• Microbiology and Biotechnology Letters
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• v.27 no.1
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• pp.8-14
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• 1999

This study was developed to evaluate the growth inhibition effects of cell wall components of Enterococcus faecalis 2B4-1 obtained from feces of neonates against tumor cell lines. Polysaccharide fraction (PS) shown sensitive growth inhibition effect in the cell wall components was isolated and characterized. In growth inhibition effects, residue fractin of whole cell was shown sensitive level of percent survival about 30% when administrated at ehe concentration of 100${\mu}$g/ml, and that was more effective than that of supernatant fraction against the tumor cell lines, SNU-1, 3LL, FARROW and HEC-1-B. Sensitive growth inhibition effects against SNU-1, FARROW and HEC-1-B were performed by whole cell (WC) fraction from Ent. faecalis 2B4-1. Cytoplasm fractin (CP) of WC was shown non-inhibition effect, however, the other part of WC, precipitate of disrupted cell (PD), was sensitive against the tumor cell line mentioned above. Followed by separation to peptidoglycan fraction (PG) and polysaccharide fraction (PS) were all sensitive which the latter was shown more sensitive percent survival than the former. Composed sugars of polysaccharide fraction were determined to D-glucose, L-rhamnose and D-glucosamine, and the rate fo composition was calculated to about 1:1:1 by the data of elemental analysis, IR, TLC and HPLC.

• Journal of Environmental Health Sciences
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• v.41 no.1
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• pp.30-39
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• 2015

Objectives: This study was conducted to determine the heavy metal contents in commercial herbal medicines in Korea. Methods: Monitoring of lead, arsenic, cadmium and mercury was carried out on 116 samples of eleven types of herbal medicines. Among the total samples, 71 samples were domestic and 45 were imported. The samples were digested using the microwave method. The heavy metal contents were measured by inductively coupled plasma atomic emission spectrometry (ICP-AES) and a mercury analyzer. ICP-AES was used to analyze lead, arsenic cadmium. Mercury was analyzed by the amalgamation method. Results: The mean values of the heavy metal contents in the herbal medicines were Pb 0.64mg/kg, As 0.26mg/kg, Cd 0.07mg/kg and Hg 0.004mg/kg. Of the total samples, one violated the MFDS (Ministry of Food and Drug Safety) regulatory guidance on heavy metals in herbal medicines. Lead was detected at more than 5mg/kg in one sample. The measured values of arsenic, cadmium and mercury in the herbal medicines showed levels lower than the recommended levels for herbal medicines in MFDS regulatory guidance. In the comparison of domestic samples with imported herbal medicines, it was found that one domestic sample surpassed the maximum residue limits for lead. Conclusion: These results will be used to establish the regulation and control of heavy metal contents in herbal medicines. In addition, continuous monitoring is needed to ensure confidence in and the safety of these herbal medicines.

• Journal of Microbiology and Biotechnology
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• v.24 no.2
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• pp.160-167
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• 2014

Oligopeptidase B (OpdB) is a serine peptidase widespread among bacteria and protozoa that has emerged as a virulence factor despite its function has not yet been precisely established. By using an OpdB-overexpressing Escherichia coli strain, we found that the overexpressed peptidase makes the bacterial cells specifically less susceptible to several proline-rich antimicrobial peptides known to penetrate into the bacterial cytosol, and that its level of activity directly correlates with the degree of resistance. We established that E. coli OpdB can efficiently hydrolyze in vitro cationic antimicrobial peptides up to 30 residues in length, even though they contained several prolines, shortening them to inactive fragments. Two consecutive basic residues are a preferred cleavage site for the peptidase. In the case of a single basic residue, there is no cleavage if proline residues are present in the $P_1$ and $P_2$ positions. These results also indicate that cytosolic peptidases may cause resistance to antimicrobial peptides that have an intracellular mechanism of action, such as the proline-rich peptides, and may contribute to define the substrate specificity of the E. coli OpdB.

• Journal of Microbiology and Biotechnology
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• v.23 no.10
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• pp.1403-1412
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• 2013

Ethanol fuel production from lignocellulosic biomass is emerging as one of the most important technologies for sustainable development. To use this biomass, it is necessary to circumvent the physical and chemical barriers presented by the cohesive combination of the main biomass components, which hinders the hydrolysis of cellulose and hemicellulose into fermentable sugars. This study evaluated the hydrolytic capacity of enzymes produced by yeasts, isolated from the soils of the Brazilian Cerrado biome (savannah) and the Amazon region, on sugarcane bagasse pre-treated with $H_2SO_4$. Among the 103 and 214 yeast isolates from the Minas Gerais Cerrado and the Amazon regions, 18 (17.47%) and 11 (5.14%) isolates, respectively, were cellulase-producing. Cryptococcus laurentii was prevalent and produced significant ${\beta}$-glucosidase levels, which were higher than the endo- and exoglucanase activities. In natura sugarcane bagasse was pre-treated with 2% $H_2SO_4$ for 30 min at $150^{\circ}C$. Subsequently, the obtained fibrous residue was subjected to hydrolysis using the Cryptococcus laurentii yeast enzyme extract for 72 h. This enzyme extract promoted the conversion of approximately 32% of the cellulose, of which 2.4% was glucose, after the enzymatic hydrolysis reaction, suggesting that C. laurentii is a good ${\beta}$-glucosidase producer. The results presented in this study highlight the importance of isolating microbial strains that produce enzymes of biotechnological interest, given their extensive application in biofuel production.

• Journal of Environmental Science International
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• v.14 no.2
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• pp.121-128
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• 2005

Hexachlorobenzene (HCB) was analyzed in various marine organisms of Korea. HCB was detected in all organism samples with residual concentrations from 0.51 to 222 pg/g wet weight. HCB residue was the highest content in crustacean, and followed by bivalves, fish, cephalopods and gastropods. The residues were comparable to or lower than those in marine organisms of other countries. Daily dietary intake of HCB from seafood was estimated to be 13.4 pg/kg body weight/day. The relative contribution of taxonomic group to the total dietary intake of HCB were in the order of crustaceans $(40.1\%)$, bivalves $(34.2\%)$, fish $(23.1\%)$, cephalopods $(2.22\%)$, and gastropods $(0.38\%)$. Daily dietary intake of HCB expressed as toxic equivalent (TEQ) value was estimated to be $1.34\times10^{-3}pg$ TEQ/kg body weight/day. This value did not exceed tolerable daily intake (TDI) proposed by the WHO, the UK toxicity committee and the KFDA. Cancer risk and target hazard quotient (THQ) due to the consumption of the marine organism in Korean adult population were evaluated using the exposure equation of food ingestion. This result suggests that dietary intake of HCB by the consumption of Korean seafood seems to be safe for human health with negligible cancer and non-cancer risks so far.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.10 no.1
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• pp.11-15
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• 1977

Brownish discoloration develops very rapidly in the storage of dried oyster. This undesirable browning is mainly caused by the series of reactions of sugar-amino condensation, enzymatic oxidation of tyrosine and/or the oxidative rancidity of lipids in the tissue of oyster. Sulfites are commonly used as inhibitors for Maillard type browning reactions in agricultural products. The inhibitory effect of sulfite treatment on canned oysters was also confirmed in some investigations. The results suggested that sulfites not only work on blocking tile amadori rearrangement but also on the reduction of free tyrosine which retards the progress of enzymatic oxidation of tyrosine tyrosinase. In this paper, the effect of sodium sulfite treatment on the reduction of reducing sugar and free tyrosine as a function i)f browning inhibition in oyster was tested and other treatment with glucose-oxidase and yeast were also applied. In preparation of samples, fresh oysters were soaked in sodium sulfite solution by various concentration for different treating times, washed in running water to remove the sulfite residue, and finally dried in the shade. In the result, the treatment of sodium sulfite was certainly effective on the reduction of both free tyrosine and reducing sugars in fresh oyster. The best results were obtained by the treatment of 0.5M sodium sulfite solution for 60 minutes each for soaking and washing. Treatment with, glucose-oxidase and yeast solutions, however, did appear somewhat effective but it required so much time for a certain effect that it seemed not practically applicable.

• Journal of agricultural medicine and community health
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• v.18 no.1
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• pp.55-63
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• 1993

A simultaneous determination method by HPLC for egg-residues sulfamerazine, sulfamethazine, sulfadimethoxine, furazolidone and zoalene was assesed. The drugs were extracted by dechloromethane, The extract after solvent evaporation, is partitioning in hex ane/water and back-partitioning in dechloromethane and analysis by HPLC. The average recovery rates of the above microbials from the egg spiked standard solution were approximately 81.2%, 87.6%, 92.5%. 86.1% and 79.3% respectively. The limit of detection of sulfamerazine. sulfamethazine and sulfamethoxine were in the levels of 0.2ppb, furazolidone and zoalene 0.5ppb respectively. According to this method 84 commercial eggs were examined. Sulfamethanzine was detected at levels of 0.005-0.008ppm in 3 eggs. Sulfadimethoxine was detected at levels of 0.012-0.019ppm in 4 eggs. No sulfamerazine, furazolidone and zoalene was detected in every samples. The residues of antimicrobial agent were safety level as food generally.

• Toxicological Research
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• v.24 no.3
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• pp.207-212
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• 2008

Pesticide residues play several key roles as environmental and food pollutants and it is crucial to develop a method for the rapid determination of pesticide residues in environments. In this study, a simple, effective, and sensitive method has been developed for the quantitative analysis of methoxyfenozide in water and soil when kept under laboratory conditions. The content of methoxyfenozide in water and soil was analyzed by first purifying the compound through liquid-liquid extraction and partitioning followed by florisil gel filtration. Upon the completion of the purification step the residual levels were monitored through high performance liquid chromatography(HPLC) using a UV absorbance detector. The average recoveries of methoxyfenozide from three replicates spiked at two different concentrations and were ranged from 83.5% to 110.3% and from 98.1% to 102.8% in water and soil, respectively. The limits of detection(LODs) and limits of quantitation(LOQs) were 0.004 vs. 0.012 ppm and 0.008 vs. 0.024 ppm, respectively. The method was successfully applied to evaluate the behavioral fate of a 21% wettable powder(WP) methoxyfenozide throughout the course of 14 days. A first-order model was found to accurately fit the dissipation of methoxyfenozide in water with and a $DT_{50}$ value of 3.03 days was calculated from the fit. This result indicates that methoxyfenozide dissipates rapidly and does not accumulate in water.

• The Korean Journal of Community Living Science
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• v.18 no.4
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• pp.699-706
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• 2007

The importance of the standards and its related texts established by Codex Alimentarius Commission (CAC) had been increased by the Agreement of Application of Sanitary and Phytosanitary Measures (SPS Agreement) in World Trade Organization (WTO). To meet the needs of WTO SPS Agreement, biennial CAC meeting had been changed to every year. This study was conducted to analyze the effects on interval between CAC meetings. The years of adoption, revision and amendment of CAC texts were collected from the official standard list and individual texts from CAC homepage. The period since establishment of CAC was divided into four groups by starting negotiation of Uruguay Round, WTO foundation and reducing the interval between CAC meetings. The collected data were analyzed by SPSS program. The numbers of CAC standards, guidelines, recommendations, maximum residue levels, and miscellaneous texts were 202, 56, 46, 3 and 5, respectively. Since 8 documents didn't contain the adoption year, these texts were eliminated to analyze adoption year. For adoption, annually 11.26 texts were established since establishment of CAC and there were no significant difference among the 4 groups. However the average numbers of revisions and amendments of adopted texts for overall periods and for each period were 7.56, 0.93, 6.50, 17.20 and 19.75, respectively. The average numbers of overall decisions, defined as summation of adoption, revision and amendment of texts, for overall periods and for each period were 12.37, 6.27, 9.00, 17.40 and 29.25, respectively. There were significant differences by the WTO foundation and the interval between CAC meetings. The reduced interval of CAC meetings influenced to increase number of revisions and amendments of adopted texts, but not yet adoption of new text.

• Korean Journal of Microbiology
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• v.46 no.4
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• pp.397-400
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• 2010

The activities of mannanase, ${\beta}$-mannosidase, and ${\alpha}$-galactosidase were detected in culture filtrate of Paenibacillus woosongensis showing mannanolytic activity for locust bean gum. Optimal conditions occurred at pH 5.5 and $60^{\circ}C$ for mannanase toward locust bean gum, pH 6.5 and $50^{\circ}C$ for ${\beta}$-mannosidase toward para-nitrophenyl-${\beta}$-D-mannopyranoside, and pH 6.0-6.5 and $50^{\circ}C$ for ${\alpha}$-galactosidase toward para-nitrophenyl-${\alpha}$-D-galactopyranoside in the culture filtrate, respectively. The mannanolytic enzyme of culture filtrate hydrolyzed mannobiose as well as manno-oligosaccharides including mannotriose, mannotetraose, mannopentaose and mannohexaose. It could also hydrolyze ${\alpha}$-1,6 linked galacto-oligosaccharides such as melibiose, raffinose and stachyose to liberate galactose residue. From these results, it is assumed that P. woosongensis produces three enzymes required for the complete decomposition of galactomannan.