Selectivity enhancement of an Escherichia coli bacterial electrode using enzyme and transport inhibitors

Abstract

Abstract The feasibility of using specific enzyme and transport inhibitors to minimize the glutamine response of a potentiometric microbial sensor is demonstrated. The glutamine response of a bacterial electrode prepared with Escherichia coli as the biocatalyst in conjunction with an ammonia gas‐sensing electrode was greatly reduced by treating the electrode with the enzyme inhibitor 6‐diazo‐5‐oxo‐ L ‐norleucine (DONL) and the transport inhibitor γ‐ L ‐glutamylhydrazide. Each inhibitor effectively decreased glutamine response to a level sufficiently low to be considered negligible in clinical studies. Although the sensor ultimately recovered from the effects of a single exposure to an inhibitor, continuous exposure at an optimum concentration maintained a low response to glutamine. Furthermore, the treatment of the sensor with both inhibitors simultaneously resulted in a negligible response to glutamine of <1 mV, indicating that both inhibitors are necessary for optimum inhibition of glutamine response. This approach is promising as a means of enhancing the selectivity of microbial sensors.

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Identifiers

DOI

10.1002/bit.260300414

Journal

Biotechnology and Bioengineering

Year

1987