Autotrophic carbon dioxide fixation in Acidianus brierleyi.
The autotrophic CO2 fixation pathway in Acidianus brierleyi, a facultatively anaerobic thermoacidophilic archaebacterium, was investigated by measuring enzymatic activities from autotrophic, mixotrophic, and heterotrophic cultures. Contrary to the published report that the reductive tricarboxylic acid cycle operates in A. brierleyi, the enzymatic activity of ATP:citrate lyase, the key enzyme of the cycle, was not detected. Instead, activities of acetyl-CoA carboxylase and propionyl-CoA carboxylase, key enzymes of the 3-hydroxypropionate cycle, were detected only when A. brierleyi was growing autotrophically. We conclude that a modified 3-hydroxypropionate pathway operates in A. brierleyi.
Ishii
M
M
Department of Biotechnology, University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113, Japan.
Miyake
T
T
Satoh
T
T
Sugiyama
H
H
Oshima
Y
Y
Kodama
T
T
Igarashi
Y
Y
D000103:Acetyl-CoA Carboxylase / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000693:Anaerobiosis; D002245:Carbon Dioxide / Q000378:metabolism*; D002262:Carboxy-Lyases / Q000378:metabolism; D002952:Citric Acid Cycle; D003470:Culture Media / Q000737:chemistry / Q000378:metabolism; D019344:Lactic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D043586:Methylmalonyl-CoA Decarboxylase; D009097:Multienzyme Complexes / Q000378:metabolism; D007652:Oxo-Acid-Lyases / Q000378:metabolism; D016943:Sulfolobaceae / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism*
D003470:Culture Media; D009097:Multienzyme Complexes; D002245:Carbon Dioxide; D019344:Lactic Acid; D000255:Adenosine Triphosphate; C031601:hydracrylic acid; D002262:Carboxy-Lyases; D007652:Oxo-Acid-Lyases; C019909:citrate (pro-3S)-lyase; D000103:Acetyl-CoA Carboxylase; D043586:Methylmalonyl-CoA Decarboxylase