Sano K, Otani M, Uehara R, Kimura M, Umezawa C
Laboratory of Biochemistry, School of Pharmacy, Kobe-Gakuin University, Hyogo.
Microbiol Immunol. 1988;32(9):877-85. doi: 10.1111/j.1348-0421.1988.tb01449.x.
Metabolic events involved in energy metabolism were studied in order to evaluate the ATP-forming ability of Bacillus megaterium QM B1551 spores at the very early stage of germination. When heat-activated spores were germinated on glucose as a sole substrate, its oxidation into gluconate (catalyzed by glucose dehydrogenase, EC 1.1.1.47), the accompanying NADH formation, oxygen uptake, and RNA synthesis were initiated immediately after germination, even when anaerobic breakdown of 3-phosphoglycerate (an ATP source for spores) and the subsequent glucose metabolism via the phosphorylating pathway were impaired by potassium fluoride (KF). In contrast, fructose metabolism and the accompanying metabolic events did not begin until a few minutes after triggering of germination, and those events were entirely abolished by KF, indicating that fructose metabolism is initiated exclusively via its phosphorylation by the ATP derived from endogenous 3-phosphoglycerate. Thus those results provided further evidence for our previous proposal (Otani et al (1987) Microbiol. Immunol. 31: 967-974; Sano et al (1988) Biochem. Biophys. Res. Commun. 151: 48-52) that the first molecules of ATP in germinating spores can be efficiently generated via aerobic oxidation of NADH, which is formed by glucose dehydrogenase. Fluorescence monitoring of NADH in germinating spores also supported this conclusion.
为了评估巨大芽孢杆菌QM B1551孢子在萌发早期形成ATP的能力，对能量代谢中涉及的代谢事件进行了研究。当热激活的孢子在以葡萄糖为唯一底物的条件下萌发时，即使3 - 磷酸甘油酸（孢子的一种ATP来源）的厌氧分解以及随后通过磷酸化途径的葡萄糖代谢受到氟化钾（KF）的抑制，其氧化为葡萄糖酸（由葡萄糖脱氢酶催化，EC 1.1.1.47）、伴随的NADH形成、氧气摄取和RNA合成在萌发后立即开始。相比之下，果糖代谢以及伴随的代谢事件直到萌发触发几分钟后才开始，并且这些事件完全被KF消除，这表明果糖代谢完全是通过内源性3 - 磷酸甘油酸产生的ATP对其进行磷酸化而启动的。因此，这些结果为我们之前的提议（Otani等人（1987年）《微生物学与免疫学》31: 967 - 974；Sano等人（1988年）《生物化学与生物物理研究通讯》151: 48 - 52）提供了进一步的证据，即萌发孢子中的第一批ATP分子可以通过葡萄糖脱氢酶形成的NADH的有氧氧化有效产生。对萌发孢子中NADH的荧光监测也支持了这一结论。
