• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.4169-4172
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• 2012

To elucidate the roles of cysteine residues in rice Phi-class GST F3, in this study, all three cysteine residues were replaced with alanine by site-directed mutagenesis in order to obtain mutants C22A, C73A and C77A. Three mutant enzymes were expressed in Escherichia coli and purified to electrophoretic homogeneity by affinity chromatography on immobilized GSH. The substitutions of Cys73 and Cys77 residues in OsGSTF3 with alanine did not affect the glutathione conjugation activities, showing non-essentiality of these residues. On the other hand, the substitution of Cys22 residue with alanine resulted in approximately a 60% loss of specific activity toward ethacrynic acid. Moreover, the ${K_m}^{CDNB}$ value of the mutant C22A was approximately 2.2 fold larger than that of the wild type. From these results, the evolutionally conserved cysteine 22 residue seems to participate rather in the structural stability of the active site in OsGSTF3 by stabilizing the electrophilic substrates-binding site's conformation than in the substrate binding directly.

• 한국환경농학회지
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• 제32권2호
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• pp.128-135
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• 2013

BACKGROUND: This study was performed to develop a single residue analytical method for new herbicide metazosulfuron in crops. METHODS AND RESULTS: Brown rice, apple, mandarin, Kimchi cabbage and soybean were selected as representative crops, and clean-up system, partition solvent and extraction solvent were optimized. Instrumental limit of quantitation (ILOQ), linearity of calibration curve and method limit of quantitation (MLOQ) were determined based on the chromatography and whole procedures. For recovery tests, brown rice, apple, mandarin, Kimchi cabbage and soybean samples were macerated and fortified with metazosulfuron standard solution at three levels (MLOQ, 10 MLOQ and 100 MLOQ). And then those were extracted with acetonitrile, concentrated, and partitioned with ethyl acetate. Then the extracts were concentrated again and cleaned-up through $NH_2$ (aminopropyl) SPE cartridge with acetone : dichloromethane (1% acetic acid) (20 : 80, v/v) before concentration and analysis with HPLC. CONCLUSION(S): ILOQ of metazosulfuron was 2 ng (S/N${\geq}$10) and good linearity was achieved between 0.05 and 12.5 mg/Kg of metazosulfuron standard solutions, with coefficients of determination of 0.9999. MLOQ was 0.02 mg/Kg. Good recoveries from 74.1 to 116.9% with coefficients of variation (C.V.) of less than 10% were obtained, regardless of sample type, which satisfies the criteria of Korea Food and Drug Administration (KFDA). Those results were reconfirmed with LC-MS (SIM). The method established in this study is simple, economic and efficient to be applied to most of crops as an official and general method for residue analysis of metazosulfuron.

• Applied Biological Chemistry
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• 제20권2호
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• pp.236-241
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• 1977

carbofuran의 잔류분석방법(殘留分析方法)을 검토(檢討)하고 식물체(植物體)와 토양(土壤)에 처리(處理)한 carbofuran의 잔류량(殘溜量)을 E.C.D.를 사용(使用)한 gas-liquid chromatography로 분석(分析)한 결과(結果)를 요약(要約)하면 다음과 같다. (1) 정제용(精製用) column은 florisil(수분함량(水分含量) 5%)+Alumina(수분함량(水分含量) 4%)+Absorbent mixture를 사용(使用)하는것이 좋은 결과(結果)를 얻었으며 용출액(溶出液)의 처음 30ml 분획(分劃)을 유출(流出)시키는 것이 불순물(不純物) 제거(除去)에 효과적(效果的)이었다. (2) Gelatin capsule을 이용(利用)하여 근부처리(根部處理)한 것이 수도체중(水稻體中)의 잔류량(殘溜量)을 가장 오랫동안 지속(持續)시켰다. (3) 종자처리(種子處理)에 의(依)하여는 종자(種子)와 유묘중(幼苗中)에 침투(侵透)된 carbofuran이 검출(檢出)되지 않았다. (4) 유묘(幼苗)의 침적(浸積)에 의한 carbofuran의 식물체(植物體)의 이행(移行)은 처리농도(處理濃度) 보다 침지시간(浸漬時間)에 비례(比例)하였다. (5) 수도(水稻)에 의한 carbofuran의 흡수량(吸收量)은 근부처리(根部處理)가 수면처리(水面處理)보다 많았고 약효(藥效)도 오래 지속(持續) 되었다. (6) 점토함량(粘土含量)이 많은 토양은 점토함량(粘土含量)이 적은 토양(土壤)보다 carbofuran의 잔류경향(殘留傾向)이 길다. (7) 수확후(收穫後)의 현미중(玄米中)에서는 carbofuran의 잔류량(殘溜量)이 검출(檢出)되지 않았다.

• Applied Biological Chemistry
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• 제8권
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• pp.95-100
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• 1967

수도(水稻) 도열병방제(稻熱病防除)를 위(爲)하여 사용(使用)되는 유기수은제(有機水銀劑)(PMA)에 대(對)해서 우리나라 주요(主要) 수도장려품종(水稻?勵品種)인 팔달(八達)을갖이고 제제(製劑)의 잔류(殘留), 살포시기(撒布時期) 및 살포회수(撒布回數)가 현미중(玄米中)에 잔류(殘留)되는 수은(水銀)의 양적관계(量的關係)를 시험(試驗)하였다. 1. 제제(製劑)의 종류(種類)가 현미(玄米)의 수은잔류(水銀殘留)에 미치는 시험(試驗)을하였던바 엽도열병방제처리(葉稻熱病防除處理)(7 월(月) 13 일(日))에서는 살포용수은유제(撒布用水銀乳劑)(0.216 ppm)는 살분용(撒粉用) 유기수은제(有機水銀劑)(0.16 ppm)보다 높았다. 2. 약제살포시기(藥劑撒布時期)와 수은잔류량관계(水銀殘留量關係)를 보면 유제(乳劑)에 있어서 7 월(月) 13 일(日)에 처리(處理)한 것(0.216 ppm)은 8 월(月) 13 일(日)에 처리(處理)한 (0.304 ppm)보다낮고 분제(粉劑)에 있어서는 7 월(月) 13 일(日)에 처리(處理)한 것(0.16ppm)은 8 월(月) 13 일(日)에 처리(處理)한것(0.238 ppm)보다낮다. 3. 살포회수(撒布回數)가 수은잔류(水銀殘留)에 미치는 영향(影響)을 보면 유제(乳劑)에있어서는 일회살포(一回撒布)(8 월(月) 13 일(日))의 것은 0.304 ppm 이나 이회살포(二回撒布)(7 월(月) 13 일(日) 8 월(月) 13 일(日))의 것은 0.32 ppm 이며 분제(粉劑)에 있어서는 일회사포(一回撒布)(7 월(月) 13 일(日))한 것이 0.238 ppm 이고 이회살포(二回撒布)한 것(7 월(月) 13 일(日), 8 월(月) 13 일(日))은 0.276 ppm 이였다. 4. 수도부위별(水稻部位別) 수은잔류량(水銀殘留量)을 보면 8 월(月) 13 일(日)에 유제(乳劑)를 살포(撒布)한 것은 현미(玄米)에 0.304 ppm, 왕겨에 0.323 ppm 그리고 경엽(莖葉)에는 0.676 ppm, 이 잔류(殘留)되어 있었고 분제(粉劑)를 사용(使用)하였을 때는 현미(玄米)에 0.238 ppm, 왕겨에 0.283 ppm 그리고 경엽(莖葉)에는 0.698 ppm 이 남어있었다. 일반적(一般的)으로 분제(粉劑)는 유제(乳劑)보다 수은잔류량(水銀殘留量)이적고 일회처리(一回處理)한 것은 이회처리(二回處理)한 것보다 잔류량(殘留量)이 낮었다. 7 월(月) 13 일(日에 처리(處理)한 것은 8 월(月) 13 일(日)에 처리(處理)한 것 보다 수은잔류량(水銀殘留量)이 낮다.

• Mycobiology
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• 제45권1호
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• pp.52-56
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• 2017

In this study, we report the manganese peroxidase production ability from a Fusarium sp. strain using an inexpensive medium of agriculture residues of either rice straw or wood chips as carbon source. The highest manganese peroxidase activity on rice straw medium and on wood chips was 1.76 U/mL by day 9 and 1.91 U/mL by day 12, respectively.

• 한국환경농학회지
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• 제38권1호
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• pp.1-9
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• 2019

BACKGROUND: Accurate and simple analytical method determining Fluxametamid residue was necessary in various food matrices. Additionally, fulfilment of the international guideline of Codex (Codex Alimentarius Commission CAC/GL 40) was required for the analytical method. In this study, we developed Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) method to determine the Fluxametamid residue in foods. METHODS AND RESULTS: Fluxametamid was extracted with acetonitrile, partitioned and concentrated with dichloromethane. To remove the interferences, silica SPE cartridge was used before LC-MS/MS (Liquid Chromatography-Tandem Mass Spectrometry) analysis with $C_{18}$ column. Five agricultural commodities (mandarin, potato, soybean, hulled rice, and red pepper) were used as a group representative to verify the method. The liner matrix-matched calibration curves were confirmed with coefficient of determination ($r^2$) greater than 0.99 at calibration range of 0.001-0.25 mg/kg. The limits of detection and quantification were 0.001 and 0.005 mg/kg, respectively. Mean average accuracies were shown to be 82.24-115.27%. The precision was also shown to be less than 10% for all five samples. CONCLUSION: The method investigated in this study was suitable to the Codex guideline for the residue analysis. Thus, this method can be useful for determining the residue in various food matrices as routine analysis.

• 한국환경농학회지
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• 제28권1호
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• pp.53-58
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• 2009

The propose of this study was to find out optimum conditions for no-tillage rice-winter cover crops cropping system. A field research was conducted to evaluate productivity and quality of rice cultivars (Dongjinbyeo and Junambybyeo) in rice-winter cover cropping systems at Doo-ryangmyeon., Sacheon, Gyeongsangnam-do, Korea from January 2005 to October 2006. The experimental soil was Juggog series (fine silty, mesic family of Fluvaquentic Eutrndepts). The rice cultivars were experimented under some different high residue farming systems, i.e. no-tillage no treatment (NTNT), no-tillage amended with rice straw (NTRS), no-tillage amended with rye (NTR), no-tillage amended with Chinese milkvetch (NTCMV), tillage no treatment (TNT), and conventional cropping system (Control). The miss-planted rate was 8.8% in 2005 and range of 10.8% to 13.3% in 2006 at NTR, and the other treatments were carried out at miss-planted rate ranging from 1.2% to 5.0%. Tiller numbers of Junambyeo, and Dongjinbyeo in both of years were the highest in Control, and decreased nearly in NTCMV, NTR, NTRS, NTNT, and TNT in that order. The lowest grain yield was observed in TNT both cultivars due to the lower tiller numbers per area, and spikelet numbers per panicle. Also, no-tillage treatments were lower grain yield than control. On the other hand, 1,000-grain weight was lowest in control due to higher tiller numbers per area, and spikelet numbers per panicle. Ripened grain ratio was a similar aspect in all treatments. The palatability score of milled rice was lowest in control while protein content of milled rice was highest in control. The NTCMV was considered an effective sustainable farming practice for rice yield and quality.

• Journal of Applied Biological Chemistry
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• 제61권2호
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• pp.191-194
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• 2018

국내 주요 식량작물인 벼에서의 잔류성 유기오염물질 잔류평가는 인체 위해성 평가에서 매우 중요하다. 본 연구에서는 과불소화합물 중 perfluorooctanoic acid (PFOA)와 perfluorooctane sulfonic acid (PFOS)의 잔류평가를 벼의 부위별 흡수이행성을 조사하여 수행하였다. 벼는 저농도 오염처리구($1mg\;kg^{-1}$)와 고농도 오염처리구($5mg\;kg^{-1}$)에서 재배 후 현미, 왕겨, 볏짚으로 나누어 잔류량을 조사하였고, 시험결과 현미의 과불소화합물 흡수이행성(0.002-0.006)이 다른 부위에 비해 가장 낮은 것으로 확인되었다. 잔류수준은 볏짚에서 가장 높게 나타났으며, 다음으로 왕겨와 현미 순이었고, 볏짚의 PFOA와 PFOS의 생물농축계수는 최대 1.474와 4.700으로 확인되었다.

• 한국미생물·생명공학회지
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• 제40권4호
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• pp.356-363
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• 2012

The aim of this study was to utilize rice bran, the main waste product of paddy processing, in xanthan gum production by Xanthomonas campestris fermentation. Deffated rice bran was enzymatically hydrolyzed using cellulase, gluco-amylase, alpha-amylase and xylanase at various pHs and temperatures within 0-12 h. The highest sugar content reached at $35^{\circ}C$, pH 5.5 in 6 h with 41.66%. The enzymatic hydrolysate was used as the carbon source for xanthan gum production by X. campestris NRRL B-1459 and X. campestris pv. campestris. The highest productivities obtained were 21.87 and 17.10 g/L, respectively. Viscosity measurement for the obtained xanthan gums and commercial gum was carried out in gum solutions at various pHs and temperatures. The highest viscosity was reached with 1% gum solutions at $20^{\circ}C$ and pH 5.5 for all gums with viscosity values of 470, 131 and 138 mPa sec, respectively. This work has provided relevant scientific information about the use of rice bran, an abundant agroindustrial residue, to produce xanthan gum.

• Mycobiology
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• 제33권3호
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• pp.147-149
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• 2005

The investigation was undertaken to enhance the decomposition process by pre-treatment of rice stubble, having higher concentration of lignin. Air-dried rice stubble was treated with 1.8 liter of 1% NaOH and autoclaved. Six cellulolytic fungi, Trichoderma harzianum, Penicillium citrinum, Curvularia lunata, Aspergillus flavus and Alternaria alternata were grown in basal synthetic medium along with delignified rice-residue as carbon source for production of soluble crude protein. Though the loss of cellulose has been observed by all of them but having a considerable status in the presence of T. harzianum and T. harzianum yielded highest percentage of crude protein (27.99%) with biomass of 375 mg, whereas the lowest protein value (17.91%) was recorded in case of A. niger with biomass of 422 mg. Among the imperfect fungi, T. harzianum was the most potent. Effects of incubation period and nitrogen sources on soluble crude protein production by T. harzianum were also undertaken in this study. Fifth day of incubation period and potassium nitrate as nitrogen source among other nitrogen sources was found most appropriate for soluble crude protein production by the mentioned organism.