Determination of L-glutamate using flow injection analysis with immobilized L-glutamate oxidase reactor.
L-Glutamate oxidase (GOD) and horseradish peroxidase (HRP) were covalently coupled on alkylamine pretreated controlled pore glass (CPG) by means of glutaraldehyde. The immobilized enzymes were packed into a teflon tube and used in flow injection analysis (FIA) system for L-glutamate determination. A good linearity range was obtained at 0.1-2.0 mM, and the coefficient of variation was 0.7% (n = 8). More than 80 samples were measured within an hour. The stability of the immobilized GOD reactor was good, retaining 50% of its initial activity after 4 months storage in buffer at 4 degrees C. When the concentration of L-glutamate remained lower than 2.5 mM, the determination of L-glutamate in this system was not affected by pH and temperature within the range of 6.0-8.0 and 20-35 degrees C, respectively. The system was applied to determine L-glutamate in broth samples during L-glutamate fermentation and good correlations were achieved between results obtained with the FIA system, L-glutamate oxidase kit and Warburg's method.
Li
Q
Q
Research Institute of Biochemical Engineering, East China University of Science and Technology, Shanghai.
Ye
B
B
Zhang
S
S
Yu
J
J
D000594:Amino Acid Oxidoreductases / Q000378:metabolism*; D002138:Calibration; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000378:metabolism*; D017022:Flow Injection Analysis; D018698:Glutamic Acid / Q000032:analysis*; D006735:Horseradish Peroxidase / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D010710:Phosphates / Q000494:pharmacology; D013696:Temperature
D004800:Enzymes, Immobilized; D010710:Phosphates; D018698:Glutamic Acid; D006735:Horseradish Peroxidase; D000594:Amino Acid Oxidoreductases; C023061:L-glutamate oxidase