• Journal of Korean Society of Forest Science
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• v.107 no.1
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• pp.71-80
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• 2018

The effect of $SO_2$ treated pads (Sodium metabisulphate 0, 0.5, 1.0, 2.0 g/kg) on the quality of dried persimmons and dried persimmons slices were investigated. The $SO_2$ treated pads did not affect to weight, moisture loss rate, and soluble solid contents of dried persimmons and dried persimmons slices. The color change (${\Delta}E$) of dried persimmons and dried persimmons slices after storage for 8 weeks were the highest (value=6.0, 6.2) in control, whereas that was the lowest (value=4.8, 4.7) under $SO_2$ pad 2.0 g/kg condition, respectively. When we measured the browning degree of dried persimmons, they showed O.D. 0.65, 0.57, 0.29, and 0.18 in serial dilution treated pads with $SO_2$ pad 0, 0.5, 1.0, and 2.0 g/kg. The browning degree data from aforementioned dried persimmons after 8 weeks was similar to that from dried persimmons slices. The decay rate of dried persimmons and dried persimmons slices after storage for 8 weeks were the highest (value=33.3%, 36.7%) in control, whereas that was the lowest (value=3.3%, 6.7%) under $SO_2$ pad 2.0 g/kg condition, respectively. The concentration of residual $SO_2$ in dried persimmons and dried persimmons slices were detected within a safe range of 15.3~30.0 ppm. Therefore, the shelf-life of dried persimmons and dried persimmons slices were lengthened in $SO_2$ treated pads (especially in $SO_2$ pad 2.0 g/kg) for inhibiting of browning and decay.

• Journal of Soil and Groundwater Environment
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• v.10 no.3
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• pp.38-45
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• 2005

The feasibility of stimulating in situ aerobic cometabolic activity of indigenous microorganisms was investigated in a trichloroethylene (TCE)-contaminated aquifer. A series of single-well natural drift tests (SWNDTs) was conducted by injecting site groundwater amended with a bromide tracer and combinations of toluene, oxygen, nitrate, ethylene and TCE into an existing monitoring well and by sampling the same well over time. Three field tests, Push-pull Transport Test, Drift Biostimulation Test, and Drift Surrogate Activity Test, were performed in sequence. Initial rate of toluene degradation was much faster than the rate of bromide dilution resulting from natural groundwater drift, indicating stimulation of indigenous toluene-oxidizing microorganisms. Transformation of ethylene, a surrogate probing overall activity of TCE transformation, was also observed, and its transformation results in the production of ethylene oxide, suggesting that some tolueneoxidizing microorganisms stimulated may express a orthomonooxygenase enzyme. Also in situ transformation of TCE was confirmed by greater retardation of TCE than bromide after the stimulation of toluene-oxidizing microorganisms. These results indicate that, in this environment, toluene and oxygen additions stimulated the growth and aerobic cometabolic activity of indigenous microorganisms expressing orthomonooxygenase enzymes. The simple, low-cost field test method presented in this study provides an effective method for conducting rapid field assessments and pilot testing of aerobic cometabolism, which has previously hindered application of this technology to groundwater remediation.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.479-485
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• 2005

The 994 throat swabs obtained from 688 adults and 306 children patients with respiratory diseases were examined for Mycoplasma pneumoniae infection by culture method. Antimicrobial susceptibilities of the resulting 123 M. pneumoniae isolates were evaluated by testing minimum inhibitory concentrations (MICs) of erythromycin, minocycline, tetracycline, josamycin, sparfloxacin, ofloxacin, and ciprofloxacin by a broth micro-dilution method. The erythromycin resistant strains of M. pneumoniae was determined above $1.0{\mu}g/ml$ of MIC for erythromycin. The erythromycin resistant strains of M. pneumoniae was confirmed resistant gene mutation of the portions of genes 23S rRNA (domain II and V), and ribosomal protein 14 and L22 by PCR amplified and their nucleotide sequenses were compared to those of the susceptible strain M129. The isolation rate of M. pneumoniae was $12.9\%$ (89/688) for the adults and $11.1\%$ (34/306) for the children. The $MICs_{90}$ of the M. pneumoniae isolates were $0.12{\mu}g/ml$ for minocycline, $0.25{\mu}g/ml$ for sparfloxacin, $0.5{\mu}g/ml$ for ciprofloxacin, ofloxacin, and tetracycline, respectively, and $2.0{\mu}g/ml$ for josamycin and erythromycin, respectively. The isolation rate of erythromycin resistant M. pneumoniae from patients was $49.4\%\;(44/89)$ for the adults, $47.1\%\;(16/34)$ for children, and $48.8\%\;(60/123)$ for the total. No mutation could be detected in the ribosomal protein L22 region, but all strains were mutated in the ribosomal protein L4 as two point mutation M144V. Two point mutations in domain V of 23S rRNA were selected in the presense of erythromycin resistant M. pneumoniae isolates, such as one strain was G2057C mutant, two strains were A2059C mutants, three strains were C2611G mutants, four strains were A2058C mutants, five strains were A2058T mutants, twenty strains were A2059G mutants, and twenty-five strains were A2058G mutants, respectively. These results show that erythromycin was not the most active compound against M. pneumoniae infection in Korea and clinical studies of macrolides in human patients are demanded.

• Analytical Science and Technology
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• v.29 no.4
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• pp.170-178
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• 2016

Accuracy and precision of ID methods for different spike isotopes of ⁷⁶Se, ⁷⁷Se, and ⁷⁸Se were compared for the analysis of Selenium using quadrupole ICP/MS equipped with Octopole reaction cell. From the analysis of Se inorganic standard solution, all of three spikes showed less than 1 % error and 1 % RSD for both short-term (a day) and long-term (several months) periods. They showed similar results with each other and ⁷⁸Se showed was a bit better than ⁷⁶Se and ⁷⁷Se. However, different spikes showed different results when NIST SRM 1568a and SRM 2967 were analyzed because of the several interferences on the m/z measured and calculated. Interferences due to the generation of SeH from ORC was considered as well as As and Br in matrix. The results showed similar accuracy and precisions against SRM 1568a, which has a simple background matrix, for all three spikes and the recovery rate was about 80% with steadiness. The %RSD was a bit higher than inorganic standard (1.8 %, 8.6 %, and 6.3 % for ⁷⁸Se, ⁷⁶Se and ⁷⁷Se, respectively) but low enough to conclude that this experiment is reliable. However, mussel tissue has a complex matrix showed inaccurate results in case of ⁷⁸Se isotope spike (over 100 % RSD). ⁷⁶Se and ⁷⁷Se showd relatively good results of around 98.6 % and 104.2 % recovery rate. The errors were less than 5 % but the precision was a bit higher value of 15 % RSD. This clearly shows that Br interferences are so large that a simple mathematical calibration is not enough for a complex-matrixed sample. In conclusion, all three spikes show similar results when matrix is simple. However, ⁷⁸Se should be avoided when large amount of Br exists in matrix. Either ⁷⁶Se or ⁷⁷Se would provide accurate results.

• The Korean Journal of Mycology
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• v.38 no.1
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• pp.75-79
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• 2010

A total of 25 isolates of Fusarium fujikuroi were obtained from diseased rice plants in Korea from 2006 to 2007 to assess their resistance against fungicides prochloraz and benomyl + thiram. Minimal inhibitory concentration (MIC) values of F. fujikuroi isolates were examined by agar dilution method. Most of the isolates were sensitive to the fungicides. Out of 25 isolates, six were resistant to prochloraz and three to benomyl + thiram. In addition, the isolates CF245, CF249 and CF337 showed resistant to both fungicides. The progenies ($F_1$ isolates) obtained through two different crosses between sensitive parental isolates(CF202, CF232 and CF179) and resistant parental isolate (CF337) were evaluated for their mycelial growth at different temperatures and resistance against fungicides. Mycelial growth rate of $F_1$ isolates originated from CF202 $\times$ CF232 was similar to the parental isolates. However mycelial growth rate of $F_1$ isolates originated from CF179 $\times$ CF337 was faster than their parent isolates. In case of prochloraz, distribution ratio of sensitivity(S) to resistance(R) against to the fungicide of $F_1$ isolates originated from CF202 $\times$ CF232 and CF179 $\times$ CF337 was 86 : 14 and 78 : 22, respectively. In case of benomyl+thiram, all the $F_1$ isolates originated from CF202 $\times$ CF232 were sensitive to the fungicide, however ratio of sensitivity(S) to resistance(R) against to the fungicide of $F_1$ isolates originated from CF179 $\times$ CF337 was 35 : 65.

• Pediatric Infection and Vaccine
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• v.9 no.1
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• pp.79-84
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• 2002

Purpose : About 41% of obtained group A streptococci in the 1998 was reported as erythromycin-resistant streptococci in Seoul, Korea. The most common T serotype was T12, followed by T4 and T28. We'd like to monitor the serological changes and antibiotic sensitivity test of Streptococcus pyogenes obtained from the patients with pharyngotonsillitis and invasive diseases from 1999 through 2001. Also, it could be proposed to choose the proper antibiotic selection in the area where the rate of erythromycin-resistant streptococci is high. Methods : From Jan. 1999 to Oct. 2001, 208 isolates of group A streptococci were collected from inpatients and outpatients with pharyngotonsillitis, scarlet fever, and invasive infections in Seoul and Southern part of peninsula. All isolates were serotyped by T-agglutination, minimum inhibitory concentrations(MICs) which were determined by agar dilution methods, according to the guidelines of the National Committee for Clinical Laboratory Standards (NCCLS). Results : The most common T serotype was T12(29.8%), followed by T1(23.1%), T4 (14.9%). T1 was prominent serotype compared with previous year. T serotyping, among 25 isolates obtained from the patients with scarlet fever in Southern part of peninsula mostly, was T12, T1, and T4 in order of frequency. All the isolates tested were susceptible to penicillin, cefprozil, vancomycin, ceftriaxone, and chloramphenicol. However, 23 isolates(14.2%) was resistant to erythromycin and 18 isolates(11.1%) was resistant to clarithromycin. Serotype T12 was found to be the most resistant serotype to erythromycin and/or clarithromycin. Conclusion : High rate of erythromycin-resistant streptococci which surveyed in 1998 were reduced to 14.2% in this study. We should have to further evaluate the reason of decreased resistant strains and consider the resistant strains of streptococci in choosing the antibiotics. There was no serological characteristics according to the types of disease entities. Between the serologic distributions in Seoul and the Southern part of peninsula area are same, we could presume that the serological typing of strains obtained over the country may be not different.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.931-938
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• 2002

The growth of enterobacteria, Bifidobacterium infantis KCTC 3270, was promoted by natural products bearing antioxidative capacity and mixed combinations of two, three and four kinds of them. B. infantis was expressed a good growth by Aurantii nobilis pericarpium majus L., Astragali radix, Epimedii herba, alone, and two mixed combinations of Epimedii herba and Theae folium, Epimedii herba and Crataegi fructus, Epimedii herba and Eucommiae cortex, and three mixed combinations of Theae folium, Epimedii herba and Chelidonium majus L., Theae folium, Epimedii herba and Aurantii nobilis pericarpium, Theae folium, Chelidonium majus L. and Auantii nobilis pericar pium, Theae folium, Chelidonium majus L. and Astragali radix, Theae folium, Aurantii nobilis pericarpium and puerariae radix, Epimedii herba, Chelidonium majus L. and Aurantii nobilis pericarpium, and four mixed com-binations of Theae folium, Chelidonium majus L., Astragali radix and Epimedii herba, and Theae folium, Chelidonium majus L., Astragali radix and Puerariae readix, and Theae folium, Epimedii herba, Aurantii nobilis pericarpium and Puerariae radix, and Theae folium, Chelidonium majus L., Aurantii nobilis pericarpium and Puerariae radix. The best four mixed combination ofr the growth of B. infantis was Theae folium, Chelidonium majus L. Astragali radix and Epimedii herba, which promoted 2.1 times than that of control, and its antioxidative capacity was also 5 times higher, and the ratio of elimination of hydroxyl radical was more than 80% in each dilution rate. As these combinations of natural products might activate some parts of body, they could be applied to pharmaceutical applications, functional foods, antiaging tea, also expected to promote useful bacterial growth for fermentative beverage bearing multifunction.

• Microbiology and Biotechnology Letters
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• v.30 no.4
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• pp.388-394
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• 2002

The growth of B. bifidum was promoted by natural products bearing antioxidative capacity and mixed combined two, three and four kinds of them. B. bifidum was expressed a good growth by Nelumbo nuclfera gaertner, Corni fructus, Beiamcanda chinensis, alone, and two mixed combinations were composed of Nelumbo nuclfera gaertner and Corni fructus, Nelumbo nuclfera gaertner and Beiamcanda chinensis, Nefumbo nuclfera gaertner and Theae folium, three mixed combinations were oraganized with Nelumbo nuclfera gaertner, Corni fructus and Theae folium, Nelumbo nuclfera gaertner, Corni fructus and Beiamcanda chinensis, Nelumbo nuclfera gaertner, Theae folium and Beiamcanda chinensis, and four mixed combinations were formed with Nelumbo nuclfera gaertner, Theae folium, Beiamcanda chinensis aud Corni fructus, Theae folium, Beiamcanda chinensis, Corni fructus and Glycyrrhizae radix, Nelumbo nuclfera gaertner, Corni fructus, Teae folium and Glycyrrhizae radix, and Nelumbo nuclfera gaertner, Corni fructus, Beiamcanda chinensis and Glycyrrhizae radix. These few mixed combinations promoted cell growth by 2.6 times than that of control, and its antioxidative capacity was also 5.6 times higher, and the ratio of elimination of hydroxyl radical was more than 80% in each dilution rate. As these combinations of natural products could activate some parts of body, they might be applied to pharmaceuitcal applications, functional foods, also expected to multifunctional fermentative beverages.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.2
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• pp.66-75
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• 2012

The objective of this study was to assess the effects of methanogenic bacteria-activated leachate recirculation method for enhancing waste stabilization and landfill gas production from a solid waste landfill. To simulate a conventional landfill (Lys-A), a landfill recirculated only fresh leachate (Lys-B), and two landfills recirculated leachate after pretreating with ASBR (Lys-C and Lys-D), four lysimeters were operated over a period of 4 years. Lys-D was recirculated two times of pretreated leachate volume than that of Lys-C. In the case of the landfill recirculated only fresh leachate and the landfill recirculated leachate after pretreating with ASBR, methane productions were increased until about 600 days, but there were not effect of leachate recirculation for enhancing methane production after about 600 days. It was assumed that leachate recirculation into fewer biodegradable organic wastes had not effect to enhance landfill gas production. Lys-C and Lys-D showed the highest performance for enhancing cumulative methane yield as well as acceleration waste stabilization. In cumulative methane yield, Lys-C (35.51 mL $CH_4/g$ VS) and Lys-D (36.12 mL $CH_4/g$ VS) were much higher than Lys-A (28.37 mL $CH_4/g$ VS) and Lys-B (30.07 mL $CH_4/g$ VS). In case of between Lys-B and Lys-C with the same recirculation rate, COD concentration in Lys-C was more rapidly decreased compared with that in Lys-B. This was attributed to the presence of methanogenic bacteria as well as dilution of inhibitory substances by the methanogenic bacteria-activated leachate recirculation. Therefore, the landfill recirculated leachate after pretreating with ASBR was found to be the most appropriate operating techniques for enhancing waste stabilization and landfill gas production.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.298-304
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• 2010

Nutrient uptake by plants and drainage ratio in culture beds can affect ion balance and concentrations of nutrient solutions in electrical conductivity (EC)-based closed-loop soilless culture. This study was conducted to analyze ion concentration changes with time and drainage ratio under EC-based nutrient control in closed-loop soilless culture for sweet pepper plants (Capsicum annum L. 'Boogie'). At first experiment, ion concentrations of the nutrient solution were periodically analysed while collected drainage was being reused by mixing with fresh nutrient solution at a dilution rate of EC $2.2\;dSm^{-1}$. Changes in ion concentrations of $K^+$, $Ca^{2+}$, $Mg^{2+}$, $NO_3^-$, $SO_4^{2-}$, and $PO_4^{3-}$ were 1.13, 5.35, 0.92, 0.9, 1.10, $0.19\;meq{\cdot}L^{-1}$, respectively. Ion balance such as $K^+$ : $Ca^{2+}$ and $SO_4^{2-}$ : $NO_3^-$ were mainly affected during the recirculation of nutrient solution. At second experiment, ion concentrations and EC of drainage were compared before and after replenishment under different four drainage ratios of 7%, 16%, 39%, and 51%. Ion ratios of the recirculated nutrient solutions such as $K^+$ : $Ca^{2+}$ for cation and $SO_4^{2-}$ : $NO_3^-$ for anion were investigated. ECs of drainage decreased with increase of drainage ratio and each ion concentration showed the same trends as EC did. Ion balances in drainage with drainage ratio were a little different from each other, but each ratio could be corrected by replenishment process. The ion balance at 7% drainage ratio was closest to initial ratio and followed by 16%, 51%, and 39% in the order. Ion balance such as $K^+$ : $Ca^{2+}$ and $NO_3^-$ : $PO_4^{3-}$ were mainly affected the correction process.