• Journal of Microbiology and Biotechnology
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• 제23권6호
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• pp.864-871
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• 2013

The recombinant strain P. pastoris GS115-lccC was used to produce laccase with high activity. Factors influencing laccase expression, such as pH, methanol concentration, copper concentration, peptone concentration, shaker rotate speed, and medium volume were investigated. Under the optimal conditions, laccase activity reached 12,344 U/L on day 15. The recombinant enzyme was purified by precipitating and dialyzing to electrophoretic homogeneity, and was estimated to have a molecular mass of about 58 kDa. When guaiacol was the substrate, the laccase showed the highest activity at pH 5.0 and was stable when the pH was 4.5~6.0. The optimal temperature for the laccase to oxidize guaiacol was $60^{\circ}C$, but it was not stable at high temperature. The enzyme could remain stable at $30^{\circ}C$ for 5 days. The recombinant laccase was used to degrade chlorpyrifos in several laccase/mediator systems. Among three synthetic mediators (ABTS, HBT, VA) and three natural mediators (vanillin, 2,6-DMP, and guaiacol), vanillin showed the most enhancement on degradation of chlorpyrifos. Both laccase and vanillin were responsible for the degradation of chlorpyrifos. A higher dosage of vanillin may promote a higher level of degradation of chlorpyrifos, and the 2-step addition of vanillin led to 98% chlorpyrifos degradation. The degradation of chlorpyrifos was faster in the L/V system ($k_{obs}$ = 0.151) than that in the buffer solution ($k_{obs}$ = 0.028).

• Journal of Plant Biotechnology
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• 제5권1호
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• pp.33-41
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• 2003

Microspore-derived cell lines resistant to 5-methyltryptophan (5MT, a tryptophan analog) or S-(2-aminoethyl)-L-cysteine (AEC, a Iysine analog) were selected in rice by in vitro mutagenesis. For selection of 5MT or AEC resistant cell lines, suspension-cultured cells were irradiated with gamma rays. Thirteen 5MT resistant cell lines were selected and they were able to grow stably at 2 times higher 5MT concentration. A feedback insensitive form of anthranilate synthesis, the pathway specific control enzyme for tryptophan synthesis, was detected from the 5MT resistant lines. Contents of the free amino acids in five resistant lines (MR12-1 to MR12-5) showed a 7.4 to 46.6 times greater level than that in the control culture. Tryptophan, phenylalanine, and tyrosine levels in the shikimate pathway were 28.1 and 22.5 times higher in MR12-3 and MR12 4, respectively, than that measured in the control cells. Four AEC resistant cell lines were isolated from cultures grown on medium containing 1 mM AEC, They were able to grow stably with 2 mM AEC, while sensitive calli were inhibited by 0.5 mM AEC. Aspartate kinase activities of the resistant lines were insensitive to the natural inhibitor, Iysine, and accumulated 2.2 to 12.9-fold higher levels of free Iysine than that of the control cells. Especially, the levels of aspartate, asparagine, and methionine in the aspartate pathway showed higher accumulation in the AEC resistant lines than that in the control cells.

• 식물병연구
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• 제12권1호
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• pp.46-50
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• 2006

비경작 산림 토양으로부터 고추역병 억제와 초기생육 촉진 효과를 보이는 방선균을 분리하였다. 분리된 Streptomyces griseofuscus 200401은 역병균 뿐만 아니라 탄저병에 대하여 항균활성을 보였다. 분리 미생물 배양액과 그 제제의 생육초기단계 처리로 식물체의 엽수, 생물 중 및 건물 중 등이 대조구에 비해 증가하였다. 공시균주 배양액 중 유기질소원의 분해에 의한 ammonium chloride의 농도는 배양 후 0.13 ${\mu}g/ml$로 나타났다. 분리균주의 온실에서 고추역병 발생억제 효과를 검정한 결과, 1주일 간격으로 3회 처리한 경우 최종방제가가 37.3%로 대조약제와 유사하게 나타났다.

• 상하수도학회지
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• 제29권1호
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• pp.47-55
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• 2015

Recently, the production of taste and odor (T&O) compounds is a common problem in water industry. Geosmin is one of the T&O components in drinking water. However, geosmin is hardly eliminated through the conventional water treatment systems. Among various advanced processes capable of removing geosmin, adsorption process using granular activated carbon (GAC) is the most commonly used process. As time passes, however GAC process changes into biological activated carbon (BAC) process. There is little information on the BAC process in the literature. In this study, we isolated and identified microorganisms existing within various BAC processes. The microbial concentrations of BAC processes examined were $3.5{\times}10^5$ colony forming units (CFU/g), $2.2{\times}10^6CFU/g$ and $7.0{\times}10^5CFU/g$ in the Seongnam plant, Goyang plant and Goryeong pilot plant, respectively. The dominant bacterial species were found to be Bradyrhizobium japonicum, Novosphingobium rosa and Afipia broomeae in each plants. Removal efficiencies of $3{\mu}g/L$ geosmin by the dominant species were 36.1%, 36.5% and 34.3% in mineral salts medium(MSM) where geosmin was a sole carbon source.

• 한국식품과학회지
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• 제17권2호
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• pp.81-88
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• 1985

자연계로 부터 지질생산 균주, Penicillium sp.을 분리하였다. 이 균의 최적 지질생산 조건은 탄소원으로 포도당 6%, 질소원으로 ammonium nitrate, 배양기간 17일, C:N ratio 200, 배양 초기pH 4.0, 진탕배양(100 rpm), $35^{\circ}C$이었고 이때 생산된 균체량은 2.26g/200ml, 지질함량은 64.2%. 지질생성률 13.7g이었다. 최적 지질생산 조건에서 생산된 지질 중에 비극성 지질의 함량은 92.2%, 극성 지질은 7.8%이었다. 비극성 지질의 조성은 free fatty acid, free sterol, partical glyceride, triglyceride이며 이들중 triglyceried가 72.0%로 대부분을 차지하고 있다. 총지질의 주요 지방산은 oleic acid 53.3%, linoleic acid 21.6%, plamitic acid 20.1%로 oleic acid가 가장 많이 존재하며 이들 주요 지방산이 전체 지방산의 90%이상을 차지하고 있다. 식물성 유지인 땅콩 olive oil의 지방산 조성과 비슷한 경향을 나타내고 있다.

• Applied Biological Chemistry
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• 제40권3호
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• pp.173-177
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• 1997

Bacillus licheniformis 9945a는 액체배양시 ${\gamma}-poly(glutamic\;acid)$를 균체외로 분비하며, 한천배지에 고체 배양시는 점액질의 군락을 나타낸다. 점액질의 Bacillus속 세균의 형질전환은 그리 순하지 않은 것으로 알려져 있으며, B. licheniformis에서의 trasposon Tn10의 활성여부도 알려져 있지 않다. 그래서 점액질을 분비하지 않는, B. licheniformis의 자연발생적 변이주를 우선 분리하였다. Mini-Tn10을 함유한 plasmid pHV1248을 protoplast transformation법에 준해서 이 변이주에 도입하여 형질전환체를 분리하였다. pHV1248을 함유한 형질전환체를 점액성의 야생형질로 복귀시킨 후에, 가열처리함으로써 무작위 돌연변이를 유도하였다. Arginine, lysine 또는 tryptohan을 생육인자로 요구하는 돌연변이주들이 replica plating method에 의해서 분리되었고, 이 들 영양요구성 변이주는 mini-Tn10이 염색체 DNA상에 삽입됨으로써 생겨났음이 Southern blotting과 DNA-DNA 혼성화 실험으로 증명되었다. 이러한 pHV1248을 이용한 형질전환 및 돌연변이 유도방법은 Bacillus licheniformis 9945a의 다양한 변이체를 얻는데 유용할 것이다.

• 한국광물학회지
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• 제2권1호
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• pp.26-36
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• 1989

Clinopyroxene in the Geodo mine belongs to diopside-hedenbergite series. It is widely distributed throughout the mine area together with garnet and is also closely related with Fe-mineralization. Clinopyroxenes in the Geodo mine including two samples from the sangdong and Ulchin Mines are studied using polarized microscope, EPMA, XRD, and IR spectroscopy for occurrence, chemistry, structure, and crystal chemistry. Especially, variations in unit-cell parameters are examined in relation with the substitution scheme between Fe and Mg cations. Clinopyroxenes in the Geodo mine occur in both endoskarn and exoskarn zone. It is mostly anhedral to subhedral with fine- to medium-grained in texture, but some have bigger crystals of short prismatic or columnar habits. Clinopyroxene occurs as monomineralic or is associated with mostly garnet and sometimes with actinolite, magnetite, epidote, and chlorite. Chemical analysis reveals that the Geodo clinopyroxene is diopsidic in composition (Di: 65-96%). This fact is in good contrast with garnet chemistry showing mostly andraditic (An: 41-82%). Especially, clinopyroxene coexisting with magnetite belongs to nearly end member diopside (Di: 97-99%). Thus, diopside-andradite pair indicates that Geodo skarns were formed under the reduced environment. X-ray diffraction analysis shows unit-cell parameters vary with increase of Fe contents: a = 9.765-9.838$\AA$, b = 8.943-9.020$\AA$, c= 5.240-5.253$\AA$.$\beta$ = 105.70-104.83$^{\circ}$, and V =440.64-448.19$\AA$3. It is noted from the least square regression that a, b and V increase linearly with increase of Fe content, while $\beta$ slightly decreases and c remains nearly unchanged as change in Fe content. These trends are to difference between synthetic and natural clinopyroxenes. This fact is also recognized in IR spectra which show a slight shift of several absorption bands toward lower wavenumber region with increasing Fe content.

• 원예과학기술지
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• 제29권3호
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• pp.201-210
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• 2011

This experiment was conducted to investigate physical and chemical characteristics by volume fractions of root media using peatmoss, perlite, and vermiculite, along with effects on the growth of pot chrysanthemums (Dendranthema ${\times}$ grandiflorum 'Vemini') in a C-channel mat irrigation system. To evaluate the physico-chemical properties of 20 root media, the bulk density, particle density, total pore space, pore space, ash content, organic matter, pH, and electrical conductivity were measured and data were analyzed using principal component analysis (PCA). PCA scores revealed that physico-chemical properties changed by the blending of peatmoss, perlite, and vermiculite. The 20 root media were divided into three main groups by hierarchical cluster analysis. At the end of the experiment, the pH and EC of the root media were measured from media divided into four layers. The pH of root media without plants showed a strong linear relationship and the pH of root media with plants increased exponentially. The change of EC in the root medium was indicated as a hyperbolic curve. Plant growth characteristics according to growth in the 20 root media were analyzed by PCA. It was found that the mixing ratios of the root media affected plant growth characteristics. Therefore, mixing ratio is an important factor for pot-plant production in a subirrigation system.

• Archives of Reconstructive Microsurgery
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• 제22권1호
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• pp.18-23
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• 2013

Purpose: For reconstruction of lower extremity defects, various flaps can be used and the appropriate flap must be selected and applied according to the size of the defect. In particular, in cases where the defect size is small to moderate, thinner or smaller volume flaps are useful. The authors performed reconstruction of small to moderate defects on the lower extremities using superficial circumflex iliac artery perforator free flaps and are reporting the results. Materials and Methods: Fifteen patients underwent reconstruction of defects on lower extremity areas using superficial circumflex iliac artery perforator free flaps from July 2011 to July 2012 at this hospital. The flaps were elevated from above the deep fat layer, and, in all cases, the vessel diameter of the flaps was less than 1mm, with the exception of superficial vein that accompanied it. Results: The mean follow up period was 4.46 months, and, despite a partial loss in the flap in two cases, there were no total losses. All donor sites were closed with primary closure, and there was no occurrence of complications, such as hematomas, seromas, or lymphorrheas. The patients were highly satisfied with the donor site scar since it could be masked by underwear. Conclusion: Compared to other flaps, superficial circumflex iliac artery perforator free flaps are thinner in thickness and smaller in volume, which results in a more natural contour of the recipient site after the operation. In addition, since the flap can be elevated from supra-deep fat layer, the operation time can be shortened, and lymphorrhea can be prevented, which in turn lessens donor-site morbidity.

• 생명과학회지
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• 제20권6호
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• pp.902-906
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• 2010

고온성 균주로 알려진 Geobacillus 속의 다양한 균주로부터 내열성 extracellular lipase를 생산하는 G. kaustophilus DSM 7263를 선별하였다. 우리는 본 균주로부터 lipase를 대량생산하기 위한 최적 조건을 조사하였다. 배양 배지에 다양한 천연오일을 첨가한 결과, lipase의 최적 생장을 위한 탄소원으로는 0.5% 올리브 오일이 최적 조건으로 확인되었다. 본 균주의 생장을 위한 최적온도와 pH는 각각 $55^{\circ}C$와 8.0인 반면, lipase 생산을 위한 최적 온도와 pH는 각각 $50^{\circ}C$와 6.0을 나타내어 최적생육조건과는 다른 양상을 나타내었다. 금속이온에 대한 영향에 대해서는 배지에 $Mg^{2+}$과 $Mn^{2+}$을 첨가한 경우 각각 247%와 157%의 효소 생산이 증가한 반면, $Co^{2+}$, $Fe^{2+}$, $Ni^{2+}$, $Cu^{2+}$는 효소 생산을 저해 하였다. 또한 0.1% (v/v) triton X-100을 첨가하면 대조구에 비해 효소생산과 균의 생장이 모두 증가하는 것으로 나타났다.