O'Brien R W
Aust J Biol Sci. 1977 Dec;30(6):553-8. doi: 10.1071/bi9770553.
Pseudomonas putida grew at the same rate with the same molar growth yield on D-, L, or DL-lactate as the sole source of carbon for growth. D- and L- lactate were utilized simultaneously and at the same rate when the organism was grown on DL-lactate (ratio of D isomer to L isomer of 1:1). Growth on either isomer alone, or in combination, caused the induction of both a D-lactate, and an L-lactate dehydrogenase. Both enzymes were particulate and used dichlorophenolindophenol, or oxygen, but not NAD, as electron acceptor, and were inhibited by cyanide when oxygen was the electron acceptor. The pH optimum for the D-lactate dehydrogenase was about 6.5, and for the L-lactate dehydrogenase was about 8.0. The D-lactate dehydrogenase was more heat-sensitive than the L-lactate dehydrogenase. The stoichiometry of both enzyme reactions was the same with 2 mol of lactate dehydrogenase. The stoichiometry of both enzyme reactions was the same with 2 mol of lactate being oxidized by 1 mol of oxygen to form 2 mol of pyruvate. No lactate racemase was detected in the cell extracts.
恶臭假单胞菌以D-、L-或DL-乳酸作为唯一碳源生长时，其生长速率相同，摩尔生长产率也相同。当该微生物在DL-乳酸（D-异构体与L-异构体的比例为1:1）上生长时，D-乳酸和L-乳酸同时且以相同的速率被利用。单独以任何一种异构体或以组合形式生长都会诱导产生D-乳酸脱氢酶和L-乳酸脱氢酶。这两种酶都是颗粒状的，以二氯酚靛酚或氧气作为电子受体，但不以NAD作为电子受体，当氧气作为电子受体时会被氰化物抑制。D-乳酸脱氢酶的最适pH约为6.5，L-乳酸脱氢酶的最适pH约为8.0。D-乳酸脱氢酶比L-乳酸脱氢酶对热更敏感。两种酶反应的化学计量相同，2摩尔乳酸被1摩尔氧气氧化形成2摩尔丙酮酸。在细胞提取物中未检测到乳酸消旋酶。
