Surface characterization and on-line activity measurements of microorganisms by capillary zone electrophoresis

Capillary zone electrophoresis (CZE) was applied to the electrophoretic cha racterization for microorganisms. The electrophoretic peaks detected using light scattering phenomena were characteristic of the microorganisms used. The electrophoretic mobility (mu) evaluated by CZE was in good agreement wi th that obtained by classical electrophoresis of microorganisms. The migrat ion time was reproducible and depended on the ionic strength (I). Analysis of the mu vs. I relationship provided information regarding the charge dens ity and the hardness of the microbial cell surface. The redox enzymatic act ivity of microorganisms was also evaluated by CZE using a running buffer co ntaining a corresponding substrate and an appropriate exogenous electron ac ceptor. A decrease in the concentration of the electron acceptor due to mic robial activity can be simultaneously monitored during the electrophoretic process without significant modification of the CZE instrument. Effects of some chemical treatments of microbial cells were also studied using this te chnique. (C) 1999 Elsevier Science B.V. All rights reserved.