ON THE RELATIONSHIP BETWEEN BACTERIAL-CELL INTEGRITY AND RESPIRATORY-CHAIN ACTIVITY - A FLUORESCENCE ANISOTROPY STUDY

The fluorescence anisotropy (r) of intracellular NADH was used as a pa rameter responsive to changes in the intracellular structure and cell integrity of bacteria. When Micrococcus luteus cells were subjected to gentle lysis with lysozyme in the presence of saturating concentratio ns of respiratory substrates, the respiratory rate was stimulated tran siently followed by the decrease in respiratory chain activity correla ted with r value reduction. It is concluded that immediately following lysozyme treatment, the respiratory chain in situ then exists in a st ate characterized by a maximal activity, until such time as cell integ rity is disturbed. The preservation of a high respiratory activity in lysed bacterial cells pretreated with glutaraldehyde confirms this. (C ) 1994 Academic Press, Inc.