• 한국미생물·생명공학회지
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• 제28권6호
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• pp.341-348
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• 2000

Selection of high producer strain, optimization of production medium and cultivation in bioreactor system were carried out in order to produce an antifungal substance, PAFS in large amounts which sources and 41 kinds of nitrogen sources, a synthetic medium consisting of fructose(70 g/1) and ammonium sulfate (10g/l) and a complex medium including galactose(30g/l), fructose(20g/l) and cottonseed flour(35g/l) were determined as opti-mized media for PAFS production. In bioreactor studies examining physiological characteristics of the pro- ducer microorganism with the complex medium, typical pattern of diauxic growth was observed as demonstrated by the result that fructose was not used before almost exhaustion on readily utilizable carbon source, galactose. When galactose was supplemented additionally during the fermentation period. PAFS pro-ductivity did no increases any more, indicating that large portion of the added galactose was used for cell growth instead of biosynthesis of the secondary metabolite. It was deduced that PAFS production could be enhananced by employing fed-batch operation in order to overcome the apparent phenomenon of catabolite repression and /or inhibition.

• 한국미생물·생명공학회지
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• 제47권4호
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• pp.614-620
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• 2019

Microalgae have been explored as potential host species for biofuel production. Environmental factors affect algal growth and cellular composition. The effects of several key environmental factors, such as temperature, light, and pH of the medium on the growth and biochemical composition of Scenedesmus obliquus were investigated in this study. The highest growth rate of microalgae was observed at an optimal temperature of 25℃, 150 μmol/(m²·s) light intensity, and pH 10.0. The biochemical composition analysis revealed that the carbohydrate content decreased at lower (20℃) or higher temperature (35℃), whereas the protein and lipid contents increase at these temperatures. The fluctuation of light intensity significantly affected the contents of protein, carbohydrate, and lipid. The protein levels varied greatly when the pH of the medium was below 7.0. The carbohydrate and lipid contents significantly increased at pH above 7.0.

• 한국미생물·생명공학회지
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• 제34권2호
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• pp.150-157
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• 2006

스웨덴 스톡홀름의 항구부근 토양시료로부터 분리한 Bacillus sp. SMMJ-2는 단백질 분해활성이 높은 균주로써 특히 keratinolytic protease 생산성이 우수한 균주이다. 효소생산을 위한 최적 배지조성은 0.7% $K_2HPO_4$, 0.2% $KH_2PO_4$, 1.0% fructose, 1.2% soybean meal(roasted), 그리고 0.01% $Na_2CO_3$ 이었으며 배양초기 pH는 7.0, 배양온도는 30$^{\circ}C$에서 200 rpm조건일 때 효소생산이 가장 우수하였으며 이때의 활성은 105 units/ml/min로 조사되었다.

• Journal of Microbiology and Biotechnology
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• 제30권7호
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• pp.1037-1043
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• 2020

Actinobacillus pleuropneumoniae (APP) is a causative agent of porcine pleuropneumonia. Therefore, the development of an effective vaccine for APP is necessary. Here, we optimized the culture medium and conditions to enhance the production yields of Apx toxins in APP serotype 1, 2, and 5 cultures. The use of Mycoplasma Broth Base (PPLO) medium improved both the quantity and quality of the harvested Apx toxins compared with Columbia Broth medium. Calcium chloride (CaCl₂) was first demonstrated as a stimulation factor for the production of Apx toxins in APP serotype 2 cultures. Cultivation of APP serotype 2 in PPLO medium supplemented with 10 ㎍/ml of nicotinamide adenine dinucleotide (NAD) and 20 mM CaCl₂ yielded the highest levels of Apx toxins. These findings suggest that the optimization of the culture medium and conditions increases the concentration of Apx toxins in the supernatants of APP serotype 1, 2, and 5 cultures and may be applied for the development of vaccines against APP infection.

• 유기물자원화
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• 제12권3호
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• pp.119-125
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• 2004

사탕무즙을 이용한 알콜생산에서 배출되는 증류폐액(sugar beet stillage)을 기질로 고온성 효모인 Candida rugosa를 이용해 단세포단백을 생산 할 때 기질의 최적화와 COD 감소를 연구하였다. 인의 첨가는 실험에 사용된 3가지 모든 시료기질에 꼭 필요한 것으로 나타났고 질소첨가는 기질의 잔당농도가 높을 경우에 필요하였다. 모든 시료에 있어서 인의 첨가는 생균생산율(Biomass production)을 23-61% 까지 크게 높였다. 이에 비해 질소의 첨가는 잔당함량이 높을 경우 생균생산율을 약간 상승시켰으나 질소와 함께 첨가할 경우 90%까지 크게 높였다. COD는 인의 첨가로 인해 26-46%까지 더 감소되었으며 질소와 함께 첨가할 경우 85%까지 크게 감소되었다.

• KSBB Journal
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• 제10권2호
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• pp.113-118
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• 1995

P. spiculispoTum으로부터 생산되는 미생물계변활 성제인 S-acid의 전구체인 O-acid 생산에 영향을 주는 인자들을 검토하고 포도탕 유가배양을 통해 최 척생산조건을 조사하였다. 탄소원으로 oil 등은 별 영향을 마치지 않았고 포도당이 O-acid 생산에 적절 한 탄소원이였으며 무기질소원으로는 $NH_4NO_3$가 높은 O-acid 생산량을 보였다. 미량원소인 $CaCl_2, FeSO_4$등의 첨가에 의해 약 20% 정도의 O-acid가 증가되었으며 용존산소는 포화에 가깡게 유지한 경 우 생산량은 40% 증가되였다. 배양 중 포도당농도는 $50g/\ell$로 유지하는 것이 최적이었으며 Fermentor 에서 포도당의 유가식공급에 의한 경우, 회분식에 비하여 약 60% 의 O-acid 생산증가를 보였다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권1호
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• pp.6-10
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• 2001

The production of chitosan from the mycelia of Absidia coerulea was studied to improve cell growth and chitosan productivity. Culture conditions were optimized in batch cultivation (pH 4.5, agitator speed of 250 rpm, and aeration rate of 2 vvm) and the maximum chitosan concentration achieved was 2.3g/L under optimized conditions. Continuous culture was carried out successfully by the formation of new growth spots under optimized conditions, with a chitosan productivity of 0.052g/L(sup)-1 h(sup)-1, which is the highest value to date, and was obtained at a dulution rate of 0.05h(sup)-1. Cell chitosan concentrations reached about 14% in the steady state, which is similar to that achieved in batch culture. This study shows that for the continuous culture of Absidia coerulea it is vital to control the medium composition.

• 한국물환경학회지
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• 제22권2호
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• pp.193-202
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• 2006

About 99% of microorganisms in the environment are unculturable. However, advances in molecular biology techniques allow for the analysis of living microorganisms in the environment without any cultivation. With the advent of new technologies and the optimization of previous methods, various approaches to studying the analysis of living microorganisms in the environment are expanding the field of microbiology and molecular biology. In particular, real-time PCR provides methods for detecting and quantifying microorganisms in the environment. Through the use of the methods, researchers can study the influence of environmental factors such as nutrients, oxygen status, pH, pollutants, agro-chemicals, moisture and temperature on the performances of environmental processes and some of the mechanisms involved in the responses of cells to their environment. This review will also address information gaps in the analysis of the microorganisms using real-time PCR in the environmental process and possible future research to develop an understanding of microbial activities in the environment.

• 미생물학회지
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• 제40권3호
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• pp.217-220
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• 2004

Cordyceps militaris의 액체 배양시 cordycepin(3'-deoxyadenosine) 생성에 영향을 주는 물리화학적 조건 및 배지 조성의 영향을 조사하였다. 사용된 17종 균주 중에서 C. militaris KCTC 6862, C. militaris KCTC 16932 및 C. militaris DGUM 32003이 우수한 cordycepin생산성을 보여주었다. Cordycepin생산에 적합한 최적 온도와 PH는 각각 $24^{\circ}C$와 pH 6.0-10범위이었다. YM배지에 탄소원으로 glucose를, 질소원으로 tryptone을 각 1% 첨가하였을 매 우수한 cordycepin 생산을 보여주었다. Tryptone을 질소원으로 하는 YMG 액체배지에서 5일간 배양하였을 경우, 39mg/l의 cordycepin의 농도가 측정되었다. 0.1%의 다양한 인산원을 각각 첨가한 결과, cordycepin생산을 저해하였다.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 춘계학술발표회
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• pp.36-36
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• 2018

Soybean is the important crop in Asian countries as protein source, oil production and animal feed. Improving soybean using genetic transformation is the principal tool in nowadays. Developing herbicide resistant transgenic soybean plants through Agrobacterium-mediated transformation has been worked in many previous studied. However, the transformation efficiency is still low. Many attempts try to find the optimum media condition for plant regeneration after infection. After transformation, the plant regeneration is very important condition to promote growth of transgenic plant. In this study, we optimized a regeneration condition for two Korean soybean cultivar, Dawonkong and Pungsannamulkong using cotyledon, cotyledonary nodes and hypocotyl as explant. The results showed that shoot regeneration of cotyledonary nodes on B5 medium containing 2 mg/L 6-benzylaminopurine showed the highest percentage of regeneration in Dawonkong (75.8%) while Pungsannamulkong presented high number of shoots 2.12 shoots per explant. For transformation condition, co-cultivation in 7 days showed a high number of GUS positive expression. Most of explants can survived under media including 5 mg/L of glufocinate which refers phosphinotricin for 2-week selection. Washing with 400 mg/L of cefotaxime in several times and selection in plant regeneration media with 400 mg/L of cefotaxime can prevent bacteria growth, effectively.