• Title/Summary/Keyword: incubation method

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A Study for Antimicrobial Susceptibility of Wetlands to Eliminate Toilet Bacteria

  • LEE, Woo-Sik;KWON, Woo-Taeg
    • Journal of Wellbeing Management and Applied Psychology
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    • v.5 no.3
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    • pp.1-5
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    • 2022
  • Purpose: The purpose of this study is to investigate whether wetland has antimicrobial activity on pathogenic bacteria in the toilet bowl. Research design, data and methodology: Air-dried mud obtained from "Jilmoe Bog" wetland was packed and dissolved in the autoclaved saline. Antimicrobial susceptibility was assessed against three Gram-negative bacteria using disk diffusion method and broth dilution method. Identification of specific bacterium presented in wetland supernatant was performed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Results: Incubation of three Gram-negative bacteria with wetland supernatant inhibited bacterial growth of the bacteria, otherwise increased prevalence of specific bacterium. It was confirmed that Pseudomonas putida was presented in wetland supernatant. Conclusions: The results presented in this study might provide the possibility to utilize wetland supernatant as a bioremediation of toilet bowl bacteria.

Simultaneous Analysis of 17 Organophosphorous Pesticides in Blood by Automated Head Space-SPME GC/MS (HS-SPME-GC/MS에 의한 혈액중 17종 유기인계 농약의 동시분석법)

  • Rhee, Jong-Sook;Jung, Jin-Mi;Lee, Han-Sun;Yeom, Hye-Sun;Lee, Sang-Ki;Park, Yoo-Sin;Chung, Hee-Sun
    • YAKHAK HOEJI
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    • v.54 no.6
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    • pp.429-440
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    • 2010
  • HS-SPME-GC/MS was studied and optimized for the determination of 17 orgarnophosphorous pesiticides (OPPs: chlorpyrifos, chlorpyrifos-methyl, demeton-s-methyl, diazinon, dimethoate, EPN, fenitrothion, fenthion, malathion, methidathion, monocrotophos, parathion, phenthoate, phosphamidon, sulfotep, terbufos, triazophos) in blood. Optimum SPME parameters were selected: choice of SPME fiber (85 ${\mu}m$ polyacrylate), pH effect (0.5 N HCl), salt effect ($Na_2SO_4$, 0.2 g; 20%), headspace incubation temperature ($80^{\circ}C$), headspace incubation time (1 min), headspace adsorption time (30 min) and GC desorption time (2 min). These parameters were optimized using HS-SPME autosampler coupled with gas chromatography-mass spectrometry (GC-MS). Method validation was carried out in terms of linearity, limit of detection (LOD), limit of quantitation (LOQ) and recovery in blood. The assay was linear over 0.5~5.0 mg/l ($r^2$=0.955~1.000). Limit of detection (LOD) and limit of quantitation (LOQ) in blood were determined 0.03~0.3 mg/l (S/N=3) and 0.1~1.1 mg/l (S/N=10), respectively. Relative recovery with 0.5, 1 and 5 mg/l (in blood) were 90.8%, 98.5% and 94.1%, respectively. This method will be applied to the determination of the orgarnophosphorous pesticides in postmortem blood. The proposed protocol can be an attractive alternative to be used in routine toxicological analysis.

Real Time Reverse Transcriptase-PCR to Detect Viable Enterobacteriaceae in Milk

  • Choi, Suk-Ho;Lee, Seung-Bae
    • Food Science of Animal Resources
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    • v.31 no.6
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    • pp.851-857
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    • 2011
  • This study was conducted to develop a real time reverse transcriptase-PCR (RT-PCR) method for the detection of viable Enterobacteriaceae in milk using primers based on the genes of ribosomal proteins S11 and S13 and to determine effects of heating and subsequent treatments on the threshold cycle (Ct) of the real time RT-PCR. Total RNA was isolated from 17 strains of bacteria including 11 strains of Enterobacteriaceae suspended in milk using a modified Tri reagent method. SYBR Green Master Mix was added to the RNA and the mixture was subjected to the real time RT-PCR. The Cts of eleven type strains of the Enterobacteriaceae in milk ($10^7$ cells) in the real time RT-PCR ranged from 21.5 to 24.6. However, the Cts of Pseudomonas fluorescens, Acinetobacter calcoaceticus, and three gram-positive bacteria were more than 40. The real time RT-PCR detected as low as $10^3$ cells in agarose gel electrophoresis. The Cts increased from 22.0 to 34.2 when milk samples contaminated with Escherichia coli ($10^7$ cells/mL) were heated at $65^{\circ}C$ for 30 min. In addition, subsequent incubation at $37^{\circ}C$ for 6 and 24 h increased the Cts further up to 36.2 and 37.2, respectively. Addition of RNase A to the bacterial suspension obtained from the heated milk and subsequent incubation at $37^{\circ}C$ for 1 h increased the Cts to more than 40. The results of this study suggests that pretreatment of bacterial cells heated in milk with RNase A before RNA extraction might enhance the ability to differentiate between viable and dead bacteria using real time RT-PCR.

Study on analysis method of herbicide quizalofop-ethyl (제초제 quizalofop-ethyl 분석법에 관한 연구)

  • Kim, Hee-Kwon;Kim, Byeong-Ho;Shim, Jae-Han;Shu, Yong-Tack
    • Korean Journal of Environmental Agriculture
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    • v.17 no.1
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    • pp.22-25
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    • 1998
  • These studies were conducted to develope analysis method of herbicide quizalofop-ethyl by Gas Liquid Chromatography(GLC) and Enzyme-Linked Immunosoment Assay(ELISA) in soil and plant. Quizalofop produced by hydrolysis of quizalofop-ethyl was conjugated with bovine serum albumin(BSA). Quizalofop antibody was developed in rabbits by using BSA conjugation. Antibody titer, incubation temperature, and incubation time was 32,000, $37^{\circ}C$ and 4hours respectively. Minimum detection limit of quizalofop-ethyl by ELISA was 5ppb. Quizalofop-ethyl recovery from soil by ELISA was more than 95percent. Minimum detection limit of quizalofop-ethyl by GLC was 5ppb. Quizalofop-ethyl recovery from soil by GLC was from 89 percent to 100 percent. Minimun detection limit of quizalofop-ethyl by HPLC was 100ppb. Quizalofop-ethyl recovery from soil by HPLC was 89.6 percent.

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Fibrinolytic Activity and Proteomic Analysis of Bacillus licheniformis HK-12 Isolated from Chungkuk-Jang (청국장에서 분리한 Bacillus licheniformis HK-12의 혈전용해활성과 프로테옴 분석)

  • Sohn, Byung-Hee;Kwon, Sang-Chul;Oh, Kye-Heon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.3
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    • pp.800-806
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    • 2008
  • The strain HK-12 was enriched and isolated from naturally fermented soybean for the production of fibrinolytic enzyme and the proteome of this enzyme induced during the incubation period was analyzed. The activity of fibrinolytic enzyme derived from supernatants of the HK-12 culture was performed by fibrin plate method for solid fibrinolytic activity. As the result, the fibrinolytic activity of HK-12 grown on the nutrient agar media was about 2.3 times greater than that of plasmin used as standard. The purified enzyme was prepared by a series of purification process including ammonium sulfate precipitation, DEAE-cellulose, Sephadex chromatography. The molecular weight of the enzyme was determined to approximately 23kDa with SDS-PAGE. In order to examine which strain HK-12 proteins increased or decreased during the incubation period, 2-DE analysis was performed. Protein spot #1 significantly expressed on the 2-DE gel of bacteria cultivated for 36-hrs was analysed. As the result of protein sequence analysis using MALDI-TOF MS, one protein was identified as serine protein kinase (PrkA).

Changes in CO2 Absorption Efficiency of NaOH Solution Trap with Temperature

  • Park, Se-In;Park, Hyun-Jin;Yang, Hye In;Choi, Woo-Jung
    • Korean Journal of Soil Science and Fertilizer
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    • v.50 no.6
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    • pp.554-561
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    • 2017
  • Under the projected global warming, release of carbon as $CO_2$ through soil organic matter decomposition is expected to increase. Therefore, accurate measurement of $CO_2$ released from soil is crucial in understanding the soil carbon dynamics under increased temperature conditions. Sodium hydroxide (NaOH) traps are frequently used in laboratory soil incubation studies to measure soil respiration rate, but decreasing $CO_2$ gas solubility with increasing temperature may render the reliability of the method questionable. In this study, the influences of increasing temperature on the $CO_2$ capture capacity of NaOH traps were evaluated under $5{\sim}35^{\circ}C$ temperature range at $10^{\circ}C$ interval. Two closed-chamber experiments were performed where NaOH traps were used to capture $CO_2$ either released from acidified $Na_2CO_3$ solution or directly injected into the chamber. The sorption of ambient $CO_2$ within the incubators into NaOH traps was also measured. The amount $CO_2$ captured increased as temperature increased within 2 days of incubation, suggesting that increased diffusion rate of $CO_2$ at higher temperatures led to increases in $CO_2$ captured by the NaOH traps. However, after 2 days, over 95% of $CO_2$ emitted in the emission-absorption experiment was captured regardless of temperature, demonstrating high $CO_2$ absorption efficiency of the NaOH traps. Thus, we conclude that the influence of decreased $CO_2$ solubility by increased temperatures is negligible on the $CO_2$ capture capacity of NaOH traps, supporting that the use of NaOH traps in the study of temperature effect on soil respiration is a valid method.

Effect of Corn Processing Method on Degradability and Fermentation Characteristics in Rumen of Hanwoo (옥수수 가공 방식이 반추위 소화특성에 미치는 영향)

  • Jun Sang Ahn;Dong Hun Kang;Bo Hye Park;Ki Yong Chung
    • Journal of Practical Agriculture & Fisheries Research
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    • v.25 no.4
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    • pp.127-137
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    • 2024
  • This study was conducted to investigate effect of corn flake and corn ground on nutrient digestibility and fermentation characteristics of rumen in Hanwoo. The animals used were three Hanwoo cows implanted with ruminal fistula. Corn were categorized in 2 groups based on the corn processing method: Ground and Flake. The rumen digestibility of dry matter, starch, nitrogen free extract and non fiber carbohydrates were increased in flake compared to ground from 3 to 24 hours of incubation(P<0.05). The pH of rumen was lower in the flaked treatment than ground treatment at 3 hours after incubation, but average pH was no significantly difference between treatments. The average acetic acid, propionic acid and butyric acid were significantly increased in the flaked treatments compared to the ground treatment (P<0.05). Thus, flake processing can improve the carbohydrate availability of corn in the rumen and increase feed value.

Mass Sporulating Method for Conidial Formation of Mycosphaerella nawae Causing the Spotted Leaf Casting of Persimmon (감나무 둥근무늬낙엽병균(Mycosphaerella nawae)의 분생포자 대량 형성법)

  • Kwon, Jin-Hyeuk;Kang, Soo-Woong;Kim, Dong-Kil;Park, Chang-Senk;Kim, Hee-Kyu
    • Korean Journal Plant Pathology
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    • v.13 no.4
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    • pp.255-256
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    • 1997
  • The mass sporulating method for conidia of Mycosphaerella nawac the causal organism of the spotted leaf casting of persimmon was investigated in this experiment. The conidia of M. nawae were sporulated on artificial media after prolonged period of incubation. The maximum amount of conidia of $39.0{\times}10^4/ml$ was harvested from 90-day old culture on PDA at $25^{\circ}C.$

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Immunohistochemical diagnosis of hog cholera with peroxidase-antiperoxidase(PAP) complex method (Peroxidase-antiperoxidase(PAP) 복합체법을 이용한 돼지콜레라의 면역조직화학적 진단)

  • Moon, Oun-gyeong;Cho, Hee-tack;Kim, Soon-bok
    • Korean Journal of Veterinary Research
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    • v.30 no.2
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    • pp.215-221
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    • 1990
  • The present study was intended to use the peroxidase-antiperoxidase method for the identification of hog cholera virus(HCV) in the lymphatic organs of HCV-infected pigs. Sections were incubated with primary antibody (rabbit anti-HCV polyclonal or mouse anti-HCV monoclonal), followed by incubation with linkserum (goat anti-rabbit IgG) in excess and rabbit or mouse PAP complex. The viral antigen was localized mainly in the cytoplasms of lymphoid cells and macrophages. Positive reaction cells were frequently detected in the marginal areas of the germinal centers of the spleens, and also found in the tensils and lymph nodes. The method approved to be highly specific for the identification of the virus and allowed a precise localization of the viral antigen in infected cells.

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Biological Monitoring of Human Exposure to Volatile Halogenated Hydrocarbons Using Urinalysis with Capillary GC-ECD

  • Jung, Won-Tae;Sohn, Dong-Hun
    • Archives of Pharmacal Research
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    • v.15 no.2
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    • pp.109-114
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    • 1992
  • For the risk assessment of human exposure to volatile halogenated hydrocarbons, a dynamic purge trap/on-column cryofocusing method using capillary gas chromatograph-$^{63}Ni$ electron capture detector and thermal desorption unit was applied to analyze the free forms, metabolites of 1, 1, 2-trichloroethylene and 1, 1, 2, 2-tetrachloroethylene. The urine sample was diluted with distilled water, hydrolyzed and sealed. Then the inert gas was infused to purge out free 1, 1, 2-trichloroethylene, free 1, 1, 2, 2-tetrachloroethylene and urichloroethanol. These compounds were trapped to $Tenax^R$ / GC-gas trap device throughout clean up tube. Being undertectable to gas chromatograph directly, trichloroacetic acid was methyl esterificated and trapped in the manner above mentioned. The optimal incubation time to get best recovery of methyl ester was 4 hours at $60^circ$C. The concentrations of free volatile halogenated hydrocarbons and their metabolites in urine were obtained of free volatile halogenated hydrocarbons and their metabolites in urine were obtained from 5 healthy volunteers. This analytical method is expected to make the biological monitoring more precise and convenient.

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