북동태평양(KODOS 해역)의 영양염 및 형광 유기물에 관한 환경특성 연구

손승규,박용철 한국환경과학회 1997 한국환경과학회지 Vol.6 No.6

To investigate characteristics of biogeochemical environment of the Korea Deep Ocean Study(KODOS) area in the northeast Pacific Ocean, we preferentially measured inorganic nutrients and fluorescent organic matters. Typically, the permanent thermocline was well developed at the depth of 200∼1000m in the study area. Nitrate, phosphate and silicate were low in the surface mixed layer and increased with depth. N/P and N/Si showed 15 and 0.2 respectively in the deeper layer. Two fluorophores, biomacromolecule(protein-like) and geomacromolecule (humic-like), were observed by three dimensional fluorescence excitation/emission spectra matrix. Biomacromolecule(maximum fluorescence at Ex_280nm/Em_330nm) ranged from 41.9 to 147.0 TU with its maximum in the surface mixed layer and minimum in deeper water. This is a same trend that has been reported for DOC in the equatorial Pacific. This suggests that biomacromolecule might be labile and converted to refractory humic substance after bacterial degradation in the deeper layer. On the contrary, geomacromolecule(maximum fluorescence at Ex_330nm/Em_430), ranged from 7.6 to 46.5 QSU, showed minimum in the surface mixed layer(euphotic zone) implying photodegradation and then increased with depth at all stations. In the characteristics of vertical profiles, the relationship between biomacromolecule and geomacromolecule showed negative correlation. Such trend can be attributed to biochemical regeneration or formation of fluorescent materials accompanying oxidation and remineralization of settling organic matter.

인도양 중앙해령 Hydrothermal Vent 해역의 화학적 환경특성

손승규,김경홍,손주원,김미진,문재운 대한조선학회 2011 대한조선학회 학술대회자료집 Vol.2011 No.6

Helicobacter pylori 감염의 치료와 Clarithromycin 내성간의 연관성

손승규,이종화,이정훈,이상희,Sohn Seung Ghyu,Lee Jong Hwa,Lee Jung Hun,Lee Sang Hee 한국미생물학회 2005 미생물학회지 Vol.41 No.3

본 연구를 수행하기 전에 H. pylori에 대한 어떠한 치료도 받지 않은 114명의 소화기 궤양 환자들을 내시경 검사를 하는 동안, 114개의 H. pylori 균주를 위 전정부로부터 분리하였다. H. pylori를 검출하기 위하여 rapid urease test, SSA와 cagA 유전자의 PCR증폭을 수행하였고, CagA 발현 검출을 위하여 Western blot을 수행하였다. H. pylori에 감염된 환자들은 omeprazole. clarithromycin (a macrolide), amoxicillin을 모두 사용하는데 3제 요법(triple therapy)으로 치료하였다. 치료가 중단되고 6주 후에 내시경 검사에서 세균 박멸률을 측정하였다. 내성률은 각각 clarithromycin이 $20.2\%$. amoxicillin이 $0.0\%$였다. Clarithromycin 내성은 H. pylori의 23S rRNA 유전자에 있는 A2142G돌연변이에 의한 것이 $87\%$이었다. A2142G돌연변이의 clarithromycin의 MIC값($32\~>256\;{\mu}g\ml$)은 A2143G돌연변이의 MIC값($4\~128\;{\mu}g/ml$)보다 더 높았다. Clarithromycin에 감수성을 가진 H. pylori는 박멸되었으나 clarithromycin내성을 가진 H. pylori는 박멸되지 않았다(P = 0.0001). 이러한 결과들은 CagA 발현에는 어떠한 영향도 받지 않았으며 H. pylori의 clarithromycin 내성은 치료 실패의 가장 중요한 이유임을 제시하였다. 우선적으로 실시되는 생검 배양에 대한 H. pylori의 항생제 감수성 시험은 감염된 환자들에 대한 3제 요법을 선택하기 이전에 필히 실시되어야 하며 국내에서 clarithromycin에 대한 1차 내성의 높은 빈도는 H. pylori의 감염증 치료에 심각한 문제점을 야기시켰다. H. pylori strains were isolated from antral biopsies taken during upper endoscopy in 114 dyspeptic patients with no previous therapy against H. pylori. Rapid urease test, PCR amplification of SSA and cagA gene for H. pylori detection, and Western blot for CagA expression detection were performed. H. pylori infected patients were treated with omeprazole, clarithromycin (a macrolide), and amoxicillin. At 6 weeks after the discontinuation of therapy, the bacterial eradication rate was determined by endoscopy. The resistance rate to clarithromycin and amoxicillin was $20.2\%$ and $0.0\%$, respectively. The clarithromycin resistance was mainly caused by the A2142G mutation in the 23S rRNA gene of H. pylori. MICs of clarithromycin for the A2142G mutant isolates were significantly higher than MICs for the A2143G mutant isolates. H. pylori eradication was obtained in all patients with clarithromycin-susceptible isolates but not in patients with clarithromycin-resistant isolates (P = 0.0001). These results did not appear to be biased by any differences in CagA expression. The resistance of H. pylori to clarithromycin included in the therapeutic regimens is the most important reason for treatment failure. H. pylori antimicrobial susceptibility testing of the gastric biopsy culture should be performed before choosing the first triple therapy in infected patients and the increase in prevalence of clarithromycin resistance in Korea was problematic.

북동태평양 KOMO 정점에서 수온약층에 따른 무기영양염 분포 특성 (1995-2002)

손승규,강정훈,박정기,유찬민,김웅서,손주원,김경홍,지상범 한국해양과학기술원 2004 Ocean and Polar Research Vol.26 No.2

Annual variations of inorganic nutrients such as nitrate(+nitrite), phosphate and silicate in association with thermocline were investigated in the upper 200 m of the water column at KODES Long-term Monitoring (KOMO) station in the northeast equatorial Pacific from 1995 to 2002. Global climatic disturbances such as El Nio and La Nia, should have affected KODES area during the study period. In 1995-97 and 2000-2002, a thermocline where temperatures rapidly decrease with depth, was formed at 50-70 m water depth. Nutrient depletion, specially for nitrate and phosphate, was extended down to approximately 50 m depth, which coincided with the surface mixed layer depth. In 1998 and 1999, however a very fluctuating thermocline was observed at 20-100 m water depth. In the photic zone (up to 100 m depth), depth integration of nitrate, phosphate and silicate ranged from 2.02 to 23.14 gN/m2, from 0.87 to 4.05 gP/m2 and from 35.67 to 176.21 gSi/m2, respectively. As a result of changes in the water column structures, nutrient concentrations also showed fluctuation parallel to the changes of thermocline in the study area.

북동태평양 해역의 용존 자유아미노산 분포 및 조성 연구

손승규,박용철,이경용,김기현,이효진,Son, Seung-Kyu,Park, Yong-Chul,Lee, Kyeong-Yong,Kim, Ki-Hyune,Lee, Hyo-Jin 한국해양학회 1999 바다 Vol.4 No.4

북동태평양($9^{\circ}54'{\sim}10^{\circ}27'N$, $131^{\circ}43'{\sim}131^{\circ}53'W$)에서의 용존 자유아미노산 농도는 15.9~1778.2 nM의 범위를 갖으며, 평균 407.2 nM을 보였다. 표층 혼합층에서의 용존 자유아미노산은 60.1~1411.9 nM의 범위로 평균. 535.2 nM을 보였으며, 계절 수온약층이 형성된 수심 50~150 m의 수층에서는 91.7~1778.2 nM의 범위와 평균 588.5 nM의 값으로 최대치를 포함하고 있었다. 또한 저층까지의 수층에서는 15.9~384.2 nM의 범위와 평균 175.1 nM을 나타내었다. 연구해역의 모든 정점에서 glycine, alanine, glutamic acid, serine 그리고 valine 등이 전체 농도의 약 60% 이상을 차지하며 우점하였고, isoleucine, tyrosine, methionine 그리고 phenylalanine 등은 낮은 비율을 보였다. 아미노산 작용기단별 몰%는 aliphatic neutral이 평균 59%로 가장 높았으며 aliphatic hydroxy 16%, acidic 12%의 순으로 나타났다. 총아미노산의 농도가 수층별로 유광층에서 높고 저층이 상대적으로 낮은 분포를 보이고 있으나, 각 아미노산의 조성 비율은 매우 유사하게 나타나고 있었으며 이러한 결과는 미생물작용 및 각 아미노산들의 수용성 등에 의하여 일정하게 유지되고 있는 것으로 사료된다. Concentrations of total dissolved free amino acids (DFAAs) in the northeast Pacific Ocean $9^{\circ}54'-10^{\circ}27'N$, $131^{\circ}43'-131^{\circ}53'W$) ranged from 15.9 to 1778.2 17M, and the average was 407.2 nM. Concentrations of DFAAs in surface mixed layers, ranged from 60.1 to 1411.9 nM, and the average was 535.2 nM. Seasonal thermoclines with maxima were formed between the depth of 50 to 150 m. DFAAs in this layer were varied in concentrations from 91.7 to 1778.2 nM, and the average was 588.5 nM. DFAAs below the seasonal thermoclines fluctuated from 15.9 to 384.2 nM, and the average was 175.1 nM. Consequently, in average relatively abundant DFAAs were observed in the subsurface layer than the deeper layer. DFAA vertical profiles and compositions of station A showed similar to station Band C. Glycine, alanine, glutamic acid, serine and valine were predominant accounting for more than 60% of total amino acids. Isoleucine, tyrosine, methionine and phenylalanine comprised only few percents of total DFAAs in the study area. In mole % of amino acid, according to characteristics of functional group of amino acid, aliphatic neutral accounted for 59% and aliphatic hydroxy 16%, acidic 12%, respectively. Although differences in DFAA concentrations with depth were observed, the amino acid composition and mole % of deeper layers in all stations were similar to those of subsurface layers. The results indicate that individual DtAAs remains invariably in water columns relative to the compositions and distributions of DFAAs in the study area, which may be the result of close coupling between microbial activity and their water solubility.

북동적도태평양 표층 수온변화에 따른 화학적 환경 특성

손승규(Seung-Kyu Son),현정호(Jung-Ho Hyun),박정기(Cheong-Kee Park),지상범(Sang-Bum Chi),김기현(Ki-Hyune Kim) 한국해양환경·에너지학회 2001 한국해양환경·에너지학회지 Vol.4 No.1

황해 중부의 영양염과 용존 아미노산 및 미생물 분포의 계절변화

손승규(Seung Kyu SON),정경호(Kyung Ho CHUNG),조준성(Jun Sung JO),박용철(Yong Chul PARK) 인하대학교 해양과학기술연구소 1989 黃海硏究 Vol.2 No.5

한국심해연구해역에서 수온약층 변화에 따른 무기영양염(질소, 인)의 연변화 특성

손승규(Seung-Kyu Son),김경홍(Kyeong-Hong Kim),손주원(Ju-Won Son),김기현(Ki-Hyune Kim) 한국해양환경·에너지학회 2002 한국해양환경공학회 학술대회논문집 Vol.2002 No.-

황철석의 표면 거칠기와 접촉각의 관계

정문영,손승규,허원 한국자원공학회 2014 한국자원공학회지 Vol.51 No.3

황철석 시편은 그의 표면 거칠기에 상관없이 측정시간이 30초 경과함에 따라 접촉각이 약 5°차이가 발생하였다. 따라서 sessile drop법으로 접촉각을 측정할 경우에는 접촉시간에 따른 오차를 배제하기 위해서 측정시간을 고정하는 것이 중요하다. 광물학적으로 균질한 황철석 시료를 취하여 평탄하게 제조한 시편인데도 불구하고 측정위치에 따라 접촉각에 많은 차이를 보이고 있었다. 이는 주로 광물 표면의 거칠기 때문에 나타나는 현상으로 황철석의 접촉각은 표면 거칠기가 증가함에 따라 약간 감소하였다. 이는 Wenzel이론에 따라 친수성 표면에서 나타나는 전형적인 현상이다. 따라서 황철석의 소수화도를 증가시키려면 그의 표면 거칠기를 낮추는 것이 필요하다. There is approximately 5˚ difference in contact angle on the pyrite surface before and after 30 second interval measurement independent of roughness. Thus it is important to fix the measurement time to exclude the errors made from the contact time when contact angles are measured by sessile drop method. Though the samples, which were taken from the mineralogically homogeneous pyrite samples are evenly made, there are lots of differences in the contact angles according to the measurement positions. That was mostly due to the surface roughness of minerals. The contact angles of pyrite samples decreased slightly as the surface roughness increased. It is a typical phenomenon that it appears in hydrophilic surfaces depending on the Wenzel theory. Therefore it is necessary to lower the surface roughness to increase hydrophobicity of pyrite.

북동태평양에서 형광 기법을 이용한 용존유기물의 기원 및 분포

손주원,손승규,주세종,김경홍,김웅서,박용철 한국해양과학기술원 2007 Ocean and Polar Research Vol.29 No.2

This study was conducted to understand the source and behavior of organic matter using the fluorescent technique (excitation-emission matrix) as a part of environmental monitoring program in the Korea manganese nodule mining site in the Northeastern Pacific Ocean. Water samples were collected at 0o, 6oN, and 10.5oN along 131.5oW in August 2005. The concentration of total organic carbon (TOC) ranged from 58.01 to 171.93 mM-C. The vertical distribution of TOC was characterized as higher in the surface layer and decreased with depth. At 6oN, depth-integrated (from surface to 200 m depth) TOC was 337.1 gC/m2, which was 1.4 times higher value than other stations. The exponential decay curve fit of vertical profile of TOC indicated that 59% of organic carbon produced by primary production in the surface layer could be decomposed by bacteria in the water column. Dissolved organic matter is generally classified into two distinctive groups based on their fluorescence characteristics using three-dimensional excitation/emission (Ex/Em) fluorescence mapping technique. One is known as biomacromolecule (BM; protein-like substance; showing max. at Ex 280/Em 330), mainly originated from biological metabolism. The other is geomacromolecule (GM; humic-like substance; showing max. at Ex 330/Em 430), mainly originated from microbial degradation processes. The concentration of BM and GM was from 0.42 to 7.29 TU (tryptophan unit) and from 0.06 to 1.81 QSU (quinine sulfate unit), respectively. The vertical distribution of BM was similar to that of TOC as high in the surface and decreased with depth. However, the vertical distribution of GM showed the reverse pattern of that of BM. From these results, it appeared that BM occupied a major part of TOC and was rapidly consumed by bacteria in the surface layer. GM was mainly transformed from BM by microbial processes and was a dominant component of TOC in the deep-sea layer.