• The Korean Journal of Mycology
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• v.13 no.3
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• pp.169-177
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• 1985

The studies were carried out to obtain the basic data for maximizing the protoplast yields from the mycelia of P. ostreatus and P. sajor-caju. Some factors affecting the regeneration of the protoplast of both species and the productivity of their reversion were also examined. The maximum yields of protoplasts were obtained from four days cultured mycelia of both species on cellophan membrane placed on the surface of PSA or MCM media in a petri dish. The optimal concentration of lytic enzyme Novozym 234 for protoplast releasing was 5 mg per ml of 0.5 M phosphate buffer solution with 0.6 M sucrose or 0.6 M $MgSO_4$ at pH 6.0. The greatest number of protoplasts was released 3 hours after incubation of the mycelia of P. ostreatus and after 4 hours for the P. sajor-caju in the lytic enzyme solution. Among the osmotic stabilizer solutions tested 0.6 M sucrose and 0.6 M KCl showed the best regeneration rates of the protoplasts of both species. When 0.75 % agar solution was over-layed on the regeneration media immediately after inoculation of the protoplast the regeneration rates were greatly enhanced. The ampicillin added to the agar solution prevented bacteria from infection. The reverted isolates produced the sporophores and basidial spores just like their parents without any mutations when they were cultivated in a broad mouth bottle with sawdust substrates.

• Korean Journal of Environmental Agriculture
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• v.34 no.4
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• pp.336-344
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• 2015

BACKGROUND: This study was carried out to collect occurrence data on aluminum in 12 type agricultural products and assess dietary exposure risk to the Korean population health for aluminum concentration in agricultural products.METHODS AND RESULTS: Aluminum analysis samples were performed using microwave device and Inductively Coupled Plasma Optical Emission Spectrometer. The LOD(Limit of Detection) for aluminum was 0.851 μg/kg, while the LOQ(Limit of Quantitation) was 2.838 μg/kg and recovery was 97.6% for aluminum. The average levels of aluminum in mg/kg were 0.526 for rice, 0.546 for Korean cabbage, 1.316 for corn, 6.207 for soybean, 0.549 for sweet potato, 0.257 for potato, 6.963 for spinach, 1.213 for carrot, 0.524 for garlic, 0.950 for radish, 1.015 for leek, and 3.511 for Welsh onion. The dietary exposures of aluminum through usual intake were polished rice 89.31 μg/day, Korean cabbage 33.14 μg/day, corn 0.66 μg/day, soybean 3.72 μg/day, sweet potato 6.86 μg/day, potato 4.96 μg/day, spinach 45.96 μg/day, carrot 6.79 μg/day, garlic 2.36 μ g/day, radish 7.32 μg/day, leek 2.23 μg/day and Welsh onion 43.89 μg/day, taking 0.57%, 0.21%, 0.00%, 0.02%, 0.04%, 0.03%, 0.04%, 0.04%, 0.02%, 0.05%, 0.01% and 0.28% of PTWI(2 mg/kg b.w./week), respectively.CONCLUSION: The levels of overall dietary exposure to aluminum for Korean population through intake of agricultural product was far below the recommended JECFA level, indicating of least possibility of risk.

• Korean Journal of Environmental Agriculture
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• v.30 no.2
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• pp.169-178
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• 2011

BACKGROUND: This study aimed to estimate the measurement uncertainty associated with determination of cadmium and lead from tomato paste by ICP/MS. The sources of measurement uncertainty (i.e. sample weight, final volume, standard weight, purity, molecular weight, working standard solution, calibration curve, recovery and repeatability) in associated with the analysis of cadmium and lead were evaluated. METHODS AND RESULTS: The guide to the expression of uncertainty was used for the GUM (Guide to the expression of Uncertainty in Measurement) and Draft EURACHEM/CITAC (EURACHEM: A network of organization for analytical chemistry in Europe/Co-Operation on International Traceability in Analytical Chemistry) Guide with mathematical calculation and statistical analysis. The uncertainty components were evaluated by either Type A or Type B methods and the combined standard uncertainty were calculated by statistical analysis using several factors. Expected uncertainty of cadmium and lead was $0.106{\pm}0.015$ mg/kg (k=2.09) and $0.302{\pm}0.029$ mg/kg (k=2.16), on basis of 95% confidence of Certified Reference Material (CRM) which was within certification range of $0.112{\pm}0.007$ mg/kg for cadmium (k=2.03) and $0.316{\pm}0.021$ mg/kg for lead (k=2.01), respectively. CONCLUSION(s): The most influential components in the uncertainty of heavy metals analysis were confirmed as recovery, standard calibration curve and standard solution were identified as the most influential components causing uncertainty of heavy metal analysis. Therefore, more careful consideration is required in these steps to reduce uncertainty of heavy metals analysis in tomato paste.

• Journal of Life Science
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• v.22 no.12
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• pp.1672-1679
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• 2012

The effect of high stocking density (HSD) on the expression of stress and lipid metabolism associated genes in the liver of broiler chickens was examined by chicken genome array analysis. The chickens in a control group were randomly assigned to a $495cm^2/bird$ stocking density, whereas the chickens in a HSD group were arranged in a $245cm^2/bird$ stocking density with feeding ad libitum for 35 days. The chickens assigned to the HSD group had a significantly lower body weight, weight gain, and feed intake compared with those of the control group (p<0.05). The mortality of chickens was higher in the HSD group than in the control group. The microarray analysis indicated up-regulation of stress associated genes such as HMGCR, $HSP90{\alpha}$, HSPA5 (GRP78/Bip), DNAJC3 and ATF4, and down-regulation of interferon-${\gamma}$ and PDCD4 genes. The endoplasmic reticulum stress associated genes, HSPA5 (GRP78/Bip), DNAJC3 and ATF4, were highly expressed in the HSD group. The genes, ACSL5, TMEM195 and ELOVL6, involved in fatty acid synthesis, were elevated in the HSD group. The genes, ACAA1, ACOX1, EHHADH, LOC423347 and CPT1A, related to fatty acid oxidation, were also activated in the HSD group. These results suggest that a HSD rearing system stimulates the genes associated with fatty acid synthesis as well as fatty acid oxidation in the liver of broiler chickens.

• Korean Journal of Food Science and Technology
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• v.40 no.2
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• pp.152-159
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• 2008

The purpose of this study was to determine the accurate quantification of vitamin A in infant formula by comparing two different standard stock solutions as well as various sample weights using high performance liquid chromatography. The sources of uncertainty in measurement, such as sample weight, final smaple vloume, and the instrumental results, were identified and used as parameters to determine the combined standard uncertainty based on GUM(guide to the expression of uncertainty in measurement) and the Draft EURACHEM/CITAC Guide. The uncertainty components in measuring were identified as standard weight, purity, molecular weight, dilution of the standard solution, calibration curve, recovery, reproducibility, sample weight, and final sample volume. Each uncertainty component was evaluated for type A and type B and included to calculate the combined uncertainty. The analytical results and combined standard uncertainties of vitamin A according to the two different methods of stock solution preparation were 627 ${\pm}$ 33 ${\mu}$g R.E./100 g for 1,000 mg/L of stock solution, and 627 ${\pm}$ 49 ${\mu}$g R.E./100 g for 100 mg/L of stock solution. The analytical results and combined standard uncertainties of vitamin A according to the various sample weighs were 622 ${\pm}$ 48 ${\mu}$g R.E./100 g, 627 ${\pm}$ 33 ${\mu}$g R.E./100 g, and 491 ${\pm}$ 23 ${\mu}$g R.E./100 g for 1 g, 2 g, and 5 g of sampling, respectively. These data indicate that the preparation method of standard stock solution and the smaple amount were main sources of uncertainty in the analysis results for vitamin A. Preparing 1,000 mg/L of stock solution for standard material sampling rather than 100 mg, and sampling not more than 2 g of infant formula, would be effective for reducing differences in the results as well as uncertainty.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.740-748
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• 2018

This study was conducted to investigate the effects of dietary supplementation of enzyme complex (metalloprotease and xylanase) on growth performance, carcass characteristics and meat storability of broiler chickens. The experiment utilized a 2 (basal and low spec diets) ${\times}$ 3 (0, 0.5 or 1 g/kg of enzyme supplementation) factorial arrangement. A total of 360 male Ross broilers were randomly assigned into the following six groups: BD-T0 (basal diet + enzyme complex 0 g/kg), BD-T1 (basal diet + enzyme complex 0.5 g/kg), BD-T2 (basal diet + enzyme complex 1 g/kg), LD-T0 (low spec diet + enzyme complex 0 g/kg), LD-T1 (low spec diet + enzyme complex 0.5 g/kg), LD-T2 (low spec diet + enzyme complex 1 g/kg). Feed and water were provided ad libitum for 42 days, during which time feed intake and body weight were measured at one-week intervals. After the feeding trial, chickens were slaughtered by exsanguination and samples were collected. Feed intake was lower in the enzyme supplemented groups than the non-supplemented groups (p<0.05), as were body weight and gain (p<0.05). Thus, the feed conversion ratio improved in the enzyme supplemented groups relative to the non-supplemented groups (p<0.05). The carcass rate and production index were also significantly improved by supplementation with enzyme complex (p<0.05). Finally, the thiobarbituric acid reactive substances (TBARS) values were lower in the enzyme supplementation groups after 6 storage days (p<0.05). In conclusion, dietary supplementation with enzyme complex including metalloprotease and xylanase improved growth performance, carcass characteristics, and storability of broiler chicken meat.

• Food Engineering Progress
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• v.21 no.2
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• pp.158-166
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• 2017

Although Semisulcospira libertina is generally regarded as a supplement for the alleviation of alcohol hangover, little is known about its effects on cell metabolism. Therefore, this study was conducted to analyze the constituents of the extracts prepared using different extraction methods and to compare their biochemical properties. The amino acid contents were found to be much higher in acidic and enzymatic hydrolysates than hot water extracts from S. libertina. DPPH radical scavenging activities in acidic and enzymatic hydrolysates were higher than those of hot water extracts. Three types of S. libertina hydrolysate was added to HepG2 cells damaged by acetaminophen (AAP), after which the survival rate of HepG2 cell were measured. In addition, lactate dehydrogenase (LDH) activities in the culture media were evaluated. The survival rates of HepG2 cells were $77.0{\pm}4.3%$ and $81.5{\pm}1.3%$ at 3 h and 5h enzymatic hydrolysates, respectively. These cell survival rates were higher compared to those of the negative control group ($67.8{\pm}4.3%$) treated only with acetaminophen. Cellular toxicities induced by treatment with AAP were also significantly alleviated in response to treatment with the extracts of S. libertina. In addition, the activities of 2 key enzymes that metabolize ethanol, alcohol dehydrogenase and aldehyde dehydrogenase, were upregulated by 4.7- and 2.7-fold respectively in response to treatment with a 3 h enzymatic hydrolysate of S. libertina. Taken together, these results provide biochemical evidence of the method by which S. libertina exerts its biological functions, including the alleviation of alcohol hangover and the protection of liver cells against toxic insults.

• Analytical Science and Technology
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• v.35 no.3
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• pp.136-142
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• 2022

According to media reports, the carcasses of euthanized abandoned dogs were processed at high temperature and pressure to make powder, and then used as feed materials (meat and bone meal), raising the possibility of residuals in the feed of the anesthetic ketamine and dexmedetomidine used for euthanasia. Therefore, a simultaneous analysis method using QuEChERS combined with high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry was developed for rapid residue analysis. The method developed in this study exhibited linearity of 0.999 and higher. Selectivity was evaluated by analyzing blank and spiked samples at the limit of quantification. The MRM chromatograms of blank samples were compared with those of spiked samples with the analyte, and there were no interferences at the respective retention times of ketamine and dexmedetomidine. The detection and quantitation limits of the instrument were 0.6 ㎍/L and 2 ㎍/L, respectively. The limit of quantitation for the method was 10 ㎍/kg. The results of the recovery test on meat and bone meal, meat meal, and pet food showed ketamine in the range of 80.48-98.63 % with less than 5.00 % RSD, and dexmedetomidine in the range of 72.75-93.00 % with less than 4.83 % RSD. As a result of collecting and analyzing six feeds, such as meat and bone meal, prepared at the time the raw material was distributed, 10.8 ㎍/kg of ketamine was detected in one sample of meat and bone meal, while dexmedetomidine was found to have a concentration below the limit of quantitation. It was confirmed that the detected sample was distributed before the safety issue was known, and thereafter, all the meat and bone meal made with the carcasses of euthanized abandoned dogs was recalled and completely discarded. To ensure the safety of the meat and bone meal, 32 samples of the meat and bone meal as well as compound feed were collected, and additional residue investigations were conducted for ketamine and dexmedetomidine. As a result of the analysis, no component was detected. However, through this investigation, it was confirmed that some animal drugs, such as anesthetics, can remain without decomposition even at high temperature and pressure; therefore, there is a need for further investigation of other potentially hazardous substances not controlled in the feed.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.379-387
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• 2013

In order to improve practical utility of agro-microorganisms (AMs) which had been cultured and disseminated to promote plant growth and to control crop diseases, 51 isolates of AMs were collected from 18 agricultural extension centers in local government and screened for multi-functions such as antifungal activity, activities of phosphorus solubilization, IAA and siderophore production, nitrogen fixation, and hydrolytic enzyme activity. Finally we selected one isolate showing good antifungal activity and multi-functions related to plant growth and disease control. The selected isolate, Paenibacillus polymyxa CW, showed good inhibitory effect against plant pathogens, Pyricularia gresea, Colletotrichum acutatum, Fusarium oxysporum, Phomopsis sp., Aspergillus niger, Rhizoctonia solani and Phytophthora capsici. Suppressive effect of P. polymyxa CW against the used plant pathogens except for R. solani was much higher than that of P. polymyxa AC-1 storing in National Academy of Agricultural Science. We found P. polymyxa CW isolate showed good activity in siderophore and IAA formation, and nitrogen fixation. With P. polymyxa CW isolate, siderophore formation activity was similar to that of P. polymyxa AC-1, but IAA formation and nitrogen fixation activity was much higher than that of P. polymyxa AC-1. However neither P. polymyxa CW nor P. polymyxa AC-1 showed hydrolytic enzyme (chitinase, pectinase and cellulase) activity. The treatment of P. polymyxa CW with culture suspension of different cell density ($10^8$, $10^7$. $10^6$ cfu/ml) showed that the highest density reduced incidence of red pepper powdery mildew by 68.3% after 10 days of application. As application density of P. polymyxa CW was decreased, its control efficacy was proportionally decreased. In addition, when P. polymyxa CW was treated to control tomato powdery mildew at the same concentrations and their control effects were investigated after 7 days of inoculation, disease incidence was 0.03, 19.5, 45.7%, respectively, compared to 56.3% that of untreated check. Like red pepper powdery mildew, increase of application density of P. polymyxa CW resulted in increase of its control efficacy proportionally. P. polymyxa CW showed a density-dependent control efficacy against red pepper and tomato powdery mildews. Therefore we think that mode of action of the antagonist for suppressing two powdery mildew diseases might be antibiosis and density of more than $10^8cfu/ml$ was needed to control effectively the two diseases. On this basis, we think that P. polymyxa CW can be a promising control agent for suppressing powdery mildews of red pepper and tomato.

• Journal of Animal Science and Technology
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• v.45 no.2
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• pp.229-240
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• 2003

An in vitro test and a broiler feeding trial were conducted to test the effect of hydrothermal treatment of wheat bran on phytate-P degradation and it’s feeding effect on performance of broilers. Hydrothermal treatment of wheat bran was carried out at 55$^{\circ}C$ with pH 5.5 buffer solution. Phytate-P content of wheat bran decreased quadrically as the wheat bran: buffer solution ratio increased from 1:0.5 to 1:5. Phytate-P degradation was not significantly affected by incubation times above 10 min., drying temperature (55$^{\circ}C$, 65$^{\circ}C$ and 75$^{\circ}C$) or pH of the buffer solution (5.5 and 7.0). A feeding trial was conducted with 240 sex separated d-old broiler chickens (Ross$^{\circledR}$). Broilers were randomly housed to 24 cages of 10 birds each. Six cages (3 of each sex) were assigned to 4 treatments: Control-normal level of non-phytate-P (NPP); LP-low NPP treatment which had 0.1% lower NPP than Control; LPWB-LP with wheat bran which provided 475 IU of plant phytase per kg diet; LPHWB-LP with hydrothermally treated wheat bran. Results of the feeding trial showed that broilers in the LP treatment gained significantly less than other treatments in starter period (1-21d) but only male broilers for growing LP gained significantly less than Control in the grower (22-35d) and overall period. There were no significant differences in weight gain among the birds of LPWB, LPHWB and Control. Feed intake during the overall period was not significantly different between LPWB and Control but that of LP was lower than LPHWB and that of LPHWB was lower than Control. Feed/gain ratio was significantly lower in LPHWB and LP than in Control and LPWP. Mortality was highest in LPHWB. Availability of crude fat, crude ash and Ca was significantly lower in LP than other treatments. Availability of P and Zn was higher in LPWB and LPHWB than in Control and LP. Availability of P, Mg and Zn was highest in LPHWP treatment. Excretion of P was significantly lower in low NPP treatments than in Control. Serum Ca level was highest whereas serum P level was lowest in LP. Tibial crude ash content was higher in wheat bran treatments, but lower in LP than Control. However, tibial Ca content was higher in Control and LP than wheat bran treatments. Tibial P content of LP and LPWB was lower than Control. However, tibial content of Fe was highest in LP. It was concluded that wheat bran, a source of plant phytase, could be used in low NPP broiler diets to prevent the depression of performance. Reduction of P excretion can be achieved concomitantly. Hydrothermal treatment of wheat bran was effective in improving utilizability of some minerals but was not effective in improving performance of broilers.