• 한국축산식품학회지
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• 제31권5호
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• pp.710-718
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• 2011

The effects of organic acids mix (0.4%) and modified atmosphere packaging (MAP) on the storage quality of sliced bacon were investigated. Pork bellies were treated with or without organic acids at the curing stage. The organic acids mix comprised 35% sodium acetate, 25% salt, 15% calcium lactate, 11% trisodium citrate, 7% ascorbate, and 7% citric acid. The cured pork bellies were smoked and packaged with 50% $CO_2$ + 50% $N_2$ (50% $CO_2$-MAP) and 100% $N_2$ (100% $N_2$-MAP), and stored at $5^{\circ}C$ for 14 d. The 50% $CO_2$-MAP showed a higher pH value (p<0.05) up to 10 d, a lower protein deterioration (p<0.05) as measured by volatile basic nitrogen (VBN) from 6 to 14 d, and a higher color value of lightness (CIE $L^*$) compared to 100% $N_2$-MAP. The development of lipid oxidation measured by thiobarbituric acid reactive substance (TBARS) values seemed to be effectively controlled throughout the storage period in both 50% $CO_2$-MAP and 100% $N_2$-MAP regardless of the application of organic acids. The 50% $CO_2$-MAP inhibited the growth of aerobic and anaerobic bacteria (p<0.05) both in non-added and bacon added with organic acids mix. The 50% $CO_2$-MAP alone seemed to be effective in delaying the growth of bacteria since the use of organic acids mix gave no additional effects. The addition of organic acids mix lowered the pH value (p<0.05), effectively retarded the protein deterioration (p<0.05), and showed a higher color value of lightness (CIE $L^*$) value (p<0.05) and lower color value of redness (CIE $a^*$) value (p<0.05). In conclusion, 50% $CO^2$-MAP showed better quality and self-life of sliced bacon during storage. However, the beneficial effect of organic acids mix was not noticed in the concentration used in this experiment.

• 한국식품저장유통학회지
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• 제5권1호
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• pp.57-63
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• 1998

To furnish basic data about the utilization of Korean loquat as flood, this experiment was conducted. Nutritional components in leaves, fruit excluded seed, flesh and seed of Korean loquat were analyzed as follows : moisture 48.7%, 87.8%, 88.3% and 59.5% ; total sugar 1.57%, 7.21%, 7.36% and 2.41% ; crude protein 5.23%, 1.61%, 1.44% and 4.31% in each portion, respectively. The highest mineral contents of loquat leaves, fruit excluded seed, flesh and seed were Ca 2,458ppm, K 661ppm, 654ppm and 1,528ppm, and water soluble vitamins such as ascorbic acid, thiamin and pyridoxine were confirmed in different pares of Korean loquat, the contents of those were high thiamin 5.86mg% in leaves and ascorbic acid 1.l0mg%, 1.26mg% and 4.90mg% in fruit excluded seed flesh and seed, respectively. The contents of free sugars were high sucrose 0.87%, glucose 0.62%, 0.6475 and rhamnose 0.20%, and major organic acid were detected oxalic acid 1,693.70mg%, malic acid 201.70mg%, 207.60mg% and citric acid 55.70mg% in each portion, respectively. Free amino acid were identified 21, 14, 14 and 16 kinds of leaves, fruit excluded seed, flesh and seed, respectively and their contents in each portion were highest glutamic acid 280.22mg%, proline 35.l0mg%, glutamic acid 56.96mg% and sarcosine 230.24mg%, respectively. Volatile components were identified 25 and 11 kinds of leaves and flesh and their contents were highest d-nerolidol 28.70ppm, hexadecanoic acid 16.67ppm, respectively.

• 한국미생물·생명공학회지
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• 제19권2호
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• pp.135-139
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• 1991

Tridecanedioic acid (DC-13), starting material of the valuable musk ethylene brassylate, was obtained from n-tridecane by the Candida tropicalis mutant. The mutants were first obtained from primary screening step using the selective medium and then solid phase extraction sampling method was used for the selective isolation of organic acids from the cultured media of mutants. The resulting acids were directly converted to volatile tert-butyldimethyl silyl delivatives, which were then analyzed by gas chromatography. The efficient GC profiling method was used for the rapid identification of the mutant producing DC-13 in large quantity, and for the optimization of the culture conditions of mutant. The optimal culture conditions were found as follows: pH 8.0, 30$^{\circ}C$, 250rpm, 48hour of culture and $(NH_4)_2HPO_4$ as nitrogen source.

• 센서학회지
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• 제26권6호
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• pp.420-426
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• 2017

A colorimetric sensor was investigated to achieve a low-cost warning device for harmful gaseous formaldehyde (HCHO). The sensor is based on selective reactions between hydroxylamine sulfate and HCHO, leading to the production of sulfuric acid. The produced acid results in color-changing response through the acid-base reaction with dye molecules impregnated on a solid membrane substrate. For attaining this purpose, sensors were fabricated by drop-casting a dye solution prepared using different pH indicators on various commercially available polymer sheets, and their colorimetric responses were evaluated in terms of sensitivity and reliability. The colorimetric sensor using bromophenol blue (BPB) and nylon sheet was found to exhibit the best performance in HCHO detection. An initial bluish green of a sensor was changed to yellow when exposed to gaseous formaldehyde. The color change was recorded using an office scanner and further analyzed in term of RGB distance for quantifying sensor's response at different HCHO(g) concentrations. It exhibited a recognizable colorimetric response even at 50 ppb, being lower than WHO's standard of 80 ppb. In addition, the sensor was found to have quite good selectivity in HCHO detection under the presence of common volatile organic compounds such as ethanol, toluene, and hexane.

• 한국미생물·생명공학회지
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• 제47권1호
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• pp.1-10
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• 2019

Saline soils comprise more than half a billion hectares worldwide. Thus, they warrant attention for their efficient, economical, and environmentally acceptable management. Halophytes are being progressively utilized for human benefits. The halophyte microbiome contributes significantly to plant performance and can provide information regarding complex ecological processes involved in the osmoregulation of halophytes. Microbial communities associated with the rhizosphere, phyllosphere, and endosphere of halophytes play an important role in plant health and productivity. Members of the plant microbiome belonging to domains Archaea, Bacteria, and kingdom Fungi are involved in the osmoregulation of halophytes. Halophilic microorganisms principally use compatible solutes, such as glycine, betaine, proline, trehalose, ectoine, and glutamic acid, to survive under salinity stress conditions. Plant growth-promoting rhizobacteria (PGPR) enhance plant growth and help to elucidate tolerance to salinity. Detailed studies of the metabolic pathways of plants have shown that plant growth-promoting rhizobacteria contribute to plant tolerance by affecting the signaling network of plants. Phytohormones (indole-3-acetic acid and cytokinin), 1-aminocyclopropane-1-carboxylic acid deaminase biosynthesis, exopolysaccharides, halocins, and volatile organic compounds function as signaling molecules for plants to elicit salinity stress. This review focuses on the functions of plant microbiome and on understanding how the microorganisms affect halophyte health and growth.

• 한국초지조사료학회지
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• 제34권2호
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• pp.120-124
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• 2014

초지 또는 농경지에 살포되는 퇴비와 액비에 의해 발생될 수 있는 악취민원에 대처하기 위하여, 돼지의 분과 뇨에 존재하는 악취물질 농도를 비교 분석하였다. 1. 비육돈의 분과 뇨에 함유된 휘발성유기물의 농도 비교 페놀, p-크레졸 및 페놀류 농도는 분 보다 뇨에서 높았으며 (p<0.05), 분 보다 뇨에 축적된 비율이 페놀은 138배, p-크레졸은 545배 높았다. 인돌 농도는 분 보다 뇨에서 높았으며, 스카톨은 뇨 보다 분에서 높았다 (p<0.05). 휘발성유기물은 대부분 뇨로 배설되었으며, 이 중 농도 및 악취강도가 가장 높은 물질인 p-크레졸이 뇨에 많이 함유되어 있다. 돼지 분뇨를 고액분리 하였을 때 퇴비로 이용되는 고체보다 액비로 이용되는 액상물질에서 악취가 훨씬 강할 것으로 예측된다. 2. 비육돈의 분과 뇨에 함유된 휘발성지방산의 농도 비교 아세트산과 단쇄지방산 농도는 분 보다 뇨에서 높았으며 (p<0.05), 부티르산과 프로피온산은 차이가 없었다 (p>0.05). 이성체지방산 중 I-부티르산의 농도는 뇨 보다 분에서 높았지만 (p<0.05), I-발레르산과 이성체지방산은 차이가 없었다 (p>0.05). 휘발성지방산 중에서 아세트산과 프로피온산은 분에서 각각 65와 20%, 뇨에서는 각각 93과 4%로 휘발성지방산의 대부분을 차지하였지만 아세트산과 프로피온산을 포함하는 단쇄지방산은 악취강도가 낮다. 반면에 악취강도가 상대적으로 높은 이성체지방산은 분과 뇨 간에 차이가 없기 때문에 휘발성지방산이 악취강도에 미치는 영향은 크지 않을 것으로 판단된다. 이상의 연구결과를 종합하면, 돼지 분뇨의 악취물질 중 악취강도가 높은 p-크레졸은 뇨에 많이 함유되어 있기 때문에 퇴비와 액비 생산과정 중 액상처리 시 악취강도가 매우 높을 것으로 추정된다. 다만, 악취강도는 휘발성지방산의 농도 변화에 따라 차이가 있을 것으로 생각된다.

• 한국수산과학회지
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• 제46권4호
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• pp.424-436
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• 2013

Organic enrichment was investigated in surface sediments from the Yeoja and Gangjin Bays of Korea, which contain dense shellfish farms, in order to evaluate the contamination status and temporal changes in shellfish farming along these coasts. The degree of organic enrichment was determined using geochemical indicators (chemical oxygen demand, ignition loss, acid volatile sulfide, total organic carbon in sediments, and total nitrogen in sediments, ammonium and nitrate in pore water, and bioluminescence inhabitation for sediments). Temporal changes in organic enrichment conditions were detected by comparing our 2012 data to those previously reported from a survey conducted in 1999/2000. Organic enrichment was significantly higher in September than in May and July, in Gangjin Bay than in Yeoja Bay, and significantly higher in shellfish farms than in reference sites not used to culture shellfish. Ammonium concentrations in pore water were two orders of magnitude greater than nitrate concentrations, suggesting that these bays represent nitrogen-reducing environments.

• 한국수산과학회지
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• 제46권6호
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• pp.930-940
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• 2013

We evaluated contamination with organic matter and trace metals by analyzing grain size, ignition loss (IL), chemical oxygen demand (COD), acid volatile sulfide (AVS), and trace metals (Al, Fe, Cu, Pb, Zn, Cd, Ni, Cr, Mn, Hg, and As) in surface sediments at 28 stations around the Geum River estuary in July 2008. The surface sediments in the estuary were mainly composed of coarse sediment (sand and muddy sand), with mean grain size (Mz) ranging between $2-4{\O}$. The high concentrations of IL, COD, and trace metals were mainly found at stations in front of the Gusan outer port and industrial complex, and near the Seocheon coast with relatively fine sediments. In addition, the concentrations of IL and all trace metals, except Pb and As, showed good positive correlations with Mz, indicating that the concentrations of organic matter and trace metals were mainly dependent on sediment grain size. The concentrations of COD, AVS, and trace metals in most sediments did not exceed the sediment quality guideline (SQGs). Although the sediments in the study region are not polluted with organic matter and trace metals, there are many point sources of pollutants, such as Gusan port and industrial complex, Janghang refinery, and a thermoelectric power plant around the Geum River estuary. Thus, the management of coastal environments through periodic monitoring of organic matter and trace metals is required in the future.

• 청정기술
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• 제28권2호
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• pp.131-137
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• 2022

현재 반도체 공정에서 다양한 by-product 및 미사용 가스가 배출되고 있다. 오염물질을 함유한 배기는 일반적으로 유기, 산, 알칼리, 열, 캐비넷 배기 등으로 분류하며, 각각의 배기 특성에 맞는 대기 방지설비에서 처리 후 배출된다. 유기 배기 물질로서 휘발성 유기 화합물(volatile organic compound, VOC)은 산소 함유 탄화수소, 유황 함유 계 탄화수소 및 휘발성 탄화수소를 총칭하는 물질이고, 알칼리 배기의 주요성분은 암모니아(NH₃), 수산화테트라메틸암모늄(Tetramethylammonium hydroxide, TMAH)등이 있다. 본 연구의 목적은 유기와 알칼리 배기가스를 동시에 처리하기 위해 직접 연소 및 로 내 온도를 일정하게 유지하여 연소 특성 파악하고 NO_X 저감률을 분석하고자 진행하였다. VOC는 Acetone, IPA(isopropyl alcohol), PGMEA(propylene glycol methyl ether acetate)을 사용하였으며, 알칼리 배기 대표 물질로는 암모니아를 사용하였다. 실험 변수로는 온도와 당량 비(equivalence ratio, ER)로 배기가스 특성을 살펴보았다. 물질별 단독 및 혼합 연소테스트를 진행하였다. VOC 단독 테스트 결과 당량 비 1.4 조건에서 완전 연소가 일어남을 확인하였다. 암모니아는 당량 비 감소에 따라 산소 및 질소산화물의 농도가 감소하였다. 혼합 연소 운전 결과 배기가스 조성 내 질소산화물의 대부분은 일산화질소였으며 이산화질소는 10 ppm 부근으로 검출되었다. 전체적으로 질소산화물의 농도는 반응온도가 증가하면서 산화반응이 활성화되어 감소하는 경향을 나타나지만 이산화탄소의 농도는 증가하는 경향을 확인하였다. 전기열원을 적용한 무 화염 연소 기술을 적용하였을 때 VOC 및 암모니아 연소가 원활하게 일어남으로써 현재 별도로 운전되는 유기 및 알칼리 배기 시스템보다 경제성 및 공간적인 측면에서 장점이 있다고 판단된다.

• The Plant Pathology Journal
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• 제38권2호
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• pp.115-130
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• 2022

Though information exists regarding the pathogenesis of the shot-hole disease (SH) in flowering cherry (FC), there has been a lack of research focusing on SH management. Therefore, here, we investigated the inhibitory activities of antagonistic bacteria against SH pathogens both in vitro and in vivo as well as their biochemical characteristics and bioactive compounds. Two biosurfactant-producing bacterial antagonists, identified as Bacillus velezensis strains JCK-1618 and JCK-1696, exhibited the best effects against the growth of both bacterial and fungal SH pathogens in vitro through their cell-free culture filtrates (CFCFs). These two strains also strongly inhibited the growth of the pathogens via the action of their antimicrobial diffusible compounds and antimicrobial volatile organic compounds (VOCs). Crude enzymes, solvent extracts, and biosurfactants of the two strains exhibited antimicrobial activities. Liquid chromatography/electrospray ionization time-of-flight mass spectrometric analysis of the partially purified active fractions revealed that the two antagonists produced three cyclic lipopeptides, including iturin A, fengycin A, and surfactin, and a polyketide, oxydifficidin. In a detached leaf assay, pre-treatment and co-treatment of FC leaves with the CFCFs led to a large reduction in the severity of the leaf spots caused by Epicoccum tobaicum and Bukholderia contaminans, respectively. In addition, the two antagonists produced indole-3-acetic acid, siderophore, and a series of hydrolytic enzymes, along with the formation of a substantial biofilm. To our knowledge, this is the first report of the antimicrobial activities of the diffusible compounds and VOCs of B. velezensis against the SH pathogens and their efficiency in the biocontrol of SH.