• Journal of Microbiology and Biotechnology
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• 제20권1호
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• pp.110-116
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• 2010

Lactic acid (LA) fermentation by Lactobacillus salivarius ATCC 11741 immobilized on loofa sponge (LS) was evaluated. To increase the surface area of LS for cell immobilization, $H_2O_2$ and chitosan were introduced as surface modifying reagents. Four chitosans of different molecular weights were separately coated on LS. All experiments were conducted in shaking flask mode at 100 rpm rotating speed and $37^{\circ}C$ with 5% $CaCO_3$ as a pH regulating agent. The effects of initial glucose concentration were investigated in the range of 20-100 g/l on LA fermentation by free cells. The results indicate that the maximum concentration of LA was produced with 50 g/l glucose concentration. The immobilized cell system produced 1.5 times higher concentration than free cells for 24 h of fermentation. Moreover, immobilized cells can shorten the fermentation time by 2-fold compared with free cells at the same level of LA concentration. At 1% (w/v) chitosan in 2% (v/v) acetic acid, the Yp/s and productivities of various molecular weights of chitosans were insignificantly different. Repeated batch fermentations showed 5 effective recycles with Yp/s and productivity in the range of 0.55-0.85 and 0.90-1.20 g/l.h, respectively. It is evident that immobilization of L. salivarius onto LS permits reuse of the system under these fermentation conditions. Scanning electron micrographs indicated that there were more intact cells on the chitosan-treated LS than on the untreated LS, thus confirming the effectiveness of the LS-chitosan combination when being utilized as a promising immobilization carrier for LA fermentation.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.249-254
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• 1997

ABA-type block copolymers composed of poly(L-leucine)(PLL) as the A component and poly(ethylene glycol)(PEG) as the B component were synthesized by ring-opening polymerization of L-leucine N-carboxyanhydride initiated by primary amino group located at both ends of PEG chain. A silver sulfadiazine(AgSD)-impregnated wound dressing of sponge-type was prepared by the lyophilization method. Morphological structure of this wound dressing obtained by scanning electron microscopy(SEM) was composed of a dense skin layer and a macroporous inner sponge layer. Equilibrium water content(EWC) of wound dressing was above 10%. It increased with an increased of PEO content in the block copolymer due to the hydrophilicity of PEO. AgSD release from AgSD- impregnated wound dressing in PBS buffer(pH=7.4) was dependent on PEG composition in the block copolymer. Therefore, EWC and release of AgSD can be control by PEG composition. Antibacterial capacity of AgSD-impregnated wound dressing was examined in agar plate against Pseudmonas aeruginosa and Stapplococus aruous. Cytotoxicity of the wound dressing was evaluated by studing mouse skin fibroblast(L929). From the behavior of antimicrobial releasing and the investigation of the suppression of bacterial proliferation, it was supposed that the wound dressing containing antibiotics could protect the wound surfaces from bacterial invasion to suppress the bacterial proliferation effectively. In cytotoxicity observation, cellular damage was reduced by the control led released of AgSD from the LEL sponge matrix of AgSD-medicated wound dressing. In vivo test, granulous tissue formation and wound contraction or the AgSD and DHEA impregnated wound dressing were aster than any other groups.

• 한국해양바이오학회지
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• 제1권4호
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• pp.243-251
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• 2006

Dideoxypetrosynol A, a polyacetylene from the marine sponge Petrosia sp., is known to exhibit significant selective cytotoxic activity against a small panel of human tumor cell lines, however, the mechanisms of which are poorly understood. In the present study, it was investigated the further possible mechanisms by which dideoxytetrosynol A exerts its anti-proliferative action in cultured human leukemia cell line U937. We observed that the proliferation-inhibitory effect of dideoxypetrosynol A was due to the induction of G1 arrest of the cell cycle and apoptosis, which effects were associated with up-regulation of cyclin D1 and down-regulation of cyclin E without any change in cyclin-dependent-kinases (Cdks) expression. Dideoxypetrosynol A markedly induced the levels of Cdk inhibitor p16/INK4a expression. Furthermore, down-regulation of phosphorylation of retinoblastoma protein (pRB) by this compound was associated with enhanced binding of pRB and the transcription factor E2F-1. The increase in apoptosis was associated with a dose-dependent up-regulation in pro-apoptotic Bax expression and activation of caspase-3 and caspase-9. Dideoxytetrosynol A decreased the levels of cyclooxygenase (COX)-2 mRNA and protein expression without significant changes in the levels of COX-1, which was correlated with a decrease in prostaglandin E2 (PGE2) synthesis. Furthermore, dideoxytetrosynol A treatment markedly inhibited the activity of telomerase, and the expression of human telomerase reverse transcriptase (hTERT), a main determinant of the telomerase enzymatic activity, was progressively down-regulated by dideoxytetrosynol A treatment in a dose-dependent fashion. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of dideoxytetrosynol A.

• 한국재료학회지
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• 제20권8호
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• pp.418-422
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• 2010

As a starting material, BCP (biphasic calcium phosphate) nano powder was synthesized by a hydrothermal microwave-assisted process. A highly porous BCP scaffold was fabricated by the sponge replica method using 60 ppi (pore per inch) of polyurethane sponge. The BCP scaffold had interconnected pores ranging from $100\;{\mu}m$ to $1000\;{\mu}m$, which were similar to natural cancellous bone. To realize the antibacterial property, a microwave-assisted nano Ag spot coating process was used. The morphology and distribution of nano Ag particles were different depending on the coating conditions, such as concentration of the $AgNO_3$ solution, microwave irradiation times, etc. With an increased microwave irradiation time, the amount of coated nano Ag particles increased. The surface of the BCP scaffold was totally covered with nano Ag particles homogeneously at 20 seconds of microwave irradiation time when 0.6 g of $AgNO_3$ was used. With an increased amount of $AgNO_3$ and irradiation time, the size of the coated particles increased. Antibacterial activities of the solution extracted from the Ag-coated BCP scaffold were examined against gram-negative (Escherichia coli) and gram-positive bacteria (Staphylococcus aureus). When 0.6 g of $AgNO_3$ was used for coating the Ag-coated scaffold, it showed higher antibacterial activities than that of the Ag-coated scaffold using 0.8 g of $AgNO_3$.

• 미생물학회지
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• 제46권3호
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• pp.255-261
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• 2010

남태평양에 서식하는 두 종의 해면 Hyrtios sp. 604와 Callyspongia sp. 612로부터 16S rDNA DGGE 방법을 이용하여 공생세균 군집의 다양성을 분석하였다. DGGE band로부터 염기서열 분석 결과, Hytrios sp. 604의 공생세균은 Alphaproteobacteria, Gammaproteobacteria, Acidobacteria, Actinobacteria, Chloroflexi, Cyanobacteria, Firmicutes로 나타났으며, Callyspongia sp. 612의 공생세균 그룹은 Alphaproteobacteria, Gammaproteobacteria, Chloroflexi, Cyanobacteria로 나타났다. 풍부한 이차대사산물의 생산자로 보고된 Hyrtios 해면 속의 Hyrtios sp. 604는 Callyspongia sp. 612에 비해 더 다양한 공생세균 군집을 나타내었으며 주요 공생세균 군집으로 Actionobacteria가 포함되었다. 동일 지역에 서식하나 화학적 특성이 다른 두 해면 종의 세균 군집은 서로 다른 것으로 나타났다. 발견된 공생세균의 염기서열은 90% 이상이 uncultured clone들과 높은 상동성을 나타내었다.

• 한국해양바이오학회지
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• 제6권2호
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• pp.76-83
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• 2014

할로겐화 또는 탈할로겐화에 관여하는 미생물을 특정하고자 해양의 주된 할로겐화합물 생산자인 해면 공생미생물의 군집구조에 미치는 HBB (hexabromobenzene)의 영향을 밝히고자 했다. 혐기 marine broth 2216에서 100ppm HBB첨가 유무에 관계없이 검출된 균주들은 산호나 해면에서 유래한 클론들과 높은 유사도를 보였으며 그 중 Deltaproteobacteria에 속하는 Desulfovibrio marinisediminis와 99% 유사도를 보이는 클론이 우점하는 것으로 나타났다. Clostridia계통의 Fusibacter paucivorans와 유사도가 높은 클론과 Lentisphaerae에 속하는 균주들은 HBB에 의해 감소하는 반면 Clostridia계통의 Vallitalea guaymasensis와 유사도가 높은 균주들은 HBB가 있는 경우에만 검출되었다. 알려진 균주들과의 비교 결과로 볼 때 D. marinisediminis 및 V. guaymasensis 계통의 균주들이 할로겐화 및 탈할로겐화에 관여하는 것으로 추정된다.

• 대한방사선기술학회지:방사선기술과학
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• 제46권6호
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• pp.485-491
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• 2023

As an auxiliary tool for fixing the patient's posture when taking an X-ray, sponges with high radiolucencies are laminated in various thicknesses. This study aimed to evaluate the usefulness of an auxiliary tool for hand oblique projection X-ray by manufacturing it with a uniform thickness by 3D printing and comparing it with existing sponge tools. In the auxiliary tool, radiolucency was measured at the stairs where each finger was located, and pixel information values were compared in the digital imaging and communications in medicine(DICOM) image. Contrast to noise ratio(CNR) and signal to noise ratio(SNR) were compared by shooting the hand phantom and the auxiliary tool together. As the thickness of the sponge tool increased, radiolucency decreased by 15.52% and pixel information value increased by 20.61%. The transmittance of the 3D printing tool increased by 0.82%, and the pixel information value differed by 5.66%. CNR and SNR increased by 20.03% and 22.42% in 3D printing compared to existing sponge tools. while taking hand oblique projection, maintaining the thickness of the auxiliary tool uniformly through 3D printing maintains high radiolucency and minimal impact on medical images, and increases CNR and SNR, making it useful as an auxiliary tool for taking hand oblique projection.

• Clinical and Experimental Vaccine Research
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• 제12권1호
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• pp.70-76
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• 2023

Purpose: Typhoid remains a major health problem, especially in the developing world. Furthermore, the emergence of multidrug-resistant and extensively drug-resistant strains of Salmonella typhi added a sense of urgency to develop more effective typhoid vaccines, one of which is bacterial ghosts (BGs), prepared by both genetic and chemical means. The chemical method includes incubation with numerous agents for a short time at their minimum inhibitory or minimum growth concentrations. This study included the preparation of BGs by a sponge-like reduced protocol (SLRP). Materials and Methods: Critical concentrations of sodium dodecyl sulfate, NaOH, and H₂O₂ were used. Moreover, high-quality BGs were visualized by scanning electron microscope (SEM). Subculturing was used to confirm the absence of vital cells. Besides, the concentrations of the released DNA and protein were estimated spectrophotometrically. In addition, the integrity of cells was proved by visualizing Gram-stained cells using a light microscope. Furthermore, a comparison between the immunogenicity and safety of the prepared vaccine and the available whole-cell killed vaccine was established. Results: Improved preparation of high-quality BGs of S. typhi, visualized by SEM, revealed punctured cells with intact outer shells. Moreover, the absence of vital cells was confirmed by subculturing. At the same time, the release of respective amounts of proteins and DNA is another evidence of BGs' production. Additionally, the challenge test provided evidence that the prepared BGs are immunogenic and have the same efficacy as the whole cell vaccine. Conclusion: The SLRP provided a simple, economical, and feasible method for BGs preparation.

• 한국식품조리과학회지
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• 제8권4호
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• pp.371-378
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• 1992

미분의 품종별(한강 찰벼, 추청 일반벼, 태백 통일벼), 제분 방법별(건식제분, 습식제분), 입도별(whole, 60mesh 이상, 100mesh 이상)등 미분의 특성이 스폰지 케이크의 제빵성에 미치는 영향을 조사하였다. $150^{\circ}C$에서 34분간 굽는 동안 반죽의 높이는 14~18분경 최대에 달했으며 그후 점차 감소하였다. 구운지 1일후 케이크의 높이는 반죽의 최대높이의 6~50%로 감소하였다. 굽는 과정중 반죽 내부의 온도는 서서히 증가하여 8~10분경 그 증가율이 가장 컸으며, 이때의 온도는 $60^{\circ}C$전후이었다. 100g의 반죽으로 만든 케이크의 체적은 제분 방법이나 미분의 입도에 따른 차이가 없이 밀가루로 만든 케이크 체적 100에 대하여 89~95로서 미분 100% 케이크 제조가 가능하였다. 한강의 체적은 80으로서 구운후 수축이 심하였다. 케이크의 경도는 미분의 종류, 미분의 입도에 무관하게 습식제분의 케이크가 건식제분의 것보다 낮았다. 태백의 건식제분 100mesh로 제조된 케이크의 경도와 응집성은 밀가루 스폰지 케이크에 근사하였다. 케이크의 관능검사 결과 texture나 맛면에서 전반적으로 건식제분보다는 습식제분의 케이크가 월등히 우수하였다. 특히, amylopectin 함량이 낮은 태백의 습식제분으로 제조된 케이크는 미분의 입도와는 관계없이 밀가루로 만든 것보다 관능평가 결과가 우수하였다.

• 한국생활과학회지
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• 제21권3호
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• pp.577-586
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• 2012

본 연구에서는 키토산 첨가가 스폰지 케이크의 품질에 미치는 영향을 위하여 키토산을 세 가지 농도(1,000, 2,000, 3,000 ppm)로 첨가하여 제조한 스폰지 케이크를 $5^{\circ}C$, $15^{\circ}C$ 및 $25^{\circ}C$에 5일간 저장하여 저장 중 일어나는 품질변화, 노화도, 색도 변화 및 관능평가를 측정하여 품질 특성에 대하여 조사하였다. Hardness는 키토산 첨가한 시료가 대조구에 비해 조직이 부드러웠고, gumminess와 chewiness도 대조구에 비해 낮은 값을 나타내고, 키토산을 첨가한 시료들간의 차이는 나타나지 않았다. 키토산을 함유한 스폰지 케이크의 노화도는 대조구에 비해 상대적으로 높은 것으로 나타났으며, 그 값은 키토산의 첨가농도 및 저장조건에 관계없이 약 30% 이내로 작게 나타났다. 저장온도에 대한 노화 진행 정도를 속도론적 관점에서 분석한 결과 키토산을 함유한 시료의 경우 대조구에 비해 느리게 노화가 진행되어 상대적으로 저장온도의 영향을 작게 받는 것으로 분석되었다. 키토산을 함유한 시료군들의 명도(lightness, a value)는 대조구에 비하여 높은 값을 보였으며, 2,000ppm과 3000 ppm 농도로 첨가한 시료군들의 명도는 유의적으로 증가하여 대조구의 71.49에 비해 높은 74.23 및 73.57의 값을 나타내었다. 적색도(redness, a value)의 경우는 키토산을 첨가한 시료군들의 값이 대조구에 비해 감소하는 것으로 나타났으며, 키토산을 1,000 ppm 수준으로 첨가한 시료가 가장 낮은 -4.88의 값을 나타내었다. 그리고 황색도(yellowness, b value)는 키토산의 첨가농도에 따라 일정한 경향을 보이지 않았다. 키토산을 첨가한 시료군들과 대조구와의 색차(Total color difference, E)의 경우 키토산의 첨가농도에 따른 색차의 값은 유의차가 없는 것으로 나타났다. 전체적인 선호도를 살펴보면, 키토산은 2,000 ppm의 농도까지 첨가하여 제조한 스폰지 케이크는 대조구와 유의적 차이를 보이지 않았다.