• Journal of Applied Biological Chemistry
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• 제54권3호
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• pp.153-158
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• 2011

본 연구에서는 Bacillus subtilis JK-1의 생물계면활성제 생산을 위한 배양 특성을 조사하기 위하여 다양한 배양 온도와 배지의 pH, NaCl 농도에 따른 균주의 생장과 배양액의 pH, crude 생물계면활성제의 표면장력을 배양 시간대별로 측정하였다. B. subtilis JK-1은 $15-45^{\circ}C$와 pH 6-10, 0-10% (w/v) NaCl 농도의 환경에서 생장과 생물계면활성제 생산이 가능하였으며, 배양액의 pH는 중성 또는 약알칼리성으로 점차 변화 하였다. 생물계면활성제 생산은 pH 7.0의 초기 배지에서 $35^{\circ}C$, 48시간 동안 배양했을 때 최대였으며, 이 때의 표면장력은 24.0mN/m이었다. 그리고 배지 내 NaCl 농도가 0% (w/v)에서 10% (w/v)로 증가할수록 균주 생육도는 감소하였고, 최종 배양액의 pH는 약알칼리성에서 산성으로 변화하였으며, 표면장력 값은 증가하였다.

• Korean Chemical Engineering Research
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• 제57권2호
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• pp.232-238
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• 2019

산업폐수 속의 대표적인 색도유발물질인 염료를 효과적으로 제거하기 위한 생체흡착제로 폴리에틸렌이민을 키틴에 가교결합한 PEI-chitin을 개발하였다. 대표적인 반응성염료인 Reactive Orange 16 (RO16)을 모델염료로 사용하였고, RO16에 대한 PEI-chitin의 흡/탈착 능력을 평가하기 위해 pH의 영향, 등온흡착, 흡착속도론, 탈착 실험을 수행하였다. 그 결과, Langmuir 식에 의해 산출된 최대흡착량은 pH 2에서 266.3 mg/g이었고, 흡착평형에 도달하는 시간은 50 mg/L에서는 약 20분, 100 mg/L에서는 약 60분 그리고 200 mg/L에서는 약 240분으로 평가되었다. 탈착실험은 암모니아/에탄올 혼합용액, NaOH, $NaHCO_3$, $Na_2CO_3$를 용리액으로 이용하여 평가하였으며, 암모니아/에탄올 혼합용액에서 75.24%로 가장 높은 탈착율을 보였다.

• 한국작물학회지
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• 제48권1호
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• pp.20-24
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• 2003

Proline is known as an osmotrotectant to enhance tolerance against both salt and dehydration stresses. A P5CS ($\Delta^1$-pyrroline-5-carboxylate synthetase) plays a major role in regulation of synthesis of proline. An overexpression of the mothbean P5CS gene in transgenic tobacco plant increased the levels of proline and osmotolerance. In an attempt to look for the possibility to use content of proline as well as a level of P5CS gene expression as molecular markers for salt tolerance, the amounts of proline and transcript levels of P5CS were measured as functions of either concentration of NaCl or length of treatment period among different species of zoysiagrass. Hybridzoysia showed the highest level of proline ($329\mu\textrm{g}$/g.f.w.) among five different species of zoysiagrass at 250 mM NaCl in 24 hours. The level of P5CS transcript was also the highest in the hybridzoysia at 250 mM NaCl in 24 hours. The transcriptions of P5CS gene were induced at the rates of 1.2, 1.2, 1.8, and 1.8, upon treatment of 250 mM NaCl in Z. japonica, Z. matrella, Z. sinica and hybridzoysia respectively. Based on a correlation between the level of P5CS transcript and the proline content among different species of zoysiagrass, a comparative structural analysis of the gene for P5CS from either Z. sinica or hybridzoysia may lead to an understanding of mechanism for salt tolerance shown differently among zoysiagrasses.

• 한국미생물·생명공학회지
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• 제24권6호
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• pp.664-670
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• 1996

The aim of the present research program was to develop a strain of actinomycetes producing antifungal substance. Soil samples were collected from various sites in Korea and a number of actinomycetes were isolated from the soil samples by applying selective agar for actinomycetes. Among over 440 isolates, a strain (NA-4803) producing antifungal substance against Trichophyton spp. Nannizzia otae and Pyricularia oryzae was selected. The strain NA-4803 was identified as strain similar to Streptoverticillium blastmyceticum with respect to morphological and physiological characteristics, lecithinase and lipolytic activity, degradation of organic compounds, resistance to antibiotics and utilization of carbon and nitrogen sources. But it showed some differences such as positive reaction of nitrate reduction, negative reaction of L-tyrosine degradation, resistance to cephaloridine, and utilization of I -rhamnose and inulin. The strain NA-4803 was named as Streptoverticillium sp. NA-4803.

• Journal of the Korean Wood Science and Technology
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• 제22권1호
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• pp.34-39
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• 1994

Effects of Mg-base acid sulfite and Mg- or Na-base bisulfite on pine bark cooking were examined. In the presence of 75 % free acid at 145 $^{\circ}C$, the rate of cooking and delignification was improved with the increase of total acid. However, the delignification could not be achieved by 50 % or more under these cooking conditions. When cooked with 50~65 % free acid and at 155~165 $^{\circ}C$, the rate of cooking and delignification was remarkably improved. Thus, the bark was delignified up to 73 % when cooked for 2 hours in the presence of 50 % free acid and 24 % total acid. Na-base bisulfite was slightly more effective than Mg-base bisulfite for cooking, giving 76 % delignification of pine bark. However, there was no significant difference in selectivity of delignification between Na- and Mg-base bisulfite cooking.

• 한국물환경학회지
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• 제24권6호
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• pp.670-675
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• 2008

Batch type adsorption and desorption tests were performed with different types (Powder, Granule) of Layered double hydroxides (LDHs) saturated with phosphate. The adsorption isotherm was approximated as a modified Langmuir type equation. The maximum adsorption capacity was 55 mg-P/g-LDH for powder type LDH, and 46 mg-P/g-LDH for granule type LDH. The highest phosphate desorption (79.6%) was obtained with 20% NaOH solution, whereas the desorption degrees were 4.8, 22.2% and 46.7% in the solutions of acidic condition (pH 4), 30% NaCl, and 3% NaOH, respectively. It was suggested that the optimal condition for the phosphate desorption from LDH was 30% NaCl + 3~6% NaOH solutions. The desorption characteristics of LDH was little influenced by adsorbent type.

• Journal of the Korean Wood Science and Technology
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• 제24권3호
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• pp.72-79
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• 1996

Cellulose I에서 Cellulose II로의 결정변태기구를 X선 및 전자선 회절법과 현미경적 방법을 이용하여 구명하였다. X선 회절 결과, Na-cellulose I을 고온에서 수세할 경우 Cellulose I과 Cellulose II의 혼합형 회절도가, 저온에서 수세할 경우 Na-cellulose IV의 회절도가 얻어졌다. 전자선회절 결과, 고온수세의 시료는 Cellulose I과 Cellulose II의 혼합형이 저온수세의 시료는 Cellulose II의 회절도가 얻어졌다. 또한 고온수세 시료의 전자선회절도로부터 섬유벽의 내측부가 외측부보다 재생 Cellulose I의 양이 많은 것이 확인되었다. 따라서 알칼리 팽윤시 섬유벽내에는 불완전한 팽윤이 발생하는데 그 정도는 내측부가 더욱 심한 것으로 생각된다. 이때 형성되는 불완전한 Na-cellulose I 은 고온 수세의 경우는 탈수에 의해 Cellulose I로, 저온수세의 경우는 수화에 의해 Cellulose II로 변태되지만 완전히 팽윤된 Na-cellulose I은 Cellulose I로 재생될 수 없는 것으로 생각된다. 현미경적 실험결과, mercerization과정에서 cellulose 분자쇄의 packing이나 conformation의 변화와 관련하여 microfibril 의 흐트러짐은 발생하지 않는 것으로 생각되었다.

• 식품과학과 산업
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• 제49권2호
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• pp.18-24
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• 2016

Sodium chloride (NaCl) is a very important as one of major food ingredients in food industries. Recently, as the potential risk of adult diseases such as hypertension by overingestion of sodium, health authorities of many countries are executing policies for the reduction of sodium to suppress the overingestion of sodium by intake of NaCl. As general ways, the replacement of NaCl with either alternative salts, such as solar salts and minerals, for examples calcium, magnesium, potassium, lactic acid, and so on, and the addition of flavor enhancers were used to reduce the contents of sodium in foods. Recently, controls of particle size of sodium chloride or release point are emerging as new salt-manufacturing technologies for the sodium reduction. Upon reducing NaCl in foods it is important to develop practically adaptable technologies on the basis of the consideration of the unique functions of NaCl in foods, in particular effects on rheological characters, function as a humectant, shorten shelf life time, and so on.

• 한국양식학회지
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• 제15권1호
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• pp.69-75
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• 2002

사육수의 저염분에 따른 급성 스트레스 반응 (코티졸, 글루코스, Na$^{+}$, K$^{+}$, Cl￣, 총단백질, ALT, AST, 헤마토크리트, 적혈구수, 헤모글로빈 농도, MCV, MCH 및 MCHC) 조사하였다. 예비사육 수조에서 사육하던 어류를 해수(35$\textperthousand$)가 공급되는 실험수조에서 30분이내에 담수 (0 $\textperthousand$)를 흘려주면서 l5 $\textperthousand$구와 0 $\textperthousand$구로 사육수를 교환하였다. 실험개시시 코티졸 농도는 1.6${\pm}$0.2 ng/$m\ell$로부터 15 $\textperthousand$구는 1시간째 3.5${\pm}$1.8 ng/$m\ell$, 3시간째와 24시간째에는 각각 1.7${\pm}$0.2 ng/$m\ell$와 3.0${\pm}$2.4 ng/$m\ell$로 유의한 차이를 보이지 않았다. 그러나 0 $\textperthousand$구는 1시간째 22.8${\pm}$3.8 ng/$m\ell$, 3시간째 9.3${\pm}$1.8 ng/$m\ell$, 24시간째 9.5${\pm}$0.2 ng/$m\ell$로 높아진 값을 보였다. 글루코스 함량은 실험개시시 17.7${\pm}$0.6 mg/dl로부터 15$\textperthousand$구와 0$\textperthousand$구는 1시간째 각각 96.2${\pm}$1.6 mg/dl, 155.8${\pm}$16.0 mg/dl로 높아졌다. 그러나 24시간째에는 각각 13.0${\pm}$3.2 mg/dl, 15.2${\pm}$1.4 mg/dl로 실험개시시 값으로 회복되었다. Na$^{+}$과 K$^{+}$은 15 $\textperthousand$구에서 차이를 보이지 않았으나, 0 $\textperthousand$구에서는 감소하는 경향을 보였다. 생존율은 48시간째부터 폐사하기 시작하여 144시간째에는 전량폐사하였다. 삼투압 조절 능력을 위한 여러가지 파라메타에서 15 $\textperthousand$구는 이상이 없는 것으로 추측되나, 0 $\textperthousand$구에서는 코티졸, Na$^{+}$, K$^{+}$, Cl￣, 총단백질 및 AST에서 시간경과에 따른 삼투압 조절 능력에 문제가 있는 것으로 보여진다.

• Bulletin of the Korean Chemical Society
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• 제24권4호
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• pp.409-410
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• 2003