• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.556-557
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• 2001

생물 계면활성제의 개발을 위해 MNNG(N-Methyl-N-Nitro- NitrMoguanidjne), EMS, UV radiator 등 random mutation을 유도하여 가장 고기능 유화제 생산 균주를 선별하여 다양한 탄소원에 따른 생육도와 유화활성, 유화 활성에 미치는 pH 등 생물 계면활성제의 생산에 관한 조사를 한 결과 Bunker A에서는 유화활성이 원래 균주보다 최고 약 6배까지 증가했으며 표면장력 또한 40.3dyne/cm 에서 34.0dyne/cm 으로 크게 감소되었다.

• 한국수소및신에너지학회논문집
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• 제17권4호
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• pp.371-378
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• 2006

Effect of $(NH_4)_2SO_4$ precipitation and heat-treatment on hydrogenase which was extracted from the cytoplasmic fraction of the phototrophic purple sulfur bacterium Thiocapsa roseopersicina NCIB 8347 was studied. Crude enzyme extract was prepared by centrifugation($28,000{\times}g$, $400,000{\times}g$) after sonication of cells grown under photosynthetic condition for 96 hrs. Various conditions of $(NH_4)_2SO_4$ precipitation and heat-treatment were examined and the effect of protein concentration was analyzed by SDS-electrophoresis between the treatments. Optimum conditions for $(NH_4)_2SO_4$ precipitation and heat-treatment for evolution hydrogenase activity were 40-60% saturation and $60^{\circ}C$ for 20 min, respectively, which exhibited the specific hydrogenase activity of 0.78 U/mg-protein. Specific hydrogenase activity was decreased to 31.6% when the heat-treatment at $60^{\circ}C$ increased from 20 min to 5 hrs.

• 대한세포병리학회지
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• 제3권2호
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• pp.82-89
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• 1992

Electron microscopy (EM) can provide a valuable contribution to light microscopy (LM) In the Interpretation of fine needle aspiration cytology (FNAC) specimen, especially in the diagnosis of the tumor. However, considerable care in processing the specimen is mandatory to recover the cells and avoid altering the fine structures. We experienced a case of malignant melanoma in 33-yrs-old female, diagnosed by EM study of FNAC specimen from the axillary mass, who was initially thought as disseminated carcinomatosis on LM study. The technique of EM study on FNAC specimen consisted of washing the needle and syringe in 2.5% glutaraldehyde after a rapid stain (Diff-Quik), which was used to obtain a preliminary diagnostic impression and to assure the adequacy of the EM specimen. After centrifugation in the steps of fixation and dehydration, the sediment was made into an epon block and examined. The whole processing time of EM study can be shortened within 7 or 8 hours, and results can be available within 48 to 72 hours. Our experience suggests the EM study on FNAC can be a useful diagnostic method in the diagnosis of difficult FNAC cases.

• ALGAE
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• 제28권1호
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• pp.121-129
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• 2013

Intact phycobilisomes from a wild-type red Chondrus crispus and its vegetatively derived green mutant were isolated by centrifugation through a discontinuous sucrose density gradient. Pigment composition was subsequently characterized by spectrophotometry. Vegetative thalli of the two strains grown together for six months in the laboratory resulted in different pigment profiles. Two pigmented phycobilisome bands appeared in the sucrose gradient of the wild-type alga, a purple coloured one, and a pink one, whereas only a single blue band appeared in the gradient of the green mutant. Spectrophotometric and fluorescence analyses identified the phycobiliprotein composition of the purple band as the typical phycoerythrin-phycocyanin-allophycocyanin complement in the wild-type, but there was no detectable phycoerythrin present in the blue band of the green mutant. Sodium dodecyl sulphate, preparative polyacrylamide gel electrophoresis analysis confirmed the presence of allophycocyanin subunits in all extracts, but firm evidence of an R-phycoerythrin linker polypeptide in the blue band was missing. These results highlight the ability of C. crispus to adapt to a phycoerythrin deficiency by adjusting light harvesting pigment ratios.

• 한국물환경학회지
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• 제28권1호
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• pp.50-56
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• 2012

In this study, loess composites, loess with lanthanum and with aluminum, were made and evaluated for treatment of phosphorus removal in natural water system. Desiccation method for production of loess composite was superior to centrifugation method in obtaining high concentrated composites of lanthanum and aluminum. Washing of loess lanthanum composite by water did not deteriorat the lanthanum concentration in the composite, but this lowered the aluminum concentration of loess aluminum composite. Total of 15 and 37.5% of aluminum contents were removed after first washing treatment in aluminum loess of 0.05% and 0.1% respectively. However, no more aluminum loss was monitored with increase of washing times. Phosphorus removal efficiencies were not decreased with washed loess aluminum composite. Phosphorus removal was successfully achieved by adsorption of phosphate to loess composite at pH range of 5.0 ~ 8.0. Freundlich and Langmuir adsorption isotherm was observed in the adsorption of phosphate for loess composite. Dosages of 0.05% and 0.1% lanthanum composite for 95% of phosphorus removal could reduce its usage amount to 25% and 50%, respectively, comparing with dosage of loess alone. Dosages of 0.05% and 0.1% aluminum composite could reduce its usage amount to 48% and 63%, respectively.

• 펄프종이기술
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• 제41권5호
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• pp.26-32
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• 2009

As a part of utilizing the nanocellulose (NC) from lignocellulosic components of wood biomass, this paper reports preliminary results on the products of sulfuric acid hydrolysis. The purpose of this study was to investigate the morphology of both NC and micro-sized cellulose fiber (MCF) isolated by acid hydrolysis from commercial microcrystalline cellulose (MCC). Field emission.scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) were employed to observe the acid hydrolysis suspension, NC, and MCF. The electron microscopy observations showed that the acid hydrolysis suspension, before separation into NC and MCF by centrifugation, was composed of nano-sized NCs and micro-sized MCFs. The morphology of isolated NCs was a whisker form of rod-like NCs. Measurements of individual NCs using TEM indicated dimensions of 6.96$\pm$0.87 nm wide by 178$\pm$55 nm long. Observations of the MCFs showed that most of the MCC particles had de-fibered into relatively long fibers with a diameter of 3-9 ${\mu}m$, depending on the degree of acid hydrolysis. These results suggest that proper technologies are required to effectively realize the potentials of both NCs and MCFs.

• Journal of Microbiology
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• 제42권3호
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• pp.228-232
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• 2004

In this paper, we investigated the development of a simplified and rapid primary capture step for the recovery of M13 bacteriophage from particulate-containing feedstock. M13 bacteriophage, carrying an insert, was propagated and subsequently purified by the application of both conventional multiple steps and expanded bed anion exchange chromatography. In the conventional method, precipitation was conducted with PEG/NaCl, and centrifugation was also performed. In the single step expanded bed anion exchange adsorption, UpFront FastLine$\_$TM/20 (20mm i.d.) from UpFront Chromatography was used as the contactor, while 54$m\ell$ (H$\_$o/=15cm) of STREAMLINE DEAE (p=1.2 g/㎤) from Amersham Pharmacia Biotechnology was used as the anion exchanger. The performance of the two methods were evaluated, analysed, and compared. It was demonstrated that the purification of the M13 bacteriophage, using expanded bed anion exchange adsorption, yielded the higher recovery percentage, at 82.86％. The conventional multiple step method yielded the lower recovery percentage, 36.07％. The generic application of this integrated technique has also been assessed.

• BMB Reports
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• 제28권2호
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• pp.129-137
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• 1995

The ryanodine-receptor $Ca^{2+}$ release channel protein in the sarcoplasmic reticulum membrane of rabbit skeletal muscle plays an important role in muscle exitation-contraction (E-C) coupling. Various types of detergents were tested, including Chaps, cholate, octylglucoside, Zwittergents, Mega-9, Lubrol PX, and Triton X-100 for solubilization of this protein. Among these, Chaps and Triton X-100 were found to optionally solubilize the channel complex. Optimum conditions for this solubilization were pH 7.4 with a salt concentration of 1 M. The addition of phospholipid in the solubilization step helped in stabilizing the protein. The purification of the receptor was performed using sucrose density gradient centrifugation. Various methods [dilution, freeze-thaw, adsorption (Biobeads), and dialysis] were investigated to incorporate the Chaps-solubilized and purified $Ca^{2+}$ release channel protein into liposomes made from different types of phospholipids. Of these, a combined method consisting of a dialysis, freeze-thaw and sonication steps yielded the best results. Reconstituted vesicles produced by this method with 95% phosphatidylcholine (from soybean extract) had good function.

• 한국가금학회지
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• 제19권1호
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• pp.13-16
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• 1992

마사츄셋형 전염성 기관지염 바이러스(IBV)를 SPF 발육란의 뇨막강내에서 증식시켜 Sucrose 밀도구배 초원심분리에 의해 정제한 다음 BALB/c 마우스에 면역시켰다. 면역 마우스에서 채취한 비장세포와 마우스 골수암세포와 여러 차례 융합시험을 실시하였다. 많은 융합세포 중에서 IBV에 특이적으로 작용하는 단클론항체(monoclonal antibody ： MCA)를 산생하는 hybridoma클론은 2주밖에 얻지 못했다. 2주의 MCA는 모두 IgG형이었고 IBV중화능이나 혈구응집 억제능이 인정되지 않았다. 간접형광항체법으로 작성된 MCA를 이용하여 인공접종한 닭의 기관도말표본에서 10일간의 시험기간중 계속 IBV를 검출할 수 있었다.

• BMB Reports
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• 제39권4호
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• pp.426-431
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• 2006

Embryonic stem cells (ESCs), representing a population of undifferentiated pluripotent cells with both self-renewal and multilineage differentiation characteristics, are capable of spontaneous differentiation into cardiomyocytes. The present study sought to define the kinetic characterization of lactate dehydrogenase (LDH) and creatine kinase (CK) of ESC- and neonatal-derived cardiomyocytes. Spontaneously differentiated cardiomyocytes from embryoid bodies (EBs) derived from mouse ESC line (Royan B1) and neonatal cardiomyocytes were dispersed in a buffer solution. Enzymes were extracted by sonication and centrifugation for kinetic evaluation of LDH and CK with spectrophotometric methods. While a comparison between the kinetic properties of the LDH and CK of both groups revealed not only different Michaelis constants and optimum temperatures for LDH but also different Michaelis constants and optimum pH for CK, the pH profile of LDH and optimum temperature of CK were similar. In defining some kinetic properties of cardiac metabolic enzymes of ESC-derived cardiomyocytes, our results are expected to further facilitate the use of ESCs as an experimental model.