• Applied Biological Chemistry
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• 제42권3호
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• pp.193-198
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• 1999

키토산분해효소를 분비하는 세균 Bacillus sp. P16의 최적배양조건을 조사하였다. 키토산분해효소 생산을 위한 최적 탄소원은 0.5%분말 키토산이었으며, 최적 질소원은 1% tryptone이었다. 최적온도는 $37^{\circ}C$였으며, 최적 초기 pH는 7.0이었다. 이 조건에서 $60{\sim}$72시간 배양하였을 때 효소 생산이 최고에 도달하였으며, 효소활성은 약 30% 증가하였다. 이를 발효조에서 배양하면 $6{\sim}$12시간 배양으로 최대활성에 도달하였으며, 효소 생산은 약 100% 증가하였다.

• 한국미생물·생명공학회지
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• 제28권3호
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• pp.156-160
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• 2000

국내 부존자원인 inulin을 이용하여 fructose syrup 또는 oligosacharide를 생산한는 효소를 발굴하기 위하여 전국적으로 토양 등 시료를 채취하여 inulinase 생성 미생물을 분리하였으며 inulinase 활성이 높은 96-1 균주를 동정한 결과 그람 양성균인 Arthrobacter protophormiae/ramosus인 것으로 잠정 동정되었다 Inulinase 생산을 위한 최적 배지는 무기염류 기초배지에 각 1%(w/v)의 inulin tryptone. $NH_4Cl$이 함유된 배지였으며 퇴적 발효조건은 $35^{\circ}C$초기 pH 7.5 통기량 1vvm 교반속도 200rpm이었다.

• 대한미생물학회지
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• 제17권1호
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• pp.35-41
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• 1982

Enterotoxigenk E. coli is one of the major causative agents of the infantile diarrhea and traveler's diarrhea. The heat-labile enterotoxin is thought to be a virulence factor in the pathogenesis of the diarrhea and to be a marker for identification of the enterotoxigenic E. coli from non pathogenic E. coli. Therefore knowledge about the heat-labile enterotoxin is essential not only for understanding the pathogenesis but also for the diagnosis of the diarrhea. However the in-vitro heat-labile enterotoxin production is reported to be greatly affected by the cultural condition. In this regards, this study was designed to know the optimal conditions for the production of the heat-labile enterotoxin by assaying the permeability factor in the 18 hours culture supernatant of E. coli 08K25(B2) H9 and of E. coli 015 H11. Results obtained were summerized as follows: 1. Amounts of heat-labile enterotoxin produced were greater at initial pH 8.5 than at 7.0 of CYES-2 broth culture. However, the bacterial growth itself was more abundant at 7.0 than at 8.5. 2. Heat-labile enterotoxin per unit volume of culture supernatant was greater at shaking culture than at standing culture condition, but ratio of the enterotoxin produced over the unit mass of E. coli calculated was greater at standing culture than shaking culture condition, indicating that the greater yields of the toxin produced at shaking culture was due to increase in E. coli cell mass compared to the standing culture condition: 3. The enterotoxin produced in the lincomycin(128 microgram/ml) supplemented media was 5 or 11 times greater on the basis of enterotoxin per unit mass of E. coli, compared to the lincomycin-non-supplemented media, indicating that lincomycin itself increases the enterotoxin production. 4. Treatment of 18 hours culture of E. coli with polymyxin B(0.2 mg/ml) for 1 hour increased the yields of enterotoxin amounting to 2 or 5 times of the non-treated control cultures.

• KSBB Journal
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• 제14권3호
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• pp.351-357
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• 1999

A marine bacterium Bacillus cereus ASK202, agarase producing strain, was treated with some mutagenic agents, ultraviolte(UV), 1-methyl-3-nitro-1-nitrosoguanidine(NTG), and ethyl methane sulfonate(EMS), several times for the increasing of the agarase production After mutagen treatment, we isolated one mutant strain treated with NTG showed the highest stability and agarase productivity and named as Bacillus cereus ASK202-N3. This Bacillus cereus ASK202-N3 strain was well grown in the modified marine medium containing 0.5%(w/v) agar, 0.3%(w/v) yeast extract, and 5.0%(w/v) NaCl, and the optimal initial pH, temperature and culture time were 7.8, $25^{\circ}C$ and 32h, respectively. In the optimal culture conditions, the agarase production was increased to 5.3 fold(850units/L) compared to that of the wild type.

• 한국미생물·생명공학회지
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• 제26권2호
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• pp.130-136
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• 1998

참당귀 세포(Angelica gigas H4)를 현탁배양하여 면역 증강성 다당을 생산하기 위한 최적배지 설계 및 생산조건 최적화 연구를 수행하였다. 우선 세포의 성장에 가장 좋은 배지로서 Schenk and Hildebrandt(SH) 배지를 선택하여 배양한 결과 $25^{\circ}C$, 암배양조건에서 각각 15.8g DCW/l와 0.85 g/l의 세포 및 다당을 얻을 수 있었다. 한편 다당 생산용 배지의 개발을 위하여 여러 가지 식물세포배양용 배지 중에서 다당 생산능이 가장 높은 배지로서 Gamborg B5 배지를 선정하였으며 B5 배지를 변형하여 면역증강성 다당생산을 위한 최적배지(PPM)를 개발하였다. 그리고 최적배지를 이용한 당귀 세포증식과 다당 생산을 위한 최적 pH는 6.0-6.5, 배양온도는 $20^{\circ}C$, 그리 고 광조건보다는 암조건이 좋은 것으로 밝혀졌다. 상기 최적조건에서의 최대 세포증식과 다당생산은 각각 14.8 g/l, 1.5 g/l 이었다.

• 공업화학
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• 제20권3호
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• pp.285-289
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• 2009

최근 지구온난화 및 식량문제에 대한 관심이 증대되면서 그 해결책으로 미세조류에 대한 많은 연구가 이루어지고 있다. 특히 광합성 미세조류 Spirulina platensis는 이산화탄소를 고정할 수 있으며, 영양적 가치가 우수하여 많은 관심을 받고 있다. 본 연구에서는 Spirulina platensis NIES 39의 대량 배양을 위한, 배양온도, 초기 pH, 조도, 탄소와 질소원의 농도 등의 요인에 대한 최적 조건을 확립하고자 하였다. 배양 온도 $35^{\circ}C$에서 초기 pH 9.5, 조도 4500 lux에서 건조균체중량 2.10 g/L, 클로로필 함량 29.53 mg/L로 가장 우수한 결과를 나타내었으며, 이때의 탄소원과 질소원의 농도는 각각 16.8 g/L $NaHCO_3$, 2.5 g/L $NaNO_3$이었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권3호
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• pp.254-261
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• 2005

The over-expression of Bcl-2 has greatly improved the culture period, specific growth rate, and maximum viable cell density of NS0 cells culture under low serum condition. Further analysis of these data suggests that a saturation model of the Monod type can be used to represent the relationships of specific growth rate and initial serum concentration. The ${\mu}_{max}$ and $K_s$ for the Bcl-2 cell line is $0.927day^{-1}\;and\;0.947\%(v/v)$ respectively, which are $21\%$ greate and $7\%$ lower respectively than its control counterpart. Study on the amino acid supplementation revealed that Bcl-2 cell lines possess greater improvement in the specific growth rate and maximum viable cell density compared to the control cell lines. A further increase in the amino acid supplementation has resulted a $17\%$ decrease in specific growth rate and no improvement in maximum viable cell density in the control culture. However, the Bcl-2 cell line exhibited a better growth characteristic in this culture condition compared to that of control cell lines. The higher specific growth rate and maximum viable cell density of the Bcl-2 cell line in medium fortified with serum and MEM EM suggested a more efficient nutrient metabolism compared to that in the control cell line. The low serum and amino acid utilisation rate and the higher cell yield may prove to be important in the development of serum/protein free culture.

• 한국미생물·생명공학회지
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• 제28권6호
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• pp.349-354
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• 2000

Culture conditions and nitrogen sources were optimized for production of erythritol, a natural sweetener, by Candida magnoliae M26. The optimal culture conditions were found to be culture temperature of $28^{\circ}C$, initial pH of 7, aeration of 1 vvm and agitation speed of 500 rpm in a 2.5 1 jar-fermentor. Glucose was chosen as the best carbon cource bsed on cell growth and erythritol productivity. Kight steep water(LSW) and corn steep liquor (CSL) which are by-products in starch processing from corn were tested as a nitrogen source substitute for yeast extract. The use of either LSW or CSL did not change the fermentation performance. The experimental results using LSW and CSL showed 1.5 times higher in cell growth and almost the same value in erythritol productivity com-pared with the control fermentation using yeast extract as a nitrogen source. These results suggested that either LSW of CSL could be used as a nitrogen source in a large-scale fermentation for erythritol production.

• 한국미생물·생명공학회지
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• 제17권3호
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• pp.231-235
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• 1989

부착성 동물세포인 recombinant human embryonic kidney cell line 293을 5% FBS가 함유된 DME/F12(3:1) mixture 배지에서 배양할 경우 static culture에서와는 달리 미립담체 배양에서는 낮은 부착효율과 spreading의 저해현상이 관찰되었다. Cell line 293의 미립담체 배양에 있어서 배지내의 serum은 세포의 미립담체에 대한 부착속도(attach-ment rate)를 감소시킬 분만 아니라 세포의 증식을 저해한다는 사실을 확인하였다. 이러한 경우, conditioned microcarrier를 이용함으로써 미립담체로부터 세포의 탈착을 어느 정도 막을 수 있었다. 특히 autocrine growth factor를 생성하는 hepatoma cell line인 HpG 2 cell을 배양하여 얻은 conditioned medium을 serum-free medium에 첨가하여 사용함으로써 세포의 정상적인 성장 분만 아니라 growth-stimulation을 유도할 수 있었다.

• 한국초지조사료학회지
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• 제15권3호
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• pp.157-163
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• 1995

The objective of this study is to obtain the basic data for investigating the effects of organic reserves on winter survial or regrowth yield. Dry matter, nitrogen and non-structural carbohydrate content of plants grown under $5^{\circ}C$ or $20^{\circ}C$ of culture temperature during 25 days were investigated. The dry matter content of leaves and roots were significantly reduced under $5^{\circ}C$ compared with $20^{\circ}C$culture condition. Comparing with the dry matter per plant under $20^{\circ}C$, those in leaves and roots under $5^{\circ}C$ decreased to 25% and 10%, respectively, after 25 days of temperature treatment. Total nitrogen content in leaves under $20^{\circ}C$ and $5^{\circ}C$ increased to 68% and 39% compared to the initial lenel(day O), respectively, during 25 days after temperature treatment, Nitrogen content in roots highly increased under 5 C while there was a little change under $20^{\circ}C$ condition. The nitrogen contents in roots under $5^{\circ}C$ and $20^{\circ}C$ were 39.0 and 30.8mgJg DM, respectively, after 25 days of temperature treatment. Total contents of soluble carbohydrate in both leaves and roots under $5^{\circ}C$ were higher than those under $20^{\circ}C$ condition. After 25 days of temperature treatment under$5^{\circ}C$ , their contents in leaves and roots were 1.4 and 2.0 times higher than those of under $20^{\circ}C$ condition. Stach atent in roots under $20^{\circ}C$ was less changed, while thatof under $5^{\circ}C$ greatly increased from 64.8 to 178.7mglg DM duling 25 days. 'Ihese results clearly showed that an accumulation of both nitrogen and non-structural carbohydrate in the plants occured under low temperature condition.e condition.