• 한국미생물·생명공학회지
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• 제15권2호
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• pp.112-115
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• 1987

B. megaterium ATCC 13639와 E. aerogenges의 비타민 B$_{12}$ 생산을 위한 최적 pH는 각각 6.0과 5.0으로 pH의 영향을 크게 받았으나 두 세균에 의한 riboflavin 생산은 pH에 따른 변화가 거의 없었다. Sucrose를 첨가하면 두 비타민 생산량이 크게 증가되었고 최적pH도 변함을 알 순 있었다. 두 세균에 의한 두 비타민 생산에 미치는 온도의 영향은 pH에 비하여 아주 적었다. 이상의 결론은 장차 여러 가지 식품 폐기물을 이용한 비타민 B$_{12}$와 riboflavin의 생산이 가능함을 보여주었다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.525-528
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• 2001

본 연구는 메탄을 최대로 발생시킬 수 있는 최적조건을 탐색하는데 있다. 메탄을 많이 발생 시킬 수 있는 최적 온도와 pH를 결정한 다음, 여러 가지 탄소원에 대해 조사하였다. 온또는 $25^{\circ}C$. $30^{\circ}C$. $55^{\circ}C$에서, pH 는 pH 2, 4, 6, 8. 10 에서 , 그리고 탄소원은 methanol. formic acid. sodium acetate. succinic acid, glucose 에서 조사하였다. 결과적으로 볼 띠 1. 온도는 $55^{\circ}C$. pH 는 중성부근. 탄소원은 methanol 인 조건에서 가장 많은 메탄을 얻을 수 있었다.

• 한국식품영양과학회지
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• 제26권4호
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• pp.620-624
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• 1997

온도, pH, 배양시간을 세가지 인자로 하고 반응표면 분석을 통하여 Bacillus subtilis DC-2균에 의한 색소 생성 및 DPPH($\alpha$,$\alpha$-diphenyl-$\beta$-picryl-hydrazyl)에 의한 전자공여성의 최적 조건을 조사하였다. 색소생성능에는 배양온도가 10% 유의수준에서 영향을 미치는 것으로 나타났으며, DPPH에 의한 전자공여성의 경우 배양온도가 5% 유의수준, pH가 10% 유의수준에서 영향을 미치며, 배양시간은 10% 유의수준에서 영향을 미치지 않는 것으로 나타났다. Bacillus subtilis DC-2의 색소생성 최적 조건은 배양온도 39.$25^{\circ}C$, pH 8.83 및 84.41 시간으로 나타났으며 DPPH에 의한 전자공여성은 배양 온도 39.19$^{\circ}C$, pH 8.84 및 82.21시간에서 가장 높은 것으로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제16권12호
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• pp.1856-1861
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• 2006

A Bacillus sp. A-6 strain that produced xylanase was isolated from rice bran. The optimal temperature and pH for xylanase activity of the culture supernatant of Bacillus sp. A-6 were 40$^{\circ}C$ and pH 7, respectively. The optimal temperature and pH for xylanase production in the xylan medium were 30$^{\circ}C$ and pH 9, respectively. The optimal concentrations of oat spelt xylan and peptone for xylanase production were 0.5% and 1.5%, respectively. The best nitrogen sources for xylanase production was beef extract, but xylanase production was also supported comparably by tryptone and peptone. The bacterial growth in the optimal xylan medium reached stationary growth phase after 12 h of incubation. The xylanase production in the culture supernatant increased dramatically during the initial 12 h exponential growth phase and then remained constant at 23.8-24.5 unit/ml during the stationary growth phase. The pH of the culture medium decreased from 8.8 to 6.7 during the exponential growth phase and subsequently increased to 8.1 during the stationary growth phase. Rice bran, sorghum bran, and wheat bran as well as oat spelt xylan induced xylanase production. The xylanase production was repressed when glucose was added to the xylan-containing medium.

• 한국미생물·생명공학회지
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• 제23권3호
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• pp.304-310
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• 1995

A thermophilic bacterium producing the extracellular cellulase-free xylanase was isolated from soil and has been identified as Bacillus sp. The optimal growth temperature was 50$\circ$C and the optimal pH, 7.0. Under the optimal growth condition, maximal xylanase production was 2.2 units/ml in the flask culture. The enzyme production was induced by xylan and xylose, but was repressed by sucrose or trehalose. The partially purified xylanase was most active at 70$\circ$C. It was found that the enzyme was stable at 65$\circ$C for 10 hours with over 75% of the activity. The enzyme was most active at pH 7.0 and retained 90% of its maximum activity between pH 5.0 and pH 9.0 though Bacillus sp. was not grown on alkaline conditions (>pH 8.0). In addition, the activity of xylanase was over 60% at pH 10.0. At the ambient temperature, the enzyme was stable over a pH range of 5.0 to 9.0 for 10 h, indicating that the enzyme is thermostable and alkalotolerant. The activity of xylanase was completely inhibited by metal ions including Hg$^{2+}$ and Fe$^{2+}$, while EDTA, phenylmethylsulfonyl fluoride (PMSF), $\beta$-mercaptoethanol and SDS didn't affect its activity. The enzyme was also identified to exert no activity on carboxymethylcellulose, laminarin, galactomannan, and soluble starch.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권4호
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• pp.297-302
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• 2004

A chitinase-producing bacterium was isolated from seashore mud around Beobseongpo in Chunmam province through the use of a selective enrichment culture. The best chitinase producing strain was isolated and identified as Serratia marcescens KY from its characteristics. For effective production of chitinase, optimum pH, temperature, and agitation speed were investigated in flask cultures. The optimum pH using Serratia marcescens KY was between pH 6 and 7 and the chitinase produced was 37.9 unit/mL. On the other hand, the optimal pH of the Serratia marcescens ATCC 27117 was 7.5, and the produced amount of chitinase was 35.2 unit/mL. The optimal temperature for chitinase production for Serratia marcescens KY and Serratia marcescens ATCC 27117 was $30^{\circ}$. The cell growth pattern at different temperature was almost identical to the chitinase production. To investigate the optimal shaking speed under optimal culture, speeds were varied in the range of 0∼300 rpm. The maximum production of chitinase was carried at 200 rpm although the cell growth was the highest at 150 rpm. It indicates that oxygen adjustment is required for the maximum chitinase production. Using optimal conditions, batch cultures for comparing Serratia marcescens KY and Serratia marcescens ATCC 27117 were carried out in a 5 L fermentor. The oxygen consumption was increased with the increase of culture. Especially, at 120 h of culture Serratia marcescens KY and Serratia marcescens ATCC 27117 produced 38.3 unit/mL, and 33.5 unit/mL, respectively.

• 상하수도학회지
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• 제28권5호
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• pp.601-608
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• 2014

A coagulation-flocculation (CF) process using aluminum sulfate as a coagulant was employed to treat highly suspended solids in tunnel wastewater. Response surface methodology (RSM) based on a Box-Behnken design was applied to evaluate the effects of three factors (coagulant dosage, pH and temperature) on total suspended solids (TSS) removal efficiency as well as to identify optimal values of those factors to maximize removal of TSS. Optimal conditions of coagulant dosage and pH for maximum TSS removal changed depending on the temperature ($4{\sim}24^{\circ}C$). As temperature increased, the amount of coagulant dosage and pH level decreased for maximum TSS removal efficiency during the CF process. Proper adjustment of optimal pH and coagulant dosage to accommodate temperature fluctuations can improve TSS removal performance of the CF process.

• 생명과학회지
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• 제13권4호
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• pp.498-504
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• 2003

맛버섯( Pholiota nameko KACC50453)의 균사체 배양 특성에 관한 연구 결과 맛버섯 균사체의 배양에 적합한 기본 배지는 ME였으며, 최적 배양 온도는 $25^{\circ}C$, 최적 초기 pH는 5.5였다. 맛버섯 균사체 생장을 위한 최적 배지 조성은 glucose 3%(w/v),malt extrac 0.25%(w/v), yeast extract 0.25%(w/v),$KH_2PO_4$ 0.046%(w/v),$K_2HPO_4$ 0.1%(w/v),$MgSO_4$ $.$$7H_2O$0.05% (w/v)로 나타났다.기본배지(ME)와 최적배지로 액체 배양한 결과 최적 배지에서 균사생장이 양호하였다.

• 한국표면공학회지
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• 제25권4호
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• pp.189-206
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• 1992

The effect of activation and electroless nickel plating conditions on contact properties was investi-gated for selective electroless nickel plating of Si wafers in order to obtain an optimum condition of con-tact hole filling. According to RCA prosess, p-type silicon (100) surface was cleaned out and activated. The effects of temperature, DMAB concentration, time, and strirring were investigated for activation of p-type Si(100) surface. The optimal activation condition was 0.2M HF, 1mM PdCl2, 2mM EDTA,$ 70^{\circ}C$, and 90sec under ultrasonic vibration. In electroless nickel plating, the effect of temperature, DMAB concentra-tion, pH, and plating time were studied. The optimal plating condition found was 0.10M NiSO4.H2O, 0.11M Citrate, pH 6.8, $60^{\circ}C$, 30minutes. The contact resistance of films was comparatively low. It took 30minutes to obtain 1$\mu\textrm{m}$ thick film with 8mM DMAB concentration. The film surface roughness was improved with decreasing temperature and decreasing pH of the plating solution. The best quality of the film was obtained at the condition of temperature $60^{\circ}C$ and pH 6.0. The micro-vickers hardness of film was about 800Hv. Plating rate of nickel on the hole pattern was slower than that of nickel on the line pattern.

• 생명과학회지
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• 제6권2호
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• pp.79-86
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• 1996

A bacterium producing pullulanase was from soil, and was identified Bacillus cereus and named as Bacillus cereus JK36. The optimal culture conditions for the efficident production of pullulanase from B. cereus JK36 was obtained by cultivating with the medium composed of 1% pullulan, 1% teast extract, 1% bactopeptone, 0.1% NaH$_{2}$PO$_{4}$, 2H$_{2}$O, 0.02% MgSO$_{4}$\ulcorner7H$_{2}$O at 40$\circ$C, initial pH 6.5 for 70 hours. Using the culture supernatant as crude enzyme, the optimal pH and temperature of the pullulanase of this strain were 6.5 and 50$\circ$C. In effect of pH and temperature on the stability of the enzyme, the enzyme was stable in the range of pH6.0$\sim$9.5 and up to 40$\circ$C, respectively. The hydrolysis product on pullulan was mainly maltotriose.