Determination of metabolic activity and detection of microbial cells by electrophysical analysis

Abstract number: r2068

Ignatov  O.V., Guliy  O.I., Bunin  V.D., Ignatov  V.V.

Objectives and methods: 

Measurement of electrophysical properties of microbial cells may be used for creation of new kind of biosensor systems. There were investigated the microbial cells of some strains with preliminary metabolic enzyme system of toxic compounds. These processes conduce to the redistribution of the charges in the microbial cells and may be register by electro-optical (EO) methods. The electro-optical analyzer (ELUS EO), which has been developed at the State Research Center for Applied Microbiology, Obolensk, Russia, was used as the basic instrument for electro-optical measurements EO analysis is based on the recording of changes in optical characteristics of cell suspensions under the orienting effect of an electric field. Redistribution of the charges in the microbial cells may be used for determination of substrates of enzyme reaction and finally for determination of substrate concentration.


Same approach may be used for studies of microbial cells and some biological agents (antibodies and phages) binding. Since the AC electrokinetic effects depend on dielectric properties of bioparticles, their composition, morphology, phenotype, the medium, and the frequency of applied electrical field, the EO properties of cell suspensions were used for discrimination of bacteria before and after selective binding with antibodies. There were shown the determination of the presence of particular bacteria within a mixed sample may be achieved by selection and matching of antibodies specific to individual bacterium types and by comparing spectra of bacterium in the presence and in the absence of specific antibody. Same principles were used for investigations of bacteria – phage interaction. Integration of the electro-optical approach with a bioselective binding agents has the following advantages: 1) bacteria from biological samples need not be purified and 2) exogenous substrates and mediators are not required for detection.


So electro-optical analysis of cell suspensions provide new opportunities for creation of new biosensor methods in biotechnology, environmental control and medicine.

This work was supported ISTC grant 615 and 3170PDG.

Session Details

Date: 01/08/2007
Time: 00:00-00:00
Session name: XXIst ISTH Congress
Location: Oxford, UK
Presentation type:
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