaptomethane-lyase (METase), which was produced by oral microbes. Furthermore, the VSC production by oral microbes in the human mouth air decreased with increasing HPS concentration. These results suggested that HPS from cumin seed is an efficient halitosis prevention agent.

• The Plant Pathology Journal
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• 제20권2호
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• pp.115-126
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• 2004

The actinomycete strain PK-A41 was isolated from a soil sample from pepper fields in Ko-yang, Korea. The strain PK-A41 inhibited the mycelial growth of some plant pathogenic fungi and oomycete, Alternaria mali, Colletotrichum orbiculare, Fusarium oxysporum f.sp. lycopersici, Magnaporthe grisea, Rhizoctonia solani, and Phytophthora capsici. The presence of LL-diaminopi-melic acid in the cell wall extract and the nucleotide sequence of the 16S rDNA region of the strain PK-A41 was assigned to Streptomyces scabiei. Further morpho-logical, biochemical, and pathological analyses also confirmed the strain PK-A41 to be S. scabiei, which is pathogenic to potato tubers. The maximum antibiotic production of the strain PK-A41 was achieved when grown on the glycerol peptone broth (GPB) medium for 9 days.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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• pp.135-135
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• 1998

To find an antagonist of Pythium ultimum, the causal agent of damping-off, numerous actinomycete strains were screened for in vitro inhibiting mycelial growth of the target fungus and producing bioactive metabolites. A strain identified as Streptomyces sp. G60655 was isolated and used for further antagonistic efficacy. The degree of antagonism between the fungus and G60655 was affected by the medium used. Furthermore, the preinoculation of the antagonist was found to be necessary to exhibit the maximum efficacy of antagonsim against the fungus. From the culture broth, a bioactive metabolite was detected and purified by solvent extraction, silica gel chromatography and preparative HPLC. The FAB-MS spectrum of the active compound showed a molecular ion peak at m/z 1101 (M + H)$\^$+/, suggesting the molecular weight of 1100. The UV absorptions at 242 and 323 nm indicated the presence of aromatic functions. The structure of this compound was identified as echinomycin, a depsipeptide antibiotic by spectroscopic studies including various NMR measurements. Echinomycin was inactive against several soil born fungi, but inhibited the mycelial growth of P. ultimum and its related oomycetous fungi.

• Biomolecules & Therapeutics
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• 제9권4호
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• pp.263-269
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• 2001

In this study, we tried to investigate whether poly-L-arginine (PLA) (MW 10,800) significantly affect mucin release from cultured hamster airway goblet cells and the mucosubstances of hypersecretory air-way goblet cells of rats. Confluent primary hamster tracheal surface epithelial (HTSE) cells were metabolically radiolabeled with $^3$H-glucosamine for 24 hr and chased for 30 min in the presence of varying concentrations of PLA to assess the effects on $^3$H-mucin release. Possible cytotoxicities of PLA were assessed by measuring both Lactate Dehydrogenate (LDH) release and by checking the possible changes on the morphology of HTSE cells during treatment. For in vivo experiment, hyperplasia of rat airway goblet cells and increase in intraepithelial mucosubstances were induced by exposing rats to SO$_2$ for 3 weeks and varying concentrations of PLA were administered inhalationally to assess the effects on the mucosubstances of airway goblet cells of rats. The results were as follows : (1) PLA significantly inhibited mucin release from cultured HTSE cells in a dose-dependent manner; (2) there was no significant release of LDH and no significant change on the morphology of cultured HTSE cells during treatment; (3) PLA also affected the intraepithelial mucosubstances of hypersecretory rats and restored them to the levels of control animals. We conclude that PLA inhibit mucin release from airway goblet cells without significant cytotoxicity and possibly normalize the hypersecretion of airway mucosubstances in vivo. This finding suggests that PLA might function as an airway mucoregulative agent.

• 대한수의학회지
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• 제52권3호
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• pp.177-181
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• 2012

Actinobacillus (A.) pleuropneumoniae is the causative agent of pleuropneumonia which is one of the most important respiratory diseases in pigs worldwide. A total of 32 A. pleuropneumoniae isolates from diseased pigs during 2008 to 2010 were serotyped by polymerase chain reaction method. The susceptibility of the isolates to 13 antimicrobial agents were determined by disk diffusion test. In all the 32 isolates examined in this study, serotype 5 (16 isolates: 50%), 1 (7 isolates: 21.9%), 2 (5 isolates: 15.6%) and 12 (1 isolate: 3.1%) were found. Of all tested antimicrobial agents, resistance to oxytetracycline was found in 96.9% of isolates, followed by resistance to amikacin (81.2%), neomycin (68.7%), kanamycin (53.1%), penicillin (50.0%), gentamicin (43.7%), florfenicol (25.0%), ampicillin (18.7%), colistin (9.4%), trimethoprim/sulfamethoxazole, ceftiofur (8.3%), amoxicillin/clavulanic acid (3.1%) and enrofloxacin (0%). Oxytetracycline or florfenicol-resistant isolates were examined for the presence of resistance gene. Among the 31 oxytetracycline-resistant isolates, tetB, tetH and tetO genes were detected in 22 (71%), 8 (26%) and 1 (3%) isolates, respectively. The floR genes were detected in 8 (100%) of the 8 florfenicol-resistant A. pleuropneumoniae isolates.

• 미생물학회지
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• 제31권4호
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• pp.306-311
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• 1993

소수성 기질인 progesterone 을 수용성 반응액 속에 용해하기 위하여 사용되는 methanol 이 Rhizopus nigricans 의 성장과 progesterone 의 11.alpha.-hydroxylation 반응에 미치는 영향을 조사하고, 세포막 인지질의 불포화 지방산 함량을 증가시켜 유기용매에 대한 내성을 유도하였다. R. nigricans 의 균사체는 methanol 존재하에서 형태적인 변화를 일으켰으며, 세포막 인지질의 지방산 조성에 변화를 가져와 불포화 지방산, 특히 oleic acid 의 함량이 증가되었다. 세포의 고정화는 유기용매로부터 세포를 보호하여 progesterone 의 11-.alpha.-hydroxylation 율을 증가시켰다. 성장배지에 500.$\mu$g/l의 biotin 을 첨가하였을 때 세포막 인지질의 oleic acid 함랴이 증가되었으며 methanol 에 대한 내성이 증진되어 높은 progesterone 의 11 $\alpha$-hydroxylation 율을 얻을 수 있었다.

• 한국축산식품학회지
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• 제36권1호
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• pp.100-108
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• 2016

Microbiological contamination of eggs should be prevented in the poultry industry, as poultry is one of the major reservoirs of human Salmonella. ClO₂ gas has been reported to be an effective disinfectant in various industry fields, particularly the food industry. The aims of this study were to evaluate the antimicrobial effect of chlorine dioxide gas on two strains of Salmonella inoculated onto eggshells under various experimental conditions including concentrations, contact time, humidity, and percentage organic matter. As a result, it was shown that chlorine dioxide gas under wet conditions was more effective in inactivating Salmonella Enteritidis and Salmonella Gallinarum compared to that under dry conditions independently of the presence of organic matter (yeast extract). Under wet conditions, a greater than 4 log reduction in bacterial populations was achieved after 30 min of exposure to ClO₂ each at 20 ppm, 40 ppm, and 80 ppm against S. Enteritidis; 40 ppm and 80 ppm against S. Gallinarum. These results suggest that chlorine dioxide gas is an effective agent for controlling Salmonella, the most prevalent contaminant in the egg industry.

• Macromolecular Research
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• 제17권7호
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• pp.476-482
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• 2009

The crystallization behavior of poly(vinyl alcohol) (PVA) in the presence and absence of polypyrrole nanoparticles (PPy NPs) was investigated in terms of the heterogeneous nucleation effect of PPy NPs using FTIR, X-ray diffraction, differential scanning calorimeter and polarized optical microscope analysis. PPy NPs were prepared by dispersion polymerization method stabilized by PVA in aqueous solution. A polymer nanocomposite with uniform dispersity could be readily obtained due to the enhanced compatibility between the filler and matrix. Compared with the PPy NP-absent PVA, the PPy NP/PVA nanocomposite exhibited an enhanced degree of crystallinity. The degree of crystallinity increased up to 17% at the PPy NP concentration of 1 wt%, compared to the pristine PVA. The PPy NP acted as an effective nucleating agent during the crystallization process, thereby enhancing the degree and rate of crystallization. The kinetics study of the crystallization also revealed the decreased value of the Avrami coefficient in the case of the PPy NP/PVA nanocomposite.

• 한방안이비인후피부과학회지
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• 제16권2호
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• pp.96-118
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• 2003

The effect of Glycyrrhizae Radix water extract, known as depigmenting agent, on melanin biosynthesis was investigated in cellular level by using B16 mouse melanoma cells. The inhibitory effect of Glycyrrhizae Radix water extract on melanogenesis was determined by mushroom tyrosinase assay traditionally using in vitro screening test. To determine whether Glycyrrhizae Radix water extract suppress melanin synthesis in cellular level, B16 mouse melanoma cells were cultured in the presence of different concentrations of Glycyrrhizae Radix water extract. Effects on cell proliferation, melanin biosynthesis, tyrosinase activity, DOPAchrome tautomerase activity, and expression level of mRNA for tyrosinase were examined. The maximum concentration of Glycyrrhizae Radix water extract that was not inhibitory to growth of the cells was 2 mgml. At that concentration, melanin synthesis was significantly inhibited without cytotoxicity after 5 days, compared with untreated cells. The treatment with Glycyrrhizae Radix water extract reduced tyrosinase and DOPAchrome tautomerase activity in a dose-dependent manner. However, the treatment with Glycyrrhizae Radix water extract did not affect significantly mRNA levels for tyrosinase. These results suggest that the inhibitory effect of Glycyrrhizae Radix water extract on melanogenesis is correlated with the suppression of tyrosinase and DOPAchrome tautomerase activity more than altering mRNA levels of tyrosinase.

• Corrosion Science and Technology
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• 제3권6호
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• pp.227-232
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• 2004

The carboxylates as a corrosion inhibitor has been studied by many researchers because of its environmental safety and low depletion rate. However, conventional test methods of inhibitor such as weight loss measurements, linear polarization resistance and corrosion potential monitoring etc., evaluate uniform corrosion of metals. These methods are unable to evaluate crevice-related corrosions, which are encountered in most of heat exchanging facilities. In order to choose the optimum corrosion inhibitor, the appropriate test methods are required to evaluate their performances in service environment. From this point of view, polarization technique was used to evaluate the characteristics of sodium heptanoate on corrosion behavior for carbon steel. Especially a thin film crevice sensor technique were applied to simulate the crevice corrosion in this study. From these experiments, we found that oxygen as an oxidizing agent was required to obtain stable passive film on the metal. Presence of oxygen, however, accelerated crevice corrosion. Potential shift by oxygen depletion and weakened inhibitive film inside the crevice were responsible for such accelerated feature. It is shown that film for corrosion inhibition is a mixture of sodium heptanoate and iron (II) heptanoate as reaction product of iron surface and sodium heptanoate. The iron (II) heptanoate which has been synthesized by reaction of heptanoic acid and ferrous chloride in methanol solution forms bidentate complex.