Ishii M, Miyake T, Satoh T, Sugiyama H, Oshima Y, Kodama T, Igarashi Y
Department of Biotechnology, University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113, Japan.
Arch Microbiol. 1996 Dec;166(6):368-71. doi: 10.1007/BF01682981.
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.
通过测量自养、兼养和异养培养物中的酶活性，对兼性厌氧嗜热嗜酸古细菌布氏嗜酸菌（Acidianus brierleyi）中的自养二氧化碳固定途径进行了研究。与已发表的关于布氏嗜酸菌中还原性三羧酸循环起作用的报告相反，未检测到该循环的关键酶ATP：柠檬酸裂解酶的酶活性。相反，仅当布氏嗜酸菌自养生长时，才检测到3-羟基丙酸循环的关键酶乙酰辅酶A羧化酶和丙酰辅酶A羧化酶的活性。我们得出结论，布氏嗜酸菌中存在一种经修饰的3-羟基丙酸途径。
