Flow-injection fluorometric quantification of pyruvate using co-immobilized pyruvate decarboxylase and aldehyde dehydrogenase reactor: Application to measurement of acetate, citrate and l-lactate.
A flow-injection system for the quantification of pyruvate based on the coupled reactions of pyruvate decarboxylase (PDC) and aldehyde dehydrogenase (AlDH) was conceived and optimized. A co-immobilized PDC and AlDH reactor was introduced into the flow line. Sample and reagent (NAD(+)) were injected into the flow line by an open sandwich method and the increase of NADH produced by the immobilized-enzyme reactor was monitored fluorometrically at 455nm (excitation at 340nm). Linear relationships between the responses and concentrations of pyruvate were observed in the ranges of 2.0x10(-5) to 1.5x10(-3)M at the flow rate of 1.0mlmin(-1) and 5.0x10(-6) to 1.0x10(-3)M at the flow rate of 0.5mlmin(-1). The relative standard deviation for 10 successive injections was 0.95% at the 1.0mM level. This FIA system for pyruvate was applied to the measurement of acetate, citrate and l-lactate.
Tsukatani
Tadayuki
T
Biotechnology and Food Research Institute, Fukuoka Industrial Technology Center, Kurume 839-0861, Japan.
Matsumoto
Kiyoshi
K