• Journal of Microbiology and Biotechnology
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• v.32 no.7
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• pp.949-954
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• 2022

The lipolytic yeast Candida aaseri SH14 contains three Acyl-CoA oxidases (ACOXs) which are encoded by the CaAOX2, CaAOX4, and CaAOX5 genes and catalyze the first reaction in the β-oxidation of fatty acids. Here, the respective functions of the three CaAOX isozymes were studied by growth analysis of mutant strains constructed by a combination of three CaAOX mutations in minimal medium containing fatty acid as the sole carbon source. Substrate specificity of the CaAOX isozymes was analyzed using recombinant C. aaseri SH14 strains overexpressing the respective genes. CaAOX2 isozyme showed substrate specificity toward short- and medium-chain fatty acids (C6-C12), while CaAOX5 isozyme preferred long-chain fatty acid longer than C12. CaAOX4 isozyme revealed a preference for a broad substrate spectrum from C6-C16. Although the substrate specificity of CaAOX2 and CaAOX5 covers medium- and long-chain fatty acids, these two isozymes were insufficient for complete β-oxidation of long-chain fatty acids, and therefore CaAOX4 was indispensable.

• Environmental Engineering Research
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• v.11 no.2
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• pp.84-90
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• 2006

UV-catalytic oxidation technique was applied for the treatment of bio-refractory character of the leachate, which is generally present in the form of adsorbable organic halogens (AOX). Destruction of AOX was likely to be governed by pH adjustment, quantitative measurement of oxidants, and the selection of oxidation model type. Peroxide induced degradation ($UV/H_2O_2$) facilitated the chemical oxidation of organic halides in acidic medium, however, the system showed least AOX removal efficiency than the other two systems. Increased dosage of hydrogen peroxide (from 0.5 time to 1.0 time concentration) even did not contribute to a significant increase in the removal rate of AOX. In ozone induced degradation system ($UV/O_3$), alkaline medium (pH 10) favored the removal of AOX and the removal rate was found 11% higher than the rate at pH 3. Since efficiency of the $UV/O_3$ increases with the increase of pH, therefore, more OH-radicals were available for the destruction of organic halides. UV-light with the combination of both ozone and hydrogen peroxide ($UV/H_2O_2$ 0.5 time/$O_3$ 25 mg/min) showed the highest removal rate of AOX and the removal efficiency was found 26% higher than the removal efficiency of $UV/O_3$. The system $UV/H2O_2/O_3$ got the economic preference over the other two systems since lower dose of hydrogen peroxide and relatively shorter reaction time were found enough to get the highest AOX removal rate.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.10
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• pp.1299-1307
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• 2010

This study was conducted to evaluate the effect of dietary antioxidant and energy density on performance and antioxidative status in transition cows. Forty cows were randomly allocated to 4 dietary treatments in a $2{\times}2$ factorial design. High or low energy density diets (1.43 or 1.28 Mcal $NE_L$/kg DM, respectively) were formulated with or without antioxidant (AOX, a dry granular blend of ethoxyquin and tertiary-butylhydroquinone; 0 or 5 g/cow per d). These diets were fed to cows for 21 days pre-partum. During the post-partum period, all cows were fed the same lactation diets, and AOX treatment followed as for the pre-partum period. Feeding a high energy diet depressed the DMI, milk yield, and 4% fat-corrected milk (FCM) of cows. However, AOX inclusion in the diet improved the milk and 4% FCM yields. There was an interaction of energy density by AOX on milk protein, milk fat and total solids contents. Feeding a high energy diet pre-partum increased plasma glucose and ${\beta}$-hydroxybutyrate, whereas dietary AOX decreased plasma ${\beta}$-hydroxybutyrate value during the transition period. There were also interactions between time and treatment for plasma glutathione peroxidase activity and malondialdehyde content during the study. Cows fed high energy diets pre-partum had higher plasma glutathione peroxidase activity 3 days prior to parturition, compared with those on low energy diets. Inclusion of AOX in diets decreased plasma glutathione peroxidase activity in cows 3 and 10 days pre-partum. Addition of AOX significantly decreased malondialdehyde values at calving. Energy density induced marginal changes in fatty acid composition in the erythrocyte membrane 3 days post-partum, while AOX only significantly increased cis-9, trans-11 conjugated linoleic acid composition. The increase in fluidity of the erythrocyte membrane was only observed in the high energy treatment. It is suggested that a diet containing high energy density pre-partum may negatively affect the anti-oxidative status, DMI and subsequent performance. Addition of AOX may improve the anti-oxidative status and reduce plasma ${\beta}$-hydroxybutyrate, eventually resulting in improved lactation performance; the response to AOX addition was more pronounced on the high energy diet.

• Journal of Plant Biotechnology
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• v.48 no.2
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• pp.100-105
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• 2021

Genetic engineering is a potential approach to improve secondary metabolism in plants. In order to elucidate the effect of production of anthocyanin pigment 1 (PAP1) overexpression on the bioactivity of ginseng, we analyzed its antioxidant, antimicrobial, and anti-elastase activities in this study. Our results showed that PAP1 overexpression increased the production of polyphenolic compounds including anthocyanins. The antioxidant, antimicrobial, and anti-elastase activities were stronger in anthocyanin-overproducing ginseng hairy roots (AOX) than in wild ginseng hairy roots. Using a different solvent system (0, 30, 70, and 100% (v/v) EtOH), we revealed that variations in the contents of the polyphenolic compounds were highly correlated with changes in the antioxidant and antimicrobial activities of AOX. The antioxidant, antimicrobial, and anti-elastase effects of AOX highlight genetic engineering as a powerful approach to enhance the therapeutic properties of plants. Our results show that AOX could potentially have various functional applications in the cosmetic and pharmaceutical industries.

• Journal of Life Science
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• v.20 no.2
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• pp.208-212
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• 2010

The low and high temperature stress might affect the yield and quality of many crop species. Alternative oxidase (AOX) gene is known as factors related to stress resistance in plants. In order to develop molecular markers related to stress resistance in Chinese cabbage, fifteen ESTs sharing sequence similarity to arabidopsis AOX genes were found using Brassica rapa EST database from NCBI. The polymorphic DNA sequences using the ESTs were then screened between Chinese cabbage, 'Chiifu' and 'Kenshin'. We found four ESTs that have either insertion or deletion between the two cultivars. These polymorphic sites were then targeted for development of the four PCR based molecular markers. These molecular markers developed in this study could be useful for a test of their relationship with abiotic stress resistance in Chinese cabbage.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.10
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• pp.909-918
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• 2009

As a part of dissolved organic matter, dissolved organic carbon (DOC) or biodegradable DOC (BDOC) fraction in particular is one of important issues in water treatment. Due to role as a nutrient source for bacteria, BDOC, therefore, may cause regrowth problems in water distribution system. The main objectives of this study were to investigate the possibility to minimize the concentration of BDOC in advance water treatment process. DOC in water is fractionized into four fractions such as AnBDOC (adsorbable and non-biodegradable DOC) which possesses adsorption properties but no biodegradation ability; nABDOC (biodegradable and non-adsorbable DOC) which has biodegradation properties but no adsorption ability; ABDOC (adsorbable and biodegradable DOC) which has adsorption properties and biodegradable characteristic; and non-removal DOC (nAnBDOC) which do not have either adsorbability or biodegradability. BAC process was effective for adsorbable DOC (AnBDOC+ABDOC) removal. However, in some cases, the removal ratio of adsorbable DOC was not sufficient. BDOC removal rate is very low or irremovable. Thus, for the control of residual DOC, it is necessary to change the operation condition by BAC process. From the analysis results of DOC fractions, water treatment processes appeared to be effective because it could grasp a remarkable amount of biodegradable, adsorbable and non-removal DOC. The concentration of AOX in non-prechlorination process was reduced from 7.1 ${\mu}g$/L to 0.51 ${\mu}g$/L in BAC process followed by ozonation.

• Journal of Korean Society of Water and Wastewater
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• v.8 no.3
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• pp.9-18
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• 1994

Activated sludge pilot plant testing was conducted to determine the ability of a well-designed activated sludge treatment system to remove chromic toxicity from the bleached kraft pulp mill effluent. Removals of conventional(BOD and SS) and nonconventional(resin and fatty acids, color, AOX) pollutants were estimated. The pilot plant was operated at steady state for about 10 weeks at an F/M of 0.28 and a sludge age of 8.4 days. The average MLSS concentration was 4,309mg/l, of which volatile fraction was 57%. During the operation period, the BOD removal reaction rate(k) was determined to be 8.2/day at $30^{\circ}C$. The BOD removal was 84 percent, which was 3 to 6 percent lower than expected for full-scale treatment. The chronic toxicity of the activated sludge effluent was tested by employing both Dinnel and the BML protocols. It was found that the pilot plant could achieve in excess of 90 percent reduction in chronic echinoderm toxicity. The data show slight reduction of color and AOX across the activated sludge system. The pilot system, however, demonstrated on excellent removal of resin and fatty acids.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.29 no.1
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• pp.52-61
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• 1997

This study was aimed to decrease AOX(Adsorbed Organic Halide Compounds) by applying bleaching methods of A(HNO$_3$ ＋ NaNO$_2$) and $D^{(H/L)}$(dual pH chlorine dioxide bleaching) to conventional OCEDED bleaching stages. And so we investigate the effects of NSA treatment and the influence of production rate of ion species in chlorine dioxide and pulp mixtures according to various pH as well as dual pH on pulp bleaching. Finally the effects of AOC_DED^{(H/L)}ED^{(H/L)}$ bleaching stage were investigated by measuring AOX, brightness, kappa number and viscosity of pulps. A stage was treated by using 4% $HNO_3$ and 0.05~2.0% $NaNO_2$ on pulp and $D^{(H/L)}$ stage was like that pulp mixed with chlorine dioxide solution was adjusted at pH 7.0 and reacted in pulp cosistency 3%, S~20min, $70^{\circ}C$, and then successively for 160~175min at pH 4.0. It was found that suitable $NaNO_2$ addition rate was at 0.6% where the brigtness of pulp was most higher and pulp viscosity was not decreased much. Chlorate ($CIO_3$) was decreased according to pH increase but chlorite($CIO_2$) was highly decreased according to pH increase. And chloride was slightly increased with pH increase. The applying of A and D^{(H/L)}$ bleaching stages to some various multiple bleaching stages ($AOC_DED^{(H/L)}/EopD^{(H/L)} etc.$) had good results that brightness was increased more 2~3% ISO than conventional method(OCEDEopD), but viscosity was dropped by only 1~2cps.

• Journal of Microbiology and Biotechnology
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• v.17 no.5
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• pp.812-821
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• 2007

The ecosystems of certain abandoned mines contain arsenic-resistant bacteria capable of performing detoxification when an ars gene is present in the bacterial genome. The ars gene has already been isolated from Pseudomonas putida and identified as a member of the membrane transport regulatory deoxyribonucleic acid family. The arsenite-oxidizing bacterial strains isolated in the present study were found to grow in the presence of 66.7 mM sodium arsenate($V;\;Na_2HAsO_4{\cdot}7H_2O$), yet experienced inhibited growth when the sodium arsenite($III;\;NaAsO_2$) concentration was higher than 26 mM. Batch experiment results showed that Pseudomonas putida strain OS-5 completely oxidized 1 mM of As(III) to As(V) within 35 h. An arsB gene encoding a membrane transport regulatory protein was observed in arsenite-oxidizing Pseudomonas putida strain OS-5, whereas arsB, arsH, and arrA were detected in strain OS-19, arsD and arsB were isolated from strain RW-18, and arsR, arsD, and arsB were found in E. coli strain OS-80. The leader gene of arsR, -arsD, was observed in a weak acid position. Thus, for bacteria exposed to weak acidity, the ars system may cause changes to the ecosystems of As-contaminated mines. Accordingly, the present results suggest that arsR, arsD, arsAB, arsA, arsB, arsC, arsH, arrA, arrB, aoxA, aoxB, aoxC, aoxD, aroA, and aroB may be useful for arsenite-oxidizing bacteria in abandoned arsenic-contaminated mines.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.4
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• pp.49-57
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• 1999

In CLO2 delignification and bleaching process, formation of chlorate corresponds to a loss of 20-36% of the original CKO2 charge. Because chlorate is inactive and harmful to environmental, it will be of benefit to find methods that can reduce the formation of chlorate during chlorine dioxide bleaching. Chlorate is mainly formed by the reaction HCIO +ClO2 $\longrightarrow$H+ + Cl_ +ClO3-2 On the other hand, AOX in chlorine dioxide bleacing is formed also due to the in-situ produced hypochlorous acid. THus both AOX and chlorate could be reduced by addition of hypochlorous acid. Some paper son the reduction of AOX by additives appeared , but systematic data on chlorate reduction as well as pulp and effluent properties are not available. THus this paper of focused on the effects on the reduction of chlorate and chlorine dioxide bleachability. The additives, fulfamic a챵, AMSO, hydrogen peroxide, oxalic acid were found to eliminate chlorine selectively in chlorine and chlorine dioxide mixture.However, when they were added to bleaching process, sulfamic acid and DMSO showed significant reduction of chlorate formation but hydrogen peroxide and oxalic aicd did not, and significant amount ofhydrogen peroxide was found resided in the bleaching effluent , In addition, sulfamic acid and DMSO decreased the bleaching end ph values while hydrogen peroxide and oxalic acid did not, which also indicated that hydrogen peroxide and oxalic acid were ineffective. The difference might be ascribed to the competitives of hypochlorous acid with lignin, chlorite (CKO2) and additives. Sulfamic acid and DMSO showed better pulpbrightness development but less alkaline extraction efficiency than hydrogen peroxide , oxalic acid and control, which means that insitu hypochlorous acid contributes to the formation of new chromophore structures that can be easily eliminated by alkaline extraction. DMSO decreased the delignification ability of chlorine dioxide due to the elimination of hypochlorous acid, but sfulfamic acid did to because the chlroinated sulfamic acid had stable bleachability. In addition, sulfamic acid, and SMSO shwed decreased color and COD of bleaching effluents, hydrogen peroxide decreased effluent color but not COD content, and oxalic acid had no statistically significant effects. No significant decreases of pulp viocosity were found except for hydrogen peroxide. Based on our results , we suggest that the effectiveness of hydrogen peroxide on the reduction of AOX in literature might be explained by other mechanisms not due to the elimination of hypochlorous acid , but to the direct decomposition of AOX by hydrogen peroxide.