Comparison of hydrogenases from Clostridium butyricum and Thiocapsa roseopersicina
作者单位：Biomass research center Korea Institute of Energy Research. 71-2 Jang-dong. Yuseong-gu Daejeon 305-343 Korea
会议名称：《第8届亚洲氢能会议》
会议日期：2005年
学科分类：081702[工学-化学工艺] 08[工学] 0817[工学-化学工程与技术]
摘 要：Properties on temperature and oxygen stability of cytoplasmic hydrogenases from fermentative strict anaerobic bacterium, Clostricium butyricum NCIB 9576 (Cl. butyricum) and purple sulfur phototrophic bacterium, Thiocapsa roseopersicina NCIB 8347 (T. roseopersicina) were compared. The optimum temperatures for growth of Cl. butyricum and T. roseopersicina were 37℃and 25℃, respectively, while those for H2 evolution of cytoplsmic hydrogenases prepared from Cl. butyricum (C-Hase) and T. roseopersicina (T-H2ase) were 45℃and 65℃, respectively. T-Hase was more thermo-stable than C-H2ase. T-H2ase retained its full activity for 5 hrs at 50℃and retained 90% of its original activity for 5 hrs at 60℃, however, C-Hase lost its activity drastically at 50℃. The optimum pHs for H2 oxidation of C-H2ase and T-Hase were 9.0 and 7.5 respectively. The both enzymes showed maximum H2 evolution activity at pH 7.0. Under the aerobic condition, 80% of T-Hase activity was retained for 10 hrs at 30℃, and 50% of activity was still remained after 6 days at the same experimental conditions. But the C-Hase was labile to oxygen and lost its activity immediately after the exposure to air.