|Budget Amount *help
¥12,200,000 (Direct Cost : ¥12,200,000)
Fiscal Year 1999 : ¥2,900,000 (Direct Cost : ¥2,900,000)
Fiscal Year 1998 : ¥9,300,000 (Direct Cost : ¥9,300,000)
In order to clarify carbon dioxide fixation in Archaea, RubisCo from Halofelux, an extremely hahophilic microorganism, and a novel carbon dioxide pathway from Acidianus, an extremely acidophilic microorganism, were investigated in detail.
(A) Through the following experiments, 3-Hydroxypropionate cycle was proposed to be operative in Acidianus ; incorporation of radio active substance, measurement of enzymatic activities, and effect of various inhibitors on the growth. Also, key enzymes for carbon dioxide fixation in the cycle, acetyl-CoA carboxylase and propionyl-CoA carboxylase, were analyzed in terms of molecular weight through detection of biotin protein after electrophoresis. Moreover both carboxylases were purified in terms of chromatography.
(B) In order to obtain good activity of RubisCO from Halofelux, culture condition was investigated on nutrition and aeration. Then, cell-free extract was obtained and was used for the purification of RubisCO by applying the extract onto anion-exchange chromatography and on gel-feltration chromatography. By using the purified enzyme (in terms of chromatography), optimum pH, optimum temperature, thermal stability, and pH stability were measured.