Sakuraba Haruhiko, Goda Shuichiro, Ohshima Toshihisa
Department of Biological Science and Technology, Faculty of Engineering, The University of Tokushima, Tokushima 770-8506, Japan.
Chem Rec. 2004;3(5):281-7. doi: 10.1002/tcr.10066.
Hyperthermophiles are a group of microorganisms that have their optimum growth temperature above 80 degrees C. More than 60 species of the hyperthermophiles have been isolated from marine and continental volcanic environments. Most hyperthermophiles belong to Archaea, the third domain of life, and are considered to be the most ancient of all extant life forms. Recent studies have revealed the presence of unusual sugar metabolic processes in hyperthermophilic archaea, for example, a modified Embden-Meyerhof pathway, that has so far not been observed in bacteria and eucarya. Several novel enzymes, such as ADP-dependent glucokinase, ADP-dependent phosphofructokinase, glyceraldehyde-3-phosphate ferredoxin oxidoreductase, phosphoenolpyruvate synthase, pyruvate : ferredoxin oxidoreductase, and ADP-forming acetyl-CoA synthetase, have been found to be involved in a modified Embden-Meyerhof pathway of the hyperthermophilic archaeon Pyrococcus furiosus. In addition, a unique mode of ATP regeneration has been postulated to exist in the pathway of P. furiosus. The metabolic design observed in this microorganism might reflect the situation at an early stage of evolution.
嗜热菌是一类最适生长温度高于80摄氏度的微生物。已从海洋和陆地火山环境中分离出60多种嗜热菌。大多数嗜热菌属于古菌域，即生命的第三个域，被认为是所有现存生命形式中最古老的。最近的研究揭示了嗜热古菌中存在不寻常的糖代谢过程，例如一种改良的糖酵解途径，迄今为止在细菌和真核生物中尚未观察到。已发现几种新型酶，如ADP依赖性葡萄糖激酶、ADP依赖性磷酸果糖激酶、甘油醛-3-磷酸铁氧还蛋白氧化还原酶、磷酸烯醇丙酮酸合酶、丙酮酸：铁氧还蛋白氧化还原酶和ADP形成型乙酰辅酶A合成酶，参与嗜热古菌激烈火球菌的改良糖酵解途径。此外，推测激烈火球菌的途径中存在一种独特的ATP再生模式。在这种微生物中观察到的代谢设计可能反映了进化早期的情况。
