• Journal of Aquaculture
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• v.12 no.3
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• pp.167-173
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• 1999

Blocking the 1st mitotic cleavage was performed in mud loach (Misgurmus mizolepis) using UV-irradiated cyprinid loach (M. anguillicaudatus) sperm and ternal shocks Optimum UV range for inactivation of cyprinid loach sperm and thermal shocks. Optimum UV range for inactivation of cyprinid loach sperm was between 3,150 to 4,050 ergs/m$m^2$. Heat shock treatment ($41^{\circ}C$ for 3mins) with various treatment initiation times ranged from 22 to 50 min post insemination resulted wide range of success for induced gynogenesis. Best result was obtained when haploid egges were shocked at 28 min after insemination (corresponding to metaphase division of the 1st cleavage); 26% of total eggs inseminated were viable diploid gynogens. The hatching success and early survival of the both meiotic and mitotic gynogenetic groups were significantly lower than those of control crosses (P<0.05). Maternal origin of induced gynogenetic mud loach was verified by multi-locus DNA fingerprinting.

• Journal of Plant Biology
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• v.33 no.4
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• pp.277-283
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• 1990

Inactivation and reactivation of photosynthetic oxygen evolving complex were studied with isolated spinach (Spinacia oleraceda. L.) photosystem II particles by the activity of oxygen evolution and chlorophyll fluorescence. When the particles were treated with Tris and urea, the oxygen evolution was inactivated and three polypeptides having molecular weights of 33 kDa, 24 kDa and 18 kDa were simultaneously released. But in NaCl-treated particles, two polypeptides of 24 kDa and 18 kDa were removed from PS II particles. The oxygen evolution activities of Tris and urea-treated particles were not restored by adding cation ions (Mg2+, Mn2+ and Ca2+), but the NaCl-treated particles were restored by exogenously added Ca2+. The removal of these extrinsic polypeptides, especially 33 kDa, markedly showed the decrease of the variable fluorescence (Fv). These results are likely to be due to dissipate thermal energy by antenna of photosystem II complexes.

• Korean Journal of Agricultural Science
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• v.26 no.1
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• pp.50-57
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• 1999

The purpose of this study was to determine the thermal inactivation of L. monocytogenes KCTC3443 in liquid culture heated in the controlled microwave system and in the conventional heating method. Furthermore, we have carried out a comparative study on the thermal and nonthermal microwave effects on microorganisms, pasteurized using a controlled microwave energy specially designed apparatuses and a water bath. For the automatic temperature control during microwave heating, the real time data acquisition and computation system is designed with BASIC routine. The automatic temperature control system used in the experiments perform relatively stable control at the experiment temperature of 55, 65, $75^{\circ}C$ and $85^{\circ}C$ for 30 minutes. The effects of microwave heating on liquid cultures was compared with that of conventional heating. The results show that microwave radiation, while being slightly quicker than conventional heating, still reduces effectively the number of pathogenic bacteria during heating for a limit time in liquid cultures. While no particular differences between microwave heating and conventional heating was not observed in the thermal inactivation of L. monocytogenes at 55, 65, $75^{\circ}C$ and $85^{\circ}C$ for 30 min., respectively. Microwave heating is, therefore, substantially not effective in inactivating L. monocytogenes in liquid culture than conventional heating method.

• Journal of Microbiology and Biotechnology
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• v.23 no.6
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• pp.818-825
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• 2013

We isolated and functionally characterized the ${\alpha}$- and ${\beta}$-subunits (ApCpnA and ApCpnB) of a chaperonin from Aeropyrum pernix K1. The constructed vectors pET3d-ApCpnA and pET21a-ApCpnB were transformed into E. coli Rosetta (DE3), BL21 (DE3), or CodonPlus (DE3) cells. The expression of ApCpnA (60.7 kDa) and ApCpnB (61.2 kDa) was confirmed by SDS-PAGE analysis. Recombinant ApCpnA and ApCpnB were purified by heat-shock treatment and anion-exchange chromatography. ApCpnA and ApCpnB were able to hydrolyze not only ATP, but also CTP, GTP, and UTP, albeit with different efficacies. Purified ApCpnA and ApCpnB showed the highest ATPase, CTPase, UTPase, and GTPase activities at $80^{\circ}C$. Furthermore, the addition of ApCpnA and ApCpnB effectively protected citrate synthase (CS) and alcohol dehydrogenase (ADH) from thermal aggregation and inactivation at $43^{\circ}C$ and $50^{\circ}C$, respectively. In particular, the addition of ATP or CTP to ApCpnA and ApCpnB resulted in the most effective prevention of thermal aggregation and inactivation of CS and ADH. The ATPase activity of the two chaperonin subunits was dependent on the salt concentration. Among the ions we examined, potassium ions were the most effective at enhancing the ATP hydrolysis activity of ApCpnA and ApCpnB.

• Korean Journal of Food Science and Technology
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• v.14 no.2
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• pp.125-129
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• 1982

Four peroxidase isozymes from horseradish roots (isozymes A, B, C and D) were isolated by chromatography and were thermally inactivated at $70{\sim}97^{\circ}C$ and pH 7.0. The four isozymes had different inactivation rates and the inactivation of each isozymes did not follow first order kinetics. D values of isozymes A, B, C, D and crude enzyme were 594s, 1850s, 2050s, 78s, 130s and z values were $24.0^{\circ}C$, $12.5^{\circ}C$, $18.0^{\circ}C$, $23.7^{\circ}C$ and $24.0^{\circ}C$, respectively. Sephadex gel chromatogram of the thermally treated isozyme C indicated that the shape and molecular weight of the native isozyme changed during inactivation.

• Journal of Ginseng Research
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• v.13 no.1
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• pp.92-97
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• 1989

This study investigated the effects of high light intensity (100 KLw) and high temperature (45 ℃, dark) on enzyme (glucose-6-phosphate dehydrogenase, acid phosphatase, catalase, peroxidase, and proteinase) activities and characteristics of Panax ginseng C.A. Meyer leaves. Enzyme activity and protein content decreased rapidly under treatment with high light intensity In P ginseng the thermal stabilities of catalase and peroxidase were high (above 70%), and the coagulation rates of soluble proteins were low (below 17%). Therefore, the decrease in enzyme activity and protein content was not caused by increase in leaf temperature due to the high light intensity, but by increase in proteolytic activities. The photochemical formation rate of superoxide radical (O-2) was higher in the P ginseng leaf extracts than in Solanum nigmm, and was accelerated by addition of crude saponin to the buffer extracts.

• Journal of Microbiology and Biotechnology
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• v.29 no.9
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• pp.1401-1411
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• 2019

Mycobacterial cell walls comprise thick and diverse lipids and glycolipids that act as a permeability barrier to antibiotics or other chemical agents. The use of OH radicals from a non-thermal plasma jet (NTPJ) for the inactivation of mycobacteria in aqueous solution was adopted as a novel approach. Addition of water vapor in a nitrogen plasma jet generated OH radicals, which converted to hydrogen peroxide ($H_2O_2$) that inactivated non-pathogenic Mycobacterium smegmatis and pathogenic Mycobacterium tuberculosis H37Rv. A stable plasma plume was obtained from a nitrogen plasma jet with 1.91 W of power, killing Escherichia coli and mycobacteria effectively, whereas addition of catalase decreased the effects of the former. Mycobacteria were more resistant than E. coli to NTPJ treatment. Plasma treatment enhanced intracellular ROS production and upregulation of genes related to ROS stress responses (thiolrelated oxidoreductases, such as SseA and DoxX, and ferric uptake regulator furA). Morphological changes of M. smegmatis and M. tuberculosis H37Rv were observed after 5 min treatment with $N_2+H_2O$ plasma, but not of pre-incubated sample with catalase. This finding indicates that the bactericidal efficacy of NTPJ is related to the toxicity of OH and $H_2O_2$ radicals in cells. Therefore, our study suggests that NTPJ treatment may effectively control pulmonary infections caused by M. tuberculosis and nontuberculous mycobacteria (NTM) such as M. avium or M. abscessus in water.

• Korean Journal of Pharmacognosy
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• v.15 no.2
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• pp.78-84
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• 1984

Polyphenol oxidase was purified from acetone powder extract of the root of Ixeris sonchifolia. The enzyme obtained by ammonium sulfate fractionation and sephadex G-200 gelfiltration gave 51-fold purification over the crude extract. The purified enzyme showed activity toward chlorogenic acid, caffeic acid and pyrocatechol. The kinetics of thermal inactivation of the enzyme followed first-order reaction. Potassium cyanide and cysteine were potent inhibitors.

• The Microorganisms and Industry
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• v.17 no.3
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• pp.86-88
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• 1991

한국의 중부지역을 중심한 11개 지역으로부터 수집한 자료를 재료로 하여 감자바이러스를 분석한 결과 potato virus X, potato virus Y, potato virus S의 3종류의 감자바이러스 계통이 우리나라에 분포하고 있음을 알았다. 이들의 민합감심 비율은 81%를 나타냈으며 강원도 지방이 가장 적었다. 기중 pvx의 제성질을 조사한 결과 dilution end point는 $10^{-6}$ , thermal inactivation point는 7$0^{\circ}C$를 나타냈다. 입자의 크기는 550~650ml사이였다. 기중 600ml이 80%를 갖는 PVX계통이였다.

• Korean Journal of Food Science and Technology
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• v.29 no.2
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• pp.284-291
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• 1997

Microwave vacuum heating method (2450 MHz) was used for a low intensity of heat treatments. High vacuum under the microwave heating could bring low temperature condition. Inactivation of ${\alpha}-amylase,\;{\beta}-amylase$, glucoamylase and peroxidase by microwave vacuum heating were investigated at 60-$80^{\circ}C$. It was compared with conventional heating. The heating condition of microwave vacuum heating was confirmed by the destruction of ascorbic acid. When thermal inactivations of the enzymes by microwave vacuum heating were determined, it was less effective than that of conventional method at the initial stage of heating. It was due to a lag time of microwave heating. However, the heating time for complete inactivation of the enzymes by microwave vacuum heating could be reduced comparing with that of conventional heating. Optimum conditions for inactivation of the enzymes could be obtained by microwave vacuum heating.