• Journal of Ecology and Environment
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• 제41권9호
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• pp.235-245
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• 2017

Background: Loading of excess nutrient via bioremediation of polluted sediment to overlying water could trigger anoxia and eutrophication in coastal area. The aim of this research was to understand the changes of overlying water features such as dissolved oxygen (DO); pH; oxidation reduction potential (ORP); $chlorophyll-{\alpha}$ ($Chl-{\alpha}$); and nitrogen nutrients ammonia ($N-NH_4{^+}$), nitrate ($N-NO_3{^-}$), and nitrite ($N-NO_2^-$) when the sediment was not treated (control) and treated by calcium peroxide for 5 weeks. Methods: The water samples were analyzed for measuring physical and chemical properties along with the sediment analyzed by polymerase chain reaction (PCR) including denaturing gradient gel electrophoresis (DGGE) for identifying the phylogenetic affiliation of microbial communities. Results: Results showed that due to the addition of calcium peroxide in sediment, the overlying water exposed the rise of dissolve oxygen, pH, and ORP than control. Among the nitrogen nutrients, ammonia inhibition was higher in calcium peroxide treatment than control but in case of nitrate inhibition, it was reversed than control. $Chlorophyll-{\alpha}$ was declined in treatment column water by 30% where it was 20% in control column water. Actibacter and Salegentibacter group were detectable in the calcium-peroxide-treated sediment; in contrary, no detectable community ware found in control sediment. Both phylogenetic groups are closely related to marine microflora. Conclusions: This study emphasizes the importance of calcium peroxide as an oxygen release material. Interaction with peroxide proved to be enhancing the formation of microbial community that are beneficial for biodegradation and spontaneity of nutrient attenuation into overlying water.

• 한국식품영양과학회지
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• 제43권8호
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• pp.1289-1295
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• 2014

본 연구에서는 전통발효식품 13종과 천연물 4종에서 27균주를 분리한 후 생육속도가 빠르고 pH 저하 능력이 우수한 3종의 균주를 1차 선발하였으며, 분자생물학적 방법을 이용하여 동정한 결과 Staphylococcus warneri, Sta. epidermidis, Lactobacillus plantarum과 99% 상동성을 보였다. 선발된 3균주의 발효소시지 스타터로서 이용가능성을 알아보기 위해 발효소시지의 환경과 유사한 model-system에서 배양하며 pH 저하 능력, 총산 생성 능력, 생육 능력, 아질산염 소거 능력을 발효소시지의 스타터로 많이 사용되고 있는 5균주 및 상업용 2균주와 비교하였다. Modelsystem에서 pH 저하능과 총산 생성능, 생육능은 관련성이 있었으며, 상업용 균주보다 분리한 Sta. epidermidis DO 10-1, Lac. plantarum MLK 14-2가 우수한 결과를 나타내었다. 아질산염 소거능의 경우에도 분리한 3균주가 상업용 균주보다 상대적으로 빠른 속도를 보였다. 분리한 3균주는 발효소지지 스타터로서의 발효 소거 능력은 우수할 것으로 보이지만 Staphylococcus는 잠재적인 위험성이 제기되는 균주이므로 Lac. plantarum이 발효소지지 제조에 가장 적합할 것으로 사료된다.

• Preventive Nutrition and Food Science
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• 제13권2호
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• pp.77-83
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• 2008

To further the goal of isolating Bacillus sp. from commercial chungkukjang (CKJ) for a development of a probiotic dietary adjunct using soymilk or milk, antioxidant activity of CKJ purchased from the Sunchang Traditional Village in Chunbook province was examined. Six CKJ samples were evaluated and 3 were selected based on the results of the physicochemical analysis and sensory evaluation for further antioxidant study. $IC_{50}$ for DPPH scavenging activity of methanol extracts of CKJ ranged from 238.1 to 345.7 ${\mu}g/mL$. CKJ exhibited over 80% scavenging of ${\cdot}OH$ and ONOO- at concentrations of 100 ${\mu}g/mL$ and 250 ${\mu}g/mL$, respectively. $O_2^-$ and NO scavenging activities of three CKJ were increased in a dose dependent manner with the concentration tested from 100 to 1000 ${\mu}g/mL$. In this study, the methanol extract of CKJ exhibited a great reduction capability and powerful free radical scavenging activity, especially against OH. and ONOO-, which are the most toxic radicals responsible for oxidative damage in the body. However, radical scavenging effects of CKJ on DPPH, $O_2^-$, and nitrite radical were rather moderate. In conclusion, CKJ may reduce the oxidative stress in the body by scavenging the free radicals.

• 자원리싸이클링
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• 제16권6호
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• pp.52-60
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• 2007

탈질 특허분석과 전해기초연구를 통하여 수용액으로부터 질소의 환원제거에 대하여 조사하였다. 세계적으로 수용액으로부터 질소를 제거하는 방법으로 생물학적 기술과 산화환원 기술이 개발되고 있으며, 최근 들어 전해기술에 대한 특허출원도 증가하고 있다. 전해법에서 Fe를 음극으로 Pt를 양극으로 채택한 정전류 전해법에 의하여 1시간동안 총질소를 47% 이상 제거할 수 있었다. 질소함유 폐수를 처리하는 효율적인 방법은 폐수 특성에 맞는 기술의 조합이라고 말할 수 있다. 예를 들어 고농도 질소 함유 폐수를 소량 배출하는 경우 화학적 처리와 전해법의 조합으로 질산성 질소를 아질산성 질소로 일차 전환시켜 전해효율을 극대화시키면서 2차 오염원인 용해 금속이온을 전해과정에서 음극에 환원 회수하는 방법 등이 실용화에 유리하다고 말할 수 있다.

• Archives of Pharmacal Research
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• 제20권3호
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• pp.259-263
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• 1997

In the preparation of acyclic thymidine nucleoside analogues, $K_2CO_3$(or NaH) treated thymine in DMSO was alkylated with .omega.-chloroalkyl nitrite (Cl-(CH_2)n-CN; n=1, 2, 3, 4) to provide an isomeric mixture of 1-(${\omega}$-cyanoalkyl)thymine (2a-d) and 1,3-bis(${\omega}$-cyanoalkyl)thymine in approximately 5:1 ratios. Reduction of the cyano function 2a-d with $NaBH_{4}/CoCl_{2}$ center dot$ 6H_{2}O$gave the corresponding 1-(${\omega}$aminoalkyl)thymine (3a-d). The newly formed primary amino function in 3a-d was directly reacted with 2-chloroethylisocyanate to afford the 1-[.omega.($N^{I}$-2-chloroethylureido) alkyl]thymine (4a-d) in good yields. Nitrosation of 1-[5-($ N^{I}-2$-chloroethylureido)pentyl] thymine (4d) with glacial acetic acid and dry $NaNO_{2}$-powder in anhydrous $CH_{2}Cl_{2}$gave two types of regioisomeric nitrosoureas, 1-[5-($N^{I}$--chloroethyl-$N^{I}$--nitrosoureido)pentylithymine (5d) and 1-[5-($N^{I}-2$-chloroethyl-N-nitrosoureido)pentyllthymine in approximately 5 :1 ratios. The in vitro cytotoxicity of the synthesized compounds (2a-d, 3a-d, 4a-d and 5a-d) against three cell lines (K-562, P-388 and FM-3A) are measured as $IC^{50}$ values. Compounds 3b and 4c showed moderate activities against all three cell lines, and all other compounds were found to be not active.

• 한국수산과학회지
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• 제54권5호
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• pp.751-760
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• 2021

This study investigated the changes in water quality parameters and microbial colonies when ozone was applied to a semi-recirculating aquaculture system (semi-RAS) for the olive flounder Paralichthys olivaceus (500 g in average weight). Concentrations of ozone-produced oxidants (OPO) in rearing tanks were maintained at 0, 0.014, 0.025 mg/L as Cl₂ for 26 days. Except total ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, phosphate phosphorus, chemical oxygen demand, and total suspended solids decreased significantly with increasing OPO concentration in daily and weekly monitoring (P<0.05). Colony forming unit (CFU) counts of heterotrophic marine bacteria decreased in an OPO concentration-dependent manner. Overall reduction rates of microbial colonies in the treatments were 80% higher than those of the control (P<0.05). During the experiment, the OPO concentration-driven ozonation was reliably practiced without any adverse effects on the animals cultured in semi-RAS. Considering the biohazard, operating cost, and stability of ozonation, an OPO concentration of 0.014 mg/L would be sufficient to control water quality parameters and microbial colonies in a semi-RAS.

• 산업식품공학
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• 제14권3호
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• pp.263-270
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• 2010

Xylanase를 생산하는 호알칼리성 균주를 토양으로부터 분리하여 동정하였다. 토양으로부터 분리한 호알칼리성 균주 3000여종 중 xylanase 활성이 가장 높은 균주인 strain DK-2386 균주를 선별하였다. Gram 염색과 SEM을 통한 형태학적 특성을 관찰하였으며, Methods for General and Molecular Bacteriology와 Bergey's manual of systematic bacteriology, 그리고 Biochemical tests for identification of medical bacteria에 준하여 생화학적 특성을 확인한 결과 배양액의 색은 붉은 빛을 나타내었으며, Gram양성 간균, 내생포자형성, catalase 양성, oxidase 양성, 혐기성 양성, glucose로부터 gas 형성 양성, casein 가수분해 양성, starch 가수분해 양성, CMC 가수분해 양성, xylan 가수분해 양성, nitrate 환원능 양성이며 10% NaCl 농도에서도 생육하는 것을 확인하였다. 균체의 지방산 조성 분석 결과 $C_{15:0\;ISO}$ 27.35%와 $C_{15:0\;ANTEISO}$ 31.54%, $C_{16:0}$ 9.70%로 이루어져 Bacillus속으로 동정되었으며, 16S rDNA 염기서열 분석결과 B. agaradhaerens와 100%의 유사성을 갖는 것을 확인하였다. (사)한국종균협회로부터 분양받은 Bacillus agaradhaerens 40952, B. alcalophilus와 strain DK-2386 균주사이의 생화학적 특성을 비교한 결과 B. agaradhaerens와 속과 종이 같으나 미세하게 특성이 다른 균주로 판단되어 B. agarad haerens DK-2386이라 명명하였다.

• 한국환경과학회지
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• 제28권1호
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• pp.1-6
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• 2019

Ptecticus tenebriferwas incorporated to partially or totally replace the diets of juvenile white shrimp (Litopenaeus vannamei). Experimental groups of shrimp with an average initial body weight of $0.014{\pm}0.001g$ were fed each of the 5 diets formulated to include 0, 25, 50, 75, and 100% (C, T25, T50, T75, and T100, respectively) of Ptecticus tenebriferpowder substituted for commercial feed. After eight weeks of feeding trials, juvenile shrimp fed with diets T25 and T50 showed higher live weight gain ($2.298{\pm}0.405$ and $2.539{\pm}0.406$, respectively), and a better feed conversion ratio ($1.389{\pm}0.246$ and $1.536{\pm}0.246$, respectively) compared to those of shrimp fed a control diet. Survival rate was 98% in all experimental groups except for the T75 group ($66.67{\pm}57.73%$ survival). The levels of immune markers such as beta-glucan binding protein, prophenoloxidase, and crustin associated with the cellular and humoral immunity of shrimp were found to be higher in 25% and 50% commercial feed replacement groups. A reduction in total nitrogen, nitrite nitrogen, and ammonia levels was greater in T25 and T50 rather than in T75 and T100. These results clearly indicate that replacement of feed with 25 to 50% Ptecticus tenebriferpowder in juvenile white shrimp diet was optimal in promoting the growth performance of shrimp without any adverse effects.

• 대한방사성의약품학회지
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• 제4권2호
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• pp.80-84
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• 2018

$[^{13}N]$Ammonia or $[^{13}N]NH_3$ is one of the most widely used PET tracer for the measurement of MBF. To produce $[^{13}N]NH_3$, devarda's alloy which contains aluminum, copper and zinc is used for the purpose of reduction from $^{13}N$-nitrate/nitrite to $[^{13}N]NH_3$. Since aluminum has neurotoxicity and renal toxicity, the amount of it should be carefully limited for the administration to the human body. Although USP and EP provide a way to identify the aluminum ion concentration, there are some difficulties to perform. Therefore, we tried to develop the modified method for verifying aluminum concentration of test solution. We compared color between test and standard solutions using chrome azurol S in pH 4.6 acetate buffer. We also tested color change of test and standard solutions according to pH, amounts and the order of reagent and time difference These results demonstrated that the color change of the solution can reflect quantitatively measure aluminum ion concentration. We hope the method is to be used effectively and practically in many sites where $[^{13}N]NH_3$ is produced.

• 한국응용과학기술학회지
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• 제34권2호
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• pp.217-224
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• 2017

본 연구는 강산 분위기에서 아연의 산화 환원 반응을 통한 폐수 중 질산성 질소 제거에 관한 연구이다. 폐수에 황산($H_2SO_4$)을 첨가하여 강산 분위기를 조성한 다음, 아연과 설파믹산을 넣어주게 되면 금속 아연이 산화되고, 이온화된 질산성 질소가 환원 처리되어 제거되는 연구이다. 산화 반응은 강산 분위기일수록 반응이 잘 일어나기 때문에 pH 2.0~4.0 범위 중 pH 2.0에서 제거효율이 높았다. 설파믹산을 첨가함으로써 질산 이온을 최종 질소가스로 환원시켜 제거하는 것이 설파믹산이 존재하지 않을 때보다 $H^+$ 이온 소모량이 적기 때문에 설파믹산을 투입하는 것이 유리하였다. 같은 아연 양에 따라 설파믹산을 넣지 않은 것은 질산성 질소가 46.0% 제거되는 반면, 설파믹산을 넣게 되면 질산성 질소가 93.0% 제거된다. 본 실험에서 아연은 입자가 분말 형태로 제조되어 반응성이 다른 일반 아연 금속보다 크기 때문에 반응 후 1분 만에 제거 효율이 약 80.0% 로 매우 높게 나타났다.