• Journal of Microbiology and Biotechnology
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• 제23권4호
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• pp.489-498
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• 2013

A new Bacillus strain degrading starch, named Bacillus sp. UEB-S, was isolated from a southern Tunisian area. Amylase production using solid-state fermentation on millet, an inexpensive and available agro-resource, was investigated. Response surface methodology was applied to establish the relationship between enzyme production and four variables: inoculum size, moisture-to-millet ratio, temperature, and fermentation duration. The maximum enzyme activity recovered was 680 U/g of dry substrate when using $1.38{\times}10^9$ CFU/g as inoculation level, 5.6:1 (ml/g) as moisture ratio (86%), for 4 days of cultivation at $37^{\circ}C$, which was in perfect agreement with the predicted model value. Amylase was purified by Q-Sepharose anion-exchange and Sephacryl S-200 gel filtration chromatography with a 14-fold increase in specific activity. Its molecular mass was estimated at 130 kDa. The enzyme showed maximal activity at pH 5 and $70^{\circ}C$, and efficiently hydrolyzed starch to yield glucose and maltose as end products. The enzyme proved its efficiency for digesting raw cereal below gelatinization temperature and, hence, its potentiality to be used in industrial processes.

• KSBB Journal
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• 제21권4호
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• pp.286-291
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• 2006

본 연구에서는 적효모 X. dendrorhous KCTC 7704로부터 여러 ${\beta}$-ionone 내성 변이균주를 선별하였다. 야생균 KCTC 7704는 ${\beta}$-ionone 0.021 mM 농도에서 생육이 현저히 저하되었지만, NTG처리 후 ${\beta}$-ionone 0.1 mM 농도에서 선별된 변이균주는 ${\beta}$-ionone 0.15 mM에서도 70% 이상의 상대 생육율을 나타내는 매우 강한 ${\beta}$-ionone 내성을 갖고 있었다. 여러 ${\beta}$-ionone 농도에서 선별한 변이균주들을 $20^{\circ}C$에서 4일간 회분식 발효로 배양하여 그 특성을 조사하였다. 선별된 가장 우수한 변이균주는 야생균주보다 카로티노이드 생성능이 2.3배 향상(즉 $1.2{\mu}g$ of total carotenoids per mg of dry cells)되었으며 유기산과 같은 대사산물은 거의 생성하지 않았다. 여러 탄소원 들에 대한 비교 발효특성 연구 결과 과당이나 자당을 사용했을 때봐 비교하여 포도당 배지에서 최종 균체농도 및 총 카로티노이드 생성량이 많았다. 포도당이 제한되는 연속발효(dilution rate $0.04h^{-1}$) 실험을 통하여 pH의 영향을 조사한 결과 균체농도 및 총 카로티노이드 생성은 pH 4.0 조건하에서 최적인 것을 알 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제26권10호
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• pp.1781-1789
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• 2016

Glargine insulin is a long-acting insulin analog that helps blood glucose maintenance in patients with diabetes. We constructed the pPT-GI vector to express prepeptide glargine insulin when transformed into Escherichia coli JM109. The transformed E. coli cells were cultured by fed-batch fermentation. The final dry cell mass was 18 g/l. The prepeptide glargine insulin was 38.52% of the total protein. It was expressed as an inclusion body and then refolded to recover the biological activity. To convert the prepeptide into glargine insulin, citraconylation and trypsin cleavage were performed. Using citraconylation, the yield of enzymatic conversion for glargine insulin increased by 3.2-fold compared with that without citraconylation. After the enzyme reaction, active glargine insulin was purified by two types of chromatography (ion-exchange chromatography and reverse-phase chromatography). We obtained recombinant human glargine insulin at 98.11% purity and verified that it is equal to the standard of human glargine insulin, based on High-performance liquid chromatography analysis and Matrix-assisted laser desorption/ionization Time-of-Flight Mass Spectrometry. We thus established a production process for high-purity recombinant human glargine insulin and a method to block Arg (B31)-insulin formation. This established process for recombinant human glargine insulin may be a model process for the production of other human insulin analogs.

• 한국미생물·생명공학회지
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• 제16권2호
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• pp.105-110
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• 1988

전분이용성 세포융합 효모를 이용하여 단세포단백질 생산을 위한 기초실험을 행하였다. 전분배지에서 균체생성이 우수한 fusant12 균주의 배양조건은 최적질소원 (NH$_4$)$_2$SO$_4$ 0.1%, 최적 soluble starch 농도 7%, 최적 초기pH5.6이었다. Fusant12균체의 자기소화에 의한 가용성 단백질의 추출은 효모현탁액에 ethyl acetate를 5%(v/ v)되게 첨가하여 30min간 액화전처리과정을 행하므로 효과적으로 얻을 수 있었다. 전분이용성 효모인 fusant 12균주와 비전분이용성 효모인 Torulopsis candida의 혼합배양으로 균체생성량을 증가시킬 수 있었으며, 혼합배양시 종균접종혼합비는 6대4일 때 효과적이었다. Fusant 12균주 단독 및 Torulopsis candida와의 혼합배양시 tapioca 배지에서의 균체생성량은 soluble starch 배지에서 보다 약 2.5배 증가하였다. 건조균체의 조단백질함량은 39%, 핵산함량은 5.8%이고 균체단백질은 FAO 표준단백질과 비교하여 필수아미노산중 methionine 함량이 낮으며, Iysine 함량은 높았다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권4호
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• pp.267-273
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• 2004

The optimization of culture conditions for the bacterium Pseudomonas aeruginosa BYK-2 KCTC 18012P, was performed to increase its rhamnolipid production. The optimum level for carbon, nitrogen sources, temperature and pH, for rhamnolipid production in a flask, were identified as 25 g/L fish oil, 0.01% (w/v) urea, 25 and pH 7.0, respectively. Optimum conditions for batch culture, using a 7-L jar fermentor, were 200 rpm of agitation speed and a 2.0 L/min aeration rate. Under the optimum conditions, on fish oil for 216 h, the final cell and rhamnolipid concentrations were 5.3 g/L and 17.0 g/L respectively. Fed-batch fermentation, with different feeding conditions, was carried out in order to increase, cell growth and rhamnolipid production by the Pseudomonas aeruginosa, BYK-2 KCTC 18012P. When 2.5 g of fish oil and 100 mL basal salts medium, containing 0.01 % (w/v) urea, were fed intermittently during the fermentation, the final cell and rhamnolipid concentrations at 264 h, were 6.1 and 22.7 g/L respectively. The fed-batch culture resulted in a 1.2-fold increase in the dry cell mass and a 1.3-fold increase in rhamnolipid production, compared to the production of the batch culture. The rhamnolipid production-substrate conversion factor (0.75 g/g) was higher than that of the batch culture (0.68 g/g).

• 한국작물학회지
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• 제44권1호
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• pp.20-25
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• 1999

This experiment was conducted to elucidate the relation-ship between vertical distribution of rice roots and yield traits under field conditions. Eight IRRI's new plant type rices (NPTRs) were tested in a volcanic ash soil paddy field under dense (IO 10 cm) and common (20 20 cm) planting densities. These lines were evaluated to have more spikelet numbers per panicle (SNP), lower filled grain rate (FGR), and lower rough grain weight per hill (RGWH). In dense planting, rough grain weight per stem (RGWS) was increased due to heavier culm and leaf dry weight (CLDW), and both RGWS and CLDW were related with the percentage of root distribution (%RWI) in the 10~30 cm soil layer, while in common planting, RGWS was not closely related with CLDW. SNP was highly related with root dry weight (RDW) in the 0~10cm soil layer. FGR was mainly affected by ROW in the 10~30 cm soil layer under both planting densities. RGWS was positively correlated with top dry weight (TDW) and harvest index (HI), and TDW was positively correlated with RWI under common planting or %RWI under dense planting, and HI was positively correlated with RWI in the 10~30 cm soil layer only under dense planting. RGWS was closely related with root weight index by dry weight (RWI) in the 10~30 cm soil layer and %RWI in the 0~30 cm or 10~30 cm soil layer under dense planting, and with only RWI in the 10~30 cm soil layer under common planting. But RGWH showed the close positive relationship with RDW and RWI in the 10~30 cm soil layer under dense planting, while under common planting, it showed the close positive relationship with RWI and %RWI in the 10~30 cm soil layer or %RWI in the 0~30 cm soil layer. The deeper root system in rice, especially under dense planting, is important for high yield of NPTRs focusing on the increment of top mass production and harvest index.

• 한국식품조리과학회지
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• 제26권6호
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• pp.727-736
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• 2010

The purpose of this research was to compare the physicochemical compositions and morphological properties of five varieties of rice flours (RR, RGD, RSGD, RWDG, RWGD). RR was raw milled rice without washing, RGD was raw rice flour without soaking, RSGD was raw milled rice flour with 0 hr of soaking, RWDG was raw rice flour with 8 hr of soaking and grinding after drying, and RWGD was raw rice flour with 8hr of soaking and drying after grinding. The protein and lipid contents of wet milling rice flour (RSGD, RWDG, RWGD) were significantly lower than those of dry milling rice flour (RR, RGD). L and a values were significantly increased in wet milling rice flour, and b value was significantly increased in dry milling rice flour. Scanning electron microscopy (SEM) showed that RWDG and RWGD were distributed as separated fine particles in rice flours. The WBC of RWDG and RWGD were higher than those of other rice flours. Solubility was significantly increased according to the temperature, and swelling power of RWDG was higher than that of other rice flours at 50 and $60^{\circ}C$. Using RVA, the initial pasting temperature and setback of RWDG were lower and the peak viscosities of RSGD and RWDG were higher than those of other rice flours. Using a mixograph, peak times were not significantly different among the groups, wheras peak heights were significantly decreased in RSGD, RWDG, and RWGD. The peak width of RWGD was lower than those of other rice flours. Based on these findings, RWDG flour was less damaged, and had a lower setback and pasting temperature, which makes it an appropriate rice flour for commercial mass production.

• 한국작물학회지
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• 제49권2호
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• pp.73-81
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• 2004

Effects of ambient and elevated $\textrm{CO}_2$ and high temperature, and their interactions with zero and applied nitrogen supply (NN-no nitrogen and AN-applied nitrogen) were studied on soybean (Glycine max L.) in 2001. In this experiment, elevated $\textrm{CO}_2$ (650 $\mu\textrm{mol}.\textrm{mol}^{-1}$) and temperature (+$5^{\circ}$) increased total dry mass at final harvest by 125% and 119% and seed weight per plant by 57% and 105% for NN and AN plants, respectively. Although the influence of temperature and temperature x $\textrm{CO}_2$ were not significant, the influences of $\textrm{CO}_2$ concentration and temperature x $\textrm{CO}_2$ concentration were significant on total dry weight and seed weight, respectively. In particular, seed weight per plant was increased, while weight per one hundred seed weight was decreased with elevated $\textrm{CO}_2$ and temperature. The N supply increased biomass and seed weight per soybean plants. The results of this study suggest that the long-term adaptation of soybean growth at an elevated $\textrm{CO}_2$ concentration and high temperature might potentially result in a increase in dry matter production and yield.

• Mycobiology
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• 제35권3호
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• pp.135-144
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• 2007

The removal efficiency of the heavy metals Zn, Pb and Cd by the zoosporic fungal species Saprolegnia delica and the terrestrial fungus Trichoderma viride, isolated from polluted water drainages in the Delta of Nile in Egypt, as affected by various ranges of pH values and different temperature degrees, was extensively investigated. The maximum removal efficiency of S. delica for Zn(II) and Cd(II) was obtained at pH 8 and for Pb(II) was at pH 6 whilst the removal efficiency of T. viride was found to be optimum at pH 6 for the three applied heavy metals. Regardless the median lethal doses of the three heavy metals, Zn recorded the highest bioaccumulation potency by S. delica at all pH values except at pH 4, followed by Pb whereas Cd showed the lowest removal potency by the fungal species and vice versa in case of T. viride. The optimum bio-mass dry weight production by S. delica was found when the fungus was grown in the medium treated with the heavy metal Pb at pH 6, followed by Zn at pH 8 and Cd at pH 8. The optimum biomass dry weight yield by T. viride amended with Zn, Pb and Cd was obtained at pH 6 for the three heavy metals with the maximum value at Zn. The highest yield of biomass dry weight was found when T. viride treated with Cd at all different pH values followed by Pb whilst Zn output was the lowest and this result was reversed in case of S. delica. The maximum removal efficiency and the biomass dry weight production for the three tested heavy metals was obtained at the incubation temperature $20^{\circ}C$ in case of S. delica while it was $25^{\circ}C$ for T. viride. Incubation of T. viride at higher temperatures ($30^{\circ}C\;and\;35^{\circ}C$) enhanced the removal efficiency of Pb and Cd than low temperatures ($15^{\circ}C\;and\;20^{\circ}C$) and vice versa in case of Zn removal. At all tested incubation temperatures, the maximum yield of biomass dry weight was attained at Zn treatment by the two tested fungal species. The bioaccumulation potency of S. delica for Zn was higher than that for Pb at all temperature degrees of incubation and Cd bioaccumulation was the lowest whereas T. viride showed the highest removal efficiency for Pb followed by Cd and Zn was the minor of the heavy metals.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.190-193
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• 2002

The processing technology of organic thin-film transistors (Ons) performances have improved fur the last decade. Gate insulator layer has generally used inorganic layer, such as silicon oxide which has properties of a low electrical conductivity and a high breakdown field. However, inorganic insulating layers, which are formed at high temperature, may affect other layers termed on a substrate through preceding processes. On the other hand, organic insulating layers, which are formed at low temperature, dose not affect pre-process. Known wet-processing methods for fabricating organic insulating layers include a spin coating, dipping and Langmuir-Blodgett film processes. In this paper, we propose the new dry-processing method of organic gate dielectric film in field-effect transistors. Vapor deposition polymerization (VDP) that is mainly used to the conducting polymers is introduced to form the gate dielectric. This method is appropriate to mass production in various end-user applications, for example, flat panel displays, because it has the advantages of shadow mask patterning and in-situ dry process with flexible low-cost large area displays. Also we fabricated four by four active pixels with all-organic thin-film transistors and phosphorescent organic light emitting devices.