• KSBB Journal
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• 제15권2호
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• pp.195-200
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• 2000

네 종류의 질소원 yeast extract, sodium glutamate, peptone, tryptone과 각 질소원의 농도 및 포도당의 초기 농도가 해양 미생물 Thraustochytrium aureum ATCC 34304의 linoleic acid 생산성에 미치는 영향을 규명하여 다음의 결과를 얻었다. 초기 당 농도를 10 g/L로 하고 질소원으로는 sodium glutamate를 사용하였을 때 균체 단위 질량에 대해 생성된 지질의 중량 분율이 최대값 0.302 mg/g를 나타내었으며, 균체에 대한 linoleic acid 중량 분율도 8%로 최대값을 나타내었다. Lino-leic acid의 생성속도는 질소원으로 peptone과 sodium gluta-mate를 사용하였을 경우 다른 질소원으로 peptone과 sodium gluta-mate를 사용하였을 경우 다른 질소원을 사용하였을 때 보다 2.5 배까지 높은 수치를 나타내었다. 초기 당 농도가 증가하면 linoleic acid의 생산성은 상승하나 당 농도 30 g/L 이상에서는 그 상승폭이 대단히 완만하였다. 초기 당 농도가 30 g/L 경우 질소원으로 peptone을 사용하였을 때는 linoleic acid의 생산량이 200 mg/L, sodium glutamate를 사용하였을 때는 130 mg/L를 나타내었다. 질소원의 농도가 증가하면 균체 내에 생성되는 지질의 양도 증가하는 경향을 나타내었다. 질소원이 sodium glutamate인 경우 농도 1 g/L까지는 지질의 함량이 뚜렷한 증가현상을 나타내었으나 농도 1.0 내지 2.0 g/L 이상에서는 질소원의 농도가 증가하면 지질의 생성량이 감소하였다.

• 한국미생물·생명공학회지
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• 제24권4호
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• pp.404-407
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• 1996

The effects of carbon sources on vancomycin production were investigated using Nocardia orientalis CSVC 3300. Among carbon sources tested, glucose, maltose and fructose were effective for the production of vancomycin. Glucose was favored for growth, but decrease the production of vancomycin at the concentration above 7.5%. In comparison, maltose did not decrease the production of vancomycin up to the concentration of 20%. When the mixture of glucose and maltose was used in the ratio 1:3 to 1:4, the highest production of vancomycin was achieved. When glucose concentration was set at 3.0%, catabolite repression could not be observed up to total sugar concentration of 16.0%. Fermentation was carried out using commercial hydrolyzed starch composed of glucose, maltose, maltotriose and maltotetraose, The initial glucose concentration was set at 3.0% and subsequent oligosaccharide consumption was monitored by checking their supernatant with HPLC. During initial cultivation for 38 hour, glucose was the sole carbon source leading to rapid growth. After cell growth stopped, the maltose and glucose concentrations increased due to degradation of maltotriose and maltotetraose, but glucose level was maintained at around 3.0%. After 70 hour fermentation, maltose slowly converted to glucose, and vancomycin production continued during the period.

• 한국환경보건학회지
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• 제23권3호
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• pp.1-6
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• 1997

This research was conducted in the laboratory to investigate an alternative of Copper(Cu) removal from an heavymetal wastewater using the electrochemical precipitation(ECP) process. The ECP unit consisted of an electrolytic cell made of Titanium plate and Steel plate representing anode and cathode. The DC power source applied to the ECP unit had electrical potential(E) of 50$\pm$ 1V, respectively. The synthetic wastewater used in the experiments contained Cu in the 10 mg/l concentration and the electrode separation were 2, 3, 4 cm and the initial pH were 3, 6, 9, 12, and electrolytic concentration were 0.005, 0.0125, 0.025, 0.0375 mole, and the real heavymetal wastewater used in the experiments. From the experiment for removal efficiency according to pH variation, the low pH area doesn't give the coagulation effect by Ti(OH)$_4$ because process interfere with the coagulation and oxidation reaction, therefore the optimum pH was 4-7. The removal rate was 97.75% after the lapse of 30 minutes when copper concentration and electrolytic concentration were respectively 10 mg/l and 0.025 mole. The removal rate was 96.41% after the lapse of 30minutes when the real heavymetal wastewater used. The optimum consumption of power showed 27KWh/m$^3$ when copper concentration, electrolyte concentration and cell potential were respectively 10 mg/l, 0.025 mole and 50$\pm$ 1 Volt.

• The Korean Journal of Ecology
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• 제18권1호
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• pp.17-30
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• 1995

The growth of Scenedesmus quadricauda (Trup.) Breb. is enhanced by methylyoxal (MG), a general inhibitor of cell division, at threshold concentration in conjunction with reatment timing relative to growth stage. The stimulatory effect of MG on algal cell growth was most significant with 2.27-fold of untreated algal culture in cell number when 0.5 mM of MG was added to the algal culture at the beginning of logarithmic phase with an initial MG concentration of 0.535 mg $MG/10^6cell$. A Specific growth rates (SGRs) of MG-treated cultures were rapidly increased at the beginning of logarithmic phase with 1.89-fold of untreated algal culture. Cultures inoculated with high cell numbers of 2.4 to 4.8 X $10^4$ cells/ml were less sensitive to 0.5 mM of MG treatment. The algal cell division was ranged from 0.392 to 0.924 mg MG/106 cell. If the cell number of an algal culture at the time of inoculation was low (0.6 X $10^4$ cells/ml) and MG was added before logarithmic phase, the cell number of 0.5 mM of MG-treated cultures were lower than those of controls. In algal cultures treated with high concentrations of MG (1.0 mM and 2.0 mM), the algal growth was inhibited. Photosynthetic rate of growth-enhanced algal by 0.5 mM of MG was significantly higher than that of untreated or 1.0 mM of MG-treated algal cell, while there was no significant difference among those groups in respiratory rate. Pyruvate concentration in 0.5 mM of MG-treated culture was incrcased agter methylglyoxal trcatment.

• Toxicological Research
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• 제14권4호
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• pp.507-513
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• 1998

The purpose of this study was to clarify the effect of silica on cytosolic free calcium mobilization and cell injury in primary cultured rat hepatocytes. Cytosolic free calcium concentration ([Ca$^{2+}$]) was measured employing calcium sensitive fluorescent dye, Fura-2 / AM, and cell injury was evaluated by determination of cellular ATP contents. Silica increased [Ca$^{2+}$], in a concentration-dependent manner in hepatocytes (10$^{-5}$ ~10$^{-2}$ M). Silica caused a biphasic increase in [Ca$^{2+}$], which was composed of an initial rapid rise and following sustained phase. $Ca^{2+}$ removal from the medium resulted in abolishment of initial and sustained phase of silica (10$^{-2}$ M)-induced [Ca$^{2+}$], in hepatocytes. The pretreatment with nifedipine (1 $\mu$M) attenuated silica-induced [Ca$^{2+}$], increases. Silica decreased cellular ATP contents in a dose-dependent manner. This silica-induced cell injury was attenuated by the pretreatment with EGTA (100 $\mu$M) and nifedipine (1 $\mu$M). This study suggests that the elevation of [Ca$^{2+}$], caused by silica may be due mainly to influx through a plasma membrane $Ca^{2+}$ channel and hepatotoxicity by silica relate with alteration of calcium homeostasis.ium homeostasis.

• KSBB Journal
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• 제21권5호
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• pp.331-335
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• 2006

참당귀(Angelica gigas Nakai) 현탁세포의 면역 증강성 다당의 생산을 증진시키기 위하여 초기 당농도와 생장조절제인 2,4-D의 농도를 변화시켰다. 당의 농도를 높일수록 세포의 생장과 ECP의 생산은 각각 1.6배, 1.1배 증가하여 효과적이었다. 2,4-D는 첨가하지 않은 것이 세포의 생장이 대조군에 비해 1.2배 높았지만, ECP의 생산의 경우 2mg/L 2,4-D를 첨가한 경우 대조군에 비해 10% 이상 더 생산되었다. 또한 배양 중 여러 가지의 elicitor를 첨가함으로써 ECP의 생산을 증진시키기 위하여 fungal elicitor들을 처리한 결과 Verticillium dahliae 90 mg/L을 배양 4일째에 처리한 경우 세포의 생장을 다소 저해시킨 반면, ECP 생산량이 1.7배나 증가함을 확인하였다.

• 한국수소및신에너지학회논문집
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• 제21권6호
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• pp.507-512
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• 2010

The effect of catholyte to anolyte amount ratio on the electrodialysis cell performance for HI concentration was investigated. For this purpose, the electrodialysis cell was assembled with Nafion 117 as PEM membrane and activated carbon fiber cloth as electrodes. The initial amount of catholyte was 310 g and that of anolyte varied from 1 to 3 of amount ratio. The calculated electro motive force (EMF) increased with time and the increment enhanced as the amount ratio of catholyte to anolyte decreased. The mole ratios of HI to $H_2O$ (HI molarity) in catholyte were almost the same and exceeded pseudo-azeotropic composition for all amount ratios after 2 h operation. The HI molarity continuously increased with time for 10 h operation. The mole ratio of $I_2$ to HI decreased in catholyte but increased in anolyte. The increment of mole ratio of $I_2$ to HI in anolyte rose as the amount ratio of catholyte to anolyte decreased. In case of 1:1 amount ratio, the cell operation was stopped for the safety at approximately 6 h operation, since the mole ratio of $I_2$ to HI reached solubility limit. The cell voltage of the electrodialysis cell increased with time and the rate of increase was high at low amount ratio. This suggests that the amount ratio of catholyte to anolyte not only crucially influences the cell voltage, but also cell operation condition.

• 한국미생물·생명공학회지
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• 제19권4호
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• pp.390-397
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• 1991

효모를 Ca-alginate에 고정화하여 회분발효에서 glucose로부터 에탄올을 생산하여 다음의 결과를 얻었다. 100g wet weight/l($4.3 \times 10^9$ cell/l)의 효모를 pH 7.0, 2% 농도의 Ca-alginate에 고정화하였다. 10 beads volume이 에탄올 생산에 최적이었고 30일 (720 시간) 동안 bead의 수명이 지속되었다. 회분식 발효에서 온도안정성은 고정화 효모의 경우 30~$40^{\circ}C$였으며 free cell의 경우 30~$37^{\circ}C$였다. pH 안정성은 pH 4.0~9.0였으며, 에탄올생산 최적 당농도는 15%였다. 최적조건에서 에탄올수율은 0.45, 생산된 에탄올 농도는 67.6g/l 그리고 에탄올 생산성은 1.99g/l.h로 각각 나타났다.

• 생명과학회지
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• 제16권6호
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• pp.877-883
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• 2006

발효산업에 많이 사용되는 A. pullulans를 사용하여 독성 중금속인 납에 대한 제거량을 살펴보았다. 용액 중의 중금속을 제거할 때 A. pullulans가 다른 중금속에 비해 납에 대한 선택성이 우수하였으며 $40^{\circ}C$에서 최대 흡착량을 나타내었으며 또한 최적 pH가 9일 경우에 흡착량이 증가하였다. 초기납의 농도가 96 mg/l 인 경우에 단위 미생물당 흡착량이 120mg/g로 짧은 시간내에 많은 양의 납을 제거함을 알 수 있었다. 그리고 약 200 mg Pb/g cell dry weight 정도가 최대 납 흡착량인 것으로 나타났다. 그리고 미생물의 보존기간에 따라 세포외 고분자물질의 분비가 증가하여 납 흡착량을 증가시켰으며, Freundlich 모델에 잘 적용되었다. 그리고 살아있는 상태가 사멸된 상태에서 평형흡착량은 약 2배 정도 흡착능이 우수함을 알 수 있었으며, 그에 따라서 초기 흡착속도도 살아있는 상태가 사멸된 상태보다 훨씬 빠른 것을 알 수 있었다.

• KSBB Journal
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• 제11권1호
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• pp.65-70
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• 1996

본 연구에서는 글루콘산 및 그 유도체 생산에 관 한 기초자료를 얻기 위하여 일차적으로 글루콘산나 트륨의 생산조건에 대하여 실험하였다. 발효가 진행 됨에 따라 생성되는 글루콘산을 수산화나트륨을 이 용하여 중화시킴으로써 글루콘산나트륨으로 전환하였으며 이때 초기 당농도 및 pH의 영향을 정량적으 로 검토하여 생산성을 비교하였다. Aspergillus niger를 이용한 글루콘산나트륨 발효 에서 초기 농도 및 초기 pH가 발효 특성치에 미치 는 영향은 실험 결과를 종합하면 최대비생성속도는 초기 당농도 110g/$\ell$ 에서 $0.20hr^{-1}$로서 가장 높은 값을 나타내였으며 균체 빛 글루콘산나트륨 수율은 저농도 기질인 당놓도 26/$\ell$. 에서 0.24, 0.49로서 최대값을 나타내였고 잔당 농도는 5g/$\ell$. 미만이었다. 또한 총괄 글루콘산나트륨 생산성은 고농도 기질인 11Og/$\ell$에서 1.18g/$\ell$/hr로서 가장 높았다. 그리고 발효를 위한 최척 pH는 5.5이었다. 산업체 발효조 척용, 간헐 첨가 회분배양(intermittent feeding fed-batch)의 결과, 36시간 경과 후의 글루콘산나트륨 의 농도는 255g/l 이였으며 산업적 생산이 가능한 수준이었다.