• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1978.10a
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• pp.205.3-205
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• 1978

Methanol이용 미생물의 집적배양을 통해 토양 및 하수로부터 분리하여 그 중에서 비교적 생육속도가 빠른 균주를 선별하였다. 이 균주는 형태적, 생리적 특성에 따라 Methylomonas methanolica로 동정되었으며 obligate methylotroph 이었다. 균체 생산량을 높이기 위한 배지조성과 배양 최적조건을 검토한 결과, 탄소원으로는 methanol 0.8%(v/v), 질소원은 $(NH_4)_2SO_4$ 0.6%, 금속이온은 $MgSO_4.$ $7H_2O$ 0.1%이었고, 최적 pH는 6.3, 최적 배양온도는 $32.5^{\circ}C이었으며,$ 생육인자는 요구되지 않았다. 그리고 최적 배양조건에서 1ι용 fer-mentor를 사용하여 회분배양을 하였을 때 최대 비증식속도 0.19$hr^{-1}$, 균체수율은 0.47g dry cell/g-methanol이었다. Chemostat를 이용한 연속배양시 균체생산을 위한 최적희석률은 D=0.1 $hr^{-1}$이었고 이때의 균체생산속도는 0.21g- dry cell/hr이었다. 생산된 건조균체의 단백질과 핵산함량은 각각 73%, 12% 이었다.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2004.11a
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• pp.161-162
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• 2004

주암호와 상사호의 담수와편모조 P. bipes 휴면포자의 환경조건에 따른 발아특성을 밝하기 위하여, 매월 채집된 휴면포자를 다양한 수온, 광조건, 영양염, pH 등에서 발아실험을 실시하였다. 실험결과, P. bipes 휴면포자는 수온 $20^{\circ}C$, 광도 $20{\mu}E/m^2/s$, 풍부한 영양원, pH 6-8 등이 최적발아조건으로 밝혀졌다. 특히, 환경요인 중 수온과 광조건은 휴면포자의 발아에 상대적으로 좀더 큰 영향을 주는 것으로 판단된다.

• The Korean Journal of Mycology
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• v.31 no.1
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• pp.14-21
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• 2003

This study was carried out to obtain the basic data on artificial culture of Lampteromyces japonicus. Favorable media for mycerial growth were glucose peptone medium, malt yeast extract, yeast malt peptone, potato dextrose medium. The optimum conditions for the mycelial growth were $30^{\circ}C$ and pH 6.0. Dextrose as a carbon source was favorable to mycelial growth. The optimal dextrose concentration was 1.2%. As nitrogen sources, yeast extract, $(NH_4)_2HPO_4$ and 0.2% for glutamine. The mineral salts of $Al_2(SO_4)_3{\cdot}14H_2O$ were effective and the optimal concentration was 0.1 M.

• Korean Journal of Food Science and Technology
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• v.53 no.2
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• pp.195-203
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• 2021

Aureobasidium pullulans, a black yeast, produces pullulan, a linear α-glucan composed of maltotriose repeating units linked by α(1→6)-glycosidic linkages. Pullulan can be widely used in food, cosmetic, and biotechnology industries. In this study, we isolated eight strains of A. pullulans from Forsythia koreana, Magnolia kobus DC., Spiraea prunifolia var. simpliciflora, Cornus officinalis, Cerasus, and Hippophae rhamnoides. Among them, A. pullulans MR was selected as the best pullulan producer. The effects of a carbon source, a nitrogen source, and pH on pullulan production were examined. The optimal cultivation conditions for pullulan production by A. pullulans MR were determined by response surface methodology as 15% sucrose, 0.4% soy peptone, and an initial pH of 7 at 26℃. Under these conditions, the predicted pullulan production was 47.6 g/L, which was very close to the experimental data (48.9 g/L).

• Microbiology and Biotechnology Letters
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• v.30 no.2
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• pp.142-150
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• 2002

Streptomyces polychromogenes IFO 13072 was used as a strain producing cholesterol oxidase(EC 1.1.3.6). The conditions of cholesterol oxidase production were investigated. The optimum composition of medium for production of the enzyme was 1% dextrin, 0.5% casamino acid, 0.1% $KH_2$PO$_4$, 0.5% $NaNO_3$ and 0.05% $MgSO_4$(pH 7.3). The enzyme was purified specifically by cholesterol affinity column chromatography with a yield of 23.2%. The purified enzyme showed a single polypeptide on SDS-PAGE and the molecular weight was estimated about 52,000 daltons. The optimum pH and temperature of the cholesterol oxidase were pH 7.0 and $37^{\circ}C$, respectively. The enzyme was stable in the range of pH 6.0~7.0 and $25^{\circ}C$. The cholesterol oxidase activity was strongly inhibited by metal ions such as $Hg^{2＋}$ and $Fe^{2＋}$ and inhibitors such as dithiothreitol, mercaptoethanol and isonicotinic acid. The Michaelis constant(Km) for the cholesterol was found to be 25 mM by Lineweaver-Burk plot analysis.

• Microbiology and Biotechnology Letters
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• v.15 no.6
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• pp.441-445
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• 1987

The gene coding for alkaline amylase of alkalophilic Bacillus sp. AL-8 was cloned and expressed in Escherichia coli which was lack of amylase activity. For the cloning of the alkaline amylase gene, the chromosomal DNA and plasmid vector pBR322 were cleaved at the site of EcoRI and the gene was cloned. The selection of the transformants carrying the amylase gene was based on the their antibiotics resistance and amylase activity of the transformants. The recombinant plasmids pJW8 and pJW200 containing 5.8Kb and 3.0Kb EcoRI inserts respectively were proved to can the alkaline amylase gene. Alkaline amylase expressed in E. coli was characterized. The enzyme was proved to be stable at the range of alkaline pH.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2008.11a
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• pp.233-236
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• 2008

Ru:Sn:Sb 전극의 성능에 영향을 미치는 인자에 대하여 조사하여 다음의 결과를 얻었다. 0.5-3 A로 전류를 변화시켰을 때 최적 전류는 2 A로 나타났다. 실험에 사용한 전해질의 RhB 분해 성능은 NaCl > KCl > HCl > Na$_2$SO$_4$로 나타났다. 최적 NaCl 농도는 1.75 g/L로 나타났다. 최적 공기 공급량은 2 L/min으로 최적 pH는 3으로 나타났다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.6
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• pp.888-895
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• 2015

For effective utilization of butter clam shell as a natural calcium resource, the optimal conditions for preparation of calcium acetate (BCCA) with high solubility were determined using response surface methodology (RSM). The polynomial models developed by RSM for pH, solubility, and yield were highly effective in describing the relationships between factors (P<0.05). Increased molar ratio of calcined powder (BCCP) from butter clam shell led to reduction of solubility, yield, color values, and overall quality. Critical values of multiple response optimization to independent variables were 2.70 M and 1.05 M for acetic acid and BCCP, respectively. The actual values (pH 7.04, 93.0% for solubility and 267.5% for yield) under optimization conditions were similar to predicted values. White indices of BCCAs were in the range of 89.7~93.3. Therefore, color value was improved by calcination and organic acid treatment. Buffering capacity of BCCAs was strong at pH 4.88 to 4.92 upon addition of ~2 mL of 1 N HCl. Calcium content and solubility of BCCAs were 20.7~22.8 g/100 g and 97.2~99.6%, respectively. The patterns of fourier transform infrared spectrometer and X-ray diffractometer analyses from BCCA were identified as calcium acetate monohydrate, and microstructure by field emission scanning electron microscope showed an irregular form.

• Journal of Life Science
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• v.6 no.2
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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.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.6
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• pp.745-753
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• 2007

By struvite and hydroxyapatite crystallization, was high concentration of nitrogen and phosphorus in wastewater simultaneously. Particularly, removal of nitrogen and phosphate for crystallization have been applied to landfill leachates and animal wastewater. The purpose of this study is to decide the optimum struvite crystallization factors, sequence of $Mg^{2+}$ addition, pH control and the molar ratio of $Mg^{2+}$ over $PO_4^{3-}$. In conclusion, dosage of the magnesium followed by pH control formed magnesium hydroxide, so pH was decreased. Therefore, pH adjustment should followed by after magnesium dosage and then pH should be adjusted to 11. Over pH 10, it was not good for struvite crystallization efficiency by side reaction. Following of the $Mg^{2+}$ and the $PO_4^{3-}$ are dosed excessively, the removal efficiency of the $NH_4^+$ increased. A molar ratio of $Mg^{2+}:NH_4^+:PO_4^{3-}$, 1.3:1:1.3 was the most on effective for $NH_4^+$ removal at pH 9.5. But for the perfect removal $NH_4^+$, it is thought to be that molar ratio should be 2:1:2.