• KSBB Journal
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• 제5권1호
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• pp.9-17
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• 1990

Clostridium acetobutyloicum KCTC 1037의 용매 생성조건을 알기 위하여 pH변화와 인산제한의 조건 하에서 회분 배양과 연속 배양을 실시하였다. C. acetobut-ylicum KCTC 1037은 pH5.5나 6.5에서 보다 pH 4.5에서 잘 자라는 호산성이었으며, pH4.5의 진리되지 않은 부티르산이 약 20mM인 조건에서 용매 발효로 전환되었으나, pH5.5의 전리되지 않은 부티트산이 17mM인 조건에서는 용매 발효가 일어나지 않았다. 인산 제한 조건에서 배지에 인산이 KH$_2PO_4$나 $K_2HPO_4$0.1g/l이하인 경우 용매 생성량이 증가하였으나, 생육 속도에는 영향을 미치지 않았다. 인산제한 이단 연속배양에서 pH5.5인 stage1에서는 산생성기가 유지 되었고 한편 pH4.5인 stage2에서는 초기에는 용매가 생성 되었으나 150시간 이후에는 용매의 양이 감소되었으며 산생성기로 전환되는 등 불규칙한 발효 양상을 보였다. 또 pH5.0, 희석율 $0.05h^{-1}$인 stage2에서 전리되지 않은 유기산이 36mM인 조건에서도 용매 발효가 일어나지 않았다. 이러한 결과로서 C.acelobutylicumd의 용매 생성 조건은 산성 pH나 인산 제한 조건외에 균의 최대 에너지 생성을 유지하려는 대사와 관련 되었을 것으로 추측하였다.

• Journal of Microbiology and Biotechnology
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• 제18권5호
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• pp.897-900
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• 2008

Various sequences of pH change were applied in a batch bioreactor to investigate pH shock effects on geldanamycin production by Streptomyces hygroscopicus subsp. duamyceticus JCM4427. In the control culture where the pH was not controlled, the maximum geldanamycin concentration was 414 mg/l. With the pHS1 mode of pH shock, that is, an abrupt pH change from pH 6.5 to pH 5.0 and then being maintained at around pH 5.0 afterward, 768 mg/l of geldanamycin was produced. With pHS2, in which the pH was changed sequentially from pH 6.7 to pH 5.0 and then back to pH 6.0, 429 mg/l of geldanamycin was produced. With pHS3 having a sequential pH change from pH 6.0 to pH 4.0 and then back to pH 6.5 followed by the third pH shock to pH 5.5, no geldanamycin production was observed. Considering that the productivity with pHS1 was about two-fold of that of the control culture with no pH control, we concluded that a more sophisticated manipulation of pH would further promote geldanamycin production.

• 한국환경보건학회지
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• 제24권3호
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• pp.54-62
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• 1998

20 bacterial strains capable of growing on phenol minimal medium were isolated from soil and wastewater by the enrichment culture technique, and among them, one isolate which was the best in the cell growth was selected and identified as Bacillus sp. SH3 by its characteristics. Strain SH3 could grow with phenol as the sole carbon source up to 15 mM, but did not grow in minimal medium containing above 20 mM of phenol. The optimal conditions of temperature and initial pH for growth and phenol degradation were 30$^{\circ}$C and 7.5, respectively. This strain could grow on various aromatic compounds such as catechol, protocatechuic acid, gentisic acid, o-, m-, p-cresol, benzoic acid, p-hydroxybenzoic acid, anthranilic acid, phenyl acetate and pentachlorophenol, and the growth-limiting log P value of strain SH3 on organic solvents was 3.1. In batch culture, strain SH3 degraded 97% of 10 mM phenol in 48 hours. In continuous culture under the conditions of 20 mM of influent phenol concentration and 0.050 hr$^{-1}$ of dilution rate, the treatment rate of phenol was 94%.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.253-256
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• 2003

In batch culture of A. pullulans HP-2001, maximal production of pullulan was 57.90 g/l at 96 hr. The maximal production of pullulan with 76.55 g/l occurred when substituted solution was 10% (w/v) sucrose, 0.25% (w/v) yeast extract and mineral salts. The maximal production of pullulan was 75.00 g/l with a dilution rate of $0.015\;h^{-1}$. Productivity of pullulan in the continuous culture fed with the fresh medium was higher than that fed with the fresh medium without nitrogen source.

• Journal of Microbiology
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• 제35권2호
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• pp.123-126
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• 1997

The aim of the present study was to optimize culture condition for the expression of lipocortin-1$_{1-185}$ in a recombinant of Escherichia coli using batch system. Plasmid (pHT22) carrying lipocortin-1$_{1-185}$ gene was well maintained in the recombinant with the addition of amplicillin as a selection pressures. Optimum temperature was 28$^{\circ}C$ for seed culture and 4$0^{\circ}C$ for main culture and the optimum pH was 7.0. The production of Lipocortin-1$_{1-185}$ was closely associated with cell growth and related to plasmid amplification.

• 한국미생물·생명공학회지
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• 제20권2호
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• pp.207-212
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• 1992

세라티아 균주의 배양으로부터 소염제로 사용되는 세라티오펩티다아제의 생산에 관한 연구를 수행하였다. 여러가지 탄소원, 질소원 및 유도제가 효소의 생산에 미치는 영향을 조사하였는데, 탄소원은 효소의 생산이나 세포성장에 좋지 못한 기질이었으며, 특히 citrate의 경우 균체성장량은 포도당과 거의 동일하였으나, 세라오펩티다제의 생산에 저해효과가 있음이 밝혀졌다. 세라티오펩티다아제는 아미노산인 leucine을 첨가해 주었을 때 그 생산되는 양이 크게 향상되었으며 leucine의 최적 농도는 0.03였다.

• 한국식품영양과학회지
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• 제27권4호
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• pp.639-647
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• 1998

This study was carried out to produce the maltooligosaccharides directly from the culture medium containing high concentration of soluble starch as carbohydrate source by Bacillus cereus IAM 1072. Optimum conditions for the production of maltopentaose and maltooligosaccharides were predicted as 10.62 and 10.92 in C/N ration, 115.74 and 116.51 rpm in agitation speed, 30.19 and 30.9$0^{\circ}C$, respectively. And at these conditions, products of maltopentaose and maltooligosaccharides were 23.23 and 50.33g/L, respectively. From the results of continuous culture for maltopentaose, the productivity increased up to 6.9 times, showing 6.6g/L/hr compared with 0.96g/L/hr batch culture. Maltopentaose showed lower sweetness at 3% concentration representing 1/5 of that sugar. Also, swelling power of maltooligosaccharides was reached to the same point with sugar after fermentation.

• KSBB Journal
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• 제15권6호
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• pp.589-593
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• 2000

Several bacterial strains growing on benzene minimal medium were isolated from soil by enrichment culture, Burkholderia sp. SKK381 was identified and selected. In order to determine the ability of Burkholderia sp. SKK381 to degrade benzene. Changes in substrate concentration, cell growth, and pH were monitored from start-up in bath culture. At 30$^{\circ}C$, 1000 ppm of benzene was degraded 100% within 28hours. Cell growth conditions were best at an initial pH of 7.0 and a benzene concentration of 1000 ppm at 30$^{\circ}C$.

• KSBB Journal
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• 제13권4호
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• pp.438-443
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• 1998

Effects of various environmental factors on cell size index(FCW/DCW) in Thalictrum rugosum. Lithospermum erythrorhizon and Taxus cuspidata plant cell suspension cultures were investigated. Time course change of cell size index were also observed. In batch cultures, FCW/DCW increased according to the decrease of sugar concentration. For short-term experiment within 24 hr, FCW/DCW value could be reduced significantly by increasing sugar concentration. When an osmoticum such as mannitol was added, FCW/DCW converged to a low value. Therefore, it was confirmed that osmolality of the medium was important in determining cell size or water content of the cells. Inorganic salts or treatment with organic solvent also exhibited some effect on the cell size index. However, pH and centrifugal force did not show any influences. On the other hand, it was found that the addition of Pluronic F-68 reduced FCW/DCW. By combining these results effectively, it may be possible to increase the cell concentration in high density culture to a higher extent.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.321-324
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• 2000

Monascus purpureus ATCC 16365에 의한 5-liter 배양기에서 pH 조절을 통하여 세포외로 이차대사물인 수용성 적색소의 생산 증가 현상 와 황색소 보다 적색소로의 대사과정을 촉진시켜 적색소의 생산성을 향상시킬수 있는지의 가능성에 대하여 실험을 수행하였다. 황색소와 적색소의 분석은 UV-Vis spectrophotometer를 이용하여 각각 385nm 와 495nm에서 측정하였다. 실험결과 곰팡이의 최대균체량과 황${\cdot}$적색소를 포함한 총 색소 생산양은 pH 8보다 pH 4.0-5.5인 산성조건에서 2배 및 4배정도 증가하였다. 적색소 및 황색소의 전구물질인 홍색소는 pH 4.0에서 많이 생성되며 또한 홍색소에서 적색소로의 대사과정도 산성 조건 하에서 촉진된다고 보고되었다. 본 실험에서도 같은 경향을 보였으며 또한, 산성 조건 하에서 특히 수용성 적색소가 곰팡이 세포 외로 유출되는 양이 증가하는 경향을 나타내었다.