흑연층간 효율적 화합물 도입 방식을 이용한 그래핀 제조

고동규,김현,한아름,한종훈 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.1

그래핀은 탄소 원자가 강한 공유결합을 통해 육각형으로 결합해 벌집 형태를 이루는 2차원 평면 구조를 가지면서 원자 한 층의 두께(0.35 nm)를 가지는 화합물이다. 단결정 실리콘의 100배에 이르는 높은 전하 이동도와 구리의 100배에 이르는 전류 밀도 특성을 가지며, 강도는 강철보다 200배 강하며, 최고의 열전도도를 보이는 다이아몬드보다 2배 이상 열전도도(구리 10배)가 높다. 내화학성이 뛰어나고, 우수한 유연성과 신축성을 가진다. 이와 같은 그래핀의 우수한 특성으로 인해 많은 응용분야에 사용될 것으로 예상되나 현재 제조되고 있는 그래핀은 기계적 처리에 의해 면적이 작은 그래핀이 제조되고 있으며 복합소재를 포함한 그래핀의 다양한 응용을 위해서는 저두께의 대면적 그래핀 합성기술이 필요하다. 본 연구에서는 흑연층 사이에 화합물을 효율적으로 삽입시켜 대면적 그래핀을 제조하였다.

금강수역내 항생제 및 중금속내성균의 분포 및 동시내성빈도

이기성,고동규,최원창,오태엽,박영식,최청일,최영길 ( Ki Sung Lee,Dong Kyu Ko,Won Chang Choi,Tae Youp Oh,Young Sik Park,Chung Il Choi,Yong Keel Choi ) 한국환경생물학회 1993 환경생물 : 환경생물학회지 Vol.11 No.2

As the basic study to solve the recent big problems upon the bacterial multi-drug resistance recognizing seriously from the viewpoint of microbial ecology, clinical medicine and public health, this study was carried out temporally and spatially upon Kum river area that has been recently accelerated the pollution for the purpose of analysis such as distribution of heterotrophic bacteria, distribution of resistant bacteria upon prevalently utilizing antibiotics(Ampicillin, Amp ; Chloramphenicol, Cm ; Tetracycline, Tc ; Kanamycin, Km ; Streptomycin, Sm) and heavy metal(mercury, Hg ; cadmium, Cd), frequency of multi-drug resistances, frequency of resistant factor transfer, compatibility and/or incompatibility. In May, 1992, community sizes of total heterotrophic bacteria reached to 5×10 exp (7)CFU/㎖ in site 1(1S, Kapchun stream`s water), 5×10 exp (8)CFU/㎖ in site 2(2S, Kapchun soil) where industrial and domestic sewages were chiefly flowed, and reached to 1×10 exp (8)CFU/㎖ in site 3(3S, Sanne stream`s water), 1×10 exp (7)CFU/㎖ in site 4(4S, Sanne soil) where agricultural domestic sewages were. Total heterotrophic bacteria in Kapchun area(1S, 2S) were distributed 50 times higher than those in Sanne area(3S, 4S) respectively. Compared with water, soil contained 10 times higher in heterotrophic bacteria. Of heterotrophic bacteria, compositional ratios of resistant bacteria upon antibiotics and heavy metals were shown to the level of 0.07% in May, 1992 and to the level of 0.2% in October, 1992. So, frequency of resistant bacteria increased in October about 3 times higher than in May. The frequent order of resistant factor was Tc, Km, Cd, Amp, Hg, Cm, in May, 1992 and was Cd, Amp, Sm, Hg, Km, Tc, Cm, in October, 1992, respectively. Especially, Cd resistant bacteria were distributed upon all experimental sites more frequently in October, 1992 than in May, 1992. Passing through the rainy period in summer, the distributional change of resistant bacteria indicate strong evidence for the influx of large amount of sewage containing lots of resistant bacteria and of pollutants to the Kum river area. Considering the genetic linkage between antibiotics resistance and heavy metal resistance and distributional change of multi-drug resistant bacteria, resistant factor such as Tc, Amp, Cd were shown the highest frequency of simultaneous coexistence, so they are closely linked with other resistant factors the most from the viewpoint of molecular genetics. Most of resistant bacteria comprise generally simultaneous multi-drug resistance upon 5 to 3 drugs. As especial results, considering the relationship of simultaneous coexistence in antibiotics and heavy metal resistance, Cd resistance bacteria comprise other resistance factors such as Tc(70%) and Amp(68%) simultaneously and frequently and Hg resistant bacteria, such as Tc(80%) and with Cd(70%). In the transferability and incompatibility upon resistant factors, only 1% of resistant factors was the conjugative, transferable type plasmid, and 99% of them showed the incompatibility in the other strains.

대청호 및 금강수역의 유기물 분해능과 오염의 신호지표

이기성,고동규,박영식,최청일,최영길 ( Ki Sung Lee,Dong Kyu Ko,Young Sik Park,Chung Il Choi,Yong Keel Choi ) 한국환경생물학회 1995 환경생물 : 환경생물학회지 Vol.13 No.1

In order to test the microbiological degradability of organic compounds and self-clarification, cycle of phosphorus compound in Daechung Reservoir Lake and Kum River area, physico-chemical factors and various bacterial population were analyzed. Also exo-enzymes activities, the amount of chlorophyll, polyphosphate, and DNA amount of cells were measured during from April to September in 1993. As a result of physico-chemical factor analysis, self-clarification of Deachung Reservoir Lake on upstream of Kum River was recognized periodically. The community sizes of total heterotrophic bacteria were evenly distributed seasonally. However the community sizes of total heterotrophic bacteria in the middlestream and downstream were distributed higher than those in the upstream of Kum River. Also population densities of indicator microbes for the determination of pollution such as E. coli and antibiotics or heavy metal resistant bacteria were higher in Gapchun stream and the middlestream of Kum River than those in other areas. And the populations of the indicator microbes were tended to increase more during the summer than those in the other season. The various exo-enzymes were mainly contributed to the water environment, so the self-clarification of each sites may be proceeded gradually by the degradation of organic compounds. The amounts of poly-P were relatively high temporally before the blooming of phytoplankton. It was also high in the polluted area that the relative ratios of poly-P to DNA or to chlorophyll can be applied usefully for the biological index checking the unbalanced and eutrophicated state of nutrition in environment.

금강수역내 항생제 및 중금속 내성균의 분포 및 동시내성빈도

최원창,고동규,이기성 한국미생물생명공학회 1993 한국미생물생명공학회 학술발표초록집 Vol.1993 No.1

대청호의수심에 따른 유기물 분해능과 오염의 신호지표

이기성,고동규,박영식,최청일,최영길 ( Ki Sung Lee,Dong Kyu Ko,Young Sik Park,Chung Il Choi,Yong Keel Choi ) 한국하천호수학회 1995 생태와 환경 Vol.28 No.2

In order to test the vertical variations upon microbiological degradability of organic compounds and self-clarification, cycle of phosphorus compound in Daechung Reservoir Lake, physico-chemical factors, various bacteria were analyzed, exo-enzyme activities, DNA and polyphosphate contents by the DAPI fluorescent staining methods, and the amount of chlorophyll were measured vertically during the period from April to September in 1993. As a result of physico-chemical factor analysis, self-purification of Oeachung Reservoir Lake was recognized periodically. Total heterotrophic bacteria in the hypoliminion were populated higher than those in the surface layer respectively. Therefore, it was expected that the organic compounds were accumulated in the hypoliminion. The dominance upon C-P compound degrading bacteria, phosphorus redox bacteria in the depth of water showed seasonally evenly distributed. The micromolecules converted from macromolecules by the exo-enzymes produced from microbes is available for the nutrient source for the microbes. These various exo-enzymes were mainly contributed to the water environment, so the self-clarification may be proceeded gradually by the degradation of organic compounds. The amounts of poly-P were relatively high before the blooming of phytoplankton temporally. Therefore, the relative ratios of poly-P to DNA or to chlorophyll can be applied usefully for the biological index checking the the unbalanced and eutrophicated state of nutrition in environment.

[P5-40] 옥수수 수염에서 분리된 Bacillus polymyxa JYP-001 균주의 항진균 물질의 정제 및 특성

박지영,고동규,이종화 한국식품영양과학회 2007 한국식품영양과학회 학술대회발표집 Vol.2007 No.10

금강수역내에서 분리된 몇 종의 Ampicillin 내성균의 β-Lactamase 발현양상

이기성,고동규,최원창,문영길,박영식,최청일,최영길 ( Ki Sung Lee,Dong Kyu Ko,Won Chang Choi,Yong Keel Mun,Young Sik Park,Chung Il Choi,Yong Keel Choi ) 한국환경생물학회 1994 환경생물 : 환경생물학회지 Vol.12 No.1

In order to characterize the bacterial β-lactamase types occurred in Kum river area, this research was designed to analyze with identification upon ampicillin (Amp) resistant bacteria, and was investigated into relationships between β-lactamase expression (inducibility) and growth phase under ampicillin shift and with restriction patterns of R-plasmids. As the identification result upon 4 strains of Amp resistant bacteria, KL 601 is identified as Pasteurella maltocida, KL 602 as Enterobacter agglomerans, KL 609 as Pseudomonas maltophilia and KL 611 as Acinetobactor calcoaceticus, respectively. In order to investigate Amp effect upon growth, when the Amp resistant bacteria were cultivated in nutrient liquid LB medium, in LB medium added with Amp, or in LB medium in the manner of Amp shift, the changes in growth rate and lag phase could not be observed. However, upon the prototrophic strains, KL 602 and KL 609, examining Amp effect upon these two strains in minimal GM63 liquid media, even though there was no change of maximum growth yield, the latent lag phase become very lengthened. In nutrient medium, β-lactamase activities of these 4 strains were metabolically regulated in accordance with growth phase, on the other hand, in minimal medium were differently regulated in accordance with growth phase and with strains. It could be postulated that KL 609 strain has the M.W.24,000, β-lactamase type which E. coli comprise, however, that KL 601, KL 602 and KL 611 have the M.W.35,000, β-lactamase type which E. cloacae or C. freundii comprise. Through the whole growth phase, since Amp did not affect to phosholipid metabolism, there is no change in phospholipid compisition upon Amp effect. Main phospholipid are the phosphatidyl glycerol and cardiolipin in all 4 Amp resistant strains. So, it was very significant that there were no changes in phospholipid composition and in growth rate upon nutrient medium under Amp stress. In order to recognize whether Amp resistant strains comprise the plasmid or not, preparation of plasmids and restriction digestion with Bam H1 were carried out, KL 601 strain has about 30 Kb of plasmid, KL 609 and KL 611 strain have about 25 Kb of plasmid and KL 602 does not have the plasmid, however. Hence, it will be predicted strongly that β-lactamase gene in KL 602 might be encoded chromosomally. Moreover, considering the results upon the changes of β-lactamase acticity, upon β-lactamase inducibility and upon changes of periplasmic protein profile under Amp stress, its prediction is very recognizable.

동해 연안역의 영양염과 유기물질의 분표

이기성(Ki Sung Lee),고동규(Dong Kyu Ko),허승(Seung Huh),이영근(Young Keun Lee),최청일(Chung Il Choi),최영길(Yong Keel Choi) 한국환경생물학회 1999 환경생물 : 환경생물학회지 Vol.17 No.1

To investigate the distribution of nutritive salts and organic compounds in six stations at the coastal area of East Sea, environmental factors, nutritive salts, organic matters and chlorophyll were analysed four times from July 1994 to April 1995. The value of BOD in Ulsan Chuyongam was the highest among 6 stations. The concentration of nutritive salts was generally high through the investigation period near Pohang and Ulsan Chuyongam. From the value of dissolved nutrient salts, the Chuyongam area seemed to be under hyper-eutrophi-cation and the Changsengop area under eutrophication. Suspended particulate matter(SPM) of 3∼10㎛ in size was distributed up to 70% of total volume. The amounts of SPM and particulate organic matter(POM) were considerably high in Pohang and Ulsan, which seemed to be resulted from the input of pollutants of cities and factories nearby.

동해 연안역의 박테리아 생산력과 유기물질의 분해능

이기성(Ki Sung Lee),고동규(Dong Kyu Ko),김근호(Guen Ho Kim),이영근(Young Keun Lee),최청일(Chung Il Choi),최영길(Yong Keel Choi) 한국환경생물학회 1999 환경생물 : 환경생물학회지 Vol.17 No.1

Bacterial population, signal compounds of pollution, bacterial productivity, heterotrophic activity and the activities of extracellular enzymes were analyzed four times from July 1994 to April 1995 at Daejin, Galnam, Pohang, and Ulsan in the coastal area of East Sea in order to investigate the state of eutrophication. The population of heavy metal resistant bacteria in Pohang was the highest among all stations. The bacterial populations which could utilize C-P compounds(phosphonate) showed the highest at Pohang that was expected for the industrial and agricultural effluents to inpour. It could be useful as an index of expectation about the influx of industrial sewages and agricultural effluents. The activities of extracellular enzymes for the degradation of organic matter were the highest in the Ulsan Chuyongam, but low in Daejin. These results showed positive relationship with the population of heterotrophic bacteria and bacterial productivity. The ratio of poly-P and DNA in Pohang was the highest, and that in Ulsan, Galnam, and Daejin consecutively, corresponding with the distribution of heterotrophic bacteria. In case of the heterotrophic activities, each of the stations gives difference of seasonal variation in heterotrophic activities. Bacterial productivity seemed to be dependent on seasons; the highest in summer and the lowest in fall and winter. These seasonal variations of bacterial productivity seems to be similar with those of heterotrophic bacteria. It is suggested that the state of eutrophication could be evaluated by the criteria of the population sizes and the productivities of microorganisms, the amount of poly-P, heterotrophic activity, the activities of extracellular enzymes, etc.

이온화방사선에 의한 느타리버섯(Rleurotus ostreatus)의 ITS2 염기서열 변화

이영근,장화형,한갑진,고동규,이기성 한국환경생물학회 1998 환경생물 : 환경생물학회지 Vol.16 No.4

rDNA의 ITS2(internal transcribed spacer 2)부위에 대한 이온화방사선(gamma-ray)의 영향을 알아보기 위해서 감마선을 조사한 느타리버섯(Pleurotus ostreatus)의 5종의 변이중에서 ITS2의 염기서열을 결정하였다. ITS2의 염기서열은 1 kGy 조사군(PO-5, PO-6, PO-15와 PO-16)에서 변화되지 않았으나, 2kGy 조사군(PO-14)에서는 1개의 염기가 치환되었다. RAPD(ramdomly amplified polymorphic DNA) 양상에 의한 유전유사도의 변화가 다양하였고 섬유소성 고체검정 배지에서도 다양한 생장특성을 나타내었다. 본 연구결과는 ITS염기서열이 이온화 방사선에 의해 선량의존적으로 변화될 수 있음을 시사해 주었다.