Amperometric flow-ikiection analytical system for quantitation of low L-lysine concentration was described. Llysine-a-oxidase from Trichoderme sp. was immobilized by covalent linking on silica gel. The ahift in oxygen concentration during enzymatic reaction was detected with a Clark membrane electrode. The rate of oxygen consumption was linearly dependent on Llysine concentration over the 0.20 -5,5 d. Response time was 14 s. the total assay the about 2 min. The influences of pH, ionic strength and nature of the buffer on enzyme catalytic activity were tested. The analysis conditions were optimized. The immobilized L-1yaine-U-oxidase retained the catalytic activity for about 5 months.

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A biosensor to quantify L-proline within 10(-5)-10(-3) mole/L concentration is described. Immobilized Pseudomonas sp. cells grown in a medium containing L-proline as the only source of carbon and nitrogen were used to create the biosensor. The cells oxidized L-proline specifically consuming O2 and did not react with other amino acids and sugars. The change in oxygen concentration was detected with a Clark oxygen membrane electrode. The cells were immobilized by entrapment in polyvinyl alcohol (PVA) cryogel. The resultant biocatalyst had a high mechanical strength and retained its L-proline-oxidizing ability for at least two months.