Cox R P, Marling N
Institute of Biochemistry, Odense University, Denmark.
Antonie Van Leeuwenhoek. 1992 Nov;62(4):291-7. doi: 10.1007/BF00572597.
Oxygen uptake by washed cell suspensions of Bifidobacterium bifidum DSM 20082 was studied by using spectrophotometric measurements of the degree of oxygenation of added myoglobin as a measure of the concentration of dissolved O2. The absorbance changes during consumption of O2 in a closed reaction vessel were analysed by computer to obtain estimates of the changes in dissolved O2 concentration with time. These were then used to calculate the rate of O2 uptake as a function of the dissolved O2 concentration. The cell suspensions showed Michaelis-Menten kinetics with an apparent Km value of 0.06 microM O2. Cell-free extracts contained a soluble NADH oxidase activity with a stoichiometry corresponding to the reduction of O2 to H2O and with a high affinity for O2.
通过使用分光光度法测量添加的肌红蛋白的氧化程度来衡量溶解氧浓度，研究了两歧双歧杆菌DSM 20082洗涤细胞悬液的氧气摄取情况。在封闭反应容器中消耗氧气期间的吸光度变化由计算机分析，以获得溶解氧浓度随时间变化的估计值。然后将这些值用于计算氧气摄取速率作为溶解氧浓度的函数。细胞悬液呈现米氏动力学，表观Km值为0.06微摩尔氧气。无细胞提取物含有一种可溶性NADH氧化酶活性，其化学计量对应于将氧气还原为水，并且对氧气具有高亲和力。
