• 한국미생물·생명공학회지
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• 제26권4호
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• pp.303-308
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• 1998

충북 청주시의 공단폐수 유입지로부티 탈질화에 의한 페놀분해 세균이 분리되었다. 분리된 균의 형태적, 생화학적 및 생리학적 특성을 분석한 결과 Pseudomonas sp.로 판명되었고 HL100으로 명명하였다. 분리된 균은 nitrate가 최종전자 수용체로서 공급되는 경우 페놀을 단일 탄소 및 에너지원으로 이용하였다. 배지에 첨가된 nitrate가 nitrite로 환원되면서 3mM의 페놀을 약 110시간만에 완전히 분해하였으며 관찰된 최대 doubling time은 20시간이었다. 적절한 조건에서 nitrate로부터 $N_2$를 생성하는 능력을 보여 분리된 균의 경우 탈질작용의 전과정을 수행할 수 있는 것으로 확인되었다. 최적 생장온도와 pH는 각각 37$^{\circ}C$와 7.0으로 판명되었으며 탈질화에 의한 생장시 toluene을 탄소원으로 이용하였지만 Xylene과 benzene은 이용하지 못하였다.

• 멤브레인
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• 제19권1호
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• pp.25-33
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• 2009

PES/DMF/TSA/PVP 고분자용액을 물에 침지시 시키는 상전이 공정을 통하여 비대칭성이 향상된 PES 멤브레인을 제조하였다. PES (polyethersulfone) 용액에 응고제 (p-toluenesulfonic acid, TSA)와 습윤제 고분자 (polyvinylpyrrolidone, PVP)의 첨가와 습윤 상태에 노출 시간으로 일어나는 멤브레인 표면의 pre-coagulation 현상은 멤브레인의 구조적 특성과 투과량 특성에 있어 중요한 역할을 한다. PES 용액은 폴리에스터 필름에 코팅된 후 약 $72{\sim}144$초 동안 80%의 습도하에서 공기에 노출된 후 응고조에 침지되었다. Capillary flow porometer, FE-SEM과 수투과 평가장치를 통하여 멤브레인의 특성을 살펴보았다. TSA 20 wt%와 PVP 10 wt%가 첨가된 11 wt%의 PES 용액에서 멤브레인 구조의 비대칭성이 크게 향상되었으며 최소 기공충의 두께도 얇아짐을 볼 수 있었다. 그 결과로 수투과량에 큰 증가를 가져옴을 볼 수 있었다.

• 미생물학회지
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• 제47권3호
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• pp.194-199
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• 2011

알칼리성 protease를 생산하는 호알칼리성 균주를 분리하여 Bacillus pseudofirmus HS-54로 동정하였고, HS-54가 생산하는 알칼리성 protease를 ammonium sulfate 침전, DEAE cellulose chromatography, sephadex G-100 gel filtration을 통과시켜 정제하였는데, 정제된 protease의 분자량은 27 kDa이었다. 정제된 효소의 반응최적 pH는 10.0이었고 pH 7.0-11.0에서 비교적 안정하였다. 또한 정제된 효소의 반응최적 온도는 $50^{\circ}C$이었고 $10-55^{\circ}C$에서 안정하였다. 금속이온에 대한 영향은 $Ca^{2+}$와 $Mg^{2+}$ 등에 의해 효소활성이 촉진되었으나, $Hg^{2+}$, $Zn^{2+}$, $Cu^{2+}$, $Al^{3+}$ 등에 의해서 효소활성이 저해되었다. 본 효소는 PMSF에 의해 강하게 저해를 받는 것으로 보아 serine protease에 속하는 것으로 판단된다.

• 미생물학회지
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• 제40권2호
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• pp.139-146
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• 2004

일반 토양과 부엽토, 퇴비로부터 alkaline cellulase 생성이 우수한 균주를 분리한 후 형태적, 배양학적 및 생화학적 동정을 실시한 결과 호알칼리성 Bacillus sp. HSH-810 균주인 것으로 판명되었다. 분리균 Bacillus sp. HSH-810의 생육과 효소 활성은 $30^{\circ}C$와 pH 10.0에서 가장 높은 것으로 나타났다. 본 균주는 배지 중에 탄소원과 질소원, 무기염으로 1.0%의 CMC와 0.5%의 peptone, 0.02%의 $CaC1_2$, $CoC1_2$를 사용하였을 경우 최대의 alkaline cellulase생산성을 나타내었다. 효소의 최적 활성 pH와 온도는 각각 10.5와 $50^{\circ}C$였다. 이 효소는 pH 6.0-13.0과 $50^{\circ}C$의 온도에서 매우 안정하였다. 효소액에 계면활성제를 첨가하여 효소 활성을 측정한 결과, 효소액은 sodium-$\alpha$-olefin sulfonate (AOS)와 sodium dodecyl sulfonate (SDS), Tween 20, Tween 80에 대하여 안정성 이 높은 특징을 보였으나 0.1%의 linear alkyl-benzene sulfonate (LAS)를 첨가한 경우에는 효소 활성이 심하게 저해되었다.

• 한국환경과학회지
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• 제8권4호
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• pp.451-456
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• 1999

Microorganisms utilizing petroleum as substrate were screened from the seawater in Pusan coastal area. Among them, fifty strains utilized bunker-A oil as a sole carbon and energy source. Five of these fifty strains were selected to experiment this study. According to the taxonomic characteristics of its morphological, cultural and biochemical properties, the selected stains were named Pseudomonas sp. EL-12, Flavobacterium sp. EL-15, Acinetobacter sp. EL-18, Enterobacter sp. EL-27 and Micrococcus sp. EL-43, respectively. The optimal medium compositions and cultural conditions for assimilation of bunker-A oil by the selected strains were 1.5-2% bunker-A oil, 0.1% $NH_4NO_3$, 1-1.5% $MgSO_4$.$7H_2O$, 0.05-0.15% KCl, 0.1-0.15% $CaCl_2$.$2H_2O$, 2.5-3.5% NaCl, initial pH 8-9, temperature 3$0^{\circ}C$ and aeration, respectively. The utilization and degradation characteristics on the various hydrocarbons by the selected stains were showed that bunker oil, n-alkane and branched alkane compounds were highly activity than cyclic alkane and aromatic hydrocarbon compounds.

• BMB Reports
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• 제38권1호
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• pp.17-23
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• 2005

During the screening of xylanolytic enzymes from locally isolated fungi, one strain BCC14405, exhibited high enzyme activity with thermostability. This fugal strain was identified as Aspergillus cf. niger based on its morphological characteristics and internal transcribed spacer (ITS) sequences. An enzyme with xylanolytic activity from BCC14405 was later purified and characterized. It was found to have a molecular mass of ca. 21 kDa, an optimal pH of 5.0, and an optimal temperature of $55^{\circ}C$. When tested using xylan from birchwood, it showed $K_m$ and $V_{max}$ values of 8.9 mg/ml and 11,100 U/mg, respectively. The enzyme was inhibited by $CuSO_4$, EDTA, and by $FeSO_4$. The homology of the 20-residue N-terminal protein sequence showed that the enzyme was an endo-1,4-$\beta$-xylanase. The full-length gene encoding endo-1,4-$\beta$-xylanase from BCC14405 was obtained by PCR amplification of its cDNA. The gene contained an open reading frame of 678 bp, encoding a 225 amino acid protein, which was identical to the endo-1,4-$\^{a}$-xylanase B previously identified in A. niger.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1425_1426
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• 2009

In this study, commercially available polyethylene terephthalate(PET), which is widely used as a substrate of flexible electronic devices, was modified by dielectric barrier discharge(DBD) method in an air condition at atmospheric pressure, and aluminium - doped zinc oxide (ZnO:Al) transparent conducting film was deposited on PET substrate by r. f. magnetron sputtering method. Surface analysis and characterization of the plasma-treated PET substrate was carried out using contact angle measurements, X-ray Photoelectron Spectroscopy(XPS) and Atomic Force Microscopy (AFM). Especially the effect of surface state of PET substrate on some important properties of ZnO:Al transparent conducting film such as electrical and morphological properties and deposition rate of the film, was studied experimentally. The results showed that the contact angle of water on PET film was reduced significantly from $62^{\circ}$ to $43^{\circ}$ by DBD surface treatment at 20 min. of treatment time. The plasma treatment also improved the deposition rate and electrical properties. The deposition rate was increased almost linearly with surface treatment time. The lowest electrical resistivity as low as $4.97{\times}10^{-3}[\Omega-cm]$ and the highest deposition rate of 234[${\AA}m$/min] were obtained in ZnO:Al film with surface treatment time of 5min. and 20min., respectively.

• ALGAE
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• 제30권3호
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• pp.183-195
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• 2015

The dinoflagellate genus Pelagodinium is genetically classified in distinct sub-clades and subgroups. However, it is difficult to determine whether this genetic diversity represents intra- or interspecific divergence within the genus since only the morphology of the type strain of the genus Pelagodinium, Pelagodinium bei, is available. An isolate associated with the genus Pelagodinium from Shiwha Bay, Korea, was recently cultured. This isolate was clustered with 3 to 4 strains from the Atlantic Ocean, Mediterranean Sea, and Indian Ocean. This cluster was distinct from the subgroup more closely associated with P. bei. The morphology of the isolate was analyzed using optical and scanning electron microscopy and was almost identical to that of P. bei except that this isolate had two series of amphiesmal vesicles (AVs) in the cingulum, unlike P. bei that has one series. When the pigment compositions of the isolate and P. bei were analyzed using high-performance liquid chromatography, these two strains had peridinin as a major accessory pigment and their pigment compositions were almost identical. In addition, the swimming behaviors of these two strains were very similar. The reexamination of the type culture of P. bei revealed two series in the cingulum as for the isolate. The new findings on the number of series of AVs in the cingulum, the pigment composition, and the swimming behaviors suggest that P. bei and the isolate are conspecific despite their genetic divergence. This study provides a basis to further understand the molecular classification within Pelagodinium combining genetic, morphological, pigment, and behavioral data.

• ALGAE
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• 제33권1호
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• pp.21-35
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• 2018

The phototrophic dinoflagellate genus Scrippsiella is known to have a worldwide distribution. Here, we report for the first time, the occurrence of Scrippsiella lachrymosa in Korean waters. Unlike the other stains of S. lachrymosa whose cultures had been established from cysts in the sediments, the clonal culture of the Korean strain of S. lachrymosa was established from motile cells. When the sulcal plates of S. lachrymosa, which have not been fully described to date, were carefully examined using scanning electron microscopy, the Korean strain of S. lachrymosa clearly exhibited the anterior sulcal plate (s.a.), right sulcal plate (s.d.), left sulcal plate (s.s.), median sulcal plate (s.m.), and posterior sulcal plate (s.p.). When properly aligned, the large subunit (LSU) rDNA sequence of the Korean strain of S. lachrymosa was ca. 1% different from those of two Norwegian strains of S. lachrymosa, the only strains for which LSU sequences have been reported. The internal transcribed spacer (ITS) rDNA sequence of the Korean strain of S. lachrymosa was also ca. 1% different from those of the Scottish and Chinese strains and 3% different from those of the Canadian, German, Greek, and Portuguese strains. Thus, the Korean S. lachrymosa strain has unique LSU and ITS sequences. The abundances of S. lachrymosa in the waters of 28 stations, located in the East, West, and South Sea of Korea, were quantified in four seasons from January 2016 to October 2017, using quantitative real-time polymerase chain reaction method and newly designed specific primer-probe sets. Its abundances were >$0.1cells\;mL^{-1}$ at eight stations in January and March 2016 and March 2017, and its highest abundance in Korean waters was $26cells\;mL^{-1}$. Thus, S. lachrymosa has a nationwide distribution in Korean waters as motile cells.

• 한국미생물·생명공학회지
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• 제32권3호
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• pp.224-229
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• 2004

토양으로부터 강력한 CAH activity를 갖는 균주를 분리하여, 생화학적, 배양학적, 전자현미경 동정을 한 결과, Bacillus sphaericus로 확인되었으며, 이를 B. sphaericus 366M-9로 명명하였다. 또한 이 균으로부터 최초로 cephalosporin-C deacetylase(CAH)를 분리 정제하였다. 정제수율은 약 7.5% 였으며, B. sphaericus 366M-9에서 분리한 CAH-9의 최적활성 온도는 $50^{\circ}C$였으며, 효소안정 온도구간은 30～$50^{\circ}C$이다. 또한 최적 활성 pH는 7.0이었으며, 효소안정 pH구간은 pH 6.0～8.0으로 90% 이상의 잔존 활성도를 나타내었다. 효소반응속도에 미치는 기질의 영향에서는 $K_{m}$ 값은 0.87 mM 이며,$ V_{max}$는1.22 unit/ml이었다.다.