• Journal of Microbiology
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• 제43권3호
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• pp.301-307
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• 2005

The feasibility of laccase production by immobilization of Pleurotus ostreatus 1804 on polyurethane foam (PUF) cubes with respect to media composition was studied in both batch and reactor systems. Enhanced laccase yield was evidenced due to immobilization. A relatively high maximum laccase activity of 312.6 U was observed with immobilized mycelia in shake flasks compared to the maximum laccase activity of free mycelia (272.2 U). It is evident from this study that the culture conditions studied, i.e. biomass level, pH, substrate concentration, yeast extract concentration, $Cu^{2+}$ concentration, and alcohol nature, showed significant influence on the laccase yield. Gel electrophoretic analysis showed the molecular weight of the laccase produced by immobilized P. ostreatus to be 66 kDa. The laccase yield was significantly higher and more rapid in the packed bed reactor than in the shake flask experiments. A maximum laccase yield of 392.9 U was observed within 144 h of the fermentation period with complete glucose depletion.

• Korean Chemical Engineering Research
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• 제45권5호
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• pp.473-478
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• 2007

공침법을 이용하여 질산은($AgNO_3$)을 수산화아파타이트(hydroxyapatite)에 흡착시켜 복합항균제를 제조하였다. 질산은의 농도, 온도, 압력, 숙성시간에 따른 흡착된 은이온양의 변화를 관찰하였고, 은-수산화아파타이트 흡착의 최적조건을 얻었다. 제조된 은-수산화아파타이트를 ICP-MS, SEM-EDAX, DSC, XRD를 이용하여 물리적 화학적 특성을 고찰하였다. 또한 제조된 은-수산화아파타이트는 진탕플라스크실험법(shake flask method, KS M-146-2003)을 이용하여 양성균인 황색포도상구균(staphylococcus aureus, ATCC 6538)과 음성균인 대장균(escherichia coli, ATCC 25922)의 항균성을 확인하였다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권6호
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• pp.459-464
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• 2004

The objective of this study is to improve cephalosporin C (CPC) production byoptimization of medium and culture conditions. A statistical method was introduced to optimize the main culture medium. The main medium for CPC production was optimized using a statistical method. Glucose and corn steep liquor (CSL) were found to be the most effective factors for CPC production. Glucose and CSL were optimized to 2.84 and $6.68\%$, respectively. CPC produc­tion was improved $50\%$ by feeding of $5\%$ rice oil at day 3rd and 5th day during the shake flask culture of C acremonium M25. The effect of agitation speeds on CPC production in a 2.5-L bio­reactor was also investigated with fed-batch mode. The maximum cell mass (54.5 g/L) was obtained at 600 rpm. However, the maximum CPC production (0.98 g/L) was obtained at 500 rpm. At this condition, the maximum CPC production was improved about $132\%$ compared to the re­sult with batch flask culture.

• 청정기술
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• 제23권4호
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• pp.401-407
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• 2017

본 연구에서 아카시아꽃잎을 기질로 미백효과와 항산화효과가 우수한 천연물질을 생산하는 플라스크 발효법을 개발하였다. 아카시아꽃잎 추출액은 tyrosinase 활성을 저해하지 않은 반면, 2년 전통발효액과 2년 전통발효액을 접종한 아카시아꽃잎 플라스크 발효액은 tyrosinase 활성을 저해하였다. 아카시아꽃잎 플라스크 발효농축액 10% 포함된 용액의 tyrosinase 활성 저해율은 40%였고 농축액 함량이 증가할수록 저해율도 증가하였다. 양성대조군인 알부틴($20mg\;mL^{-1}$)과 코직산($80{\mu}g\;mL^{-1}$)의 tyrosinase 활성 저해율은 각각 90%와 58%였다. 이는 플라스크 발효농축액 40%가 포함된 용액의 미백성능이 코직산($80{\mu}g\;mL^{-1}$)의 성능과 비슷함을 보여준다. 농축액이 20% 포함된 용액의 항산화활성은 56%였고 농도가 증가할수록 용액의 항산화활성도 점차 증가하여 농축액이 60% 포함된 용액의 항산화활성은 98%였다. 이는 항산화효과가 우수한 비타민 C 수용액($10mg\;mL^{-1}$)과 동일한 항산화능력이다. 모든 농도의 발효농축용액에서 95% 이상의 세포생존율을 나타내어 발효액은 독성이 없는 것으로 판명되었다. 실온에 보관된 아카시아꽃잎 발효상등액은 pH와 당도 변화가 없었고 분리, 변색, 및 변취 등의 관능적 성상의 변화가 없는 안정한 상태를 유지하였다. 본 결과는 아카시아꽃잎 플라스크 발효액이 안전하고 미백 및 항산화효과가 뛰어나 미백화장품 원료로 사용가능함을 보여준다. 이는 본 연구를 통하여 아카시아꽃잎 발효기간을 획기적으로 단축시킨 배양방법이 개발되었음을 시사한다.

• Journal of Microbiology and Biotechnology
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• 제27권1호
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• pp.101-111
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• 2017

The task of improving a fungal strain is highly time-consuming due to the requirement of a large number of flasks in order to obtain a library with enough diversity. In addition, fermentations (particularly those for fungal cells) are typically performed in high-volume (100-250 ml) shake-flasks. In this study, for large and rapid screening of itaconic acid (IA) high-yielding mutants of Aspergillus terreus, a miniaturized culture method was developed using 12-well and 24-well microtiter plates (MTPs, working volume = 1-2 ml). These miniaturized MTP fermentations were successful, only when highly filamentous forms were induced in the growth cultures. Under these conditions, loose-pelleted morphologies of optimum sizes (less than 0.5 mm in diameter) were casually induced in the MTP production cultures, which turned out to be the prerequisite for the active IA biosynthesis by the mutated strains in the miniaturized fermentations. Another crucial factor for successful MTP fermentation was to supply an optimal amount of dissolved oxygen into the fermentation broth through increasing the agitation speed (240 rpm) and reducing the working volume (1 ml) of each 24-well microtiter plate. Notably, almost identical fermentation physiologies resulted in the 250 ml shake-flasks, as well as in the 12-well and 24-well MTP cultures conducted under the respective optimum conditions, as expressed in terms of the distribution of IA productivity of each mutant. These results reveal that MTP cultures could be considered as viable alternatives for the labor-intensive shake-flask fermentations even for filamentous fungal cells, leading to the rapid development of IA high-yield mutant strains.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권1호
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• pp.43-47
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• 2006

Ginseng (Panax ginseng CA. Meyer) hairy root cultures, which are established via the infection of ginseng root discs with Rhizobium rhizogenes, have been used to construct profiles of both biomass growth and nutrient consumption in flask cultures. In a 250 mL shake flask culture, the maximum biomass was observed on the 59th day of the culture period, at 216.8 g (fresh wt) per liter or 11.4 g (dry wt) per liter. The hairy roots were determined to have a growth rate of 0.355 g-DW/g cells/day during the exponential growth phase and a maximum specific growth rate on day 7. Total ginseng saponin and phenolic compound contents were noted to have increased within the latter portion of the culture period. Linear correlations between increases in biomass weight and nutrient uptake were used to imply the conductivity yield $2.60g-DW/(L{\cdot}mS)$ and carbon yield 0.45 g-DW/(g sugar) in the 250 mL flask cultures. The biomass yield when two different nitrogen sources were used (ammonia and nitrate) was shown to remain approximately constant. at $0.47g-DW/(L{\cdot}mM\;NH_4$) and $0.33g-DW/(L{\cdot}mM\;NO_3$); it remained at these levels for 16 days with the ammonia. and for 24 days with the nitrate. The biomass yield when a phosphate source was used was also shown to remain approximately constant for 9 days, at $3.17g-DW/(L{\cdot}mM\;PO_4$), with an $R^2$ of 0.99.

• 한국염색가공학회지
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• 제6권4호
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• pp.1-8
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• 1994

To improve the antimicrobial activity and crease resistance of Korean traditional Hansan ramie fabrics, partially saponified polyethylene(PPS) was used as a softening water repellent agent and 3-(trimethoxysilyl)propyl dimethyl octadecyl ammonium chloride(QAC) as a antimicrobial agent. The antimicrobial activity was effective by treatments of PPS, QAC and PPS/QAC for shake flask test. For the halo test, PPS/QAC showed good antimicrobial activity. It was found that the desirable composition of H$_{2}$O/PPS/QAC is 98/1/1 for improving the antimicrobial activity and crease resistance of the fabrics.

• 한국염색가공학회지
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• 제5권1호
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• pp.33-39
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• 1993

This study was to examine the anti-bacteria effect of chrome-tanned garment leathers by various processes to article from hide. Anti-bacterial test by halo test and shake flask method, and pH value measurment are carried out in this study. The results can be obtained as follows: 1. In the soaking process of chrome-tanned garment leathers, it needs more effective anti-bacterial treatment. 2. pH value of samples by various processes has affected to anti-bacteria effect. 3. Chrome used by the tanning and the neutralization process have been found to be the anti-bacteria activity. 4. The dyeing, the fatliquoring and the finishing process has required anti bacteria treatment.

• Journal of Microbiology and Biotechnology
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• 제4권1호
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• pp.56-62
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• 1994

A yeast strain, BT001, which can directly ferment D-xylose to ethanol was isolated from forest soils, and then identified as Candida sp. Cultural conditions for the optimum ethanol production, along with the effects of aeration on cell growth and ethanol production were investigated. Aeration stimulated the cell growth and the volumetric rate of ethanol production, but decreased the ethanol yield. Optimum temperature and initial pH for the ethanol production were $33{\circ}^C$ and 6.0, respectively. In a shake flask culture, this strain produced 52.3 g ethanol per liter from 12%(w/v) D-xylose after incubation for 96 hours. Ethanol yield was 0.436 g per g D-xylose consumed. This corresponds to 85.8% of theoretical yield. Also, this yeast strain produced ethanol from D-galactose, D-glucose and D-mannose, but not from L-arabinose and L-rhamnose. Among these sugars, D-glucose was the fastest in being converted to ethanol sugars.

• Journal of Microbiology and Biotechnology
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• 제16권8호
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• pp.1185-1191
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• 2006

The expression of a pullulanase gene in Pichia pastoris was investigated. The gene encoding pullulanase was cloned by PCR using the chromosomal DNA of Bacillus naganoensis as the template. The expression vector pPIC9K-Pu was constructed by inserting the pullulanase gene into plasmid pPIC9K and then transformed into Pichia pastoris SMD 1168 by electroporation. Activity determination, SDS-PAGE, and PCR amplification indicated that the gene of the pullulanase from B. naganoensis had successfully been expressed in SMD 1168 and the molecular size of the expressed recombinant product was about 119.9 kDa. This is the first report on the successful expression of the pullulanase from B. naganoensis in P. pastoris. The transformant secreted recombinant pullulanase with the activity of 350.8 IU/ml in shake-flask culture. The properties of the recombinant pullulanase were characterized.