• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.782-786
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• 2009

Thiocapsa roseopersicina NCIB 8347은 purple sulfur bacteria이며 광합성종속영양 조건에서는 nitrogenase 효소계가 유도되어 질소를 고정하며, 수소를 발생한다. 또한 광합성독립영양 조건에서는 hydrogenase 효소계가 유도되어 3~4개 종류의 특성이 다른 hydrogenase가 membrane에 결합되어 있거나, cytoplasma에 존재하며, 이 중의 일부는 산소농도와 온도의 상승에도 비교적 안정하다. 본 연구에서는 T. roseopersicina NCIB 8347이 광합성종속영양 조건에서 수소를 생산할 수 있는 제반 배양조건을 최적화하고, nitrogenase와 일부 hydrogenase역가를 측정하여 purple non-sulfur bacteria, Rhodobacter sphaeroides KD131의 nitrogenase와 비교하여 수소생산을 최적화하였다. 할로겐램프를 8-9 $Klux/m^2$로 조사할 때와 배양온도 $26{\sim}30^{\circ}C$, 배양시간 72시간에서 균체 성장과 수소생산이 가장 높았다. T. roseopersicina NCIB 8347는 광합성 독립영양, 종속영양 조건에서 모두 성장 할 수 있었다.

• 한국수소및신에너지학회논문집
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• 제16권3호
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• pp.219-228
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• 2005

Fermentative strict anaerobic bacterium, Clostricium butyricum NCIB 9576 (Cl. butyricum) and purple sulfur phototrophic bacterium, Thiocapsa roseopersicina NCIB 8347 (T. roseopersicina) were compared on their temperature and oxygen stabilities of cytoplasmic hydrogenases. Cell growth phase and the specific activities of evolution $H_2ase$ were related for both strains, exhibiting the highest cytoplasmic $H_2ase$ activities during the logarithmic growth phases which were 4 and 18 hrs after the incubation for Cl. butyricum and T. roseopersicina, respectively. The optimum temperatures for the growth of Cl. butyricum and T. roseopersicina were 37$^{\circ}C$ and 27$^{\circ}C$, respectively, while those for $H_2$ evolution of cytoplsmic hydrogenases prepared from Cl. butyricum ($C-H_2ase$) and T. roseopersicina ($T-H_2ase$) were 45$^{\circ}C$ and 65$^{\circ}C$, respectively. $T-H_2ase$ was more thermo-stable than $C-H_2ase$. $T-H_2ase$ retained its full activity for 5 hrs at 50$^{\circ}C$ and retained 90% of its original activity for 5 hrs at 60$^{\circ}C$, however, $C-H_2ase$ lost its activity drastically at 50$^{\circ}C$. The optimum pHs for $H_2$ oxidation of $C-H_2ase$ and $T-H_2ase$ were 9.0 and 7.5 respectively. The both enzymes showed maximum $H_2$ evolution activity at pH 7.0. Under the aerobic condition, 80% of $T-H_2ase$ activity was retained for 10 hrs at 30$^{\circ}C$, and 50% of activity was still remained after 6 days at the same experimental conditions. But the $C-H_2ase$ was labile to oxygen and lost its activity immediately after the exposure to air.

• KSBB Journal
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• 제20권6호
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• pp.413-417
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• 2005

홍색유황세균, Thiocapsa roseopersicina가 광합성 종속영양상태에서 수소를 생산하기 위한 여러 가지 인자 중에서 광원, 광세기, 배양온도의 영향을 실험하였다. 또한 균체의 성장곡선과 아울러 수소 생산과 소비에 영향을 주는 효소 역가의 변화를 측정하였다. 할로겐등과 형광등을 사용하여 균체성장과 수소생산을 관찰한 결과 배양 48시간 만에 균체성장은 할로겐등과 형광등을 $7.5{\sim}10$ klux로 조사할 때 각각 1.38 및 1.41 g-DCW/L로 가장 높은 균체 성장을 보였고, 수소생산성은 할로겐등과 형광등 10 klux일 때 각각 0.90 및 0.48 $ml-H_2/mg$-dcw를 보여 할로겐등 10 klux일 때 가장 높은 수소생산성을 보였다. 최적 수소생산 온도는 $26^{\circ}C$이었고, $30^{\circ}C$ 이상에서는 수소생산이 감소하였다. $30^{\circ}C$에서 할로겐 램프로 $8{\sim}9$ klux를 조사하면서 photoheterotrophic 조건으로 배양할 때 T. roseopersicina NCIB 8347 세대시간은 약 4.2시간이었다. 수소는 성장대수기 중간인 18시간부터 발생하여 succinate가 모두 소비되는 45시간까지 발생하였고, 그 이후는 더 이상 생산되지 않았다. 그러나 배양시간이 연장되면서 발생한 수소는 시간이 경과함에 따라 감소하였다. 또한 본 배양 조건에서 발생한 수소생산은 nitrogenase에 의한 것으로 사료되었다.

• 한국수소및신에너지학회논문집
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• 제19권2호
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• pp.124-131
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• 2008

Crude cytoplasmic fraction of phototrophic purple sulfur bacterium, Thiocapsa roseopersicina NCIB 8347, were initially prepared and purified by sonication, ultracentrifugation, ammonium sulfate fractionation and heat-treatment and it has been previously reported. Using various applications of chromatography far the purification of membrane-bound and soluble hydrogenases from heat-treated enzyme fraction were studied at present report. When the heat-treated enzyme preparation was applied to the anion column chromatography using Q-sepharose, Fraction I and II, which were extracted with the KCl 0-0.5 M gradient, showed the specific evolution hydrogenase activity 3.86 and 2.27 U/mg-protein respectively. Specific hydrogenase activitys of Fraction I and II were further increased to 4.35 and 7.46 U/mg-protein for Fraction I and to 2.49 and 4.41 U/mg-protein fur Fraction II respectively, when hydrophobic interaction column, Phenyl superose, and anion exchange column, Mono-Q, were applied. Size exclusion chromatography using superdex 200 concentrated the hydrogenase Fraction I and II to 9.19 and 7.84 U/mg-protein respectively at the final step of purification.

• 한국수소및신에너지학회논문집
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• 제17권4호
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• pp.371-378
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• 2006

Effect of $(NH_4)_2SO_4$ precipitation and heat-treatment on hydrogenase which was extracted from the cytoplasmic fraction of the phototrophic purple sulfur bacterium Thiocapsa roseopersicina NCIB 8347 was studied. Crude enzyme extract was prepared by centrifugation($28,000{\times}g$, $400,000{\times}g$) after sonication of cells grown under photosynthetic condition for 96 hrs. Various conditions of $(NH_4)_2SO_4$ precipitation and heat-treatment were examined and the effect of protein concentration was analyzed by SDS-electrophoresis between the treatments. Optimum conditions for $(NH_4)_2SO_4$ precipitation and heat-treatment for evolution hydrogenase activity were 40-60% saturation and $60^{\circ}C$ for 20 min, respectively, which exhibited the specific hydrogenase activity of 0.78 U/mg-protein. Specific hydrogenase activity was decreased to 31.6% when the heat-treatment at $60^{\circ}C$ increased from 20 min to 5 hrs.

• Journal of Microbiology and Biotechnology
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• 제16권8호
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• pp.1210-1215
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• 2006

The properties related to the temperature and oxygen stability of the cytoplasmic hydrogenases from the fermentative strict anaerobic bacterium, Clostridium butyricum NCIB 9576 (Cl. butyricum), and purple sulfur phototrophic bacterium, Thiocapsa roseopersicina NCIB 8347 (T. roseopersicina), were compared. The optimum temperatures for the growth of Cl. butyricum and T. roseopersicina were 37$^{\circ}C$ and 25$^{\circ}C$, respectively, whereas those for the H$_2$ evolution of the cytoplasmic hydrogenases prepared from Cl. butyricum (C-H$_2$ase) and T. roseopersicina (T-H$_2$ase) were 45$^{\circ}C$ and 65$^{\circ}C$, respectively. The T-H$_2$ase was more thermostable than the C-H$_2$ase and retained its full activity for 5 h at 50$^{\circ}C$ under anaerobic conditions and 90% of its activity at 60$^{\circ}C$, whereas the C-H$_2$ase lost its activity drastically at 50$^{\circ}C$. The optimum pHs for H$_2$ oxidation of the C-H$_2$ase and T-H$_2$ase were 9.0 and 7.5, respectively. Both enzymes showed a maximum H$_2$ evolution activity at pH 7.0. Under aerobic conditions, 80% of the T-H$_2$ase activity was retained for 10 h at 30$^{\circ}C$, and 50% of the activity remained after 6 days under the same experimental conditions. However, the C-H$_2$ase was labile to oxygen and lost its activity immediately on exposure to air. Therefore, these properties of the T-H$_2$ase are expected to be advantageous for application in in vitro biological H$_2$ production systems.