• Journal of Korean Society on Water Environment
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• v.22 no.3
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• pp.482-491
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• 2006

The anaerobic ammonium oxidation (ANAMMOX) from substrates with various $NO_2-N$ and $NH_4-N$ concentationes, which were generated from piggery waste was accomplished by using anaerobic granular sludge as seeding sludge. As the result of operation, when $NO_2-N/NH_4-N$ ratios of ANAMMOX influent were 0.6~1.5, $NO_2-N/NH_4-N$ removal ratios were exhibited 1.19~2.07 (average 1.63). The higher influent $NO_2-N/NH_4-N$ ratios resulted in higher $NO_2-N/NH_4-N$ removal ratios by ANAMMOX. It means that $NO_2-N$ concentration is very important factor in ANAMMOX. Specific ammonium removal rate was constantly as $0.03{\sim}0.04gNH_4-N/g$ VSS-day at $35^{\circ}C$ while it was $0.01gNH_4-N/g$ VSS-day at $20{\sim}30^{\circ}C$. Thus, in order to reduce the effluent N concentration, either an increase of ANAMMOX reactor HRT or more biomass accumulation at the optimal temperature can be considered.

• Journal of Wetlands Research
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• v.21 no.2
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• pp.95-101
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• 2019

In tidal flats that lack plants, methane ($CH_4$) fluxes are both positive (gas emission) and negative (gas "sinking") in nature. The levels of methanotroph populations significantly affect the extent of $CH_4$ sinking. This preliminary study examined $CH_4$ flux in tidal flats using a circular closed-chamber method to understand the effects of macroinvertebrate burrowing activity. The chamber was deployed over decapods (mud shrimp, Laomedia astacina and crab, Macrophthalmus japonicus) burrows for ~ 2 h, and the $CH_4$ and $CO_2$ concentrations were continuously monitored using a closed, diffuse $CH_4/CO_2$ flux meter. We found that Laomedia astacina burrow (which is relatively long) site afforded higher-level $CH_4$ production, likely due to diffusive emission of $CH_4$ in deep-layer sediments. In addition, the large methanotrophic bacteria population found in the burrow wall sediments has $CH_4$ oxidation (consumption) potential. Especially, nitrite-driven anaerobic oxidation of methane (AOM) may occur within burrows. The proposed $CH_4$-oxidation process was supported by the decrease in the ${\delta}^{13}C$ of headspace $CO_2$ during the chamber experiment. Therefore, macroinvertebrate burrows appear to be an important ecosystem environment for controlling atmospheric $CH_4$ over tidal flats.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.1
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• pp.105-110
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• 1985

A incubation study was conducted to find out the effects of rice straw and gypsum as soil ameriolite on urease, nitrate and nitrite reductase activities in newly reclaimed saline sandy soil. The results obtained were summarized as follows: 1. Very low urease activities were observed in saline soil if contrast to high productive paddy soil. Urease activities were lower at 5 days than that of 25 and 50 days after incubation. Remarkably high urease activities were obtained by the application of rice straw and gypsum. 2. Comparing with NPK treatment, application of rice straw and gypsum were enhanced the activities of nitrate and nitraite reductase. 3. Positive correlation (r=0.5501 p=0.05) was obtained between urease activities and ammonium nitrogen concentration in soil. 4. Cyclic oxidation and reduction of nitrate and nitrite in soil were obtained in terms of first order microbial kinetics reaction in case of application of rice straw and gypsum, respectively. 5. Positive correlation (r=0.6296 p=0.05) was obtained between the activitie of nitrite reductase and nitrate reductase in soil.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1187-1193
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• 2010

To elongate the shelf-life of Angelica keiskei and Brassica loeracea var. acephala vegetable juices, UV irradiation was used and the changes of antioxidant activity and nitrite scavenging ability were investigated. The content of polyphenols of vegetable juices were slightly reduced by UV treatment and/or storage period. The DPPH radical-scavenging activities of the vegetable juices treated by UV were higher than that of control but were not changed during storage. However, $ABTS{\cdot}^+$ reducing activities of the vegetable juices were reduced by UV treatment. The $ABTS{\cdot}^+$ reducing activity of Brassica loeracea var. acephala juice was lower when the flow rate was slower. The ferrous ion chelating effects of Angelica keiskei vegetable juices were reduced by UV treatment. In contrast, the ferrous ion chelating effects of Brassica loeracea var. acephala vegetable juices were not different from those of right after manufacturing. The ferrous ion chelating effects on both vegetable juices increased during storage periods. The inhibitory activity of lipid oxidation was decreased slightly by UV treatment on vegetable juices. The nitrite scavenging ability of Angelica keiskei and Brassica loeracea var. acephala vegetable juices treated by UV irradiation was not different from that of control. The nitrate scavenging abilities of vegetable juices in pH 1.2 were higher than those in pH 3.0 and 4.2.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2001.10a
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• pp.421-425
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• 2001

Among the many parameters describing water quality, total nitrogen content(TN) is regarded as important one in relation to water quality management of the waterbodies for its role in eutrophication process. This study evaluated for accuracy, convenience and promptness of nitrogen analysis methods : (1)UV spectrophotometric method, (2)summation method, (3)cadmium reduction method. And, the detection limit of each method was calculated using EPA method. The UV spectrophotometric method after oxidation appears to be more convenient and accurate in determination of the TN contents than the summation method and cadmium reduction method. The summation method is necessary to separate determinations of the organic nitrogen, ammonia, nitrite, and nitrate. And, because summation method has many other methods for each contents, it can be detected for wide range of concentration.

• Journal of Microbiology and Biotechnology
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• v.24 no.11
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• pp.1490-1494
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• 2014

To probe the genomic properties of microbes thriving in desert lakes, we sequenced the full genome of a betaproteobacterial strain (SL110) belonging to the understudied genus Caenimonas of the family Comamonadaceae. This strain was isolated from a freshwater lake in the western Gobi Desert, Northern China. Its genome contains genes encoding carbon monoxide dehydrogenase, nitrate reductase, nitrite reductase, nitric oxide reductase, and sulfur oxidation enzymes, highlighting the potentially important contribution of this group of bacteria to the cycling of inorganic elements in nature. Unexpectedly, a coenzyme $F_{420}$ biosynthesis gene cluster was identified. A further search for $F_{420}$ biosynthesis gene homologs in genomic databases suggests the possible widespread presence of $F_{420}$ biosynthesis gene clusters in proteobacterial genomes.

• Bulletin of the Korean Chemical Society
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• v.22 no.4
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• pp.362-366
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• 2001

To show the effects of metallothionein (MT) on the activity of enzymes involved in the removal of reactive oxygen species, MT has been added to the assay systems of superoxide dismutase (SOD), catalase and peroxidase. We have used assay systems of SOD based on NADPH oxidation and nitrite formation from hydroxylammonium chloride as an assay of superoxide breakdown rate. The two assay systems showed different results at the high concentration of MT. MT showed the scavenging of superoxide in the SOD assay system in the presence and absence of SOD. MT added to the SOD assay system behaved as an activator of SOD, but apo-MT behaved as an inhibitor. When MT was added to the assay system in the presence of a fixed amount of SOD, the breakdown rate of superoxide increased. The effects of MT on the decomposition of hydrogen peroxide and the activity of catalase and peroxidase decomposing hydrogen peroxide were evaluated. MT decreased the activities of catalase and peroxidase. We have concluded that the function of MT as an antioxidant might effect the level of superoxide scavenging and not the level of hydrogen peroxide.

• Food Science of Animal Resources
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• v.38 no.2
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• pp.417-430
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• 2018

This study was conducted to determine the effects of NaCl concentration and cooking temperature on the color and pigment characteristics of presalted ground chicken breasts. Four treatments with different salt concentrations (0%, 1%, 2%, and 3%) were prepared and stored for 7 d prior to cooking. Each sample was cooked to four endpoint temperatures ($70^{\circ}C$, $75^{\circ}C$, $80^{\circ}C$, and $85^{\circ}C$). The salt concentration affected the color and pigment properties of the cooked ground chicken breasts. As the salt concentration increased, the cooking yield and residual nitrite content also increased. However, the samples with 1%, 2%, and 3% NaCl showed similar nitrosyl hemochrome and total pigment contents. Among the products containing salt, the samples with 3% NaCl showed the lowest percentage myoglobin denaturation (PMD) and the lowest CIE $a^*$ values. The cooking temperature had limited effects on the pigment properties of cooked ground chicken breasts. The oxidation-reduction potential and residual nitrite contents increased with cooking temperature, while the PMD, nitrosyl hemochrome, total pigment contents and CIE $a^*$ values were similar in the samples cooked at different temperatures. These results indicated that the addition of up to 2% salt to ground chicken breasts and storage for 7 d could cause the pink color defect of cooked products. However, the addition of 3% NaCl could reduce the redness of the cooked products.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.4
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• pp.414-420
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• 2006

Effluent from an anaerobic digestion system with an elutriated phased treatment(ADEPT, Anaeorbic Digestion Elutriated Phase Treatment) for piggery waste treatment using anaerobic ammonium oxidation(ANAMMOX) process was used as a substrate of partial nitrification reactor. In mesophilic condition($35^{\circ}C$), controlling parameters of nitrite accumulation were HRT, pH, free ammonia(FA) and hydroxylamine rather than dissolved oxygen. Bicarbonate alkalinity consumption ratio including bicarbonate stripping and buffering was 8.78 g $Alk._{comsumed}/g\;NH_4-N_{converted}$. In steady state for 1 day of HRT and $2.7{\sim}4.4mg/L$ of DO, $NO_2-N/NH_4-N$ ratio of partial nitrification effluent was about $1{\sim}3$, which was applicable to ANAMMOX reactor influent for the combined partial nitrification-ANAMMOX process.

• Korean Journal of Food Science and Technology
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• v.35 no.2
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• pp.229-234
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• 2003

Effects of Monascus koji on color, peroxide value, textural properties, microbial stability, and sensory characteristics of bologna-type sausage during storage at $4^{\circ}C$ for 22 days were studied. Addition of 2% Monascus koji resulted in attractive color and distinctly improved color retention. Lipid oxidation was effectively inhibited by lowering the level of peroxide value. Textural properties and microbial stability of the samples were not affected, whereas color was improved by the addition of Monascus koji. Utilization of Monascus koji in meat product could reduce the use of nitrite and inhibit lipid peroxidation during storage.